Low-leakage current polysilicon TFTs for LCD pixel addressing

The leakage current characteristics of low-temperature polysilicon TFTs (thin-film transistors) below 450 degrees C have been investigated. It was confirmed that the laser-induced crystallized polysilicon with temperature below 450 degrees C has good physical properties and device characteristics in TFT, equal to those of polysilicon with a process temperature of around 600 degrees C. Reduction of leakage current at higher signal voltage could be achieved by the optimization of the geometrical structure with the laser-induced crystallized polysilicon TFT. The low leakage current characteristics at the higher signal voltage may enlarge the applicable field in the higher-performance display. For example, these improved characteristics make it possible to apply higher voltage for addressing pixels of normally white TN and LC (liquid crystal) polymer composite mode. >