Friction measurements of CNx and TiCxNy films by scanning force microscopy

Nanotribological properties of CN/TiCN/TiN/Si multilayer as determined by AFM

“…µ CN = 0.17, µ TiCN = 0.25, µ TiN = 0.34) are in reasonable agreement with the macroscopic values reported for single layers of each compound. In particular, the low friction coefficient observed for the CN layer is in concordance with values measured previously in a similar material in the form of a single layer [23,24]. On the other hand, the values of the friction coefficient reported in the bibliography for TiC x N y layers are very dependent on the composition ratio of C/N [26,39] and the comparison has to consider this ratio.…”

“…The deposition parameters of the TiN layer were adjusted just to ensure good adhesion between the TiCN layer and the Si substrate. On the other hand, the deposition parameters of the CN and TiCN layers were selected in accordance with previous experience [23][24][25][26][27][28] to achieve a good hardness and wear resistance. The tribological properties (hardness, wear resistance and friction) were measured after deposition of each layer.…”

“…On the other hand, friction experiments were performed with a home-built AFM system [29] using the optical lever deflection method to simultaneously measure cantilever bending (normal force) and twisting (friction force). The microscope was operated under ambient conditions using NTMDT silicon rectangular cantilevers (nominal spring constants k c = 14 and 0.25 N m −1 ) and by means of a modified imaging technique specially designed to measure the friction behaviour of the scanned surface [24,30].…”

“…Friction measurements were performed with the AFM using rectangular silicon nitride cantilevers with two spring force constants (k c = 0.25 and 14 N m −1 ) to obtain different load ranges (up to 150 nN and up to 10 µN, respectively). The microscope was working in a modified contact mode imaging technique, explained in previous works [24,30], which provides friction measurements by taking friction images of the surface while the normal force is varied during the scanning. As the applied load is changed along the image, this method provides friction force versus normal load curves (i.e.…”