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:
Jun. 14, 1994
Filed:
Jul. 20, 1992
Applicant:
Inventors:
Susumu Kuwabara, Annaka, JP;
Takao Abe, Annaka, JP;
Assignee:
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
25033901 ; 356244 ;
Abstract
A method for evaluating the surface state of a silicon wafer is here disclosed which comprises the steps of directly bringing an internal reflection element having a larger refractive index than that of silicon into close contact with the surface of the silicon wafer, selecting a light source having a wave length range which compounds present on the surface can absorb, entering light having a larger incident angle than critical angle from the light source into the element, and then evaluating a chemical bond state on the surface containing impurities or impure atoms by means of a multi-reflection method.