High-transconductance GaN MODFETs

Current-voltage (I-V) characteristics of both normally-on and normally-off AlGaN-GaN MODFETs have been presented. The sheet carrier concentration of GaN used for the fabrication of these devices is significantly high. Both normally-on and normally-off devices exhibit high transconductance g/sub m/. For normally-on devices with 4 /spl mu/m gate length, g/sub m/=72 mS/mm at T=300 K; for normally-off devices with 3 /spl mu/ gate length g/sub m/=120 mS/mm at T=300 K. The devices were observed to operate at high temperatures up to T=300/spl deg/C.