Amorphous carbon film growth on Si: Correlation between stress and generation of defects into the substrate

• Published in: Applied physics letters 2005-05, Vol.86 (22)
• Main Authors: Brusa, R. S., Macchi, C., Mariazzi, S., Karwasz, G. P., Laidani, N., Bartali, R., Anderle, M.
• Format: Article
• Language: English
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1940738

Amorphous carbon films of several thicknesses were prepared by graphite sputtering on crystalline silicon substrate. The samples were depth profiled with positron annihilation spectroscopy for open-volume measurements and characterized for their residual internal stress. It was found that after film growth the substrate presents vacancy-like defects decorated by oxygen in a layer extending in the substrate by several tens of nanometers beyond the film/Si interface. The width of the defected layer and the decoration of vacancy-like defects are directly and inversely proportional to the measured intensity of the residual stress, respectively. These findings indicate the existence of a relaxation mechanism of the stress in the films that involves deeply the substrate. The decorated vacancy-like defects are suggested to be bounded to dislocations induced in the substrate by the stress relaxation.