Fabrication of enhancement-mode high electron mobility transistors on AlGaN/GaN heterostructures grown on sapphire substrates is reported. These devices with 1 μm gate-length, 10 nm recessed-gate depth, 4 μm distanc...Fabrication of enhancement-mode high electron mobility transistors on AlGaN/GaN heterostructures grown on sapphire substrates is reported. These devices with 1 μm gate-length, 10 nm recessed-gate depth, 4 μm distance of source and drain ex-hibit a maximum drain current of 233 mA/mm at 1.5 V, a maximum transconduc-tance of 210 mS/mm, and a threshold voltage of 0.12 V. The threshold voltage of these devices increased to 0.53 V after 500 ℃ 5 min annealing in N2 ambient. The saturation drain current and transconductance of 15 nm recessed-gate depth re-duced compared to those of 10 nm recessed-gate depth, but the threshold voltage increased to 0.47 V. The relations between threshold voltage, controlling ability of gate and recess depth were validated by testing C-V structures on AlGaN/GaN het-erostructures with different etching depth.展开更多
An A1GaN/GaN recessed-gate MOSHEMT was fabricated on a sapphire substrate. The device, which has a gate length of 1μm and a source-drain distance of 4μm, exhibits a maximum drain current density of 684mA/mrn at Vgs ...An A1GaN/GaN recessed-gate MOSHEMT was fabricated on a sapphire substrate. The device, which has a gate length of 1μm and a source-drain distance of 4μm, exhibits a maximum drain current density of 684mA/mrn at Vgs = 4V with an extrinsic transconductance of 219 mS/mm. This is 24.3% higher than the transconductance of conventional A1GaN/GaN HEMTs. The cut-off frequency and the maximum frequency of oscillation are 9.2 GHz and 14.1 GHz, respectively. Furthermore, the gate leakage current is two orders of magnitude lower than for the conventional Schottky contact device.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 60736033)
文摘Fabrication of enhancement-mode high electron mobility transistors on AlGaN/GaN heterostructures grown on sapphire substrates is reported. These devices with 1 μm gate-length, 10 nm recessed-gate depth, 4 μm distance of source and drain ex-hibit a maximum drain current of 233 mA/mm at 1.5 V, a maximum transconduc-tance of 210 mS/mm, and a threshold voltage of 0.12 V. The threshold voltage of these devices increased to 0.53 V after 500 ℃ 5 min annealing in N2 ambient. The saturation drain current and transconductance of 15 nm recessed-gate depth re-duced compared to those of 10 nm recessed-gate depth, but the threshold voltage increased to 0.47 V. The relations between threshold voltage, controlling ability of gate and recess depth were validated by testing C-V structures on AlGaN/GaN het-erostructures with different etching depth.
基金supported by the National Natural Science Foundation of China(No.60736033)the Xi'an Applied Materials Innovation Fund(No.XA-AM-200616)
文摘An A1GaN/GaN recessed-gate MOSHEMT was fabricated on a sapphire substrate. The device, which has a gate length of 1μm and a source-drain distance of 4μm, exhibits a maximum drain current density of 684mA/mrn at Vgs = 4V with an extrinsic transconductance of 219 mS/mm. This is 24.3% higher than the transconductance of conventional A1GaN/GaN HEMTs. The cut-off frequency and the maximum frequency of oscillation are 9.2 GHz and 14.1 GHz, respectively. Furthermore, the gate leakage current is two orders of magnitude lower than for the conventional Schottky contact device.
