Scaled Atomic-Layer-Deposited Indium Oxide Nanometer Transistors with Maximum Drain Current Exceeding 2 A/mm at Drain Voltage of 0.7 V

TL;DR

This paper reports the development of ultra-thin indium oxide transistors with record high drain current exceeding 2 A/mm at low drain voltage, achieved through atomic layer deposition and precise channel control.

Contribution

It introduces scaled In2O3 transistors with record high drain current and demonstrates enhancement-mode operation using atomic layer deposition at nanometer scale.

Findings

Record high drain current of 2.0 A/mm at 0.7 V

Channel thickness control enables enhancement-mode operation

High density 2D channel formation explains high current density

Abstract

In this work, we demonstrate scaled back-end-of-line (BEOL) compatible indium oxide (In2O3) transistors by atomic layer deposition (ALD) with channel thickness (Tch) of 1.0-1.5 nm, channel length (Lch) down to 40 nm, and equivalent oxide thickness (EOT) of 2.1 nm, with record high drain current of 2.0 A/mm at VDS of 0.7 V among all oxide semiconductors. Enhancement-mode In2O3 transistors with ID over 1.0 A/mm at VDS of 1 V are also achieved by controlling the channel thickness down to 1.0 nm at atomic layer scale. Such high current density in a relatively low mobility amorphous oxide semiconductor is understood by the formation of high density 2D channel beyond 4E13 /cm2 at HfO2/In2O3 oxide/oxide interface.