Surface profile measuring apparatus and method

摘要

A surface profile measuring apparatus includes a reflection unit to reflect a reference beam diffracted by a first diffraction grating and cause the reflected reference beam to be incident on the first diffraction grating again, a detection unit to receive an interference beam in which the reference beam diffracted again by the first diffraction grating and a measuring beam reflected by a sample surface optically interfere with each other, and detect an interference intensity signal for each, wavelength in the interference beans, a shifting unit to shift the first diffraction grating in a direction perpendicular to a grating groove direction of the first diffraction grating, a calculation unit to calculates a phase on a basis of the interference intensity signal for each wavelength varying with a degree of shift, and a measurement unit to measure the sample surface.

主权项

1. A surface profile measuring apparatus comprising:
a light source operable to emit a light beam having a plurality of wavelengths; a splitter unit operable to split the light beam into a reference beam and a measuring beam; a first diffraction grating operable to diffract the reference beam; a reflection unit operable to reflect the reference beam diffracted by the first diffraction grating and cause the reflected reference beam to be incident on the first diffraction grating again; a detection unit operable to receive an interference beam in which the reference beam, which is incident again on the first diffraction grating and diffracted by the first diffraction grating, and the measuring beam, which is reflected by a sample surface, optically interfere with each other, and operable to detect an interference intensity signal for each wavelength in the interference beam; a plurality of parallel grating grooves provided in a surface of the first diffraction grating; a shifting unit operable to shift the first diffraction grating in a direction perpendicular to the plurality of parallel grating grooves in the first diffraction grating surface; a calculation unit operable to calculate a phase of the interference intensity signal for each wavelength in the interference beam on a basis of the interference intensity signal for each wavelength varying with a degree of shift of the first diffraction grating caused by the shifting unit; and a measurement unit operable to measure the sample surface on a basis of the phase of the interference intensity signal for each wavelength.