| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately and directly measure the amount of phase shift of a phase shifter layer formed on a transparent substrate in a non-contact and non-destructive manner when the phase shifter layer is formed. SOLUTION: In this method for measuring the amount of phase shift for a phase shift mask substrate wherein the phase difference of transmitted light before and after forming of a phase shifter layer on a transparent substrate at the same position of the transparent substrate, a dummy transparent substrate is mounted on a sample stage of an interferometer, on which a transparent substrate is to be mounted, instead of the transparent substrate while the phase shifter layer is formed on the transparent substrate. Phase variation of the transmitted light through the dummy transparent substrate is detected during formation of the layer, and when a phase of light passing through the transparent substrate after the phase shifter layer is formed on the transparent substrate, the mount of varied phase shift is canceled out by compensating the length of one of optical paths of the interferometer by means of an optical-path-length compensating means 11.</p> |
