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° without high-temperature treatment prior to growth. Atomic force microscopy shows that the epitaxial Si surface has regular steps prior to growth. The average terrace 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 corresponds to a double atomic layer height of (100) Si of 0.27 nm. This single domain structure of the epitaxial Si surface gives the heteroepitaxial GaAs a high crystalline quality. Secondary ion mass spectrometry profiles show an abrupt GaAs-Si interface. Laser diodes on epitaxial Si substrates show room-temperature cw operation which confirms device applicability.