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Single- and dual-cathode DC magnetron sputtering was used to produce Ti[B.sub.2] coatings and C[N.sub.x]/ZrN multilayers, respectively, with hardness exceeding 40 GPa. The composition, structure, topography, and mechanical properties were determined by various techniques, including Auger electron spectroscopy, X-ray diffraction, high-resolution electron microscopy, atomic force microscopy, and nanoindentation. An optimum combination of the sputtering pressure and substrate bias results in the production of ultrasmooth Ti[B.sub.2] coatings with hardness up to 50 GPa and excellent wetting properties. The rationale for studying the C[N.sub.x]/ZrN system is that ZrN (111) provides excellent lattice match to the hypothetical [Beta]-[C.sub.3][N.sub.4](0001) face ([Beta]-[C.sub.3][N.sub.4] was predicted to have mechanical properties comparable to diamond). Using a dual-cathode sputtering system, we produced crystalline multilayers of C[N.sub.x]/ZrN with bilayer thickness of 1-2 nm. Using various combinations of nitrogen partial pressure, target powers, and substrate bias, we found that the hardness of these coatings correlates very strongly with the occurrence of (111) texture of ZrN, consistent with the lattice-match strategy. Even with a ZrN volume fraction of 70 percent, such multilayer coatings have been synthesized with hardness in the 50 GPa regime.

The characteristics of carbon nitride thin films grown by dc magnetron sputtering of a graphite target on (001) oriented Si substrates were investigated using nano-indentation studies. The results showed that the films were amorphous and had small volumes of nanocrystallites. The hardness exhibited a dependence on the deposition process parameters.

The article reports combined effects of Ar addition and substrate bias on the grain size, microstructure, and growth rate of the diamond films prepared in microwave plasma-enhanced chemical vapor deposition. The nanocrystalline diamond (NCD) films with grain size of 50-100 nm, characterized by Raman spectra, scanning and transmission electron microscopy, were produced at 90-99 vol% Ar concentration under -50 V substrate biasing. The growth rate of the NCD films was 0.7-0.8 μm h[SUP-l], larger apparently than those grown by only Ar addition or by substrate bias effect alone. The NCD formation by various mechanisms is discussed, and a revised C[SUB2] insertion mechanism by the promotion of H[SUP+] ions is proposed to interpret the higher growth rate of the NCD films. [ABSTRACT FROM AUTHOR]

The influence of negative substrate bias on the crystallinity, morphology, and growth rate of the diamond films deposited using microwave plasma-enhanced chemical vapor deposition in 1% CH[sub 4]/H[sub 2] plasma were investigated. The nanocrystalline diamond films were produced exclusively under the biasing at -250 V. With -50 V biasing, faceted (111) microcrystalline diamond films at higher growth rate than no-bias samples were produced. When the biasing between - 100 and -200 V, faceted (100) diamond films with decreasing grain size were favored, and the growth rates were gradually reduced along with the increasing biasing. The results indicate that the etching efficiency of H[sup +] ions is enhanced with the increasing kinetic energy obtained from the increasing bias voltage. On the other hand, CH[sup +, sub x] ions at -250 V biasing would have sufficient energy to perform the ion subplantation model to grow the nanocrystalline diamond films by bias-enhanced nucleation. [ABSTRACT FROM AUTHOR]