Patents by Inventor John F. Cawston

John F. Cawston has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

Metal ion free photoresist developer composition with lower alkyl quaternary ammonium hydrozide as alkalai agent and a quaternary ammonium compound as surfactant

Patent number: 4628023

Abstract: An aqueous metal ion-free developer composition for developing photoresists comprising a metal ion-free alkali and a metal ion-free surfactant that is a quaternary ammonium compound. The developer permits a reduction of from 20-50% in the energy necessary to expose the photoresist without deleterious effect on image quality and image resolution.

Type: Grant

Filed: March 31, 1986

Date of Patent: December 9, 1986

Assignee: Shipley Company Inc.

Inventors: John F. Cawston, Paul E. Becker

Metal ion free photoresist developer composition with lower alkyl quaternary ammonium hydrozide as alkalai agent and a quaternary ammonium compound as surfactant