Reduced lattice temperature high-speed operation of pseudomorphic InGaAs/GaAs field-effect transistors

This letter presents a detailed study of the temperature dependence of submicron pseudomorphic InGaAs on GaAs substrate modulation doped field-effect transistors (MODFETs), doped-channel metal insulator field effect transistors (MISFETs), and metal semiconductor field-effect transistors (MESFETs). We determine similar variation in the measured extrinsic current gain cutoff frequency, F_T, and similar dependencies of the effective electron velocity, v_eff, with reduced lattice temperature for the different field-effect transistors. The v_eff∼T^-b where 0.15<b<0.20 over the temperature range of 300 to 110 K. These results provide direct experimental evidence that the saturated velocity of electrons is the most important parameter for high-speed operation and with proper design these different pseudomorphic InGaAs/GaAs field-effect transistors provide similar potential for high-speed operation.