The CVD of Titanium Nitride

All refractory nitrides can be produced as coatings by CVD and, for most of them, CVD remains a major production process. CVD titanium nitride (TiN) is the most important nitride coating from an application standpoint. It is used extensively mainly for wear- and erosion-resistant applications and as a difrusion barrier and antireflection coating in semiconductor devices.l l 

Titanium nitride coatings are produced by reactive sputtering (see Sec. 7.0) and by CVD with titanium tetrachloride as the metal source and either nitrogen gas or ammonia as a source of nitrogen, as foUows  

Reaction 1 is also obtained in a high frequency plasma (13.56 MHz) at 150 Pa pressure and at a low deposition temperature of 500°C. l The availability of two metallo-organic titanium compounds, tetrakis-diethylamino titanium (TDEAT) and tetrakis-dimethylamino titanium (TDMAT) makes possible the deposition of TiN at lower tempera-ture with the following reactions (both at 320°C)  

These low-temperature reactions are being developed for semiconductor applications to replace sputtering. In reaction 4, the level of impurities (C and O2) remains high and reaction 3 is preferred. 

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