Characteristics of poly-si thin film transistors with highly biaxially oriented linearly arranged poly-si thin films using double line beam continuous-wave laser lateral crystallization

Highly biaxially oriented linearly arranged poly-Si thin films were formed by double-line beam continuous-wave laser lateral crystallization (DLB-CLC). Crystallinities of the poly-Si thin films were (110), (111), and (211) for the laser scan, transverse, and surface directions, respectively, and an energetically stable σ3 grain boundary was dominantly observed. Silicon grains were elongated along the laser scan direction and one-dimensionally very large silicon grains with lengths of more than 100 μm were formed. High-performance low-temperature poly-Si thin film transistors (TFTs) using these poly-Si thin films were fabricated at low-temperatures (≤550°C) by a metal gate self-aligned process and a TFT with a high electron field effect mobility of μ_FE= 560 cm₂V_-1s_-1 in a linear region was realized. Also, electron field effect mobility variation of below 10% was obtained at the same crystallization region. Leakage current mechanism was also investigated by temperature dependence of the TFT characteristics.