Delta Si-doped samples were grown by means of metalorganic vapour-phase epitaxy and were studied by using capacitance-voltage and deep-level transient spectroscopic techniques. The deep level transient spectra exhibited a clear behaviour which depended upon the sheet dopant concentration (5 x 1014 to 2 x 1016/m2). Two observed peaks did not change in activation energy, with doping level, but their amplitudes increased rapidly with increased doping. They were attributed to defects which were generated by high Si concentrations, and were suggested to be related to the Ga vacancy. Another peak, in the most highly-doped samples, seemed to correspond to the DX level which was occupied near to the delta-layer. Unusual features of the EL2 level were observed in δ-doped samples, and were explained by a band-bending due to the dopant sheet.

Deep Levels in GaAs due to Si δ-Doping. P.Hubík, J.Krištofik, J.J.Mareš, J.Malý, E.Hulicius, J.Pangrác: Journal of Applied Physics, 2000, 88[11], 6488-94