| 摘要 |
PROBLEM TO BE SOLVED: To precisely measure the precision of alignment by reducing the difference in contrast of images of the aligning patterns of a board and a mask. SOLUTION: The light source 11 of an inspection light generating device 10a generates an inspection light in an nonpolarized state, and a polarizing board 12 emits its S-polarization component. An inspection light irradiation device 20a converts an inspection light reflected by a half mirror 21 from an S-polarized light into a circularly polarized light by a quarter wavelength board 22, and irradiates the mask 3 and the board 1 vertically via an objective lens 30. A reflected light from the mask 3 is converted from the circularly polarized light into a P-polarized light by the wavelength board 22, and its intensity is controlled by the polarizing board 41 of a reflected light controller 40a. Scattered lights from the board 1 become in an nonpolarized state and are released from polarization. The angle of polarization of the polarizing board 41 is adjusted so that the intensity of the reflected light from the mask 3 to a detector 50 becomes in the same extent as the scattered lights from the board 1 to the detector 50. COPYRIGHT: (C)2004,JPO |
