"Surface exchange" doping of MBE GaAs from S and Se "captive sources"

Abstract

Lead was not detectably incorporated in GaAs during MBE growth above 480°C, and films grown under massive fluxes of lead show no degradation of material properties. This effect was utilized in the "surface exchange" n-type doping of GaAs with S and Se using PbS and PbSe as captive sources. The processes were shown to be efficient and able to produce relatively uncompensated material. 150-Å-wide spikes in doping could be easily produced, indicating a very low surface rate limitation to incorporation.