Granted Patent
Utility
US 4,857,142 · App. 07/247,712
Method and apparatus for controlling simultaneous etching of front and back sides of wafers
Inventor:
Daniel J. Syverson
Patented Case
View Patent ↗
Granted: Aug 15, 1989
Filed: Sep 22, 1988
Inventor
Daniel J. Syverson
Assignee (at issue)
FSI INTERNATIONAL, INC.
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.