Abstract
The adhesion of sputtered copper thin films was measured with a quantitative indentation technique utilizing refractory superlayers to trigger and promote delamination. Adhesion energies of the indentation-induced delaminations were analyzed in terms of the critical strain energy release rate. Two groups of films were investigated. Group I ranged in thickness from 225 to 1000 nm in both the as-deposited and annealed condition. Adhesion energies ranged from 2 to 15 J/m2, with higher adhesion for the annealed condition. Group II films had nominal thicknesses of 430 and 1100 nm, some with 7-10 nm interlayers of either titanium or chromium. Adhesion energies of these films ranged from 4 to 30 J/m2, increasing by a factor from 1.3 to 7.5, as a function of the interlayer presence and type, with the increase in energy due to a chromium interlayer exceeding that of titanium. Adhesion energies increased with film thickness for all films, with interlayers and annealing producing a larger increase. These quantitative results were compared to previous semi-quantitative and quantitative results, and shown to have comparable magnitudes and trends.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6623-6630 |
| Number of pages | 8 |
| Journal | Acta Materialia |
| Volume | 46 |
| Issue number | 18 |
| DOIs | |
| State | Published - Nov 1998 |
Bibliographical note
Funding Information:The authors would like to gratefully acknowledge support for this work by the Center for Interfacial Engineering at the University of Minnesota under grant NSF/CDR-8721551 for facilities usage, the Department of Energy under DOE/DE-FG02/96ER45574 for MDK and WWG, and the Department of Energy under DOE contract DE-AC04-94AL85000 for NRM. The assistance of Maarten deBoer was also greatly appreciated in the development of this work.