RF Performance of Planar III–V Nanowire-Array Transistors Grown by Vapor–Liquid–Solid Epitaxy

The radio frequency (RF) performance of a III–V transistor comprised of nanowire (NW) high-electron mobility channels, grown by planar vapor–liquid–solid epitaxy in parallel arrays, is examined. An equivalent small-signal circuit model was used to study the contributing extrinsic and intrinsic passive elements on the NW performance as a function of bias and gate length (LG). Adequate intrinsic gain (gm/gds) ∼25 with low intrinsic (Ri) and terminal resistances (RG, RS, RD) lead to an f T /f max ∼ 30/78 GHz for LG = 150 nm and NW diameter ∼160 nm. The gate capacitance (Cg) is extracted and ∼2/3 of the total Cg is parasitic, which can be reduced with denser NW arrays. Excellent agreement between measured and modeled RF performance is achieved.