Photoactivated high-k lanthanum oxide-aluminum oxide (La2O3–Al2O3) alloy-type gate dielectrics for low-voltage-operating flexible transistors

Low-temperature-processable gate dielectrics with high dielectric constants, low leakage current, and good electrical/mechanical stabilities are largely pursued in diverse electronics including flexible transistors, wearable sensors, integrated logic circuits, and various optoelectronic devices. Her...

Full description

Saved in:
Bibliographic Details
Published in:Journal of alloys and compounds 2020-11, Vol.842, p.155671, Article 155671
Main Authors: Kim, Jaeyoung, Kim, Minho, Kang, Youngjin, Kim, Kyung-Tae, Heo, Jae-Sang, Park, Sung Kyu, Kim, Yong-Hoon
Format: Article
Language:English
Subjects:
Alloy systems
Alloying effects
Aluminum oxide
Bend radius
Deep ultraviolet
Dielectric properties
Flexible electronics
Gallium
High-k
Indium gallium zinc oxide
Lanthanum
Lanthanum aluminum oxide
Lanthanum oxides
Leakage current
Logic circuits
Low temperature
Metal oxides
Optoelectronic devices
Oxide thin-film transistors
Permittivity
Semiconductor devices
Silicon
Substrates
Surface roughness
Thin film transistors
Threshold voltage
Transistors
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Low-temperature-processable gate dielectrics with high dielectric constants, low leakage current, and good electrical/mechanical stabilities are largely pursued in diverse electronics including flexible transistors, wearable sensors, integrated logic circuits, and various optoelectronic devices. Here, we report low-temperature photochemically activated gate dielectrics based on a lanthanum oxide-aluminum oxide (La2O3–Al2O3 or LAO) alloy system for a utilization in flexible metal-oxide thin-film transistors (TFTs). With proper alloying of La2O3 and Al2O3 at an optimal ratio, synergetic effects could be achieved from both gate dielectric materials, high dielectric constant and excellent insulating properties. With a La:Al ratio of 2:8, LAO gate dielectrics with high dielectric constant (k = 10.72), low surface roughness (0.517 nm), low leakage current density (1.7 × 10−10 A cm−2 @2 MV cm−1), and high breakdown field (∼4.8 MV cm−1) were achieved. By utilizing the photo-annealed LAO as a gate dielectric, low operating voltage (≤5 V) solution-processed indium-gallium-zinc-oxide (IGZO) TFTs having saturation mobility of 8.5 ± 3.25 cm2 V−1s−1, linear mobility of 10.8 ± 2.03 cm2 V−1s−1, subthreshold slope of 0.228 V dec−1, and on/off ratio of ∼105 are demonstrated. Furthermore, the fabricated IGZO TFTs exhibited negligible hysteresis characteristics (
ISSN:0925-8388
1873-4669
DOI:10.1016/j.jallcom.2020.155671