Characterization of ZnSe homo-interface grown by MBE

A ZnSe homo-interface, which was formed by MBE, was characterized. First, when the unetched ZnSe substrates were used, 3D-nucleation occurred, which suggested the remnant of the heterogeneous nuclei. Consequently, the interface layer was clearly visible and as high as 10’ cm-’ crystal defects, such as dislocations and stacking faults, were observed by cross sectional TEM. The EPD was uncountable at this high defect density. Second, when the substrates were chemically etched, 2D-nucleation was confirmed by RHEED, and interface layer and defects were not observed by cross sectional TEM. However plan-view TEM and EPD revealed that about 106-10’ cm-’ crystal defects were observed. To clarify the origin of the crystal defects at the homo-interface, SIMS analysis was performed and the results showed the pile up of oxygen at the interface, and the EPD was proportional to the intensity of the 0 signal. Finally, the reduction of the oxide layer after the chemical etching was tried using various reagents. The reconstruction pattern of the RHEED was observed at lower temperatures using HCl solution and the EPD was lowered near the level of the ZnSe substrates, 104-lo5 cm-*