High-performance polycrystalline silicon thin-film transistors prepared via the laser crystallization of the prepatterned channel layer on the bottom-gate structure

Abstract

High-performance polycrystalline silicon thin-film transistors (TFTs) using an excimer laser crystallization of the prepatterned channel layer on the bottom-gate (BG) structure were fabricated to exhibit a field-effect mobility as high as 339 cm(2)/V s and an on/off current ratio of 9.5x10(7) with respect to 102 cm(2)/V s and 1.5x10(7) for the conventional top-gate (TG) TFTs, respectively. Such a superior performance is attributed to the cross-shaped grain boundary structure formed in the channel region owing to the two-dimensional location control of grain boundaries. Moreover, the prepatterned BG TFTs show better device-to-device uniformity than the conventional TG ones due to the manipulated grain boundaries. This technology is thus promising for the future applications of system-on-panel and three-dimension integrated circuits. (C) 2012 Elsevier B.V. All rights reserved.