Influence of air gaps on the thermal-electrical-mechanical behavior of a copper metallization

authored by

Irina Bauer, Kirsten Weide-Zaage, Lutz Meinshausen

Abstract

Shrinking the IC dimensions the dielectric insulation between metal interconnects has become one of the major limits on increasing circuit speed. A lot of possible new low-k materials failed to meet specifications: too leaky, too soft, too unstable, and too expensive. Due to this air gaps beside the metallization are one solution. The reliability of ULSI multilevel copper metallizations under electro- and stress migration stress test conditions is investigated here with finite element analysis. A determination of the electrical and mechanical stress in a 3D copper metallization model based on the 45 nm technology node is carried out and the impact of a variation of the applied current density as well as geometrical parameters on the thermal-electrical and mechanical behavior is investigated. For a determination of the reliability the mass flux and mass flux divergence are separately calculated by a user routine. The influence of air gaps on single via structures and structures with a chain of four vias on the thermal-electrical-mechanical behavior is determined.

Organisation(s)

Laboratorium f. Informationstechnologie

Type

Article

Journal

Microelectronics reliability

Volume

51

Pages

1587-1591

No. of pages

5

ISSN

0026-2714

Publication date

09.2011

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Atomic and Molecular Physics, and Optics, Safety, Risk, Reliability and Quality, Condensed Matter Physics, Surfaces, Coatings and Films, Electrical and Electronic Engineering

Electronic version(s)

https://doi.org/10.1016/j.microrel.2011.07.011 (Access: Unknown)