High reliability in low noise InGaP gated PHEMTs

This work presents a study on the high reliability of noise characteristics of InGaP low noise PHEMTs, which was demonstrated through DC and thermal stress. The devices that we used were In/sub 0.49/Ga/sub 0.51/P/In/sub 0.15/Ga/sub 0.85/ As/GaAs low noise pseudomorphic high electron mobility transistors (PHEMTs) with the gate dimensions of 0.25 /spl times/ 160 /spl mu/m/sup 2/. The DC-stress conditions are 1) V/sub DS/ = 6V, V/sub GS/ = 0V and 2) I/sub G/ = -8 mA (50mA/mm). The ranging of thermal-stress is from 100/spl deg/C to 250/spl deg/C. The noise characteristics were measured at 12 GHz and DC bias condition is V/sub DS/ = 2V, I/sub DS/ = 10 mA. The key noise-effect parameters of devices are the deep-trap behaviour in device, source/gate resistances, gate to source capacitance and intrinsic transconductance. We showed the very small variation of minimum noise figure, NF/sub min/ and associated power gain, G/sub a/ after DC and thermal stress by explaining the variation of these key parameters to demonstrate the high reliability in InGaP low noise PHEMTs.