High-quality ZnSe on GaAs grown by metalorganic chemical vapor deposition (MOCVD) using diethylzinc (DEZn) and diethyselenide (DESe)

摘要

Abstract: In this work, we study the growth parameters of ZnSe on GaAs by MOCVD and characterize the epilayers by various techniques. Epilayers were grown using diethylzinc (DEZn) and diethylselenide (DESe) as source materials. Growth studies were done at 400$DGR@C under different growth conditions in an atmospheric pressure MOCVD reactor. Different DESe to DEZn ratios (from 0.5 to 5) were used to study the effects of VI/II ratio on ZnSe quality. The as-grown ZnSe epilayers were characterized by double crystal x-ray diffraction, transmission electron microscope (TEM), and scanning electron microscope. The results show excellent surface morphology and crystal quality of ZnSe. The best material was grown on undoped GaAs at the VI/II ratio near unity. The full-width-at-half-maximum of ZnSe (approximately 0.5 $mu@m thick) x-ray peak as low as 90 arc seconds was achieved. To our knowledge, this is the narrowest peak among the reported results of ZnSe on GaAs. TEM results also show very low defect density. ZnSe epilayer with low stacking faults density (less than 10$+5$//cm$+2$/) and large spacing between misfit dislocations (approximately $mu@m) were grown on GaAs. !5