Phase shift measuring device

Abstract

The invention provides a device for measuring the phase shift amount of a phase shift mask (15), wherein a diffraction grating (7) is provided on a single optical path from a light source (1) to an imaging device (2) for capturing a double interference image , which diffract linearly polarized light to generate multiple diffracted lights; Nomarski prism (11), which generates a laterally shifted double image of the pattern of the phase shift mask (15), and makes the pattern passing through the phase shift mask (15) The diffracted light of the part (18) and the phase shifter part (19) interferes; the moving unit (21) makes the Nomarski prism (11) slide and move along the generation direction of the double image.

Description

technical field [0001] The present invention relates to a phase shift amount measuring device for measuring the phase shift amount of a phase shift mask, in particular to a phase shift amount measuring device with simple structure and excellent temperature stability. Background technique [0002] In the conventional phase shift measurement device, before and after forming the phase shifter layer on the transparent substrate, the phase difference of the transmitted light at the same part of the transparent substrate is measured using a Mach-Zehnder interferometer, and the phase shifter layer is formed on the transparent substrate During the period, the dummy transparent substrate is placed on the sample stage of the interferometer on which the transparent substrate is placed, and the phase change of the light transmitted through the dummy transparent substrate is detected, and the phase shift after the phase shifter layer is formed on the transparent substrate is measured. Fo...

AI Technical Summary

Problems solved by technology

Therefore, it is not practical to consider the variation in the thickness of the mask for mass production

Images