Method of forming barrier films for copper metallization over low dielectric constant insulators in an integrated circuit

摘要

An integrated circuit structure and method of making the same is disclosed, in which the adhesion of copper conductors (12, 22) to a low-dielectric constant insulating layer (10, 16) is improved. During the fabrication of the structure, exposed surfaces of the low-k insulating layers (10, 16), including the surfaces of these layers within contact, via, or trench openings, are exposed to nitrogen gas, preferably in a sputtering chamber. An optional plasma treatment of the insulating layers (10, 16) in the presence of nitrogen gas may also be performed. As a result, the surface portions of the insulating layers (10, 16) is made to be nitrogen-rich. A liner layer (8, 21) is then formed by reactive sputtering of tantalum nitride over the nitrogen-rich surfaces of the insulating layers (10, 16), followed by the sputtering of tantalum. Copper electrodes (12, 22) are then deposited into the openings in the corresponding insulating layers (10, 16) with improved adhesion resulting.