University of Illinois Urbana-Champaign

Effect of native AL2O3 on the elastic response of nanoscale aluminum films

Saif,M. Taher A.; Zhang, Sulin; Haque, Amanul; Hsia, K. Jimmy

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https://hdl.handle.net/2142/112687

Description

Title
Effect of native AL2O3 on the elastic response of nanoscale aluminum films
Author(s)
  • Saif,M. Taher A.
  • Zhang, Sulin
  • Haque, Amanul
  • Hsia, K. Jimmy
Issue Date
2002-01
Keyword(s)
  • Aluminum Films
  • Nanoscale Aluminum Films
  • Elastic Response
  • Mems Techniques
Abstract
A continuous, dense aluminum oxide (Al2O3) layer of about 5 nm forms on the surface of Al alloys upon exposure to oxygen or dry air, thus preventing further oxidation of the alloy. Since the elastic moduli of Al and Al2O3 are 69 GPa and 370 GPa, respectively, the elastic modulus of a thin Al film of sub-micron dimension (with the native oxide layer) should be much higher than that of pure Al. However, uniaxial tensile measurements on Al films with thickness down to 50 nm revealed an effective modulus close to 69 GPa. ln the present paper, we investigate a plausible mechanism for this discrepancy, namely, the effect of wavy surface oxide layer. Here thin Al films are considered as AI- Al2O3 composites. Uniaxial tensile experiments on a freestanding, 200 nm thick Al film are performed using MEMS techniques. The surface morphology of the specimen is characterized by AFM. An analytical model is developed to estimate the effective modulus, Ē , of a wavy oxide layer. The current study shows that the model predictions using measured material parameters agree reasonably well with the experimental results, thus supporting the validity of the proposed mechanism.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 995
  • 2002-6003
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112687
Copyright and License Information
Copyright 2002 Board of Trustees of the University of Illinois

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