紫外光解法在制备低介电常数氧化硅分子筛薄膜中的应用

以正硅酸乙酯为硅源, 四丙基氢氧化铵(TPAOH)为模板剂和碱源, 采取水热晶化技术, 通过原位法在硅晶片表面制备出纯二氧化硅透明分子筛薄膜; 采用紫外光解法代替传统高温焙烧法脱除分子筛薄膜孔道内的模板剂, 制备出具有低介电常数的氧化硅分子筛薄膜. 使用FTIR、XRD和SEM对样品进行了结构表征, 并采用阻抗分析仪测量了薄膜的介电常数, 纳米硬度计测量薄膜的杨氏模量和硬度. 与传统的高温焙烧方法相比, 紫外光解法处理条件温和, 同时省时、省能、操作简易.

Application of Ultraviolet Treatment in the Synthesis of Pure-silica Zeolite Thin Films with Low Dielectric Constant

Transparent pure-silica zeolite (PSZ) films were synthesized on silicon wafers through hydrothermal reaction, in which tetraethyl orthosilicate (TEOS) was used as silica source, tetrapropyl ammonium hydroxide (TPAOH) as template and alkaline source. An ultraviolet treatment was subsequently applied to remove the organic templates within the pores/channels of zeolite films. The thin films were characterized by using FTIR, XRD, and SEM techniques before and after the ultraviolet treatment. FTIR results showed that the organic templates were effectively removed via ultraviolet treatment, which was the same as the results from the calcinations treatment. In comparison with the calcined films, XRD and SEMresults indicated that the crystallinity and the surface as well as the thickness of the films had no significant changes after ultraviolet treatment. Dielectric constant (ε) values of the thin films were measured by means of impedance analyzer. Elastic modulus and hardness of the thin films were measured by the nano-indentation technique. All results showed that the films after ultraviolet treatment had a lower ε value and higher mechanical strength. Therefore, it could be concluded that ultraviolet treatment was a faster, more energy-conservative method to remove template fromzeolite films, in comparison with conventional calcination.