First-Principles-Based Quantum Transport Simulations of High-Performance and Low-Power MOSFETs Based on Monolayer Ga₂O₃

Abstract

The electronic properties of monolayer (ML) Ga2O3 and transport properties of ML Ga2O3-based n-type metal–oxide–semiconductor field-effect transistors (MOSFETs) are investigated by first-principles calculations under the framework of density functional theory (DFT) coupled with the nonequilibrium Green’s function (NEGF) formalism. The results show that ML Ga2O3 has a quasi-direct band gap of 4.92 eV, and the x- and y-directed electron mobilities are 1210 and 816 cm2 V–1 s–1 at 300 K, respectively, under the full consideration of phonon scattering. The electron–phonon scattering mechanism shows a temperature-dependent behavior, with the acoustic modes dominating below 300 K and optical modes dominating above 300 K. At a gate length of L g = 5 nm, the on-current of ML Ga2O3 n-MOSFET for high-performance (HP) application is 2890 μA/μm, which is more than those of the most reported two-dimensional (2D) materials. The delay time as well as the power delay product of ML Ga2O3 MOSFETs can meet the demands of the latest International Technology Roadmap for Semiconductors (ITRS) for HP and low-power (LP) applications until L g is less than 4 and 5 nm, respectively. Through underlap structure and doping optimization strategies, ML Ga2O3 n-MOSFET can further fulfill the ITRS requirements for 1 nm. At last, we compare the performance of the 32-bit arithmetic logic unit (ALU) built on ML Ga2O3 MOSFETs with the recently reported beyond-CMOS devices. Our results indicate that ML Ga2O3 can serve as a promising channel material in the post-silicon era.

Discovery of Clustered-P1 Borophene and Its Application as the Lightest High-Performance Transistor

“…For 3 nm devices, the ON-to-OFF current ratio is observed to be more than 4 decades, which is remarkable. As most of the 2D material-based transistors in the literature are simulated with relaxed OFF current criteria ( I OFF = 100 nA/μm), we are able to compare our results with only a few other studies. ,− The I ON for CP1 borophene MOSFETs is well balanced compared to the transistors based on monolayer β-TeO 2 and SiP; however, the 12 nm monolayer GeC-based transistor shows comparatively balanced I ON . On the other hand, for L CH = 5 nm, I ON of CP1 borophene MOSFET is more nicely balanced than that of Zr–Zr–C–O–O and Ti–Zr–C–O–O Schottky barrier transistors.…”

“…The combined DFT-NEGF (non-equilibrium Green’s function)-based methodology, such as the one implemented in the QuantumATK package, has become prominent for exploring 2D material-based transistor characteristics. − However, this methodology can become computationally prohibitively expensive when employed with hybrid functionals such as HSE. Apart from that, the Brillouin zone of clustered-P1 borophene, shown in Figure d, is not orthogonal, and QuantumATK is not adaptable to such crystal structures.…”

p-Type High-Performance WSi2N4 MOSFETs with the Ultrashort Scale of Sub-5 nm

“…37 However, the I−V g curves of Ga 2 O 3 MOSFETs with L g = 5 nm are almost identical whether the phonon scattering is considered or not. 38 Therefore, here, we only consider ballistic transport to simulate the I−V g transfer characteristics of ML WSi 2 N 4 MOSFETs at the ultrashort scale.…”

“…For example, it was reported that the current of ML BP transistors with the 10.5 nm gate length can be up to 95% of its ballistic transport limitation . However, the I–V g curves of Ga 2 O 3 MOSFETs with L g = 5 nm are almost identical whether the phonon scattering is considered or not . Therefore, here, we only consider ballistic transport to simulate the I–V g transfer characteristics of ML WSi 2 N 4 MOSFETs at the ultrashort scale.…”

Quantum transport simulations of sub-5 nm bilayer Ga2O3 transistor for high-performance applications

“…As a representative, 2D Ga 2 O 3 has received extensive research and attention for next-generation high-performance (HP) and low-power (LP) field-effect transistors (FETs). Previous study has demonstrated that the on-current (I on ) of monolayer (ML) Ga 2 O 3 FET for HP application is as high as 2890 µA µm −1 , which is more than the most reported 2D semiconducting materials [10]. The delay time (τ ) as well as the power delay product (PDP) can meet the demands of the latest International Technology Roadmap for Semiconductors (ITRSs) for HP and LP applications, and outperform the current of Si-based FETs [10].…”