The Optical System Design And Experimental Study Of Precision Wafer Testing System

With the rapid development of electronic technology, and the improvement of the products` performance, the production of semiconductor chips is constantly expanding. How to detect the quality of the semiconductor chips online is an very important issue for the semiconductor production process. Beginning with principles of all kinds of optical surface testing, the article have developed a new kind of precision wafer testing system, based on polarizing interference and phase-stepping interference.Firstly, we analyzed the principles and methods of optical surface test. After studying the polarization interferometer, we established the program of the precision wafer surface testing system.Secondly, we studied the phase-stepping polarizing interference. Though the study on Wollaston prism interferometer, and comparing with the theory of birefringence crystal, we proposed a new method of light parting with parallel plane crystal replacing the Wollaston prism.Design optical path of the measure system according to the polarizing interference principle. After analyzing various influence factors of the interference fringe, the specific parameter of corresponding optic component are computed and specified. All optic component is made according these parameter, then optical experiment is set up.Finally, the whole system has been tested by a large number of experimental verification in this paper. The test results demonstrate that the optical system based on the parallel plane crystal is very effective, and can improve the precision wafer surface testing.