Low dielectric constant silica films prepared by a templating method

摘要

The preparation of low dielectric constant porous silica films by a templating method was studied in this research. Several organic compounds (including ionic and nonionic surfactants), which can be dissolved in the coating solution, were used as the template. They were applied to make pores in the film by burning them off during calcination in the air. TEOS (tetraethyl orthosilicate) was used as the silica source for the preparation of sol-gel. The processes that influenced the film thickness and the film surface modification were investigated. It was found from this research that the concentration of TEOS in the coating solution affected the film thickness the most. The spin speed during spin coating and the temperature increasing rate during the calcination process only slightly influenced the thickness. The surface modification was most successful when the film was immersed in the HMDS (1,1,1,3,3,3-hexamethyl disilazane) and toluene solution at 80degreesC. Moreover, for the templates tested in this research, it was found that the film using Tween 80 (polyoxyethylene(20) sorbitan monooleatel, a non-ionic surfactant) exhibited the lowest dielectric constant. [References: 11]