Granted Patent
Utility
US 6,266,996 · App. 09/167,197
Simple and inexpensive method and device for measuring concentration and rate of change of a crystal etchant gas, such as HF or DF gas
Inventor:
Peter M. Livingston
Patented Case
View Patent ↗
Granted: Jul 31, 2001
Filed: Oct 6, 1998
Inventor
Peter M. Livingston
Assignee (at issue)
TRW Limited
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.