Electrical and material stability of Orion™ CVD ultra low-k dielectric film for copper interconnection

The electrical and material stability of a newly developed CVD ultra low-k dielectric material called Orion, is explored. It has a dielectric constant of less than 2.2 with excellent thermal stability up to 600°C. It shows very low leakage current of only 1 nA/cm² at 2.5 MV/cm. Although both Al and Cu ions can be driven into Orion easily, no metal ions are observed in the Orion with a TaN gate. The Orion material also shows very good adhesion with TaN and oxide hardmask. The current transport mechanism and electrical reliability were investigated. Although weak dielectric polarization occurs under bias-temperature stress, Orion is a very promising material for next generation Cu-interconnect technology.