Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films

Hankins, Matthew G

Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films

Patent · Tue Oct 06 00:00:00 EDT 2009

OSTI ID:971540

Hankins, Matthew G ^[1]

Albuquerque, NM

Etchant solutions comprising a redox buffer can be used during the release etch step to reduce damage to the structural layers of a MEMS device that has noble material films. A preferred redox buffer comprises a soluble thiophosphoric acid, ester, or salt that maintains the electrochemical potential of the etchant solution at a level that prevents oxidation of the structural material. Therefore, the redox buffer preferentially oxidizes in place of the structural material. The sacrificial redox buffer thereby protects the exposed structural layers while permitting the dissolution of sacrificial oxide layers during the release etch.

Research Organization:: Sandia National Laboratories (SNL-NM), Albuquerque, NM

Sponsoring Organization:: United States Department of Energy

DOE Contract Number:: AC04-94AL85000

Assignee:: Sandia Corporation (Albuquerque, NM)

Patent Number(s):: 7,597,819

Application Number:: 11/017,108

OSTI ID:: 971540

Country of Publication:: United States

Language:: English

References (11)

Electrochemical aspects of corrosion resistance and etching of metallizations for microelectronics Comizzoli, R. B.; Frankenthal, R. P.; Hanson, K. J. Materials Science and Engineering: A, Vol. 198, Issue 1-2 https://doi.org/10.1016/0921-5093(95)80070-B	journal	July 1995
Corrosion Rate of n- and p-Silicon Substrates in HF, HF + HCl, and HF + NH[sub 4]F Aqueous Solutions Bertagna, Valérie Journal of The Electrochemical Society, Vol. 146, Issue 1 https://doi.org/10.1149/1.1391568	journal	January 1999
Thiol-based antioxidants Deneke, Susan M. Current Topics in Cellular Regulation https://doi.org/10.1016/S0070-2137(01)80007-8	book	January 2001
Galvanic Cell Formation in Silicon/Metal Contacts: The Effect on Silicon Surface Morphology Xia, X. H.; Ashruf, C. M. A.; French, P. J. Chemistry of Materials, Vol. 12, Issue 6 https://doi.org/10.1021/cm9912066	journal	June 2000
Galvanic cell formation: a review of approaches to silicon etching for sensor fabrication Kelly, J. J.; Xia, X. H.; Ashruf, C. M. A. IEEE Sensors Journal, Vol. 1, Issue 2 https://doi.org/10.1109/JSEN.2001.936930	journal	January 2001
Silicon dioxide sacrificial layer etching in surface micromachining Bühler, J.; Steiner, F-P; Baltes, H. Journal of Micromechanics and Microengineering, Vol. 7, Issue 1 https://doi.org/10.1088/0960-1317/7/1/001	journal	March 1997
IC-Compatible Polysilicon Surface Micromachining Sniegowski, J. J.; de Boer, M. P. Annual Review of Materials Science, Vol. 30, Issue 1 https://doi.org/10.1146/annurev.matsci.30.1.299	journal	August 2000
Electrochemical Coupling Effects on the Corrosion of Silicon Samples in HF Solutions Torcheux, L. Journal of The Electrochemical Society, Vol. 142, Issue 6 https://doi.org/10.1149/1.2044237	journal	January 1995
Etching and Passivation of Silicon in Alkaline Solution: A Coupled Chemical/Electrochemical System Xia, Xinghua; Ashruf, Colin M. A.; French, Patrick J. The Journal of Physical Chemistry B, Vol. 105, Issue 24 https://doi.org/10.1021/jp003208f	journal	June 2001
Kinetics of electrochemical corrosion of silicon wafers in dilute HF solutions Bertagna, Valérie; Plougonven, Christian; Rouelle, François Journal of Electroanalytical Chemistry, Vol. 422, Issue 1-2 https://doi.org/10.1016/S0022-0728(96)04902-9	journal	February 1997
Galvanic etching for sensor fabrication Ashruf, C. M. A.; French, P. J.; Sarro, P. M. Journal of Micromechanics and Microengineering, Vol. 10, Issue 4 https://doi.org/10.1088/0960-1317/10/4/304	journal	October 2000

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