Electromigration reliability of low capacitance air-gap interconnect structures

Author

Shieh, B.P. ; Deal, M.D. ; Saraswat, K.C. ; Choudhury, Ruchika ; Park, C.-W. ; Sukharev, V. ; Loh, W. ; Wright, P.

Author_Institution

Center for Integrated Syst., Stanford Univ., CA, USA

fYear

2002

fDate

2002

Firstpage

203

Lastpage

205

Abstract

The electromigration lifetimes of aluminum lines with low capacitance air-gap structures is evaluated and compared to the case of traditional gapfill passivation. Electromigration lifetime of air-gap interconnect structures is determined to be significantly higher than that of the gapfill case. Failure analysis indicates that the elasticity of the airgap sidewall passivation reduces the line stress incurred during electromigration and increases the time necessary to reach the critical stress for void nucleation. Simulations support the experimental results. Capacitance measurements and simulations show the air-gap structures reduce capacitance by as much as 40%.

Keywords

air gaps; aluminium; capacitance; elasticity; electromigration; failure analysis; integrated circuit interconnections; integrated circuit metallisation; integrated circuit modelling; integrated circuit reliability; integrated circuit testing; nucleation; passivation; voids (solid); Al; air-gap sidewall passivation elasticity; air-gap structures; aluminum lines; capacitance measurements; electromigration lifetimes; electromigration reliability; failure analysis; gapfill passivation; line stress; low capacitance air-gap interconnect structures; simulations; void nucleation critical stress; Air gaps; Capacitance; Dielectrics; Electromigration; Large scale integration; Logic; Milling machines; Shape control; Testing; Thickness control;

fLanguage

English

Publisher

ieee

Conference_Titel

Interconnect Technology Conference, 2002. Proceedings of the IEEE 2002 International

Print_ISBN

0-7803-7216-6

Type

conf

DOI

10.1109/IITC.2002.1014934

Filename

1014934