Masaaki Oda

Spin-on Cu films for ultralarge scale integrated metallization

We have developed the spin-on Cu metal (SOM) process to fill trenches and vias down to 0.3 μm. SOM is a liquid material that contains an organic solvent and dispersed ultrafine particles as a source of Cu. This solution was applied to a Si wafer using a spin coater to form a film. Coated wafers were baked at 623–673 K for 10 min in a reducing atmosphere. The end result is a Cu film. Contrary to the conventional deposition techniques, the SOM process is simple but advantageous to its gap filling, planarization, and cost consideration.