Metalorganic chemical vapor deposition of Ti-O-C-N thin films using TBOT as a promising precursor

Ti-O, Ti-O-C and Ti-O-C-N thin films have been synthesized successfully via metalorganic chemical vapor deposition (MOCVD) technique. Tetrabutyl orthotitanate (TBOT) is used as a precursor in presence of Ar, H-2, and N-2 as process gases. By controlling deposition temperature and type of process gases, it was possible to control the composition of the deposited films. The deposited films are composed mainly of Ti and O when H-2 is used as a process gas in the temperature range 350-500 degrees C. As the temperature increased up to 600 degrees C, thin films containing anatase (TiO2) and titanium carbide (TiC) phases are deposited and confirmed by XRD and EDX analyses. As the temperature increased to 750 degrees C, a transformation from anatase to rutile phase (TiO2) is started and clearly observed from XRD patterns. Titanium nitride (Ti2N and TiN) phase in addition to TiO2 and TiC phases are formed at 600-1000 degrees C in presence of nitrogen as a process gas. SEM images for all investigated film samples showed that the films are deposited mainly in the form of spherical particles ranged from few nano- to micrometer in size with some additional special features regardless the type of the process gas. Films containing carbon and nitrogen show higher hardness than that containing only oxygen. The obtained results may help in better understanding and controlling film composition and its phase formation in Ti-O-C-N system by MOCVD technique. (C) 2011 Elsevier B. V. All rights reserved.