DEVICE AND METHOD FOR MEASURING FILM THICKNESS OF SEMICONDUCTOR THIN FILM, SEMICONDUCTOR WAFER, AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To easily discriminate a peak for indicating the interface of a semiconductor thin film such as an epitaxial layer by correcting the position of a zero point so that the zero point of a reflection factor crosses the wave of the lowest frequency component of a reflection spectrum that is obtained by performing the Fourier transform of detection data and is located in a straight line in parallel with an abscissa. ;SOLUTION: Luminous flux entering a Michelson interferometer 8 through an aspherical mirror 7 after being emitted from a light source 6 is divided by a beam splitter 9, is reflected by a fixed mirror 10 and a traveling mirror 11, and then is synthesized for interference. Interference light with a different wavenumber is applied to a sample 13 by a mirror 12, the reflection light is detected by a detector 14, and spatial interference intensity waveform can be obtained. The obtained spatial interference intensity waveform is subjected to Fourier transform to obtain a reflection spectrum, and at the same time the zero-point position of the ordinate (reflection factor) of the reflection spectrum is corrected by a zero-point correction means. Further, by performing inverse Fourier transform using the inverse Fourier transform means, a spatial interference intensity waveform where noise has been eliminated can be obtained.;COPYRIGHT: (C)2000,JPO