Granted Patent
Utility
US 5,908,718 · App. 08/828,531
Phase shifting photomask with two different transparent regions
Inventors:
Shinji Ishida, Tadao Yasuzato
Patented Case
View Patent ↗
Granted: Jun 1, 1999
Filed: Mar 31, 1997
Inventors
Shinji Ishida
Tadao Yasuzato
Assignee (at issue)
NEC 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.