| 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, spectroscope 2, lenses 3a, 3b) irradiating a photomast 4 or a subject to be tested with monochromatic light as varying the wavelength in the specified range, and an imaging lens 5 forming a tested pattern image of the photomask 4, plus photoelectric converters 6, 7 detecting a light quantity on an imaging surface and a Fourier transform surface, and on the basis of a ratio of light quantities on these two surfaces, a phase variation is calculated by a computer 8.</p> |
