Physical Properties of Highly Conformal TiN Thin films Grown by Atomic Layer Deposition

The physical properties of TiN films deposited by the atomic layer deposition (ALD) technique, using TiCl4 and NH3 as the precursors have been investigated. The deposition rate of the TiN film is constant and moderately high (~0.6 A per cycle) under optimum deposition conditions. The film resistivity is significantly low (~200 µΩcm). The X-ray diffraction (XRD) analytical results indicate the polycrystalline nature of the TiN films with a (111) preferred orientation. The XPS and AES analysis results establish that the Cl impurity concentration in the TiN films is lower than 1 at.% and the ratio of Ti to N by atomic concentration in the TiN films is approximately 1:1. SEM observation also revealed that the step coverage of the TiN films with trenches (the aspect ratio being 10:1) is excellent. Conformality of 100% is observed for both the side/bottom and the side/top sections.