High-performance tantalum oxide capacitors fabricated by a novel reoxidation scheme

High-performance tantalum oxide capacitors with excellent reliability that were developed by a two-step oxidation scheme are discussed. An anodic reoxidation process is applied to the reactively sputter-deposited tantalum oxide films to make the densified oxide structure. The electrical and physical properties as well as the reliability of these two-step oxidized sputtered/anodized tantalum oxide films are shown to be much superior to those of conventional tantalum oxide films prepared by either anodization or sputtering alone. Capacitors made of the sputtered/anodized tantalum oxide film have greatly improved electrical properties and better reliability than anodized or sputtered tantalum oxide capacitors and are very useful for applications to high-capacity storage capacitors in future high-density VLSI memories.>