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:
Nov. 19, 2002
Filed:
Aug. 04, 2000
Shao Yang, Superior, CO (US);
Thermo Biostar, Inc., Louisville, CO (US);
Abstract
A modified and improved polarizier ellipsometer allows for improved signal quality and signal to noise performance. This improvement is based on rotating one polarizer relative to the other fixed polarizer to generate AC mode signals related to a thin film under analysis. The AC mode signal may be compared to a background signal and the ratio of sample signal to background signal used to provide a more accurate assessment of film thickness. The normalized AC signal for an unknown thickness may be compared to a standard curve generated for a film of similar optical properties for an exact thickness determination or may be used directly to report a relative thickness value. Other modifications of the improved polarizer ellipsometer of the invention are also described where one or both of the fixed polarizers are removed to improve the signal intensity through reduction of the number of optical components. These modifications are designed to address specific thin film and substrate combinations.