CHARACTERIZATION OF ZNSE HOMO-INTERFACE GROWN BY MBE

A ZnSe home-interface, which was formed by MBE. was characterized. Fir st, when the unetched ZnSe substrates were used, 3D-nucleation occurre d, which suggested the remnant of the heterogeneous nuclei. Consequent ly, the interface layer was clearly visible and as high as 10(8) cm(-1 ) crystal defects, such as dislocations and stacking faults, were obse rved by cross sectional TEM. The EPD was uncountable at this high defe ct density. Second, when the substrates were chemically etched, 2D-nuc leation was confirmed by RHEED, and interface layer and defects were n ot observed by cross sectional TEM. However plan-view TEM and EPD reve aled that about 10(6)-10(7) cm(-2) crystal defects were observed. To c larify the origin of the crystal defects at the home-interface, SIMS a nalysis was performed and the results showed the pile up of oxygen at the interface, and the EPD was proportional to the intensity of the O signal. Finally, the reduction of the oxide layer after the chemical e tching was tried using various reagents. The reconstruction pattern of the RHEED was observed at lower temperatures using HCl solution and t he EPD was lowered near the level of the ZnSe substrates, 10(4)-10(5) cm(-2).