Titanium nitride production

Many CVD reactions are being investigated for the deposition of carbides and nitrides, particularly for titanium nitride for semiconductor applications, such as diffusion barrier. The following is a summary of the metallo-organic precursors and deposition condition presently used in development or production of these materials. 

DLC coatings are already in production in several areas (optical and IR windows) and appear particularly well-suited for abrasion and wear applications due to their high hardness and low coefficient of friction. They have an extremely smooth surface and can be deposited with little restriction of geometry and size (as opposed to CVD diamond). These are important advantages and DLC coatings will compete actively with existing hard coatings, such as titanium carbide, titanium nitride, and other thin film... 

Researchers in Japan have determined that copper interconnects deposited by metallo-organic chemical vapor deposition (MOCVD), then followed by chemical mechanical polishing, provides sub-quarter-micron interconnects and can be achieved on a production basis. Titanium nitride and borophosphosilicate glass provide effective barriers against copper diffusion.PL[H]... 

The DPE reduction is used as a test reaction to characterize the materials and optimize the preparation conditions of the catalyst. Since hydroaluminations can also be used for the synthesis of carboxylic acids, deuterated products, or vinyl halides via quenching with CO2, D2O or Br2 [44], the method is also a valuable organic synthesis tool. However, as compared with molecular catalysts like Cp2TiCl2 that are known to catalyze hydroaluminations [44], the titanium nitride materials described here are solid catalysts and can be separated by centrifugation. Moreover, they can be reused several times, which is an advantage as compared to molecular catalysts. 

In 1849 Wohler and H. Sainte-Claire Deville attempted to prepare pure titanium by Berzelius method, but used a closed crucible in order to exclude air. When they found that the product thus obtained still contained titanium nitride, they heated boats containing potassium and potassium fluotitanate in an atmosphere of hydrogen and obtained a gray powder which showed a metallic luster when examined with a microscope (7,10,18). Wohler and Deville thought they had the metal, but, in the opinion of W. M. Thornton, Jr. (23), they were still dealing with the nitride. 

The most frequent impurities of commercial a-titanium trichloride are generally other chlorides (TiCU, TiCU), metallic titanium, titanium nitride, and the products resulting from oxydation or hydrolysis of the titanium chlorides, the latter being unstable at air and moisture. 

Nitrides such as TiN, AIN, ZrN, HfN, TaN, and Si3N4 and carbonitrides, such as TiCN, NbCN and ZrCN are among the important industrial products formed by the SHS process. Due to the high thermodynamic stability of titanium nitride and titanium carbide, their formation using the SHS method is highly favored even at relatively low pressures of nitrogen. 

The reaction product (golden-yellow titanium nitride) was confined to a... 

An unusual new synthesis method involves carrying out reactions in a molten salt medium, and has been used on an industrial scale for the production of metallic nitride, carbide or carbonitride powders.25 An illustration of this CEREX process is the preparation of oxygen-free titanium nitride in molten calcium chloride. The method involves the reaction between titanium tetrachloride and calcium nitride ... 

A variety of other ceramics are prepared by pyrolysis of preceramic polymers.32,38 Some examples are silicon carbide, SC, tungsten carbide, WC, aluminum nitride, AIN, and titanium nitride, TiN. In some cases, these materials are obtained by simple pyrolysis in an inert atmosphere or under vacuum. In other cases a reactive atmosphere such as ammonia is needed to introduce some of the atoms required in the final product. Additional details are given in Chapter 9. 

In order to be able to state that a conductive probe works, it should be stable over at least several hours. This is principally a question of the wear resistance of the conductive coating and additionally of its ability to withstand high current densities or the resulting temperature. Within the production process one has to ensure that the very last nanometers of the tip are conductive [440]. Conductive diamond and other commercially available hard coatings (tungsten carbide, W2C, and titanium nitride, TiN), as well as some other metals evaporated in our in-house production, are used in our studies. 

Ternary phases with structures different from those of the phases of the binary boundary systems are more the exception than the rule. Such phases have been reported in the systems Nb-Mo-N, Ta-Mo-N, Nb-Ta-N, Zr-V-N, Nb-Cr-N, and Ta-Cr-N. Information about ternary transition metal-nitrogen systems is often available for specific temperatmes only. This is even more the case for quaternary nitride systems, which play a role in the production of carbonitride cermets where quaternary compounds of the types (Ti,Mo)(C,N) and (Ti,W)(C,N) are of interest (see Carbides Transition Metal Solid-state Chemistry), as well as in layer technology where titanium nitride-based coatings of the type Ti(C,B,N) are prepared by magnetron sputtering. Layers consisting of ternary compounds of the type (Ti,Al)N and (Ti,V)N also have favorable properties with respect to abrasion resistance. 

Hartl (26) treated vanadium, chromium, and titanium nitrides in argon-5% acetylene RF plasmas. The nitrides were dropped as powders into a vertical plasma torch in which the gas stream was flowing upwards. Product was collected both as wall deposits and as loose powder at the lower end of the torch (i.e., the plasma gas inlet). In the case of vanadium, the products collected were identified by X-ray analysis to be a mixture of vanadium nitride and carbide (VC-VN) with... 

It is evident from the earlier discussion of the titanium-nitrogen system that the final volatilization temperature (3540 K) was controlled by the complete vaporization of the titanium formed due to the dissociation of the product titanium nitride. The partial pressure of titanium vapor was equal to 0.666 atm at the final volatilization temperature of 3540 K (see Fig. 8). Indeed, the vaporization temperature of titanium at 0.666 atm is 3530 K. Consequently, to analyze the results... 

Numerous ceramics are deposited via chemical vapor deposition. Oxide, carbide, nitride, and boride films can all be produced from gas phase precursors. This section gives details on the production-scale reactions for materials that are widely produced. In addition, a survey of the latest research including novel precursors and chemical reactions is provided. The discussion begins with the mature technologies of silicon dioxide, aluminum oxide, and silicon nitride CVD. Then the focus turns to the deposition of thin films having characteristics that are attractive for future applications in microelectronics, micromachinery, and hard coatings for tools and parts. These materials include aluminum nitride, boron nitride, titanium nitride, titanium dioxide, silicon carbide, and mixed-metal oxides such as those of the perovskite structure and those used as high To superconductors. 

The observed differences in scale thickness and microstructure between the oxide scales and subsurface zones at the various oxidation temperatures seem to be mainly attributed to the different diffusion rates at the respective temperatures. Since the oxidation products formed do not show any differences in the temperature range of 800°C to 1000°C it is concluded that no significant effect of the thermodynamic stability on the composition and structure of the oxidation products occurs. From the calculations of Rahmel and Spencer [21] it is known, however, that the activity of A1 and Ti in the system Ti-Al varies depending on the temperature. Thus it has to be taken into account that the temperature may have an influence on the expansion of the phase fields of some important phases in the system Ti-Al-N-O. Nevertheless it is evidently the temperature which mainly influences the kinetics because the structure of the metal/oxide interface, the formation of titanium nitrides, A127039N and an aluminium depleted metal phase is on principle always very similar. In this way the effect of different temperatures can, to a certain degree, be interpreted as that of a shift in the different stages of the oxidation process. 

Analogously to silicon nitride, titanium nitride precursors can also be prepared by the reaction of titanium tetrachloride with fluid ammonia [89,90]. This leads to the precipitation of highly polymeric products, which can be transferred to metal nitrides or carbonitrides by calcining in ammonia or an inert gas atmosphere. 

Regulation 10/2011/EU of the Commission concerning plastic materials and objects that will come in contact with food products, OJEU, no. L 12/2011, pp. 1-89. A unique substance in the nanometric form is currently featured in the union lisf on line 807. It involves titanium nitride nanoparticles. It indicates that they can be used in PET bottles (for Polyethylene terephthalate) at a maximum of 20 mg/kg . 

Ti2AlN synthesized by the reaction between the mixture of elements did not show positive results. The dominant phases were titanium nitride (TiN) and hexagonal aluminium nitride AIN. Some amount of non-reacted intermetallic phases were also found in the product... 

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