Bilevel ultraviolet resist system for patterning substrates of high reflectivity
CA 1194615 A · Owner: Western Electric Company, Incorporated · Inventors: Ong, Edith T.T.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, A bilevel photoresist system 10 of two organic photoresists, both sensitive to deep ultraviolet (UV) radiation from the same deep UV source (e.g. Xe-Hg) and suitable for use in patterning a substrate of high reflectivity in the deep UV, comprises a top layer of a negative photoresist (e.g. the azide-phenolic resin diazidodiphenyl sulfone mixed into poly(p-vinylphenol) having a thickness of about 0.5 micron and a bottom layer, of positive photoresist (e.g. poymethyl methacrylate) having a thickness about 1 or 2 microns. The top layer is thus of sufficient thickness to be substantially opaque to the deep UV radiation from the source. The top layer is patterned by projecting the deep …
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 October 1, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 1, 2002.
- 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.