A study of the interface phenomena of TiW/Si and TiN/Ti/Si

In device processing, TiW or Ti/TiN is generally used as a barrier metal. Here, we report interesting phenomena at the interface between the barrier metal and Si substrate, depending on the deposition temperature and type of barrier metal, after heat treatment at a temperature of 450/spl deg/C followed by Al deposition. However, the phenomena are not observed below a heat treatment temperature of 400/spl deg/C. To investigate the diffusion barrier characteristic and interface reactions between barrier metal and Si, SEM micrographs, XRD and electron spectroscopy for chemical analysis (ESCA) depth profiles are analyzed.