Preparation of Silica Films by Sol-Gel Process

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J. Korean Ceram. Soc. > Volume 36(9); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(9): 893.

졸-겔 법을 이용한 실리카 박막의 제조

이재준, 김영웅, 조운조¹, 김인태, 제해준², 박재관

한국과학기술연구원 복합기능세라믹연구센터
¹광기술연구센터
²세라믹공정연구센터

Preparation of Silica Films by Sol-Gel Process

ABSTRACT

Silica films were prepared on Si single crystal substrates by sol-gel process using TEOS as starting materials. Films were fabricated by a spin coating technique. Sol solutions were prepared by varying the compositions of CH3OH, H2O and DMF with fixed molar ratio of TEOS=1, HCl=0.05(mol). Wetting behavior viscosity of solutions gelation time thickness of films and cracking behavior were investigated with the various solution compositions. Wetting behaviors of solutions depended on the solution compositions mixing method and mixing rate. The optimum composition of sol was TEOS : DMF ; CH3OH: H2O :HCl=1:2:4:4:0.05(mol) and the mixing rate of solution was optimized at 1 ml/min. Viscosity of solutions were controlled by choosing a reaction time(elapsed time after mixing) at a room temperature so that we could get up to 800nm thick film The surface roughness was getting poor when thickness of films was thicker than 500nm. Thickness of coated films were increased with decreasing amount of CH3OH. The best surface roughness was obtained at the content of CH3OH 4 mol. The shortest gelation time was obtained with the content of CH3OH 8 mol. Crack-free filkms were fabricated when sintered at 500$^{circ}C$ for 1 hr with heating rate of 0.6$^{circ}C$/min.

Key words: Silica Films, Sol-Gel Process, Wetting, Gelation time, Crack-free