Patent ID: 7488610

Claim:
An insulator film characteristic measuring method for measuring the characteristics of an insulator film formed on a surface of a semiconductor substrate in a non-contact manner with respect to the insulator film, comprising: a surface voltage characteristic measuring step of measuring a measured surface voltage characteristic which is a surface voltage characteristic with respect to a surface charge amount of the insulator film in a non-contact manner with respect to the insulator film; a provisional setting step of provisionally setting a plurality of inner charge amounts; a theoretical surface voltage characteristic calculation step of calculating, with respect to each of the plurality of inner charge amounts provisionally set, a theoretical surface voltage characteristic which is a theoretical characteristic of the surface voltage with respect to the surface charge amount of the insulator film; a step of obtaining, with respect to each of the theoretical surface voltage characteristics, a mean value difference which is a difference between a surface voltage mean value obtained based on the measured surface voltage characteristics and a surface voltage mean value obtained based on the theoretical surface voltage characteristics, so that the mean value difference is set as a surface voltage change due to a surface adsorbed substance which is adsorbed on the insulator film surface; a step of calculating, with respect to each of the theoretical surface voltage characteristics, a deviation of the measured surface voltage characteristic with respect to a corrected surface voltage characteristic which is obtained by correcting the theoretical surface voltage characteristic according to the surface voltage change; and a minimum deviation set-point determining step of determining a set-point for the inner charge amount corresponding to the theoretical surface voltage characteristic which minimizes the deviation.