Patent ID: 7483147

Claim:
A method of measuring a thickness and a profile of a transparent thin film, the method acquiring information about a thickness and a profile of a thin film of a measurement object coated with the thin film, comprising: a first step of converting white light into light polarized in an arbitrary direction, and separating the polarized light into horizontally polarized light and vertically polarized light; a second step of causing one of the horizontally polarized light and the vertically polarized light to be incident on the measurement object coated with the thin film, and causing a remaining one of the vertically polarized light and the horizontally polarized light to be incident on a reference surface; a third step of generating coherent light while the light incident on the measurement object is reflected from an upper surface and a lower surface of the thin film and reflected light beams interfere with each other; a fourth step of reflecting the light incident on the reference surface to obtain reflected light, and combining the reflected light with the coherent light at the third step to generate composite coherent light; a fifth step of separating the coherent light at the third step according to frequency, and obtaining an interference pattern at each frequency; a sixth step of separating the composite coherent light at the fourth step according to frequency, and obtaining an interference pattern at each frequency; a seventh step of obtaining a phase generated by thickness of the thin film through the interference pattern at each frequency at the fifth step, and acquiring only information about a thickness of the thin film from the phase; an eighth step for obtaining a phase from the interference pattern at each frequency at the sixth step, and acquiring information about a profile of the thin film including information about a thickness of the thin film; and a ninth step of acquiring only information about the profile of the thin film from the thin film profile information including the thin film thickness information, which is acquired at the eighth step, using the thin film thickness information, which is acquired at the seventh step.