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

fYear

2003

fDate

2-4 June 2003

Firstpage

216

Lastpage

218

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;

fLanguage

English

Publisher

ieee

Conference_Titel

Interconnect Technology Conference, 2003. Proceedings of the IEEE 2003 International

Print_ISBN

0-7803-7797-4

Type

conf

DOI

10.1109/IITC.2003.1219758

Filename

1219758