Thermal stability of pseudomorphic In/sub x/Ga/sub 1-x/As/In/sub y/Al/sub 1-y/As/InP heterostructures

The authors investigated the thermal stability of strained layers of InGaAs and InAlAs on InP. Epilayer and interface quality was assessed by high-resolution X-ray diffraction and electron mobility measurement as a function of the annealing cycle. Both techniques show that high-quality, pseudomorphic heterostructures are thermally stable at annealing temperatures of up to 700-800/spl deg/C, despite exceeding the Matthews-Blakeslee critical layer thickness. These findings suggest that layers exceeding the predicted critical thickness may be successfully used in device heterostructures.<>