OFF-State-Stress-Induced Instability in Switching Polycrystalline Silicon Thin-Film Transistors and Its Improvement by a Bridged-Grain Structure

In this letter, an off-state stress is proposed to simulate the operation conditions of switching polycrystalline thin-film transistors in active-matrix displays for the first time. A dynamic hot carrier (HC) effect, dependent on data pulse falling time, dominates the device degradation. Incorporated with the transient simulations, the device degradation mechanism is tentatively discussed. Finally, a bridged-grain structure, which can effectively shares the stress voltage drop via multiple reverse junctions, is employed to relieve such off-state-stress-induced dynamic HC degradation.