High-Electron-Mobility InN Layers Grown by Boundary-Temperature-Controlled Epitaxy

A boundary-temperature-controlled epitaxy, where the growth temperature of InN is controlled at its maximum, is used to obtain high-electron-mobility InN layers on sapphire substrates by molecular beam epitaxy. The Hall-effect measurement shows a recorded electron mobility of 3280 cm^2 V^-1 s^-1 and a residual electron concentration of 1.47×10^17 cm^-3 at room temperature. The enhanced electron mobility and reduced residual electron concentration are mainly due to the reduction of threading dislocation density. The obtained Hall mobilities are in good agreement with the theoretical modelling by the ensemble Monte Carlo simulation.