Electrical characteristics of polycrystalline silicon thin film transistors using the Cu-field aided lateral crystallization process

Polycrystalline silicon thin film transistors (poly-Si TFTs) were fabricated on glass substrate by using a concept of Cu-field aided lateral crystallization (Cu-FALC). The crystallization of a-Si was significantly enhanced when an electric field of 30 V/cm was applied to selectively Cu-deposited amorphous silicon (a-Si) film during thermal annealing at 500degreesC for 3 h. These FALC TFTs using Cu exhibited a low off-state leakage current of 6.2 X 10(-12) A at V-g = - 10 V and a maximum on/off current ratio of 3.1 X 10(5). The field-effect mobility and the threshold voltage of the fabricated poly-Si TFT were about 22.0 cm(2)/Vs and 3.9 V, respectively. Therefore, the possibility of high-performance and low-temperature (<500degreesC) poly-Si TFTs was demonstrated by using Cu-FALC technology. (C) 2002 American Vacuum Society.