EFFECTS OF GROWTH TEMPERATURE ON HIGHLY MISMATCHED INAS GROWN ON GAASSUBSTRATES BY MBE

InAs layers were grown on GaAs by molecular beam epitaxy (MBE) at subs trate temperature 450 and 480 degrees C, and the surface morphology wa s studied with scanning electron microscopy (SEM). We have observed a high density of hexagonal deep pits for samples grown at 450 degrees C , however, the samples grown at 480 degrees C have smooth surface. The difference of morphology can be explained by different migration of c ations which is temperature dependent. Cross-sectional transmission el ectron microscopy (XTEM) studies showed that the growth temperature al so affect the distributions of threading dislocations in InAs layers b ecause the motion of dislocations is kinetically limited at lower temp erature. (C) 1998 Elsevier Science B.V. All rights reserved.