| 摘要 |
Provided is a method for forming a Cu wiring structure which can suppress an increase in the permittivity of an entire wiring structure, can enhance oxygen barrier characteristics of Cu wiring, can enhance the selectivity of a cap film for a Cu film, and can enhance the electromigration resistance of Cu wiring. The method for forming a Cu wiring structure comprises: forming a barrier film (204) at least in a trench (203) formed in an inter-layer insulating film (202); burying a Cu alloy film (206) made of Cu-Al alloy; forming an additional layer (207) on the Cu alloy film (206); forming Cu wiring (208) in the trench (203) by polishing the entire surface by a CMP; forming a cap layer (209) made of a Ru film on the Cu wiring (208); forming an interfacial layer (210) including Ru-Al alloy around the interface with the cap layer (209) of the Cu wiring (208) using the heat used when the cap film was formed; and forming an inter-layer insulating layer (211) on the interfacial layer (210). |
