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:
Aug. 30, 2011
Filed:
Jul. 11, 2005
Andre P. Labonte, Lewiston, ME (US);
Craig Richard Printy, Buxton, ME (US);
Andre P. Labonte, Lewiston, ME (US);
Craig Richard Printy, Buxton, ME (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A system and method is disclosed that terminates an etch process of a semiconductor crystal material at a precisely located depth. The semiconductor crystal is made of a first material and has a buried layer of a second material that is stoichiometrically different than the first material. The buried layer is located at a depth in the first material at which it is desired to terminate the etch process. During the etch process an optical emission spectrum of the first material is monitored. The intensity of the spectrum decreases when the etch process reaches the second material of the buried layer. The etch process is terminated when the decrease in spectrum intensity is detected.