Nanocrystalline Silicon Thin Film Transistors for High Performance Large Area Electronics

Abstract

Nanocrystalline silicon (nc-Si) thin film transistors (TFTs) have potential for high-performance applications in large area electronics, such as next generation of flat panel displays and medical xray imagers, for pixel drivers, readout circuits, as well as complementary channel logic circuits for system-on-panel integration. This potential stems from reduced threshold voltage shift and higher transconductance, compared to amorphous silicon counterpart. In this paper, we discuss various TFT structures, their associated design and performance considerations, including leakage current and threshold voltage stability mechanisms.Keywords: Thin film transistor, Nanocrystalline silicon, off current, stability Recently, nanocrystalline silicon (nc-Si) TFTs have been proposed as a low cost, high performance alternative. 4-7 They have shown effective field-effect mobilities in the range 50-100 cm 2 V -1 s -1 ; their fabrication process is fully compatible with that of a-Si:H TFTs; they have demonstrated better stability under electrical stress than a-Si:H TFTs. 4-7 Research on nc-Si TFTs is still in its infancy. It is not clear what device structure yields 297 Frontiers in Electronics Downloaded from www.worldscientific.com by MONASH UNIVERSITY on 04/22/17. For personal use only. 1056 M. R. Esmaeili-Rad et al. Frontiers in Electronics Downloaded from www.worldscientific.com by MONASH UNIVERSITY on 04/22/17. For personal use only.