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:
Oct. 13, 2009
Filed:
Apr. 22, 2008
Gernot Biese, Marzling, DE;
Ulrich Clement, Puchheim, DE;
Gernot Biese, Marzling, DE;
Ulrich Clement, Puchheim, DE;
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A method of processing semiconductor wafers comprises forming a pattern of recesses in an exposed surface of each wafer in a lot, prior to an epitaxy step. At least one recessed test structure is included in the pattern of recesses. At least one dimension of the recessed test structure is determined prior to the epitaxy step, then a corresponding dimension of an epitaxial structure grown above the recessed test structure in the epitaxy step is measured. A deviation between the dimension of the recessed test structure and the dimension of the epitaxial structure is determined and, from the deviation, the process temperature at which the epitaxy step was performed is determined. In case the deviation exceeds a predetermined limit, the temperature in the process chamber is adjusted for a subsequent lot of wafers to be processed.