Carbon fiducial marks are formed during thin-film local delamination processes induced either by superlayer indentation forming circular blisters, or by residual stress relief through telephone cord blister formation. Hydrocarbons are sucked into the crack tip during the delamination process, outlining the crack- tip-opening angle, which can be used to back calculate thin-film adhesion using either elastic or plastic analyses presented here. Fiducial marks have been observed in two different thin-film systems, namely Cu/SiO2and TiWxNy/ GaAs. Cu/SiO2delamination blisters have been cross-sectioned using the focused-ion-beam method, and high-resolution scanning electron microscopy of the cross-sections revealed crack renucleation ahead of the original crack tip. This is attributed to the stress redistribution process due to the dislocation shielding mechanism. At stress intensity levels of 0.33 MPa m1/2it is found that four emitted dislocations can account for crack arrest, with renucleation of lOOnm sized nanocracks dependent on the antishielding stresses.
|Original language||English (US)|
|Number of pages||9|
|Journal||Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties|
|State||Published - Nov 2002|
Bibliographical noteFunding Information:
ACKNOWLEDGEMENTS The authors would like to acknowledge support through US Department of Energy grants DE-FG02/96ER45574 and DE-AC04-94AL85000. We would like to thank Lester Casoose for focused-ion-beam and SEM work. We would also like to acknowledge W. Miles Clift and Bernice E. Mills from Sandia National Laboratories at Livermore for Auger analysis on Cu films, and Robert F. Cook from the University of Minnesota and Joseph B. Vella for valuable discussions.