| 摘要 |
PURPOSE:To take a measurement without limiting the distance from the surface of the wafer by installing the optical system or optical element part of the height measuring instrument in a convergent electromagnetic field in the center of the charged beam converging lens of a charged particle beam exposing device. CONSTITUTION:The wafer height measuring instrument is provided successively to the charged particle beam exposing device which has a polarizing electrode 14 for a charged particle beam in the inside space of the cylindrical converging lens 12. Parallel irradiation light 2 from a light source 1 after being passed through a collimator 3 and a slit 4 is made parallel to the lens 12 by a reflection mirror 13g. Then, an irradiation point A on the wafer surface 6 is irradiated with the light and reflected light 7 from the point A is guided to a photodetecting element on the lens 12 through reflecting mirrors 13i and 13j. Consequently, the distance between the lens 12 and surface 16 is set freely. |
