| 摘要 |
<p>PURPOSE:To measure an accurate phase variation by a phase member in a phase shift photomask easily and speedily. CONSTITUTION:This tester is provided with an irradiation optical system (consisting of those of illuminant 1, an ellipsoidal mirror, mirror 3, lens 4, aperture diaphragm 5, lens 7, variable aperture diaphragm 11) irradiating a tested pattern of a photomask 8 with a monochromatic light of specified wavelength, and a photoelectric converter 10 detecting a Fourier transform image FP of the tested pattern, and on the basis of a spatial frequency coordinate position at a minimum point of the Fourier transform image FP, a phase variation is calculated by an operational means 13.</p> |
