Process for removing contaminant
CA 1314197 C · Owner: International Business Machines Corporation · Inventors: Emmi, Francis; Mlynko, Walter E.; Susko, Robin A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Contaminant is removed from holes by etching in a gaseous plasma by first removing contaminant from the vicinity of the edges of the hole. Next a mask is, provided in the vicinity of the edges to prevent etching by contacting with a gaseous plasma which is different from the gaseous plasma employed in the first etching step. The holes are then etched in a gaseous plasma to remove contaminant from the interior of the holes in the vicinity of the center of the holes whereby the mask protects the edges from being etched.
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 March 9, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 9, 2010.
- 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.