Reliability challenges and recent advances for Cu interconnects

Summary form only given. This paper discusses the reliability issues for Cu/low k interconnects, focusing on the impact due to the thermomechanical properties of low k dielectrics. Several basic questions arise concerning the dielectric effects on interconnect reliability, including the rate of mass transport, thermal stress and deformation behavior and failure mechanisms. In this paper, we address these issues and highlight some recent advances in understanding and improvement of electromigration (EM) and packaging reliability. We first discuss how materials and processes of the damascene structure lead to distinct characteristics and mechanisms for EM and packaging reliability of Cu interconnects. Then the impact of the low k dielectrics on reliability are discussed by comparing results from Cu/oxide and Cu/low k interconnects. Finally, we discuss recent advances and approaches developed to address these reliability challenges.