Eur. Phys. J. B 48, 463-468 (2005)
https://doi.org/10.1140/epjb/e2006-00002-8

Structural characteristics of ultra-low k SiO₂ thin films prepared using a molecular template

¹ Department of Physics, Lanzhou University, Lanzhou 730000, P.R. China
² Physics Staff Room, the Sixth Middle School of Shijiazhuang, Shijiazhuang 050051, P.R. China

Corresponding author: ^a wangyy@lzu.edu.cn

Received: 15 January 2005
Revised: 25 September 2005
Published online: 19 January 2006

Abstract

Nanoporous SiO₂ thin films with ultra-low dielectric constants were synthesized using a molecular template method. Uniform films with pore size between 10 and 20 nm were obtained as observed by N₂ adsorption/desorption isotherms and transmission electron microscopy. Fourier transform infrared spectroscopy (FTIR) and differential thermal analysis were carried out to investigate the effect of n-hexane washing on structural properties before and after the surface modification process. The results showed that –OH bonds were substituted with –CH₃ bonds in the films as a result of modification of trimethylchlorosilane (TMCS)/n-hexane solution. Four kinds of model were used to analyze the relationship between porosity and dielectric constant of the films, where the dielectric constant was determined from capacitance-voltage measurements. The investigation indicated that the corresponding relationship was in accord with that estimated by the Rayleigh model.