High-performance poly-Si thin film transistors with highly biaxially oriented poly-Si thin films using double line beam continuous-wave laser lateral crystallization

Highly biaxially oriented poly-Si thin films were formed by double-line beam continuous-wave laser lateral crystallization (DLB-CLC). The crystallinities of the DLB-CLC poly-Si thin films were (110), (111), and (211) for the laser scan, transverse, and surface directions, respectively, and an energetically stable Sigma 3 grain boundary was observed to be dominant. All silicon grains were elongated in the laser scan direction and one-dimensionally very large silicon grains with lengths of more than 100 mu m were fabricated. Using these biaxially oriented polycrystalline silicon (polySi) films, low-temperature poly-Si TFTs (LTPS-TFTs) were fabricated at low temperatures (3 550 degrees C) by a metal gate self-aligned process. As a result, a TFT with a high electron field effect mobility of mu(FE) = 450cm(2)V(-1) s(-1) in a linear region was realized. (c) 2014 The Japan Society of Applied Physics