Significant Reduction of Dynamic Negative Bias Stress-Induced Degradation in Bridged-Grain Poly-Si TFTs

The device degradation of bridged-grain (BG) polycrystalline silicon thin-film transistors under dynamic negative bias stress (NBS) is investigated for the first time. By employing a BG structure in the active channel, dynamic NBS-induced hot carrier degradation could be significantly reduced from -99.9% to -2.4% (10
⁴
s dynamic NBS), which is attributed to a sharing of the lateral electric field across the multiple p-n junctions inherent in the structure. The nonequilibrium junction degradation model is employed and developed, incorporated with TCAD simulations.