High-performance polycrystalline silicon thin-film transistors with two-dimensional location control of the grain boundary via excimer laser crystallization

J Nanosci Nanotechnol. 2012 Jul;12(7):5505-9. doi: 10.1166/jnn.2012.6308.

Abstract

High-performance low-temperature polycrystalline silicon (Poly-Si) thin-film transistors (TFTs) have been fabricated with two-dimensional (2-D) location-controlled grain boundaries using excimer laser crystallization (ELC). By locally increased thickness of the amorphous silicon (a-Si) film that was served as the seed crystals with a partial-melting crystallization scheme, the cross-shaped grain boundary structures were produced between the thicker a-Si grids. The Poly-Si TFTs with one parallel and one perpendicular grain boundary along the channel direction could therefore be fabricated to reach excellent field-effect mobility of 530 cm2/V-s while the conventional ones exhibited field-effect mobility of 198 cm2/V-s. Furthermore, the proposed TFTs achieved not only superior electric properties but also improved uniformity as compared with the conventional ones owing to the artificially controlled locations of grain boundaries.

Publication types

  • Research Support, Non-U.S. Gov't