Plasma-enhanced atomic layer deposition (PEALD) of tantalum nitride (TaN) thin films was investigated at a growth temperature of 230 °C using an alternating supply of tertiary-amylimido-tris(dimethylamido)tantalum (TAIMATA, Ta[NC(CH3)2C2H5][N(CH3)2]3) and hydrogen (H2) plasma. As the H2 plasma power increased from 75 to 175 W, the electrical resistivity of the films was improved from 1900 to 680 μΩ·cm, mainly due to the improved crystallinity. Moreover, the preferred orientation ratio between TaN (200) and TaN (111) planes also abruptly increased from 0.8 to 2.8 with increasing the H2 plasma power. This preferred orientation change of the films from (111) to (200) improves the adhesion properties between Cu and TaN, while the Cu diffusion barrier performance was not significantly affected.
- Copper diffusion barrier
- Plasma-enhanced atomic layer deposition
- Preferred orientation
- Tantalum nitride thin films