Impact of Bimetal Electrodes on Dielectric Properties of TiO2 and Al-Doped TiO2 Films

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• 作者：Seong Keun Kim ; Sora Han ; Woojin Jeon ; Jung Ho Yoon ; Jeong Hwan Han ; Woongkyu Lee ; Cheol Seong Hwang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：September 26, 2012
• 年：2012
• 卷：4
• 期：9
• 页码：4726-4730
• 全文大小：259K
• 年卷期：v.4,no.9(September 26, 2012)
• ISSN：1944-8252

文摘

Rutile structured Al-doped TiO₂ (ATO) and TiO₂ films were grown on bimetal electrodes (thin Ru/thick TiN, Pt, and Ir) for high-performance capacitors. The work function of the top Ru layer decreased on TiN and increased on Pt and Ir when it was thinner than 2 nm, suggesting that the lower metal within the electrodes influences the work function of the very thin Ru layer. The use of the lower electrode with a high work function for bottom electrode eventually improves the leakage current properties of the capacitor at a very thin Ru top layer (鈮? nm) because of the increased Schottky barrier height at the interface between the dielectric and the bottom electrode. The thin Ru layer was necessary to achieve the rutile structured ATO and TiO₂ dielectric films.

Keywords:

TiO₂; bimetal layer electrode; work function