RELAXATION IN INXGA1-XAS/INP FOR COMPRESSIVE AND TENSILE STRAIN

An X-ray diffraction investigation of strain relief in InGaAs/InP has been performed for In compositions x of 54.3% and 50.8%, corresponding to compressive and tensile strain, respectively. Strain is relieved at thicknesses well above the Matthews-Blakeslee critical thickness, leading to a small residual strain, in common with most III-V materials grown at conventional substrate temperatures. Recent X-ray photoelectron spectroscopy studies indicate that one or two monolayers of InAs may be incorporated at the interface during thermal oxide desorption in an arsenic atmosphere. Such an interfacial strained layer, if present, would lead to a shift in the observed peak position. Hence there is an uncertainty in the strain analysis for thin epilayers in the absence of detailed information about the interfacial structure.