Planarizing method for refilled trenches
CA 2087235 A1 · Owner: Abraham, Thomas · Inventors: Tay, Sing Pin; Ellul, Joseph Paul; Abraham, Thomas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
11, Abstract of the Disclosure, A method of planarizing a surface of a semiconductor substrate containing a trench refiled by forming a polysilicon layer with a thickness of half the width of the trench over a conformal layer on the substrate and in the trench is described. Most of the, polysilicon layer is oxidized in a controlled manner with a stressed region of the, polysilicon centrally over the trench being oxidized at a reduced rate which compensates for a dip in the polysilicon layer at this point to leave a thin layer of unoxidized, polysilicon which has a planar interface with the oxidized polysilicon The oxidized, polysilicon is wet etched using the thin layer of unoxidized …
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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 January 13, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 13, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 13, 2015.
- 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.