Preparation and properties of nano-silica modified negative acrylate photoresist

A series of silica modified photoresists had been successfully developed through incorporation of a particular nanoparticles suspension. Free radical polymerization was employed to synthesize the binder, an acrylate copolymer resin of benzyl methacrylate, methacrylic acid and 2-hydroxycthyl methacrylate, of the photoresist. The acid value, viscosity, molecular weight and thermal properties of the formed binders were measured. Then, surface-modified silica particles prepared by the sol-gel method were introduced to the photoresist. Because the modified silica particles contained considerable amount of reactive double bonds (C=C) on their surfaces, they would react with the polyfunctional monomers in the photoresist to form an organic-inorganic nanohybrid. Fourier transform infrared spectrometer was used to analyze the evolution of chemical bonds at various stages of the preparation process. Thermal analyses including thermal gravimetric analyzer, differential scanning calorimeter and thermo-mechanical analyzer were used to evaluate the level of enhancement on thermal and dimensional stabilities of the photoresist due to silica incorporation. (C) 2008 Elsevier B.V. All rights reserved.