Properties including step coverage of TiN thin films prepared by atomic layer deposition

The physical properties including the step coverage of the TiN films deposited by 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 Å per cycle) under an optimum deposition condition. The film resistivity is appreciably low (200 μΩ cm). The XRD analysis results indicate polycrystalline nature of the TiN films with a (1 1 1) 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 and N by atomic concentration in the TiN films is nearly equal to 1:1 AFM analysis reveals that the RMS surface roughness is low. Also it is found by SEM observation that the step coverage of the TiN films with trenches (the aspect ratio being 10:1) is excellent. One hundred percent conformality is observed for both the side/bottom and the side/top sections.