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

Abstract

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.

Inventors:
 [1]
  1. Albuquerque, NM
Publication Date:
Research Org.:
Sandia National Laboratories (SNL-NM), Albuquerque, NM
Sponsoring Org.:
USDOE
OSTI Identifier:
971540
Patent Number(s):
7,597,819
Application Number:
11/017,108
Assignee:
Sandia Corporation (Albuquerque, NM) SSO
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Hankins, Matthew G. Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films. United States: N. p., 2009. Web.
Hankins, Matthew G. Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films. United States.
Hankins, Matthew G. Tue . "Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films". United States. https://www.osti.gov/servlets/purl/971540.
@article{osti_971540,
title = {Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films},
author = {Hankins, Matthew G},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2009},
month = {10}
}

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