Etching a substrate: processes – Nongaseous phase etching of substrate – Etching inorganic substrate
Reexamination Certificate
2005-01-18
2005-01-18
Barr, Michael (Department: 1746)
Etching a substrate: processes
Nongaseous phase etching of substrate
Etching inorganic substrate
C216S108000, C216S109000, C205S640000, C205S666000, C205S667000, C205S670000, C205S674000, C252S079200
Reexamination Certificate
active
06843929
ABSTRACT:
A method and associated structure for increasing the rate at which a chromium volume is etched when the chromium body is contacted by an acid solution such as hydrochloric acid. The etch rate is increased by a metallic or steel body in continuous electrical contact with the chromium volume, both of which are in continuous contact with the acid solution. At a temperature between about 21° C. and about 52° C., and a hydrochloric acid concentration (molarity) between about 1.2Mand about 2.4M, the etch rate is at least a factor of about two greater than an etch rate that would occur in an absence of the steel body. In one embodiment, the chromium volume is a chromium layer that rests upon a conductive layer that includes a metal such as copper, wherein the acid solution is not in contact with the conductive layer. In another embodiment, the chromium volume is a chromium layer located under a conductive layer that includes a metal such as copper, wherein the steel body and the acid solution both contact the chromium layer through an opening in the conductive layer such that the opening exposes the chromium layer.
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Farquhar Donald S.
Fey Edmond O.
Foster Elizabeth
Klodowski Michael J.
Rickerl Paul G.
Barr Michael
International Business Machines - Corporation
Schmeiser,Olsen & Watts
Steinberg William H.
Winter Gentle E.
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