학술논문
First Demonstration of Highly Scaled Atomic Layer Deposited Ultrathin InSnZnO Channel Thin Film Transistor Exhibiting Superior Electrical Characteristics
Document Type
Conference
Author
Source
2023 International Electron Devices Meeting (IEDM) Electron Devices Meeting (IEDM), 2023 International. :1-4 Dec, 2023
Subject
Language
ISSN
2156-017X
Abstract
In this study, we reported the employment of atomic-layer-deposited (ALD) ultrathin (~1.8 nm) amorphous InSnZnO (a-ITZO) as an innovative channel material to develop the back-end-of-line (BEOL) compatible thin film transistor (TFT) for monolithic 3D integration for the first time. By carefully adjusting the In/Sn/Zn ratio through ALD cycles, the bottom gate (BG) TFT with ALD In0.83Sn 0.11 Zn 0.06 O channel and channel length (L ch ) of 40 nm demonstrates remarkably optimized performance characteristics, including positive threshold voltage (V th ) of 0.38 V, excellent subthreshold swings (SS) value of 66.4 mV/dec, and high electron mobility (μEE) of 48 cm2/V-s. Moreover, the maximum on-state current density (ION) of 686 μA/μm at VDS=2V and impressively low drain-induced barrier lowering (DIBL) performance of 22 mV/V were exhibited. These results are among the most competitive values reported for TFTs based on quaternary ultrathin (Tch < 5 nm) amorphous oxide semiconductors. Furthermore, the TFT demonstrates highly stable device characteristics, as evidenced by threshold voltage shift (ΔV th ) of -40 mV and 60 mV (L ch = 700 nm) after 3600 seconds of negative gate bias stress (NBS) and positive gate bias stress (PBS) with |VG-V th | of 3 V.