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:
Dec. 18, 2018
Filed:
Mar. 17, 2017
Disco Corporation, Tokyo, JP;
Naoya Sukegawa, Tokyo, JP;
Seiji Harada, Tokyo, JP;
Disco Corporation, Tokyo, JP;
Abstract
A workpiece evaluating method evaluates the gettering property of a device wafer having a plurality of devices formed on the front side of the wafer and having a gettering layer formed inside the wafer. The method includes the steps of applying excitation light for exciting a carrier to the wafer, applying microwaves to a light applied area where the excitation light is applied and also to an area other than the light applied area, measuring the intensity of the microwaves reflected from the light applied area and from the area other than the light applied area, subtracting the intensity of the microwaves reflected from the area other than the light applied area from the intensity of the microwaves reflected from the light applied area to thereby obtain a differential signal, and determining the gettering property of the gettering layer according to the intensity of the differential signal obtained above.