Low-temperature poly-Si TFTs of metal source and drain using blue-laser-diode annealing (BLDA)

Blue-laser-diode annealing (BLDA) in the continuous wave mode was performed for sputtered silicon (Si) films. Polycrystalline silicon (poly-Si) thin-film transistors (TFTs) were fabricated on a glass substrate. For the source and drain formation, titanium (Ti) was evaporated to make the metal directly contact the channel Si film without adopting n+ doping. The improvement of the drain current was confirmed after hydrogen annealing at 400°C, and the typical poly-Si TFT characteristic with 50 cm2/Vs deduced effective carrier mobility was successfully observed. As the low-cost TFT fabrication without ion implantation becomes feasible, the low-temperature fabrication of poly-Si TFTs using BLDA is expected.