A Nanometer-Thick Oxide Semiconductor Transistor with Ultra-High Drain Current

TL;DR

This paper demonstrates a nanometer-thick In2O3 transistor with record high drain current and transconductance, achieved through high-quality oxide interfaces and high carrier density, promising for high-performance semiconductor devices.

Contribution

The work introduces a high-performance In2O3 transistor grown by ALD at BEOL-compatible temperatures with record high drain current and transconductance, advancing ultra-thin oxide semiconductors.

Findings

Drain current exceeds 10 A/mm, 2-3 times higher than previous transistors.

Achieves a record transconductance of 4 S/mm.

High carrier density (~6-7×10^13 /cm^2) and electron velocity (~10^7 cm/s).

Abstract

High drive current is a critical performance parameter in semiconductor devices for high-speed, low-power logic applications or high-efficiency, high-power, high-speed radio frequency (RF) analog applications. In this work, we demonstrate an In2O3 transistor grown by atomic layer deposition (ALD) at back-end-of-line (BEOL) compatible temperatures with a record high drain current exceeding 10 A/mm, the performance of which is 2-3 times better than all known transistors with semiconductor channels. A record high transconductance of 4 S/mm is also achieved among all transistors with a planar structure. It is found that a high carrier density and high electron velocity both contribute to this remarkably high on-state performance in ALD In2O3 transistors, which is made possible by the high-quality oxide/oxide interface, the metal-like charge-neutrality-level (CNL) alignment, and the high band velocities induced by the low density-of-state (DOS). Experimental Hall, I-V and split C-V measurements at room temperature confirm a high carrier density up to 6-7*10^13 /cm2 and a high velocity of about 10^7 cm/s. Ultra-thin oxide semiconductors, with a CNL located deep inside the conduction band, represent a promising new direction for the search of alternative channel materials for high-performance semiconductor devices.