標題: Electrical properties of low-temperature-compatible p-channel polycrystalline-silicon TFTs using high-kappa gate dielectrics
作者: Yang, Ming-Jui
Chien, Chao-Hsin
Lu, Yi-Hsien
Shen, Chih-Yen
Huang, Tiao-Yuan
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
關鍵字: hafnium silicate (HfSiOx);high dielectric constant (high-kappa);negative bias temperature instability (NBTI);polycrystalline-silicon thin-film transistors (poly-Si TFTs)
公開日期: 1-Apr-2008
摘要: In this paper, we describe a systematic study of the electrical properties of low-temperature-compatible p-channel polycrystalline-silicon thin-film transistors (poly-Si TFTs) using HfO2 and HfSiOx high-kappa gate dielectrics. Because of their larger gate capacitance density, the TFTs containing the high-kappa gate dielectrics exhibited superior device performance in terms of higher I-on/I-off current ratios, lower subthreshold swings (SSs), and lower threshold voltages (V-th), relative to conventional deposited-SiO2, albeit with slightly higher OFF-state currents. The TFTs incorporating HfSiOx as the gate dielectric had ca. 1.73 times the mobility (mu(FE)) relative to that of the deposited-SiO2 TFTs; in contrast, the HfO2 TFTs exhibited inferior mobility. We investigated the mechanism for the mobility degradation in these HfO2 TFTs. The immunity of the HfSiOx TFTs was better than that of the HfO2 TFTs-in terms of their V-th shift, SS degradation, mu(FE) degradation, and drive current deterioration-against negative bias temperature instability stressing. Thus, we believe that HfSiOx, rather than HfO2, is a potential candidate for use as a gate-dielectric material in future high-performance poly-Si TFTs.
URI: http://dx.doi.org/10.1109/TED.2008.916759
http://hdl.handle.net/11536/9487
ISSN: 0018-9383
DOI: 10.1109/TED.2008.916759
期刊: IEEE TRANSACTIONS ON ELECTRON DEVICES
Volume: 55
Issue: 4
起始頁: 1027
結束頁: 1034
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