InGaAs heteroepitaxy on GaAs compliant substrates: X-ray diffraction evidence of enhanced relaxation and improved structural quality

In0.44Ga0.56As (3% mismatch) films 3 mu m thick were grown simultaneously o n a conventional GaAs substrate, glass-bonded GaAs compliant substrates emp loying glasses of different viscosity, and a twist-bonded GaAs compliant su bstrate. High-resolution triple-crystal x-ray diffraction measurements of t he breadth of the strain distribution in the films and atomic force microsc opy measurements of the film's surface morphology were performed. The films grown on the glass-bonded compliant substrates exhibited a strain distribu tion whose breadth was narrowed by almost a factor of 2 and a surface rough ness that decreased by a factor of 4 compared to the film simultaneously gr own on the conventional substrate. These improvements in the film's structu ral quality were observed to be independent of the viscosity of the glass-b onding media over the range of viscosity investigated and were not observed to occur for the film grown on the twist-bonded substrate. (C) 1999 Americ an Institute of Physics. [S0003-6951(99)01637-X].