The decomposition of Ti͑N͑CH 3 ͒ 2 ͒ 4 ͑TDMAT͒ has been studied in N 2 and H 2 environments and surface temperatures between 473 and 623 K by using Fourier transform infrared spectroscopy. The pressure in the system was 5 Torr, with a TDMAT partial pressure of 0.3 Torr. The evolution of gas-phase species was monitored by characteristic infrared absorption. For temperatures less than 478 K, an average number of more than three ligands per TDMAT molecule is observed. Approximately one ligand per two TDMAT molecules decomposes into methane-and carbon-containing species in the coating. This slow decomposition pathway implies intermolecular hydrogen transfer between multiple TDMAT molecules. A decomposition mechanism consistent with the experimental observations is proposed. For temperatures greater than 478 K, the conversion rate of TDMAT into products increases drastically. Less gaseous species are observed, Auger electron spectroscopy measurements show more carbon contamination in the coating, and additional absorption peaks appear in the IR spectra. Nuclear magnetic resonance spectroscopy indicates that these peaks can be assigned to a mixture of oligomers of TDMAT reaction fragments that desorb from the hot surface. The increased carbon content at elevated temperatures is attributed to incomplete desorption of ligands or metallacycle formation.There has been extensive interest in chemical vapor deposition ͑CVD͒ of TiN coatings because of their useful materials properties and wide range of applications. The dense structure and the low resistivity of TiN make it a suitable diffusion barrier layer in semiconductor devices. 1-5 The high hardness of TiN makes it useful for wear resistant applications. 6,7 These characteristics, combined with its corrosion resistance, also make it a good biocompatible coating for implantable human body parts. 7 Thin coatings of TiN also find use as transparent conducting layers in liquid crystal displays. 8 Finally, the gold color of TiN is desirable for many decorative applications.TiN has traditionally been deposited using TiCl 4 and N 2 or NH 3 as precursors, 1,9 but growth temperatures are typically too high, and below ϳ900 K chlorine incorporation degrades the useful properties of TiN films. Metallorganic precursors, specifically tetrakisamidotitanium compounds ͓Ti͑NR 2 ͒ 4 ͑R ϭ CH 3 or C 2 H 5 ͔, have been explored as alternative precursors for deposition at lower temperatures. Thermal decomposition of tetrakis͑dimethylamido͒titanium ͑TDMAT͒ for the deposition of TiN for diffusion barriers resulted in very uniform films at temperatures between 653 and 743 K, but the coatings contained as much as 30 atom % carbon, which increased the electrical resistivity. 2 For wear resistant applications, incorporation of hydrocarbon fragments of TDMAT in the coating causes an unwelcome softening. The high carbon content in the deposit has been attributed to the formation of stable gas-phase intermediates. 10-13 The formation of metallacycles followed by the cleavage of the highly reactive meth...

A review is presented describing the development of TiN-CVD from the classical, high temperature T i C l m 2 process, towards low temperature MOCVD processes. This development is presented from a chemical point of view. In addition to low pressure (LPCVD) and atmospheric pressure (APCVD) thermal processing, also plasma enhanced (PECVD) techniques are described. In the past few years production facilities for good quality TiN layers for wear resistant applications have come on the market. Production facilities for IC-technology applications of CVD-TiN are on the edge of breaking through. For both applications deposition temperatures have been reduced to 500-600% Research developments, have shown even lower deposition temperatures possible for TiN and Ti(C,N) layers. # Metal organic compounds are defined as chemicals containing metal nitrogen or metal oxygen bonds (e.g. Ti(NMep)4), where organometallic compounds have metal carbon bonds (e.g. CpTiC7H7)

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Metal±organic and organometallic compounds are widely used as precursors for CVD processes. Most often these precursors are either liquid or solid at room temperature, and have to be evaporated at elevated temperatures. For accurate control of the feed rate of precursor to the Communications