AlGaN/GaN HEMT with 200 GHz fmax on sapphire substrate with InGaN back-barrier
最大振荡频率为200 GHz的蓝宝石衬底AlGaN/GaN HEMT

A gate-recessed AlGaN/GaN high electron mobility transistor (HEMT) on sapphire substrate having fmax of 200 GHz is reported. The gate-recessed device with a T-shaped gate exhibits a maximum drain current density of 1.1A/mm, and a peak extrinsic transconductance of 421mS/mm with minimum short-channel effects because of an InGaN back-barrier layer. A unity current gain cut off frequency(fT) of 30GHz and a maximum oscillation frequency(fmax) of 105GHz are obtained. After removing SiN by wet etching, the fT of the device increase from 30GHZ to 50GHz and the fmax increases from 105GHz to 200GHz, which result from a lower Cgs and Cgd after removing Si3N4.