Improvement in linearity of novel InGaAsN-based high electron mobility transistors

We have fabricated InGaAsN-based high electron mobility transistors (HEMTs) using InGaAsN as the channel layer. An extremely large gate-voltage swing (GVS) up to 4.2 V can be achieved by utilizing the large conduction band offset between the GaAs spacer layer and the InGaAsN channel layer. However, the poor channel mobility and current density as a result of nitrogen-induced electrically active defects limit the transconductance (g_m) performance. Attempts using various annealing temperatures have demonstrated that better device characteristics can be obtained via rapid thermal annealing at 700 °C. In this study, we investigate the effect of nitrogen-induced traps on the basis of Hall measurements and device characterizations of HEMTs. The improvement in GVS in the annealed samples is also discussed. Despite the relatively poor gain, InGaAsN HEMTs with excellent linearity performance after proper thermal annealing are expected to be compatible for novel InGaAsN-based optoelectronics integral circuits (OEICs).