Different SiH4 treatments of CVD TiN barrier layers

A cyclic MOCVD TiN deposition process of alternating deposition and plasma treatment steps was modified to deposit Si stabilized TiN barriers for copper metallisation schemes. SiH4 plasma or soak treatments were introduced at different points in the multistep process. In case of the SiH4 plasma treatments, the film thickness was drastically increased because of the deposition of Si interlayers. Furthermore, no densification effect of the TiN pyrolysis layer is detected for the SiH4 plasma treatment, compared to the H2/N2 plasma. The influence of the presence of Si to the following deposition cycle is evident. Only the silane soak led to moderate thickness and resistivity increase compared to the TiN films.