Thin-Film Multilayer Capacitors Using Pyrolytically Deposited Silicon Dioxide

Thin-film multilayer high-energy-density capacitors have been constructed using a pyrolytically deposited phosphosilicate glass as the dielectric material with aluminum as the electrode material. Other electrode materials such as gold, chromium, and silicon were studied to determine the best electrode for this application. A careful study was made of the behavior of the oxide with respect to the formation of microcracks and pin holes in order to eliminate those problems. It was found that the stresses in undoped SiO2were too great to permit its use in this application. Capacitors having an area of 1 cm²with up to 20 layers were constructed using a doped oxide with a P2O5concentration of from 7 to 10 percent.