Comprehensive investigations of CoWP metal-cap impacts on low-k TDDB for 32nm technology application

Author

Chen, F. ; Shinosky, M. ; Li, B. ; Christiansen, C. ; Lee, T. ; Aitken, J. ; Badami, D. ; Huang, E. ; Bonilla, G. ; Ko, T. -M ; Kane, T. ; Wang, Y. ; Zaitz, M. ; Nicholson, L. ; Angyal, M. ; Truong, C. ; Chen, X. ; Yang, G. ; Law, S.B. ; Tang, T.J. ; Peti

Author_Institution

Microelectron. Div., IBM, Essex Junction, VT, USA

fYear

2010

fDate

2-6 May 2010

Firstpage

566

Lastpage

573

Abstract

As the current-carrying capability of a copper line is reduced due to interconnect dimension shrinkage, self-aligned CoWP metal-cap has been reported to be helpful to improve degraded electromigration (EM) reliability. However, adoption of the metal cap in general further exacerbates the already problematic low-k dielectric TDDB reliability at 32nm and beyond. This paper provides a comprehensive study of CoWP metal-cap impacts on low-k TDDB for 32nm technology application. It was found that CoWP could induce a severe degradation of low-k TDDB if its process is not optimized, and its impacts on dense low-k and porous ultra low-k (ULK) dielectrics were different. An optimized CoWP process with the least defect density could lead to an acceptable TDDB performance as compared to the control for both dense low-k and porous ULK dielectrics, while showing substantial improvements in EM and stress migration (SM).

Keywords

copper; electric breakdown; electromigration; integrated circuit interconnections; integrated circuit reliability; low-k dielectric thin films; Cu; EM reliability; copper line current-carrying capability; defect density; electromigration reliability; interconnect dimension shrinkage; low-k dielectric TDDB reliability; porous ULK dielectric; self-aligned CoWP metal-cap; size 32 nm; stress migration; time dependent dielectric breakdown; Copper; Degradation; Dielectric materials; Electromigration; Inorganic materials; Integrated circuit interconnections; Materials reliability; Microelectronics; Samarium; Stress control; CoWP metal-cap; EM; SM; TDDB; leakage; low-k defect density; low-k reliability; time-dependent dielectric breakdown;

fLanguage

English

Publisher

ieee

Conference_Titel

Reliability Physics Symposium (IRPS), 2010 IEEE International

Conference_Location

Anaheim, CA

ISSN

1541-7026

Print_ISBN

978-1-4244-5430-3

Type

conf

DOI

10.1109/IRPS.2010.5488768

Filename

5488768