The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 10, 1998
Filed:
Jul. 10, 1997
James J McAndrew, Lockport, IL (US);
Ronald S Inman, Lyons, IL (US);
American Air Liquide Inc., Walnut Creek, CA (US);
Abstract
A novel method for calibration of a spectroscopic sensor is provided. In the method, a spectroscopic system is provided. The system includes a measurement cell having one or more walls which at least partially enclose a sample region. The cell further includes a light entry port and a light exit port. The light entry port and the light exit port can be the same port or separate ports. Each of the ports contains a light transmissive window through which a light beam passes along an internal light path inside the measurement cell. The system further has an optical chamber which contains a light source for generating the light beam which passes through the light entry port into the cell, and a detector for measuring the light beam exiting the cell through the light exit port. The light beam passes along an external light path inside the optical chamber. In addition, a gas inlet is connected to the optical chamber. A calibration gas stream is introduced into the optical chamber. The calibration gas stream contains a calibrating gas species and a carrier gas. The calibrating gas species is present in the calibration gas stream in a known concentration. A spectroscopy measurement of the calibration gas stream is then performed. The method finds particular applicability in the calibration of an in-line spectroscopic sensor useful in the detection of molecules of interest in a semiconductor processing tool.