S. Amelio et al., Measurements of elastic properties of ultra-thin diamond-like carbon coatings using atomic force acoustic microscopy, THIN SOL FI, 392(1), 2001, pp. 75-84
We present a comparative study of the elastic stiffness of ultra-thin (5, 2
0 and 100 nm thick) diamond-like carbon coatings with a sampling depth less
than or comparable to the thickness of the coating. The experiments were c
onducted using atomic force acoustic microscopy, which is a dynamic operati
on mode of the atomic force microscope that permits the measurement of elas
tic properties with high spatial resolution. The method is based on the eva
luation of the shift of the cantilever resonance frequencies caused by the
contact stiffness between the sensor tip and the sample surface. Two sets o
f measurements are reported: one in which the silicon sensor tips were empl
oyed; and another set in which diamond-coated tips were used. The silicon t
ips showed considerable wear during data acquisition. Using the diamond-coa
ted tips, however, the wear could be avoided and qualitative measurements o
f high stability could be performed, thereby permitting the comparison of c
oatings obtained by different deposition techniques. It is also shown how t
he obtained results can lead to future quantitative measurements on stiff c
oatings. (C) 2001 Elsevier Science B.V. All rights reserved.