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Expired Canadian patentCanada

Deposition of tungsten on silicon in a non-self-limiting cvd process

CA 1308496 C · Owner: International Business Machines Corporation · Inventors: Joshi, Rajiv V.

CIPO record

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Abstract From the Canadian patent

A method of depositing tungsten on a substrate utilizing silicon reduction wherein the process is non-limiting as to the thickness of silicon that may be converted to tungsten. A silicon substrate is provided with at least one area of silicon material having a predetermined thickness and the substrate is exposed to a tungsten hexafluoride gas flow in a chemical vapor deposition environment. By adjusting the WF6 gas flow rate and the CVD process parameters, such as pressure temperature and deposition time, the thickness of silicon converted to tungsten can be adjusted in order to convert the entire thickness. A novel structure having a midgap tungsten gate and tungsten source and drain …

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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 October 6, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 6, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 20, 1988
GrantedOctober 6, 1992
Term endedOctober 6, 2009
Patent numberCA 1308496 C
Classification (IPC)C23C16/04 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedOct 20, 1988Patent grantedOct 6, 1992Term endedOct 6, 2009

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