Effect of Post-Treatments on Atomic Layer Deposition of TiN Thin Films Using Tetrakis(dimethylamido)titanium and Ammonia

The atomic layer deposition (ALD) of TiN thin films from tetrakis(dimethylamido)titanium (TDMAT) and NH3 has been investigated, and the properties of ALD TiN films with and without post-treatments such as rapid thermal nitridation (RTN) and H2/N2 plasma treatment were evaluated and compared with those of MOCVD TiN with and without RTN. Based on the saturation of the deposition rate as a function of TDMAT pulse time, the linear relationship between film thickness and the number of cycles, and the perfect step coverage, the success of the ALD process for TDMAT and NH3 was confirmed. For the ALD TiN film, an aging effect was observed, and the C in the film was removed by RTN. Also, by plasma treatment, C and O removal and surface nitridation were accomplished, leading to the prevention of the aging effect, lower resistivity, and slight crystallinity. Cracks and voids were found on the ALD TiN film surface treated by RTN at 700 C substrate temperature, however, they were not found for MOCVD TiN film. 8 refs.