Performance and principle of operation of GaAs ballistic FET

This paper reports the first successful Monte Carlo particle simulation of submicron GaAs FETs of practical interest. The unsubstrated FET of a self-alignment type,N_{d}=7 \times 10^{16}cm^-3,L_{g}=0.25µm, and the channel thickness of 0.1µm showsI_{ds}, g_{m}, andf_{T}(=g_{m}/2πCg) of 3.3mA/20µm, 600mS/mm, and 160GHz, respectively. The FiT shows virtually no difference in the performances between 77K and 300K operations. Principle of operation of this high-performance FET has been made clear. The results on submicron GaAs FETs having 1) an undoped GaAs substrate 2) a hot-electron-injecting source structure, 3) a Permeable Base Transistor type structure, and 4) different doping densities are also reported.