USOO5883564A United States Patent (19) 11 Patent Number: 5,883,564 Partin (45) Date of Patent: *Mar 16, 1999 54) MAGNETIC FIELD SENSOR HAVING HIGH OTHER PUBLICATIONS MOBILITY THIN INDUMANTMONDE ACTIVE LAYER ON THIN ALUMINUM Baltes et al., “Integrated Semiconductor Magnetic Field INDUMANTMONDE BUFFER LAYER Sensors”, Proceedings of the IEEE, Vol. 74, No. 8, Aug. 1986, pp. 1107–1132. 75 Inventor: Dale Lee Partin, Ray, Mich. Bougnot et al., “Growth of GaAl,Sb and Ga. InSb by Organometallic Chemical Vapor Deposition”, Journal of 73 Assignee: General Motors Corporation, Detroit, Crystal Growth 77 (1986), pp. 400–407. Mich. Chyi et al., “Molecular Beam Epitaxial Growth and Char * Notice: This patent issued on a continued pros- acterization of InSb on Si”, App. Phys. Lett. 54 (11), 13 Mar. ecution application filed under 37 CFR 1989, pp. 1016–1018. 1.53(d), and is subject to the twenty year Dobbelaere et al., “Growth and Optical Characterization of patent term provisions of 35 U.S.C. InAsSb.(0sxs1) on GaAs and on GaAs-Coated Si by 154(a)(2). Molecular Beam Epitaxy”, App. Phys. Lett. 55 (18), 30 Oct. 1989, pp. 1856–1858. Du et al., “Molecular Beam Epitaxial GainSbBi for Infrared 21 Appl. No.:710,125 Detector Applications”, Ninth International Conference on 22 Filed: Sep. 11, 1996 Molecular Beam Epitaxy, Aug. 5-9, 1996, Malibu, Califor a. Related U.S. Application Data Heremans, “Solid State Magnetic Field Sensors and Appli 63 Continuation-in-part of Ser. No. 228,766, Apr. 18, 1994, cations”, J. Phys.y D. Appl.pp Phys.y 26 ((1993), ), pppp. 1149–1168. abandoned. Jou et al., “Organometallic Vapor-Phase Epitaxial Growth 6 and Characterization of the Metastable Alloy InP, Sb, J. 51 Int. C. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - HOL 43/00 Appl. Phys., vol. 64, No. 3, 1. Aug. 1988, pp. 1472-1475. 52 U.S. Cl. .................. 338/32 R; 338/32 H; 360/113 Gnezdilov et al., “Resonant Raman Scattering in InSb/ 58 Field of Search ". 38.32 R, 324; In AlSb Superlattices”, Physical Review B, vol. 48, No. 257425; 360/113,324/252 11, 15 Sep.1993, pp. 8442-8445. 56) References Cited (List continued on next page.) U.S. PATENT DOCUMENTS Primary Examiner Michael L. Gellner 2,778,802 1/1957 Lardson et al. ................. 252/62.3 GA ASSistant Examiner Karl Easthom 3,321,384 5/1967 Weider et al. .......................... 257/425 Attorney, Agent, or Firm-George A. Grove 3,852,103 12/1974 Collins et al. ... 338/32 R 4.224,594 9/1980 Anthony et al. ..... 338/32R 57 ABSTRACT 4,236,165 11/1980 Kawashima et al. ..................... 357/16 4,251,795 2/1981 Shibasaki et al. ....... 338/32 R A magnetic field sensor is described that has a 0.25-0.6 4.912,451 3/1990 Sugiyama et al. .................... 338/32 R micrometer thick magnetically active layer of Very high 4,926,122 5/1990 Schroeder et al. ... ... 324/207.13 electron mobility that consists essentially of epitaxial indium 4,926,154 5/1990 Heremans et al. .................... 338/32 R antimonide. The indium antimonide layer is disposed on a 4,926,226 5/1990 Heremans et al......... 357/27 0.03–1.0 micrometer thick buffer layer of InAlSb, where 3. 3. Mill al. - - - 35. “X” is about 0.01-0.2, that is substantially lattice-matched to 4,981,3412 - Y-2 1/1991 Brandle,aIIIl C Jr.al. et. al.. .................... , the indium- antimonide active layer. (List continued on next page.) 17 Claims, 3 Drawing Sheets 16 18 12 5,883,564 Page 2 U.S. PATENT DOCUMENTS Oshima et al., “Initial Stages of Nanocrystal Growth of Compound Semiconductors on Si Substrates”, Journal of 5,038,131 8/1991 Olk et al. .............................. 338/32 R 5,153,557 10/1992 Partin et al. .......................... 338/32 R Electron Spectroscopy and Related Phenomena 80 (1996), 5,184,106 2/1993 Partin et al. .. 338/32 R pp. 129-132. 5,189,367 2/1993 Lee et al. .......... ... 324/252 Partin et al., “Growth on High Mobility InSb by Metalor 5,314,547 5/1994. Heremans et al. ... 147/33.1 ganic Chemical Vapor Deposition”, Journal of Electronic 5,385.864 1/1995 Kawasaki et al. ... 437/132 5,442,221 8/1995 Mosser et al. .......................... 257/425 Materials, vol. 23, No. 2, 1994, pp. 75–79. 5,453,727 9/1995 Shibasaki et al. .................... 338/32 R Partin et al., “Growth and Characterization of Indium Anti 5,486,804 1/1996 Sokolich et al. ...................... 338/32 R monide Doped with Lead Telluride”, Journal of Applied 5,491,461 2/1996 Partin et al. .......................... 338/32 R Physics, vol. 71, No. 5, 1 Mar. 1992, pp. 2328-2332. OTHER PUBLICATIONS Rao et al., “Be, S, Si and Ne Ion Implantation in InSb Growth Li et al., “Molecular-Beam Epitaxial Growth on InSb on on GaAs, Journal of Applied Physics, vol. 69, No. 8, 15 GaAs and Si for Infrared Detector Applications”, J. Vac. Sci. Apr. 1991, pp. 4228–4233. Technol. B 11 (3), May/Jun. 1993, pp. 872-874. Rao et al., “Heteroepitaxy of InSb on Silicon by Metalor Liu et al., “Molecular-Beam Epitaxial Growth and Charac ganic Magnetron Sputtering”, Applied Physics Letters 53 terization of AlInSb/InSb Quantum Well Structures”, J. (1), 4 Jul. 1988, pp. 51-53. Vac. Sci. Technol. B 14(3), May/Jun. 1996, pp. 2339–2342. Madelung et al, editors, “Semiconductors”, vol. 17 of Teede, “Single Crystal InSb Thin Films by Electron Beam Landolt-Bornstein-Numerical Data and Functional Rela Re-Crystallization”, Solid State Electronics, vol. 10, 1967, tionships in Science and Technology, 1982, p. 623. pp. 1069–1076. Mani et al., “Temperature-Insensitive Offset Reduction in a Uppal et al., “Transport Properties of Heterostructures Based Hall Effect Device”, Appl. Phys. Lett. 64 (23), 6 Jun. 1994, on GaSb, InAS and InSb onGaAs Substrates”, Journal of pp. 3121–3123. Crystal Growth 111 (1991), pp. 623–627. U.S. Patent Mar 16, 1999 Sheet 1 of 3 5,883,564 FIG - 1 16 18 12 FIG - 2 16 18 2 14a U.S. Patent Mar 16, 1999 Sheet 2 of 3 5,883,564 20a 2OC FIG - 3A PRIOR ART 10a 1 OC 2Od U.S. Patent Mar 16, 1999 Sheet 3 of 3 5,883,564 5.4 5.5 5.6 5.7 5.8 5.9 6.0 6.1 6.2 6.3 6.4 6.5 LATTICE CONSTANT (A) FIG - 4 5,883,564 1 2 MAGNETIC FIELD SENSOR HAVING HIGH Voltage bias. Alternatively, it provides a larger output Volt MOBILITY THIN INDUMANTIMONIDE age (change in Voltage when the magnetic field changes) for ACTIVE LAYER ON THINALUMINUM a given current bias. This favors use of thin films of indium INDUMANTIMONDE BUFFER LAYER antimonide for magnetic field Sensors, to obtain Sensors of lower power consumption. RELATED PATENT APPLICATION In the past, thin layers of indium antimonide were made This patent application is a continuation-in-part to my by thinning down high quality bulk monocrystals. They previously filed U.S. patent application Ser. No. 08/228,766, were thinned down to layers of approximately twenty now abandoned, entitled “Indium Antimonide Alloys for micrometers in thickness. Thinner layers were desired, for Magnetic Field Sensors”, which was filed Apr. 18, 1994. The reducing Series resistance of Sensors made from Such films. teachings of the above mentioned U.S. Ser. No. 08/228,766 However, thinner layers were difficult to produce by thin are hereby incorporated herein by reference. ning bulk crystals. This led to the more recent practice of growing a thin epitaxial film of indium antimonide on an FIELD OF THE INVENTION insulating or semi-insulating gallium arsenide (GaAs) or 15 indium phosphide (InP) substrate. The substrate is of high This invention relates to improvements in magnetic field electrical resistance to minimize its non-magnetically Sen Sensors that are of the indium antimonide type. It more Sitive conductivity, that is electrically in parallel with the particularly relates to very thin film alloys of indium anti magnetically Sensitive conductivity of the epitaxial film. monide for magnetic field Sensors. Such epitaxial films are typically grown to a thickness of only 2–5 micrometers. This increases film sheet resistance BACKGROUND OF THE INVENTION (film resistivity divided by thickness) by an order of mag Indium Antimonide (InSb) is widely recognized as being nitude over the thinned-down bulk crystal films. However, useful in magnetic field Sensors, Such as magnetoresistors, even then, Such films still have had such a low sheet Hall Effect sensors (Hall sensors), and MAGFETS resistance that other techniques are used to increase total (magnetically sensitive field effect transistors). Indium anti 25 Sensor resistance. For example, extensive Serialization of monide magnetic field Sensors can be used in a variety of magnetoresistor units has been used to obtain high Sensor magnetic field Sensing applications, including position, impedances, and the attendant low power dissipation. Speed and acceleration sensing (linear or angular), compass In the case of magnetoresistors, a higher total resistance Sensors, magnetic memory readout and control of brushleSS is obtained by integrating many Series-connected rectangu motors. While an emphasis of this invention is on automo lar magnetoresistor units into one Sensor body. Typically, the tive applications, the applicability is general. body is an elongated mesa or line of indium antimonide. The Indium antimonide is particularly attractive for use in mesa is a line of rectangular Sensing units that are connected magnetic field Sensors because it is a material that has end-to-end, in Series fashion. The mesa or line, i.e., the exhibited high electron mobility in bulk form. High electron Series-connected magnetoresistor rectangle units, can be as mobility is important because it provides high magnetic 35 long as needed to obtain the desired total resistance.