Process for preparing radiation sensitive compound and positive resist composition
CA 2065468 A1 · Owner: Tomioka, Jun · Inventors: Doi, Yasunori; Kuwana, Koji; Tomioka, Jun
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A radiation sensitive compound prepared by reacting a phenol compound with a quinone diazide sulfonyl halide in a mixture of a solvent having a relative dielectric constant of not larger than 10 and a solvent having a relative dielectric constant of at least 15 which compound, is less colored and gives a positive resist composition having a good resolution.
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 April 7, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 7, 2014.
- 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.