Low-impurity, highly conformal atomic layer deposition of titanium nitride using NH_3-Ar-H_2 plasma treatment for capacitor electrodes

摘要

The atomic layer deposition (ALD) of titanium nitride (TiN) films using tetrakis(dimethylamido)titanium and ammonia (NH_3) with and without NH_3-Ar-H_2 plasma posttreatment was evaluated. Based on the saturation mechanism, the growth rate with and without plasma treatment was saturated at 0.24 and 0.46 nm/cycle, respectively. Plasma-treated TiN films had nanocrystalline structures, and the root-mean-square thickness was 0.211 nm. Carbon impurities decreased from 12 percent without plasma treatment to 3 percent with plasma treatment. ALD TiN films formed using plasma posttreatment retained perfect step coverage on trenches with aspect ratios from 8 to 20.