Atomic diffusion and surface segregation of Si in δ-doped GaAs grown by gas source molecular beam epitaxy

Abstract

We report on results that compare the planar confinement, diffusion, and surface segregation of Si δ-doped in GaAs for growth by gas source molecular-beam epitaxy and conventional molecular-beam epitaxy. For gas source molecular-beam epitaxy growth, Si diffusion versus inverse anneal temperature shows a unique two component Arrhenius form in which activation energies for diffusion differ by the fundamental GaAs band gap energy, 1.5 eV. Capacitance–voltage profiles of as-grown δ-doped Be and Si layers in GaAs produce record full width at half-maximum, 1.9 and 2.4 nm, respectively, for the gas source molecular-beam epitaxy case.