INFLUENCE OF ARSENIC INCORPORATION ON SURFACE-MORPHOLOGY AND SI DOPING IN GAAS(110) HOMOEPITAXY

We have studied the relationship between the arsenic incorporation kin etics and the surface morphology and Si doping behaviour in GaAs(110) films grown by molecular beam epitaxy (MBE). The homoepitaxial growth of GaAs(110) requires low substrate temperatures and high As/Ga aux ra tios to obtain films with good surface morphology, and under these con ditions Si doped layers exhibit n-type behaviour. At higher growth tem peratures and lower As/Ga nux ratios, the epitaxial films are highly f aceted and the Si doped layers are p-type. We show that this growth re lated site switching behaviour and variation in surface morphology is due to a decrease in the As coverage arising from a small and temperat ure dependent incorporation coefficient of arsenic an this surface. (C ) 1997 Elsevier Science Ltd.