Fabrication of InAlGaN/GaN High Electron Mobility Transistors on Sapphire Substrates by Pulsed Metal Organic Chemical Vapor Deposition

Nearly lattice-matched InAlGaN/GaN heterostructure is grown on sapphire substrates by pulsed metal organic chemical vapor deposition and excellent high electron mobility transistors are fabricated on this heterostructure. The electron mobility is 1668.08 cm^2/V\cdots together with a high two-dimensional-electron-gas density of 1.43\times10^13 cm^-2 for the InAlGaN/GaN heterostructure of 20 nm InAlGaN quaternary barrier. High electron mobility transistors with gate dimensions of 1\times50 μm^2 and 4 μm source-drain distance exhibit the maximum drain current of 763.91 mA/mm, the maximum extrinsic transconductance of 163.13 mS/mm, and current gain and maximum oscillation cutoff frequencies of 11 GHz and 21 GHz, respectively.