Properties and morphology of TiN films deposited by atomic layer deposition

Abstract

In this study, TiN films were deposited on SiO2 substrates by Atomic Layer Deposition (ALD) using TiCl4 and NH3 as precursors. Properties and morphology of the TiN films were characterized by different methods. Using Grazing Incidence X-Ray Diffraction (GIXRD), TiN films demonstrated polycrystalline structure with (111) preferred orientation. Film thickness was measured by Spectroscopic Ellipsometry (SE) and a stable growth rate of 0.0178 nm/cycle was reached after 500 deposition cycles, which was consistent with the essence of ALD as a surface-saturated self-limiting reaction. Film resistivity measured by a four-point probe continuously decreased with increasing deposition cycles until it reached the minimum value of 300 μΩ-cm at 5000 deposition cycles with a thickness of 87.04 nm. The surface roughness and morphology of the TiN films at different deposition cycles ranging from 50 to 400 were analyzed by Atomic Force Microscopy (AFM). The AFM results indicated that the initial film growth follows the Stranski-Krastanov mode.