Enhanced drain current and cut off frequency in AlGaN/GaN HEMT with BGaN back barrier

The DC and RF capability of GaN high electron mobility transistor (HEMT) was enhanced by incoorporating BGaN back barrier (BB). Different types of back barriers like AlGaN, BGaN, AlN, AlInN, InGaN and p-diamond was used and the small and large signal RF characteristics were simulated and compared at gate length of 0.8 mu m. The AlGaN/GaN HEMT with BGaN back barrier exhibited the highest drain current density of 1.45 A/mm at drain voltage of V-D = 10 V. Also, the device with BGaN back barrier had a transconductance of 275 mS/mm at drain voltage of V-D = 10 V. The highest value of current gain cutoff frequency (f(T)) of 27 GHz was attained for HEMT with BGaN back barrier. At 100 nm gate length, the device with BGaN back barrier exhibited the highest f(T) of 118 GHz. The voltage gain of the devices is also simulated, BGaN back barrier device exhibited better performance above 12 GHz. The BGaN back barrier device exhibited better performance in terms of drain current, transconductance, current gain cut off frequency, voltage gain and linearity. Thus, the device with BGaN back barrier has a good potential for high frequency and high gain power applications that require highly linear devices.