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. 18, 2011
Filed:
Jan. 18, 2006
Sumer S. Johal, Walnut Creek, CA (US);
Barton Lane, Pleasanton, CA (US);
Georges J. Gorin, Novato, CA (US);
Sylvia G. J. P. Spruytte, Palo Alto, CA (US);
Herve C. Kieffel, San Francisco, CA (US);
Sumer S. Johal, Walnut Creek, CA (US);
Barton Lane, Pleasanton, CA (US);
Georges J. Gorin, Novato, CA (US);
Sylvia G. J. P. Spruytte, Palo Alto, CA (US);
Herve C. Kieffel, San Francisco, CA (US);
Pivotal Systems Corporation, Pleasanton, CA (US);
Abstract
A method for controlling the plasma etching of semiconductor wafers determines the impedance of a plasma chamber using values representing voltage, current, and the phase angle between them, as provided by a sensor. All or less than all of the data during a first time period may be used to calculate a model. During a second time period, real time data is used to calculate a version of the instant impedance of the chamber. This version of impendence is compared to a time-projected version of the model. The method determines that etching should be stopped when the received data deviates from the extrapolated model by a certain amount. In some embodiments a rolling average is used in the second time period, the rolling average compared to the model to determine the end point condition.