Abstract: A technique to grow high quality and large area ZnSe layer on Si substrate is provided, comprising growing GexSi1?x/Ge epitaxial layers on Si substrate by using ultra-high vacuum chemical vapor deposition (UHVCVD), and finally growing a ZnSe film on top Ge buffer layers. Two concepts are applied in the process of this invention, the first one is to block the dislocations generated from GexSi1?x epitaxial layers and to terminate the propagated upward dislocations by using strained interfaces, accordingly the dislocation density of ZnSe layer is greatly reduced and the surface roughness is improved; the second concept is to solve the problems of anti-phase domain due to growth of polar materials on non-polar material using off-cut angle Si substrate, and that is free from diffusion problems between different atoms while generally growing ZnSe layers on Si substrate.