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:
Aug. 22, 2000
Filed:
Feb. 05, 1999
Muneo Maeshima, Mito, JP;
Kazuo Takeda, Tokorozawa, JP;
Isao Nemoto, Hitachinaka, JP;
Shigeru Matsui, Hitachinaka, JP;
Yoshitaka Kodama, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In order to measure an inner defect of a sample with a certain high accuracy even if the sample surface of the moved up and down by flatness irregularity of the sample and problem on accuracy of the sample movement stage, incident light beams having two wavelength and respective different penetration depths for the sample are slantingly irradiated on the surface of the moving sample 15 from irradiation optical systems 4, 8, and the inner defect of the sample is measured by detecting the scattering light occurred from the interior of the sample with a detection optical system 9 arranged over the sample surface. A distance measurement means 14 is located in an upstream of a movement direction of said sample than said irradiation optical system 4, 8 and said detection optical system 9, thereby a surface height of said sample is measured. When a measured point on sample measured by the distance measurement means 14 is arrived at a lower part of the detection optical system 9, height positions of the irradiation optical system and the detection optical system are controlled by piezo electric elements 11,12,13 so that the irradiation optical system and the detection optical system are located at predetermined positions relating to the measured point.