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:
Apr. 09, 2019
Filed:
Apr. 05, 2016
Ebara Corporation, Tokyo, JP;
Toshifumi Kimba, Tokyo, JP;
EBARA CORPORATION, Tokyo, JP;
Abstract
The present invention relates to a film-thickness measuring method for detecting a film thickness by analyzing optical information contained in a reflected light from a substrate. The film-thickness measuring method includes producing a spectral waveform indicating a relationship between intensity and wavelength of reflected light from a substrate; performing Fourier transform processing on the spectral waveform to determine strengths of frequency components and corresponding film thicknesses; determining local maximum values (M, M) of the strengths of the frequency components; and selecting, according to a preset selection rule, one film thickness from film thicknesses (t, t) corresponding respectively to the local maximum values (M, M). The selection rule is either to select an N-th largest film thickness or to select an N-th smallest film thickness, and N is a predetermined natural number.