US20030094035A1 - Carbon nanotube probe tip grown on a small probe - Google Patents
Carbon nanotube probe tip grown on a small probe Download PDFInfo
- Publication number
- US20030094035A1 US20030094035A1 US10/261,084 US26108402A US2003094035A1 US 20030094035 A1 US20030094035 A1 US 20030094035A1 US 26108402 A US26108402 A US 26108402A US 2003094035 A1 US2003094035 A1 US 2003094035A1
- Authority
- US
- United States
- Prior art keywords
- nickel
- probe tip
- tip
- sidewalls
- probe
- 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
- 239000000523 sample Substances 0.000 title claims abstract description 66
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 29
- 239000002041 carbon nanotube Substances 0.000 title claims abstract description 27
- 229910021393 carbon nanotube Inorganic materials 0.000 title claims abstract description 27
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 86
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 42
- 239000002071 nanotube Substances 0.000 claims abstract description 29
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 17
- 238000005530 etching Methods 0.000 claims abstract description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 7
- 229910052742 iron Inorganic materials 0.000 claims abstract description 4
- 238000000034 method Methods 0.000 claims description 32
- 239000000463 material Substances 0.000 claims description 18
- 239000000835 fiber Substances 0.000 claims description 16
- 238000003801 milling Methods 0.000 claims description 11
- 229910052710 silicon Inorganic materials 0.000 claims description 9
- 239000010703 silicon Substances 0.000 claims description 9
- 238000005520 cutting process Methods 0.000 claims description 8
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 7
- 238000000151 deposition Methods 0.000 claims description 7
- 238000004544 sputter deposition Methods 0.000 claims description 5
- 238000010884 ion-beam technique Methods 0.000 claims description 3
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 3
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 claims description 2
- 238000000576 coating method Methods 0.000 claims description 2
- 239000002048 multi walled nanotube Substances 0.000 claims description 2
- 230000003197 catalytic effect Effects 0.000 claims 8
- 229910052814 silicon oxide Inorganic materials 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 7
- 239000002184 metal Substances 0.000 abstract description 5
- 229910052751 metal Inorganic materials 0.000 abstract description 5
- 239000013307 optical fiber Substances 0.000 abstract 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 8
- 239000003990 capacitor Substances 0.000 description 8
- 230000008021 deposition Effects 0.000 description 6
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 239000010410 layer Substances 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 241001422033 Thestylus Species 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 238000004630 atomic force microscopy Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 239000010438 granite Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000000386 microscopy Methods 0.000 description 2
- QPJSUIGXIBEQAC-UHFFFAOYSA-N n-(2,4-dichloro-5-propan-2-yloxyphenyl)acetamide Chemical compound CC(C)OC1=CC(NC(C)=O)=C(Cl)C=C1Cl QPJSUIGXIBEQAC-UHFFFAOYSA-N 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- 239000002109 single walled nanotube Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- -1 gallium ions Chemical class 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 229910052594 sapphire Inorganic materials 0.000 description 1
- 239000010980 sapphire Substances 0.000 description 1
- 238000004621 scanning probe microscopy Methods 0.000 description 1
- 238000004574 scanning tunneling microscopy Methods 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid group Chemical class S(O)(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
- G01Q70/00—General aspects of SPM probes, their manufacture or their related instrumentation, insofar as they are not specially adapted to a single SPM technique covered by group G01Q60/00
- G01Q70/08—Probe characteristics
- G01Q70/10—Shape or taper
- G01Q70/12—Nanotube tips
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/158—Carbon nanotubes
- C01B32/16—Preparation
- C01B32/162—Preparation characterised by catalysts
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2202/00—Structure or properties of carbon nanotubes
- C01B2202/20—Nanotubes characterized by their properties
- C01B2202/36—Diameter
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S977/00—Nanotechnology
- Y10S977/84—Manufacture, treatment, or detection of nanostructure
- Y10S977/849—Manufacture, treatment, or detection of nanostructure with scanning probe
- Y10S977/855—Manufacture, treatment, or detection of nanostructure with scanning probe for manufacture of nanostructure
- Y10S977/856—Manufacture, treatment, or detection of nanostructure with scanning probe for manufacture of nanostructure including etching/cutting
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S977/00—Nanotechnology
- Y10S977/84—Manufacture, treatment, or detection of nanostructure
- Y10S977/849—Manufacture, treatment, or detection of nanostructure with scanning probe
- Y10S977/86—Scanning probe structure
- Y10S977/863—Atomic force probe
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S977/00—Nanotechnology
- Y10S977/84—Manufacture, treatment, or detection of nanostructure
- Y10S977/849—Manufacture, treatment, or detection of nanostructure with scanning probe
- Y10S977/86—Scanning probe structure
- Y10S977/875—Scanning probe structure with tip detail
- Y10S977/876—Nanotube tip
Definitions
- the invention relates generally to mechanical probe tips such as those used in atomic force microscopy.
- the invention relates to a carbon nanotube grown directly on a pointed end of a probe.
- Atomic force microscopes have been recently developed for mechanically profiling small features, for example, determining critical dimensions (CDs) of via holes in semiconductor integrated circuits. Such holes have depths of about 1 ⁇ m and widths which are being pushed to 180 nm and below.
- an exceedingly fine probe tip is disposed on the end of a cantilever overlying the feature. In the pixel mode of operation, the probe tip is successively positioned at points on a line above and traversing the feature being probed. The cantilever lowers the probe tip until it encounters the surface, and both the horizontal position and the vertical position at which the probe meets the surface are recorded. A series of such measurements provide the desired microscopic profile.
- Stylus Nanoprobe SNP available from Surface/Interface, Inc. of Sunnyvale, Calif. It employs technology similar to the rocking balanced beam probe disclosed by Griffith et al. in U.S. Pat. No. 5,307,693 and by Bryson et al. in U.S. Pat. No. 5,756,887.
- FIG. 1 Such a tool is schematically illustrated in the side view of FIG. 1.
- a wafer 10 or other sample to be is supported on a support surface 12 supported successively on a tilt stage 14 , an x-slide 16 , and a y-slide 18 , all of which are movable along their respective axes so as to provide horizontal two-dimensional and tilt control of the wafer 10 .
- these mechanical stages provide a relatively great range of motion, their resolutions are relatively coarse compared to the resolution sought in the probing.
- the bottom y-slide 18 rests on a heavy granite slab 20 providing vibrational stability.
- a gantry 22 is supported on the granite slab 20 .
- a probe head 24 hangs in the vertical z-direction from the gantry 22 through an intermediate piezoelectric actuator 26 providing about 10 ⁇ m of motion in (x, y, z) by voltages applied across electrodes attached to the walls of a piezoelectric tube.
- a probe assembly with a tiny attached probe tip 28 projects downwardly from the probe head 24 to selectively engage the probe tip 28 with the top surface of the wafer 10 and to thereby determine its vertical and horizontal dimensions.
- a dielectric support 30 fixed to the bottom of the piezoelectric actuator 26 includes on its top side, with respect to the view of FIG. 1, a magnet 32 .
- On the bottom of the dielectric support 30 are deposited two isolated capacitor plates 34 , 36 and two interconnected contact pads 38 .
- a beam 40 is medially fixed on its two lateral sides and is also electrically connected to two metallic and ferromagnetic ball bearings 42 .
- the beam 40 is preferably composed of heavily doped silicon so as to be electrically conductive, and a thin silver layer is deposited on it to make good electrical contacts to the ball bearings.
- the two ball bearings 42 are placed on respective ones of the two contact pads 38 and generally between the capacitor plates 34 , 36 , and the magnet 32 holds the ferromagnetic bearings 42 and the attached beam 40 to the dielectric support 30 .
- the attached beam 40 is held in a position generally parallel to the dielectric support 40 with a balanced vertical gap 46 of about 25 ⁇ m between the capacitor plates 34 , 36 and the beam 40 .
- the beam 40 holds on its distal end a glass tab 48 to which is fixed a stylus 50 having the probe tip 52 projecting downwardly to selectively engage the top of the wafer 10 being probed.
- Two capacitors are formed between the respective capacitor plates 34 , 36 and the conductive beam 40 .
- the capacitor plates 34 , 36 and the two contact pads 38 commonly electrically connected to the conductive beam 40 , are separately connected by three unillustrated electrical lines to three terminals of external measurement and control circuitry
- This servo system both measures the two capacitances and applies differential voltage to the two capacitor plates 34 , 36 to keep them in the balanced position.
- the piezoelectric actuator 26 lowers the stylus 50 to the point that it encounters the feature being probed, the beam 40 rocks upon contact of the probe tip 52 with the wafer 10 .
- the difference in capacitance between the plates 34 , 36 is detected, and the servo circuit attempts to rebalance the beam 40 by applying different voltages across the two capacitors, which amounts to a net force that the stylus 50 is applying to the wafer 10 .
- the vertical position of the piezoelectric actuator 26 is used as an indication of the depth or height of the feature.
- This and other types of AFMs have control and sensing elements more than adequate for the degree of precision for profiling a 1180 nm ⁇ 1 ⁇ m hole.
- the probe tip presents a challenge for profiling the highly anisotropic holes desired in semiconductor fabrication as well as for other uses such as measuring DNA strands and the like.
- the probe tip needs to be long, narrow, and stiff. Its length needs to at least equal the depth of the hole being probed, and its width throughout this length needs to be less than the width of the hole.
- a fairly stiff probe tip reduces the biasing introduced by probe tips being deflected by a sloping surface.
- One popular type of probe tip is a shaped silica tip, such as disclosed by Marchman in U.S. Pat. Nos. 5,395,741 and 5,480,049 and by Filas and Marchman in U.S. Pat. No. 5,703,979.
- a thin silica fiber has its end projecting downwardly into an etching solution. The etching forms a tapered portion near the surface of the fiber, and, with careful timing, the deeper portion of the fiber is etched to a cylinder of a much smaller diameter.
- the tip manufacturing is relatively straightforward, and the larger fiber away from the tip provides good mechanical support for the small tip. However, it is difficult to obtain the more desirable cylindrical probe tip by the progressive etching method rather than the tapered portion alone.
- silica is relatively soft so that its lifetime is limited because it is continually being forced against a relatively hard substrate.
- One promising technology for AFM probe tips involves carbon nanotubes which can be made to spontaneously grow normal to a surface of an insulator such as glass covered with a thin layer of a catalyzing metal such as nickel. Carbon nanotubes can be grown to diameters ranging down to 5 to 20 nm and with lengths of significantly more than 1 ⁇ m. Nanotubes can form as single-wall nanotubes or as multiple-wall nanotubes.
- a single wall is an cylindrically shaped atomically thin sheet of carbon atoms arranged in an hexagonal crystalline structure with a graphitic type of bonding. Multiple walls bond to each other with a tetrahedral bonding structure, which is exceedingly robust.
- nanotubes offer a very stiff and very narrow probe tip well suited for atomic force. microscopy.
- carbon nanotubes are electrically conductive so that they are well suited for scanning tunneling microscopy and other forms of probing relying upon passing a current through the probe tip. Dai et al. describe the manual fabrication of a nanotube probe tip in “Nanotubes as nanoprobes in scanning probe microscopy,” Nature , vol. 384, 14 November 1996, pp. 147-150.
- nanotubes suffer from the disadvantage that a large number of them simultaneously form on a surface producing either a tangle or a forest of such tubes, as is clearly illustrated by Ren et al. in “Synthesis of large arrays of well-aligned carbon nanotubes on glass,” Science , vol. 282, 6 November 1998, pp. 1105-1107. The task then remains to affix one nanotube to a somewhat small probe tip support.
- Dai et al. disclose an assembly method in which they coat the apex of a silicon pyramid at the probe end with adhesive. The coated silicon tip was then brushed against a bundle of nanotubes, and a single nanotube can be pulled from the bundle.
- Ren et al. describe a method of growing isolated nanotubes in “Growth of a single freestanding multiwall carbon nanotube on each nanonickel dot,” Applied Physics Letters , vol. 75, no. 8, 23 August 1999, pp. 1086-1088. They deposit 15 nm of nickel on silicon and pattern it into a grid of nickel dots having sizes of somewhat more than 100 nm. Plasma-enhanced chemical vapor deposition using acetylene and ammonia produces a single nanotube on each dot having an obelisk shape with a base diameter of about 150 nm and a sharpened tip.
- Ren et al. do not address the difficult problem of transferring such a nanotube, which they describe as being tightly bonded to the nickel, from the nickel-plated substrate to a probe end.
- Cheung et al. disclose another method of growing isolated nanotubes in “Carbon nanotube atomic force microscopy tips: Direct growth by chemical vapor deposition and appliaction to high-resolution imaging,” Proceedings of the National Academy of Sciences , vol. 97, no. 8, 11 April 2000, pp. 3809-3813. They etch aniostropic holes in a silicon tip and deposit the catalyzing iron or iron oxide in the bottom of the holes. The carbon nanotubes grow out of the holes.
- growth in such restricted geometries is considered to be disadvantageous and to favor single-wall rather than multiple-wall nanotubes. Further, this method provides only limited control over the number and size of the nanotubes being grown.
- a probe end is shaped to have sloping sides and a generally flat end, that is, in the shape of sloping mesa.
- the diameter of the mesa top is preferably in the range of 20 to 300 nm.
- Nickel or other material that catalyzes the growth of carbon nanotubes is directionally deposited onto the probe end. Because of the geometry, the thickness of the deposited nickel, as measured from the underlying surface, is greater on the mesa top than on the mesa sides.
- the nickel is then isotropically etched for a time sufficient to remove the nickel from the mesa sides but to leave sufficient nickel on the mesa top to catalyze the growth of a single carbon nanotube.
- the nanotube grows with a bottom diameter approximately equal to that of the nickel dot on top of the mesa.
- FIG. 1 is a schematic elevational view of a rocking beam atomic force microscope.
- FIG. 2 is a cross-sectional side view of a portion of the atomic force microscope of FIG. 1.
- FIG. 3 is a cross-sectional side view of a probe end having a tapered tip and available in the prior art, the figure including an exploded view of the sharp probe end.
- FIG. 4 is a cross-sectional view showing the position of a sectioning of the probe end of FIG. 2.
- FIG. 5 is a cross-sectional view showing the sectioned probe end.
- FIG. 6 is a cross-sectional view showing the directional deposition of nickel or other catalyzing material.
- FIG. 7 is a cross-sectional view showing a nickel dot formed only on the sectioned end of the probe end.
- FIG. 8 is a cross-sectional view showing a nanotube grown on the nickel dot.
- FIG. 9 is a cross-sectional view showing a second embodiment of the invention.
- the invention allows the fabrication of a single carbon nanotube on a narrow support structure well suited for easy attachment to a probe of an atomic force microscope (AFM) or other type of microprobe.
- AFM atomic force microscope
- a support structure 60 illustrated in side view in FIG. 3, is formed having a relatively massive upper portion 62 and a shaped tip 64 with a sharp point 66 having a curvature of less than about 50 nm. On the scale of probe tips, the upper portion 62 and the shaped tip 64 have a common longitudinal axis.
- the support structure 60 is illustrated with the orientation of its intended final use in a microscope overlying a sample being probed.
- the support structure 60 may be the quartz (silica) fiber of Marchman in which the shaped tip 64 is formed by placing an end of a 125 ⁇ m fiber in a bath of hydrofluoric acid (HF) overlaid by a layer of oil and leaving it in that position for a sufficiently long period that the fiber end is etched to a point. That is, the etching continues to completely etch away the cylinder of the Marchman tip. The point at which the HF completely dissolves the fiber defines the sharp point 66 .
- the shaped tip can be defined by polishing and grinding, particularly for sapphire fiber.
- the shaped tip 64 need not have a strictly conical shape, but it is advantageous that there be an sloping portion between the sharp point 66 and the relatively massive fiber 62 to provide mechanical stability in the finally assembled probe.
- the support structure 60 is then subjected to focused ion beam (FIB) milling along a line 68 , illustrated in the cross-sectional view of FIG. 4, that in this embodiment is transverse to the axis of the support structure and passes through a predetermined width of the shaped tip 64 .
- the predetermined width closely corresponds to the width of the final carbon nanotube and may be, for example, 100 nm.
- FIB milling is a well known technique for micromicromaching and relies upon a focused beam typically of gallium ions to mill structures with a resolution down to about 5 nm.
- Such a system is the FIB 200TEM available from FEI Company of Hillsboro, Oreg. Other milling techniques could be used, but FIB milling is effective and economical.
- the milling produces a shaped tip 64 ′, illustrated in the cross-sectional view of FIG. 5, having a flat end 70 and sloping sidewalls 72 .
- a film 76 of nickel or other catalyzing metal is then directionally deposited onto the probe tip 64 ′, preferably by sputtering metal atoms along the longitudinal axis of the shaped tip 64 ′.
- the thickness of the deposition, as measured along the longitudinal axis, is substantially constant between the area of the flat end 70 and the sloping sidewalls 72 of the shaped tip 64 ′.
- the thickness as measured at a perpendicular to the underlying surface, is substantially thicker in the area overlying the flat 70 than in the areas overlying the sloping sidewalls 72 .
- the sputtering may be performed in an ion sputtering system using a nickel target. Such a system is the Model 681 High Resolution Ion Coater from Gatan of Pleasanton, Calif. Other types of deposition are possible, such as molecular beam techniques usually associated with molecular beam epitaxy.
- the nickel-plated shaped tip 64 ′ is subjected to isotropic etching of the nickel for a time just sufficient to remove the nickel from the tip sidewalls 72 but leaving a nickel dot 80 over the tip end 70 .
- a minimum thickness of approximately 15 to 20, preferably 30 to 40 nm, of nickel is desired in the area of the nickel dot 80 to catalyze the nanotube growth.
- the etching time obviously needs to be controlled so that it continues long enough to remove the sidewall nickel while leaving sufficient of the end nickel.
- nickel will typically have an oxidized surface layer upon any exposure to air.
- Any number of isotropic wet etchants for nickel and nickel oxide are known, as tabulated in CRC Handbook of Metal Etchants , eds. Walker et al., CRC Press, 1991, pp. 857-875 and include dilute nitric and sulfuric acids for nickel and ammonium hydroxide for nickel oxide.
- the nickel dot 80 provides a small catalyzing area for the growth of a single carbon nanotube 84 illustrated in cross-sectional view in FIG. 8. Ren et al. and Cheung et al. describe the process for selective growth of nanotubes in the above cited references.
- the diameter of the nanotube 34 corresponds generally to the diameter or average lateral extent of the flattened end 70 of the shaped tip 64 ′. For a non-circular end 80 , the nanotube diameter is approximately equal to the minimum lateral extent of the end.
- the probe structure illustrated in FIG. 8 includes a relatively rugged support structure 62 , illustrated in FIG. 3, which is ready to be mounted onto the probe of the AFM or other microscope using a stylus.
- the method described above requires that the sidewalls of the shaped tip slope away from the tip end.
- the slope is preferably at least 60° from the plane.
- the differential coating works even with a slope of 90°, that is, vertical sidewalls.
- Such a shape may be produced by FIB milling, for example, a cylinder having a diameter of 100 nm or a similarly sized rectangular post into the tip 66 at the end of the conical tip 64 prior to nickel deposition.
- a shaped tip 64 ′′ is formed by milling the conical tip 64 to have an inclined flat end 70 ′. That is, the flat end 70 ′ is not perpendicular to the axis of the fiber or the shaped tip 64 ′′.
- the deposition of the nickel 80 and the growth of the carbon nanotube 84 are then performed as described above. This configuration is particularly useful for probing very narrow features at the bottom edges of somewhat wider holes, for example, punch through occurring at the corner of a narrow trench, which occurs in semiconductor processing.
- the above description includes a support structure formed from a quartz fiber
- a thin layer of silicon nitride is coated on the silicon pyramid. After cutting, a square end surface is formed.
- the underlying silicon is very easily mounted to the AFM probe. Cheung et al. describe a method of cutting a flat surface at the pyramid apex by dragging the pyramid across a hard surface. Such a surface may not be completely flat but most probably deviates by less than 10° from a planar surface.
- the support structure may be composed of other materials.
- Nickel is not the only possible material for catalyzing nanotube growth. Iron and iron oxide have been used. Cobalt has been suggested as a catalyst. All these catalyzing materials can be used with the process described above.
- the carbon nanotubes produced according to the invention are grown on substantially planar and well defined areas of nickel or other catalyzing material. Thereby, the tip diameter and orientation are well controlled. Carbon nanotube tips have the well known characteristics of high stiffness and toughness to wear under continued use.
Abstract
A method of fabricating a carbon nanotube probe tip and the resultant probe tip, particularly for use in an atomic force microscope. A moderately sharply peaked support structure has its tip cut or flattened to have a substantially flat end of size of about 20 to 200 nm across. The support structure may be formed by etching a conical end into a silica optical fiber. Nickel or other catalyzing metal such as iron is directionally sputtered onto the flat end and the sloped sidewalls of the support structure. The nickel is anisotropically etched to remove all the nickel from the sidewalls but leaving at least 15 nm on the flat end to form a small nickel dot. A carbon nanotube is then grown with the nickel catalyzing its growth such that only a single nanotube forms on the nickel dot and its diameter conforms to the size of the nickel dot.
Description
- The invention relates generally to mechanical probe tips such as those used in atomic force microscopy. In particular, the invention relates to a carbon nanotube grown directly on a pointed end of a probe.
- Atomic force microscopes (AFMs) have been recently developed for mechanically profiling small features, for example, determining critical dimensions (CDs) of via holes in semiconductor integrated circuits. Such holes have depths of about 1 μm and widths which are being pushed to 180 nm and below. For detailed measurement of the feature, an exceedingly fine probe tip is disposed on the end of a cantilever overlying the feature. In the pixel mode of operation, the probe tip is successively positioned at points on a line above and traversing the feature being probed. The cantilever lowers the probe tip until it encounters the surface, and both the horizontal position and the vertical position at which the probe meets the surface are recorded. A series of such measurements provide the desired microscopic profile. An example of such an atomic force microscope is the Stylus Nanoprobe SNP available from Surface/Interface, Inc. of Sunnyvale, Calif. It employs technology similar to the rocking balanced beam probe disclosed by Griffith et al. in U.S. Pat. No. 5,307,693 and by Bryson et al. in U.S. Pat. No. 5,756,887.
- Such a tool is schematically illustrated in the side view of FIG. 1. A few more details are found in U.S. patent application Ser. No. 09/354,528, filed Jul. 15, 1999 and incorporated herein by reference in its entirety. A
wafer 10 or other sample to be is supported on asupport surface 12 supported successively on a tilt stage 14, an x-slide 16, and a y-slide 18, all of which are movable along their respective axes so as to provide horizontal two-dimensional and tilt control of thewafer 10. Although these mechanical stages provide a relatively great range of motion, their resolutions are relatively coarse compared to the resolution sought in the probing. The bottom y-slide 18 rests on aheavy granite slab 20 providing vibrational stability. Agantry 22 is supported on thegranite slab 20. Aprobe head 24 hangs in the vertical z-direction from thegantry 22 through an intermediatepiezoelectric actuator 26 providing about 10 μm of motion in (x, y, z) by voltages applied across electrodes attached to the walls of a piezoelectric tube. A probe assembly with a tiny attachedprobe tip 28 projects downwardly from theprobe head 24 to selectively engage theprobe tip 28 with the top surface of thewafer 10 and to thereby determine its vertical and horizontal dimensions. - Principal parts of the
probe head 24 of FIG. 2 are illustrated in the side view of FIG. 2. Adielectric support 30 fixed to the bottom of thepiezoelectric actuator 26 includes on its top side, with respect to the view of FIG. 1, amagnet 32. On the bottom of thedielectric support 30 are deposited two isolatedcapacitor plates 34, 36 and two interconnectedcontact pads 38. - A
beam 40 is medially fixed on its two lateral sides and is also electrically connected to two metallic andferromagnetic ball bearings 42. Thebeam 40 is preferably composed of heavily doped silicon so as to be electrically conductive, and a thin silver layer is deposited on it to make good electrical contacts to the ball bearings. The twoball bearings 42 are placed on respective ones of the twocontact pads 38 and generally between thecapacitor plates 34, 36, and themagnet 32 holds theferromagnetic bearings 42 and the attachedbeam 40 to thedielectric support 30. The attachedbeam 40 is held in a position generally parallel to thedielectric support 40 with a balancedvertical gap 46 of about 25 μm between thecapacitor plates 34, 36 and thebeam 40. Unbalancing of the vertical gap allows a rocking motion of about 25 μm. Thebeam 40 holds on its distal end aglass tab 48 to which is fixed astylus 50 having the probe tip 52 projecting downwardly to selectively engage the top of thewafer 10 being probed. - Two capacitors are formed between the
respective capacitor plates 34, 36 and theconductive beam 40. Thecapacitor plates 34, 36 and the twocontact pads 38, commonly electrically connected to theconductive beam 40, are separately connected by three unillustrated electrical lines to three terminals of external measurement and control circuitry This servo system both measures the two capacitances and applies differential voltage to the twocapacitor plates 34, 36 to keep them in the balanced position. When thepiezoelectric actuator 26 lowers thestylus 50 to the point that it encounters the feature being probed, thebeam 40 rocks upon contact of the probe tip 52 with thewafer 10. The difference in capacitance between theplates 34, 36 is detected, and the servo circuit attempts to rebalance thebeam 40 by applying different voltages across the two capacitors, which amounts to a net force that thestylus 50 is applying to thewafer 10. When the force exceeds a threshold, the vertical position of thepiezoelectric actuator 26 is used as an indication of the depth or height of the feature. - This and other types of AFMs have control and sensing elements more than adequate for the degree of precision for profiling a 1180 nm×1 μm hole. However, the probe tip presents a challenge for profiling the highly anisotropic holes desired in semiconductor fabrication as well as for other uses such as measuring DNA strands and the like. The probe tip needs to be long, narrow, and stiff. Its length needs to at least equal the depth of the hole being probed, and its width throughout this length needs to be less than the width of the hole. A fairly stiff probe tip reduces the biasing introduced by probe tips being deflected by a sloping surface.
- One popular type of probe tip is a shaped silica tip, such as disclosed by Marchman in U.S. Pat. Nos. 5,395,741 and 5,480,049 and by Filas and Marchman in U.S. Pat. No. 5,703,979. A thin silica fiber has its end projecting downwardly into an etching solution. The etching forms a tapered portion near the surface of the fiber, and, with careful timing, the deeper portion of the fiber is etched to a cylinder of a much smaller diameter. The tip manufacturing is relatively straightforward, and the larger fiber away from the tip provides good mechanical support for the small tip. However, it is difficult to obtain the more desirable cylindrical probe tip by the progressive etching method rather than the tapered portion alone. Furthermore, silica is relatively soft so that its lifetime is limited because it is continually being forced against a relatively hard substrate.
- One promising technology for AFM probe tips involves carbon nanotubes which can be made to spontaneously grow normal to a surface of an insulator such as glass covered with a thin layer of a catalyzing metal such as nickel. Carbon nanotubes can be grown to diameters ranging down to 5 to 20 nm and with lengths of significantly more than 1 μm. Nanotubes can form as single-wall nanotubes or as multiple-wall nanotubes. A single wall is an cylindrically shaped atomically thin sheet of carbon atoms arranged in an hexagonal crystalline structure with a graphitic type of bonding. Multiple walls bond to each other with a tetrahedral bonding structure, which is exceedingly robust. The modulus of elasticity for carbon nanotubes is significantly greater than that for silica. Thus, nanotubes offer a very stiff and very narrow probe tip well suited for atomic force. microscopy. Furthermore, carbon nanotubes are electrically conductive so that they are well suited for scanning tunneling microscopy and other forms of probing relying upon passing a current through the probe tip. Dai et al. describe the manual fabrication of a nanotube probe tip in “Nanotubes as nanoprobes in scanning probe microscopy,”Nature, vol. 384, 14 November 1996, pp. 147-150.
- Typically, nanotubes suffer from the disadvantage that a large number of them simultaneously form on a surface producing either a tangle or a forest of such tubes, as is clearly illustrated by Ren et al. in “Synthesis of large arrays of well-aligned carbon nanotubes on glass,”Science, vol. 282, 6 November 1998, pp. 1105-1107. The task then remains to affix one nanotube to a somewhat small probe tip support. Dai et al. disclose an assembly method in which they coat the apex of a silicon pyramid at the probe end with adhesive. The coated silicon tip was then brushed against a bundle of nanotubes, and a single nanotube can be pulled from the bundle. This method is nonetheless considered expensive and tedious requiring both optical and electron microscopes. Additionally, there is little control over the final orientation of the nanotube, certainly not to the precision needed to analyze semiconductor features. Cheung et al. describe another method of growing and transferring nanotubes in “Growth and fabrication with single-walled carbon nanotube probe microscopy tips,” Applied Physics Letters, vol. 76, no. 21, 22 May 2000, pp. 3136-3138. However, they either produce poor directional control with a very narrow, single nanotube or require a complex transfer mechanism with nanotube bundles.
- Ren et al. describe a method of growing isolated nanotubes in “Growth of a single freestanding multiwall carbon nanotube on each nanonickel dot,”Applied Physics Letters, vol. 75, no. 8, 23 August 1999, pp. 1086-1088. They deposit 15 nm of nickel on silicon and pattern it into a grid of nickel dots having sizes of somewhat more than 100 nm. Plasma-enhanced chemical vapor deposition using acetylene and ammonia produces a single nanotube on each dot having an obelisk shape with a base diameter of about 150 nm and a sharpened tip. However, Ren et al. do not address the difficult problem of transferring such a nanotube, which they describe as being tightly bonded to the nickel, from the nickel-plated substrate to a probe end.
- Cheung et al. disclose another method of growing isolated nanotubes in “Carbon nanotube atomic force microscopy tips: Direct growth by chemical vapor deposition and appliaction to high-resolution imaging,”Proceedings of the National Academy of Sciences, vol. 97, no. 8, 11 April 2000, pp. 3809-3813. They etch aniostropic holes in a silicon tip and deposit the catalyzing iron or iron oxide in the bottom of the holes. The carbon nanotubes grow out of the holes. However, growth in such restricted geometries is considered to be disadvantageous and to favor single-wall rather than multiple-wall nanotubes. Further, this method provides only limited control over the number and size of the nanotubes being grown.
- Accordingly, a more efficient method is desired for forming a probe tip having a single carbon nanotube. Furthermore, the structure of the probe end and probe tip should facilitate assembly of the probe and contribute to its robustness.
- A probe end is shaped to have sloping sides and a generally flat end, that is, in the shape of sloping mesa. The diameter of the mesa top is preferably in the range of 20 to 300 nm. Nickel or other material that catalyzes the growth of carbon nanotubes is directionally deposited onto the probe end. Because of the geometry, the thickness of the deposited nickel, as measured from the underlying surface, is greater on the mesa top than on the mesa sides. The nickel is then isotropically etched for a time sufficient to remove the nickel from the mesa sides but to leave sufficient nickel on the mesa top to catalyze the growth of a single carbon nanotube. Typically, the nanotube grows with a bottom diameter approximately equal to that of the nickel dot on top of the mesa.
- FIG. 1 is a schematic elevational view of a rocking beam atomic force microscope.
- FIG. 2 is a cross-sectional side view of a portion of the atomic force microscope of FIG. 1.
- FIG. 3 is a cross-sectional side view of a probe end having a tapered tip and available in the prior art, the figure including an exploded view of the sharp probe end.
- FIG. 4 is a cross-sectional view showing the position of a sectioning of the probe end of FIG. 2.
- FIG. 5 is a cross-sectional view showing the sectioned probe end.
- FIG. 6 is a cross-sectional view showing the directional deposition of nickel or other catalyzing material.
- FIG. 7 is a cross-sectional view showing a nickel dot formed only on the sectioned end of the probe end.
- FIG. 8 is a cross-sectional view showing a nanotube grown on the nickel dot.
- FIG. 9 is a cross-sectional view showing a second embodiment of the invention.
- The invention allows the fabrication of a single carbon nanotube on a narrow support structure well suited for easy attachment to a probe of an atomic force microscope (AFM) or other type of microprobe.
- A
support structure 60, illustrated in side view in FIG. 3, is formed having a relatively massiveupper portion 62 and a shapedtip 64 with asharp point 66 having a curvature of less than about 50 nm. On the scale of probe tips, theupper portion 62 and the shapedtip 64 have a common longitudinal axis. Thesupport structure 60 is illustrated with the orientation of its intended final use in a microscope overlying a sample being probed. Thesupport structure 60 may be the quartz (silica) fiber of Marchman in which the shapedtip 64 is formed by placing an end of a 125 μm fiber in a bath of hydrofluoric acid (HF) overlaid by a layer of oil and leaving it in that position for a sufficiently long period that the fiber end is etched to a point. That is, the etching continues to completely etch away the cylinder of the Marchman tip. The point at which the HF completely dissolves the fiber defines thesharp point 66. Alternatively, the shaped tip can be defined by polishing and grinding, particularly for sapphire fiber. The shapedtip 64 need not have a strictly conical shape, but it is advantageous that there be an sloping portion between thesharp point 66 and the relativelymassive fiber 62 to provide mechanical stability in the finally assembled probe. - The
support structure 60 is then subjected to focused ion beam (FIB) milling along aline 68, illustrated in the cross-sectional view of FIG. 4, that in this embodiment is transverse to the axis of the support structure and passes through a predetermined width of the shapedtip 64. The predetermined width closely corresponds to the width of the final carbon nanotube and may be, for example, 100 nm. FIB milling is a well known technique for micromicromaching and relies upon a focused beam typically of gallium ions to mill structures with a resolution down to about 5 nm. Such a system is the FIB 200TEM available from FEI Company of Hillsboro, Oreg. Other milling techniques could be used, but FIB milling is effective and economical. - The milling produces a shaped
tip 64′, illustrated in the cross-sectional view of FIG. 5, having aflat end 70 and slopingsidewalls 72. Then, as illustrated in the cross-sectional view of FIG. 6, afilm 76 of nickel or other catalyzing metal is then directionally deposited onto theprobe tip 64′, preferably by sputtering metal atoms along the longitudinal axis of the shapedtip 64′. The thickness of the deposition, as measured along the longitudinal axis, is substantially constant between the area of theflat end 70 and the slopingsidewalls 72 of the shapedtip 64′. However, the thickness, as measured at a perpendicular to the underlying surface, is substantially thicker in the area overlying the flat 70 than in the areas overlying the slopingsidewalls 72. The effect is primarily geometric. If the probe tip has a tip angle 2θ and the deposition is totally aniostropic, then the sidewall thickness is sinθ times the end thickness. For example, if 2θ=31.3°, then the sidewall thickness is 27% of the end thickness. The sputtering may be performed in an ion sputtering system using a nickel target. Such a system is the Model 681 High Resolution Ion Coater from Gatan of Pleasanton, Calif. Other types of deposition are possible, such as molecular beam techniques usually associated with molecular beam epitaxy. - As illustrated in the cross-sectional view of FIG. 7, the nickel-plated
shaped tip 64′ is subjected to isotropic etching of the nickel for a time just sufficient to remove the nickel from the tip sidewalls 72 but leaving anickel dot 80 over thetip end 70. A minimum thickness of approximately 15 to 20, preferably 30 to 40 nm, of nickel is desired in the area of thenickel dot 80 to catalyze the nanotube growth. Assuming the lower value of 15 nm and a tip angle 2θ of 31.3°, about 27 nm of nickel needs to be anisotropically deposited over the area of thetip end 70 to account for the end nickel being thinned during removal of the sidewall nickel, which has an initial thickness of 7 nm. The etching time obviously needs to be controlled so that it continues long enough to remove the sidewall nickel while leaving sufficient of the end nickel. - It may be advantageous to oxidize the nickel prior to etching, and in any case nickel will typically have an oxidized surface layer upon any exposure to air. Any number of isotropic wet etchants for nickel and nickel oxide are known, as tabulated inCRC Handbook of Metal Etchants, eds. Walker et al., CRC Press, 1991, pp. 857-875 and include dilute nitric and sulfuric acids for nickel and ammonium hydroxide for nickel oxide.
- The
nickel dot 80 provides a small catalyzing area for the growth of asingle carbon nanotube 84 illustrated in cross-sectional view in FIG. 8. Ren et al. and Cheung et al. describe the process for selective growth of nanotubes in the above cited references. The diameter of thenanotube 34 corresponds generally to the diameter or average lateral extent of the flattenedend 70 of the shapedtip 64′. For anon-circular end 80, the nanotube diameter is approximately equal to the minimum lateral extent of the end. - It has proven difficult to control the length to which nanotubes grow. Accordingly, it may be necessary to perform an additional step of cutting the carbon nanotube to a prescribed length, for example, by FIB milling.
- The probe structure illustrated in FIG. 8 includes a relatively
rugged support structure 62, illustrated in FIG. 3, which is ready to be mounted onto the probe of the AFM or other microscope using a stylus. - The method described above requires that the sidewalls of the shaped tip slope away from the tip end. To achieve the required differential but isotropic etching, the slope is preferably at least 60° from the plane. The differential coating works even with a slope of 90°, that is, vertical sidewalls. Such a shape may be produced by FIB milling, for example, a cylinder having a diameter of 100 nm or a similarly sized rectangular post into the
tip 66 at the end of theconical tip 64 prior to nickel deposition. - The embodiment described above produces a carbon nanotube extending along the axis of the conical tip. However, in another embodiment illustrated in the cross-sectional view of FIG. 9, a shaped
tip 64″ is formed by milling theconical tip 64 to have an inclinedflat end 70′. That is, theflat end 70′ is not perpendicular to the axis of the fiber or the shapedtip 64″. The deposition of thenickel 80 and the growth of thecarbon nanotube 84 are then performed as described above. This configuration is particularly useful for probing very narrow features at the bottom edges of somewhat wider holes, for example, punch through occurring at the corner of a narrow trench, which occurs in semiconductor processing. - Although the above description includes a support structure formed from a quartz fiber, it is known that the preferential etching of <111> planes of <001>-oriented silicon can form pyramids having an apex angle of 2θ=70.5°, which is equivalent to a slope of 54.74° from the plane. Often a thin layer of silicon nitride is coated on the silicon pyramid. After cutting, a square end surface is formed. The underlying silicon is very easily mounted to the AFM probe. Cheung et al. describe a method of cutting a flat surface at the pyramid apex by dragging the pyramid across a hard surface. Such a surface may not be completely flat but most probably deviates by less than 10° from a planar surface. The support structure may be composed of other materials.
- Nickel is not the only possible material for catalyzing nanotube growth. Iron and iron oxide have been used. Cobalt has been suggested as a catalyst. All these catalyzing materials can be used with the process described above.
- None of the steps described above are particularly difficult or problematic. FIB milling has been shown to be easily and reliably performed. Thereby, probe tips produced according to the invention are relatively economical. Further, the sputter coating and isotropic etching can be simultaneously performed upon a large number of probe tips mounted on a common tip holder, thereby further improving the efficiency of the fabrication method of the invention.
- The carbon nanotubes produced according to the invention are grown on substantially planar and well defined areas of nickel or other catalyzing material. Thereby, the tip diameter and orientation are well controlled. Carbon nanotube tips have the well known characteristics of high stiffness and toughness to wear under continued use.
Claims (23)
1. A method of forming a probe tip, comprising the steps of:
providing a member comprising a shaped tip having sidewalls and extending along an axis;
cutting a flat surface in said shaped tip;
anisotropically depositing a catalytic material onto said flat surface and onto said sloping sidewalls;
directionally etching said catalytic material to remove said catalytic material from said sidewalls while leaving a thickness of said catalytic material on said flat surface; and
growing a carbon nanotube on a portion of said catalytic material remaining on said flat surface in a process catalyzed by said catalytic material.
2. The method of claim 1 , wherein said flat surface has a minimum lateral size of between 15 and 300 nm.
3. The method of claim 1 , wherein said catalytic material comprises nickel.
4. The method of claim 1 , wherein said catalytic material comprises iron.
5. The method of claim 1 , wherein said member comprises silicon oxide.
6. The method of claim 1 , wherein said member is formed from silica fiber.
7. The method of claim 6 , wherein said member has said ends formed into said fiber and said sidewalls slope from an axis of said fiber.
8. The method of claim 6 , wherein said planar end is cut to be non-perpendicular to an axis of said fiber.
9. The method of claim 1 , wherein said cutting step cuts said sidewalls into said member to be parallel to each other.
10. The method of claim 1 , wherein said member comprises silicon.
11. The method of claim 1 , wherein said shaped tip has a pyramidal shape.
12. The method of claim 1 , wherein said anisotropic coating step comprises sputtering.
13. The method of claim 1 , wherein said cutting step comprises focused ion beam milling.
14. The method of claim 1 , further comprising cutting said carbon nanotube to reduce its length.
15. The method of claim 14 , wherein said cutting said carbon nanotube comprises focused ion beam milling.
16. A probe tip, comprising:
a support including a shaped tip having a planar end of minimum lateral extent of between 15 and 300 nm and sidewalls sloping from said planar end;
a catalyzing layer of material capable of catalyzing growth of carbon nanotubes formed on said planar end but not on said sidewalls; and
a single carbon nanotube formed on said catalyzing layer.
17. The probe tip of claim 16 , wherein said nanotube is a multi-wall nanotube.
18. The probe tip of claim 16 , wherein said material comprises metallic nickel.
19. The probe tip of claim 15 , wherein said material comprises nickel oxide.
20. The probe tip of claim 15 , wherein said material comprises metallic iron or iron oxide.
21. The probe tip of claim 15 , wherein said sidewalls slope from said planar end by between 60° and 90°.
22. The probe tip of claim 15 , wherein said catalyzing layer has a thickness of at least 15 nm.
23. An atomic force microscope including the probe tip of claim 15 and a vertical actuator, wherein said actuator causes said probe tip to encounter a surface being probed.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/261,084 US20030094035A1 (en) | 2000-09-08 | 2002-09-30 | Carbon nanotube probe tip grown on a small probe |
US10/763,061 US7032437B2 (en) | 2000-09-08 | 2004-01-22 | Directed growth of nanotubes on a catalyst |
US11/387,561 US7258901B1 (en) | 2000-09-08 | 2006-03-23 | Directed growth of nanotubes on a catalyst |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/657,428 US6457350B1 (en) | 2000-09-08 | 2000-09-08 | Carbon nanotube probe tip grown on a small probe |
US10/261,084 US20030094035A1 (en) | 2000-09-08 | 2002-09-30 | Carbon nanotube probe tip grown on a small probe |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/657,428 Continuation US6457350B1 (en) | 2000-09-08 | 2000-09-08 | Carbon nanotube probe tip grown on a small probe |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/763,061 Continuation-In-Part US7032437B2 (en) | 2000-09-08 | 2004-01-22 | Directed growth of nanotubes on a catalyst |
Publications (1)
Publication Number | Publication Date |
---|---|
US20030094035A1 true US20030094035A1 (en) | 2003-05-22 |
Family
ID=24637147
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/657,428 Expired - Lifetime US6457350B1 (en) | 2000-09-08 | 2000-09-08 | Carbon nanotube probe tip grown on a small probe |
US10/261,084 Abandoned US20030094035A1 (en) | 2000-09-08 | 2002-09-30 | Carbon nanotube probe tip grown on a small probe |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/657,428 Expired - Lifetime US6457350B1 (en) | 2000-09-08 | 2000-09-08 | Carbon nanotube probe tip grown on a small probe |
Country Status (1)
Country | Link |
---|---|
US (2) | US6457350B1 (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040055892A1 (en) * | 2001-11-30 | 2004-03-25 | University Of North Carolina At Chapel Hill | Deposition method for nanostructure materials |
US20050133372A1 (en) * | 2001-11-30 | 2005-06-23 | The University Of North Carolina | Method and apparatus for attaching nanostructure-containing material onto a sharp tip of an object and related articles |
US20060198949A1 (en) * | 2005-03-01 | 2006-09-07 | Jonathan Phillips | Preparation of graphitic articles |
US20070014148A1 (en) * | 2004-05-10 | 2007-01-18 | The University Of North Carolina At Chapel Hill | Methods and systems for attaching a magnetic nanowire to an object and apparatuses formed therefrom |
US20070186627A1 (en) * | 2006-02-10 | 2007-08-16 | Sungsoo Yi | High aspect ratio AFM probe and method of making |
US20070281130A1 (en) * | 2006-06-01 | 2007-12-06 | D Urso Brian R | Multi-tipped optical component |
US20080080816A1 (en) * | 2004-07-27 | 2008-04-03 | Ut-Battelle, Llc | Multi-tipped optical component |
US20080105648A1 (en) * | 2004-12-16 | 2008-05-08 | William Marsh Rice University | Carbon nanotube substrates and catalyzed hot stamp for polishing and patterning the substrates |
US20080271522A1 (en) * | 2005-12-07 | 2008-11-06 | Binnig Gerd K | Sample analysis using cantilever probe |
US20090172846A1 (en) * | 2005-06-06 | 2009-07-02 | Centre National De La Recherche Scientifique- Cnrs | Nanometric emitter/receiver guides |
US9828284B2 (en) | 2014-03-28 | 2017-11-28 | Ut-Battelle, Llc | Thermal history-based etching |
CN110774060A (en) * | 2019-11-05 | 2020-02-11 | 陕西科技大学 | Preparation method of crystal orientation and size controllable nanometer needle tip |
US11017980B2 (en) | 2015-04-15 | 2021-05-25 | Fei Company | Method of manipulating a sample in an evacuated chamber of a charged particle apparatus |
Families Citing this family (44)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1054249B1 (en) * | 1998-12-03 | 2007-03-07 | Daiken Chemical Co. Ltd. | Electronic device surface signal control probe and method of manufacturing the probe |
US7258901B1 (en) * | 2000-09-08 | 2007-08-21 | Fei Company | Directed growth of nanotubes on a catalyst |
US7032437B2 (en) * | 2000-09-08 | 2006-04-25 | Fei Company | Directed growth of nanotubes on a catalyst |
JP3948223B2 (en) * | 2001-05-30 | 2007-07-25 | 株式会社日立製作所 | Gene sequence reader |
JP4656761B2 (en) * | 2001-05-31 | 2011-03-23 | オリンパス株式会社 | SPM cantilever |
JP3902925B2 (en) * | 2001-07-31 | 2007-04-11 | エスアイアイ・ナノテクノロジー株式会社 | Scanning atom probe |
US20030143327A1 (en) * | 2001-12-05 | 2003-07-31 | Rudiger Schlaf | Method for producing a carbon nanotube |
US6835613B2 (en) * | 2001-12-06 | 2004-12-28 | University Of South Florida | Method of producing an integrated circuit with a carbon nanotube |
GB2384008B (en) * | 2001-12-12 | 2005-07-20 | Electrovac | Method of synthesising carbon nano tubes |
US7279046B2 (en) * | 2002-03-27 | 2007-10-09 | Nanoink, Inc. | Method and apparatus for aligning patterns on a substrate |
US6871528B2 (en) * | 2002-04-12 | 2005-03-29 | University Of South Florida | Method of producing a branched carbon nanotube for use with an atomic force microscope |
US7112816B2 (en) * | 2002-04-12 | 2006-09-26 | University Of South Flordia | Carbon nanotube sensor and method of producing the same |
US20040022943A1 (en) * | 2002-04-12 | 2004-02-05 | Rudiger Schlaf | Carbon nanotube tweezer and a method of producing the same |
JP2005534515A (en) * | 2002-08-01 | 2005-11-17 | ステイト オブ オレゴン アクティング バイ アンド スルー ザ ステイト ボード オブ ハイヤー エデュケーション オン ビハーフ オブ ポートランド ステイト ユニバーシティー | Method for synthesizing nanoscale structure in place |
KR100527382B1 (en) * | 2002-11-07 | 2005-11-09 | 전자부품연구원 | Scanning probe microscopy tip using carbon nanotube with vertical growth and its method |
WO2004052489A2 (en) * | 2002-12-09 | 2004-06-24 | The University Of North Carolina At Chapel Hill | Methods for assembly and sorting of nanostructure-containing materials and related articles |
US6780664B1 (en) | 2002-12-20 | 2004-08-24 | Advanced Micro Devices, Inc. | Nanotube tip for atomic force microscope |
US7730547B2 (en) * | 2003-01-23 | 2010-06-01 | William Marsh Rice University | Smart materials: strain sensing and stress determination by means of nanotube sensing systems, composites, and devices |
US6969690B2 (en) * | 2003-03-21 | 2005-11-29 | The University Of North Carolina At Chapel Hill | Methods and apparatus for patterned deposition of nanostructure-containing materials by self-assembly and related articles |
US7022976B1 (en) | 2003-04-02 | 2006-04-04 | Advanced Micro Devices, Inc. | Dynamically adjustable probe tips |
DE10342644A1 (en) * | 2003-09-16 | 2005-04-07 | Nanotools Gesellschaft für Spezialanwendungen in der Rastersondenmikroskopie mbH | Raster force microscopy probe has nano structure probe tip arm with integrated CMOS piezoelectric sensor |
JP2007515364A (en) * | 2003-10-16 | 2007-06-14 | ザ ユニバーシティ オブ アクロン | Carbon nanotubes on carbon nanofiber substrate |
JP2005128771A (en) * | 2003-10-23 | 2005-05-19 | Fujitsu Ltd | Data file system, data access server, and data access program |
WO2005059508A2 (en) * | 2003-12-11 | 2005-06-30 | The Trustees Of The University Of Pennsylvania | Cellular probes |
FR2876831B1 (en) * | 2004-10-15 | 2007-02-02 | Commissariat Energie Atomique | DATA RECORDING DEVICE HAVING INCLINED CARBON NANOTUBES AND METHOD FOR MANUFACTURING THE SAME |
CN100417117C (en) * | 2005-06-15 | 2008-09-03 | 华为技术有限公司 | Method for recognizing node accessibility in automatically switched optical network |
WO2007002297A2 (en) | 2005-06-24 | 2007-01-04 | Crafts Douglas E | Temporary planar electrical contact device and method using vertically-compressible nanotube contact structures |
KR100697323B1 (en) * | 2005-08-19 | 2007-03-20 | 한국기계연구원 | Nano tip and fabrication method of the same |
DE102006039651A1 (en) * | 2005-08-31 | 2007-03-22 | Hitachi Kenki Finetech Co., Ltd. | Cantilever and tester |
US7867169B2 (en) * | 2005-12-02 | 2011-01-11 | Abbott Cardiovascular Systems Inc. | Echogenic needle catheter configured to produce an improved ultrasound image |
US7408366B2 (en) * | 2006-02-13 | 2008-08-05 | Georgia Tech Research Corporation | Probe tips and method of making same |
US7572300B2 (en) * | 2006-03-23 | 2009-08-11 | International Business Machines Corporation | Monolithic high aspect ratio nano-size scanning probe microscope (SPM) tip formed by nanowire growth |
US7794402B2 (en) * | 2006-05-15 | 2010-09-14 | Advanced Cardiovascular Systems, Inc. | Echogenic needle catheter configured to produce an improved ultrasound image |
US8130007B2 (en) | 2006-10-16 | 2012-03-06 | Formfactor, Inc. | Probe card assembly with carbon nanotube probes having a spring mechanism therein |
US8354855B2 (en) * | 2006-10-16 | 2013-01-15 | Formfactor, Inc. | Carbon nanotube columns and methods of making and using carbon nanotube columns as probes |
US8149007B2 (en) * | 2007-10-13 | 2012-04-03 | Formfactor, Inc. | Carbon nanotube spring contact structures with mechanical and electrical components |
JP2009109411A (en) * | 2007-10-31 | 2009-05-21 | Hitachi Kenki Fine Tech Co Ltd | Probe, its manufacturing method, and probe microscope of scanning type |
US9494615B2 (en) * | 2008-11-24 | 2016-11-15 | Massachusetts Institute Of Technology | Method of making and assembling capsulated nanostructures |
US20100252317A1 (en) * | 2009-04-03 | 2010-10-07 | Formfactor, Inc. | Carbon nanotube contact structures for use with semiconductor dies and other electronic devices |
US8272124B2 (en) * | 2009-04-03 | 2012-09-25 | Formfactor, Inc. | Anchoring carbon nanotube columns |
KR101090430B1 (en) | 2009-10-09 | 2011-12-06 | 성균관대학교산학협력단 | Optical Fiber Containing Carbon Nanostructure Layer, Optical Fiber Chemical Sensor and Method of Forming Carbon Nanostructure Layer on Optical Fiber Core |
TW201119935A (en) * | 2009-12-04 | 2011-06-16 | Univ Nat Chiao Tung | Catalytic seeding control method |
US8872176B2 (en) | 2010-10-06 | 2014-10-28 | Formfactor, Inc. | Elastic encapsulated carbon nanotube based electrical contacts |
CN111780697B (en) * | 2020-07-14 | 2022-08-23 | 惠州市奥普康真空科技有限公司 | Multi-position crucible positioning method and positioning system |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5307693A (en) | 1993-01-21 | 1994-05-03 | At&T Bell Laboratories | Force-sensing system, including a magnetically mounted rocking element |
US5531343A (en) | 1993-07-15 | 1996-07-02 | At&T Corp. | Cylindrical fiber probe devices and methods of making them |
US5824470A (en) * | 1995-05-30 | 1998-10-20 | California Institute Of Technology | Method of preparing probes for sensing and manipulating microscopic environments and structures |
EP0927331B1 (en) * | 1996-08-08 | 2004-03-31 | William Marsh Rice University | Macroscopically manipulable nanoscale devices made from nanotube assemblies |
US5756887A (en) | 1997-02-27 | 1998-05-26 | Lucent Technologies Inc. | Mechanism for changing a probe balance beam in a scanning probe microscope |
US6159742A (en) * | 1998-06-05 | 2000-12-12 | President And Fellows Of Harvard College | Nanometer-scale microscopy probes |
US6346189B1 (en) * | 1998-08-14 | 2002-02-12 | The Board Of Trustees Of The Leland Stanford Junior University | Carbon nanotube structures made using catalyst islands |
-
2000
- 2000-09-08 US US09/657,428 patent/US6457350B1/en not_active Expired - Lifetime
-
2002
- 2002-09-30 US US10/261,084 patent/US20030094035A1/en not_active Abandoned
Cited By (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7887689B2 (en) | 2001-11-30 | 2011-02-15 | The University Of North Carolina At Chapel Hill | Method and apparatus for attaching nanostructure-containing material onto a sharp tip of an object and related articles |
US20050133372A1 (en) * | 2001-11-30 | 2005-06-23 | The University Of North Carolina | Method and apparatus for attaching nanostructure-containing material onto a sharp tip of an object and related articles |
US20040055892A1 (en) * | 2001-11-30 | 2004-03-25 | University Of North Carolina At Chapel Hill | Deposition method for nanostructure materials |
US7455757B2 (en) | 2001-11-30 | 2008-11-25 | The University Of North Carolina At Chapel Hill | Deposition method for nanostructure materials |
US20080099339A1 (en) * | 2001-11-30 | 2008-05-01 | Zhou Otto Z | Deposition method for nanostructure materials |
US8002958B2 (en) | 2001-11-30 | 2011-08-23 | University Of North Carolina At Chapel Hill | Deposition method for nanostructure materials |
US20080006534A1 (en) * | 2001-11-30 | 2008-01-10 | The University Of North Carolina At Chapel Hill | Deposition method for nanostructure materials |
US20070014148A1 (en) * | 2004-05-10 | 2007-01-18 | The University Of North Carolina At Chapel Hill | Methods and systems for attaching a magnetic nanowire to an object and apparatuses formed therefrom |
US20080080816A1 (en) * | 2004-07-27 | 2008-04-03 | Ut-Battelle, Llc | Multi-tipped optical component |
US7697808B2 (en) * | 2004-07-27 | 2010-04-13 | Ut-Battelle, Llc | Multi-tipped optical component |
US7585420B2 (en) * | 2004-12-16 | 2009-09-08 | William Marsh Rice University | Carbon nanotube substrates and catalyzed hot stamp for polishing and patterning the substrates |
US20080105648A1 (en) * | 2004-12-16 | 2008-05-08 | William Marsh Rice University | Carbon nanotube substrates and catalyzed hot stamp for polishing and patterning the substrates |
US20060198949A1 (en) * | 2005-03-01 | 2006-09-07 | Jonathan Phillips | Preparation of graphitic articles |
US7713577B2 (en) * | 2005-03-01 | 2010-05-11 | Los Alamos National Security, Llc | Preparation of graphitic articles |
US7945966B2 (en) * | 2005-06-06 | 2011-05-17 | Tiberiu Minea | Nanometric emitter/receiver guides |
US20090172846A1 (en) * | 2005-06-06 | 2009-07-02 | Centre National De La Recherche Scientifique- Cnrs | Nanometric emitter/receiver guides |
US20080271522A1 (en) * | 2005-12-07 | 2008-11-06 | Binnig Gerd K | Sample analysis using cantilever probe |
US7806008B2 (en) * | 2005-12-07 | 2010-10-05 | International Business Machines Corporation | Sample analysis using cantilever probe |
US20070186627A1 (en) * | 2006-02-10 | 2007-08-16 | Sungsoo Yi | High aspect ratio AFM probe and method of making |
US7697807B2 (en) * | 2006-06-01 | 2010-04-13 | Ut-Battelle, Llc | Multi-tipped optical component |
US20070281130A1 (en) * | 2006-06-01 | 2007-12-06 | D Urso Brian R | Multi-tipped optical component |
US9828284B2 (en) | 2014-03-28 | 2017-11-28 | Ut-Battelle, Llc | Thermal history-based etching |
US10155688B2 (en) | 2014-03-28 | 2018-12-18 | Ut-Battelle, Llc | Thermal history-based etching |
US11017980B2 (en) | 2015-04-15 | 2021-05-25 | Fei Company | Method of manipulating a sample in an evacuated chamber of a charged particle apparatus |
CN110774060A (en) * | 2019-11-05 | 2020-02-11 | 陕西科技大学 | Preparation method of crystal orientation and size controllable nanometer needle tip |
Also Published As
Publication number | Publication date |
---|---|
US6457350B1 (en) | 2002-10-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6457350B1 (en) | Carbon nanotube probe tip grown on a small probe | |
EP1557843A2 (en) | Directed growth of nanotubes on a catalyst | |
US7258901B1 (en) | Directed growth of nanotubes on a catalyst | |
US7211795B2 (en) | Method for manufacturing single wall carbon nanotube tips | |
EP0413040B1 (en) | Method of producing ultrafine silicon tips for the afm/stm profilometry | |
CN102253245B (en) | Monolithic high aspect ratio nano-size scanning probe microscope (SPM) tip formed by nanowire growth | |
KR101159074B1 (en) | Conductive carbon nanotube tip, probe of scanning probe microscope comprising the same and manufacturing method of the conductive carbon nanotube tip | |
JP2624873B2 (en) | Atomic force microscope probe and method of manufacturing the same | |
US9709597B2 (en) | Miniaturized cantilever probe for scanning probe microscopy and fabrication thereof | |
US6452171B1 (en) | Method for sharpening nanotube bundles | |
EP0397799A1 (en) | A piezoelectric motion transducer and an integrated scanning tunneling microscope using the same. | |
US20080182089A1 (en) | Carbon nanotube device and process for manufacturing same | |
CN1599939B (en) | Microstructures | |
US8595860B2 (en) | Method of fabricating a probe device for a metrology instrument and a probe device produced thereby | |
Hantschel et al. | Diamond scanning probes with sub-nanometer resolution for advanced nanoelectronics device characterization | |
US7151256B2 (en) | Vertically aligned nanostructure scanning probe microscope tips | |
US6780664B1 (en) | Nanotube tip for atomic force microscope | |
TWI287803B (en) | SPM sensor | |
Moloni et al. | Sharpened carbon nanotube probes | |
Zhang et al. | Active CMOS-MEMS conductive probes and arrays for tunneling-based atomic-level surface imaging | |
EP1061529A1 (en) | A probe tip for the investigation of a substrate and a method of fabrication therof | |
EP3809143B1 (en) | A method for scanning probe microscopy | |
US20070155184A1 (en) | Method for producing a nanostructure such as a nanoscale cantilever | |
RU2121657C1 (en) | Process of formation of cantilever of scanning probing microscope | |
KR100617471B1 (en) | Cantilever having piezoelectric actuator and tip with high aspect ratio and method for manufacturing the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: THE REGENTS OF THE UNIVERSITY OF NEW MEXICO, NEW M Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BURANDA, TIONE;WANDINGER-NESS, ANGELA;AGOLA, JACOB ONGUDI;AND OTHERS;SIGNING DATES FROM 20180426 TO 20190128;REEL/FRAME:050512/0592 |