Granted Patent
Utility
US 6,280,888 · App. 09/608,168
Phase-shifting mask with multiple phase-shift regions
Inventors:
Takashi Nakabayashi, Koji Matsuoka
Patented Case
View Patent ↗
Granted: Aug 28, 2001
Filed: Jun 30, 2000
Inventors
Takashi Nakabayashi
Koji Matsuoka
Assignee (at issue)
Matsushita Electronics 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.