Granted Patent
Utility
US 6,821,687 · App. 10/112,716
Photo mask for fabricating semiconductor device having dual damascene structure
Inventors:
Nobuaki Hamanaka, Takashi Yokoyama, Kazutoshi Shiba, Noriaki Oda
Patented Case
View Patent ↗
Granted: Nov 23, 2004
Filed: Apr 2, 2002
Inventors
Nobuaki Hamanaka
Takashi Yokoyama
Kazutoshi Shiba
Noriaki Oda
Assignee (at issue)
NEC 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.