位相共役波による鏡面試料上のパターン計測
1991 年 15 巻 13 号 p. 33-38
詳細
1991 年 15 巻 13 号 p. 33-38
In this paper, Efficiency of phase conjugate wavefront generation in Bi_<12>SiO_<20> crystals and application to measurement of surface defects on silicon wafer and fingerprint pattern are studied using laser beam of uniform intensity distrubution. Using the uniform laser beam. efficiency is 3〜6 times higher than when a non-uniform Ar laser of approximately gaussian intensity distribution is used. The reconstructed images of the defects and fingerprint pattern via phase conjugate wavefront generation is of high quality. It is concluded that the method is verv useful for the measurement of surface defects and fingerprint pattern.
