MEASURING INSTRUMENT FOR SURFACE SHAPE

摘要

PURPOSE:To detect a height component such as waviness and roughness of the sample surface by irradiating laser light on a sample to be measured via a couple of reflection mirrors and making the reflected light incident on top parts of beam splitting prisms and operating this based on differential output between a couple of optical detectors. CONSTITUTION:The laser light from a laser source 3 is made incident on the reflection mirror or one side of a couple of reflection mirrors 4 and irradiated on the surface of the sample 1 to be measured. The reflected laser beams are made incident on a half mirror 7 via the reflection mirror of the other side and made incident on the top part 5a' of the beam splitting prism 5a to detect an inclination of the surface in an X-Z plane of the sample 1 to be measured and the quantity of light in accordance with the displacement to the right and left is given to the optical detectors 6a and 6b. Further, the reflected laser beams are made incident on the top part 5c' of the beam splitting prism 5c to detect the inclination of the surface of in a Z-Y plane of the sample 1 to be measured and given to the optical detectors 6c and 6d. The outputs of the optical detectors 6a and 6b, and 6c and 6d are added to an amplification means 8 consisting of two couples of differential amplifiers 8a and 8b and added to an arithmetic circuit 9 consisting of integration circuits 9a and 9b.