Performance Comparison of Lattice-Matched AlInN/GaN/AlGaN/GaN Double-Channel Metal-Oxide-Semiconductor High-Electron Mobility Transistors with Planar Channel and Multiple-Mesa-Fin-Channel Array.

In this work, AlInN/GaN/AlGaN/GaN epitaxial layers used for the fabrication of double-channel metal-oxide-semiconductor high-electron mobility transistors (MOSHEMTs) were grown on silicon substrates using a metalorganic chemical vapor deposition system (MOCVD). A sheet electron density of 1.11 × 10 cm and an electron mobility of 1770 cm/V-s were obtained. Using a vapor cooling condensation system to deposit high insulating 30-nm-thick GaO film as a gate oxide layer, double-hump transconductance behaviors with associated double-hump maximum extrinsic transconductances (g) of 89.8 and 100.1 mS/mm were obtained in the double-channel planar MOSHEMTs. However, the double-channel devices with multiple-mesa-fin-channel array with a g of 148.9 mS/mm exhibited single-hump transconductance behaviors owing to the better gate control capability. Moreover, the extrinsic unit gain cutoff frequency and maximum oscillation frequency of the devices with planar channel and multiple-mesa-fin-channel array were 5.7 GHz and 10.5 GHz, and 6.5 GHz and 12.6 GHz, respectively. Hooge's coefficients of 7.50 × 10 and 6.25 × 10 were obtained for the devices with planar channel and multiple-mesa-fin-channel array operating at a frequency of 10 Hz, drain-source voltage of 1 V, and gate-source voltage of 5 V, respectively.