Photo mask and repair method of the same

Abstract

A light-shield film pattern and a phase shifter are formed on a transparent substrate. An applied oxide film is used as the phase shifter. On this phase shift mask, a phase shifter defect is present. On the phase shift mask containing the phase shifter defect, a silicon-containing resist is applied. At this time, the film thickness of the resist is 50 nm in the flat part. Herein, the phase shifter defect is supposed to be a bump defect. When the resist is formed in a film thickness of 50 nm, the phase difference of the light entering through the film thickness is about 30 degrees. This resist is exposed with electron beam in a region including the periphery of the defect. After electron beam exposure, it is developed. Since the silicon-containing resist is a negative resist, only the region irradiated with electron beam is left over after development. Since the resist has a mild slope, if exposed using this phase shift mask, the bump defect will not be projected. Thus, when the both sides of the bump defect are dull, if the defect height is more than the height of providing the light with a phase difference of 180 degrees, it will not be projected. When the both sides of the bump defect are moderate, the incident light also changes moderately in phase. In this case, the pattern is not projected.