Sol-gel fabrication of dielectric HfO2 nano-films;: Formation of uniform, void-free layers and their superior electrical properties
Sol-gel fabrication of dielectric HfO2 nano-films;: Formation of uniform, void-free layers and their superior electrical properties
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DOI：
10.1021/cm048971r
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发表时间：
2005-01-25
影响因子：
8.6
通讯作者：
Nakao, A
中科院分区：
文献类型：
--
作者：
Aoki, Y;Kunitake, T;Nakao, A
报道了采用表面溶胶-凝胶法和后处理技术制备高质量金属氧化物纳米薄膜(厚度约10 nm)。在甲苯-乙醇中化学吸附正丁氧基Hf(IV)，得到均匀的凝胶层，其中的醇盐基团被水解，并经历第二次化学吸附/水解。在500℃下对10个循环的薄膜进行热处理，可以得到厚度为5.7 nm的均匀的、无孔洞的HfO2层。其电学性能、介电常数、漏电流和介电击穿与传统气相沉积法制备的HfO2薄膜相当。另一方面，通过旋涂法制备的类似的HfO2纳米薄膜在高分辨率的透射电子显微镜图像中提供了不太均匀的层。后一种薄膜的电学性能远不如表面溶胶-凝胶膜。实验结果表明，溶液法制备金属氧化物介电纳米薄膜是一种可行的方法。
Solution-based fabrication of a high-quality metal oxide nano-film (similar to10-nm thickness) by the surface sol-gel process and postannealing is reported. Hafnium(IV) n-butoxide in toluene-ethanol was chemisorbed onto hydroxylated Si wafer to give a uniform gel layer, of which alkoxide group was then hydrolyzed and subjected to a second cycle of chemisorption/hydrolysis. Annealing of a 10-cycle film at 500 degreesC produced uniform, void-free HfO2 layer of 5.7-nm thickness. Its electrical properties, dielectric constant, leakage current, and dielectric breakdown were comparable to the HfO2 film as prepared by the conventional vapor deposition method. On the other hand, a similar HfO2 nano-film prepared by spin-coating provided a less homogeneous layer in a high-resolution TEM image. The electrical properties of the latter film were much inferior to those of the surface sol-gel film. We concluded that the solution-based method is suitable for fabrication of dielectric nanofilms of metal oxide.