WO1996025767A2 - Phonon resonator and method for its production - Google Patents
Phonon resonator and method for its production Download PDFInfo
- Publication number
- WO1996025767A2 WO1996025767A2 PCT/US1996/002052 US9602052W WO9625767A2 WO 1996025767 A2 WO1996025767 A2 WO 1996025767A2 US 9602052 W US9602052 W US 9602052W WO 9625767 A2 WO9625767 A2 WO 9625767A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- isotope
- phonon
- layer
- doped region
- phonons
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 52
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 230000003287 optical effect Effects 0.000 claims abstract description 81
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 68
- 239000010703 silicon Substances 0.000 claims abstract description 65
- 230000003993 interaction Effects 0.000 claims abstract description 44
- 238000012546 transfer Methods 0.000 claims abstract description 12
- 239000000463 material Substances 0.000 claims description 111
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 65
- 239000004065 semiconductor Substances 0.000 claims description 35
- 230000005669 field effect Effects 0.000 claims description 17
- 230000006870 function Effects 0.000 claims description 15
- 230000000737 periodic effect Effects 0.000 claims description 13
- 239000004020 conductor Substances 0.000 claims description 12
- 230000005855 radiation Effects 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 10
- 230000001427 coherent effect Effects 0.000 claims description 9
- 238000004891 communication Methods 0.000 claims description 9
- 238000001182 laser chemical vapour deposition Methods 0.000 claims description 7
- 229910044991 metal oxide Inorganic materials 0.000 claims description 7
- 150000004706 metal oxides Chemical class 0.000 claims description 7
- 230000037361 pathway Effects 0.000 claims description 7
- 238000005229 chemical vapour deposition Methods 0.000 claims description 6
- 238000001803 electron scattering Methods 0.000 claims description 6
- 230000006872 improvement Effects 0.000 claims description 6
- 238000004871 chemical beam epitaxy Methods 0.000 claims description 5
- 238000009792 diffusion process Methods 0.000 claims description 5
- 239000002019 doping agent Substances 0.000 claims description 4
- 238000001451 molecular beam epitaxy Methods 0.000 claims description 4
- 238000009377 nuclear transmutation Methods 0.000 claims description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 238000002310 reflectometry Methods 0.000 claims description 3
- 238000005119 centrifugation Methods 0.000 claims description 2
- 238000004821 distillation Methods 0.000 claims description 2
- 238000002848 electrochemical method Methods 0.000 claims description 2
- 230000005274 electronic transitions Effects 0.000 claims description 2
- 238000000605 extraction Methods 0.000 claims description 2
- 241000238366 Cephalopoda Species 0.000 claims 1
- 238000003491 array Methods 0.000 claims 1
- 230000007704 transition Effects 0.000 abstract description 46
- 238000010521 absorption reaction Methods 0.000 description 25
- 230000007246 mechanism Effects 0.000 description 13
- 239000007787 solid Substances 0.000 description 11
- 235000012431 wafers Nutrition 0.000 description 11
- 230000006798 recombination Effects 0.000 description 10
- 238000005215 recombination Methods 0.000 description 10
- 230000002269 spontaneous effect Effects 0.000 description 10
- 238000000926 separation method Methods 0.000 description 9
- 229910000077 silane Inorganic materials 0.000 description 9
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 8
- 239000013078 crystal Substances 0.000 description 8
- 238000005372 isotope separation Methods 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 238000010494 dissociation reaction Methods 0.000 description 7
- 230000005593 dissociations Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 238000004508 fractional distillation Methods 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 230000000155 isotopic effect Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 230000008878 coupling Effects 0.000 description 5
- 238000010168 coupling process Methods 0.000 description 5
- 238000005859 coupling reaction Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 230000017525 heat dissipation Effects 0.000 description 5
- 230000005428 wave function Effects 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000000151 deposition Methods 0.000 description 4
- 239000003574 free electron Substances 0.000 description 4
- 239000012071 phase Substances 0.000 description 4
- 241000894007 species Species 0.000 description 4
- 238000013459 approach Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 230000005284 excitation Effects 0.000 description 3
- 230000007717 exclusion Effects 0.000 description 3
- 238000011065 in-situ storage Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 238000005468 ion implantation Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 229910052691 Erbium Inorganic materials 0.000 description 2
- 229910003910 SiCl4 Inorganic materials 0.000 description 2
- 230000005699 Stark effect Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 229910021419 crystalline silicon Inorganic materials 0.000 description 2
- 238000013500 data storage Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 2
- 230000005283 ground state Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000010348 incorporation Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 230000001404 mediated effect Effects 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- FDNAPBUWERUEDA-UHFFFAOYSA-N silicon tetrachloride Chemical compound Cl[Si](Cl)(Cl)Cl FDNAPBUWERUEDA-UHFFFAOYSA-N 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 230000002459 sustained effect Effects 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 229910004014 SiF4 Inorganic materials 0.000 description 1
- 229910003811 SiGeC Inorganic materials 0.000 description 1
- 229910003818 SiH2Cl2 Inorganic materials 0.000 description 1
- 229910000577 Silicon-germanium Inorganic materials 0.000 description 1
- 241000282485 Vulpes vulpes Species 0.000 description 1
- LEVVHYCKPQWKOP-UHFFFAOYSA-N [Si].[Ge] Chemical compound [Si].[Ge] LEVVHYCKPQWKOP-UHFFFAOYSA-N 0.000 description 1
- ROZUYFMKAHJYEW-UHFFFAOYSA-N [Sn].[Ge].[Si].[C] Chemical compound [Sn].[Ge].[Si].[C] ROZUYFMKAHJYEW-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000002772 conduction electron Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- BUMGIEFFCMBQDG-UHFFFAOYSA-N dichlorosilicon Chemical compound Cl[Si]Cl BUMGIEFFCMBQDG-UHFFFAOYSA-N 0.000 description 1
- 230000003467 diminishing effect Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005401 electroluminescence Methods 0.000 description 1
- 238000010893 electron trap Methods 0.000 description 1
- 239000012776 electronic material Substances 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 230000033001 locomotion Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000005312 nonlinear dynamic Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000005424 photoluminescence Methods 0.000 description 1
- 238000006303 photolysis reaction Methods 0.000 description 1
- 238000005381 potential energy Methods 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000005610 quantum mechanics Effects 0.000 description 1
- 229910002059 quaternary alloy Inorganic materials 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000002128 reflection high energy electron diffraction Methods 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000001004 secondary ion mass spectrometry Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- ABTOQLMXBSRXSM-UHFFFAOYSA-N silicon tetrafluoride Chemical compound F[Si](F)(F)F ABTOQLMXBSRXSM-UHFFFAOYSA-N 0.000 description 1
- GOLXNESZZPUPJE-UHFFFAOYSA-N spiromesifen Chemical compound CC1=CC(C)=CC(C)=C1C(C(O1)=O)=C(OC(=O)CC(C)(C)C)C11CCCC1 GOLXNESZZPUPJE-UHFFFAOYSA-N 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 239000002887 superconductor Substances 0.000 description 1
- 230000036964 tight binding Effects 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 238000001845 vibrational spectrum Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/04—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction
- H01L33/06—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction within the light emitting region, e.g. quantum confinement structure or tunnel barrier
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
- H01L31/0352—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/12—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/015—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on semiconductor elements with at least one potential jump barrier, e.g. PN, PIN junction
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/062—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes
- H01S5/06203—Transistor-type lasers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
- H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/3027—IV compounds
- H01S5/3031—Si
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/32—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures
- H01S5/3223—IV compounds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/32—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures
- H01S5/3223—IV compounds
- H01S5/3224—Si
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/50—Amplifier structures not provided for in groups H01S5/02 - H01S5/30
Definitions
- Optical communication systems offer a potential solution to the interconnect problem, but development efforts have been hampered by the difficulties associated with integrating efficient light sources into available silicon circuits.
- Silicon itself like the other members of its periodic-table family (group IN), has limited optical capabilities due to its centrosymmetric crystal structure and an indirect band gap, which prohibits photon emission via efficient, band-to-band radiative transmission (see below).
- Much effort has been directed at circumventing the selection rules that forbid band-to-band radiative transmission in indirect bandgap semiconductors, in order to develop semiconducting materials with improved optical properties (Iyer et al. Science 260:40-46, 1993).
- One approach has been to introduce suitable impurities into the group IV lattice.
- Tight binding of an exciton (an electron-hole pair) to an impurity can provide efficient radiative transmissions if a sufficient volume of impurities has been introduced.
- the most successful of these efforts have involved isoelectronic complexes and the rare-earth dopant Erbium.
- Erbium like other radiative impurity complexes, is difficult to introduce in a concentration sufficient to provide optical gain.
- a widely studied (but poorly understood) mechanism for light emission occurs in silicon that has undergone an electrochemical etching process (Iyer et al. supra).
- the etch produces a porous structure with nanometer-size particles that, upon passivation, provides efficient, visible photoluminescence.
- Samples of etched silicon have also been excited in electroluminescence, and have attracted some interest for display devices.
- LEDs have been fabricated using silicon carbide.
- optical amplifiers e.g. lasers
- indirect bandgap materials for a discussion of the underlying reasons.
- the improved materials should be compatible with present-day electronic materials (e.g. silicon).
- the present invention provides an improved material in which optical, electronic, and/or heat dissipation characteristics are modified because certain electron-phonon interactions are enhanced or suppressed in the material.
- the present invention provides an indirect bandgap material that functions as a resonator for phonons of desired wavenumbers.
- the phonon resonator of the present invention displays increased photon emission or absorption capability relative to known indirect bandgap materials.
- the present phonon resonator has enhanced electrical properties, such as electrical conductivity.
- the phonon resonator of the present invention can also show improved thermal conductivity characteristics, and can be incorporated into electronic devices to provide improved heat transfer.
- the present invention also provides an isotope superlattice that is a phonon resonator.
- the phonon resonator of the present invention can be incorporated into any of a variety of different optical devices such as, for example, LEDs and lasers.
- the present phonon resonator can be utilized, for example, in optical communications, data storage, printing, uv-light emission, infrared lasers, etc..
- Other embodiments of the phonon resonator of the present invention have enhanced electrical conductivity and can be utilized in electrical applications such as, for example, superconducting applications.
- the present invention also provides methods of fabricating an isotope superlattice that is a phonon resonator.
- the phonon resonator of the present invention is a structure of substantially periodically varying density, which structure comprises at least one first region of a first density; and at least one second region of a second density, the first and second regions being adjacent one another and alternating in the structure so that the structure has a substantially periodically varying density.
- the period of the structure is selected such that the structure is substantially resonant for phonons of appropriate wavevector to participate in electron-phonon interactions (e.g. phonons of appropriate wavevector to participate in radiative electronic transitions, phonons of appropriate wavevector to participate in interzone and/or intervalley scattering of conduction band electrons).
- the phonon resonator of the present invention is a structure having degenerate conduction band valleys and substantially periodic variations in material composition so that scattering of electrons between the degenerate conduction band valleys is enhanced relative to intervalley electron scattering in a structure that lacks the substantially periodic variations.
- the density or material composition of the structure varies periodically in more than one dimension; in other embodiments, each region comprises a layer, so that the density or material composition of the structure varies periodically in only one dimension.
- the phonon resonator is a layered structure comprising an isotope superlattice in which each layer is enriched for one isotope of an element. Most preferably, the layers are enriched for different isotopes of the same element, preferably silicon. In some preferred embodiments of a silicon isotope superlattice of the present invention, the superlattice has a period that is an integer multiple of five atomic layers; in alternate preferred embodiments, the period is an integer multiple of ten atomic layers.
- the phonon resonator of the present invention in some embodiments, is also resonant for (directional or coherent) phonons that are generated by stimulated phonon emission, so that the resonator provides accelerated heat transfer.
- the phonon resonator provides a stochastic phonon resonance.
- the present invention also provides various devices incorporating a phonon resonator.
- the invention provides, among other things, a light-emitting device. comprising a phonon resonator, a first electrode disposed on a first side of the structure; and a second electrode disposed on a second side of the structure, the second side being opposite the first side. At least one of the electrodes can be transparent if desired.
- the light-emitting device of the present invention can include a p-doped region and an n-doped region, and may function as a light- emitting diode (LED).
- the p- and n-doped regions of the light-emitting device of the present invention may have a higher bandgap than does the phonon resonator, so that electrons and holes are confined within the phonon resonator.
- the light- emitting device of the present invention preferably includes a dielectric waveguide, most preferably formed by the p-doped region and the n-doped region, each having a refractive index higher than that of the structure.
- the light-emitting device of the present invention is a laser (e.g. a cleaved facet reflection, distributed feedback, and/or vertical cavity surface emitting).
- the present invention also provides devices selected from the group consisting of light emitting devices, light emitting diodes, laser diodes, cleaved facet reflection lasers, distributed feedback lasers, vertical cavity surface emitting lasers, optical detectors, optical modulators, non-linear optical devices, electrical conductors, planar transformers, diodes, bipolar transistors, field-effect transistors, integrated circuits, SQUEDs, Josephson junctions, transducers, and microwave detectors, that are improved over conventional devices because they incorporate a phonon resonator that is substantially resonant for phonons of appropriate wavevector to participate in phonon-electron interactions.
- the present invention also provides a method for producing a phonon resonator comprising the step of producing a structure of substantially periodically varying density comprising at least one first region or layer of a first density; and at least one region or second layer of a second density, the first and second regions or layers being adjacent one another and alternating in the structure so that the structure has a substantially periodically varying density, the period of the structure being selected such that the structure is substantially resonant for phonons of appropriate wavevector to participate in electron-phonon interactions.
- the method of the present invention involves producing an isotope superlattice by separating isotopes; and assembling the superlattice.
- the steps of separating and assembling are performed separately.
- the steps of separating and assembling are performed simultaneously.
- an isotope superlattice of the present invention is produced using laser-assisted chemical vapor deposition.
- Figure 1 is a schematic diagram of the energy bands in a solid.
- Figure 2 is an energy vs. momentum diagram for a direct bandgap material.
- Figure 3 is an energy vs. momentum diagram for an indirect bandgap material.
- Figure 4 illustrates the three possible photon-electron interactions. Specifically, Figure 4 A illustrates absorption of a photon by an electron that can occupy one of only two energy states; Figure 4B illustrates spontaneous emission of a photon by an electron that can occupy one of only two energy states; and Figure 4C illustrates stimulated emission of a photon by an electron that can occupy one of only two energy states.
- Figure 5 is a schematic diagram of atoms arranged in a crystalline solid.
- Figure 6 depicts phonon-assisted radiative transitions in an indirect bandgap material.
- Figure 6 A illustrates spontaneous emission of a phonon as a result of an electron-phonon interaction that stimulates photon emission;
- Figure 6B illustrates stimulated phonon absorption;
- Figure 6C illustrates stimulated phonon emission.
- Figure 7 is a schematic design of a distributed feedback laser.
- Figure 8 is an energy vs. momentum diagram for silicon.
- Figure 9 shows a schematic diagram of a portion of a silicon isotope superlattice of the present invention.
- Figure 10 illustrates a light emitting device that utilizes a phonon resonator of the present invention.
- Figure 11 presents four embodiments (as Figures 11 A, 11B, 11C, and 11D) of a light-emitting device of the present invention.
- Figure 12 depicts a light-emitting diode (LED) of the present invention.
- Figure 13 depicts an LED of the present invention in which carrier confinement is achieved by means of a heterojunction.
- Figure 14 depicts and edge-emitting LED of the present invention.
- Figure 15 presents two embodiments (as Figures 15 A and 15B) of a laser diode of the present invention.
- Figure 15 A depicts a cleaved facet reflection laser.
- Figure 15B depicts a distributed feedback laser.
- FIG 16 depicts a Vertical Cavity Surface Emitting Laser (VECSEL) of the present invention.
- VECSEL Vertical Cavity Surface Emitting Laser
- Figure 17 and 18 depict alternate embodiments of an optical photodetector incorporating a phonon resonator of the present invention.
- Figure 19 depicts absorption and emission of a phonon by a conduction-band electron in a semiconductor material.
- Figure 20 depicts coherent absorption and emission of a phonon by a conduction-band electron in a semiconductor material.
- Figure 21 illustrates phonon-mediated exchange between two conduction- band electrons in a semiconductor solid.
- Figure 22 illustrates phonon-mediated exchange between electrons in different, degenerate conduction band minima in a single conduction band of a semiconductor material.
- Figure 23 presents a graph of the normalized electron pair potential as a function of the pair separation, measured in superlattice periods.
- the mean free path is 5 superlattice periods.
- Figure 24 is a graph showing the reduction in electron pair binding energy that occurs with decreasing electron mean free path.
- Figure 25 shows the electron pair binding energy as a function of the scattering potential for a fixed mean free path.
- Figure 26 depicts intervalley scattering of electrons in conduction band minima of neighboring Brillouin zones.
- Figure 27 shows a low-resistance electrical conductor of the present invention.
- Figure 28 depicts an electrical diode of the present invention.
- Figure 29 depicts a bipolar transistor of the present invention.
- Figure 30 depicts an n-type Junction Field Effect Transistor (JFET) of the present invention.
- Figure 31 depicts a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) of the present invention.
- MOSFET Metal Oxide Semiconductor Field Effect Transistor
- Figure 32 depicts an integrated circuit of the present invention.
- Figure 33 depicts a laser-assisted chemical vapor deposition method according to the present invention.
- the present invention is directed to a phonon resonator.
- the invention provides a phonon resonator of an indirect bandgap material, which phonon resonator is designed so that certain electronic, optical, and/or heat transfer properties of the material are enhanced.
- a phonon can be thought of as the minimum unit of vibrational energy allowed in accordance with principles of quantum mechanics.
- a phonon resonator is a structure that functions as a resonator for those vibrational excitations that behave as quantum mechanical vibrational wavepackets.
- a vibrational resonator requires coherent confinement, or feedback, of vibrational energy.
- an electromagnetic resonator that is, a structure that is resonant for electromagnetic waves
- a vibrational resonator can be produced by creating a structure having a periodic variation in material density, since material density determines the impedance of a vibrational wave.
- One aspect of the present invention involves the recognition that a vibrational resonator can be constructed to be resonant with certain phonon- electron interactions, so that the resonator provides a resonant enhancement of the phonons necessary for those interactions.
- phonon resonators have previously been described previously (see, for example, Klein IEEE J. of Quant. Elec. QE-22: 1760-1779, 1986)
- the present invention describes for the first time a phonon resonator that provides resonant enhancement of phonon-electron interactions, with resulting improvement in optical, electronic, and/or heat transfer properties in the material from which the resonator is constructed.
- the present invention provides the first example of a phonon resonator having a coupling length that is shorter than the phonon mean free path.
- the present invention encompasses indirect bandgap materials having enhanced optical properties.
- indirect bandgap materials having enhanced optical properties.
- FIG. 1 presents a schematic representation of a valence band 10 and a conduction band 20, separated by an "energy bandgap" 30 that corresponds to the range of impermissible energies between the valence 10 and conduction 20 bands.
- valence band For any given semiconductor solid, most of the energy states within the valence band are occupied by electrons, while most of the energy states within the conduction band are unoccupied. If, however, an electron in the valence band can acquire energy in excess of the energy of the bandgap, that valence band electron can occupy an energy state within the conduction band. When such a valence band electron is excited into the conduction band, that electron leaves behind a vacant energy state in the valence band.
- the vacant energy state is termed a "hole" , and may be considered as a particle having a positive charge equal in magnitude to the electron.
- Electrons in the conduction band typically occupy states near the conduction band minimum. Holes are generally present at the valence band maximum. Under certain circumstances, these electrons and holes can recombine, resulting in the emission of a photon, otherwise known as a "radiative transition. " To obtain a radiative transition, both energy and momentum must be conserved.
- Direct bandgap refers to the fact that the conduction band minimum and valence band maximum are aligned in these materials along the same momentum value.
- Figure 2 presents a graph of the energy (E) versus momentum (k) relationship of an electron in a direct bandgap solid.
- the region 37 of the graph in Figure 2 between curves E,. and - ⁇ designates impermissible energy and momentum values for electrons in the solid.
- Curve E c (the conduction band edge) designates permissible energy and momentum values for electrons in the conduction band
- curve -E ⁇ (the valence band edge) designates permissible energy and momentum values for electrons in the valence band.
- the energy difference between the conduction band minimum 22 of curve E c and valence band maximum 12 of curve -E- is the energy bandgap 31.
- the alignment of conduction band minimum and valence band maximum in direct bandgap materials allows radiative transitions because an electron 40 has the same momentum value both before (i.e. in the conduction band) and after (i.e. in the valence band) the transition (i.e. before and after recombination with hole 50).
- Radiative transitions are effectively forbidden for indirect bandgap materials because, as noted above, photons are only emitted when an electron in the conduction band recombines with a hole in the valence band, and energy and momentum are conserved. Because the valence band maximum 15 and conduction band minimum 25 are displaced relative to one another in indirect bandgap materials, an electron located near the conduction band minimum 25 cannot recombine with a hole near the valence band maximum 15 without violating the conservation of momentum requirement (recall that the emitted photon has insignificant momentum).
- FIG. 4 illustrates the three possible photon-electron interactions that can occur in semiconductor materials: "absorption” ( Figure 4A), “spontaneous emission” ( Figure 4B), and “stimulated emission” ( Figure 4C).
- an incident photon 61 having an energy equal to the energy difference between a high energy state E ⁇ and a low energy state E, . stimulates an electron 40 in the high energy state to return to the low energy state, releasing its energy in the form of a second photon 63 that is equal in energy and phase with the incident photon 61.
- optical gain which is proportional to where z is the distance along which an input signal propagates and g, the gain per unit length, is proportional to R, t - m -R, bs .
- R, m is tne rate at which photons are emitted by stimulated emission and R ⁇ , is the rate at which photons are absorbed.
- high optical gain requires that stimulated photon emission (Figure 4C) exceed absorption ( Figure 4A).
- a specified number of electrons must be excited into a high energy state from a low energy state, a phenomenon known as "population inversion".
- B 2 is a coefficient proportional to the rate at which photons are absorbed
- B 2 ⁇ is a coefficient proportional to the rate at which photons are generated by stimulated emission.
- a population inversion is achieved for photon energies satisfying the relationship: Eg ⁇ hv ⁇ e fC - € f v.
- the "quasi-Fermi energy" or intraband chemical potential gauges the population distribution in each band.
- a population inversion can be created by generating electron-hole pairs (i.e. by exciting electrons into the conduction band and thereby creating holes in the valence band).
- electron-hole pairs i.e. by exciting electrons into the conduction band and thereby creating holes in the valence band.
- direct bandgap materials such an increase in excited electron and hole density results in increased stimulated photon emission.
- indirect bandgap materials however, the inability of the excited electrons to readily recombine with holes limits the extent to which increased exciton population (i.e. increased electron-hole density) leads to increased stimulated emission.
- the so-called "free carrier absorption" also increases such that increased numbers of photons are absorbed by the electrons in the conduction band.
- stimulated emission typically does not exceed absorption in indirect bandgap materials.
- both spontaneous and stimulated radiative transitions are effectively forbidden in indirect bandgap materials because an electron located near the conduction band minimum of an indirect bandgap material cannot recombine with a hole near the valence band maximum without violating the conservation of momentum requirement.
- This problem can be overcome if the momentum necessary to allow a radiative transition can be provided by crystal lattice vibrations, or phonons.
- atoms in a crystal lattice can be modelled, qualitatively, as balls 70 attached to one another by springs 75.
- phonons correspond to the (quantized) vibrational motions of such balls propagating through the crystal as a wave.
- the interaction of a phonon with an electron in the conduction band can provide the necessary momentum to allow an "indirect” , or "phonon-assisted", transition of the electron into a hole in the valence band, resulting in emission of a photon.
- Figure 6 illustrates three different mechanisms for phonon-assisted radiative transitions in an indirect bandgap material.
- Figure 6 A depicts a phonon- assisted radiative transition involving spontaneous emission of a phonon 83.
- Figure 6B shows a mechanism involving stimulated phonon absorption
- Figure 6C depicts a mechanism involving stimulated phonon emission.
- both momentum and energy must be conserved in a radiative transition.
- the phonon provides the requisite change in momentum, (k 2 -k,), so momentum is conserved during recombination of an electron in the conduction band minimum with a hole in the valence band maximum. Consequently, a photon having an energy approximately equal to the bandgap is emitted.
- the emitted photon has an energy, E., that is equal to the bandgap minus (for those mechanisms involving phonon emission) or plus (for mechanisms involving phonon absorption) the phonon energy, ⁇ . That is:
- phonon resonator can be produced by making structure of periodically varying density, in which the vibrational energy (i.e. the phonon density) at the momentum necessary to produce an indirect optical transition is enhanced. Since, even at high frequencies, phonons are vibrational waves of masses (atoms) in a medium, changes in the mass density of the medium through which the phonons propagate can be used to increase the density of phonons of a desired momentum and energy, while diminishing those of other momenta and energies.
- a phonon resonator could or should be designed to be resonant for phonons of appropriate wavevector to participate in phonon-electron interactions.
- a phonon resonator according to the invention When a phonon resonator according to the invention is produced, radiative recombination events involving phonon absorption are enhanced in proportion to the ratio of the phonon density in the structure to the phonon density in a disordered (i.e. not having a periodically varying density) structure of the same material.
- a phonon resonator will achieve a high probability of indirect optical transitions if it is resonant for phonons of the appropriate momentum to participate in any of the recombination events depicted in Figure 6 (i.e. in recombination events involving spontaneous emission of a phonon, stimulated phonon absorption, and/or stimulated phonon emission).
- the probability of spontaneous emission is locally modified in a resonator.
- some locations in a resonator have a very high probability of spontaneous emission, while other locations have comparatively low probabilities.
- the present invention provides a material in which spontaneous phonon emission is enhanced.
- a resonator can also affect which energy and momenta are likely to attract spontaneously emitted phonons.
- both stimulated phonon absorption and stimulated phonon emission can be enhanced.
- the resonator may be able to support a nonequilibrium phonon population that maintains itself through stimulated phonon emission. This is achieved when the phonon generation rate is equal to the scattering loss for the structure.
- Photons produced by a mechanism involving phonon absorption therefore have an energy greater than the bandgap energy. Such photons can readily be re-absorbed by the structure.
- photons produced by a mechanism involving phonon emission have an energy less than that of the bandgap and cannot readily be reabsorbed by the structure.
- optical gain is more readily achieved in a phonon resonator in which photon emission occurs through a process involving phonon emission rather than phonon absorption.
- the enhancement of radiative transitions in a phonon resonator is equal to the number of phonons per vibrational mode of the resonator.
- a structure is created having alternating layers of relatively high mass density and relatively low mass density.
- the layered structure is resonant for phonons having a wavelength such that an integral number of half -wavelengths fits into the lattice period; phonons having other wavelengths propagate through the structure without any resonant reflection.
- One consequence of a strong resonance is an increase in the stored energy (i.e. phonon density) at the center of the structure.
- the period, ⁇ L of the layered structure of the present invention is chosen to provide a resonant Bragg reflection for phonons having the momentum necessary to participate in indirect transitions.
- a distributed feedback laser includes alternating layers of first 73 and second 77 materials having first and second indices of refraction. As light propagates through this layered medium (e.g. from left to right in Figure 7), small reflections are generated at each interface (i,....-,. in Figure 7). If each reflected wave is in phase, it reinforces the others so that the total net reflection is high and a resonance (e.g. a Bragg resonance) occurs. Also, the propagation of light through the material results in stimulated emission of additional photons that also propagate through the material and can be reflected at the layer interfaces. As discussed above, "lasing" occurs when stimulated emission exceeds absorption in the material. A distributed feedback laser will continue to lase as long as electrons are continually pumped into excited energy states.
- the layered structure of the present invention operates in a similar fashion to the distributed feedback laser except that, instead of photons, it is phonons having the desired momentum that propagate through the material.
- the layered structure will only function as an effective resonator if the phonon mean free path is sufficiently long that the phonon scatters very little while passing through the structure.
- the mean free path of the phonon will be sufficiently long if the coupling coefficient, ⁇ p , between the incident and reflected phonons is greater than the inverse phonon scattering length, ⁇ p .
- the layered structure of the present invention may be realized in a crystalline solid, for example by alternating thin, isotopically-enriched layers- i.e. by making an "isotope superlattice.
- An "isotopically enriched" layer is a layer having a concentration of an isotope which is greater than the concentration of the isotope found naturally.
- silicon is primarily composed of three isotopes in the following compositions, 92.2% Si 28 , 4.7% Si 29 and 3J % Si 30 .
- an isotopically-enriched layer of Si 28 is a layer that contains the isotope Si 28 in a concentration more than 92.2% of the atoms of that layer.
- isotopically enriched layers of Si 29 and Si 30 are layers that have atomic concentrations of these isotopes that exceed 4.7% and 3.1 % , respectively.
- Isotope superlattices are known in the art (see, for example, Berezin Solid State Comm. 65:819-821, 1988; Berezin J. Phys. C. 20:L219-L221 , 1987; Fuchs Sup. and Microstruct. 13: 447-458, 1993; Haller GADEST, '93).
- isotope superlattices can be engineered to be phonon resonators that are resonant for phonons of appropriate wavevector to participate in phonon-electron interactions.
- the larger the difference in mass density within the structure the better the resonance.
- An isotope superlattice having alternating thin layers of Si 28 and Si 29 achieves a little over 3 % modulation of mass density. Alternating Si 28 with Si 30 layers provides over 6% modulation.
- Crystalline silicon exhibits an indirect bandgap, as shown in Figure 8, in which the conduction band minimum is sixfold degenerate along the (100) direction, and occurs at approximately eight-tenths of the distance to the zone edge.
- a is 4 atomic layers.
- the period of a silicon isotope superlattice of the present invention therefore follows the relationship:
- ⁇ L 5m atomic layers.
- superlattices of the form Si 28 n Si 30 5 ⁇ .. n , for n t 0, will provide a resonance for phonons capable of participating in an indirect transition.
- Any silicon isotope superlattice having a period that is an integer multiple of 5 atomic layers will satisfy the Bragg resonance condition, using higher order scattering.
- Figure 9 shows a schematic representation of a portion of a silicon isotope superlattice of the present invention.
- the increased phonon density associated with an isotope superlattice of the present invention may serve to increase the exciton stability.
- Free electrons have a lifetime (the time required for an electron to recombine nonradiatively with a trap) on the order of one microsecond or less, while excitonic electrons have radiative lifetimes much longer than one microsecond.
- the radiative transition rate is increased in accordance with the present invention, the exciton radiative lifetime is reduced. Accordingly, fewer conduction electrons exist as free electrons, and more electrons are available for exciton formation.
- an optical modulator based on the Stark effect can be made of indirect bandgap materials.
- a phonon resonator of the present invention may be incorporated into a light-emitting device, as depicted in Figure 10.
- the phonon resonator 100 is positioned between electrodes 110 and 120.
- Electrodes 110 and 120 may comprise semiconductor materials or conductor materials. These electrodes 110 and 120 serve to facilitate formation of a population inversion in the phonon resonator 100 by injection and/or confinement of carriers (i.e. electrons or holes) in this region.
- the phonon resonator 100 is an isotope superlattice.
- Figure 11 presents four embodiments of a light-emitting device of the present invention in which an isotope superlattice 86 is positioned between electrodes 110 and 120.
- the device structure includes an electrode layer 120 formed on a substrate 130.
- the isotope superlattice 86 consists of alternating isotopically-enriched layers 86 A and 86B and is disposed on electrode 120.
- Second electrode 110 is formed on isotope superlattice 86.
- electrodes 110 and 120 may be disposed laterally on opposite sides of isotope superlattice 86.
- a light-emitting device of the present invention may be constructed to be an edge-emitter (see Figure 11C), or a surface emitter (see
- Figure I ID As shown in Figure I ID, the device will be a surface emitter if one electrode 110 is transparent.
- the thickness, t, of the isotope superlattice 86 should be adequate to allow vibrational wave coupling.
- t > > l/ ⁇ p , where ⁇ p is the coupling coefficient (see above).
- ⁇ M the modulation of the atomic mass
- M the average atomic mass.
- ⁇ L m( ⁇ p /2).
- N > > (2/ ⁇ )(M/ ⁇ M)(l/m)
- ( ⁇ M/M) 0.06.
- the number of Si 28 /Si 30 superlattice periods should preferably be greater than approximately 10, which corresponds to greater than approximately 50 atomic layers.
- Such an Si 28 /Si 30 superlattice is greater than approximately 100 A thick.
- Such light-emitting devices incorporating a phonon resonator of the present invention include light-emitting diodes and diode lasers (both Fabry-Perot and distributed feedback; see below).
- Light emitting devices of the present invention can be utilized alone, incorporated into other devices, or, for example assembled into an array used as a display.
- the present invention therefore encompasses a wide array of light emitting devices and/or systems, including any device or system in which at least one component incorporates a phonon resonator of the present invention.
- a light-emitting diode (LED) incorporating a phonon resonator of the present invention can be produced by equipping a generic light-emitting device such as that described in Example 1 above with a p-n junction, as is known in the art, for efficient injection of electrons and holes.
- Figure 12 depicts a simple embodiment of such an LED.
- an LED according to a preferred embodiment of the present invention constitutes a diode having an isotope superlattice 86 at the p-n junction.
- An n-type electrode layer 84 of single crystal silicon is grown on a substrate.
- An isotope superlattice 86 is then preferably grown on n-type layer 84.
- the isotope superlattice may contain, for example, ten alternating isotopically enriched layers, for example of Si 28 and Si 30 .
- a p-type electrode layer 82 comprising single crystal silicon is then formed on isotope superlattice 86.
- doping can, in principle, be accomplished either by ion implantation or by epitaxial growth.
- the n-type 84 and p-type 82 layers may be doped regions of the isotope superlattice 86, or may alternately be constructed from different materials (e.g. bulk silicon). Where the layers are doped regions, doping may be accomplished by any method available in the art, including, for example, diffusion, incorporation during growth, ion implantation, or neutron transmutation doping (see, for example, Haller Semicond. Sci. Tech. 5:319, 1990, incorporated herein by reference).
- the isotope superlattice is as thick as the depletion layer that would otherwise be formed between the p-type layer 82 and n-type layer 84.
- Electrons and holes can be injected into isotope superlattice layer 86 by applying a positive voltage to p-type layer 82 relative to the voltage applied to n-type region 84, thereby forward biasing the semiconductor laser diode. Photons 63 may then be emitted from the LED as shown in Figure 12, which depicts a surface-emitting device.
- the main technical requirement for overall efficiency in an LED such as that depicted in Figure 12 is a high radiative quantum efficiency (the average number of photons emitted per electron-hole pair injected).
- high radiative quantum efficiency is achieved by providing a structure in which electrons and holes are confined in the same region. As is known in the art, this can be achieved by a heterojunction.
- Figure 13 presents a depiction of an LED of the present invention utilizing a heterojunction.
- p and n layers 82 and 84 are substituted with p and n layers 92 and 94, respectively, that have a larger bandgap than that of the material in the isotope superlattice 86.
- layers of SiGeC alloy can be utilized with a silicon isotope superlattice. Electrons and holes are confined within the isotope superlattice.
- Figure 14 provides another embodiment of an LED of the present invention. Specifically, Figure 14 presents an edge-emitting LED that includes a dielectric waveguide 95 to provide optical as well as carrier confinement.
- a substrate 114 and a cover 112 each having refractive indexes, n 5 and n c respectively that are less than the refractive index, n f , of the phonon resonator 100, are positioned on opposite sides of the phonon resonator 100.
- the phonon resonator 100 comprises an isotope superlattice, preferably of silicon.
- the cover 112 and substrate 114 that have both a lower refractive index and a higher band gap than does the phonon resonator 100, so that the resultant LED has both a waveguide and a heterojunction.
- a phonon resonator of the present invention may be employed in a laser diode.
- a laser requires feedback. Feedback is accomplished by reflection, distributed feedback, or a combination of the two.
- Figure 15A depicts a cleaved facet reflection laser, also known as a Fabry- Perot laser, of the present invention.
- the cleaved facet reflection laser depicted in Figure 15A constitutes a diode having a phonon resonator 100, such as an isotope superlattice, at the p-n junction (see above for description).
- the laser further includes two facet reflectors 210, 220 disposed on opposing ends of the phonon resonator 100 that functions as a waveguide 95.
- a dielectric waveguide is not an essential component of a laser of the present invention.
- a device can be constructed with a region of very high gain that acts to provide a self- guiding optical wave.
- Figure 15B presents a distributed feedback laser of the present invention.
- the phonon resonator 100 functions as both a phonon resonator and a waveguide with substantially periodic optical characteristics (e.g. absorption or refractive index) such that the periodically varying waveguide supplies a Bragg resonance between forward and backward travelling waves.
- periodic optical characteristics e.g. absorption or refractive index
- Such periodically-varying optical properties are achieved by the corrugation 97 of one or more waveguide layers.
- the periodically-varying optical properties may be achieved by providing a phonon resonator 100 comprising a multitude of adjacent phonon resonators, 100A, 100B, etc. (see Figure 15C) spaced so that a Bragg resonance between forward and backward travelling waves is provided.
- a phonon resonator of the present invention may also be incorporated into a vertical cavity surface emitting laser (VECSEL).
- VECSEL vertical cavity surface emitting laser
- a VECSEL of the present invention comprises a top reflector 122 and a bottom reflector 124 positioned around a phonon resonator 100 as a p-n junction (see above). Electrodes 110 and 120 are positioned across the p-n junction and serve to inject current into the phonon resonator 100, thereby creating optical gain.
- the bottom reflector reflects approximately 100% of incident radiation and comprises alternating layers of materials having different refractive indices, n, and n 2 . Each layer has a thickness equal to ⁇ /2, where ⁇ is the wavelength of the amplified radiation.
- the thickness, t 124 , of the bottom reflector 124 follows the relationship:
- the top reflector 122 is also constructed of alternating layers, having thickness, t 122 ⁇ /2, of materials having refractive indices n, and n 2 , and the thickness of the top layer is selected so that between approximately 90 % and 100% of incident radiation is reflected. That is:
- the top reflector 122 allows between approximately 0% and 10% of incident radiation to be emitted as photons 63.
- a phonon resonator of the present invention can be fashioned into an optical amplifier, for example, by incorporating the phonon resonator into a p-n junction and optical waveguide as described above (see Example 2).
- the p-n junction is then pumped with an injection current in such a way that the phonon resonator exhibits optical gain through stimulated emission of photons.
- An optical signal having a photon energy approximately equal to the band-to-band transition energy of the phonon resonator is then injected into the waveguide.
- the optical signal experiences amplification when it passes through the portion of the waveguide that incorporates the phonon resonator.
- optical and/or optoelectronic devices incorporating a phonon resonator of the present invention can be combined with one another and/or with other devices as components of an optical communication system.
- an optical communications system of the present invention utilizes a light source (i.e. light emitting device) and/or an optical detector that incorporates a phonon resonator of the present invention.
- the light source is modified so that information is encoded in the intensity, phase, or frequency of the light.
- the detector is designed to convert the information into electrical impulses suitable for further signal processing.
- a phonon resonator of the present invention is incorporated into a laser, an optical amplifier, a modulator, a switch, a deflector, and/or a scanner.
- optical communications can be useful for long distance communications, local area networks, optical data storage, and/or broadcast services such as cable television. Such systems are also useful for interconnections among and within circuit boards and integrated circuits.
- EXAMPLE 7 Self-sustained oscillator for phonons and photons
- a phonon resonator of the present invention can be constructed so that it satisfies known requirements for photon resonators (e.g. so that optical gain is greater than cavity loss; see, for example, Agrawal et al. Long Wavelength Semiconductor Lasers Van Nostrand Reinhold New York 1986; Bass (ed) Handbook of Optics. Volumes I and E, McGraw-Hill, New York, 1995, each of which is hereby incorporated by reference), and is therefore resonant for both phonons and photons.
- the phonon and photon populations are coupled and the structure functions as a self-sustained, coupled phonon/photon oscillator.
- a self- sustained, coupled phonon/photon oscillator can be produced in which the phonon and photon populations are coupled in such a way that the nonlinear dynamics lead to hysterisis, bistability, and switching in the vibrational and/or optical output.
- a laser is constructed as set forth in either Example 3 or Example 4, and the nonlinearity is supplied by the population in the laser.
- a phonon resonator of the present invention can also be incorporated into an optical photodetector or optical modulator.
- Figures 17 and 18 depict two different embodiments of a photodetector/ modulator of the present invention.
- a lightly doped phonon resonator 100 is constructed in a p-n junction.
- a transparent electrode 110 and an electrode 120 are positioned on opposite sides of the heterojunction so that incoming radiation passes through the transparent electrode 110, and through the p-type region 82, and is absorbed in the phonon resonator 100 so that an electron-hole pair is produced and a photocurrent is induced between electrodes 110 and 120.
- electrodes 111 and 121 form an interdigitated pattern on the surface of the phonon resonator, and the photodetector/modulator has a substantially horizontal geometry as compared with the embodiment depicted in Figure 17.
- the electrodes may either form ohmic contacts to neighboring p doped and n doped regions, or may form Schottky contacts to a uniformly doped phonon resonators.
- One advantage of this design is that it permits high speed switching or detection due to the close proximity of the electrodes, and therefore to the short transit time required to communicate between them.
- the present invention also relates to indirect bandgap materials having enhanced electrical properties. Specifically, the invention encompasses materials having enhanced conductivity, including superconductivity, due to the presence of bound electron pairs.
- the invention encompasses materials having enhanced conductivity, including superconductivity, due to the presence of bound electron pairs.
- a conduction band electron can absorb or emit a phonon.
- the interaction between an electron and a phonon "scatters" the electron from one energy/momentum state to another. Specifically, absorption of a phonon increases the energy of the electron by an amount, E p , equal to the energy of the phonon, and changes the momentum of the electron by an amount equal to the wavenumber of the phonon. Likewise, phonon emission decreases the energy of the electron, and also changes the electron momentum.
- g(k) will contain only narrow components near ⁇ _( ⁇ t/ ⁇ )e z , and the pair potential will have the form:
- V( Zi -z V Q cos[2 ⁇ (z, -zJ/AJ,
- V(z -Z j ) F 0 exp(- ⁇ k. - ⁇ lcos[2 ⁇ t ⁇ . - ⁇ )/ ⁇ J
- the pair potential is oscillatory, and damps with the electronic mean free path.
- V 0 is comparable in magnitude to the
- the strength of the Coulomb interaction between electrons having large wavevector mismatch is proportional to 1/q 2 , where q is the magnitude of the mismatch.
- the Coulomb interaction between electrons in opposite valleys of a degenerate conduction band will therefore be somewhat weaker than that observed between electrons in the same conduction band valley.
- the probability of intervalley bound-pair formation is much higher than is the probability of formation of bound electron pairs within a single conduction valley.
- Intervalley bound pairs will only form if the pair binding energy is greater than zero. We can carry out a variational calculation of the ground state of the pair, and show that a bound state between electrons can exist even in the presence of carrier-carrier scattering.
- the first term is the energy of the non-interacting pair, while the second term gives the binding energy.
- WJ2 represents the binding energy in the low temperature limit.
- Figure 24 shows the reduction in the binding energy with increasing
- Figure 25 shows the binding energy as a function of the scattering potential V 0 for a fixed mean free path of 100 nm.
- the present invention provides a material with enhanced electrical conductivity by providing a material with bound electron pairs, preferably by increasing the rate of intervalley scattering (either direct or interzone) in the material.
- the level of intervalley scattering in a given material depends on the availability of phonons having the appropriate momentum.
- the present invention therefore provides a phonon resonator in which the vibrational energy (i.e. the phonon density) at the momentum necessary to produce direct and/or interzone intervalley scattering is enhanced.
- a phonon resonator is produced by providing a structure of periodically varying density, where the period of the structure is selected to increase the density of phonons having a momentum value and a wavelength appropriate to produce intervalley scattering.
- crystalline silicon exhibits an indirect bandgap in which the conduction band minimum is six-fold degenerate along the (100) direction, and occurs at approximately eight-tenths of the distance to the edge of the Brillouin zone.
- the degenerate conduction band minima of a single conduction band are therefore separated by 1.6 ⁇ /a in silicon.
- the superlattice would have to have a period of:
- ⁇ L 2.5m atomic layers.
- Figure 8 shows that the conduction band minima of neighboring Brillouin zones are separated by only 0.4x/a in silicon.
- the superlattice would have to have a period of:
- ⁇ L 10m atomic layers.
- m l
- the lowest-order silicon isotope superlattice of the present invention that acts as a resonator for phonons capable of participating in interzone intervalley scattering has a period double that of the lowest-order silicon isotope superlattice of the invention that is a resonator for phonons capable of participating in indirect radiative transitions.
- lattices having periods that are integer multiples of the period of the lowest-order resonator are also resonant for the same phonons for which the lowest-order resonator is resonant, it is clear that it is possible to produce an isotope superlattice of the present invention that is resonant both for phonons capable of participating in interzone intervalley scattering and for phonons capable of participating in indirect radiative transitions.
- EXAMPLE 9 Low -resistance conductor
- a phonon resonator of the present invention can be incorporated into a low- resistance conductor.
- One embodiment of such a low-resistance conductor is depicted in Figure 27.
- two devices 230a, b are connected by means of a phonon resonator 100, that carries electrical signals between the devices 230a, b.
- doping may be accomplished by any method available in the art, including, for example, diffusion, incorporation during growth, ion implantation, or neutron transmutation doping (see, for example, Haller Semicond. Sci. Tech. 5:319, 1990, incorporated herein by reference).
- a planar transformer is formed when at least two conducting pathways are arranged with respect to one another, e.g. in a serpentine configuration, so that alternating current flow is provided.
- a phonon resonator of the present invention can be incorporated into one or more of the conducting pathways, to produce a planar transformer with enhanced electrical conductivity, and therefore enhanced magnetic properties.
- a phonon resonator of the present invention could also be incorporated into other devices whose magnetic properties stem from electrical conductivity.
- a phonon resonator of the present invention can be incorporated into a diode as depicted in Figure 28.
- the phonon resonator 100 is incorporated into a p-n junction to form a diode with enhanced electrical properties.
- Contacts 240a, and b are shown positioned on opposite sides of the junction.
- EXAMPLE 12 Bipolar Transistor Figure 29 depicts a npn bipolar transistor inco ⁇ orating a phonon resonator of the present invention.
- the base 250 of the transistor comprises a phonon resonator 100 that enhances conduction between the emitter 260 and the collector 270.
- Figure 30 depicts a n-type Junction Field Effect Transistor (JFET) inco ⁇ orating a phonon resonator of the present invention.
- the gate 310 comprises a phonon resonator 100 that enhances conduction between source 320 and drain 330.
- a phonon resonator could also be inco ⁇ orated into an n-channel Metal Oxide Semiconductor Field Effect Transistor (MOSFET) (see Figure 31).
- MOSFET Metal Oxide Semiconductor Field Effect Transistor
- Figure 32 depicts an integrated circuit utilizing a combination of the above- described components (eg. a low-resistance conductor, a diode, a bipolar transistor, a JFET, and/or a MOSFET) inco ⁇ orating a phonon resonator.
- a low-resistance conductor e.g. a low-resistance conductor, a diode, a bipolar transistor, a JFET, and/or a MOSFET
- Any useful combination of components may be utilized, and related components that do not inco ⁇ orate a phonon resonator may be used in combination with components that do utilize a phonon resonator for enhanced electrical conduction.
- Electron-phonon interactions can be thought of as a source by which nonequilibrium phonons are generated. Thus, electron-phonon interactions can provide the gain mechanism necessary to achieve the vibrational analog of laser action in a resonator. Once such a phonon resonator reaches threshold, the emitted energy becomes both coherent and highly directional. A phonon resonator operating above threshold can therefore provide accelerated heat transfer from the resonator to the substrate on which the resonator resides via the coherent, directional emission of vibrational energy to the substrate.
- vibrational anharmonicities combined with a phonon resonator would be expected to exhibit stochastic resonances.
- These resonances are both coherent and directional, providing accelerated heat transfer from (or through) an isotope superlattice.
- a phonon resonator of the present invention can be fabricated by any of a variety of methods. We describe here the preparation of an isotope superlattice phonon resonator. There are two aspects to any method of producing an isotope superlattice: i) providing separate, substantially pure isotopes; and ii) assembling the substantially pure isotopes in a layered structure of the invention. These two aspects can be performed separately or simultaneously.
- isotope separation includes, among others, gaseous diffusion, gas centrifuge, fractional distillation, aerodynamic separation, chemical exchange, electromagnetic separation, and laser dissociation ionization (see, for, example London Separation of Isotopes, London: George Newnes, Ltd. , 1961 ;
- float zone segregation may be utilized for purification of a semiconductor.
- Methods available for assembling isotopically pure materials into an isotope superlattice of the present invention include, for example, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), and chemical beam epitaxy (CBE) (see, for example, Sedwick et al J. Vac Sci. Technol. A 10(4), 1992, inco ⁇ orated herein by reference).
- Isotopically pure materials prepared by any available method, including those recited above, may be used in combination with standard CVD, MBE, or CBE technologies to produce an isotope superlattice of the present invention.
- an isotope superlattice of the present invention may be prepared by performing isotope separation and layer deposition simultaneously.
- the laser dissociation isotope separation technique is utilized in combination with a CVD process, (i.e. as a "laser-assisted CVD" process) in a single chamber, to produce an isotope superlattice of the present invention (see Example 18).
- Examples 15-18 provide specific descriptions of fractional distillation, chemical exchange, laser dissociation, and laser-assisted CVD techniques, respectively.
- Fractional distillation can be utilized, for example, in the preparation of bulk precursors for epitaxial or Czochralski growth.
- Laser-assisted CVD provides in situ isotope separation and layer growth.
- the method of fractional distillation provides, after processing, for one isotopic species to remain in the liquid phase while the other is drawn off in a vapor phase.
- a preferred method for the separation of silicon isotopes would be the fractional distillation of SiCl 4 , a material which is liquid at room temperature but which provides a comparatively high vapor pressure. Since SiCl 4 is a standard precursor for production of both silane and elemental silicon, there is very little waste in this process.
- EXAMPLE 17 Laser dissociation and isotope-selective heating. Laser dissociation and isotope-selective heating is the preferred method for in situ separation and growth of isotope-pure layers.
- the laser dissociation technique of isotope separation relies on the fact that many molecules exhibit vibrational transitions in the near- to mid- infrared range.
- Bombarding molecules with radiation tuned to their vibrational transitions dissociates the molecules. Because the vibrational transitions of molecules are dependent on the masses of the atoms, molecules containing different isotopes of a given atom exhibit different transition energies. Thus, molecules containing different isotopes of a given atom are dissociated by bombardment with radiation of different frequencies.
- a variety of laser sources are available with access to the near- to mid- infrared region, that could be used to dissociate molecules having vibrational transitions in that region. For example, transitions in the 9-10 ⁇ m range are accessible using a CO 2 laser; various solid state lasers can access the near- infrared; and optical parametric oscillator technology can be utilized to achieve wide tunability.
- a mixture of molecules including the different isotopes is bombarded with radiation (i.e. from a laser) tuned to the vibrational transition frequency of a first molecule including a first isotope.
- the first molecule therefore becomes excited and can be separated from other molecules in the mixture by virtue of its higher temperature, or its increased sensitivity to photodissociation (see below).
- the radiation frequency can be adjusted by, for example, tuning the laser to a new frequency or providing an alternate laser source, so that the radiation frequency is tuned to the vibrational transition frequency of a second molecule, including a second isotope, and that second molecule can be isolated. The procedure is repeated until all desired isotopes are isolated.
- a silicon isotope superlattice of the present invention may be produced by exposing silane (SiH 4 ) gas to infrared radiation in a chamber such as that depicted in Figure 21.
- a wafer 300 is held in the chamber at a temperature below that required for spontaneous decomposition of silane.
- the wafer 300 may be positioned on a heater 350.
- a first laser 310 is tuned to the vibrational transition frequency of the first desired silicon isotope (e.g. Si 28 ). The laser excitation provides a large temperature differential between the desired isotope and the other isotopes, resulting in deposition of only the desired isotope on the wafer 300.
- the first laser 310 can be used to excite only the first desired silicon isotope, and a second laser 320 can provide a high energy photon to photoionize the excited silane molecules (i.e. those silane molecules containing the desired silicon isotope) , producing ions that have high reactivity with the surface of the wafer 300.
- the first laser 310 is adjusted and tuned to the vibrational transition frequency of the second desired silicon isotope (e.g. Si 30 ).
- the appropriate number of atomic layers of the second silicon isotope are then laid down.
- the process is reiterated until the desired isotope superlattice structure is produced.
- calibration of layer thickness can be carried out through a SIMS analysis.
- Standard in situ monitoring e.g. RHEED
- RHEED Standard in situ monitoring
- the disparity can be corrected, for example, by adjusting the laser power (e.g. lowering the laser power for depositing the majority isotope layers).
- the temperature in the chamber should be high enough to maintain the surface mobility of deposited silicon atoms, in order to assure epitaxial growth. It is also preferred that the isotope superlattice be grown in the direction of the lowest conduction band minimum. For silicon, this corresponds to the
- the isotope purity of an isotope superlattice of the present invention can be tested using any available method such as, for example, secondary ion mass spectroscopy or Raman scattering.
- important requirements for production of an isotopically pure superlattice of the present invention include the requirement that the wafer 300 be atomically clean, that the switching of laser frequencies does not lead to deposition of "mixed" isotopic layers, and that the chamber provide a substantially collision-free environment.
- the wafer 300 can be cleaned using standard methods and oxide removal should be performed.
- one particular embodiment of the method of the present invention provides a plurality of wafers 300 assembled onto a rotating carousel whose rotation is timed such that only pure isotope layers are deposited on wafers (i.e. so that mixed populations are produced during the times that gaps, instead of wafers, are exposed to the silane stream).
- a substantially collision-free environment is ensured in the method of the present invention, as depicted in Figure 21, by having the first 310 and second 320 lasers intersect at a point close to the surface of the wafer 300.
- the infrared windows 330 and 340, through which the first and second laser beams are directed be made of a material that will not be coated with silicon following the excitation.
- a phonon resonator may be inco ⁇ orated into any of a variety of other optical or electrical devices, as would readily be appreciated by one of ordinary skill in the art.
- a phonon resonator may be inco ⁇ orated into a superconducting quantum interference device (SQUID), a Josephson junction, a high frequency transistor, or a microwave detector, in order to enhance the electrical and/or thermal properties of those devices.
- SQUID superconducting quantum interference device
- Josephson junction a Josephson junction
- high frequency transistor or a microwave detector
- the present specification describes a structure of periodically varying density (e.g. an isotope superlattice).
- the density of the preferred structure described above is varied by providing alternating layers of material of different mass density.
- Another way to periodically vary the mass density of a structure is to introduce a standing wave into the structure.
- phonons normally only propagate 100-1000 A without scattering, a sound wave having a wavelength of much less than 1000 A would be required to establish the necessary standing wave. Such sound waves cannot practically be generated.
- the preferred embodiment of the structure of periodically varying density of the present invention is a structure having layers of material of different density, most preferably an isotope superlattice as described herein.
- a structure of periodically varying density such as that described herein could be designed to suppress, rather than to enhance, phonons of particular wavevectors.
- a structure of the present invention can be assembled as described herein, having been designed not to be resonant for, and therefore to suppress, phonons at the energies required to ionize an electron. Such a structure would improved the performance of the quantum well or wire.
- an isotope superlattice of the present invention could be constructed from isotopically enriched layers of two or more different elements or compounds, provided that the overall structure is designed to be resonant for phonons of appropriate wavevector to participate in phonon-electron interactions.
- a structure could be assembled comprising two atomic layers of a carbon isotope alternating with three atomic layers of a silicon isotope. Such a structure would exhibit a large (greater than approximately 2.5 eV) indirect bandgap, and would be suitable for use in, for example, a light emitting device such as those described herein.
- silane SiH ⁇ as a starting material to produce a silicon isotope superlattice of the invention by laser-assisted isotope separation.
- Other starting materials could also be used such as, for example, SiH 2 Cl 2 , SiF 4 , or any other member of the halide-silane family of gases, although heavier molecules such as dichlorosilane (SiH 2 Cl 2 ) have complicated vibrational spectra, which makes identification of a vibrational abso ⁇ tion frequency that is clearly associated with a single silicon isotope is more difficult.
- silane is the preferred source gas for laser-assisted isotope separation.
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT96908469T ATE252276T1 (en) | 1995-02-17 | 1996-02-14 | PHONON RESONATOR |
EP96908469A EP0838093B1 (en) | 1995-02-17 | 1996-02-14 | Phonon resonator |
JP52513796A JP3974654B2 (en) | 1995-02-17 | 1996-02-14 | Phonon resonance device and manufacturing method thereof |
AU51700/96A AU5170096A (en) | 1995-02-17 | 1996-02-14 | Phonon resonator and method for its production |
DE69630387T DE69630387T2 (en) | 1995-02-17 | 1996-02-14 | phonon |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/393,380 | 1995-02-17 | ||
US08/393,380 US5917195A (en) | 1995-02-17 | 1995-02-17 | Phonon resonator and method for its production |
Publications (2)
Publication Number | Publication Date |
---|---|
WO1996025767A2 true WO1996025767A2 (en) | 1996-08-22 |
WO1996025767A3 WO1996025767A3 (en) | 1996-09-26 |
Family
ID=23554464
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1996/002052 WO1996025767A2 (en) | 1995-02-17 | 1996-02-14 | Phonon resonator and method for its production |
Country Status (9)
Country | Link |
---|---|
US (1) | US5917195A (en) |
EP (1) | EP0838093B1 (en) |
JP (1) | JP3974654B2 (en) |
AT (1) | ATE252276T1 (en) |
AU (1) | AU5170096A (en) |
CA (1) | CA2213210A1 (en) |
DE (1) | DE69630387T2 (en) |
ES (1) | ES2208732T3 (en) |
WO (1) | WO1996025767A2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0895292A1 (en) * | 1997-07-29 | 1999-02-03 | Hitachi Europe Limited | Electroluminescent device |
WO2000048275A1 (en) * | 1999-02-10 | 2000-08-17 | Commissariat A L'energie Atomique | Silicon light-emitting device and method for the production thereof |
EP1107044A1 (en) * | 1999-11-30 | 2001-06-13 | Hitachi Europe Limited | Photonic device |
US6829269B2 (en) | 2002-05-21 | 2004-12-07 | University Of Massachusetts | Systems and methods using phonon mediated intersubband laser |
Families Citing this family (55)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6146601A (en) * | 1999-10-28 | 2000-11-14 | Eagle-Picher Industries, Inc. | Enrichment of silicon or germanium isotopes |
US7223914B2 (en) | 1999-05-04 | 2007-05-29 | Neokismet Llc | Pulsed electron jump generator |
US6649823B2 (en) * | 1999-05-04 | 2003-11-18 | Neokismet, L.L.C. | Gas specie electron-jump chemical energy converter |
US6678305B1 (en) * | 1999-05-04 | 2004-01-13 | Noekismet, L.L.C. | Surface catalyst infra red laser |
US7371962B2 (en) | 1999-05-04 | 2008-05-13 | Neokismet, Llc | Diode energy converter for chemical kinetic electron energy transfer |
JP3422482B2 (en) * | 2000-02-17 | 2003-06-30 | 日本電気株式会社 | Single photon generator |
US6734453B2 (en) | 2000-08-08 | 2004-05-11 | Translucent Photonics, Inc. | Devices with optical gain in silicon |
AU2000264174A1 (en) * | 2000-08-15 | 2002-02-25 | Silex Systems Limited | A semiconductor isotope superlattice |
AUPR083300A0 (en) * | 2000-10-17 | 2000-11-09 | Silex Systems Limited | An isotope structure formed in an indriect band gap semiconductor material |
WO2002058219A2 (en) * | 2001-01-17 | 2002-07-25 | Neokismet, L.L.C. | Electron-jump chemical energy converter |
US7122735B2 (en) * | 2001-06-29 | 2006-10-17 | Neokismet, L.L.C. | Quantum well energizing method and apparatus |
US7119400B2 (en) * | 2001-07-05 | 2006-10-10 | Isonics Corporation | Isotopically pure silicon-on-insulator wafers and method of making same |
US20040171226A1 (en) * | 2001-07-05 | 2004-09-02 | Burden Stephen J. | Isotopically pure silicon-on-insulator wafers and method of making same |
US6867459B2 (en) * | 2001-07-05 | 2005-03-15 | Isonics Corporation | Isotopically pure silicon-on-insulator wafers and method of making same |
US6653658B2 (en) * | 2001-07-05 | 2003-11-25 | Isonics Corporation | Semiconductor wafers with integrated heat spreading layer |
WO2003023824A2 (en) * | 2001-09-10 | 2003-03-20 | California Institute Of Technology | Modulator based on tunable resonant cavity |
US6834152B2 (en) * | 2001-09-10 | 2004-12-21 | California Institute Of Technology | Strip loaded waveguide with low-index transition layer |
JP2003292398A (en) * | 2002-03-29 | 2003-10-15 | Canon Inc | Method for producing single crystal silicon wafer |
DE60220803T2 (en) * | 2002-11-29 | 2008-03-06 | MAX-PLANCK-Gesellschaft zur Förderung der Wissenschaften e.V. | Semiconductor structure for infrared and manufacturing process |
WO2004051761A2 (en) * | 2002-12-02 | 2004-06-17 | Institute For Scientific Research, Inc. | Isotopically enriched piezoelectric devices and method for making the same |
US7209618B2 (en) * | 2003-03-25 | 2007-04-24 | Hewlett-Packard Development Company, L.P. | Scanner transparent media adapter using fiber optic face plate |
JP2005083862A (en) * | 2003-09-08 | 2005-03-31 | Canon Inc | Optical thin-film and mirror using it |
US7315679B2 (en) * | 2004-06-07 | 2008-01-01 | California Institute Of Technology | Segmented waveguide structures |
US7176112B2 (en) * | 2004-09-21 | 2007-02-13 | Atmel Corporation | Non-thermal annealing with electromagnetic radiation in the terahertz range of doped semiconductor material |
JP4550613B2 (en) * | 2005-02-21 | 2010-09-22 | 古河電気工業株式会社 | Anisotropic heat conduction material |
US7826688B1 (en) | 2005-10-21 | 2010-11-02 | Luxtera, Inc. | Enhancing the sensitivity of resonant optical modulating and switching devices |
US7619238B2 (en) * | 2006-02-04 | 2009-11-17 | Sensor Electronic Technology, Inc. | Heterostructure including light generating structure contained in potential well |
JP2007238862A (en) * | 2006-03-10 | 2007-09-20 | Denso Corp | Heat transport medium |
JP5004072B2 (en) * | 2006-05-17 | 2012-08-22 | 学校法人慶應義塾 | Ion irradiation effect evaluation method, process simulator and device simulator |
JP2008063411A (en) * | 2006-09-06 | 2008-03-21 | Denso Corp | Heat-transporting fluid, heat-transporting structure and method for transporting heat |
US20100247884A1 (en) | 2007-10-03 | 2010-09-30 | National Institute Of Advanced Industrial Science | Stacked body of isotope diamond |
US8450704B2 (en) * | 2009-12-04 | 2013-05-28 | Massachusetts Institute Of Technology | Phonon-enhanced crystal growth and lattice healing |
US9806226B2 (en) | 2010-06-18 | 2017-10-31 | Sensor Electronic Technology, Inc. | Deep ultraviolet light emitting diode |
US8927959B2 (en) | 2010-06-18 | 2015-01-06 | Sensor Electronic Technology, Inc. | Deep ultraviolet light emitting diode |
US8907322B2 (en) | 2010-06-18 | 2014-12-09 | Sensor Electronic Technology, Inc. | Deep ultraviolet light emitting diode |
US8739859B2 (en) | 2010-10-04 | 2014-06-03 | Toyota Motor Engineering & Manufacturing North America, Inc. | Reversible thermal rectifiers, temperature control systems and vehicles incorporating the same |
KR101265178B1 (en) | 2011-12-23 | 2013-05-15 | 서울대학교산학협력단 | Electroluminescence device using indirect bandgab semiconductor |
WO2013101261A1 (en) | 2011-12-30 | 2013-07-04 | Bell James Dalton | Isotopically altered optical fiber |
US9059388B2 (en) * | 2012-03-21 | 2015-06-16 | University Of Maryland College Park | Phoniton systems, devices, and methods |
US9817153B2 (en) | 2012-05-22 | 2017-11-14 | Nxt Energy Solutions, Inc. | Gravity transducer system and method including a junction with a first metal and a second metal |
US9437892B2 (en) | 2012-07-26 | 2016-09-06 | Quswami, Inc. | System and method for converting chemical energy into electrical energy using nano-engineered porous network materials |
JP5677385B2 (en) | 2012-08-24 | 2015-02-25 | 株式会社東芝 | Stimulated phonon emission device |
US9291297B2 (en) | 2012-12-19 | 2016-03-22 | Elwha Llc | Multi-layer phononic crystal thermal insulators |
US8847204B2 (en) | 2013-02-26 | 2014-09-30 | Seoul National University R&Db Foundation | Germanium electroluminescence device and fabrication method of the same |
US9268092B1 (en) * | 2013-03-14 | 2016-02-23 | Sandia Corporation | Guided wave opto-acoustic device |
US8975617B2 (en) * | 2013-06-03 | 2015-03-10 | Dan Berco | Quantum interference device |
US10304535B2 (en) * | 2015-03-30 | 2019-05-28 | Yeda Research And Development Co. Ltd. | All-optical single-atom photon router controlled by a single photon |
JP2017092075A (en) * | 2015-11-02 | 2017-05-25 | 株式会社ソディック | Light emitting element |
US10097281B1 (en) | 2015-11-18 | 2018-10-09 | Hypres, Inc. | System and method for cryogenic optoelectronic data link |
KR102181323B1 (en) * | 2016-04-06 | 2020-11-23 | 한국전자통신연구원 | Laser device and methods for manufacturing the same |
JP6278423B2 (en) * | 2016-06-30 | 2018-02-14 | 株式会社ソディック | Light emitting element |
US11810784B2 (en) | 2021-04-21 | 2023-11-07 | Atomera Incorporated | Method for making semiconductor device including a superlattice and enriched silicon 28 epitaxial layer |
TWI806553B (en) * | 2021-04-21 | 2023-06-21 | 美商安托梅拉公司 | Semiconductor device including a superlattice and enriched silicon 28 epitaxial layer and associated methods |
US11923418B2 (en) | 2021-04-21 | 2024-03-05 | Atomera Incorporated | Semiconductor device including a superlattice and enriched silicon 28 epitaxial layer |
CN117616434A (en) | 2021-04-27 | 2024-02-27 | 量子源实验室有限公司 | Quantum computation |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56164588A (en) * | 1980-05-23 | 1981-12-17 | Nippon Telegr & Teleph Corp <Ntt> | Semiconductor light amplifier |
US4349796A (en) * | 1980-12-15 | 1982-09-14 | Bell Telephone Laboratories, Incorporated | Devices incorporating phonon filters |
US4469977A (en) * | 1982-10-19 | 1984-09-04 | The United States Of America As Represented By The Secretary Of The Navy | Superlattice ultrasonic wave generator |
JPS63115385A (en) * | 1986-11-04 | 1988-05-19 | Sony Corp | Semiconductor device |
JPS6415687A (en) * | 1987-07-09 | 1989-01-19 | Nippon Steel Corp | Radiation detecting element |
US5061970A (en) * | 1990-06-04 | 1991-10-29 | Motorola, Inc. | Energy band leveling modulation doped quantum well |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5593256A (en) * | 1979-01-10 | 1980-07-15 | Sony Corp | Semiconductor device |
FR2485810A1 (en) * | 1980-06-24 | 1981-12-31 | Thomson Csf | PROCESS FOR PRODUCING A LAYER CONTAINING SILICON AND PHOTOELECTRIC CONVERSION DEVICE USING THE SAME |
FR2511887A1 (en) * | 1981-08-28 | 1983-03-04 | Commissariat Energie Atomique | ISOTOPIC SEPARATION PROCESS BY TRANSFER OF VIBRATIONAL ENERGY |
US4591889A (en) * | 1984-09-14 | 1986-05-27 | At&T Bell Laboratories | Superlattice geometry and devices |
US4785340A (en) * | 1985-03-29 | 1988-11-15 | Director-General Of The Agency Of Industrial Science And Technology | Semiconductor device having doping multilayer structure |
JPS61274322A (en) * | 1985-05-29 | 1986-12-04 | Mitsubishi Electric Corp | Manufacture of semiconductor device |
JPS63269573A (en) * | 1987-04-27 | 1988-11-07 | Nippon Telegr & Teleph Corp <Ntt> | Semiconductor device having heterojunction |
WO1989006050A1 (en) * | 1987-12-23 | 1989-06-29 | British Telecommunications Public Limited Company | Semiconductor heterostructures |
US5012302A (en) * | 1990-03-30 | 1991-04-30 | Motorola, Inc. | Enhanced conductivity quantum well having resonant charge coupling |
US5144409A (en) * | 1990-09-05 | 1992-09-01 | Yale University | Isotopically enriched semiconductor devices |
JPH0541355A (en) * | 1991-08-05 | 1993-02-19 | Fujitsu Ltd | Modulation semiconductor material and semiconductor device using same |
US5436468A (en) * | 1992-03-17 | 1995-07-25 | Fujitsu Limited | Ordered mixed crystal semiconductor superlattice device |
-
1995
- 1995-02-17 US US08/393,380 patent/US5917195A/en not_active Expired - Fee Related
-
1996
- 1996-02-14 ES ES96908469T patent/ES2208732T3/en not_active Expired - Lifetime
- 1996-02-14 AT AT96908469T patent/ATE252276T1/en not_active IP Right Cessation
- 1996-02-14 WO PCT/US1996/002052 patent/WO1996025767A2/en active IP Right Grant
- 1996-02-14 CA CA002213210A patent/CA2213210A1/en not_active Abandoned
- 1996-02-14 EP EP96908469A patent/EP0838093B1/en not_active Expired - Lifetime
- 1996-02-14 DE DE69630387T patent/DE69630387T2/en not_active Expired - Fee Related
- 1996-02-14 JP JP52513796A patent/JP3974654B2/en not_active Expired - Fee Related
- 1996-02-14 AU AU51700/96A patent/AU5170096A/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56164588A (en) * | 1980-05-23 | 1981-12-17 | Nippon Telegr & Teleph Corp <Ntt> | Semiconductor light amplifier |
US4349796A (en) * | 1980-12-15 | 1982-09-14 | Bell Telephone Laboratories, Incorporated | Devices incorporating phonon filters |
US4469977A (en) * | 1982-10-19 | 1984-09-04 | The United States Of America As Represented By The Secretary Of The Navy | Superlattice ultrasonic wave generator |
JPS63115385A (en) * | 1986-11-04 | 1988-05-19 | Sony Corp | Semiconductor device |
JPS6415687A (en) * | 1987-07-09 | 1989-01-19 | Nippon Steel Corp | Radiation detecting element |
US5061970A (en) * | 1990-06-04 | 1991-10-29 | Motorola, Inc. | Energy band leveling modulation doped quantum well |
Non-Patent Citations (7)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 006, no. 052 (E-100), 7 April 1982 & JP,A,56 164588 (NIPPON TELEGR & TELEPH CORP), 17 December 1981, * |
PATENT ABSTRACTS OF JAPAN vol. 012, no. 362 (E-663), 28 September 1988 & JP,A,63 115385 (SONY CORP), 19 May 1988, * |
PATENT ABSTRACTS OF JAPAN vol. 013, no. 188 (P-866), 8 May 1989 & JP,A,01 015687 (NIPPON STEEL CORP), 19 January 1989, * |
PHYSICAL REVIEW B (CONDENSED MATTER), 1 JAN. 1992, USA, vol. 45, no. 2, ISSN 0163-1829, pages 734-741, XP002007652 MIZUNO S ET AL: "Theory of acoustic-phonon transmission in finite-size superlattice systems" * |
PHYSICAL REVIEW LETTERS, 7 MARCH 1994, USA, vol. 72, no. 10, ISSN 0031-9007, pages 1565-1568, XP002007651 SPITZER J ET AL: "Raman scattering by optical phonons in isotopic /sup 70/(Ge)/sub n//sup 74/(Ge)/sub n/ superlattices" * |
See also references of EP0838093A2 * |
SUPERLATTICES AND MICROSTRUCTURES, 1993, UK, vol. 14, no. 1, ISSN 0749-6036, pages 123-128, XP000450506 PERERA A G U ET AL: "Far infrared detection with a Si p-i interface and multilayer structures" * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0895292A1 (en) * | 1997-07-29 | 1999-02-03 | Hitachi Europe Limited | Electroluminescent device |
WO2000048275A1 (en) * | 1999-02-10 | 2000-08-17 | Commissariat A L'energie Atomique | Silicon light-emitting device and method for the production thereof |
US6570187B1 (en) | 1999-02-10 | 2003-05-27 | Commissariat a l′Energie Atomique | Silicon light-emitting device and method for the production thereof |
EP1107044A1 (en) * | 1999-11-30 | 2001-06-13 | Hitachi Europe Limited | Photonic device |
US6483100B1 (en) | 1999-11-30 | 2002-11-19 | Hitachi, Ltd. | Photonic device |
US6829269B2 (en) | 2002-05-21 | 2004-12-07 | University Of Massachusetts | Systems and methods using phonon mediated intersubband laser |
Also Published As
Publication number | Publication date |
---|---|
EP0838093A2 (en) | 1998-04-29 |
ATE252276T1 (en) | 2003-11-15 |
AU5170096A (en) | 1996-09-04 |
CA2213210A1 (en) | 1996-08-22 |
JP3974654B2 (en) | 2007-09-12 |
EP0838093B1 (en) | 2003-10-15 |
JPH11500580A (en) | 1999-01-12 |
WO1996025767A3 (en) | 1996-09-26 |
ES2208732T3 (en) | 2004-06-16 |
DE69630387D1 (en) | 2003-11-20 |
US5917195A (en) | 1999-06-29 |
DE69630387T2 (en) | 2004-07-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5917195A (en) | Phonon resonator and method for its production | |
Ossicini et al. | Light emitting silicon for microphotonics | |
Sun et al. | Design of an electrically pumped SiGeSn/GeSn/SiGeSn double-heterostructure midinfrared laser | |
US6151347A (en) | Laser diode and method of fabrication thereof | |
RU2396655C1 (en) | Tunnel-coupled semi-conducting heterostructure | |
Reboud et al. | Lasing in Group-IV materials | |
Dingle et al. | Quantum effects in heterostructure lasers | |
Harrison et al. | Population-inversion and gain estimates for a semiconductor TASER | |
Kolbas et al. | Laser properties and carrier collection in ultrathin quantum-well heterostructures | |
Lee et al. | Bandgap tuning of In0. 53Ga0. 47As/InP multiquantum well structure by impurity free vacancy diffusion using In0. 53Ga0. 47As cap layer and SiO2 dielectric capping | |
JPH0268516A (en) | Optical communication modulator | |
CN108493770B (en) | Simulation method for photon pair source associated with electric pumping Bragg reflection waveguide | |
JP2932059B2 (en) | Solar cell | |
Kumabe et al. | High temperature single mode cw operation with a TJS laser using a semi-insulating GaAs substrate | |
Wang | High-performance III-V quantum-dot lasers monolithically grown on Si and Ge substrates for Si photonics | |
JP2001135893A (en) | Optical semiconductor device and photoelectron integrated circuit device | |
Stange et al. | High Sn‐Content GeSn Light Emitters for Silicon Photonics | |
Ralston et al. | Novel molecular‐beam epitaxially grown GaAs/AlGaAs quantum well structures for infrared detection and integrated optics at 3–5 and 8–12 μm | |
Moatlhodi | Vertical cavity surface emiting laser for optical communication systems | |
Larkin et al. | Effect of a parallel magnetic field on the photocurrent in GaAs/AlAs p− i− n-structures | |
Li | device realizatiOns | |
Lai et al. | Observation of intersubband absorption in the forbidden polarisation for a stepped double barrier quantum well | |
Slivken | Quantum cascade lasers grown by gas-source molecular beam epitaxy | |
Seeger et al. | Light Generation by Semiconductors | |
Herbert Li | Diffused Quantum Well Structures: Advances in Materials and Device Realizations |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): AL AM AT AU AZ BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IS JP KE KG KP KR KZ LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TR TT UA UG UZ VN AZ BY KG KZ RU TJ TM |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): KE LS MW SD SZ UG AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN |
|
AK | Designated states |
Kind code of ref document: A3 Designated state(s): AL AM AT AU AZ BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IS JP KE KG KP KR KZ LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TR TT UA UG UZ VN AZ BY KG KZ RU TJ TM |
|
AL | Designated countries for regional patents |
Kind code of ref document: A3 Designated state(s): KE LS MW SD SZ UG AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
ENP | Entry into the national phase |
Ref document number: 2213210 Country of ref document: CA Ref country code: CA Ref document number: 2213210 Kind code of ref document: A Format of ref document f/p: F |
|
ENP | Entry into the national phase |
Ref country code: JP Ref document number: 1996 525137 Kind code of ref document: A Format of ref document f/p: F |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1996908469 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWP | Wipo information: published in national office |
Ref document number: 1996908469 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 1996908469 Country of ref document: EP |