Gaseous plasma etching of aluminum and aluminum oxide
CA 1059882 A · Owner: Northern Telecom Limited · Inventors: Nentwich, Heinz J.; Poulsen, Robert G.; Ingrey, Sidney I.J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, Gaseous plasma etching of aluminum with conventional plasma etch gases has not hitherto been commercially possible due to a layer of aluminum oxide (Al2O3) which forms on freshly prepared aluminum surfaces. By first plasma etching in the presence of a gaseous trihalide preferably, in a so-called "pancake" or radial-flow-type reactor the oxide, layer is removed. Aluminum etching can then continue either, with or without plasma conditions depending upon the etch gas, used. - i -
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted August 7, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 7, 1996.
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Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.