The roles of hydrophobic group on the surface of ultra low dielectric constant porous silica film during thermal treatment
The roles of hydrophobic group on the surface of ultra low dielectric constant porous silica film during thermal treatment
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DOI：
10.1016/j.tsf.2007.03.028
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发表时间：
2007-06-25
期刊：
影响因子：
2.1
通讯作者：
Chen, Wu-Nan
中科院分区：
文献类型：
--
作者：
Luo, Jen-Tsung;Wu, Wen-Fa;Chen, Wu-Nan
采用表面修饰模板法制备了具有超低介电常数（低于2）和低漏电流密度（在1.8MV/cm的电场下为10（-8）A/cm（2）或更低）的多孔二氧化硅薄膜。利用表面改性剂六甲基二硅氮烷（HMDS）在多孔二氧化硅薄膜表面形成疏水基团，防止水分的吸收。它有效地保留了薄膜的低介电常数特性。高温（> 350 ℃）热处理破坏了表面疏水基团，生成亲水基团（Si-OH），取代表面Si（CH 3）（3）基团，导致吸湿。然而，Si-OH不仅导致吸湿，而且还引发HMDS在表面上形成三甲基硅基。当损坏的膜再次被HMDS修复时，k值福尔斯下降到其初始值（其可以低于1.6）。形成了更致密的疏水性低k膜，并且改善了电性能。(C)2007 Elsevier B. V.保留所有权利。
Porous silica films with ultra low-k (below 2) and low leakage current densities (10(-8) A/cm(2) or lower at an electric field of 1.8 MV/cm) were prepared by the surfactant-template method. Hexamethyldisilazane (HMDS), a surface modification agent, was utilized to yield hydrophobic groups on the surface of porous silica film to prevent the absorption of moisture. It effectively retained the low permittivity properties of the films. Thermal treatment at high temperature (> 350 degrees C) destroyed surface hydrophobic groups and generated hydrophilic groups (Si-OH), which replaced the surface Si(CH3)(3) groups, and resulted in the absorption of moisture. However, Si-OH not only resulted in the absorption of moisture but also initiated the formation of trimethylsilyl groups on the surface by HMDS. When the damaged film is repaired by HMDS again, the k value falls to its initial value (which may be below 1.6). A denser hydrophobic low-k film is formed and the electrical properties are improved. (C) 2007 Elsevier B.V. All rights reserved.