Surfactant effects associated with te-doped InPAs alloys

We examine the effects of heavy Te doping on strain-relaxed InPAs alloys grown on InP using metal-organic chemical vapor deposition. Compared to Si doping, Te doping of InPAs substantially reduces film roughness at high dopant concentrations (similar to 1x10(19) cm(-3)). Unlike similar Si concentrations, high Te concentrations also suppress the incorporation of As into InPAs. An analysis of depth profiles of Te, As, and P from secondary-ion mass spectrometry further reveals the segregation of 0.6 ML of Te on the InPAs surface during growth. We infer that surfactant effects produced by the segregated Te cause the observed changes in surface morphology and As incorporation. (c) 2007 American Institute of Physics.