可撓式金屬氧化薄膜電晶體在彎曲應力下的電性探討及改善

Abstract

在研究中我們嘗試探討InGaZnO4的薄膜電晶體於軟性基板上彎曲時的電性變化，並嘗試由減少薄膜與薄膜之間的方式來改善及穩定電晶體的特性。實驗中，嘗試使用低楊式係數PVP並改善其特性來當作薄膜電絕緣層，以InGaZnO4作為主動層後彎曲量測電性；將電晶體由平坦彎至曲率半徑為10 mm，可發現臨界電壓及次臨界擺幅漸增，載子遷移率逐漸下降，而當曲率半徑為10mm時，薄膜電晶體因為應力的破壞而毀損而失去薄膜電晶體特性；藉由加上較厚的薄膜，我們將主動層設計於應力平衡位置以減少應力的破壞，再量測彎曲電性可以發現，因為應力的減少而讓彎曲時的電性能有穩定的表現，保有TFT的特性表現。

This study investigated the bending characteristics of amorphous oxide thin-film transistors (TFTs) with polymer dielectrics on the flexible stainless steel substrate. To raise the dielectric constant, the high-κnanoparticles was blended with polymer dielectric layer. The resulting composite dielectric layer was able to improve the TFT performance. The TFT characteristics, however, failed under bending tests at the 10 mm curvature. To reduce the bending stress effect, a thick passivation layer was applied to cover the TFTs. The transfer characteristic of the passivation layer covered TFT was preserved at the 10 mm bending curvature. The results fitted the prediction of Stoney formula.