PACVD of TIN

Transition-metal nitrides and carbides [1] of the fourth to sixth group of elements, well known as superrefractory materials, turn steadily increasing interest over the past two decades. Their complex bonding structure - a mixture of covalent, metallic and ionic components allows to the unique combination of properties (hard mechanical hardness, high electrical conductivity, chemical and thermal stability etc.) exclaiming to the various possibilities of otential applications. Usually used in thin film/coating form, these materials are successfully incorporated in the advanced technology as hard wear-resistant coatings on cutting tools [2], selectively-transmitting abrasion-resistant coatings on architectural glass [3], diffusion barriers in the integrated circuits [4] and active elements in superconducting devices [5]. Within the category of transition metal nitrides and carbides, titanium nitride (TiN) covers the widet area of commercial application. Titanium nitride crystallizes in the rocksalt structure with TiIN ratio equals to 1/1. The present phase contains a large fraction of vacancies on either the metal or non-metal sublattice (most commonly on nitrogen sublattice). The nitrogen content can vary in the compounds from TiN$_{0.6}$ to TiN$_{1.16}$ formation [1]. The material exhibits extremely high melting point (2960 °C). Its excellent high chemical and thermal stabilities in particular at elevated temperatures [6,7], the low bulk resistivity (15-20 $\mu \Omega \cdot$cm in dependence on the crystalline perfection) [8], highly pronouncedhardness and outstanding mechanical characteristics [9] provide to TiN importance in tool machining. TiN overlay coatings on different steel tools improve the surface mechanical properties, increase hardness and wear-resistance, lower frictional forces [10]. Due to the attractive golden-yellow lustre, TiN films are gaining the application in decorative purposes. Starting from the beginning of the last decade, the investigations on the application as a diffusion barrier in various semiconductor metallizationschemes [11] and as a contact layer for silicon or a gate electrode in metal/oxide semiconductor integrated circuits [12] have been performed. A particular interest appeared in the possibility of TiN applications as a solarenergy absorber [13]. The key to these success is the ability to deposit films with high intrinsic strength and a good adhesion to the basic material. Stoichiometric, as well as the off-stoichiometric, polycrystalline TiN coatings have been deposited on so far by the variety of techniques [14] including different $\underline{physical}$ $\underline{vapour}$ $\underline{deposition}$ (PVD) processes, i.e. reactive d.c. [15] and r.f. [15'] and magnetron [16] sputtering, ion- plating [17], activated reactive evaporation [I8], and $\underline{chemical}$ $\underline{vapour}$ $\underline{deposition}$ (CVD) [19]. [...