Etching techniques
CA 1235630 A · Owner: American Telephone And Telegraph Company · Inventors: Ibbotson, Dale E.; Flamm, Daniel L.; Mucha, John A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, A highly selective --greater than 100 to 1-- etch for silicon, tantalum, molybdenum and tungsten and non-oxidic tantalum, molybdenum and tungsten compositions such as tantalum silicide and tantalum nitride molybdenum, silicide and tungsten silicide,relative to their oxidic counterparts and silicon nitride is achieved by using polyatomic halogen fluorides. The selectivity (3) which is greater than 100 to 1 for silicon, tantalum and non-oxidic tantalum, is achievable without employing plasmas or wet etching.
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
- Granted April 26, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 26, 2005.
- 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.