Investigation of DC and RF Performance of Novel MOSHEMT on Silicon Substrate for Future Submillimetre Wave Applications

Abstract

In this work, the DC and RF performance of a 20 nm gate length novel metal oxide semiconductor high electron mobility transistor (MOSHEMT) on Silicon substrate is studied using Sentaurus TCAD tool. The proposed MOSHEMT device features a novel T-gate structure, heavily doped In_0.52Ga_0.48As source/drain regions, delta doped planes on both sides of the In_0.75Ga_0.25As/InAs/In_0.75Ga_0.25As composite channel, a multi layer cap and a very thin layer of HfO₂ as gate dielectric. The TCAD simulation results obtained at room temperature using hydrodynamic carrier transport model indicates that the 20 nm gate length proposed MOSHEMT device is capable of providing a peak drain current of 2450 mA/mm at V_DS = 0.6 V and the peak transconductance obtained for the proposed device is 2900 mS/mm. The f_T and f_max obtained for the L_g = 20 nm proposed MOSHEMT on Silicon substrate are 372 and 480 GHz respectively. At 300 K, the measured Hall mobility of the electrons in the quantum well channel is 9600 cm²/(V s). The on state resistance (R_ON) obtained for the L_g = 20 nm proposed device is 116 Ohm μm. These devices are undoubtedly, the most suitable candidates for future sub millimetre wave applications.