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Unveiling the Role of Al 2 O 3 Interlayer in Indium–Gallium–Zinc–Oxide Transistors
Author(s) -
Kim Tae Hyeon,
Park Woojin,
Oh Seyoung,
Kim So-Young,
Yamada Naohito,
Kobayashi Hikaru,
Jang Hye Yeon,
Nam Jae Hyeon,
Habazaki Hiroki,
Lee Byoung Hun,
Cho Byungjin
Publication year - 2021
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.202000621
Subject(s) - materials science , optoelectronics , indium , transistor , thin film transistor , schottky barrier , annealing (glass) , doping , schottky diode , amorphous solid , electrode , gallium , oxide , nanotechnology , layer (electronics) , electrical engineering , diode , composite material , metallurgy , chemistry , crystallography , voltage , engineering
Although insertion of a thin insulating layer between metal electrodes and a semiconducting channel is an effective way to improve device performance, the exact reason for improvement in performance is not elucidated. Herein, the role of an Al 2 O 3 interlayer sandwiched between Al metal electrodes and an amorphous indium–gallium–zinc–oxide semiconducting channel is systematically investigated. The Al 2 O 3 interlayer results in not only a good transistor performance with increased on current but also improved gate bias stress stability. The improvement is primarily attributed to a doping effect and mitigation of interface defects. Energy‐band diagrams, experimentally obtained from temperature‐variable electrical characterization and electrostatic force microscopy, validate the channel doping effect, which increase the tunneling probability of the electron charge carriers via a reduction of the Schottky barrier width. A comprehensive study on the influence of various processing parameters, including Al 2 O 3 thickness, post‐annealing treatment conditions, and types of electrodes, on the transistor device is also performed. This approach guides the practical implementation of stable sol–gel oxide‐based thin‐film transistors and promotes integrated circuitry applications.