Ionic Vibration Spectrum of Nanocrystalline MEL Pure Silica Zeolite Film

Abstract

Skeletal siloxane bonding structure of nanocrystalline MEL pure silica zeolite film was investigated. Nanocrystalline zeolite (nc-zeolite) suspension was prepared by the two-stage hydrothermal treatment, and thin film was obtained by spin-coating. After a quantitative analysis of Fourier-transform infrared spectra with the variable incidence angles of light probe, skeletal complex dielectric function concerning the siloxane bond vibration was derived in the 1400–400 cm–1 range. Then, the widening of the AS1-(LO-TO) frequency splitting width and the enhancement of the normalized integrated oscillator strength of AS vibration mode were observed in the nc-zeolite film in comparison with those of sol–gel derived amorphous silica film. Those improvements must be attributed to the increased siloxane network connectivity and the crystal structure of zeolite. The effect of the UV assist anneal was also discussed.

Relationships between the solution and solid-state properties of solution-cast low-k silica thin films

“…Thus, porous silica films composed of silica and air (vacancies in the films are filled with air) make ideal low-k materials. Solution-processed crystalline microporous silica (i.e., zeolite) films have been widely studied as low-k thin films, and a number of zeolite frameworks, including MFI, [46][47][48] MEL, [49][50][51][52][53] LTA, [54][55][56] and BEA, 57,58 have been explored. Despite the uniform periodic micropores of zeolite thinfilms, high crystallinity often leads to undesirable cracks in thin films resulting in low mechanical strength and high leakage current.…”

Effect of TMCTS silylation treatments on crosslinking density of low-k zeolite porous silica film

“…16) A MEL-type (Zeolite of Socony Mobile-Eleven) pure silica zeolite (PSZ) with pores of sub-1 nm has been proposed for low-k films. 17,18) The MEL-type PSZ has zeolite microcrystals inside the film, and a highly crosslinked silica skeleton is formed, so that the microcrystals strengthen its hardness. 19) MEL-type has high hydrophobicity at among others.…”

Low-k Mesoporous Pure Silica Zeolite Synthesis with Centrifugation Process of Zeolite Precursor

“…Pure silica zeolite with pores of sub-1 nm has been suggested for low-k [1]. The pure silica zeolite has zeolite microcrystals inside the film, and this microcrystal strengthen its hardness [2][3].…”