Title: Analysis of Anomalous Capacitance Induced by TAGIDL in p-Channel LTPS TFTs
Authors: Lin, Chia-Sheng
Chen, Ying-Chung
Chang, Ting-Chang
Li, Hung-Wei
Chen, Shih-Ching
Jian, Fu-Yen
Chuang, Ying-Shao
Chen, Te-Chih
Chen, Yu-Chun
Tai, Ya-Hsiang
Department of Photonics
Institute of Display
Issue Date: 2010
Abstract: In this work, a mechanism of anomalous capacitance in p-channel low temperature polycrystalline silicon thin film transistors (LTPS TFTs) was investigated. In general, the effective capacitance of the LTPS TFTs was only dependent with the overlap area between the gate and source/drain under the off-state. However, the experimental results reveal that the off-state capacitance was increased with decreasing measurement frequency and/or with increasing measurement temperature. By fitting the curve of the drain current vs electric field under off-state region, it was verified that the trap-assisted gate-induced drain leakage (TAGIDL) consists of the Pool-Frenkel emission and thermal field emission. In addition, the charge density calculated from the C(gsd)-V(g) measurement also has the same dependence with electric field. This result demonstrates that the anomalous capacitance is mainly due to the TAGIDL. To suppress the anomalous capacitance, a band-to-band hot electron stress was utilized to reduce the vertical electric field between the gate and the drain. The electric field simulation was also performed by TCAD software. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3483759] All rights reserved.
URI: http://hdl.handle.net/11536/6171
ISSN: 0013-4651
DOI: 10.1149/1.3483759
Volume: 157
Issue: 11
Begin Page: H1003
End Page: H1007
Appears in Collections:Articles