Patent ID: RE43652

Claim:
A method of controlling a processing of a substrate in a substrate processing apparatus, a surface of the substrate including a first fine structure having a pattern dimension that is smaller than a wavelength of a light beam irradiated thereon and a second fine structure having a pattern dimension that is equal to or greater than the wavelength of the irradiated light beam, the processing changing the pattern dimension of the first fine structure, the method comprising: a reflectance spectrum acquiring process of acquiring in advance a first reflectance spectrum of a reflection beam reflected from the first fine structure and a second reflectance spectrum of a reflection beam reflected from the second fine structure for each of varying pattern dimensions of the first fine structure when the pattern dimension of the first fine structure is varied; a reflectance spectrum overlapping process of acquiring reference spectrum data for each of the varying pattern dimensions of the first fine structure by overlapping the first reflectance spectrum with the second reflectance spectrum; a reflectance spectrum measurement process of actually measuring reflection beams reflected from the first and the second fine structure, respectively, after irradiating light beam on to the substrate and acquiring reflectance spectrums of the actually measured reflection beams as actually measured spectrum data; a pattern dimension acquiring process of comparing the actually measured spectrum data with the respective reference spectrum data and acquiring, as the measured pattern dimension, one of the varying pattern dimensions corresponding to reference spectrum data that is most closely matches with the actually measured spectrum data; and a substrate processing ending process of ending the processing of the substrate if the measured pattern dimension reaches a desired value, wherein the reflectance spectrum acquiring process acquires the first reflectance spectrum of the reflection beam reflected from the first fine structure by using a rigorous coupled wave analysis and the second reflectance spectrum of the reflection beam reflected from the second fine structure by using a scalar analysis.