Abstract
To study the self-formation mechanism of Ti-rich layers in Cu(Ti) alloy films, the microstructures and electrical resistivities of the Cu(Ti) alloy films were investigated by changing the annealing atmosphere and substrate materials. Oxygen contained in Ar facilitated Ti segregation at the surface, reduced the Ti content in the alloy films, and formed relatively large grains in the alloy films, which are essential for low-resistivity Cu alloy films. For the self-formation of the Ti-rich barrier layer, it was found that the selection of a substrate that is reactive to Ti atoms (forming Ti compounds) was essential. Although a strong reaction of the Ti atoms in the alloy films with SiN compared with that with SiO2 was expected, the resistivities in the annealed Cu(Ti) alloy films on the SiN/Si substrates were higher than those on the SiO2/Si substrates. Further reduction of the resistivities is required for application of the fabrication process to devices.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have