GaAs p+-n+-i(υ)-n+ Tunnett Diode

The Tunnett (tunnel injection lransit lime) diode has been evaluated to be useful device in the frequency range from 100 to 1000 GHz following SIT till 100 GHz. The higher oscillation frequency with lower bias voltage and lower noise level of the Tunnett diode will be superior to those of the Impatt diode. GaAs Tunnett diodes with p⁺-n⁺-i(υ)-n⁺ structure have been fabricated by a new technique in order to overcome the low efficiency of our p⁺-n and p⁺-n-n⁺ diodes. The threshold current density (Jth) for the oscillation of the p⁺-n⁺-i(υ)-n⁺ diode has been lowered to 3.5 x 10⁴ A/cm^{2,/sup> and is half or less smaller than that of p+-n-n+ diodes. Also the sub millimeter wave fundamental oscillation as high as 300 GHz have been obtained.}