Electrical performance of III-V gate-all-around nanowire transistors

Abstract

The performance of III-V inversion-mode and junctionless nanowire field-effect transistors are investigated using quantum simulations and are compared with those of silicon devices. We show that at ultrascaled dimensions silicon can offer better electrical performance in terms of short-channel effects and drive current than other materials. This is explained simply by suppression of source-drain tunneling due to the higher effective mass, shorter natural length, and the higher density of states in the confined channel. We also confirm that III-V junctionless nanowire transistors are more immune to short-channel effects than conventional inversion-mode III-V nanowire field-effect transistors. (C) 2013 AIP Publishing LLC

Junctionless Silicon and In0.53Ga0.47As Transistors—Part I: Nominal Device Evaluation With Quantum Simulations

“…Quantum simulations using nonequilibrium Green's functions (NEGFs) are desirable for this purpose, given the importance of quantum mechanical effects at the nanoscale that the conventional technology computer-aided design analyses cannot capture. Existing NEGF studies of III-V JLFETs have mostly assumed ballistic transport [8], [9], with results that suggest III-V devices cannot outperform silicon due to low density of states (DOS) and poor short-channel effects (SCEs). However, ballistic transport may not be applicable in JLFETs due to strong scattering in the heavily doped channels.…”

Influence of surface stoichiometry and quantum confinement on the electronic structure of small diameter InxGa1-xAs nanowires

“…The band gap energy is an important factor in design of tunneling devices [21] and also has a significant impact on the ON-OFF current ratio in metal-oxide field effect transistors (MOSFETs) [22,23,24]. The effective masses can be considered in a first approximation as indicating the relative electron mobility for nanowires of different crystallographic orientation with a smaller effective mass suggesting higher electron mobilityassuming a similar order of magnitude in various electron relaxation processes between the various III-V nanowires examined.…”

“…On the other hand, a small effective mass is concomitant with a lower density of states (DoS) leading to a lower inversion charge density [3] for device applications. Lower inversion charge density and phenomena such as band-to-band tunneling (BTBT) can severely limit device performance for transistors operating in a ballistic regime [22,25]. In addition to tabulating the conduction band effective masses, the calculated DoS is also reported for different nanowires to allow for comparison.…”

Silicon-compatible high-hole-mobility transistor with an undoped germanium channel for low-power application

“…2(a). Although further device optimization by geometrical rendering into a fin-shaped-channel FET (FinFET), double-gate (DG) or multiple-gate (MuG) FET, a nanowire FET would produce improvements in S and DIBL, [22][23][24][25][26][27][28][29] and it is an encouraging fact that high current drivability reaching some tens of amperes per unit width has been obtained from an unaltered in-plane Ge HHMT. Figures 3(a)-3(c) illustrate the DC parameters for varying T Ge from 5 nm to 100 nm keeping the other variables constant at L G ¼ 200 nm and Al fraction ¼ 0.3.…”