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:
Jan. 03, 2012
Filed:
Sep. 19, 2008
Matthew F. Davis, Felton, CA (US);
Thorsten B. Lill, Santa Clara, CA (US);
Quentin E. Walker, Fremont, CA (US);
Matthew F. Davis, Felton, CA (US);
Thorsten B. Lill, Santa Clara, CA (US);
Quentin E. Walker, Fremont, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
A method for determining the flow rate of a gas includes measuring a first concentration of a calibration gas provided to the process chamber at a first pressure and temperature by directing infrared radiation into the process chamber and monitoring a first amount of infrared radiation absorbed by the calibration gas. A mixture of a second gas and the calibration gas is provided to the process chamber while maintaining the first pressure and temperature. A second concentration of the calibration gas in the mixture is measured by directing infrared radiation into the process chamber and monitoring a second amount of infrared radiation absorbed by the calibration gas. A flow rate of the second gas is calculated by comparing the first and second concentrations of the calibration gas. In one embodiment, the calibration gas and the second gas may not absorb the infrared radiation at the same wavelength.