Sub-5-nm Ultra-thin In2O3 Transistors for High-Performance and Low-Power Electronic Applications

Ultra-thin (UT) oxide semiconductors are promising candidates for back-end-of-line (BEOL) compatible transistors and monolithic three-dimensional integration. Experimentally, UT indium oxide (In2O3) field-effect transistors (FETs) with thicknesses down to 0.4 nm exhibits extremely high drain current (10000 {\mu}A/{\mu}m) and transconductance (4000 {\mu}S/{\mu}m). Here, we employ the ab initio quantum transport simulation to investigate the performance limit of sub-5-nm gate length (Lg) UT In2O3 FET. Based on the International Technology Roadmap for Semiconductors (ITRS) criteria for high-performance (HP) devices, the scaling limit of UT In2O3 FETs can reach 2 nm in terms of on-state current, delay time, and power dissipation. The wide bandgap nature of UT In2O3 (3.15 eV) renders it a suitable candidate for ITRS low-power (LP) electronics with Lg down to 3 nm. Both the HP and LP UT In2O3 FETs exhibit superior energy-delay products as compared to other common 2D semiconductors such as monolayer MoS2 and MoTe2. Our study unveils the immense promise of UT In2O3 for both HP and LP device applications.