FILM THICKNESS MEASURING INSTRUMENT

摘要

PROBLEM TO BE SOLVED: To provide a film thickness measuring instrument which can limit a measurement area on the surface of a sample at need without specially decreasing the diameter of an incident beam. SOLUTION: The film thickness measuring instrument equipped with an incidence optical system which irradiates the surface of the sample with polarized light and a detection optical system which outputs data regarding the sample surface according to the quantity of polarization variation of elliptic polarized light reflected by the sample surface is provided with a pinhole part for limiting a photodetection area between an analyzer and a spectroscope of the detection optical system.