Analytical Comparison of Analog/RF Performance of DG InAlGaN/GaN based MOS-HEMTsfor GaN width variation

This article investigates the effect of varying buffer layer width of underlapped double gate InAlGaN/GaN MOS-HEMT’s with Hafnium based high-k dielectric gate oxide material on its Analog/RF performance. Analog performance parameter considered in the present investigation are output current $(\mathrm{I}_{\mathrm{d}}-\mathrm{V}_{\mathrm{ds}})$; transconductance $(\mathrm{g}_{\mathrm{m}})$; transconductance generation factor (TGF); Output resistance $(\mathrm{r}_{0})$ and Intrinsic Gain $(\mathrm{g}_{\mathrm{m}}\mathrm{r}_{0})$. From the small signal model, variation in Gate to Drain Capacitance $(C_{gd})$ and Gate to Source Capacitance $(\mathrm{C}_{\mathrm{gs}})$ with frequency of operation has been considered. Further variation in Cut Off Frequency $(f_{\mathrm{T}})$ and maximum Frequency of Oscillation (f $\mathrm{fAx}_{\mathrm{MA}}$) with respect to Gate Voltage $(\mathrm{V}_{\mathrm{gs}})$ has also been considered. A comprehensiveevaluation of the Analog and RF Performances indicate that the electrical properties of the devices are largelyinfluenced by the GaN width. The device with greaterGaN width exhibits lower threshold voltage along with 11. 19% higher ON current and better gate controllability. Devices having narrowerGaN width perform optimally for a 5.37% wider range of radio frequency.