Ultrahigh Current Vertical Channel‐All‐Around Indium–Gallium–Zinc–Oxide Field‐Effect Transistors Using Indium–Tin–Oxide Electrode with Sub‐100 nm Critical Dimension

This work investigates the effect of critical dimension (CD) scaling on the performance of vertical channel‐all‐around (CAA) indium–gallium–zinc–oxide (IGZO) field‐effect transistors (FETs) with indium–tin–oxide (ITO) as source/drain electrode and analyses their reliability. As the CD decreases, the device exhibits a normalized on‐state current ( I on ) of about 30 μA μm −1 and a subthreshold swing (SS) that remains around 100 mV dec −1 across various CDs. At the CD of 90 nm, the device achieves average values of 35.5 μA μm −1 for ultrahigh I on and 89 mV dec −1 for low SS. Furthermore, the stability of CAA IGZO FET with ITO source/drain electrode is investigated in negative bias temperature stress and positive bias temperature stress at 85 °C with 3600 s, and the Δ| V th | is less than 60 mV, demonstrating excellent reliability. The FET exhibits good thermal stability after 30 min of 300 °C annealing in an N 2 atmosphere. Finally, no significant degradation is observed after 1 × 10 11 cycles of writing and erasing, confirming the reliability of dynamic random‐access memory applications.