Characterization of TiN thin films grown by low-frequency (60 Hz) plasma enhanced chemical vapor deposition

• DOI: 10.1016/j.jpcs.2012.02.024
• Publication Date: 2012-03-05T19:37:06Z
• Authors: Hong Tak Kim; Maeng Jun Kim; Sang Ho Sohn
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract The characteristics of TiN thin films grown on glass substrates by very low frequency (60 Hz) PECVD were investigated along with the reactive plasma generated using a 60 Hz power source. The TiN film depositions were performed using a gaseous mixture of H2, N2 and TiCl4 onto a substrate positioned between two electrodes using a floating substrate holder with a heating unit. The substrate is electrically floated to avoid sample damages due to ion bombardment. As-grown TiN films showed a NaCl-type fcc structure with a (200) crystallographic plane, low resistivity (∼60 μΩ cm) and gold-like color. Crystallinity was improved, impurities such as O and Cl were reduced, and the atomic ratio of N/Ti became stoichiometric with the increase of substrate temperature. Particularly, no chlorine component was detected above 500 °C. Also, the N2 partial pressure strongly affected the deposition rate and ratio of N/Ti. Otherwise, impurities and crystallinity barely changed with the change of N2 pressure. The atomic ratio of N/Ti, impurities, and crystallinity of the films significantly affected the optical and electrical properties. Consequently, we produced stoichiometric Cl-free TiN films with golden color above 500 °C at 60 mTorr. The effects of temperature played an important role in controlling the film properties compared to the N2 partial pressure.