Patent ID: 8071397
Filing Date: 2011-12-06
Classification: H01J,H01L

Abstract:
1. A method of fabricating a semiconductor in which a semiconductor wafer having an undercoating layer film and an upper layer film disposed thereon is located within a chamber and both the films constitutes a surface of the semiconductor wafer and the upper layer film is etched by using plasma generated within the chamber, the undercoating layer film and the upper layer film being made of different materials to each other, the method comprising: detecting an intensity of interference light of a plurality of different wavelengths as to each of the wavelengths, during a predetermined time period for an etching process, the interference light being obtained from a surface of the wafer including the undercoating layer film and the upper layer film; detecting an amount of the intensity of the interference light according to a progress of the etching process of the upper layer film obtained during the predetermined time period by using the plurality of different wavelengths of the interference light as a parameter; and determining a thickness of the undercoating layer film based on a specific wavelength of the interference light detected by the detector as to which time differential values of the intensity of the interference light of the plurality of different wavelengths in the predetermined time period changes in a widely fluctuating manner.