AlGaN/GaN HEMTs on (001) oriented silicon substrate based on 100nm SiN recessed gate technology for low cost device fabrication

This paper shows the capability of AlGaN/GaN high electron mobility transistors (HEMTs) with 0.1 mum gamma shaped gate length on (001) oriented silicon substrate for microwave power applications. The gate technology is based on silicon nitride thin film and uses a digital etching to perform the recess through the SiN mask. Output current densities of 420 mA/mm, extrinsic cut-off frequencies (fT) of 28 GHz and maximum oscillations frequencies (fmax) of 46C Hz are measured on 300 mum gate periphery device. At 2.15 GK/., an output power density of 1 W/mm associated to a power added efficiency of 17% and a linear gain of 24 dB are achieved lit VDS = 30 V and VGS = -1.2 V.