RF Performance Potential of Strained-Si, In0.53Ga0.47As, and GaSb Double-Gate Ultra-Thin-Body n-FETs with Lg=10.7 nm

In this paper, using a ballistic, full-band, and atomistic simulation approach based on the nearest-neighbor tight-binding model and the Non-equilibrium Green´s Function formalism, the static and RF performance of a (100)/<;110>; strained-Si, (100)/<;100>; In_0.53Ga_0.47As, as well as (111)/<;110>; GaSb n-type double-gate ultra-thin-body FETs are analyzed and compared. All the structures are designed according to the ITRS specifications for 2020. Due to a relatively large density-of-states, but also high electron velocity, the GaSb FET represents a good compromise between the strained-Si and InGaAs devices. It exhibits therefore the highest ON-current at a given OFF-current, about 10-15% higher than strained-Si and 25-30% higher than InGaAs. However, in terms of current-gain cut-off frequency, the InGaAs FET is far ahead of its two counterparts, outperforming them by a factor of ~3.