A compact CV model for 120nm AlGaN/GaN HEMT with modified field dependent mobility for high frequency applications
We present a theoretical model of AlGaN/GaN high electron mobility transistor (HEMT) that includes the effect of spontaneous and piezoelectric polarization. Present model also incorporates the effect of mole fraction dependent mobility, saturation velocity and the accurate 2-DEG density in HEMT as a function of gate voltage in subthreshold, linear and saturation regimes. This paper reports a detailed 2-D analysis of capacitancevoltage (CV) characteristics. The contribution of various capacitances including fringing field capacitance on the performance of the device is also shown. The model further predicts the transconductance, drain conductance and frequency of operation and is in close proximity with the experimental data which confirms the validity of proposed model.
transconductance heterostructure algan/gan modfet drain current cutoff frequency