Title :
Electromigration lifetime improvement of copper interconnect by cap/dielectric interface treatment and geometrical design
Author :
Lin, M.H. ; Lin, Y.L. ; Chen, J.M. ; Yeh, M.-S. ; Chang, K.P. ; Su, K.C. ; Wang, Tahui
Abstract :
A significant improvement of electromigration (EM) lifetime is achieved by modification of the preclean step before cap-layer deposition and by changing Cu cap/dielectric materials. A possible mechanism for EM lifetime enhancement was proposed. Cu-silicide formation prior to cap-layer deposition and adhesion of Cu/cap interface were found to be the critical factors in controlling Cu electromigration reliability. The adhesion of the Cu/cap interface can be directly correlated to electromigration median-time-to-failure and activation energy. Effects of layout geometrical variation and stress current direction were also investigated.
Keywords :
adhesion; copper; dielectric materials; electromigration; integrated circuit interconnections; integrated circuit reliability; Cu; Cu cap material; Cu electromigration reliability; Cu-silicide formation; EM lifetime enhancement; activation energy; cap-layer deposition; cap/dielectric interface treatment; copper electromigration; copper interconnect; dielectric material; electromigration lifetime; electromigration median-time-to-failure; geometrical design; preclean step; preclean treatment; stress current direction; Adhesives; Conducting materials; Copper; Dielectric materials; Electromigration; Integrated circuit interconnections; Microelectronics; Stress; Surface treatment; Testing; Copper electromigration (EM); Cu-silicide; Cu/cap interface; preclean treatment;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2005.859597
