Determination of energy levels of surface states in GaAs metal-semiconductor field-effect transistor using deep-level transient spectroscopy

Abstract

The energy levels of surface states at the surface of GaAs were determined through capacitance deep-level transient spectroscopy of GaAs metal-semiconductor field-effect transistor with large gate periphery. Two types of hole-like traps are observed in the spectra. These originate from the surface states at the ungated regions between gate and source/drain electrodes. The activation energies of both surface states are determined to be 0.65 +/- 0.07 and 0.88 +/- 0.04 eV, which agree well with the energy levels of As-Ga(+) and As-Ga(++) within band gap of GaAs, responsible for the Fermi level pinning at the surface.