A novel fabrication of meso-porous silica film by sol-gol of TEOS

摘要

A homogeneous crack-free nano- or meso-porous silica films on silicon was fabricated by colloidal silica sol derived by hydrolyring tetraethyl orthosilicate (TEOS) catalyzing with (C_4H_9)_4N~+OH~- in water medium. The solution with ratio of H_2O/TEOS≥15, R_4N~+ and glycerol as templates, combining with the hydrolyzed intermediate, controlled the silica aggregating; the templated silica film with heterostructure was developed into homogeneous nano-porous then meso-porous silica films after being annealed from 750℃ to 850℃; the formation mechanism of the porous silica films was discussed; morphologies of the silica films were characterized. The refractive indexes of the porous silica films were 1.256-1.458, the thermal conductivity < 0.7 W/m/K. The fabricating procedure and the sequence had not been reported before.