Title :
Suppression of bimodal stress-induced voiding using high-diffusive dopant from Cu-alloy seed layer
Author :
Tonegawa, T. ; Hiroi, M. ; Motoyama, K. ; Fujii, K. ; Miyamoto, H.
Author_Institution :
Adv. Technol. Dev. Div., NEC Electron. Corp., Kanagawa, Japan
Abstract :
The effect of impurity doping to Cu from Cu-alloy (CuSn and CuTi) seed layer on stress-induced voiding in Cu dual-damascene interconnects has been investigated. Significant suppression of both voiding inside vias and under vias was observed for CuSn. In addition, CuSn had 9 times the electromigration resistance of pure Cu, with available increments of sheet resistance. The difference in terms of reliability improvement between the doping materials is due to higher diffusivity of Sn into Cu in comparison to Ti. We have demonstrated high reliable Cu dual-damascene interconnects using high-diffusive dopant in the Cu-alloy seed layer.
Keywords :
chemical interdiffusion; copper alloys; doping profiles; electromigration; integrated circuit interconnections; reliability; tin alloys; titanium alloys; voids (solid); Cu dual-damascene interconnects; Cu-alloy seed layer; CuSn; CuTi; bimodal stress-induced voiding suppression; diffusivity; doping materials; electromigration resistance; high-diffusive dopant; impurity dopant effect; reliability; sheet resistance; Dielectrics; Doping; Electromigration; Mass spectroscopy; Materials reliability; Scanning electron microscopy; Testing; Thermal stresses; Tin; Transmission electron microscopy;
Conference_Titel :
Interconnect Technology Conference, 2003. Proceedings of the IEEE 2003 International
Print_ISBN :
0-7803-7797-4
DOI :
10.1109/IITC.2003.1219758
