The objective of this research is to investigate methods for the fabrication of high energy density capacitors using oxygen-doped aluminum nitride (O-AlN) films as dielectric medium and to test their performance at high temperature and high current modes. The electrical properties of amorphous (O-AlN) film make it a potential candidate for use in capacitors for pulse forming networks. Its desirable properties includes: (a) very high breakdown strength, (b) very high resistivity, (c) excellent thermal conductivity, (d) high chemical inertness to oxygen at high temperature, (e) very low dissipation factor, and (f) very high high decomposition temperature. Under this proposal it is intended to investigate: (1) optimum conditions for the growth of high quality amorphous O-AlN films on aluminum foil, glass and silicon wafer, and (2) the fabrication of prototype high energy density of O-AlN capacitors, and perform high voltage and high temperature testing. The compact, high temperature and high energy density of O-AlN capacitors with high reliability have a myriad of in both commercial and military applications. The high temperature capability of O-AlN capacitors will enable high temperature electrically-driven aircraft accessories to be realized such as engine-mounted actuators and remotely mounted flight control actuactors as envisioned for the far term More Electric Aircraft (MEA), Directed Energy Weapons (DEW), Directed Energy Attack Aircraft (DE ATAC), Unmanned Combat Aerial Vehicle (UCAV) and High Power Microwave (HPM) demonstration program. The military will also benefit from O-AlN capacitors in Electric Propulsion Power Conditioning, Space Based Laser (SBL), Space Plane Power Management and Distribution (PMAD). High energy density capacitors are greatly needed for DOD pulse power applications. Also, commercial applications are widespread. These include utilities, deep-well drilling gear, power supplies, commercial aircraft, communication satellites and automobiles, medical instruments, small and large appliances