DRAM capacitor including Cu plug and Ta barrier and method of forming

摘要

A capacitor for a DRAM cell comprises a first electrode layer, a second electrode layer, and a dielectric film. The capacitor is disposed in a first opening defined in a second dielectric layer and overlaying a first plug through a first dielectric layer. The first plug is electrically connected to a transistor. The first electrode layer is electrically connected to the first plug. The second electrode layer can act as a barrier between a second plug exposed by a second opening and the second opening. The first and second electrode layer can be formed from Ta and TaN, and the dielectric film can be formed from tantalum oxide. A plug layer electrically connected to the second electrode layer can also be included. The plug layer can be formed from copper. A method of forming the DRAM capacitor is also disclosed.