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. 06, 1994
Filed:
Mar. 08, 1993
Ryo Hattori, Itami, JP;
Seizi Nishizawa, Hachioji, JP;
Tokuji Takahashi, Hachioji, JP;
Ryoichi Fukasawa, Hachioji, JP;
JASCO Corporation, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An apparatus for measuring the thickness of a semiconductor layer includes a light source emitting light; an interferometer producing modulated interference light by modulating the light from the light source; an optical system including a light transmission member for introducing the modulated interference light into a measurement sample including at least one film on a substrate; a light detecting element for detecting the modulated interference light reflected from the film and producing an output signal in response; an extracting element for extracting a film interference component having a waveform from the output signal; and an element for calculating the thickness of the film from the waveform of the output signal component. The light detecting element includes a plurality of photodetectors having respective photometric wavenumber ranges that overlap. Thereby, a wavenumber range that is the sum of the respective wavenumber ranges of the respective components is obtained and an optical measurement can be realized over a wide wavenumber range that could not be measured with a single photodetector.