High molecular weight siloxane polyimides, intermediates therefor, and methods for their preparation and use

摘要

High molecular weight siloxane polyamic acids and polyimides are prepared by the reaction of dianhydrides with diamines in a polar aprotic solvent, all of the reagents and solvent being highly purified and substantially anhydrous. The polyamic acids may be coated on substrates and baked to form polyimide dielectric layers. When so used, they are free from certain disadvantages of lower molecular weight polymers, especially undercutting and scum formation during photolithography and etching procedures.