Resonant-tunneling-diode loads: speed limits and applications in fast logic circuits

It is shown that the high-speed and negative-resistance properties of the resonant tunneling diode (RTD) can improve the performance of some common inverters by greatly reducing the static power dissipation while affecting the dynamic properties to a much lesser extent. InGaAs RTDs with a peak-to-valley ratio of 12 at room temperature can switch in approximately 2 ps and, therefore, are useful as negative resistance loads for heterostructure transistors in digital circuits HFET-RTD and HBT-RTD inverter have been simulated using SPICE. The switching of the 1.0 mu m-gate-length HFT-RTD inverter is greater than that of the E-D HFET (heterostructure FET) inverter by over a factor of two, and static power is lower by a factor of five. A similar contrast is found between HBT-RTD and conventional HBT-I/sup 2/L (integrated injection logic) inverters.<>