AlGaN/GaN HEMTs on Si substrate with 7 W/mm output power density at 10 GHz

The first 10 GHz power performance of AlGaN/GaN HEMTs on silicon substrate is reported. Molecular beam epitaxy grown AlGaN/GaN heterostructure and field-plate gates with 0.3 mum length are employed to fabricate the devices on 2-inch Si (111) substrates. A maximum current density of 850 mA/mm and an extrinsic transconductance of 220 mS/mm, are achieved. Load pull measurements at 10 GHz demonstrate a continuous-wave output power density of 7 W/mm, which is the highest power density reported to date for an Si-based transistor. A peak power added efficiency of 52% is achieved for these devices at 10 GHz.