Resist Strip and Cu Diffusion Barrier Etch in Cu BEOL Integration Schemes in a Mattson HighlandsTM Chamber

The work described below deals with the process development for stripping the resist and etching the SiC barrier layer from oxide and low-k damascene structures. In the damascene patterning, SiC is used as a barrier layer that prevents Cu to diffuse into the dielectric stacks. The requirements for this barrier etch and strip process are numerous: no chemical modification (k-value), good post etch Cu cleaning properties, good selectivity towards hard masks and good profile control. All experiments were performed in a Mattson Aspen III – Highlands chamber; a low-pressure reactor with biased bottom electrode.