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. 08, 1995
Filed:
Aug. 11, 1994
Masahiro Horie, Kamikyo, JP;
Dainippon Screen Mfg. Co., Ltd., Kyoto, JP;
Abstract
Spectral reflection ratios with respect to a second wavelength range are obtained and Fourier transformed to derive frequency converted spectrum. A power spectrum is obtained from the frequency converted spectrum to identify a peak which expresses interference caused by a silicon film. An approximate value d2' of the film thickness of the silicon film is calculated based on the peak position. After filtered by low-pass filtering, the frequency converted spectrum is reverse Fourier transformed to obtain spectral reflectance. From the spectral reflectance, theoretical spectral reflection ratios which are theoretically derived on only one transparent film of the thickness d3 which is formed on a silicon layer are subtracted. An approximate value d1' of the thickness of a silicon oxide film is then calculated from the spectral reflectance which are obtained by subtraction.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile