Fabrication of poly-Si TFT's on glass with a novel method of back-reflecting low-temperature UV-assisted nickel-induced crystallization

An ultraviolet-assisted Ni-induced crystallization technique is used to grow polysilicon films on glass at temperatures as low as 380 degreesC. The silicon films grown using this method are suitable for the fabrication of thin film transistors on ordinary glass. Samples prepared, consist of 1500 Angstrom of silicon film deposited on 1000 Angstrom silicon nitride and 2000 Angstrom of chromium layers, which acts as a reflecting layer to increase UV photon absorption in silicon film. A thin layer of nickel silicide is used as the nucleation seed. Annealing is performed in the presence of an ultraviolet exposure with intensity of 15 mW/cm(2), leading to a high crystallinity of silicon film as examined by SEM and X-ray diffraction. The lateral growth as the main feature of this technique is monitored using optical microscopy and investigated using XRD and SEM analyses. Crystallographic etchants such as Seeco and Sirtl are also used to reveal the crystal orientation of the film. Preliminary results of transistor fabrication on ordinary glass are reported indicating a hole mobility of 50 cm(2)/Vs. (C) 2002 Elsevier Science Ltd. All rights reserved.