3-step etching for contact window
CA 2238128 A1 · Owner: Chen, Jeng-Pei · Inventors: Chen, Jeng-Pei; Wang, Fang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A 3-step etching method for contact windows in integrated circuit devices is disclosed, the first step being an anisotropic etching, the second step being an isotropic etching and the third step being an anisotropic etching, where the ratio of the etching depth formed by the third step to the total etching depth formed by said three steps is less than 0.5. The resultant contact window has a better aluminum step coverage, making more reliable electrical connections and without increasing much cost.
Read the whole patent
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 May 20, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 20, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 20, 2020.
- 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.