Increase in EM resistance by planarizing dielectric film over Al wirings

Abstract

The relation between EM (electromigration) characteristics and interlayer dielectric film structure is described. It was found that a well-planarized interlayer significantly increases EM resistance for underlying Al wirings. This EM improvement is attributed to reinforcement and crack suppression at interlayer sidewalls. A constant atom flux model is proposed that explains the mechanism for this phenomenon.<>