Wafer Surface Morphology Measurement Apparatus and Method

Abstract

This disclosure provides a wafer surface morphology measurement apparatus and method. The apparatus includes: a light source for generating a measurement beam; a projection grating for forming a measurement projection under the illumination of the measurement beam; a projection dual telecentric system for imaging the measurement projection onto a preset area of ​​the wafer surface to be measured; a detection dual telecentric system for imaging the measurement projection reflected by the wafer to be measured onto a spatial beam splitting system; the spatial beam splitting system includes multiple parallel quadrature phase gratings for splitting the measurement projection beam into four beams with the same amplitude but different phases; a data processing system for acquiring the light intensity signals of the four beams with the same amplitude but different phases, and calculating the surface height of the preset area of ​​the wafer to be measured based on the light intensity signals; and a measurement stage for placing the wafer to be measured, and sequentially moving the position of the wafer to be measured so that the data processing system obtains the surface height of the entire area of ​​the wafer surface to be measured, thus forming the surface morphology of the wafer to be measured.

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