ELECTRONIC-PROPERTIES OF MULTIPLE DELTA-DOPED LAYERS IN SILICON AND GAAS

Self-consistent electronic subband structure calculations of periodic n-type delta(delta)-doped layers in Si and GaAs are performed within t he local density-functional approximation. The behavior of the energy levels, potential profiles, miniband occupancies, and Fermi level posi tion with the variation of the dopant concentration N-D and the spacin g between the delta-layers d(s) is examined for Si delta-doping in GaA s and Sb delta-doping in Si. The physical properties of these delta-do ping structures show a strong dependence on d(s), reflecting a transit ion from isolated delta-wells to superlattices as d(s) decreases. The crossover involving the change from a two-dimensional to three-dimensi onal behavior is discussed for both kinds of systems. (C) 1994 John Wi ley & Sons, Inc.