A simplified model of the mechanism of dislocation reduction in epilayers grown on compliant substrates by molecular-beam epitaxy was developed, based upon dislocation theory and experiment. Theoretical results calculated with this model indicated that up to 100-fold defect reduction could be achieved by using a Si-on-insulator compliant substrate for the thick epilayer growth as compared to that of using a conventional Si substrate. The advantage of growing thick epilayers on compliant substrates could be predicted quantitatively. The mechanism of a nearly dislocation-free SiGe alloy, as well as GaAs epilayers grown on Si-on-insulator compliant substrates, was explained and the dislocation density calculated with this model was in good agreement with the present experimental results.

Mechanism of the Reduction of Dislocation Density in Epilayers Grown on Compliant Substrates. C.W.Pei, B.Turk, W.I.Wang, T.S.Kuan: Journal of Applied Physics, 2001, 90[12], 5959-62