High modulus, low dielectric constant coatings

This invention relates generally to coatings for use in electronic devices. More particularly, the invention relates to coatings having an improved elastic modulus and a low dielectric constant and to methods of making such coatings. Low dielectric constant films with improved elastic modulus. The method of making such coatings involves providing a porous network coating produced from a resin containing at least 2 Si-H groups where the coating has been thermally cured and has a dielectric constant in the range of from about 1.1 to about 3.5, and plasma treating the coating to convert the coating into porous silica. Plasma treatment of the network coating yields a coating with improved modulus, but with a higher dielectric constant. The coating is plasma treated for between about 15 and 120 seconds at a temperature less than or about 350° C. The plasma treated coating can optionally be annealed. Rapid thermal processing (RTP) of the plasma treated coating reduces the dielectric constant of the coating while maintaining an improved elastic modulus as compared to the initial porous coating. The annealing temperature is preferably in excess of or about 350° C., and the annealing time is preferably at least or about 120 seconds. The annealed, plasma treated coating has a dielectric constant in the range of from about 1.1 to about 2.4 and an improved elastic modulus.