Low-impurity, highly conformal atomic layer deposition of titanium nitride using NH 3–Ar–H 2 plasma treatment for capacitor electrodes

Abstract

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% without plasma treatment to 3% with plasma treatment. ALD TiN films formed using plasma posttreatment retained perfect step coverage on trenches with aspect ratios from 8 to 20.