High quality GaAs films with dislocation densities of 2–3×106 cm−2 on (100) Si substrates have been obtained by thermal cycle growth using the metalorganic chemical vapor deposition method. Significant reduction effects of dislocation density in the GaAs layers on Si have been analyzed by a simple model, in which annihilation and coalescence of dislocations are assumed to be caused by dislocation movement under thermal stress. Relaxation of thermal stress in the GaAs films on Si during thermal annealing has also been observed.

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Misfit stress dependence of dislocation density reduction in GaAs films on Si substrates grown by strainedlayer superlattices Appl.

An experimental result that the DX center appears in GaAs:Si and GaAsd:Sn under hydrostatic pressure of about 30 kbars has been obtained for the first time. This indicates clearly that the DX center in the AlGaAs alloy system is due to a substitutional donor itself (not a complex referred to as “DX”). The change in nature from the the shallow donor to the deep DX center is discussed based on the complex multivalley conduction band structure of GaAs under various pressures and of AlGaAs with various compositions.

High-quality GaAs films with a dislocation density of 2×106 cm−2 on (100) Si substrates have been obtained by thermal cycle annealing using the metalorganic chemical vapor deposition method. Dislocation behavior in GaAs/Si has been considered. Significant reduction effects of dislocation density in the GaAs layers on Si due to thermal annealing have been analyzed by a simple model, in which annihilation such as coalescence of dislocations is assumed to be caused by dislocation movement under high thermal stress and temperature. Numerical analysis suggests that excellent quality GaAs/Si films with a dislocation density of less than 105 cm−2 will be realized if thermal cycle annealing is carried out more than 1000 times without thermal degradation of the GaAs/Si.