SURFACE SHAPE MEASURING METHOD AND DEVICE USING THE SAME

摘要

By arranging a reference surface in an inclined posture at an arbitrary angle with respect to the light advance direction, interference fringes are generated by reflected lights returning through the same optical path from the measurement surface and the reference surface. An intensity value of each pixel of the interference fringes is imaged by a CCD camera. A CPU uses the intensity value of each pixel and an intensity value of a pixel in its vicinity for each pixel to be calculated by using the expression for obtaining the interference fringes so as to obtain a phase of interference fringe waveform of each pixel and convert it into height, thereby measuring the surface shape while assuming that the DC component, the AC amplitude, and the phase of the interference fringe waveform contained in each pixel are identical.