Characteristics and compositional variation of TiN films deposited by remote PEALD on contact holes

TiN films were deposited by remote plasma-enhanced atomic layer deposition (PEALD) and a metalorganic chemical vapor deposition (MOCVD) method with post-plasma-treatment using the same precursor, tetrakis (dimethylamino)titanium (TDMAT), as a Ti source. In remote PEALD, the plasmas of hydrogen, nitrogen, and ammonia were used, while in MOCVD, the ammonia gas was used as a reactant and followed by the post-plasma-treatment with hydrogen or nitrogen. The TiN films deposited by remote PEALD showed a relatively constant compositional variation with carbon impurity contents less than 5 atom %. The TiN film exhibited amorphous phase at annealing temperatures up to 500degreesC and transferred to a crystalline phase after annealing above 550degreesC. The measured growth rate of TiN films was about 2theta per cycle. The TiN films also showed excellent step coverage above 95% with a very high aspect ratio structure. The TiN film deposited by remote PEALD exhibited almost uniform compositional variation in depth with less than 3 atom % carbon impurity at the top and side of contact hole. However, the TiN films deposited by MOCVD with post-plasma-treatment showed nonuniform compositional variations depending on the positions with about 5 and 10 atom % carbon impurity at the top and side on contact hole, respectively. (C) 2004 The Electrochemical Society.