Expired Canadian patentCanada
Method of manufacturing semiconductor devices in which silicon oxide regions inset in silicon are formed by a masking oxidation, and semiconductor devices manufactured in this manner
CA 970478 A · Owner: N.V. Philips Gloeilampenfabrieken · Inventors: Verkuijlen, Wilhelmus H.C.G.; Appels, Johannes A.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
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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 July 1, 1975. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 1, 1992.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedJuly 1, 1975
Term endedJuly 1, 1992
Patent numberCA 970478 A
Classification (IPC)H01L27/04 +2 more
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.