Enhancing Repetitive Uniaxial Mechanical Bending Endurance at = 2 mm Using an Organic Trench Structure in Foldable Low Temperature Poly-Si Thin-Film Transistors

• Published in: IEEE electron device letters Vol. 40; no. 6; pp. 913 - 916
• Main Authors: Huang, Shin-Ping, Zheng, Yu-Zhe, Chang, Ting-Chang, Chen, Bo-Wei, Chen, Po-Hsun, Chu, Ann-Kuo, Chen, Hong-Chih, Tsao, Yu-Ching, Chen, Min-Chen, Chen, Wei-Han, Wang, Terry Tai-Jui, Kanicki, Jerzy, Zhang, Sheng-Dong
• Format: Journal Article
• Language: English
• Published: IEEE 01.06.2019
• Subjects: Degradation; Flexible LTPS TFT; Insulators; Logic gates; organic trench; repetitive uniaxial mechanical bending; Stress; Substrates; Thin film transistors; Young’s modulus
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2019.2909966

At bending radius smaller than 2 mm, flexible low-temperature polycrystalline silicon thin-film transistors (LTPS TFTs) suffer from strong uniaxial mechanical stress and demonstrate severe degradation of electrical characteristics. Our previous study showed that repetitive mechanical uniaxial bending damages the gate insulator, causing carriers to trap into it. Here, degradation after channel width-axis direction bending was found to be more pronounced than after channel length-axis bending. In order to alleviate this degradation, an organic structure flexible LTPS TFT was proposed to enhance the mechanical stress endurance. After 100000 iterations of uniaxial mechanical bending at <inline-formula> <tex-math notation="LaTeX">{R} = 2 </tex-math></inline-formula> mm, degradation nearly disappeared in devices with this organic trench structure.