Title :
Comparison of copper interconnect electromigration behaviors in various structures for advanced BEOL technology
Author :
Lin, M.H. ; Lin, Y.L. ; Yang, G.S. ; Yeh, M.-S. ; Chang, K.P. ; Su, K.C. ; Tahui Wang
Author_Institution :
United Microelectron. Corp., Hsin-Chu, Taiwan
Abstract :
Copper interconnect electromigration (EM) performance was examined in three low-k materials (k=2.65∼3.6) using advanced back end of line (BEOL) technology. Comparable time to failure distributions were achieved after process optimization for each material. The Ea and n ranged from 0.8 eV to 0.9 eV and 1.1 to 1.4, respectively, and agree well with the interface diffusion mechanism and void nucleation mechanism. Various testing structures were designed to identify the EM failure modes. Extensive failure analysis was carried out to understand the failure phenomena of various test structures. Results of the present study suggest that the interface of Cu interconnects is the key factor for EM lifetime performance for advanced BEOL technology design rules. The weak links of the interconnect system were also identified.
Keywords :
copper; diffusion; electromigration; failure analysis; integrated circuit interconnections; integrated circuit metallisation; integrated circuit reliability; nucleation; voids (solid); 0.8 to 0.9 eV; BEOL technology; Cu; EM failure modes; back end of line technology; dual damascene copper interconnects; failure analysis; interconnect electromigration; interconnect interface; interface diffusion mechanism; low-k materials; time to failure distribution; void nucleation mechanism; Copper; Dielectrics; Electromigration; Electrons; Failure analysis; Integrated circuit interconnections; NIST; Packaging; Testing; Thermal stresses;
Conference_Titel :
Physical and Failure Analysis of Integrated Circuits, 2004. IPFA 2004. Proceedings of the 11th International Symposium on the
Print_ISBN :
0-7803-8454-7
DOI :
10.1109/IPFA.2004.1345583
