10-nm Channel Length Indium-Tin-Oxide transistors with Ion = 1860 μA/μm, Gm = 1050 μS/μm at Vds = 1 V with BEOL Compatibility

In this paper, we successfully realized a shortest 10-nm channel length transistor based on ultrathin 3.5-nm indium tin oxide channel. Using 5-nm lanthanum-doped hafnium oxide (HfLaO) high- κ dielectric, the 10- nm channel ultrathin device architecture with wide bandgap exhibits excellent switching behavior with on/off ratio exceeding 10
¹⁰
and ultra-low leakage current of 40 fA/μm. Record-high on-state current of 1860 μA/μm and transconductance (g
_m
) of more than 1000 μS/μm have been achieved, benefited from a rather small contact resistance of 162 Ω·μm. R
_on
of the 10-nm ITO transistor was smaller than 500 Ω·μm. Adopting the MIT Virtual Source (MVS) model, we extracted the saturation injection velocity ν
_x0
up to 8.8 × 10
⁶
cm/s and the resulting mean free path λ
_mfp
of ITO transistor is 21.6 nm. Radio frequency transistor with 30-nm-long channel exhibited record high radio-frequency (RF) performance with small-signal current gain (f
_T
) of 20 GHz and maximum oscillation frequency (f
_max
) of 13 GHz. These two metrics contribute to √(f
_T
× f
_max
) exceeding 15 GHz, confirming overwhelming superiority compared to RF transistors based on other ultrathin novel channel materials such as MoS
₂
, BP and metal-oxides. Finally, we employed bootstrapped mode (BST) inverters to fabricate a 5-stage ring oscillator, and achieved the record-low propagation delay of 0.4 ns/stage among metal-oxides.