COMPARISION OF AlGaN/GaN AND AlGaAs/GaAs BASED HEMT DEVICE UNDER DOPING CONSIDERATION

This paper present the behaviour and characteristics of various parameters of AlGaN/GaN based HEMT under the effect of doping. The impact of n-type doping material in carrier layer of AlGaN/GaN HEMT is significantly observed on threshold voltage, transconductance, maximum drain current, cutoff frequency and capacitance. Introducing the AlGaN instead of AlGaAs produces a very significant effect: Polarization. This causes accumulation of charge carriers easily on low doping. Apart from this the effect of doping is also considered on conventional AlGaAs/GaAs based HEMT. Using this method it can be observed that for the optimum doping the behaviour AlGaN/GaN based HEMT is more useful in terms of high power, high frequency response and lower parasitic capacitance.