A method of stabilizing a poly(paraxylylene) dielectric thin film after forming the dielectric thin film via transport polymerization is disclosed, wherein the method includes annealing the dielectric thin film under at least one of a reductive atmosphere and a vacuum at a temperature above a reversible solid phase transition temperature of the dielectric film to convert the film from a lower temperature phase to a higher temperature phase, and cooling the dielectric thin film at a sufficient rate to a temperature below the solid phase transition temperature of the dielectric thin film to trap substantial portions of the film in the higher temperature phase.