Carrier concentrations and deep trap concentrations in high temperature GaAs

Abstract

The carrier concentration profiles and deep trap concentrations in molecular beam epitaxy-grown, Si-implanted, high temperature GaAs have been investigated. The samples were grown at 1023 K and the Schottky diodes were fabricated using Au contacts. The capacitance–voltage measurements were made in the temperature range 100–350 K at an interval of 2 K. The effective carrier concentration and the donor ionization energy both increased with the temperature. The energy of the carriers indicated a linear relationship, whereas the carrier concentration showed a two-step linear rise ending with a tendency to saturation at higher temperatures. The deep trap concentrations were determined from these measured values of the carrier concentration using (i) experimental data for the deep trap peaks obtained from field effect deep level transient spectroscopy measurement and (ii) the appropriate theory for the lambda effect.