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Expired Canadian patentCanada

Device manufacture involving lithographic processing

CA 2020237 C · Owner: Gibson, John Murray · Inventors: Berger, Steven David; Gibson, John Murray

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

Abstract, Fabrication of devices of micron and submicron minimum feature size is accomplished by lithographic processing involving a back focal plane filter. A particularly important fabrication approach depends upon mask patterns which produce images based on discrimination as between scattered and unscattered radiation by accelerated electrons.

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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 June 29, 1990 and granted June 7, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 29, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 29, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 29, 1990
GrantedJune 7, 1994
Term endedJune 29, 2010
Patent numberCA 2020237 C
Classification (IPC)H01L21/46 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJune 29, 1990Patent grantedJune 7, 1994Term endedJune 29, 2010

Sources & verification

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