SMALL-SIGNAL ANALYSIS OF NOVEL SEMICONDUCTOR SUPERLATTICE ELECTRON-WAVE INTERFERENCE DEVICES

The linear response of a novel AlxGa1-xAs superlattice electron-wave i nterference diode (EWID) is numerically investigated using the time-de pendent Schrodinger equation. This device is based on analogies betwee n electromagnetic waves in dielectrics and quantum mechanical electron waves in semiconductors. These analogies provide a basis for a new cl ass of highly functional devices which use above-band transport. Recen t experimental results and theoretical models showed that the EWID has direct current characteristics similar to the resonant tunneling diod e. This first quantum mechanical calculation for the EWID alternating current characteristics shows that the device negative differential re sistance (NDR) persists up to about 10 THz. By examining three differe nt EWID designs, it is shown that device parameters, such as the numbe r of layers, have a strong effect on high-frequency performance. The i mportant property of NDR, combined with expected high current densitie s and possible integration with optoelectronic devices, makes the EWID a good candidate for high speed applications. (C) 1995 American Insti tute of Physics.