Electronic Properties and Ballistic Transport Performances of 2D GaO: A DFT-NEGF Study

Abstract

Integrated circuits are the physical foundation of the information society. However, with the development of Moore's law, silicon-based field-effect transistors (FETs) are approaching their physical limit. Two-dimensional (2D) materials have been classified as highly promising alternative channel materials to silicon due to their extremely thin scale, better gate control properties, and efficient avoidance of short-channel effects. Here, we study the electronic properties of the III−VI 2D semiconductor GaO and its transport properties as a channel material via ab initio simulations. The monolayer GaO has an indirect band gap of 1.57 eV and a small electron effective mass and is relatively stable. The double-gate metaloxide-semiconductor field-effect transistors (MOSFETs) with 2D GaO as the channel material can still meet the International Technology Roadmap for Semiconductor (ITRS) requirements for high-performance (HP) devices when the channel length is reduced to 4 nm. Moreover, when the channel length is 10 nm, the GaO n-MOSFET not only has a high onstate current of 3923 μA/μm but also has a low subthreshold swing (SS) of 63 mV/dec, which is close to the performance limit. Compared with devices based on other 2D materials, monolayer GaO n-MOSFETs have a smaller delay time (τ) and power-delay product. Therefore, we believe that 2D GaO is a promising channel material for future applications in electronic devices.