实验条件对纳米多孔二氧化硅薄膜性能的影响  

Effects of Experimental Conditions on the Properties of Nanoporous Silica Films

作　　者：王娟[1] 张长瑞[1] 冯坚[1] 

机构地区：[1]国防科技大学航天与材料工程学院,湖南长沙410073

出　　处：《国防科技大学学报》2005年第3期16-19,29,共5页Journal of National University of Defense Technology

基　　金：国家部委重点资助项目(41312040307)

摘　　要：以正硅酸乙酯(TEOS)为先驱体,采用酸/碱两步溶胶—凝胶法,结合旋转涂胶和超临界干燥等工艺在硅片上制备了SiO2薄膜。XRD和AFM表明该SiO2薄膜为无定形态,具有多孔网络结构,表面均匀、平整,其SiO2粒子和孔隙的直径为30～40nm。利用椭偏仪测量了薄膜的厚度和折射率,薄膜的厚度为300～1100nm,折射率为1.13～1.23,孔隙率为50%～70%,介电常数为1.9～2.4。SiO2薄膜的厚度随溶剂异丙醇(IPA)用量的减少、催化剂NH4OH用量的增加、SiO2溶胶粘度的增大和旋转涂胶速度的降低而增大;介电常数随NH4OH用量和SiO2溶胶粘度的增加而降低,IPA用量和旋转速度对SiO2薄膜的介电常数影响较小。Crack-free homogeneous nanoporous silica films on silicon wafers has been synthesized via a supercritical drying of wet gel films that were obtained by spinning coating the polymeric silica sol using acid/base two step sol-gel method with tetraethoxysilane (TEOS) as precursor. The nanoporous film is amorphous and three-dimensioned network, cross-linked by the primary particles which sizes distributed between 30~40 nm showed by XRD and AFM. The thickness and refractive index of the silica films were measured by spectroscopic ellipsometry. The silica films' thickness is 300~1100 nm, refractive index is 1.13~1.23, porosity is 50%~70% and dielectric constant is 1.9~2.4. The silica films' thickness increases as the solvent isopropanol (IPA) amount reduced, catalyst NH4-OH amount increased, SiO2 sol viscosity increased and spin speed reduced. The films' dielectric constant lowers as NH4-OH amount and SiO2 sol viscosity increases while IPA amount and spinning speed has little effect on the films' dielectric constant.

关 键 词：纳米多孔SiO2薄膜 溶胶-凝胶 低介电常数 

分 类 号：TB321[一般工业技术—材料科学与工程]