Granted Patent
Utility
US 5,200,293 · App. 07/793,494
Photoresist composition containing specific amounts of a naphthoquinone diazide sulfonyl ester of tetrahydroxy diphenyl sulfide and a polyhydroxy compound
Inventors:
Reinhard Schulz, Horst Munzel, Ekkehard Bartmann
Patented Case
View Patent ↗
Granted: Apr 6, 1993
Filed: Nov 14, 1991
Inventors
Reinhard Schulz
Horst Munzel
Ekkehard Bartmann
Assignee (at issue)
Ciba-Geigy
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.