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:
Sep. 17, 2013
Filed:
Apr. 25, 2011
Timothy a Johnson, Tigard, OR (US);
Michael J Darwin, Portland, OR (US);
Timothy A Johnson, Tigard, OR (US);
Michael J Darwin, Portland, OR (US);
Nanometrics Incorporated, Milpitas, CA (US);
Abstract
An optical metrology device determines the local stress in a film on a substrate. The metrology device maps the thickness of the substrate prior to processing. After processing, the metrology device determines the surface curvature of the substrate caused by the processing and maps the thickness of a film on the top surface after of the substrate after processing. The surface curvature of the substrate may be determined as basis functions. The local stress in the film is then determined using the mapped thickness of the substrate, the determined surface curvature, and the mapped thickness of the film. The local stress may be determined using Stoney's equation that is corrected for non-uniform substrate curvature, non-uniform film thickness, and non-uniform substrate thickness.