| 摘要 |
PURPOSE:To make measurement at a high speed with high accuracy and to expand the range of measurement by periodically oscillating the two mirrors of a Cassegrain optical system combined with a main mirror (concave mirror) and auxiliary mirror (convex mirror) in the directions orthogonal with each other to scan a sample surface. CONSTITUTION:A reflecting mirror 7 is inserted on the optical axis and while a sample 2 is kept monitored by a CRT 11, the sample is set in a prescribed position and thereafter, the mirror 7 is removed from the optical axis and the measurement is started. Namely, the light radiated from the sample 2 is reflected by the main mirror 3 and auxiliary mirror 4 of the Cassegrain optical system and is entered to a detector 18 via a reflecting mirror 12, a chopper 13, a cavity 15 for calibrating the sensor, a pinhole 16 and the Cassegrain optical system 17. This light is converted to an electric signal corresponding to the intensity thereof, which signal is inputted to a synchronous control mechanism 20. Respectively 50Hz and 0.5Hz signals are impressed to respective driving mechanisms 6, 5 of the auxiliary mirror 4 and the main mirror 3 from the control mechanism 20 to scan the mirror 4 and the mirror 3 respectively in the directions X, Y of the sample 2 in the case of measuring the surface of the sample 2 at, for example, 100 lines, 100 points per, line, and total 100 points. The scanning of one image plane in about 2sec is then possible.
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