Bilayer TeO₂: The First Predicted Oxide Semiconductor with Symmetric Sub-5-nm NMOS and PMOS

Wide-band-gap oxide semiconductors are very promising channel candidates for next-generation electronics due to their large-area manufacturing, high-quality dielectrics, low contact resistance, and low leakage current. However, the absence of ultrashort-gate-length (L_g) p-type transistors has restricted their application in future complementary metal oxide semiconductor (CMOS) integration. Inspired by the successfully grown high-hole-mobility bilayer (BL) β-tellurium dioxide (β-TeO₂), we investigate the performance of sub-5-nm L_g BL β-TeO₂ field-effect transistors (FETs) by utilizing first-principles quantum transport simulation. The distinctive anisotropy of BL β-TeO₂ yields different transport properties. In the y direction, both the sub-5-nm L_g n-type and p-type BL β-TeO₂ FETs can fulfill the International Technology Roadmap for Semiconductors (ITRS) criteria for high-performance (HP) devices, which are superior to the reported oxide FETs (only n-type). Remarkably, we for the first time demonstrate the existence of the NMOS and PMOS symmetry in sub-5-nm L_g oxide semiconductor FETs. As to the x direction, the n-type BL β-TeO₂ FETs satisfy both the ITRS HP and low-power (LP) requirements with L_g down to 3 nm. Consequently, our work sheds light on the tremendous prospects of BL β-TeO₂ for CMOS applications.