Embodiments of the invention generally provide methods for depositing and compositions of tantalum carbide nitride materials. The methods include deposition processes that form predetermined compositions of the tantalum carbide nitride material by controlling the deposition temperature and the flow rate of a nitrogen-containing gas during a vapor deposition process, including thermal decomposition, CVD, pulsed-CVD, or ALD. In one embodiment, a method for forming a tantalum-containing material on a substrate is provided which includes heating the substrate to a temperature within a process chamber, and exposing the substrate to a nitrogen-containing gas and a process gas containing a tantalum precursor gas while depositing a tantalum carbide nitride material on the substrate. The method further provides that the tantalum carbide nitride material is crystalline and contains interstitial carbon and elemental carbon having an interstitial/elemental carbon atomic ratio of greater than 1, such as about 2, 3, 4, or greater.