溶胶-凝胶法制备纳米多孔SiO2薄膜

以正硅酸乙酯(TEOS)为原料，采用旋转涂敷的方法，结合溶胶-凝胶技术在硅衬底上制备超低介电常数多孔SiO₂薄膜.采用两种不同的改性方法对薄膜表面进行改性，傅里 叶变换红外光谱分析发现改性后薄膜中含有大量的—CH₃键，从而减少了孔洞塌陷.用扫 描电子显微镜观察薄膜的表面形貌，发现薄膜内孔洞尺寸在70—80 nm之间.调节溶胶pH值，发现pH值越小凝胶时间越长.对改性样品热处理的结果表明，在300 ℃时介电常数最低达2.05. 关键词： 2')" href="#">多孔SiO₂ 低介电常数 溶胶-凝胶

Deposition of nanoporous silica thin films by sol-gel

Low dielectric constant thin film of nanoporous silica synthesized by sol-gel was deposited on Si(100) substrate by spin coating. By detecting —CH₃ substituted for —OH species, which can avoid the destruction of network, surface modification was identified by Fourier transform infrared spectroscope. The hole size was about 70-80 nm observed from scanning electron microscope. By adjusting the pH value of the sol, we found that the gel time increased with the decrease o f the pH value of the sol. When heating the modified film at different temperatu res (60-400 ℃)， we can obtain the lowest dielectric constant 2.05 at 300 ℃ .