Dependence of defect generation and structure on interface chemistry in ZnSe/GaAs

Formation of Zn-As and Ga,Se,-like interfacial layers are suggested by transmission electron microscopy in ZnSe films grown on Zn-exposed GaAs-(2 X 4) and Se-exposed GaAs-(4 X 6) surfaces, respectively. The densities of As precipitates and extrinsic Shockley-type stacking faults in the films increase as the surface coverage of c(4 X 4) reconstruction increased on the Zn-exposed As-stabilized GaAs surfaces. On the other hand, the densities of stacking faults in ZnSe/GaAs increase as a function of Se interaction or contamination on the surfaces of the GaAs epilayers. In these samples, intrinsic Frank- and extrinsic Shockley-type stacking faults bound by anion and cation-terminated partial edge dislocations are generated, respectively.