In situ measurement of Si-dopant concentration in GaAs during epitaxy

Abstract

Reflection high energy electron diffraction intensity oscillations are found to be shifted in phase by the predeposition of Si atoms on the (100) GaAs surface during molecular beam epitaxy. The shift is related to a change in surface reconstruction and is a linear function of the Si density. It is only observed in a narrow range of GaAs growth parameters. A different behavior is seen for (100) AlAs, which we attribute to a roughening of the growth front. The phase shift for (100) GaAs is less pronounced on the {01} streaks. This can be explained by a different surface structure near steps running along [11̄0].