Processing method for fabricating electrical contacts to mesa structures in semi-conductor devices
CA 2072617 A1 · Owner: Gte Laboratories Incorporated · Inventors: Holmstrom, Roger P.; Crawford, F. David; Meland, Edmund
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A semiconductor mesa structure (20) is covered with a photoresist material (22) in a localized flooding manner such that the photoresist material (22) is thinner on the top of the mesas (21) and also at the uppermost portion of the sidewalls than at the base of the mesa (21) and the intervening channel. The photoresist (22) is then exposed through a mask (23) in a manner so that when developed, the photoresist (22) from the mesa (21) top and uppermost portion of the sidewall can be removed. When the photoresist (22) is exposed to the actinic radiation the thinner photoresist, (22) is adequately exposed more rapidly than the thicker portion nearer the bottom of the mesa (21), if the mask …
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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
- Filed September 12, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 12, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 12, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
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.