Nanoindentation/Nanoscratching and Stress Studies in Monolithic and Nanolayered Amorphous Carbon Films
Abstract
We have recently reported that monolithic amorphous carbon (a-C) films deposited by RF magnetron sputtering exhibit a high level of sp(sup 3) sites when a negative bias voltage (V(sub b)) is applied onto the substrate. This type of a-C films are dense (^ 2.65 g/cu cm), hard (> 20 GPa) and highly stressed (6-7 GPa). The latter, however, limits their thickness below to ^ 40 nm. Thus, we have developed nanolayer structured a-C thick films with alternating V(sub b) (positive/negative) which are stable, hard and rich in sp(sup 3) content. Nanoindentation and low load scratch test results demonstrate that the layers rich in sp(sup 2) content promote the stress relaxation of the films during a compositional rearrangement when a layer rich in sp(sup 3) content is deposited. Possible explanations on the origin of the stress relaxation and the enhancement of the elastic properties in nanolayered a-C films are proposed and discussed based on the formation of compositional smooth interfaces between the two different types of layers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2000
- Accession Number
- ADP011824
Entities
People
- C. Charitidis
- M. Gioti
- S. Logothetidis
Organizations
- Aristotle University of Thessaloniki