Hydrogen Effects on the Properties of Silicon/Nitrogen-Coincorporated Diamond-Like Carbon Films Prepared by Plasma-Enhanced Chemical Vapor Deposition

Tribological properties and thermal stability of hydrogenated, silicon/nitrogen-coincorporated diamond-like carbon films prepared by plasma-enhanced chemical vapor deposition

“…35) An HMDS molecule or a DMS molecule dissociates more easily than a CH 4 molecule, resulting in the increase in the number of radicals with HMDS or DMS flow ratio. [26][27][28] On the other hand, the deposition rates of the hydrogenated Si-N-DLC 28) films deposited using HMDS are higher than those of the hydrogenated Si-DLC films deposited using DMS. This is chiefly due to the difference in the number of atoms in a molecule between HMDS and DMS.…”

“…All the films show N=Si ratios close to that in an HMDS molecule (0.5). [26][27][28] Figures 3(a) and 3(b) show the visible Raman spectra of the films deposited at different HMDS and DMS flow ratios at a substrate bias voltage of −1000 V, respectively. The experimental Raman spectra can be fitted by two Gaussian components with large FWHMs at ∼1540 and ∼1350 cm −1 , which correspond to G (graphite) and D (disorder) peaks, respectively.…”

“…37,38) The downshift of the G peak with the Si fraction is a typical characteristic of Si-DLC films. 10,[26][27][28]39) The downshift of the G peak can be explained in terms of the physical changes in sp 2 C-C bonding. Since the electron affinity of C (2.5) is higher than that of Si (1.8), a C atom attracts more electrons from a Si atom bonding to the C atom.…”

“…25) We have prepared Si-N-DLC films by radio-frequency (RF) plasmaenhanced chemical vapor deposition (PECVD) using hexamethyldisilazane [((CH 3 ) 3 Si) 2 NH; HMDS] as the Si and N source. [26][27][28] We have obtained some important results: (1) the adhesion strengths of the hydrogenated Si-N-DLC films are higher than those of the hydrogenated Si-DLC films because of the further reduction of internal stress; (2) the friction coefficients of the Si-N-DLC films are as low as those of the Si-DLC films in air atmosphere; (3) in spite of almost the same Si fraction, the Si-N-DLC films have a higher wear resistance than the Si-DLC films; (4) the mechanical and tribological properties of the Si-N-DLC films prepared using a pulse substrate bias are further improved compared with those of the Si-N-DLC films prepared using a DC bias. 26,28) In our previous studies, hydrogenated Si-N-DLC films were deposited at a substrate bias voltage of −500 V. [26][27][28] As substrate bias voltage has significant effects on the mechanical and tribological properties of DLC films, it is necessary to examine its effects on the properties of hydrogenated Si-N-DLC films.…”

Structural and electrical properties and current–voltage characteristics of nitrogen-doped diamond-like carbon films on Si substrates by plasma-enhanced chemical vapor deposition

“…6, could also relieve the strain of carbon networks. 33,34) The formation of sp 1 C¸N bonds in the carbon network likely decreases the internal stress in the same way as hydrogen termination. Figure 8 shows the electrical resistivity of the films plotted as a function of N 2 flow ratio.…”