Geometric effect of nickel source on low-temperature polycrystalline silicon TFTs by metal-induced lateral crystallization

Low-temperature polycrystalline silicon thin-film transistors were fabricated by nickel-induced lateral crystallization of amorphous silicon. Line and oval-shaped nickel source patterns were compared. The oval-shaped nickel source was found to render better device performance, including lower leakage current and higher on/off current ratio. The observation is interpreted by the crystallization and nickel diffusion behavior. The oval-shaped nickel source introduces less nickel in the channels, which is the physical mechanism responsible for the improved performance.