Granted Patent
Utility
US 4,885,232 · App. 06/921,879
High temperature post exposure baking treatment for positive photoresist compositions
Inventor:
Mark A. Spak
Patented Case
View Patent ↗
Granted: Dec 5, 1989
Filed: Oct 17, 1986
Inventor
Mark A. Spak
Assignee (at issue)
Hoechst Celanese Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.