Comparison of the Ru thin films grown on Si, TiN/Si and TaN/Si substrates by plasma enhanced atomic layer deposition

High quality Ru thin film with low electrical resistivity (10~14 ¿¿cm) was successfully deposited on the Si, atomic layer deposition (ALD) grown TiN(2nm)/Si and ALD TaN(5 nm)/Si substrates by using plasma enhanced atomic layer deposition (PEALD). Different growth mode and crystallization behavior were observed for the Ru films grown on these different substrates. Results show that the lowest surface roughness, lowest electrical resistivity and best crystallinity of the Ru films can be achieved on all three substrates with a growth temperature of 270°C. Ex and in-situ X-ray diffraction were employed to verify the good diffusion barrier properties of Ru/TiN and Ru/TaN bi-layer structure.