Silicon-doped InSb films of 100nm in thickness were grown by molecular-beam epitaxy on undoped low-temperature InSb buffer layers on GaAs(100) substrates. For a set of samples grown with the same Si flux, the free carrier concentration also increased with buffer thickness, and an analysis which included an estimate of the donor-doping properties of the dislocations suggested that a fraction of the Si may also be trapped at the dislocations, where it acts as an acceptor. Hall effect measurements, corrected for the effects of parallel conduction in the buffer layer, and surface depletion in the doped region, showed that the mobility of the Si-doped region improved as the buffer layer thickness increased, and reached corrected values as high as 15000cm2/Vs; approaching that of lightly compensated material. These mobility dependences were quantitatively consistent with the incorporation model.

Evidence for Dislocation-Related Amphoteric Behaviour of Si Dopant in High-Mobility InSb Thin Films. T.Zhang, J.J.Harris, S.K.Clowes, M.Debnath, A.Bennett, L.F.Cohen, T.Lyford, P.F.Fewster: Semiconductor Science and Technology, 2005, 20[12], 1153-6