Residual stress evolution of polymethylsilsesquioxane thin films with organic templates

Polymethylsilsesquioxanes (PMSSQs) and star-shaped 4 arm poly(ε-caprolactone)s (PCLs) were homogeneously mixed and chemically linked in their composites. Nanoporous PMSSQ films were made by curing and calcination of the composite films at the elevated temperature. The residual stresses of nanoporous PMSSQ films were analyzed to investigate the reliability of films in the multilayer devices. The residual stresses of PMSSQ/PCL composite films were highly dependent on factors such as the amount of the initial PCL loading and thermal process. The final stresses of nanoporous PMSSQ films ranged from 20 to 50 MPa at room temperature, depending on the initial PCL loadings. On heating run, the residual stress of the composite film was attributed to the competition between the relaxation and the curing of matrix polymers. On cooling run, the residual stress of nanoporous PMSSQ film was mainly due to the increased cure density, and the dimension shrinkage of networked matrix polymers.