CHARACTERIZATION OF GAAS-SURFACES TREATED WITH PHOSPHINE GAS PHOTODECOMPOSED BY AN ARF EXCIMER-LASER

Phosphidization of GaAs surfaces is attempted with phosphine gas photo decomposed by an ArF excimer laser. Electron traps at and near the pho sphidized GaAs surfaces are characterized by isothermal capacitance tr ansient spectroscopy measurements. Phosphidization leads to a reductio n in the trap (E-c -0.81 eV) known as an EL2, center and generation of two traps (E-c -0.24 eV and E-c -0.49 eV), which are designated as NL 1 and NL2, respectively. A significant metal work-function dependence of the barrier height is demonstrated for Schottky junctions formed on the GaAs surfaces phosphidized under optimum condition, suggesting th at phosphidization is effective in reducing surface states of GaAs. (C ) 1998 American Institute of Physics.