BEOL Compatible 15-nm Channel Length Ultrathin Indium-Tin-Oxide Transistors with Ion = 970 μA/μm and On/off Ratio Near 1011 at Vds = 0.5 V

In this paper, we report high-speed ultrathin-body (3.5 nm) indium-tin-oxide (ITO) transistors using high-k HfLaO dielectrics with a thickness of 5 nm. Because of its low dielectric constant and large bandgap, ITO is a promising channel material for scaling below the 5 nm regime for advanced low-power electronics with excellent short-channel-immunity. Here, we fabricate sub-100-nm channel length ITO transistors with ultrahigh on/off ratio near 10
¹¹
and ultralow off-state current below 10 fA/μm. The 15-nm-long ITO transistor exhibits high performance with the maximum on-state current of 970 μA/μm and peak g
_m
of 400 μS/μm at V
_ds
= 0.5 V. NAND, NOR, and SRAM based on enhancement/depletion mode (E/D) inverters have achieved full rail-to-rail output characteristics and stable memory function. Finally, We demonstrated a stage delay of 0.49 ns/stage for a 5-stage ring oscillator based on bootstrapped mode (BST) inverter, which is the best among all results based on metal-oxides transistors.