標題: Surface Engineering of Polycrystalline Silicon for Long-Term Mechanical Stress Endurance Enhancement in Flexible Low Temperature Poly-Si Thin-Film Transistors
作者: Chen, Bo-Wei
Chang, Ting-Chang
Chang, Kuan-Chang
Hung, Yu-Ju
Huang, Shin-Pin
Chen, Hua-Mao
Liao, Po-Yung
Lin, Yu-Ho
Huang, Hui-Chun
Chiang, Hsiao-Cheng
Yang, Chung-I
Zheng, Yu-Zhe
Chu, Ann-Kuo
Li, Hung-Wei
Tsai, Chih-Hung
Lu, Hsueh-Hsing
Wang, Terry Tai-Jui
Chang, Tsu-Chiang
電子物理學系
光電工程學系
Department of Electrophysics
Department of Photonics
關鍵字: foldable electronics;LTPS TFTs;long-term mechanical bending;polycrystalline silicon protrusion;surface engineering
公開日期: 5-Apr-2017
摘要: The surface morphology in polycrystalline silicon (poly-Si) film is an issue regardless of whether conventional excimer laser annealing (ELA) or the newer metal-induced lateral crystallization (MILC) process is used. This paper investigates the stress distribution while undergoing longterm mechanical stress and the influence of stress on electrical characteristics. Our simulated results show that the nonuniform stress in the gate insulator is more pronounced near the polysilicon/gate insulator edge and at the two sides of the polysilicon protrusion. This stress results in defects in the gate insulator and leads to a nonuniform degradation phenomenon, which affects both the performance and the reliability in thin-film transistors (TFTs). The degree of degradation is similar regardless of bending axis (channel-length axis, channel-width axis) or bending type (compression, tension), which means that the degradation is dominated by the protrusion effects. Furthermore, by utilizing long-term electrical bias stresses after undergoing long-tern bending stress, it is apparent that the carrier injection is severe in the subchannel region, which confirms that the influence of protrusions is crucial. To eliminate the influence of surface morphology in poly-Si, three kinds of laser energy density were used during crystallization to control the protrusion height. The device with the lowest protrusions demonstrates the smallest degradation after undergoing long-term bending.
URI: http://dx.doi.org/10.1021/acsami.6b14525
http://hdl.handle.net/11536/145323
ISSN: 1944-8244
DOI: 10.1021/acsami.6b14525
期刊: ACS APPLIED MATERIALS & INTERFACES
Volume: 9
起始頁: 11942
結束頁: 11949
Appears in Collections:Articles