The invention relates to a method and a device for measuring fine distribution of sample
surface shape by white-light
interferometry. The method comprises the following steps: respectively projecting a
white light beam on the surfaces of a sample and a
reference mirror; combining the reflected light beams of the two surfaces to obtain one beam, and projecting the beam on the photosensitive surface of a
CCD camera to obtain interference fringe; and changing the
pitch between the sample and an objective lens to form a plurality of interference images on the photosensitive surface, inputting the interference images into a computer to obtain the cosine distribution of
amplitude modulation signals relevant to spectral distribution of a
light source, sampling the discrete values of the plurality of
amplitude modulation signals by an unequal interval sampling method, and calculating the relative height of the sample surface. The
measurement device is composed of the
light source, a transflective spectroscope, the
CCD camera, an interference
microscope objective lens, a sample stage, etc., wherein the spectroscope divides the
light beam of the
light source into a reflective beam and a transmissive beam; the
CCD camera and the interference
microscope objective lens are respectively arranged on a transmissive
optical axis and a reflective
optical axis; the CCD camera is control-connected with a computer; and the interference
microscope objective lens can be controlled by the computer to make up-and-down movement.