Granted Patent
Utility
US 6,004,699 · App. 09/031,107
Photomask used for projection exposure with phase shifted auxiliary pattern
Inventors:
Tadao Yasuzato, Shinji Ishida
Patented Case
View Patent ↗
Granted: Dec 21, 1999
Filed: Feb 26, 1998
Inventors
Tadao Yasuzato
Shinji Ishida
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.