MAGNETOTRANSPORT OF DELTA-DOPED IN0.57GA0.43AS ON INP(001) GROWN BETWEEN 390 AND 575-DEGREES-C BY MOLECULAR-BEAM EPITAXY

Silicon (Si) delta- (delta-) doped In0.53Ga0.47As layers were grown by molecular beam epitaxy on InP(001) substrates between 390 degrees C a nd 575 degrees C. Subbands formed at the delta layer were examined wit h Hall and Shubnikov-de Haas effect measurements in conjunction with s elf-consistent Poisson-Schrodinger modeling. Below a growth temperatur e of 525 degrees C we find good agreement with modeling, but above 525 degrees C a decrease in active doping level suggests possible surface aggregation, or reaction with impurities in the growth chamber. Signi ficant surface segregation spread of the Si is only found for growth a bove 450 degrees C. There is some evidence that DX-like centers may be present, since their incorporation improves slightly the quality of t he fits to subband occupancies. Samples grown at 390 degrees C show st rong persistent photoconductivity at low temperatures, attributed to d efect states in the InGaAs. (C) 1998 American Institute of Physics.