| 摘要 |
PURPOSE:To detect height exactly in the stage of measuring the height of an object with an optical system by irradiating light at a specified angle to the surface of the object, and providing a semiconductor position detector which has a photovoltaic effect and is formed of a uniform resistance layer on the image- forming plane of an image. CONSTITUTION:The electron ray 3 emitted from an electron ray generating source 2 is focused by an electron lens system 4 and is projected onto a material 1 to be exposed. A computer 7 and an amplifier 6 apply a pattern signal to a deflector 5. The light from a light source 8 is condensed by a lens 9 and forms a microspot at a point P. The light reflects on the surface of an exposure material 1, is focused by a lens 10 and forcuses on the detecting plane of a semiconductor position detector 11. The detector 11 generates the carrier corresponding to the quantity of light in the incident position of said light and the carrier is drawn out as output currents Ia, Ib therefrom. The currents are amplified with amplifiers 16a, 16b, and the position of the center G of gravity G in the distribution of the quantity of light is determined with an operator 17, and the height of the surface of the material is further obtained. |
