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:
Oct. 13, 2020
Filed:
Dec. 10, 2019
Lasertec Corporation, Yokohama, JP;
LASERTEC CORPORATION, Yokohama, JP;
Abstract
A mask inspection apparatus according to the present disclosure includes: a field stop unit capable of switching between a field stop for an optical mask configured to emit an incident illumination light while maintaining the polarization state thereof and a field stop for an EUV mask configured to change the polarization state of a part of the incident illumination light and to cause an illumination light including an S-polarized light and a P-polarized light; a beam splitter unit capable of switching between a PBS for an optical mask and a non-polarized BS; an objective lens configured to collect an illumination light reflected in the beam splitter unit in a mask to be inspected and collect a reflected light obtained by reflecting an illumination light in the mask to be inspected; and a λ/4 plate that can be provided in an optical path of an illumination light and a reflected light.