A comparative study of the Raman spectra of ZnSe films grown by molecular beam epitaxy on GaAs(100) substrates passivated byNH4)2)SxandS2Cl2solutions is presented. Based on the analysis of the line shape of the first‐order longitudinal‐optical phonon of ZnSe with spatial correlation model of Raman scattering, it is shown that the ZnSe films grown on the GaAs substrates passivated byS2Cl2solutions have longer coherence lengths, which indicate that their crystalline qualities are better than those passivated byNH4)2Sxsolutions. In addition, the barrier heights of ZnSe/GaAs interfaces for different S passivations have been obtained from the ratios of the intensity of the coupled longitudinal‐optical phonon‐plasmon mode to that of the longitudinal‐optical mode of GaAs Raman peak. The results show that the ZnSe/GaAs samples passivated byS2Cl2solutions have lower density of interfacial states. ©1995 American Institute of Physics.