Patent ID: 8384888

Claim:
A mask defect measurement method for measuring a shape of a phase defect existing on an exposure mask, comprising: previously deriving an angular range in which width of a scattering area on the phase defect is predictable within an angular range in which inspection light having a desired wavelength incident on the mask is scattered by the phase defect on the mask and measuring intensity of light scattered in the angular range, calculating a radius of the phase defect based on the measured scattered light intensity by using a previously set relational expression, changing the angular range of scattered light to be measured and remeasuring scattered light intensity in the changed angular range, calculating a scattering cross-sectional area based on the remeasured scattered light intensity by using a relational expression of the predetermined scattered light intensities and scattering cross-sectional areas, repeatedly performing a process of remeasuring the scattered light intensity and calculating the scattering cross-sectional area until the remeasured scattered light intensity is saturated, and determining a shape of the phase defect on the mask by using the calculated radius of the phase defect and each of the calculated scattering cross-sectional areas according to a predetermined phase defect shape model.