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 339cm2/Vs and an on/off current ratio of 9.5×107 with respect to 102cm2/Vs and 1.5×107 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.