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Journal of Nanomaterials
Volume 2013 (2013), Article ID 486373, 9 pages
http://dx.doi.org/10.1155/2013/486373
Research Article

Wearout Reliability and Intermetallic Compound Diffusion Kinetics of Au and PdCu Wires Used in Nanoscale Device Packaging

1Spansion (Penang) Sendirian Berhad, Phase II Industrial Zone, Penang, 11900 Bayan Lepas, Malaysia
2Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000 Kangar, Perlis, Malaysia
3Spansion Incorporation, Sunnyvale, CA 94085, USA
4Spansion (Thailand) Limited, 229 Moo 4 Changwattana Road, Nonthaburi 11120, Thailand

Received 14 October 2012; Revised 15 December 2012; Accepted 16 December 2012

Academic Editor: Sheng-Rui Jian

Copyright © 2013 C. L. Gan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Wearout reliability and diffusion kinetics of Au and Pd-coated Cu (PdCu) ball bonds are useful technical information for Cu wire deployment in nanoscale semiconductor device packaging. This paper discusses the HAST (with bias) and UHAST (unbiased HAST) wearout reliability performance of Au and PdCu wires used in fine pitch BGA packages. In-depth failure analysis has been carried out to identify the failure mechanism under various wearout conditions. Intermetallic compound (IMC) diffusion constants and apparent activation energies ( ) of both wire types were investigated after high temperature storage life test (HTSL). Au bonds were identified to have faster IMC formation, compared to slower IMC growth of PdCu. PdCu wire was found to exhibit equivalent or better wearout reliability margin compared to conventional Au wire bonds. Failure mechanisms of Au, Cu ball bonds post-HAST and UHAST tests are been proposed, and both Au and PdCu IMC diffusion kinetics and their characteristics are discussed in this paper.