Dielectric barriers for Cu metallization systems

Copper is a promising material to replace aluminum In some microelectronlc applications. However, the interaction of copper with contacting materials in multilevel metallization schemes, especially copper diffusion in dielectrics, is an important issue that needs to be addressed before it can be utilized in certain applications. The influence of different deposition parameters on film properties was studied. Optical and structural properties of deposited films were characterized by ellipsometry and infrared absorption spectroscopy, respectively. The interaction of copper with dielectrics was investigated by different analytical and electrical methods. To accelerate the Cu-migration the samples were exposed to various thermal and electrical stresses. These measurements were performed on MIS structures with Cu dots.