Patent ID: 7372582

Claim:
A method of fabricating a semiconductor device, using a plasma etching system including a vacuum chamber, a susceptor arranged in the vacuum chamber for mounting a semiconductor wafer, a gas introducing means for introducing a gas to the vacuum chamber and a means for introducing high-frequency power, the method comprising the steps of: producing plasma from the gas introduced into the vacuum chamber using the high-frequency power; forming a plurality of holes selectively on a surface of the semiconductor wafer in an atmosphere of the plasma; irradiating light having a continuous spectrum in a flat portion and a hole portion of the surface of the semiconductor wafer; measuring a relation between a first reflectivity of the light and a first wavelength of the light for the flat portion, and a relation between a second reflectivity of the light and a second wavelength of the light for the hole portion respectively; measuring the amount of shift between the first reflectivity for the flat portion and the second reflectivity for the hole portion with respect to the first and second wavelengths; and calculating the depth of the hole portion based on the shift amount of the first and second reflectivity with respect to the first and second wavelength, film thickness data and hole pattern data.