High contrast low metal ion photoresist developing method and composition
CA 1306138 C · Owner: Petrarch Systems, Inc. · Inventors: Blakeney, Andrew J.; Lewis, James M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A novel low metal ion developer composition used in a two step process which provides high contrast images and long developer bath life is provided. The process gives high contrast images. The substrate coated with positive photoresist is exposed then immersed in a "predip" bath rinsed, and then, immersed in the developer bath rinsed and, dried. This process provides high contrast which does not decrease over the life of the developer system. The system consists of 1) a predip solution containing aqueous non-metal ion organic base and a cationic surfactant adjusted to a concentration that does not give development and 2) a developer solution containing an aqueous solution of an non-metal …
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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 August 11, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 11, 2009.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.