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. 26, 2017
Filed:
Oct. 23, 2015
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Tsuneo Terasawa, Joetsu, JP;
Takahiro Kishita, Joetsu, JP;
Daisuke Iwai, Joetsu, JP;
Hiroshi Fukuda, Joetsu, JP;
Atsushi Yokohata, Joetsu, JP;
SHIN-ETSU CHEMICAL CO., LTD., Tokyo, JP;
Abstract
The defect size of a photomask blank is evaluated. An inspection-target photomask blank is irradiated with inspection light and reflected light of the region of the inspection-target photomask blank irradiated with the inspection light is collected through an objective lens of an inspection optical system as a magnified image of the region. Then, an intensity change part in the light intensity distribution profile of the magnified image is identified. Next, a difference in the light intensity of the intensity change part is obtained and the width of the intensity change part is obtained as the apparent width of the defect. Then, the width of the defect is calculated on the basis of a predetermined conversion expression showing the relationship among the difference in the light intensity, the apparent width of the defect, and the actual width of the defect, and the width of the defect is estimated.