INVESTIGATION OF CRYSTAL QUALITY AND SURFACE-MORPHOLOGY OF ZNTE-N EPILAYERS GROWN ON ZNTE AND GASB SUBSTRATES

We investigate the crystal quality of ZnTe: N epilayers grown on ZnTe and GaSb substrates under various growth conditions using atomic force microscopy (AFM), transmission electron microscopy (TEM), and X-ray d iffraction. Due to superior crystal quality, epilayers grown on GaSb s ubstrates were of higher quality than those grown on ZnTe substrates. Hillocks, observed on the surfaces of ZnTe:N/ZnTe superlattice epilaye rs on ZnTe substrates, are the result of Te (111) fault planes emanati ng from the substrate and sets of Zn {111} twin planes originating at the superlattice interface. The number of dislocations at the GaSb sub strate/buffer interface and corresponding ZnTe:N epilayer was signific antly less than those grown on the ZnTe substrates.