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http://dx.doi.org/10.6117/kmeps.2021.28.3.033

Mechanical Property Evaluation of Dielectric Thin Films for Flexible Displays using Organic Nano-Support-Layer  

Oh, Seung Jin (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST))
Ma, Boo Soo (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST))
Yang, Chanhee (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST))
Song, Myoung (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST))
Kim, Taek-Soo (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST))
Publication Information
Journal of the Microelectronics and Packaging Society / v.28, no.3, 2021 , pp. 33-38 More about this Journal
Abstract
Recently, rollable and foldable displays are attracting great attention in the flexible display market due to their excellent form factor. To predict and prevent the mechanical failure of the display panels, it is essential to accurately understand the mechanical properties of brittle SiNx thin films, which have been used as an insulating film in flexible displays. In this study, tensile properties of the ~130 nm- and ~320 nm-thick SiNx thin films were successfully measured by coating a ~190 nm-thick organic nano-support-layer (PMMA, PS, P3HT) on the fragile SiNx thin films and stretching the films as a bilayer state. Young's modulus values of the ~130 nm and ~320 nm SiNx thin films fabricated through the controlled chamber pressure and deposition power (A: 1250 mTorr, 450 W/B: 1000 mTorr, 600 W/C: 750 mTorr, 700 W) were calculated as A: 76.6±3.5, B: 85.8±4.6, C: 117.4±6.5 GPa and A: 100.1±12.9, B: 117.9±9.7, C: 159.6 GPa, respectively. As a result, Young's modulus of ~320 nm SiNx thin films fabricated through the same deposition condition increased compared to the ~130 nm SiNx thin films. The tensile testing method using the organic nano-support-layer was effective in the precise measurement of the mechanical properties of the brittle thin films. The method developed in this study can contribute to the robust design of the rollable and foldable displays by enabling quantitative measurement of mechanical properties of fragile thin films for flexible displays.
Keywords
Bilayer; Mechanical Property; Silicon Nitride; Tensile Test; Thin Film;
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