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Expired Canadian patentCanada

Method for forming isolated regions of silicon

CA 1108772 A · Owner: International Business Machines Corporation · Inventors: Pogge, H. Bernhard; Bondur, James A.

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Abstract of the Disclosure, A method for isolating regions of silicon involving the formation of openings that have a suitable taper in a block of silicon, thermally oxidizing the surfaces of the openings, and filling the openings with a dielectric material to isolate regions of silicon within the silicon block. The method is particularly useful wherein the openings are made through a region of silicon having a layer of a high doping conductivity.

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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 September 8, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 8, 1998.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 9, 1980
GrantedSeptember 8, 1981
Term endedSeptember 8, 1998
Patent numberCA 1108772 A
Classification (IPC)H01L21/31

Timeline

Timeline From CIPO dates

198119831985198719891991199319951997Application filedJuly 9, 1980Patent grantedSep 8, 1981Term endedSep 8, 1998

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.