Behavior of Electron Traps in Phosphidized GaAs by Nitrogen Plasma Treatment

GaAs is treated with remote PH 3 and N 2 plasmas. Electron traps induced by plasma treatments are investigated by isothermal capacitance transient spectroscopy measurements. PH 3 plasma process generates the T P trap ( E C -0.26 eV), while N 2 plasma process produces the T N trap ( E C -0.66 eV). It is found that the T P trap is changed to the T PN3 trap with an energy level as shallow as 0.16 eV below the conduction band edge and a capture cross section as small as 1.8×10 -21 cm 2 by treating with N 2 plasma subsequently after PH 3 plasma treatment.