Atomic layer deposition (ALD) of amorphous TiN films on SiO2 between 170°C and 210°C has been investigated by alternate supply of reactant sources, Ti[N(C2H5CH3)2]4 [tetrakis(ethylmethylamino)titanium:TEMAT] and NH3. Reactant sources were injected into the reactor in the following order:TEMAT vapor pulse, Ar gas pulse, NH3 gas pulse and Ar gas pulse. Film thickness per cycle was saturated at around 1.6 monolayers (ML) per cycle with sufficient pulse times of reactant sources at 200°C. The results suggest that film thickness per cycle could exceed 1 ML/cycle in ALD, and are explained by the rechemisorption mechanism of the reactant sources. An ideal linear relationship between number of cycles and film thickness is confirmed. As a result of surface limited reactions of ALD, step coverage was excellent. Particles caused by the gas phase reactions between TEMAT and NH3 were almost absent because TEMAT was segregated from NH3 by the Ar pulse. In spite of relatively low substrate temperature, carbon impurity was incorporated below 4 at.%.

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Wear resistant titanium carbonitride (TiCxNy) films were deposited onto high speed steel (AISI M2) by plasma assisted chemical vapor deposition using the gaseous mixture of TiCl4, CH4, N2, H2, and Ar. The effects of deposition conditions on the deposition rate and residual chlorine content were investigated. The influences of the chlorine on the crystallinity, microstructure, and mechanical properties of coatings were also studied. It was found that the residual chlorine content in the films greatly varied with the deposition conditions. Subsequently the crystallinity of the TiCxNy films deteriorated with the increase in the chlorine content. The microhardness and adhesion strength also decreased with the chlorine content. However, in spite of the low residual chlorine content, TiCxNy film deposited at high radio-frequency power shows inferior mechanical properties due to the micropore network structure.

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