Enhanced green laser activation by antireflective gate structures in panel transistors

Abstract

Antireflective gate structures of polycrystalline silicon (poly-Si) and silicon dioxide films enable postimplantation green continuous-wave laser annealing of all Si regions of green laser-crystallized panel Si transistors. About 40% of the incident laser-energy penetrates to the channels, owing to antireflective gate structures with the absorptive gate poly-Si, while 65% of the incident laser-energy enters the source/drain regions because of Fresnel reflections at the air/source (drain) interfaces. Such inverted laser-energy profiles and ascendant defect distributions along the channels/junctions/contact regions, yielded continuous, improved epilike Si microstructures over the entire active layer. The electron mobility of the transistors, 620 cm(2)/V s, approaches that of integrated-circuits transistors. (C) 2008 American Institute of Physics.