Magnetotransport of delta-doped In0.57Ga0.43As on InP(001) grown between 390 and 575°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 and 575 degrees C. Subbands formed at the delta layer were examined with Hall and Shubnikov-de Haas effect measurements in conjunction with self-consistent Poisson-Schrodinger modeling. Below a growth temperature 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. Significant surface segregation spread of the Si is only found for growth above 450 degrees C. There is some evidence that DX-like centers may be present, since their incorporation improves slightly the quality of the fits to subband occupancies. Samples grown at 390 degrees C show strong persistent photoconductivity at low temperatures, attributed to defect states in the InGaAs. (C) 1998 American Institute of Physics.