Microwave characterization of quarter-micron GaAs metal semiconductor field effect transistors on Si substrates

Quarter-micron gate length metal semiconductor field effect transistors (MESFETs) were fabricated in GaAs films grown on 3" Si tilted towards by 4°. De characteristics of a GaAs MESFET on Si with a 150 µm width showed an extrinsic transconductance of 360 mS/mm, and small output conductance. Extrapolation of the short-circuit current gain calculated from scattering parameters measured in the frequency range of 2 to 20 GHz yields a cutoff frequency of 55 GHz. A minimum noise figure of 2.8 dB was measured at 18 GHz which is about 1.4 dB higher than the well optimized devices on GaAs substrates.