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:
Jul. 20, 2010
Filed:
Feb. 01, 2007
Paul Aoyagi, Sunnyvale, CA (US);
Leonid Poslavsky, Belmont, CA (US);
Paul Aoyagi, Sunnyvale, CA (US);
Leonid Poslavsky, Belmont, CA (US);
KLA-Tencor Corporation, Milpitas, CA (US);
Abstract
The above and other needs are met by a method of determining actual properties of a film stack by directing an incident beam of light towards the film stack, such that the incident beam of light is reflected from the film stack as a reflected beam of light. The actual properties of the reflected beam of light are measured, and properties of the film stack are estimated. A mathematical model of the film stack is solved with the estimated properties of the film stack, to yield theoretical properties of the reflected beam of light. The mathematical model is solved in part using a fast Z-matrix algorithm. The theoretical properties of the reflected beam of light are compared to the actual properties of the reflected beam of light, to yield a cost function. The estimated properties of the film stack are iteratively adjusted, and the mathematical model is iteratively solved, until the cost function is within a desired tolerance. The estimated properties of the film stack are reported as the actual properties of the film stack.