Characteristics of TiN thin films grown by ALD using TiCl₄ and NH₃

Titanium nitride thin film was deposited on a silicon wafer by the Atomic Layer Deposition (ALD) method using TiCl₄ and NH₃ as source chemicals. Nitrogen gas was used for carrying the TiCl₄ and purging the reactants. The gases were introduced into the reaction chamber in the sequence of TiCl₄-N₂-NH₃-N₂ for the saturated surface reaction on the wafer. TiN film was grown with [100] preferred orientation at 350°C, while with [111] preferred orientation at 450°C and higher temperatures. The deposition rate was constant as 0.17 Å/ cycle irrespective of deposition temperature, which demonstrates TiN film was grown by the ALD growth mechanism. TiN thin films grown at a temperature higher than 450°C with thickness of 320 Å showed electrical resistivity as low as 72×10^-6Ωcm.