Sol–gel ZrO₂ and ZrO₂–Al₂O₃ nanocrystalline thin films on Si as high-k dielectrics

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• 作者：P. Vitanov ; A. Harizanova ; T. Ivanova ; Ch. Trapalis ; N. Todorova
• 关键词：Aluminium oxide ; Sol– ; gel processing ; Electrical properties ; XRD
• 刊名：Materials Science and Engineering: B
• 出版年：2009
• 出版时间：15 December 2009
• 年：2009
• 卷：165
• 期：3
• 页码：178-181
• 全文大小：602 K

文摘

Currently, the conventional dielectric, SiO₂ or SiON is being replaced by alternative materials to suppress high leakage currents observed at low film thickness. In this work, thin layers of ZrO₂ and (ZrO₂)_x(Al₂O₃)_1−x, deposited on Si substrates are obtained by sol–gel method. The structural and electrical properties as a function of the annealing temperature are studied. Usually, the post-annealing temperature of 700 °C leads to re-crystallization in ZrO₂ layers, which can induce high leakage current and severe mass transport along the grain boundaries. The purpose is to amorphisize the films by adding aluminium oxide and in this way improve their electrical behaviour. Structural analysis shows that ZrO₂ films are crystallized, meanwhile the mixed oxide films remain in amorphous state even after high temperature annealing. The obtained results are encouraging and determine the (ZrO₂)_x(Al₂O₃)_1−x films as a promising material with good dielectric properties.