TY - JOUR
T1 - Effect of Ag doping on the performance of ZnO thin film transistor
AU - Lee, Deuk Hee
AU - Park, Ki Ho
AU - Kim, Sangsig
AU - Lee, Sang Yeol
N1 - Funding Information:
This work is supported by the Core Competency project internally funded from Korea Institute of Science and Technology (KIST) , Republic of Korea.
Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/11/30
Y1 - 2011/11/30
N2 - Ag-doped zinc oxide (SZO) thin film transistors (TFTs) have been fabricated using a back-gate structure on thermally oxidized and heavily doped p-Si (100) substrate. The SZO thin films were deposited via pulsed laser deposition (PLD) from a 1, 3, and 5 wt.% Ag-doped ZnO (1SZO, 3SZO, and 5SZO, respectively) target using a KrF excimer laser (λ, 248 nm) at oxygen pressure of 350 mTorr. The deposition carried out at both room-temperature (RT) and 200 °C. The SZO thin films had polycrystalline phase with preferred growth direction of (002) as well as a wurtzite hexagonal structure. Compare with ZnO thin films, the SZO thin films were characterized by confirming the shift of (002) peak to investigate the substitution of Ag dopants for Zn sites. The as-grown SZO TFTs deposited at RT and 200 °C showed insulator characteristics. However the SZO TFTs annealed at 500 °C showed good n-type TFT performance because Ag was diffused from Zn lattice site and bound themselves at the high temperature, and it caused generation of electron carriers. The post-annealed 5SZO TFT deposited at 500 °C exhibited a threshold voltage (Vth) of 11.5 V, a subthreshold swing (SS) of 2.59 V/decade, an acceptable mobility (μSAT) of 0.874 cm2/V s, and on-to-off current ratios (Ion/off) of 1.44 × 108.
AB - Ag-doped zinc oxide (SZO) thin film transistors (TFTs) have been fabricated using a back-gate structure on thermally oxidized and heavily doped p-Si (100) substrate. The SZO thin films were deposited via pulsed laser deposition (PLD) from a 1, 3, and 5 wt.% Ag-doped ZnO (1SZO, 3SZO, and 5SZO, respectively) target using a KrF excimer laser (λ, 248 nm) at oxygen pressure of 350 mTorr. The deposition carried out at both room-temperature (RT) and 200 °C. The SZO thin films had polycrystalline phase with preferred growth direction of (002) as well as a wurtzite hexagonal structure. Compare with ZnO thin films, the SZO thin films were characterized by confirming the shift of (002) peak to investigate the substitution of Ag dopants for Zn sites. The as-grown SZO TFTs deposited at RT and 200 °C showed insulator characteristics. However the SZO TFTs annealed at 500 °C showed good n-type TFT performance because Ag was diffused from Zn lattice site and bound themselves at the high temperature, and it caused generation of electron carriers. The post-annealed 5SZO TFT deposited at 500 °C exhibited a threshold voltage (Vth) of 11.5 V, a subthreshold swing (SS) of 2.59 V/decade, an acceptable mobility (μSAT) of 0.874 cm2/V s, and on-to-off current ratios (Ion/off) of 1.44 × 108.
KW - Ag-doped ZnO
KW - Pulsed laser deposition
KW - Thin film transistors
KW - Zinc oxide
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U2 - 10.1016/j.tsf.2011.04.064
DO - 10.1016/j.tsf.2011.04.064
M3 - Article
AN - SCOPUS:81855182112
SN - 0040-6090
VL - 520
SP - 1160
EP - 1164
JO - Thin Solid Films
JF - Thin Solid Films
IS - 3
ER -