Fabrication of high-mobility p-channel poly-Si thin film transistors by self-aligned metal-induced lateral crystallization

High-mobility p-channel poly-Si TFTs were fabricated using a new low-temperature process (/spl les/500/spl deg/C): self-aligned metal-induced lateral crystallization (MILC). With a one-step annealing at 500/spl deg/C, activation of dopants in source/drain/gate a-Si films as well as the crystallization of channel a-Si films was achieved. The TFTs showed a threshold voltage of -1.7 V, and an on/off current ratio of /spl sim/10/sup 7/ without post-hydrogenation. The mobility was measured to be as high as 90 cm/sup 2//V/spl middot/s, which is two to three times higher than that of the poly-Si TFTs fabricated by conventional solid-phase crystallization at around 600/spl deg/C.