Rapid thermal chemical vapor deposition of titanium nitride for barrier application

Today there are many investigations of titanium nitride (TIN) deposition as diffusion barriers in microelectronics, especially with Chemical Vapor Deposition (CVD) techniques. In our newly developed Rapid Thermal CVD (RTCVD) process, we combine the conventional LPCVD process of TiN using titanium (IV) chloride and ammonia with the advantages of a RTCVD reactor. With regard to the ability of fast temperature change especially to reach the anneal temperature and to cool down to room temperature in the annealing ambient, it is possible to perform the entire processing sequence within one single processing chamber. The influences of deposition temperature, as well as the effects of the temperature during a subsequent in situ anneal step on the properties of the layers is analyzed. TIN layers with a specific resistivity as low as 250 my-Omega-cm even at deposition temperatures of 450 Cel are obtained. The resistivity of the layers and the chlorine content is nearly half of the films without an anneal step. The capability of these layers for ULSI application is shown by depositing TiN in submicron contact holes with a step coverage of nearly 100%.