Cat-CVD SiN-passivated AlGaN-GaNHFETs with thin and high al composition barrier layers

The effect of SiN surface passivation by catalytic chemical vapor deposition (Cat-CVD) on Al0.4Ga0.6N-GaN heterostructure field-effect transistors (HFETs) was investigated. The channel sheet resistance was reduced by the passivation due to an increase in electron density, and the device characteristics of the thin-barrier HFETs were significantly improved by the reduction of source and drain resistances. The AlGaN(8 nm)-AlN(1.3 nm)-GaN HFET device with a source/drain distance of 3 mum and a gate length of 1 um had a maximum drain current density of 0.83 Mum at a gate bias of +1.5 V and an extrinsic maximum transconductance of 403 mS/mm. These results indicate the substantial potential of Cat-CVD SiN-passivated AlGaN-GaN HFETs with thin and high Al composition barrier layers.