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. 03, 2002
Filed:
Jul. 20, 1998
Yoshijiro Ushio, Yokohama, JP;
Takehiko Ueda, Tokyo-to, JP;
Eiji Matsukawa, Yotsukaidou, JP;
Motoo Koyama, Tokyo, JP;
Nikon Corporation, , JP;
Abstract
Apparatus and methods are disclosed that measure the thickness of a layer on a workpiece such as a semiconductor wafer, especially as the layer is undergoing a process such as polishing to achieve planarization of the layer. The apparatus comprises a probe light optical system that directs a beam of probe light to be incident on a surface of the layer, and produce a signal light from reflection of the probe light from or transmission of the probe light through the layer. A light detector retrieves and detects sufficient wavelengths of the signal light to produce a corresponding electronic signal encoding data regarding the intensity at various wavelengths of the signal light. At least one of the following is monitored: appearance or disappearance of maxima or minima in a spectrum of intensity or transmittance of the signal light, a change in wavelength at which a maximum or minimum is located in the spectrum, and change in intensity at a particular wavelength at which a maximum or minimum is located in the spectrum. The apparatus can be included with a polishing apparatus.