Analysis of Al doping effects on resistivity and electromigration of copper interconnects

作者：Yokogawa Shinji^*; Tsuchiya Hideaki; Kakuhara Yumi; Kikuta Kuniko

来源：IEEE Transactions on Device and Materials Reliability, 2008, 8(1): 216-221.

DOI：10.1109/TDMR.2007.915003

• copper alloys
• electromigration (EM)
• reliability
• resistivity

In this paper, we investigated the effect of impurity (aluminum; Al) doping on the resistivity of damascene copper (Cu) interconnects by categorizing it into surface, grain-boundary, and impurity-scattering factors by means of a comprehensive scattering model. Segregation of Al dopant atoms to the interface of the lines increases the resistivity through increased surface scattering. Electromigration (EM)-induced Cu drift is suppressed as the Al concentration increases. The EM lifetime is improved by the suppression of Cu diffusion due to the piled-up Al at the top surface of the Cu interconnects.

• 出版日期2008-3