Charge Density Based Small Signal Modeling for InSb/AlInSb Asymmetric Double Gate Silicon Substrate HEMT for High Frequency Applications

Abstract

The Asymmetric Double Gate Silicon Substrate HEMT(ADG-Si-HEMT) is proposed in this article to analyse the carrier concentration and intrinsic small signal parameters for the heterostructure of the InSb/AlInSb silicon wafer DG-HEMT device. When the top and bottom gates are biased with different gate voltages, the HEMTs act as a three-port system and the device called Asymmetric Double Gate HEMT. The modulation of back-channel charge density due to the front gate voltage is analyzed with the position of quasi-Fermi energy levels(Ef). Also, the small signal model is obtained for various parameters like cut off frequency, gate to source capacitance and transconductance. The effects of the following parameters like delta doping, width of Silicon doping layer and various top and bottom gate voltages are analyzed to get enhanced device operation. The transconductance 2390 Sm/mm for Vfg=0.2V and cut off frequency around 197 GHz for Vbg=0.3 are obtained. All the analytical results are compared with Sentaurus 3-D TCAD simulation results. The asymmetric biasing technique offers various mixed application due to modulation in threshold voltage and modulating carrier density in dual channels.