Characterization of negative-type photoresists containing polyhedral oligomeric silsesquioxane methacrylate

A series of negative-type photoresists made by blending with various contents of polyhedral oligomeric silsesquioxane (POSS) methacrylate were prepared and characterized. These POSS macromers tend to crystallize or aggregate to form their own domains within the photoresist matrix. Sensitivity of the POSS modified photoresist is significantly improved with the increase of the POSS content. Results from photo-DSC analyses indicate that both induction time and peak maximum of heat flux are reduced by blending with POSS macromer. Addition of the proper amount (<13 wt%) of POSS can effectively increase photo-polymerization rate and exothermic heat. Hydrogen bonding interaction between the hydroxyl of photoresist and the siloxane of POSS tends to attract methacrylate double bonds surrounding POSS particles locally and thus enhances the rate of photo-polymerization and sensitivity.