GAAS HETEROEPITAXY ON AN EPITAXIAL SI SURFACE WITH A LOW-TEMPERATURE PROCESS

This letter reports the growth of an anti-phase-free GaAs layer on a ( 100) epitaxial Si substrate offset by 0.5-degrees without high-tempera ture treatment prior to growth. Atomic force microscopy shows that the epitaxial Si surface has regular steps prior to growth. The average t errace width is 25.6 nm, and the step height is calculated to be 0.22 nm from the terrace width and offset angle, which approximately corres ponds to a double atomic layer height of (100) Si of 0.27 nm. This sin gle domain structure of the epitaxial Si surface gives the heteroepita xial GaAs a high crystalline quality. Secondary ion mass spectrometry profiles show an abrupt GaAs-Si interface. Laser diodes on epitaxial S i substrates show room-temperature cw operation which confirms device applicability.