OBSERVATION OF [100] MISFIT DISLOCATIONS IN IN0.06GA0.94AS GAAS HETEROSTRUCTURE BY SYNCHROTRON-RADIATION TOPOGRAPHY/

[100] oriented misfit dislocations in In0.06Ga0.94As/GaAs heterostruct ures with relatively low misfit f (f=0.0043) have been observed by syn chrotron radiation topography. InGaAs samples consist of 2500, 4000, a nd 6500 Angstrom thick In0.06Ga0.94As layers grown by molecular beam e pitaxy at 580 degrees C. All the topographs were taken by synchrotron radiation double crystal topography. The panchromatic cathodoluminesce nce complementary technique in the scanning electron microscope was al so applied. Misfit dislocations lying along both [100] and [110] direc tions have been observed. The dislocations parallel to [100] direction s have much lower density and extension in length than those aligned a long the [110] directions. The climb mechanism of the generation of di slocations, probably due to the high density of point defects during t he high temperature growth, is discussed. (C) 1996 American Institute of Physics.