Effects of UV curing on the self-forming barrier process of Cu–V alloy films

• We reported the effects of UV curing on the self-forming barrier process.
• Two kinds of low-k dielectrics with or without UV curing were introduced.
• UV curing may play an important role in the formation of a V-based interlayer.

In our previous studies, vanadium (V)-based self-formed barriers were found at the interface between Cu–V alloy films and low-k/Si substrates after annealing at elevated temperatures. In the present work, the diffusion barrier properties of the V-based self-formed interlayer on low-k dielectrics were investigated with and without UV curing treatment. A V-based interlayer on a low-k substrate with UV curing exhibited lower electrical resistivity and higher thermal stability than on a low-k substrate without UV curing. Transmission electron microscopy (TEM) images and energy-dispersive X-ray spectroscopy (EDS) showed that an approximately 4-nm V-based interlayer was found only on the low-k substrates with UV curing after annealing at 300 °C for 1 h. Based on these results, UV curing may play an important role in the formation of a V-based interlayer due to changes in the chemical composition and porosity of the dielectric layer.