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A quantitative model for interpreting nanometer scale hardness measurements of thin films

Conference ·
OSTI ID:10186097
;  [1];  [2]
  1. Arizona Univ., Tucson, AZ (United States). Dept. of Materials Science and Engineering
  2. Oak Ridge National Lab., TN (United States)
A model was developed to determine hardness of thin films from hardness versus depth curves, given film thickness and substrate hardness. The model is developed by dividing the measured hardness into film and substrate contributions based on the projected areas of both the film and substrate under the indenter. The model incorporates constraints on the deformation of the film by the surrounding material in the film, the substrate, and friction at the indenter/film and film/substrate interfaces. These constraints increase the pressure that the film can withstand and account for the increase in measured hardness as the indenter approaches the substrate. The model is evaluated by fitting the predicted hardness versus depth curves obtained from titanium and Ta{sub 2}O{sub 5} films of varying thicknesses on sapphire substrates. The model is also able to describe experimental data for Ta{sub 2}O{sub 5} films on sapphire with a carbon layer between the film and the substrate by a reduction in the interfacial strength from that obtained for a film without an interfacial carbon layer.
Research Organization:
Oak Ridge National Lab., TN (United States); Oak Ridge Associated Universities, Inc., TN (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC05-84OR21400; AC05-76OR00033
OSTI ID:
10186097
Report Number(s):
CONF-930405--40; ON: DE93040601
Country of Publication:
United States
Language:
English