Epitaxial growth of GaAs on HF-treated Si substrates

Introduction of a Ga layer on an HF-treated Si substrate and its effect on the generation and behavior of dislocations in the over-grown GaAs layers are studied. There are no phases except for the crystal phase and many dislocations are observed in the lattice image at theGaAs/Si interface, although an amorphous Ga layer on the hydrogen-terminated Si is observed by RHEED before the growth of a GaAs layer. In spite of the high dislocation density at theGaAs/Si interface, the dislocation density at the GaAs surface is the same as that of conventional structures. This indicates that initial growth condition may control the formation of dislocations.