Abstract :
The high-frequency performances-cutoff frequency fT , maximum oscillation frequency fmax, and so on-for a superconducting base transistor using high-Tc materials are evaluated. Calculations are based on a number of key assumptions, summarized as follows: (1) The quasiparticle density of state in high-Tc oxide superconductors and tunneling between the emitter and base superconductors can be expressed in terms of conventional theories, (2) The barrier height of the Schottky junction between the base superconductor and the collector semiconductor is equal to the gap energy Δ(T) of the base superconductor, (3) Critical temperature Tc=90 K, superconductor energy gap at zero kelvin Δ(0)=30 meV, carrier concentration n=1021 cm-3, resistivity ρ=100 μΩcm, magnetic penetration depth λ=0.1 μm, and effective mass m=5 m0 in the emitter and base superconductors. Calculated results reveal that high-Tc superconducting base transistors have a potential for much higher high-frequency performance values than conventional devices. For example, typical fT, fmax, and switching energy values are estimated to be 1 THz, 1 THz, and 10-20 J/gate, respectively
Keywords :
Schottky effect; high-temperature superconductors; penetration depth (superconductivity); superconducting junction devices; superconductive tunnelling; 30 meV; 90 K; Schottky junction; base superconductor; carrier concentration; collector semiconductor; cutoff frequency; effective mass; gap energy; high-Tc materials; high-frequency performances; magnetic penetration depth; maximum oscillation frequency; quasiparticle density; resistivity; superconducting base transistor; superconductor energy gap; switching energy values; tunneling; Conductivity; Effective mass; Frequency; Kelvin; Magnetic tunneling; Performance evaluation; Superconducting magnets; Superconducting materials; Superconductivity; Temperature;
