AVS 50th International Symposium
    Thin Films Friday Sessions
       Session TF-FrM

Paper TF-FrM1
Island Coalescence Stress Created During Thin Film Growth

Friday, November 7, 2003, 8:20 am, Room 329

Session: Mechanical Properties of Thin Films
Presenter: S.J. Hearne, Sandia National Laboratories
Authors: S.J. Hearne, Sandia National Laboratories
J.A. Floro, Sandia National Laboratories
C. Dyck, Sandia National Laboratories
T. Christenson, Sandia National Laboratories
W. Fan, University of New Mexico
S.R.J. Brueck, University of New Mexico
Correspondent: Click to Email
For over 30 years it has been generally accepted that island coalescence during thin film growth results in a tensile stress. However, prior to this work there had been no conclusive demonstration of the fundamental physical mechanism underlying this process. Using selective lateral film growth on patterned substrates during electrodeposition of Ni films, we have obtained the first unambiguous comparison of the experimentally-measured tensile stress due to island coalescence with theoretical predictions. This technique allows for the systematic variation of island size and geometry while maintaining temporally constrains of the coalescence of Ni islands during electroplating. This avoided the complications associated with stochastic island coalescence that have plagued previous measurements obtained over the last 30 years. We found that the functional dependence of the stress on island size and dimensionality is consistent with a Hertzian contact model recently proposed by Freund and Chason.@footnote 1@ However, the absolute magnitude of the measured stress is smaller by factors of 2-4x, and reasons for the discrepancy will be discussed. This work was partially supported by the DOE Office of Basic Energy Sciences. Sandia is a multiprogram laboratory of the United States Department of Energy operated by Sandia Corporation, a Lockheed Martin Company, under contract DE-AC04-94AL85000. @FootnoteText@ @footnote 1@L.B. Freund, E. Chason, JAP 89, 4866 (2001).