USH1637H - Laser-assisted fabrication of bipolar transistors in silicon-on-sapphire (SOS) - Google Patents
Laser-assisted fabrication of bipolar transistors in silicon-on-sapphire (SOS) Download PDFInfo
- Publication number
- USH1637H USH1637H US07/762,538 US76253891A USH1637H US H1637 H USH1637 H US H1637H US 76253891 A US76253891 A US 76253891A US H1637 H USH1637 H US H1637H
- Authority
- US
- United States
- Prior art keywords
- silicon
- sapphire wafer
- dopant
- laser
- wafer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 229910052594 sapphire Inorganic materials 0.000 title claims abstract description 63
- 239000010980 sapphire Substances 0.000 title claims abstract description 63
- 238000004519 manufacturing process Methods 0.000 title abstract description 25
- 239000002019 doping agent Substances 0.000 claims abstract description 65
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 60
- 239000010703 silicon Substances 0.000 claims abstract description 58
- 238000012545 processing Methods 0.000 claims abstract description 47
- 230000004913 activation Effects 0.000 claims abstract description 29
- 238000009792 diffusion process Methods 0.000 claims abstract description 27
- 239000000155 melt Substances 0.000 claims abstract description 15
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 14
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 11
- 230000008018 melting Effects 0.000 claims abstract description 9
- 238000002844 melting Methods 0.000 claims abstract description 9
- 238000002679 ablation Methods 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 claims description 97
- 238000011065 in-situ storage Methods 0.000 claims description 12
- 238000010348 incorporation Methods 0.000 claims description 10
- 230000002401 inhibitory effect Effects 0.000 claims 9
- 230000007547 defect Effects 0.000 abstract description 12
- 238000005286 illumination Methods 0.000 abstract description 7
- 230000000873 masking effect Effects 0.000 abstract description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 41
- 230000008569 process Effects 0.000 description 37
- 235000012431 wafers Nutrition 0.000 description 35
- 239000000463 material Substances 0.000 description 20
- 238000001994 activation Methods 0.000 description 17
- 238000005516 engineering process Methods 0.000 description 13
- 239000007789 gas Substances 0.000 description 10
- 239000004065 semiconductor Substances 0.000 description 10
- 239000007943 implant Substances 0.000 description 9
- 238000005224 laser annealing Methods 0.000 description 9
- 238000000137 annealing Methods 0.000 description 7
- 238000000151 deposition Methods 0.000 description 7
- 230000008021 deposition Effects 0.000 description 7
- 238000002955 isolation Methods 0.000 description 7
- 238000002310 reflectometry Methods 0.000 description 7
- 239000000758 substrate Substances 0.000 description 7
- 239000007787 solid Substances 0.000 description 6
- 230000003993 interaction Effects 0.000 description 5
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 238000005530 etching Methods 0.000 description 4
- 238000002513 implantation Methods 0.000 description 4
- 208000012868 Overgrowth Diseases 0.000 description 3
- 238000004380 ashing Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000010894 electron beam technology Methods 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 239000012212 insulator Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000000059 patterning Methods 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 238000012552 review Methods 0.000 description 3
- 238000000348 solid-phase epitaxy Methods 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- XYFCBTPGUUZFHI-UHFFFAOYSA-N Phosphine Chemical compound P XYFCBTPGUUZFHI-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- WTEOIRVLGSZEPR-UHFFFAOYSA-N boron trifluoride Chemical compound FB(F)F WTEOIRVLGSZEPR-UHFFFAOYSA-N 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000001312 dry etching Methods 0.000 description 2
- 238000000407 epitaxy Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000005468 ion implantation Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 229920002120 photoresistant polymer Polymers 0.000 description 2
- 238000001020 plasma etching Methods 0.000 description 2
- 238000004886 process control Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 238000001039 wet etching Methods 0.000 description 2
- RFCAUADVODFSLZ-UHFFFAOYSA-N 1-Chloro-1,1,2,2,2-pentafluoroethane Chemical compound FC(F)(F)C(F)(F)Cl RFCAUADVODFSLZ-UHFFFAOYSA-N 0.000 description 1
- 229910015900 BF3 Inorganic materials 0.000 description 1
- 239000004340 Chloropentafluoroethane Substances 0.000 description 1
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 229910007277 Si3 N4 Inorganic materials 0.000 description 1
- 229910000577 Silicon-germanium Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- LEVVHYCKPQWKOP-UHFFFAOYSA-N [Si].[Ge] Chemical compound [Si].[Ge] LEVVHYCKPQWKOP-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910021417 amorphous silicon Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- RBFQJDQYXXHULB-UHFFFAOYSA-N arsane Chemical compound [AsH3] RBFQJDQYXXHULB-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 235000019406 chloropentafluoroethane Nutrition 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000003913 materials processing Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229910000073 phosphorus hydride Inorganic materials 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 210000002381 plasma Anatomy 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000007725 thermal activation Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/26—Bombardment with radiation
- H01L21/263—Bombardment with radiation with high-energy radiation
- H01L21/265—Bombardment with radiation with high-energy radiation producing ion implantation
- H01L21/26506—Bombardment with radiation with high-energy radiation producing ion implantation in group IV semiconductors
- H01L21/26513—Bombardment with radiation with high-energy radiation producing ion implantation in group IV semiconductors of electrically active species
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/26—Bombardment with radiation
- H01L21/263—Bombardment with radiation with high-energy radiation
- H01L21/265—Bombardment with radiation with high-energy radiation producing ion implantation
- H01L21/2658—Bombardment with radiation with high-energy radiation producing ion implantation of a molecular ion, e.g. decaborane
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/26—Bombardment with radiation
- H01L21/263—Bombardment with radiation with high-energy radiation
- H01L21/268—Bombardment with radiation with high-energy radiation using electromagnetic radiation, e.g. laser radiation
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
- H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices
- H01L21/82—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices to produce devices, e.g. integrated circuits, each consisting of a plurality of components
- H01L21/84—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices to produce devices, e.g. integrated circuits, each consisting of a plurality of components the substrate being other than a semiconductor body, e.g. being an insulating body
- H01L21/86—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices to produce devices, e.g. integrated circuits, each consisting of a plurality of components the substrate being other than a semiconductor body, e.g. being an insulating body the insulating body being sapphire, e.g. silicon on sapphire structure, i.e. SOS
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66234—Bipolar junction transistors [BJT]
- H01L29/66265—Thin film bipolar transistors
Definitions
- VLSI Very Large Scale Integration
- S. J. Duey and G. W. Neudeck "A Novel Quasi-Dielectrically Isolated Bipolar Transistor Using Epitaxial Lateral Overgrowth", in J. Jopke, ed., Proceddings of the 1988 Bipolar Circuits & Technology Meeting, 1988, pp. 241-244.
- SOI silicon-on-insulator
- SOI technologies promise to offer increased device performance by reducing parasitic capacitance, interconnect delay, and increased radiation hardness.
- Many examples of SOI technologies are known, but with limited degrees of success and process maturity, for example, see the article by J. Jastrzebski, "Silicon on Insulators: Different Approaches: A Review", J. Crystal Growth, vol. 70, 1984, p. 253.
- SOI technology small islands of silicon which contain the individual device are fabricated on an insulating substrate, and then interconnected in the normal way. Likely to be attendant with these technologies is the difficulty, or inability to achieve "device quality" silicon on an insulating layer.
- Device quality is defined as silicon layers without crystallographic defects and/or impurities which prevent fabrication of functioning devices.
- One SOI technique employs the ion implantation of oxygen or nitrogen into bulk silicon forming a buried oxide (SiO 2 ) called the SIMOX process, as described by M. K. El-Ghor, S. J. Pennycook, F. Namavar, and N. H., Karam in "Formation of Low Dislocation Density Silicon-on-Insulator by a Single Implantation and Annealing", Appl. Phys. Lett., vol. 57, 1990, p. 156, or a buried nitride (Si 3 N 4 ) layer.
- ELO Epitaxial Lateral Overgrowth
- Zone Melt Recrystallization uses a moving filament to remelt silicon deposited on SiO 2 using patterned openings to the bulk Si below as a seed crystal for regrowth, note the article by G. A. Rozgonyi et al., "Structural and Electrical Properties of Epitaxial Si on Insulating Substrates", Appl. Phys. Lett., vol. 55, 1989, p. 586.
- SOS silicon-on-sapphire
- G. W. Cullen's The Preparation and Properties of Chemically Vapor Deposited Silicon on Sapphire and Spinel
- This latter reference achieved low gain functional transistors, but noted that small area devices must be fabricated because of the high density of crystal imperfections that cause emitter-collector shorts.
- Diffusion pipes are crystallographic defects which allow paths for dopant atoms to diffuse (or migrate) during high temperature anneals.
- the anneals are critical in the processing of semiconductor devices in that they allow the electrical activation of ion implanted dopant atoms. Therefore the diffusion of dopant from one junction into another (e.g. the emitter to the base) results in leaky or shorted devices. Therefore, research and development into high quality crystalline films on sapphire and novel processing techniques are of continuing interest for SOS device fabrication.
- Yamada et al. performed thermally-assisted pulse laser annealing of SOS, see M. Yamada et al., "Thermally-Assisted Pulsed-Laser Annealing of SOS", in J. F. Gibbons et al., eds, Laser and Electron-Beam Solid Interactions and Materials Processing, Mat. Res. Soc. Symp. Proc., vol. 1, 1981, p. 503.
- Raman spectroscopy they measured the residual strain in annealed SOS due to the lattice mismatch between Si and sapphire. They performed no examination of laser dopant activation.
- Alestig et al. performed continuous wave (cw) laser annealing of ion implanted oxidized silicon layers on sapphire, see the article by G. Alestig et al., "CW Laser Annealing of Ion Implanted Oxidized Silicon Layers on Sapphire", in J Narayan et al., eds., Laser-Solid Interactions and Transient Thermal Processing of Materials, Mat. Res. Soc. Symp. Proc., vol. 13, 1983, p. 517. They demonstrated activation of boron and phosphorous dopants by illumination from both the top and backside of the wafer. They reported visible damage was obtained when using power sufficient to melt the silicon. Similarly, Hess et al.
- the present invention is directed to providing a method for the fabrication of bipolar junction transistors by laser-assisted dopant activation in silicon-on-sapphire (SOS).
- SOS silicon-on-sapphire
- a patterned 100% aluminum mask is provided for an SOS wafer whose function is to reflect laser light from regions where melting of the silicon is undesirable (for example, in previously processed regions).
- the SOS wafer to be processed is then placed within an evacuated and inert atmosphere backfilled wafer carrier having a window transparent to the wavelength of the laser beam, to allow illumination of the masked wafer when the carrier is inserted into a processing chamber of a laser processing system including an in-situ reflectivity monitor to measure the melt duration of the silicon.
- the laser beam typically emitted from an excimer laser, is shaped, homogenized, and at least one pulse is directed onto the SOS wafer to be processed.
- the laser pulse energy and pulse duration are set to obtain the optimal fluence impinging on the wafer in order to achieve the desired melt duration and corresponding junction depth.
- an in-situ laser-assisted dopant incorporation process (referred to as GILD in the Background of the Invention, supra) where the patterned SOS wafer to be processed is placed within an evacuated and doping atmosphere backfilled wafer carrier having a window transparent to the wavelength of the laser beam, to allow illumination of the masked wafer when the carrier is inserted into a processing chamber of a laser processing system including an in-situ reflectivity monitor to measure the melt duration of the silicon.
- the laser beam typically emitted from an excimer laser, is shaped, homogenized, and at least one pulse is directed onto the SOS wafer to be processed.
- the laser pulse energy and pulse duration are set to obtain the optimal fluence impinging on the wafer in order to achieve photolytic or pyrolytic decomposition of the doping ambient and subsequent dopant incorporation. Subsequent illuminations may be desired to redistribute the dopant in an inert ambient depending on the job at hand.
- An object of the invention is to provide for a method of fabricating bipolar junction transistors in silicon-on-sapphire.
- Another object is to provide a fabrication technique relying upon the application of laser activation of implanted dopant in such a manner as to electrically activate the dopant without allowing undesirable diffusion along crystallographic defects (diffusion pipes).
- Another object is to provide a fabrication technique relying upon the application of an in-situ laser dopant incorporation process in such a manner as to electrically activate the dopant without allowing undesirable diffusion along crystallographic defects (diffusion pipes).
- Another object is to provide a fabrication technique which accommodates a poor crystal quality of available silicon-on-sapphire material.
- Another object is to provide a bipolar transistor fabrication technique capable of utilizing less than bulk quality silicon-on-sapphire films for bipolar applications with relaxed requirements to thereby potentially save costly epitaxy processing steps and subsequently increasing reliability and yield.
- Another object is to provide a fabrication technique which enables the implementation of the combined benefits offered by laser processing and SOS which include no significant wafer stress, ultra-shallow dopant profiles for vertical scaling, narrow base widths, dopant profile customization in addition to full dielectric isolation, improved radiation hardness and low collector-to-substrate capacitance.
- FIG. 1 is a schematic representation of the laser processing system associated with the aforedescribed process to enable the fabrication of semiconductor devices in accordance with this disclosed inventive concept.
- FIG. 2 shows a cross-section of a starting SOS material consisting of an epitaxially grown n-type layer on a n + layer on sapphire which acts as the buried collector.
- FIG. 3 depicts a structure of delineated silicon islands after a patterned potassium hydroxide etch.
- FIG. 4 shows laser activation of the implanted base region and redistribution of the dopant.
- FIG. 5 shows the photolithographic patterning to define areas for subsequent implantation and laser processing.
- FIG. 6 depicts a final laser processing step that simultaneously activates the emitter, collector, and the extrinsic base regions without affecting the intrinsic base junction depth.
- FIG. 7 shows a functional bipolar device after the step of sintering the device to form ohmic contact with the junctions.
- FIG. 8 is a block diagram setting forth the process flow described above.
- FIG. 9 is a graph depicting the relationship between melt duration and desired junction depth for bulk silicon and thick epitaxial silicon layers on sapphire.
- FIG. 10 shows I C versus V CE for npn bipolar transistor common emitter in SOS fabricated using the process of this inventive concept.
- a fabrication process for semiconductor devices utilizes a pulsed laser activation of ion implanted dopant atoms.
- the process flow described below is representative of a self-aligned process for discrete bipolar transistors and test structures such as ring oscillators. It is to be understood that variations in this process flow for different devices, mask sets, etc., can be accommodated, when the novel aspects of this inventive concept disclosed herein are practiced by those skilled in the art.
- FIG. 1 The laser system utilized to practice this fabrication process for semiconductor devices in accordance with this inventive concept of utilizing an excimer laser activation of ion implanted dopant is schematically shown in FIG. 1 and is similar to that described in U.S. patent application No. 07/501,707 by S. D. Russell, et al., entitled “Method for Laser-Assisted Silicon Etching Using Halocarbon Ambients” (NC 71,978) which also includes an in-situ reflectivity monitor to measure the melt duration of the silicon or other semiconductor material.
- Laser processing system 10 includes an excimer laser 20 that emits a beam 11° through an optical path system 30.
- the optical path system homogenizes, shapes and directs a beam 11' through a laser beam transparent window 41 into a processing chamber system 40 containing a suitable ambient gas 40' and onto a silicon or other suitable semiconductor wafer W or wafer die or packaged device which may be mounted on a platen 42.
- a gas mass flow controller system 50 is used to flow and pressurize the suitable ambient gas and purge gases with respect to the processing chamber system. Removal of initial ambient or reaction by-products is accomplished via a pumping station 60 connected to the process chamber system.
- a capacitive manometer-process control device 70 is attached to the process chamber to monitor the pressure of the suitable ambient gas.
- In situ monitoring/alignment system 100 is included for positioning of wafer W where the laser beam which will impinge on the wafer.
- System 100 may also include a beam diagnostic system, a reflectivity monitor, a laser alignment system, an in-situ monitoring system, and a temporal profile and energy measurement system which may be included to calibrate incident laser fluence.
- FIGS. 2-7 schematically show the process flow used for laser-assisted fabrication of bipolar transistors in SOS.
- a discrete npn transistor is shown for simplicity; similarly, vertical dimensions in these figures are exaggerated for clarity and do not represent the scale of the devices.
- FIG. 2 shows the cross-section of the starting SOS material consisting of an epitaxially grown n-type layer on an n + layer on sapphire which acts as the buried collector.
- the n + first epi-layer has received the DSPE improvement process discussed in the Background of the Invention, supra, or may be fabricated by alternate means which exhibit sufficient quality for epitaxial deposition.
- the wafers receive a standard clean prior to the growth of 1 K ⁇ of thermal oxide.
- the isolation mask photolithography (photo) step follows which delineates the silicon islands for dielectric isolation formed by subsequent buffered oxide etch (BOE), photoresist removal by oxygen plasma etching (ashing), and potassium hydroxide (KOH) etch of the silicon. The remaining oxide is then etched resulting in the structure shown in FIG. 3.
- BOE buffered oxide etch
- KOH potassium hydroxide
- the wafers receive a standard clean prior to the growth of 600 ⁇ of thermal oxide, and deposition of 7 K ⁇ of 100% aluminum (Al).
- the high reflectivity of the aluminum allows masking for selective laser processing on the wafers.
- the intrinsic base photo follows, with wet or dry etching of the aluminum to open areas to receive ion implanted dopant atoms.
- the intrinsic base junction obtains a shallow implant of boron atoms (of typical dose 2 ⁇ 10 13 /cm 2 at 35 keV).
- the capping oxide is then wet or dry etched and the photoresist ashed to allow laser activation of the implanted base region and redistribution of the dopant controlled by the laser system (FIG. 4) in accordance with this inventive concept to be discussed in detail below.
- melt depths of about 0.35 ⁇ m are obtained with melt durations of about 120 nsec.
- Typical intrinsic bases suitable for shallow bipolar transistors are formed with metallurgical junctions about 0.3 ⁇ m using 100 nsec melt durations (" ⁇ 1.6 J/cm 2 ).
- the Al mask is removed with a wet (Caros) etch, followed by a standard clean and the deposition of 5 K ⁇ of Low Temperature Oxide (LTO). Deposition of 7 K ⁇ of 100% Al follows, to be patterned for the final laser mask.
- the contact photo step is completed (FIG. 5), in order to define areas for later implantation and laser processing.
- the Al is wet etched, and the resist reflowed prior to plasma etching of the oxide, and ashing of the resist. These steps may be replaced with a dry etching process, if desired, without affecting the inventive concept disclosed herein.
- the extrinsic base photo and implant (5 ⁇ 10 15 BF 2 /cm 2 at 25 keV) follow, and the resist is ashed.
- the emitter/collector photo and implant (3 ⁇ 10 15 As/cm 2 at 50 keV) are completed and the resist ashed.
- the final laser processing step is completed with melt durations between about 20 to about 100 nsec depending on the desired base width. This simultaneously activates the emitter, collector contact, and the extrinsic base regions without affecting the intrinsic base junction depth, see FIG. 6, in accordance with this inventive concept to be discussed in detail below.
- the Al mask is removed by a wet (Caros) etch.
- a conventional rapid thermal anneal (RTA) may be employed to further anneal ion implant straggle damage. Residual implant damage does not exist if the in-situ dopant incorporation (GILD) process discussed in the Background of the Invention, supra, is used. In that case, and those with careful process controls, the RTA step can be eliminated.
- Conventional metallization steps follow including: a standard clean, 10:1 hydrofluoric (HF) acid dip to clear native oxide, deposition of 1 K ⁇ titanium (Ti) and 10 K ⁇ of 99%AL-1%Si.
- Patterning of the metal includes a photo step, wet etching the Al and Ti, dehazing (removing Si deposits), and ashing the resist. Finally, sintering of the device to form ohmic contact with the junctions provides the functional bipolar device shown in FIG. 7.
- the aforedescribed process flow with figure correlations to the above sequence is summarized in FIG. 8 with the associated braces relating the steps of the process to the figures of the drawings.
- the method for laser-assisted dopant activation in SOS involves the above identified steps which are used to provide a patterned 100% aluminum mask whose function is to reflect the laser light from regions where melting of the silicon is undesirable (for example, in previously processed regions).
- the SOS wafer W to be processed is then placed within a chamber such as that referred to above or, optionally, the wafer may be placed in a wafer carrier, not shown, that is evacuated and backfilled with an inert atmosphere.
- the wafer carrier is provided with a window transparent to the wavelength of the laser beam, allowing illumination of the masked wafer after the wafer carrier is inserted into the laser processing system of FIG. 1.
- Excimer laser beam 11° is shaped, homogenized, and then one or more pulses 11' are directed onto the wafer to be processed in accordance with the process steps as indicated by "A" and "B” in FIG. 8.
- the laser pulse energy and pulse duration are set to obtain the optimal fluence impinging on the wafer in order to achieve the desired melt duration and corresponding junction depth.
- the relationship among these parameters for bulk silicon and thick (at least one micrometer) epitaxial silicon layers on sapphire are shown in FIG. 9 for a XeCl excimer laser operating at 308 nm wavelength.
- the range of available melt durations, without ablating, is from about 20 nsec to about 120 nsec corresponding to junction depths of about 100 ⁇ to about 3500 ⁇ .
- the melt regime is between about 0.4 J/cm 2 and about 2.5 J/cm 2 with an excimer laser beam wavelength of 308 nm.
- this process enables the implementation of the combined benefits offered by laser processing and SOS which include no significant wafer heating, ultra-shallow dopant profiles for vertical scaling, narrow base widths, dopant profile customization in addition to full dielectric isolation, improved radiation hardness and low collector to substrate capacitance.
- This process is designed to minimize problems associated with SOS material quality; however, the process can be used for bulk Si, and other SOI technologies. The converse is not true, conventional processing techniques cannot be used for the fabrication of devices in SOS.
- this process may be extended to processing on materials to inhibit unwanted diffusion of dopant in both vertical and lateral device structures.
- An alternative which may be beneficial in some applications is the use of the laser process to activate only the emitter/collector implant after conventional furnace annealing of the base implant, or only laser activate the emitter implant. These variations in the process also generates functional devices since diffusion of dopant along the crystallographic defect pipes is minimal, preventing emitter-collector shorts.
- GILD in-situ dopant incorporation
- the 100% Al mask referred to above has demonstrated highest reflectivity when deposited without preheating the wafer, and in a load locked sputtering system.
- the higher reflectivity allows the use of higher laser fluences to achieve greater melt (junction) depths without ablation of the mask at UV wavelengths.
- Variations in masking schemes may be appropriate for different laser systems, for example, changing the metal used and/or metal thickness, masking with oxides or even maskless processing by projecting the laser beam in a desired pattern.
- masks which are predominantly aluminum have been demonstrated appropriate for excimer laser processing.
- Variations of Si layer thickness will also require modifications of the method disclosed above due to variation of the thermal properties of the sapphire substrate as compared to bulk silicon.
- Laser wavelength may be varied in order to vary the decomposition mechanism of the ambient gas described in the in-situ dopant incorporation (GILD) process, and the absorption depth in the sample to optimize specific production requirements, for example ultra-shallow junctions.
- GILD in-situ dopant incorporation
- HBTs Ge-Si heterojunction bipolar transistors
Abstract
The fabrication of bipolar junction transistors in silicon-on-sapphire (SOS) relies upon the laser-assisted dopant activation in SOS. A patterned 100% aluminum mask whose function is to reflect laser light from regions where melting of the silicon is undesirable is provided on an SOS wafer to be processed. The wafer is placed within a wafer carrier that is evacuated and backfilled with an inert atmosphere and that is provided with a window transparent to the wavelength of the laser beam to allow illumination of the masked wafer when the carrier is inserted into a laser processing system. A pulsed laser (typically an excimer laser) beam is appropriately shaped and homogenized and one or more pulses are directed onto the wafer. The laser beam pulse energy and pulse duration are set to obtain the optimal fluence impinging on the wafer in order to achieve the desired melt duration and corresponding junction depth. Care must be taken since activation and rapid dopant redistribution occurs when the laser fluence is above the melt threshold and below the ablation threshold. Thus, bipolar junction transistors in SOS utilize a pulsed laser activation of ion implanted dopant atoms. Appropriate masking and pulsed laser illumination assures the electrical activation of the dopant without allowing undesirable diffusion either vertically along crystallographic defects (diffusion pipes) or laterally.
Description
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
Very Large Scale Integration (VLSI) of microelectronic devices and future downscaling of electronic systems require dielectric isolation to overcome problems associated with conventional junction isolation such as: latch-up, unscalable vertical dimensions, and increased leakage at elevated temperatures, see the artical by S. J. Duey and G. W. Neudeck, "A Novel Quasi-Dielectrically Isolated Bipolar Transistor Using Epitaxial Lateral Overgrowth", in J. Jopke, ed., Proceddings of the 1988 Bipolar Circuits & Technology Meeting, 1988, pp. 241-244. Methods to acieve this dielectric isolation are silicon-on-insulator (SOI) technologies. SOI technologies promise to offer increased device performance by reducing parasitic capacitance, interconnect delay, and increased radiation hardness. Many examples of SOI technologies are known, but with limited degrees of success and process maturity, for example, see the article by J. Jastrzebski, "Silicon on Insulators: Different Approaches: A Review", J. Crystal Growth, vol. 70, 1984, p. 253. In SOI technology, small islands of silicon which contain the individual device are fabricated on an insulating substrate, and then interconnected in the normal way. Likely to be attendant with these technologies is the difficulty, or inability to achieve "device quality" silicon on an insulating layer. Device quality is defined as silicon layers without crystallographic defects and/or impurities which prevent fabrication of functioning devices. One SOI technique employs the ion implantation of oxygen or nitrogen into bulk silicon forming a buried oxide (SiO2) called the SIMOX process, as described by M. K. El-Ghor, S. J. Pennycook, F. Namavar, and N. H., Karam in "Formation of Low Dislocation Density Silicon-on-Insulator by a Single Implantation and Annealing", Appl. Phys. Lett., vol. 57, 1990, p. 156, or a buried nitride (Si3 N4) layer. Other techniques relied on deposited amorphous or polycrystalline silicon on an amorphous substrate and then recrystallized by various techniques such as laser annealing, electron beam annealing and radiant heating. These methods did not achieve high quality devices and the techniques have been subsequently abandoned, note S. Wolf and R. N. Tauber's Silicon Processing for the VLSI Era, Vol. 1: Process Technology, Lattice Press, Sunset Beach, Calif., pp. 153-5. Epitaxial Lateral Overgrowth (ELO) is a method which employs the growth of an oxide layer on bulk silicon, and subsequent selective epitaxial growth from nucleation sites on bare silicon in patterned openings and subsequent overgrowth on the remaining oxide, see Duey et al., supra. A similar technique called Zone Melt Recrystallization (ZMR) uses a moving filament to remelt silicon deposited on SiO2 using patterned openings to the bulk Si below as a seed crystal for regrowth, note the article by G. A. Rozgonyi et al., "Structural and Electrical Properties of Epitaxial Si on Insulating Substrates", Appl. Phys. Lett., vol. 55, 1989, p. 586.
Another technology that has been investigated employs epitaxially grown silicon-on-sapphire (SOS). Early attempts at fabricating device quality SOS have been documented, for example, see G. W. Cullen's "The Preparation and Properties of Chemically Vapor Deposited Silicon on Sapphire and Spinel", J. Crystal Growth, vol. 9, 1971, p. 107 and F. P. Heiman and P. H. Robinson's "Silicon-On-Sapphire Epitaxial Bipolar Transistors", Solid State Electronics, vol. 11, 1968, p. 411. This latter reference achieved low gain functional transistors, but noted that small area devices must be fabricated because of the high density of crystal imperfections that cause emitter-collector shorts. Since then, techniques have been developed to improve the near interfacial region for thin silicon layers on sapphire such as Solid-Phase-Epitaxy (SPE), Double-Solid-Phase-Epitaxy (DSPE) and Solid-Phase-Epitaxy-And-Regrowth (SPEAR), see for example, the article by S. Lau et al., "Improvement of Crystalline Quality of Epitaxial Si Layers by Ion Implantation Techniques", Appl. Phys. Lett., Vol. 34, 1979, p. 76; G. A. Garcia and R. E. Reedy, "Electron Mobility within 100 nm of the Si/Sapphire Interface in Double-Solid-Phase Epitaxially Regrown SOS", Electronics Letters, Vol. 22, 1986, p. 537; and D. C. Mayer et al., "A Short-Channel CMOS/SOS Technology in Recrystallized 0.3 μm-thick Silicon-on-Sapphire Films", IEEE Electron. Dev. Lett., Vol. EDL-5, 1984, p. 156. These techniques, however, do not provide device quality material for devices with more stringent materials requirements such as bipolar junction transistors, charge-coupled devices (CCDs), and others, requiring thicker films and high quality epitaxial layers, see L. Jastrzebski's "Origin and Control of Material Defects in Silicon VLSI Technologies: An Overview", IEEE Trans. Electron Dev., Vol. ED-29, 1982, p. 475. Previous attempts at fabrication of bipolar devices in SOS have been blocked by materials defects. The inability to achieve silicon epitaxially grown on sapphire without dislocations, slip planes, and twin defects results in a failure mechanism for devices by means of what is known as "diffusion pipes". Diffusion pipes are crystallographic defects which allow paths for dopant atoms to diffuse (or migrate) during high temperature anneals. The anneals are critical in the processing of semiconductor devices in that they allow the electrical activation of ion implanted dopant atoms. Therefore the diffusion of dopant from one junction into another (e.g. the emitter to the base) results in leaky or shorted devices. Therefore, research and development into high quality crystalline films on sapphire and novel processing techniques are of continuing interest for SOS device fabrication.
Laser processing of materials has been investigated for a variety of applications, and is being used in semiconductor processing of silicon VLSI in applications which range from laser-assisted etching, as referred to in S. D. Russell and D. A. Sexton's "Excimer Laser-Assisted Etching of Silicon Using Chloropentafluoroethane", in R. Rosenberg et al., In-Situ Patterning: Selective Area Deposition and Etching" Mater. Res. Soc. Proc., vol. 158, 1990, p. 325; chemical vapor deposition (CVD), as referred to by D. Lubben et al. in "Laser-Induced Plasmas for Primary Ion Deposition of Epitaxial Ge and Si Films", J. Vac. Sci. Technol., B, vol. 3, 1985, p. 968; and alloy formation, as referred to by J. R. Abelson et al. in "Epitaxial Gex Si-x /Si (100) Structures Produced by Pulsed Laser Mixing of Evaporated Ge on Si (100) Substrates", Appl. Phys. Lett., vol. 52, 1988, p. 230, to name a few. Laser activation of ion implanted dopant has long been known as an alternative to conventional furnace annealing, see for example, A. E. Bell's "Review and Analysis of Laser Annealing", RCA Review, vol. 40, 1979, p. 295; and L. D. Hess et al. in "Applications of Laser Annealing in IC Fabrication"; in, J. Narayan et al., eds., Laser-Solid Interactions and Transient Thermal Processing of Materials, Mat. Res. Soc. Symp. Proc., vol. 13, 1983, p. 337; and techniques such as Gas Immersion Laser Doping (GILD) have proven valuable in the formation of shallow junctions in bulk silicon, note R. J. Pressley's "Gas Immersion Laser Diffusion (GILDing)", in C. C. Tang, ed., "Laser Processing of Semiconductor Devices", Proc. SPIE, vol. 385, 1983, p. 30.; and K. H. Weiner and T. W. Sigmon's "Thin-Base Bipolar Transistor Fabrication Using Gas Immersion Laser Doping", IEEE Electron Dev. Lett., vol. 10, 1989, p. 260. In addition, examination of excimer laser annealing of implant damage in bulk silicon has been demonstrated in the article by D. H. Lowndes et al., "Pulsed Excimer Laser (308 nm) Annealing of Ion Implanted Silicon and Solar Cell Fabrication", in J. Narayan et al., Laser-Solid Interactions and Transient Thermal Processing of Materials, Mat. Res. Soc. Symp. Proc., vol. 13, 1983, p. 407. These studies have, however, been limited to processing high quality bulk silicon, and have not explored the unique requirements of SOS.
Reports on laser processing SOS have not examined techniques required to solve materials problems for bipolar transistors and related demanding technologies. Yamada et al. performed thermally-assisted pulse laser annealing of SOS, see M. Yamada et al., "Thermally-Assisted Pulsed-Laser Annealing of SOS", in J. F. Gibbons et al., eds, Laser and Electron-Beam Solid Interactions and Materials Processing, Mat. Res. Soc. Symp. Proc., vol. 1, 1981, p. 503. Using Raman spectroscopy they measured the residual strain in annealed SOS due to the lattice mismatch between Si and sapphire. They performed no examination of laser dopant activation. Alestig et al. performed continuous wave (cw) laser annealing of ion implanted oxidized silicon layers on sapphire, see the article by G. Alestig et al., "CW Laser Annealing of Ion Implanted Oxidized Silicon Layers on Sapphire", in J Narayan et al., eds., Laser-Solid Interactions and Transient Thermal Processing of Materials, Mat. Res. Soc. Symp. Proc., vol. 13, 1983, p. 517. They demonstrated activation of boron and phosphorous dopants by illumination from both the top and backside of the wafer. They reported visible damage was obtained when using power sufficient to melt the silicon. Similarly, Hess et al. performed cw laser annealing of SOS to activate ion implanted dopant into MOS devices, see the article by L. D. Hess et al., "Laser-Assisted MOS/SOS Transistor Fabrication", in B. R. Appleton and G. K. Celler, eds., Laser and Electron-Beam Interactions with Solids, Mat. Res. Soc. Symp. Proc., vol. 4, 1982, p. 633. To prevent diffusion of dopant from the source or drain region into the gate region, the silicon was not melted to prevent spatial redistribution of the dopant. These references teach away from the use of melting SOS to prevent unwanted diffusion of dopant, and report decreased crystalline quality under these conditions.
Thus, a continuing need exists for a method of using a pulsed laser to perform a rapid melting of a select portion of a silicon island on sapphire, thereby diffusing dopant to electrically active sites without allowing time for undesirable diffusion along defect pipes to eliminate the problems associated with standard annealing techniques, to provide a uniform dopant profile desirable for bipolar bases, to effectively decouple the thermal activation of the emitter and base regions, and to provide for the advantage of fabricating functional devices in SOS material that has significant defects. The need further exists for such a technique that can be extended to fabrication of other semiconductor devices in SOS requiring activation of dopant atoms such as MOSFETs, CCDs, etc., and is amenable to process modifications to accommodate emerging materials, e.g. silicon-germanium alloys.
The present invention is directed to providing a method for the fabrication of bipolar junction transistors by laser-assisted dopant activation in silicon-on-sapphire (SOS). A patterned 100% aluminum mask is provided for an SOS wafer whose function is to reflect laser light from regions where melting of the silicon is undesirable (for example, in previously processed regions). The SOS wafer to be processed is then placed within an evacuated and inert atmosphere backfilled wafer carrier having a window transparent to the wavelength of the laser beam, to allow illumination of the masked wafer when the carrier is inserted into a processing chamber of a laser processing system including an in-situ reflectivity monitor to measure the melt duration of the silicon. The laser beam, typically emitted from an excimer laser, is shaped, homogenized, and at least one pulse is directed onto the SOS wafer to be processed. The laser pulse energy and pulse duration are set to obtain the optimal fluence impinging on the wafer in order to achieve the desired melt duration and corresponding junction depth. Alternately, an in-situ laser-assisted dopant incorporation process (referred to as GILD in the Background of the Invention, supra) where the patterned SOS wafer to be processed is placed within an evacuated and doping atmosphere backfilled wafer carrier having a window transparent to the wavelength of the laser beam, to allow illumination of the masked wafer when the carrier is inserted into a processing chamber of a laser processing system including an in-situ reflectivity monitor to measure the melt duration of the silicon. The laser beam, typically emitted from an excimer laser, is shaped, homogenized, and at least one pulse is directed onto the SOS wafer to be processed. The laser pulse energy and pulse duration are set to obtain the optimal fluence impinging on the wafer in order to achieve photolytic or pyrolytic decomposition of the doping ambient and subsequent dopant incorporation. Subsequent illuminations may be desired to redistribute the dopant in an inert ambient depending on the job at hand. Typical values used for bulk silicon and thick (at least one micrometer) epitaxial silicon layers on sapphire to achieve a base depth of 0.3 μm is a melt duration of about 100 ns (.o slashed.˜1.6 J/cm2); and an emitter depth of 0.15 μm is obtained with a melt duration of about 55 ns (.o slashed.=1.2 J/cm2), where .o slashed. is the incident fluence. Dopant activation and rapid redistribution occurs in the wafer when the laser fluence is above the melt threshold and below the ablation threshold so that the wafer can be removed from the processing chamber for subsequent processing.
An object of the invention is to provide for a method of fabricating bipolar junction transistors in silicon-on-sapphire.
Another object is to provide a fabrication technique relying upon the application of laser activation of implanted dopant in such a manner as to electrically activate the dopant without allowing undesirable diffusion along crystallographic defects (diffusion pipes).
Another object is to provide a fabrication technique relying upon the application of an in-situ laser dopant incorporation process in such a manner as to electrically activate the dopant without allowing undesirable diffusion along crystallographic defects (diffusion pipes).
Another object is to provide a fabrication technique which accommodates a poor crystal quality of available silicon-on-sapphire material.
Another object is to provide a bipolar transistor fabrication technique capable of utilizing less than bulk quality silicon-on-sapphire films for bipolar applications with relaxed requirements to thereby potentially save costly epitaxy processing steps and subsequently increasing reliability and yield.
Another object is to provide a fabrication technique which enables the implementation of the combined benefits offered by laser processing and SOS which include no significant wafer stress, ultra-shallow dopant profiles for vertical scaling, narrow base widths, dopant profile customization in addition to full dielectric isolation, improved radiation hardness and low collector-to-substrate capacitance.
These and other objects of the invention will become more readily apparent from the ensuing specification and drawings when taken in conjunction with the appended claims.
FIG. 1 is a schematic representation of the laser processing system associated with the aforedescribed process to enable the fabrication of semiconductor devices in accordance with this disclosed inventive concept.
FIG. 2 shows a cross-section of a starting SOS material consisting of an epitaxially grown n-type layer on a n+ layer on sapphire which acts as the buried collector.
FIG. 3 depicts a structure of delineated silicon islands after a patterned potassium hydroxide etch.
FIG. 4 shows laser activation of the implanted base region and redistribution of the dopant.
FIG. 5 shows the photolithographic patterning to define areas for subsequent implantation and laser processing.
FIG. 6 depicts a final laser processing step that simultaneously activates the emitter, collector, and the extrinsic base regions without affecting the intrinsic base junction depth.
FIG. 7 shows a functional bipolar device after the step of sintering the device to form ohmic contact with the junctions.
FIG. 8 is a block diagram setting forth the process flow described above.
FIG. 9 is a graph depicting the relationship between melt duration and desired junction depth for bulk silicon and thick epitaxial silicon layers on sapphire.
FIG. 10 shows IC versus VCE for npn bipolar transistor common emitter in SOS fabricated using the process of this inventive concept.
A fabrication process for semiconductor devices utilizes a pulsed laser activation of ion implanted dopant atoms. The process flow described below is representative of a self-aligned process for discrete bipolar transistors and test structures such as ring oscillators. It is to be understood that variations in this process flow for different devices, mask sets, etc., can be accommodated, when the novel aspects of this inventive concept disclosed herein are practiced by those skilled in the art.
The laser system utilized to practice this fabrication process for semiconductor devices in accordance with this inventive concept of utilizing an excimer laser activation of ion implanted dopant is schematically shown in FIG. 1 and is similar to that described in U.S. patent application No. 07/501,707 by S. D. Russell, et al., entitled "Method for Laser-Assisted Silicon Etching Using Halocarbon Ambients" (NC 71,978) which also includes an in-situ reflectivity monitor to measure the melt duration of the silicon or other semiconductor material.
A gas mass flow controller system 50 is used to flow and pressurize the suitable ambient gas and purge gases with respect to the processing chamber system. Removal of initial ambient or reaction by-products is accomplished via a pumping station 60 connected to the process chamber system. A capacitive manometer-process control device 70, for example, is attached to the process chamber to monitor the pressure of the suitable ambient gas. In situ monitoring/alignment system 100 is included for positioning of wafer W where the laser beam which will impinge on the wafer. System 100 may also include a beam diagnostic system, a reflectivity monitor, a laser alignment system, an in-situ monitoring system, and a temporal profile and energy measurement system which may be included to calibrate incident laser fluence. The details of the typical constituents of examples of these systems can be gleaned from the above referenced application and will make an implementation and/or variations readily apparent to those skilled in the art so that an appreciation of the salient features of this inventive concept can be made known.
FIGS. 2-7 schematically show the process flow used for laser-assisted fabrication of bipolar transistors in SOS. A discrete npn transistor is shown for simplicity; similarly, vertical dimensions in these figures are exaggerated for clarity and do not represent the scale of the devices.
FIG. 2 shows the cross-section of the starting SOS material consisting of an epitaxially grown n-type layer on an n+ layer on sapphire which acts as the buried collector. The n+ first epi-layer has received the DSPE improvement process discussed in the Background of the Invention, supra, or may be fabricated by alternate means which exhibit sufficient quality for epitaxial deposition. The wafers receive a standard clean prior to the growth of 1 KÅ of thermal oxide. The isolation mask photolithography (photo) step follows which delineates the silicon islands for dielectric isolation formed by subsequent buffered oxide etch (BOE), photoresist removal by oxygen plasma etching (ashing), and potassium hydroxide (KOH) etch of the silicon. The remaining oxide is then etched resulting in the structure shown in FIG. 3.
The wafers receive a standard clean prior to the growth of 600 Å of thermal oxide, and deposition of 7 KÅ of 100% aluminum (Al). The high reflectivity of the aluminum allows masking for selective laser processing on the wafers. The intrinsic base photo follows, with wet or dry etching of the aluminum to open areas to receive ion implanted dopant atoms. The intrinsic base junction obtains a shallow implant of boron atoms (of typical dose 2×1013 /cm2 at 35 keV). The capping oxide is then wet or dry etched and the photoresist ashed to allow laser activation of the implanted base region and redistribution of the dopant controlled by the laser system (FIG. 4) in accordance with this inventive concept to be discussed in detail below.
Maximum melt depths of about 0.35 μm are obtained with melt durations of about 120 nsec. Typical intrinsic bases suitable for shallow bipolar transistors are formed with metallurgical junctions about 0.3 μm using 100 nsec melt durations ("˜1.6 J/cm2).
The Al mask is removed with a wet (Caros) etch, followed by a standard clean and the deposition of 5 KÅ of Low Temperature Oxide (LTO). Deposition of 7 KÅ of 100% Al follows, to be patterned for the final laser mask. The contact photo step is completed (FIG. 5), in order to define areas for later implantation and laser processing. The Al is wet etched, and the resist reflowed prior to plasma etching of the oxide, and ashing of the resist. These steps may be replaced with a dry etching process, if desired, without affecting the inventive concept disclosed herein. The extrinsic base photo and implant (5×1015 BF2 /cm2 at 25 keV) follow, and the resist is ashed. The emitter/collector photo and implant (3×1015 As/cm2 at 50 keV) are completed and the resist ashed. The final laser processing step is completed with melt durations between about 20 to about 100 nsec depending on the desired base width. This simultaneously activates the emitter, collector contact, and the extrinsic base regions without affecting the intrinsic base junction depth, see FIG. 6, in accordance with this inventive concept to be discussed in detail below.
The Al mask is removed by a wet (Caros) etch. At this stage, a conventional rapid thermal anneal (RTA) may be employed to further anneal ion implant straggle damage. Residual implant damage does not exist if the in-situ dopant incorporation (GILD) process discussed in the Background of the Invention, supra, is used. In that case, and those with careful process controls, the RTA step can be eliminated. Conventional metallization steps follow including: a standard clean, 10:1 hydrofluoric (HF) acid dip to clear native oxide, deposition of 1 KÅ titanium (Ti) and 10 KÅ of 99%AL-1%Si. Patterning of the metal includes a photo step, wet etching the Al and Ti, dehazing (removing Si deposits), and ashing the resist. Finally, sintering of the device to form ohmic contact with the junctions provides the functional bipolar device shown in FIG. 7.
The aforedescribed process flow with figure correlations to the above sequence is summarized in FIG. 8 with the associated braces relating the steps of the process to the figures of the drawings. The method for laser-assisted dopant activation in SOS involves the above identified steps which are used to provide a patterned 100% aluminum mask whose function is to reflect the laser light from regions where melting of the silicon is undesirable (for example, in previously processed regions). The SOS wafer W to be processed is then placed within a chamber such as that referred to above or, optionally, the wafer may be placed in a wafer carrier, not shown, that is evacuated and backfilled with an inert atmosphere. Like the aforedescribed chamber 40, the wafer carrier is provided with a window transparent to the wavelength of the laser beam, allowing illumination of the masked wafer after the wafer carrier is inserted into the laser processing system of FIG. 1.
This process is designed to minimize problems associated with SOS material quality; however, the process can be used for bulk Si, and other SOI technologies. The converse is not true, conventional processing techniques cannot be used for the fabrication of devices in SOS.
In addition, this process may be extended to processing on materials to inhibit unwanted diffusion of dopant in both vertical and lateral device structures.
An alternative which may be beneficial in some applications is the use of the laser process to activate only the emitter/collector implant after conventional furnace annealing of the base implant, or only laser activate the emitter implant. These variations in the process also generates functional devices since diffusion of dopant along the crystallographic defect pipes is minimal, preventing emitter-collector shorts.
Application of the in-situ dopant incorporation (GILD) process described in the Background of the Invention supra, will also enable laser activation of the dopant by the optional replacing of the two-step implantation/laser anneal process disclosed in the preferred embodiment. In this case a doping ambient with pressures near or below one atmosphere (between 10-4 torr to 2000 torr) is decomposed by the laser and redistributed into the semiconductor film. Typically, the doping ambient could be boron trifluoride, arsine or phosphine, for example, although others could be chosen under appropriate conditions.
The 100% Al mask referred to above has demonstrated highest reflectivity when deposited without preheating the wafer, and in a load locked sputtering system. The higher reflectivity allows the use of higher laser fluences to achieve greater melt (junction) depths without ablation of the mask at UV wavelengths. Variations in masking schemes may be appropriate for different laser systems, for example, changing the metal used and/or metal thickness, masking with oxides or even maskless processing by projecting the laser beam in a desired pattern. However, masks which are predominantly aluminum have been demonstrated appropriate for excimer laser processing.
Variations of Si layer thickness will also require modifications of the method disclosed above due to variation of the thermal properties of the sapphire substrate as compared to bulk silicon. Laser wavelength may be varied in order to vary the decomposition mechanism of the ambient gas described in the in-situ dopant incorporation (GILD) process, and the absorption depth in the sample to optimize specific production requirements, for example ultra-shallow junctions.
This process may also be extended to other materials and structures, for example, Ge-Si heterojunction bipolar transistors (HBTs), since shallow penetration depths and rapid annealing are desirable in similar technologies.
Obviously, many modifications and variations in the above described process flow may be made for different devices, mask sets, etc., and are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
Claims (30)
1. A method for laser-assisted dopant activation and rapid dopant redistribution while inhibiting the creation of undesirable diffusion in a silicon-on-sapphire wafer comprising:
placing said silicon-on-sapphire wafer in an appropriate ambient; and
generating an appropriately shaped and spatially homogenized laser beam having a pulse energy and pulse duration preset to above the melt threshold and below the ablation threshold of said silicon of said silicon-on-sappire wafer to obtain a predetermined optimal fluence in order to achieve a desired melt duration and corresponding junction depth; and
directing said appropriately shaped and homogenized laser beam of at least one pulse onto said silicon-on-sapphire wafer in a predetermined processing location thereon to ensure said dopant activation and said rapid dopant redistribution while said inhibiting the creation of undesirable diffusion in said silicon-on-sapphire wafer.
2. A method according to claim 1 further including:
providing a patterned mask on said silicon-on-sapphire wafer to reflect impinging emissions from regions on said silicon-on-sapphire wafer where melting of the silicon is undesirable to achieve said predetermined processing location.
3. A method according to claim 1 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth is defined therein.
4. A method according to claim 2 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth is defined therein.
5. A method according to claims 1, 2, 3 or 4 in which the step of said generating is with said pulse energy between 0.4 J/cm2 and 2.5 J/cm2 with said laser beam at a wavelength of 308 nm.
6. A method according to claim 5 in which the step of said generating is with said desired melt duration between 20 nsec and 120 nsec.
7. A method according to claim 2 further including:
the step of said providing of said patterned mask on said silicon-on sapphire wafer is a mask of predominantly composed of aluminum.
8. A method for laser-assisted dopant activation and rapid dopant redistribution to create a bipolar junction transistor on a silicon-on-sapphire wafer while inhibiting the creation of undesirable diffusion in the creation of said bipolar junction transistor comprising:
placing said silicon-on-sapphire wafer in an appropriate ambient; and
generating an appropriately shaped and spatially homogenized laser beam having a pulse energy and pulse duration preset to above the melt threshold and below the ablation threshold of said silicon of said silcon-on-sapphire wafer to obtain a predetermined optimal fluence in order to achieve a desired melt duration and corresponding junction depth; and
directing said appropriately shaped and homogenized laser beam of at least one pulse onto said silicon-on-sapphire wafer in a predetermined processing location thereon to ensure said dopant activation and said rapid dopant redistribution while said inhibiting the creation of undesirable diffusion in the creation of said bipolar junction transistor on said silicon-on-sapphire wafer.
9. A method according to claim 8 further including:
providing a patterned mask on said silicon-on-sapphire wafer to create said bipolar junction transistor by reflecting impinging emissions from regions on said silicon-on-sapphire wafer where melting of the silicon is undesirable to achieve said predetermined processing location.
10. A method according to claim 8 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth in said bipolar junction transistor is defined therein.
11. A method according to claim 9 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth in said bipolar junction transistor is defined therein.
12. A method according to claims 8, 9, 10 or 11 in which the step of said generating is with said pulse energy between 0.4 J/cm2 and 2.5 J/cm2 with said laser beam at a wavelength of 308 nm.
13. A method according to claim 12 in which the step of said generating is with said desired melt duration between 20 nsec and 120 nsec.
14. A method according to claim 9 further including:
the step of said providing of said patterned mask on said silicon-on sapphire wafer is a mask of predominantly composed of aluminum.
15. A method for in-situ laser-assisted dopant incorporation, dopant activation and rapid dopant redistribution while inhibiting the creation of undesirable diffusion in a silicon-on-sapphire wafer comprising:
placing said silicon-on-sapphire wafer in an appropriate doing ambient; and
generating an appropriately shaped and spatially homogenized laser beam having a pulse energy and pulse duration preset to above the melt threshold and below the ablation threshold of said silicon of said silicon-on-sapphire wafer to obtain a predetermined optimal fluence in order to achieve a desired melt duration and corresponding junction depth; and
directing said appropriately shaped and homogenized laser beam of at least one pulse onto said silicon-on-sapphire wafer in a predetermined processing location thereon to ensure said dopant incorporation, said dopant activation and said rapid dopant redistribution while said inhibiting the creation of undesirable diffusion in said silicon-on-sapphire wafer.
16. A method according to claim 15 further including:
providing a patterned mask on said silicon-on-sapphire wafer to reflect impinging emissions from regions on said silicon-on-sapphire wafer where melting of the silicon is undesirable to achieve said predetermined processing location.
17. A method according to claim 15 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth is defined therein.
18. A method according to claim 16 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth is defined therein.
19. A method according to claims 15, 16, 17 or 18 in which the step of said generating is with said pulse energy between 0.4 J/cm2 and 2.5 J/cm2 with said laser beam at a wavelength of 308 nm.
20. A method according to claim 19 in which the step of said generating is with said desired melt duration between 20 nsec and 120 nsec.
21. A method according to claim 16 further including:
the step of said providing of said patterned mask on said silicon-on sapphire wafer is a mask of predominantly composed of aluminum.
22. A method according to claim 15 in which said doping ambient is at a pressure of between 10-4 torr to 2000 torr.
23. A method for laser-assisted dopant incorporation, dopant activation and rapid dopant redistribution to create a bipolar junction transistor while inhibiting the creation of undesirable diffusion in the creation of said bipolar junction transistor on a silicon-on-sapphire wafer while inhibiting the creation of undesirable diffusion in the creation of said bipolar junction transistor comprising:
placing said silicon-on-sapphire wafer in an appropriate doping ambient; and
generating an appropriately shaped and spatially homogenized laser beam having a pulse energy and pulse duration preset to above the melt threshold and below the ablation threshold of said silicon of said silicon-on-sapphire wafer to obtain a predetermined optimal fluence in order to achieve a desired melt duration and corresponding junction depth; and
directing said appropriately shaped and homogenized laser beam of at least one pulse onto said silicon-on-sapphire wafer in a predetermined processing location thereon to ensure said dopant incorporation, said dopant activation and said rapid dopant redistribution while said inhibiting the creation of undesirable diffusion in the creation of said bipolar junction transistor on said silicon-on-sapphire wafer.
24. A method according to claim 23 further including:
providing a patterned mask on said silicon-on-sapphire wafer to create said bipolar junction transistor by reflecting impinging emissions from regions on said silicon-on-sapphire wafer where melting of the silicon is undesirable to achieve said predetermined processing location.
25. A method according to claim 23 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth in said bipolar junction transistor is defined therein.
26. A method according to claim 24 in which the thickness of said silicon on said silicon-on-sapphire wafer is at least 1 micrometer and said corresponding junction depth in said bipolar junction transistor is defined therein.
27. A method according to claims 23, 24, 25 or 26 in which the step of said generating is with said pulse energy between 0.4 J/cm2 and 2.5 J/cm2 with said laser beam at a wavelength of 308 nm.
28. A method according to claim 27 in which the step of said generating is with said desired melt duration between 20 nsec and 120 nsec.
29. A method according to claim 24 further including:
the step of said providing of said patterned mask on said silicon-on sapphire wafer is a mask of predominantly composed of aluminum.
30. A method according to claim 23 in which the said doping ambient is at a pressure between 10-4 torr to 2000 torr.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/762,538 USH1637H (en) | 1991-09-18 | 1991-09-18 | Laser-assisted fabrication of bipolar transistors in silicon-on-sapphire (SOS) |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/762,538 USH1637H (en) | 1991-09-18 | 1991-09-18 | Laser-assisted fabrication of bipolar transistors in silicon-on-sapphire (SOS) |
Publications (1)
Publication Number | Publication Date |
---|---|
USH1637H true USH1637H (en) | 1997-03-04 |
Family
ID=25065341
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/762,538 Abandoned USH1637H (en) | 1991-09-18 | 1991-09-18 | Laser-assisted fabrication of bipolar transistors in silicon-on-sapphire (SOS) |
Country Status (1)
Country | Link |
---|---|
US (1) | USH1637H (en) |
Cited By (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5714793A (en) * | 1995-04-03 | 1998-02-03 | The United States Of America As Represented By The Secretary Of The Navy | Complementary vertical bipolar junction transistors formed in silicon-on-saphire |
US5858807A (en) * | 1996-01-17 | 1999-01-12 | Kabushiki Kaisha Toshiba | Method of manufacturing liquid crystal display device |
US6008144A (en) * | 1998-02-02 | 1999-12-28 | Industrial Technology Research | Window shutter for laser annealing |
US6344116B2 (en) | 1985-11-19 | 2002-02-05 | Raymond M. Warner, Jr. | Monocrystalline three-dimensional integrated-circuit technology |
US6514840B2 (en) * | 1999-04-13 | 2003-02-04 | International Business Machines Corporation | Micro heating of selective regions |
US20030157745A1 (en) * | 2002-02-19 | 2003-08-21 | Zeghbroeck Bart J. Van | Silicon carbide semiconductor devices with a regrown contact layer |
US20030157777A1 (en) * | 2002-02-19 | 2003-08-21 | Van Zeghbroeck Bart J. | Method of fabricating self-aligned silicon carbide semiconductor devices |
US6610143B2 (en) * | 2001-01-16 | 2003-08-26 | Semiconductor Components Industries Llc | Method of manufacturing a semiconductor component |
US6645454B2 (en) * | 2001-06-28 | 2003-11-11 | Sharp Laboratories Of America, Inc. | System and method for regulating lateral growth in laser irradiated silicon films |
US6660085B2 (en) * | 1998-07-13 | 2003-12-09 | Fujitsu Limited | Polycrystal thin film forming method and forming system |
US20040082191A1 (en) * | 2002-07-30 | 2004-04-29 | Zeghbroeck Bart J. Van | Wide bandgap semiconductor device construction |
US6790722B1 (en) | 2000-11-22 | 2004-09-14 | International Business Machines Corporation | Logic SOI structure, process and application for vertical bipolar transistor |
US20080203544A1 (en) * | 2007-02-26 | 2008-08-28 | Anderson Brent A | Semiconductor wafer structure with balanced reflectance and absorption characteristics for rapid thermal anneal uniformity |
US20080203523A1 (en) * | 2007-02-26 | 2008-08-28 | Anderson Brent A | Localized temperature control during rapid thermal anneal |
US20090096066A1 (en) * | 2007-10-10 | 2009-04-16 | Anderson Brent A | Structure and Method for Device-Specific Fill for Improved Anneal Uniformity |
US7605064B2 (en) | 2000-02-29 | 2009-10-20 | Agere Systems Inc. | Selective laser annealing of semiconductor material |
US20090308439A1 (en) * | 2008-06-11 | 2009-12-17 | Solar Implant Technologies Inc. | Solar cell fabrication using implantation |
US7692275B2 (en) | 2007-02-26 | 2010-04-06 | International Business Machines Corporation | Structure and method for device-specific fill for improved anneal uniformity |
US7745909B2 (en) | 2007-02-26 | 2010-06-29 | International Business Machines Corporation | Localized temperature control during rapid thermal anneal |
US20100323508A1 (en) * | 2009-06-23 | 2010-12-23 | Solar Implant Technologies Inc. | Plasma grid implant system for use in solar cell fabrications |
US20110162703A1 (en) * | 2009-03-20 | 2011-07-07 | Solar Implant Technologies, Inc. | Advanced high efficientcy crystalline solar cell fabrication method |
US20110192993A1 (en) * | 2010-02-09 | 2011-08-11 | Intevac, Inc. | Adjustable shadow mask assembly for use in solar cell fabrications |
US9318332B2 (en) | 2012-12-19 | 2016-04-19 | Intevac, Inc. | Grid for plasma ion implant |
US9324598B2 (en) | 2011-11-08 | 2016-04-26 | Intevac, Inc. | Substrate processing system and method |
US9343312B2 (en) * | 2014-07-25 | 2016-05-17 | Taiwan Semiconductor Manufacturing Company, Ltd. | High temperature intermittent ion implantation |
US20160372583A1 (en) * | 2014-03-07 | 2016-12-22 | Sumitomo Heavy Industries, Ltd. | Method of manufacturing semiconductor device and semiconductor device |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3943555A (en) * | 1974-05-02 | 1976-03-09 | Rca Corporation | SOS Bipolar transistor |
US3974560A (en) * | 1974-05-02 | 1976-08-17 | Rca Corporation | Method of making a bipolar transistor |
US4151008A (en) * | 1974-11-15 | 1979-04-24 | Spire Corporation | Method involving pulsed light processing of semiconductor devices |
US4249960A (en) * | 1979-06-18 | 1981-02-10 | Rca Corporation | Laser rounding a sharp semiconductor projection |
US4269631A (en) * | 1980-01-14 | 1981-05-26 | International Business Machines Corporation | Selective epitaxy method using laser annealing for making filamentary transistors |
US4377421A (en) * | 1979-09-12 | 1983-03-22 | Hitachi, Ltd. | Method of making a stacked emitter in a bipolar transistor by selective laser irradiation |
US4490211A (en) * | 1984-01-24 | 1984-12-25 | International Business Machines Corporation | Laser induced chemical etching of metals with excimer lasers |
US4758553A (en) * | 1983-12-09 | 1988-07-19 | Otsuka Pharmaceutical Factory, Inc. | Compositions of nucletic acid components for nutritional replenishment |
US4775641A (en) * | 1986-09-25 | 1988-10-04 | General Electric Company | Method of making silicon-on-sapphire semiconductor devices |
-
1991
- 1991-09-18 US US07/762,538 patent/USH1637H/en not_active Abandoned
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3943555A (en) * | 1974-05-02 | 1976-03-09 | Rca Corporation | SOS Bipolar transistor |
US3974560A (en) * | 1974-05-02 | 1976-08-17 | Rca Corporation | Method of making a bipolar transistor |
US4151008A (en) * | 1974-11-15 | 1979-04-24 | Spire Corporation | Method involving pulsed light processing of semiconductor devices |
US4249960A (en) * | 1979-06-18 | 1981-02-10 | Rca Corporation | Laser rounding a sharp semiconductor projection |
US4377421A (en) * | 1979-09-12 | 1983-03-22 | Hitachi, Ltd. | Method of making a stacked emitter in a bipolar transistor by selective laser irradiation |
US4269631A (en) * | 1980-01-14 | 1981-05-26 | International Business Machines Corporation | Selective epitaxy method using laser annealing for making filamentary transistors |
US4758553A (en) * | 1983-12-09 | 1988-07-19 | Otsuka Pharmaceutical Factory, Inc. | Compositions of nucletic acid components for nutritional replenishment |
US4490211A (en) * | 1984-01-24 | 1984-12-25 | International Business Machines Corporation | Laser induced chemical etching of metals with excimer lasers |
US4775641A (en) * | 1986-09-25 | 1988-10-04 | General Electric Company | Method of making silicon-on-sapphire semiconductor devices |
Non-Patent Citations (46)
Title |
---|
A. E. Bell, "Review and Analysis of Laser Annealing" RCA Review, vol. 40, p. 295 (1979). |
A. E. Bell, Review and Analysis of Laser Annealing RCA Review, vol. 40, p. 295 (1979). * |
D. C. Mayer, et al "A Short Channel CMOS/SOS Technology in Recrystallized 0.3 μm-Thick Silica-On Sapphire Flims" IEEE Electron Dev. Lett v.EDL-5 p. 15 (1984). |
D. C. Mayer, et al A Short Channel CMOS/SOS Technology in Recrystallized 0.3 m Thick Silica On Sapphire Flims IEEE Electron Dev. Lett v.EDL 5 p. 15 (1984). * |
D. H. Loundes, et al "Pulsed Excimer Laser (308 nm) Annealing of Ion Implanted Silicon and Solar Cell Fabrication" Mat Res. Soc. Symp Proc. V13 p. 407 (1983). |
D. H. Loundes, et al Pulsed Excimer Laser (308 nm) Annealing of Ion Implanted Silicon and Solar Cell Fabrication Mat Res. Soc. Symp Proc. V13 p. 407 (1983). * |
D. Lubben et al "Laser-Induced Plasmas for Primary Ion Deposition of Epitaxial Ge & Si Films" J. Vac. Sci Tech. B, v.3 p. 968 (1985). |
D. Lubben et al Laser Induced Plasmas for Primary Ion Deposition of Epitaxial Ge & Si Films J. Vac. Sci Tech. B, v.3 p. 968 (1985). * |
F. P. Heiman, et al "Silicon-On-Sapphire Epitaxial Bipolar Transistors" Solid State Electronics vol. 11, p. 411 (1968). |
F. P. Heiman, et al Silicon On Sapphire Epitaxial Bipolar Transistors Solid State Electronics vol. 11, p. 411 (1968). * |
G. A. Garcia, et al "Electron Mobility within 100 nm of the Si/Sapphire Interface in Double-Solid Phase Epitaxially Regrown SOS." Electronics Letters v.22 p. 537 (1986). |
G. A. Garcia, et al Electron Mobility within 100 nm of the Si/Sapphire Interface in Double Solid Phase Epitaxially Regrown SOS. Electronics Letters v.22 p. 537 (1986). * |
G. A. Rozgonyi, et al "Structural & Electrical Properties of Epitaxial Si in Insulating Substrates" Appl. Phys. Lett. v. 55, p. 586 (1989). |
G. A. Rozgonyi, et al Structural & Electrical Properties of Epitaxial Si in Insulating Substrates Appl. Phys. Lett. v. 55, p. 586 (1989). * |
G. Alestig, et al "CW Laser Annealing of Ion Implanted Oxidized Silicon Layers on Sapphire" Mat. Res. Soc. Symp Proc. vol. 13 p. 517 (1983). |
G. Alestig, et al CW Laser Annealing of Ion Implanted Oxidized Silicon Layers on Sapphire Mat. Res. Soc. Symp Proc. vol. 13 p. 517 (1983). * |
G. W. Cullen "The Preperation & Properties of Chemically Vapor Deposited Silicon on Sapphire & Spinel" J. Crystal Growth v.9 (1971) p. 107. |
G. W. Cullen The Preperation & Properties of Chemically Vapor Deposited Silicon on Sapphire & Spinel J. Crystal Growth v.9 (1971) p. 107. * |
J. Jastrzebski "Silicon on Insulators: Different Approaches: A Review" J. of Crystal Growth vol. 70, 1984, p. 253. |
J. Jastrzebski Silicon on Insulators: Different Approaches: A Review J. of Crystal Growth vol. 70, 1984, p. 253. * |
J. R. Abelson et al Epitaxial Ge x Si 1 x /Si(100) Structures Produced by Pulsed Laser Mixing of Evaporated Ge on Si(100) Substrates Appl. Phys. Lett, v.52, 1988, p. 230. * |
J. R. Abelson et al Epitaxial Gex Si1-x /Si(100) Structures Produced by Pulsed Laser Mixing of Evaporated Ge on Si(100) Substrates Appl. Phys. Lett, v.52, 1988, p. 230. |
K. H. Weiner, et al "Thin-Base Bipolar Transistor Fabrication Using Gas Immersion Laser Doping" IEEE Elec. Dev Lett vol. 10 p. 260 (1989). |
K. H. Weiner, et al Thin Base Bipolar Transistor Fabrication Using Gas Immersion Laser Doping IEEE Elec. Dev Lett vol. 10 p. 260 (1989). * |
L. D. Hess et al, "Laser-Assisted MOS/SOS Transistor Fabrication" in B. Appelton, et al eds, Laser and Electron-Beam Interactions with Solids Mat. Res. Soc. Symp. Proc. vol. 4, 1982 p. 633. |
L. D. Hess et al, Laser Assisted MOS/SOS Transistor Fabrication in B. Appelton, et al eds, Laser and Electron Beam Interactions with Solids Mat. Res. Soc. Symp. Proc. vol. 4, 1982 p. 633. * |
L. D. Hess, et al "Applications of Laser Annealing in IC Fabrication" Mat. Res Soc. Symp. Proc vol. 13, p. 337 (1983). |
L. D. Hess, et al Applications of Laser Annealing in IC Fabrication Mat. Res Soc. Symp. Proc vol. 13, p. 337 (1983). * |
L. Jastrzebski "Origin and Control of Material Defects in Silicon VLSI Technologies: An Overview" IEEE Trans Electron Dev p. 475 (1982) V.ED-29. |
L. Jastrzebski Origin and Control of Material Defects in Silicon VLSI Technologies: An Overview IEEE Trans Electron Dev p. 475 (1982) V.ED 29. * |
M. E. Roulet, et al "Laser Annealing of Silicon on Sapphire" J Appl. Phys. 50(8), Aug. 1979 pp. 5536-5538. |
M. E. Roulet, et al Laser Annealing of Silicon on Sapphire J Appl. Phys. 50(8), Aug. 1979 pp. 5536 5538. * |
M. K El Ghor, et al, "Formation of Low Dislocation Density Silicon-on-Insulator by a Single Implantation and Annealing" Appl Phys Lett vol. 57, p. 156 1990. |
M. K El Ghor, et al, Formation of Low Dislocation Density Silicon on Insulator by a Single Implantation and Annealing Appl Phys Lett vol. 57, p. 156 1990. * |
M. Yamada, et al "Thermally Assisted Pulsed-Laser Annealing of SOS" in J. Gibbons et al, eds. Laser & Electron-Beam Solid Interactions and Materials Processing. Mat. Res Soc Symp Proc vol. 1 1981 p. 503. |
M. Yamada, et al Thermally Assisted Pulsed Laser Annealing of SOS in J. Gibbons et al, eds. Laser & Electron Beam Solid Interactions and Materials Processing . Mat. Res Soc Symp Proc vol. 1 1981 p. 503. * |
R. J. Pressley s Gas Immersion Laser Diffusion (GILDing) in C C Tang, ed Laser Processing of Semiconductor Devices Proc SPIE v 385 p. 30 (1983). * |
R. J. Pressley's "Gas Immersion Laser Diffusion (GILDing)" in C C Tang, ed Laser Processing of Semiconductor Devices Proc SPIE v 385 p. 30 (1983). |
S. D. Russell, et al "Excimer Laser-Assisted Etching of Silicon Using Chloropentafluoroethane" In. Rosenberg et al In-Situ Patterning: Selective Area Deposition and Etching Mater. Res. Soc. Proc. vol. 158 p. 325 (1990). |
S. D. Russell, et al Excimer Laser Assisted Etching of Silicon Using Chloropentafluoroethane In. Rosenberg et al In Situ Patterning: Selective Area Deposition and Etching Mater. Res. Soc. Proc. vol. 158 p. 325 (1990). * |
S. J. Duey et al "A Novel Quasi-Dielectrically Isolated Bipolar Transistor Using Epitaxial Lateral Overgrowth" in Jopke ed Proceedings of the 1988 Bipolar Circuits & Technology Meeting (1988) pp. 241-244. |
S. J. Duey et al A Novel Quasi Dielectrically Isolated Bipolar Transistor Using Epitaxial Lateral Overgrowth in Jopke ed Proceedings of the 1988 Bipolar Circuits & Technology Meeting (1988) pp. 241 244. * |
S. Lau et al, "Improvement of Crystalline Quality of Epitaxial Si Layers by Ion Implantation Techniques" Appl Phys Lett vol. 34 p. 76 (1979). |
S. Lau et al, Improvement of Crystalline Quality of Epitaxial Si Layers by Ion Implantation Techniques Appl Phys Lett vol. 34 p. 76 (1979). * |
S. Wolf, et al Silicon Processing for The VLSI Era, vol. 1: Process Technology ; Latice Press Sunset Beach, CA (1986) pp. 153 155. * |
S. Wolf, et al Silicon Processing for The VLSI Era, vol. 1: Process Technology; Latice Press Sunset Beach, CA (1986) pp. 153-155. |
Cited By (46)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6344116B2 (en) | 1985-11-19 | 2002-02-05 | Raymond M. Warner, Jr. | Monocrystalline three-dimensional integrated-circuit technology |
US5714793A (en) * | 1995-04-03 | 1998-02-03 | The United States Of America As Represented By The Secretary Of The Navy | Complementary vertical bipolar junction transistors formed in silicon-on-saphire |
US5858807A (en) * | 1996-01-17 | 1999-01-12 | Kabushiki Kaisha Toshiba | Method of manufacturing liquid crystal display device |
US6008144A (en) * | 1998-02-02 | 1999-12-28 | Industrial Technology Research | Window shutter for laser annealing |
US6087277A (en) * | 1998-02-02 | 2000-07-11 | Industrial Technology Research Institute | Window shutter for laser annealing |
US6660085B2 (en) * | 1998-07-13 | 2003-12-09 | Fujitsu Limited | Polycrystal thin film forming method and forming system |
US6514840B2 (en) * | 1999-04-13 | 2003-02-04 | International Business Machines Corporation | Micro heating of selective regions |
US7605064B2 (en) | 2000-02-29 | 2009-10-20 | Agere Systems Inc. | Selective laser annealing of semiconductor material |
US6790722B1 (en) | 2000-11-22 | 2004-09-14 | International Business Machines Corporation | Logic SOI structure, process and application for vertical bipolar transistor |
US6610143B2 (en) * | 2001-01-16 | 2003-08-26 | Semiconductor Components Industries Llc | Method of manufacturing a semiconductor component |
US6645454B2 (en) * | 2001-06-28 | 2003-11-11 | Sharp Laboratories Of America, Inc. | System and method for regulating lateral growth in laser irradiated silicon films |
US7508000B2 (en) | 2002-02-19 | 2009-03-24 | Microsemi Corporation | Method of fabricating self-aligned silicon carbide semiconductor devices |
US6764907B2 (en) | 2002-02-19 | 2004-07-20 | Bart J. Van Zeghbroeck | Method of fabricating self-aligned silicon carbide semiconductor devices |
US20030157777A1 (en) * | 2002-02-19 | 2003-08-21 | Van Zeghbroeck Bart J. | Method of fabricating self-aligned silicon carbide semiconductor devices |
US20050224808A1 (en) * | 2002-02-19 | 2005-10-13 | Van Zeghbroeck Bart J | Silicon carbide semiconductor devices with a regrown contact layer |
US20050260821A1 (en) * | 2002-02-19 | 2005-11-24 | Van Zeghbroeck Bart J | Method of fabricating self-aligned silicon carbide semiconductor devices |
US6982440B2 (en) | 2002-02-19 | 2006-01-03 | Powersicel, Inc. | Silicon carbide semiconductor devices with a regrown contact layer |
US20030157745A1 (en) * | 2002-02-19 | 2003-08-21 | Zeghbroeck Bart J. Van | Silicon carbide semiconductor devices with a regrown contact layer |
US20040082191A1 (en) * | 2002-07-30 | 2004-04-29 | Zeghbroeck Bart J. Van | Wide bandgap semiconductor device construction |
US7241699B2 (en) | 2002-07-30 | 2007-07-10 | Microsemi Corp. | Wide bandgap semiconductor device construction |
US7679166B2 (en) | 2007-02-26 | 2010-03-16 | International Business Machines Corporation | Localized temperature control during rapid thermal anneal |
US20080203544A1 (en) * | 2007-02-26 | 2008-08-28 | Anderson Brent A | Semiconductor wafer structure with balanced reflectance and absorption characteristics for rapid thermal anneal uniformity |
US7692275B2 (en) | 2007-02-26 | 2010-04-06 | International Business Machines Corporation | Structure and method for device-specific fill for improved anneal uniformity |
US7745909B2 (en) | 2007-02-26 | 2010-06-29 | International Business Machines Corporation | Localized temperature control during rapid thermal anneal |
US7759773B2 (en) | 2007-02-26 | 2010-07-20 | International Business Machines Corporation | Semiconductor wafer structure with balanced reflectance and absorption characteristics for rapid thermal anneal uniformity |
US20080203523A1 (en) * | 2007-02-26 | 2008-08-28 | Anderson Brent A | Localized temperature control during rapid thermal anneal |
US20090096066A1 (en) * | 2007-10-10 | 2009-04-16 | Anderson Brent A | Structure and Method for Device-Specific Fill for Improved Anneal Uniformity |
US20090308439A1 (en) * | 2008-06-11 | 2009-12-17 | Solar Implant Technologies Inc. | Solar cell fabrication using implantation |
US20090309039A1 (en) * | 2008-06-11 | 2009-12-17 | Solar Implant Technologies Inc. | Application specific implant system and method for use in solar cell fabrications |
US8697553B2 (en) | 2008-06-11 | 2014-04-15 | Intevac, Inc | Solar cell fabrication with faceting and ion implantation |
US8871619B2 (en) | 2008-06-11 | 2014-10-28 | Intevac, Inc. | Application specific implant system and method for use in solar cell fabrications |
US20110162703A1 (en) * | 2009-03-20 | 2011-07-07 | Solar Implant Technologies, Inc. | Advanced high efficientcy crystalline solar cell fabrication method |
US9303314B2 (en) | 2009-06-23 | 2016-04-05 | Intevac, Inc. | Ion implant system having grid assembly |
US8697552B2 (en) | 2009-06-23 | 2014-04-15 | Intevac, Inc. | Method for ion implant using grid assembly |
US8749053B2 (en) | 2009-06-23 | 2014-06-10 | Intevac, Inc. | Plasma grid implant system for use in solar cell fabrications |
US8997688B2 (en) | 2009-06-23 | 2015-04-07 | Intevac, Inc. | Ion implant system having grid assembly |
US20100323508A1 (en) * | 2009-06-23 | 2010-12-23 | Solar Implant Technologies Inc. | Plasma grid implant system for use in solar cell fabrications |
US9741894B2 (en) | 2009-06-23 | 2017-08-22 | Intevac, Inc. | Ion implant system having grid assembly |
US20110192993A1 (en) * | 2010-02-09 | 2011-08-11 | Intevac, Inc. | Adjustable shadow mask assembly for use in solar cell fabrications |
US9324598B2 (en) | 2011-11-08 | 2016-04-26 | Intevac, Inc. | Substrate processing system and method |
US9875922B2 (en) | 2011-11-08 | 2018-01-23 | Intevac, Inc. | Substrate processing system and method |
US9583661B2 (en) | 2012-12-19 | 2017-02-28 | Intevac, Inc. | Grid for plasma ion implant |
US9318332B2 (en) | 2012-12-19 | 2016-04-19 | Intevac, Inc. | Grid for plasma ion implant |
US20160372583A1 (en) * | 2014-03-07 | 2016-12-22 | Sumitomo Heavy Industries, Ltd. | Method of manufacturing semiconductor device and semiconductor device |
US11239349B2 (en) * | 2014-03-07 | 2022-02-01 | Sumitomo Heavy Industries, Ltd. | Method of manufacturing semiconductor device and semiconductor device |
US9343312B2 (en) * | 2014-07-25 | 2016-05-17 | Taiwan Semiconductor Manufacturing Company, Ltd. | High temperature intermittent ion implantation |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
USH1637H (en) | Laser-assisted fabrication of bipolar transistors in silicon-on-sapphire (SOS) | |
EP0015677B1 (en) | Method of producing semiconductor devices | |
US5120394A (en) | Epitaxial growth process and growing apparatus | |
CN100573834C (en) | The manufacture method of semiconductor device and manufacture method thereof, semiconductor substrate | |
EP0052277B1 (en) | Semiconductor device and process for producing same | |
US4717681A (en) | Method of making a heterojunction bipolar transistor with SIPOS | |
EP0165971B1 (en) | Method of making a bipolar junction transistor | |
EP0558554B1 (en) | Silicon-on-porous-silicon; method of production and material | |
EP0536790A2 (en) | Method for producing semiconductor articles | |
Carey et al. | Ultra-shallow high-concentration boron profiles for CMOS processing | |
JPH06151344A (en) | Laser doping treatment method, insulated-gate semiconductor device and manufacture thereof | |
US7538030B2 (en) | Semiconductor device and method of manufacturing same | |
US5488012A (en) | Silicon on insulator with active buried regions | |
Hart et al. | Rapid thermal processing in semiconductor technology | |
KR970013198A (en) | Device isolation insulating film formation method of semiconductor device | |
JP2001044132A (en) | Manufacture of semiconductor device | |
US6204160B1 (en) | Method for making electrical contacts and junctions in silicon carbide | |
JP3210313B2 (en) | Method for improving characteristics of polycrystalline silicon thin film | |
EP0262034B1 (en) | Impurity doping method for the fabrication of semiconductor devices | |
JP3049806B2 (en) | Method for manufacturing thin film semiconductor device | |
Offord et al. | Laser Processing of Silicon On Sapphire (SOS) for Fabrication of Bipolar Transistors | |
Osgood | An Overview of Laser Chemical Processing | |
Russell et al. | Bipolar transistors in silicon-on-sapphire (SOS): effects of nanosecond thermal processing | |
Neudeck et al. | Fabrication of Polysilicon Contacted Emitter Bipolar Transistors | |
EP0621629A2 (en) | Method for reducing dislocations in integrated circuit devices |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: UNITED STATES OF AMERIC, THE, AS REPRESENTED BY TH Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:OFFORD, BRUCE W.;RUSSELL, STEPHEN D.;REEL/FRAME:005868/0723 Effective date: 19910909 |
|
AS | Assignment |
Owner name: UNITED STATES OF AMERICA, THE, AS REPRESENTED BY T Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WEINER, KURT H.;REEL/FRAME:006677/0001 Effective date: 19910912 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |