Granted Patent
Utility
US 5,909,282 · App. 08/866,540
Interferometer for measuring thickness variations of semiconductor wafers
Inventor:
Andrew W. Kulawiec
Patented Case
View Patent ↗
Granted: Jun 1, 1999
Filed: May 30, 1997
Inventor
Andrew W. Kulawiec
Assignee (at issue)
Tropel 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.