Amorphous Carbon Film Growth on Si Correlation Between Stress and Generation of Defects into the Substrate

R.S. BRUSA; C. MACCHI; S. MARIAZZI; G.P. KARWASZ; N. LAIDANI; R. BARTALI; M. ANDERLE

APPLIED PHYSICS LETTERS

AMER INST PHYSICS

Lugar: New York; Año: 2005 vol. 86 p. 1 - 3

0003-6951

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.