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:
May. 24, 2011
Filed:
Nov. 30, 2009
Phillip Walsh, Austin, TX (US);
Phillip Walsh, Austin, TX (US);
Jordan Valley Semiconductors Ltd., Migdal Haemer, IL;
Abstract
A method and apparatus is disclosed for measuring properties of an unknown sample. A reflectometer and one or more reference pieces is provided. A set of data is collected from the unknown sample and a combination of the reference pieces. A combination of the sample and reference piece data independent of incident intensity is used to determine a property of the unknown sample without calibrating incident reflectometer intensity. The method and apparatus disclosed can measure properties of thin films or scattering structures on semiconductor work pieces. In one embodiment the reflectometer utilizes vacuum ultraviolet (VUV) wavelength reflectometry. Multiple relative reflectance measurements are used to overcome effects of the inevitable contamination buildup that occurs when using optical systems in the VUV region. While advantageous for VUV wavelengths, the method described herein is generally applicable to any wavelength range, and is advantageous in situations where stable reference samples are not available.