Method of manufacturing semiconductor device with overvoltage self-protection
CA 1293334 C · Owner: Kanaya, Masatoshi · Inventors: Tsunoda, Yoshiaki; Kanaya, Masatoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of manufacturing a semiconductor device with overvoltage self-protection of punchthrough type comprises the following steps. (a) A step of making a recess in a P gate-base layer from its surface exposed to the top surface of a substrate. In this step, the recess is formed to such depth that a space-charge layer produced in the gatebase layer when a predetermined breakover voltage for self-protection is applied to a thyristor reaches at least the bottom of the recess, and the bottom of the recess extends close to a junction between the gate-base layer and an emitter layer. (b) A step of doping the gate-base layer with P type impurities from the bottom of the recess to gatebase layer …
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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 December 17, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 17, 2008.
- 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.