The Characteristics of n- and p-Channel Poly-Si Thin-Film Transistors with Fully Ni-Salicided S/D and Gate Structure

Abstract

n- and p-channel poly-Si thin-film transistors with fully Ni-self-aligned silicided (fully Ni-salicided) source/drain (S/D) and gate structure (n- and p-channel FUSA-TFTs) have been successfully fabricated on a 40 nm thick channel layer. The conventional poly-Si gate is replaced by the fully Ni-silicided gate, and the parasitic S/D resistance of the FUSA-TFTs is significantly reduced by the fully Ni-silicided S/D structure. The fully Ni-salicidation process is executed at a low temperature of 500 degrees C for a short rapid thermal annealing time. Experimental results show that the FUSA-TFTs give increased on/off current ratio, improved subthreshold characteristics, less threshold voltage roll-off, lower parasitic S/D resistance, higher gate capacitance, and larger field-effect mobility than conventional TFTs. The FUSA-TFTs effectively suppress the floating-body effect and parasitic bipolar junction transistor action. The characteristics of the FUSA-TFTs are suitable for three-dimensional integration applications and high performance driver circuits in the active-matrix liquid crystal displays. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3258283] All rights reserved.