P-23: Effect of Buffer Layers on Performance and Reliability of Polycrystalline Silicon TFTs Fabricated on Polyimide

Thickness of buffer layers affects performance of flexible polycrystalline silicon thin film transistors (TFT). A thicker buffer SiO 2 film demonstrates better endurance to thermal expansion stress from the polyimide substrate. However, the thickness of buffer SiO 2 film would causes the variation of optimal excimer laser annealing (ELA) crystallization condition. In addition, the simulation results shows that the non‐uniform stress in the gate insulator is more pronounced near the poly‐silicon/gate insulator edge and at the two sides of the poly‐silicon protrusion. It would affect the stability results and device performance. By optimization the process condition, the device would still have good device performance after operating under high temperature (60 □) and long period of time (500hrs).