Pinning Action of a Thin Ga Interfacial Layer in an Sb/Ga/GaAs Schottky Barrier Structure Grown by MBE

Abstract

AbstractThe pinning action on the barrier height of a Ga interfacial layer in an Sb/Ga/GaAs structure prepared by molecular beam epitaxy has been tracked as a function of Ga layer thicknesses for both n and p-GaAs (100). The barrier height ÆBn for n-type GaAs (ND=3×1015cm−3), determined by thermal activation measurements and capacitance measurements, changes from 0.8 to 1.0 eV as the Ga layer is increased from zero to three monolayers. The barrier height ÆBp for p-type GaAs decreases in a converse fashion so that the sum ÆBn + ÆBp is equal to the GaAs energy gap. Up to a Ga layer thickness of about one monolayer the barrier height changes are about linearly proportional to thickness.The action seen is compatible with barrier height changes that are seen when Sb/GaAs junctions are prepared with the original surface alternatively As or Ga rich and subjected to thermal annealing at temperatures up to 250°C.