Effect of Schottky layer thickness on DC, RE and noise of 70-nm gate length InP HEMTs

The Schottky layer thickness of 70-nm InP HEMTs has been studied with respect to DC, RF and noise performance. An optimum gate-to-channel distance between 13-14 nm was found. Biased at a drain-to-source voltage of 0.7 V, a 2times50 mum device exhibited an extrinsic transconductance, g_m, of 1.1 mS/mm. The maximum frequency of oscillation, f_max, and the transit frequency, f_T, were extracted to 200 GHz and 170 GHz, respectively. A 50 Omega noise temperature of 140 K was measured at room temperature