TiN(Titanuim nitride) is widely used as diffusion barrier and glue layer in semiconductor industry. TiN has been deposited with PVD method. For the aspect ratio of plug and via-hole is increasing, CVD method which is good step coverage has been proposed for deposition. Due to gas phase reaction, between source and reaction gas, conventional CVD has many drawbacks such as high impurities and poor step coverage. To solve these problems, Cyclic CVD has been proposed. To avoid gas phase reaction in cyclic CVD, reaction gas and source are alternately introduced into reactor. First, source is introduced into reactor and adsorped. Then for purging source inside the reactor Ar gas is injected. $NH_3$ gas is introduced to react with source which is adsorped. Finally, Ar gas has been injected to purge out $NH_3$ gas inside reactor chamber. After this order, 1 cycle has been done. Process variables are source pulse time, source purge time, $NH_3$ pulse time and $NH_3$ purge time in this experiment. The deposition characteristic are different with substrate temperature. Below thermal decomposition temperature, deposition thickness per 1 cycle is saturated to 5Å with source pulse time and higher temperature and higher saturation rate for the adsorption rate is increaced with temperature. Deposition thickness is saturated with $NH_3$ pulse time for $NH_3$ adsorption on TiN deposited. Deposition thickness is constant with source purge and $NH_3$ purge time.
Above thermal decomosition temperature deposition thickness increased with source pulse time like conventional MOCVD. As $NH_3$ pulse and purge time increase, deposition thickness decreased. For the volatile by-product which was generated by reaction between source and $NH_3$ is removed from the substrate. But more experiment is need to prove the exact reason. The resistivity is decreaed with $NH_3$ pulse time because $NH_3$ reacts with source adsorped on substrate unreacted with $NH_3$ to decrease carbon content and close stoicheometry unit. Annealing $NH_3$ ambient, the resistivity would decrease dramatically. The reason is that after annealing crystallization is made and carbon content is decreased. Step coverage is more than 90% at 200℃ and no particle generated.
