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:
Feb. 24, 1987
Filed:
May. 10, 1985
Hidetoshi Tabata, Kawasaki, JP;
O R C Manufacturing Co., Ltd., Chofu, JP;
Abstract
An improved method of measuring film thickness of the film layer on a certain material is disclosed. The method is carried out by way of the steps of measuring reflection intensity spectrum, determining extreme values of wavelength relative to the spectrum, preparing an expected value table relative to the reflection interference orders associated with the extreme values of wavelength, calculating a group of expected values of film thickness with reference to the expected value table, calculating deviated values among the values of film thickness in association with the group of expected values, determining the expected orders which minimize absolute values corresponding to deviated values as true interference orders and determining a required film thickness with reference to the thus determined interference orders. To display wavelength scanned by a monochromator and intensity of reflected light beam transmitted from the material to be measured, an oscilloscope or a CRT is used in operative association with the monochromator. The monochromator is equipped with a diffraction grating which serves to generate marker signals having a predetermined step wavelength.