Cetyltrimethyl ammonium bromide (CTAB) templated mesoporous silica thin films were deposited on silicon substrate by evaporation-induced self-assembly (EISA) process using a spin coating method. The identification of mesophase with P6(3)/mmc space group was confirmed by using an X-ray diffraction (XRD) technique in Bragg-Brentano geometry along with the reported phase diagram. The determination of optimized spinning time was discussed and it was found that the mesophase formation in dynamic conditions during EISA is more important for the final mesophase formation rather than the modulable steady state. Tetraethoxysilane (TEOS) vapor treatment was conducted to improve the framework stability during calcination and reduce silanol in the framework. XRD patterns and Fourier transformed infrared spectra confirmed that the TEOS vapor treated samples have a strengthened framework and increased hydrophobicity showing the improved leakage current behavior, which suggests its potential application to intermetal dielectric. (C) 2004 Elsevier B.V. All rights reserved.