Abstract:The morphology, composition and section of surface defects in HgCdTe films by liquid phase epitaxial were analyzed by means of scanning electron microscopy, energy spectrum analysis, optical profiler and metallographic microscope. The characteristics and sources of different types of surface defects are studied. The results show that the crystalline defects existing on the surface of HgCdTe films by liquid phase epitaxial are usually large or in sheet distribution, which have a significant impact on subsequent devices. By analyzing its causes, it can be found that the improvement of homogeneity of HgCdTe solution is the key to reducing such defects and improving the quality of HgCdTe films.