Characterization of GaAs surfaces treated with phosphine gas photodecomposed by an ArF excimer laser

Phosphidization of GaAs surfaces is attempted with phosphine gas photodecomposed by an ArF excimer laser. Electron traps at and near the phosphidized GaAs surfaces are characterized by isothermal capacitance transient spectroscopy measurements. Phosphidization leads to a reduction 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 NL1 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 that phosphidization is effective in reducing surface states of GaAs. (C) 1998 American Institute of Physics.