PURPOSE: To measure the position with few errors by adding coloring material which is made of an optical absorbent with respect to measuring beams of light to a resist or selecting a wavelength of the measuring beams of light so the the resist itself is made of the absorbent.
CONSTITUTION: With respect to the resist 15 formed on a silicon wafer 4 as a substrate, absorbent coloring material 14 of LED light, for example, the material containing 3% of aluminum-chloro-phthalocyanine is used. Since the incident light 13a on the inside of the resist 15 is attenuated when the measuring beams of light 13 are irradiated on the coloring material 14, the reflected light 13b reflected on the resist surface is detected with a photodetecting element without receiving the interference of the incident light 13a. Accordingly, the measuring error can be reduced. Moreover, a reflection from the resist 15 and the substrate interface can be efficiently prevented by setting the measuring beams of light to the wavelength 450W200nm without letting the coloring material enter into the resist 15 and attenuating the measuring beams of light in the resist 15.
NAKASE MAKOTO
SATO TAKASHI
