Selective electrochemical etching

Details Selective electrochemical etching Selective electrochemical etching

1991-03-15

1992-07-14

Powell, William A.

Adhesive bonding and miscellaneous chemical manufacture

Delaminating processes adapted for specified product

Delaminating in preparation for post processing recycling step

156647, 156653, 156657, 1566591, 156662, 252 795, 20412965, H01L 21306, B44C 122, C03C 1500, C03C 2506

Patent

active

051299828

ABSTRACT:
A method of selectively etching a body of a semiconductor material, such as single crystalline silicon, having regions of n-type and p-type conductivity to remove at least a portion of the n-type region. The body is placed in an etching solution of an etchant having a high pH value and a positive voltage is applied between the body and the etchant. This forms passivating layers on the surfaces of the two regions with the passivating layer on the n-type region being different from that on the p-type region. The voltage is then removed and the body is etched for a period long enough to remove all of the passivating layer from the n-type region and at least a portion of the n-type region, but is not long enough to remove all of the passivating layer from the p-type region. This is allowed by the difference between the passivating layers on the two regions. The steps of forming the passivating layers and etching them is repeated until a desired amount of the n-type region is removed.

REFERENCES:
J. A. Oakes, "A Pressure Sensor for Automotive Application", Proceedings of Third International Conference on Automotive Electronics, pp. 143-149, 20-23 Oct. 1981, London, England (published by Mechanical Engineering Publications of London, England).
K. D. Wise and S. K. Clark, "Diaphragm Formation and Pressure Sensitivity in Batch-Fabricated Silicon Pressure Sensors", IEDM Technical Digest, International Electron Devices Meeting, Washington, D.C., Dec. 4-6, 1978, pp. 96-98.
R. L. Smith, B. Kloeck, N. DeRooij and S. D. Collins, "The Potential Dependence of Silicon Anisotropic Etching in KOH at 60.degree. C.", J. Electroanal. Chem., vol. 238, pp. 103-113 (1987).
I. Barycka, H. Teterycz, and Z. Znamirowski, "Sodium Hydroxide Solution Shows Selective Etching of Boron-Doped Silicon", J. Electrochem. Soc., vol. 126, pp. 345-346, Feb. 1979.
N. F. Raley, Y. Sugiyama, and T. VanDuzer, "(100) Silicon Etch-Rate Dependence on Boron Concentration in Ethylenediamine-Pyrocatechol-Water Solutions", J. Electrochem. Soc., vol. 131, pp. 161-171, Jan. 1984.
E. D. Palik, V. M. Bermudez, and O. J. Glembocki, "Ellipsometric Study of the Etch-Stop Mechanism in Heavily Doped Silicon", J. Electrochem. Soc., vol. 132, pp. 135-141, Jan. 1985.
H. Seidel, "The Mechanism of Anisotropic, Electrochemical Silicon Etching in Alkaline Solutions", IEEE Solid-State Sensor and Actuator Workshop, Hilton Head Island, pp. 86-91, 1990.
H. A. Waggener, "Electrochemically Controlled Thinning of Silicon", The Bell System Technical Journal, pp. 473-475, Mar. 1970.
H. A. Waggener and J. V. Dalton, "Control of Silicon Etch Rates in Hot Alkaline Solutions by Externally Applied Potentials", Electrochem. Soc. Ext. Abstr. No. 237, pp. 587-589, Fall Meeting, 1972.
T. N. Jackson, M. A. Tischler, and K. D. Wise, "An Electrochemical P-N Junction Etch-Stop for the Formation of Silicon Microstructures", IEE Electron Device Letters, vol. EDL-2, No. 2, pp. 44-45, Feb. 1981.
S. C. Kim and K. D. Wise, "Temperature Sensitivity in Silicon Piezoresistive Pressure Transducers", IEEE Transactions on Electron Devices, vol. ED-30, No. 7, pp. 802-810, Jul. 1983.
P. M. Sarro and A. W. vanHerwaarden, "Silicon Cantilever Beams Fabricated by Electrochemically Controlled Etching for Sensor Applications", J. Electrochem. Soc., vol. 133, pp. 1724-1729, Aug. 1986.
M. Hirata, S. Suwazono, and H. Tanigawa, "Diaphragm Thickness Control in Silicon Pressure Sensors Using an Anodic Oxidation Etch-Stop", J. Electrochem. Soc., vol. 134, No. 8, pp. 2037-2041, Aug. 1987.
B. Kloeck, S. D. Collins, N. F. DeRooij, and R. L. Smith, "Study of Electrochemical Etch-Stop for High-Precision Thickness Control of Silicon Membranes", IEEE Transactions on Electron Devices, vol. 36, No. 4, pp. 663-669, Apr. 1989.
Y. Linden, L. Tenerz, J. Tiren and B. Hok, "Fabrication of Three-Dimensional Silicon Structures by Means of Doping-Selective Etching (DSE)", Sensors and Actuators, 16, pp. 67-82, 1989.
Y. P. Xu and R. S. Huang, "Anodic Dissolution and Passivation of Silicon in Hydrazine", J. Electrochem. Soc., vol. 137, No. 3, pp. 948-953, Mar. 1990.
V. M. McNeil, S. S. Wang, K-Y Ng, and M. A. Schmidt, "An Investigation of the Electrochemical Etching of (100) Silicon in CsOH and KOH", IEEE Solid-State Sensor and Actuator Workshop, Hilton Head Island, pp. 92-97, 1990.
E. D. Palik, J. W. Faust, Jr., H. F. Gray, and R. F. Greene, "Study of the Etch-Stop Mechanism in Silicon", J. Electrochem. Soc., vol. 129, No. 9, pp. 2051-2059, 1982.
J. W. Faust, Jr. and E. D. Palik, "Study of the Orientation Dependent Etching and Initial Anodization of Si in Aqueous KOH", J. Electrochem. Soc., vol. 130, pp. 1413-1420, Jun. 1983.
O. J. Glembocki, R. E. Stahlbush, and M. Tomkiewicz, "Bias-Dependent Etching of Silicon in Aqueous KOH", J. Electrochem. Soc., vol. 132, No. 1, pp. 145-151, Jan. 1985.
R. L. Smith, B. Kloeck, N. F. DeRooij, and S. D. Collins, "The Potential Dependence of Silicon Anisotropic Etching in KOH at 60.degree. C.", J. Electroanalytical Chem. and Interfacial Electrochem., 238, pp. 103-113, 1987.
L. D. Clark, Jr., J. L. Lund, and D. J. Edell, "Cesium Hydroxide (CsOH): A Usual Etchant for Micromachining Silicon", IEEE Solid-State Sensor and Actuator Workshop, Hilton Head Island, Jun. 1988.
L. D. Clark, Jr. and D. J. Edell, "KOH:H.sub.2 O Etching of (110) Si, (111) Si, SiO.sub.2, and Ta: An Experimental Study", IEEE Microrobots and Teleoperators Workshop, Hyannis, Mass., Nov. 1987.

Affiliated with

Also associated with

Rating

Selective electrochemical etching does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Selective electrochemical etching, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Selective electrochemical etching will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-332724