Transition metal nitride deposition method

A method of depositing a transition metal nitride-containing material on a substrate by a cyclic deposition process, the method comprising:

• providing a substrate in a reaction chamber;
• providing an organometallic transition metal precursor to the reaction chamber in a vapor phase;
• providing an auxiliary reactant to the reaction chamber in a vapor phase;
• and
• providing a nitrogen precursor into the reaction chamber in a vapor phase to form a transition metal nitride on the substrate;
• wherein the transition metal precursor comprises a transition metal from any of groups 4 to 6 of the periodic table of elements,
• wherein the auxiliary reactant comprises a halogen selected from a group consisting of bromine and iodine, and
• wherein the auxiliary reactant comprises a 1,2-dihaloalkane or 1,2-dihaloalkene or 1,2-dihaloalkyne or 1,2-dihaloarene.