HIGH-PERFORMANCE (F(T)SIMILAR-TO-500GHZ) IN0.52AL0.48AS IN0.53GA0.47AS/INP QUANTUM-WIRE MODFETS EMPLOYING ASYMMETRIC COUPLED-WELL CHANNELS/

A coupled-well InAlAs/InGaAs quantum wire MODFET structure is proposed , for which simulations predict improved frequency performance (>500 G Hz), over a wider range of V-g, as compared to well/wire devices with a standard MODFET heterointerface. A comparison of several transverse potential well profiles, obtained by varying the placement of a thin b arrier within a 100 Angstrom finite well, is presented. In all cases, the quantum wires consist of a 0.1 mu m long channel and a 150 Angstro m finite-square-weIl lateral profile. It has been found that the peak of the electron distribution for the first confined state, as measured from the heterointerface, changes dramatically depending on the locat ion of the thin barrier. For quantum wire structures, realized in the lattice matched system of Ino(0.52)Al(0.48)As/In(0.53)Ga(0.47)AS/InP, a change in the barrier location of 25 A is accompanied by a shift in the carrier peak of more than 40 A (similar to 20 A closer to or farth er from the spacer-well interface than in the standard MODFET profile) . Implications of this are reflected in the current-voltage characteri stics (I-d-V-d) and frequency responses (f(T)-V-g) of the proposed str uctures.