We have investigated the effect of a thin low-temperature-grown ZnSe (LT-ZnSe) buffer layer in improving ZnSe crystallinity by inserting it between the high-temperature-grown ZnSe epilayer and the GaAs substrate. In particular, the density of stacking fault defects, which is normally observed in ZnSe-based films grown on GaAs substrate, can be well reduced by inserting a thin LT-ZnSe buffer layer. A ZnSe film with stacking fault densities as low as similar to5.4 x 10(4)/cm(2) was obtained by growing on Zn exposed (2 x 4) As-stabilized surfaces of GaAs buffer layer with LT-ZnSe buffer, in contrast, similar to7 x 10(8)/cm(2) was obtained by directly growing on GaAs substrate, that is, without Zn exposure, LT-ZnSe. and GaAs buffer layers. (C) 2004 American Vacuum Society.