Improvement of GaAs MESFET performance using surface p-layer doping(SPD) technique

The development of a surface p-layer doping (SPD) technique to improve GaAs MESFET performance is presented. Very shallow p-type doping into the gate-drain and gate-source regions is used to improve the output conductance of the device. It is found that the threshold voltage is independent of the SPD dose. The transconductance degrades significantly as the p doping (Be, 10 keV) increases above 3×10 ¹²/cm². However, the output conductance and subthreshold current are improved with higher SPD dose. The gate-source reverse breakdown voltage is improved by about 90%, and the parasitic resistance increases by about 30% with an SPD of 5×10¹²/cm²