Low-voltage Zn0.97Zr0.03O thin-film transistors incorporating high-k (Ba,Sr) TiO3 gate insulators deposited on BaRuO3(110) gate electrodes

Abstract

Low voltage of sol-gel-derived Zn0.97Zr0.03O thin-film transistors (TFTs) using (Ba,Sr)TiO3 (BST) gate insulators on BaRuO3(110), gate electrodes was investigated. Enhanced dielectric constants and suppressed leakage currents were observed in preferentially (110)-oriented BST synthesized on BaRuO3 electrodes. Compared to SiO2, BST gate dielectrics exhibited higher capacitance that led to a reduced operation voltage of 10 V. The superior interface trap density (D-it) of BST gate insulators in Zn0.97Zr0.03O-TFTs also brought about improved electrical characteristics such as mobility (mu(sat)), threshold voltage (V-th), and subthreshold slope (S) of 1.40 cm(2)/V s, 1.45 V, and 0.61 V/dec, respectively. (c) 2006 The Electrochemical Society.