The (InAs)1(GaAs)n short period superlattice (SPS) channel 2DEGFET's with 0.2 µm T-Shaped gates have been successfully fabricated on a GaAs substrate for the first time, and DC and RF performances of the superlattice channel devices have been investigated. Compared to conventional InGaAs alloy channel devices, excellent results in both DC and RF characteristics have been obtained for the SPS channel devices. The dependence of the layer index n for (InAs)1(GaAs)n on device performances has been also investigated. The (InAs)1(GaAs)4 channel samples have shown higher cut-off frequencies as well as superior noise performances compared to those for the (InAs)1(GaAs)5 channel samples. The best noise figure of 0.55 dB with an associated gain of 11.26 dB has been obtained at 12 GHz. The superior performances obtained are due to the improved electron transport properties of (InAs)1(GaAs)n SPS compared to those of InGaAs alloy. These results indicate a great potential of SPS channel structures for high frequency low noise device applications.

This paper describes an ensemble Monte Carlo simulation of Gunn domain dynamics in submicron-gate power GaAs MESFETs with a recessed gate structure. The simulated results indicate that the increase in recess width toward the drain contact region results in suppression of Gunn oscillation. This is due to the increase in domain propagation velocity by the reduced maximum electric-field in the domain. The inclusion of surface n+ region between the gate and drain regions is also proved to be effective in suppressing Gunn oscillation. Based on the simulation results, we propose a useful criterion determining whether the domain becomes traveling or stationaly. The criterion suggests that the device design allowing increased domain velocity or increased (Ndd) product is desirable for the oscillation-free, stable operation of power GaAs MESFETs.