An investigation was made of the role which was played by low-temperature growth in the reduction of threading dislocation densities in large-mismatch hetero-epitaxy. Low-temperature and high-temperature growth on highly-mismatched substrates was used to identify the mechanism of enhanced threading dislocation reduction in low (250C) temperature grown samples. The low-temperature products had equal threading dislocation sub-densities on the {111}A and {111}B planes, whereas high-temperature products had asymmetrical threading dislocation sub-densities. A model which was based upon threading dislocation reactions confirmed the beneficial effect of symmetrical threading dislocation sub-densities. A ductile-to-brittle transition was observed in the dislocation behavior at 400C.

Threading Dislocation Reduction Mechanisms in Low-Temperature Grown GaAs S.K.Mathis, X.H.Wu, A.E.Romanov, J.S.Speck: Journal of Applied Physics, 1999, 86[9], 4836-42