INHOMOGENEOUS AND TEMPERATURE-DEPENDENT P-INGAAS N-INP BAND-OFFSET MODIFICATION BY SILICON DELTA-DOPING - AN INTERNAL PHOTOEMISSION-STUDY/

We measured by internal photoemission the conduction-band discontinuit y Delta E(c) in p-In0.53Ga0.47As/n-InP heterojunctions with a Si delta layer (1x10(12) cm(-2)) inserted in InP at 10 Angstrom from the inter face. The n-type Si delta doping induced an inhomogeneous and temperat ure-dependent conduction-band offset reduction as revealed by two onse ts in the spectral response. The first one was absent in room-temperat ure data and was due to the Si intralayer presence. The second correla ted with the conduction-band discontinuity value for heterojunctions w ithout delta doping and its presence served as an indication of the in homogeneity of the Si delta layer. The measured value of the modificat ion was 0.11+/-0.04 eV in good agreement with the calculated one. Curr ent-voltage measurements confirmed that the Si delta layer modified th e transport parameters of the heterojunction only at low temperature. (C) 1995 American Institute of Physics.