Methods of densifying films, cross-linking films, and controlling the stress of films are provided herein. Methods include forming a removable film on a substrate comprising a material to be densified, and annealing the substrate to transfer stress from the removable film to the material and thereby densify the material. Some methods involve depositing a tensile capping layer on the material to be densified on a substrate and annealing the substrate at a temperature greater than about 450° C. Some methods include clamping the substrate including the material to be densified to a shaped pedestal using an electrostatic chuck to apply compressive stress to the material to be densified.