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Low‐Voltage MgZnO Thin Film Transistors with an Amorphous Al 2 O 3 Gate Insulator Grown by Pulsed Laser Deposition
Author(s) -
Wang ChangPeng,
Tang Dan,
Han Shun,
Cao PeiJiang,
Liu XinKe,
Zeng YuXiang,
Liu WenJun,
Jia Fang,
Xu WangYing,
Zhu DeLiang,
Lu YouMing
Publication year - 2018
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.201700821
Subject(s) - materials science , thin film transistor , amorphous solid , pulsed laser deposition , optoelectronics , threshold voltage , thin film , gate dielectric , dielectric , layer (electronics) , transistor , electrical engineering , nanotechnology , voltage , crystallography , chemistry , engineering
In this paper, MgZnO thin‐film transistors (TFTs) is fabricated using amorphous Al 2 O 3 as the gate dielectric layer by pulsed laser deposition (PLD). The electrical performance of MgZnO‐TFTs based on a channel layer grown at 300 °C shows saturation mobilities (µ sat ) of ≈6.70 cm 2 V −1 s −1 , threshold voltages ( V T ) of ≈0.70 V, a subthreshold swing ( SS ) of ≈0.138 V dec −1 , and an I on / I off ratio of 10 6 . The threshold voltage and the subthreshold swing of the devices is greatly reduced compared to some previous reports for MgZnO‐TFTs. The quality of the Al 2 O 3 gate insulator deposited under different oxygen pressures is investigated. The results shows that the crystallinity of the Al 2 O 3 thin film decreases with increasing oxygen pressures from 0.01 to 5 Pa until an amorphous Al 2 O 3 thin film is obtained at 5 Pa. The MgZnO active layer grown on the amorphous Al 2 O 3 thin film has the best crystal quality with the smallest number of defects. Our research demonstrates that an amorphous Al 2 O 3 thin film is a promising gate dielectric candidate for high‐performance oxide TFTs.