Damascus copper interconnection technology

The invention discloses a Damascus copper interconnection technology. The technology comprises the steps that a barrier layer, a low k dielectric layer, a low k covering layer and a metal hard mask layer are sequentially formed on the surface of a substrate structure; the metal hard mask layer and the low k covering layer are sequentially etched into the low k dielectric layer, so as to form a copper interconnection trench; back etching is carried out on the residual metal hard mask layer, so as to expand the opening end of the copper interconnection trench; and the subsequent preparation technology of filling a copper diffusion barrier layer and the copper interconnection trench is continued. According to the invention, after the copper interconnection trench is formed through etching, the step of removing a side wall or corner of the metal hard mask in the opening of the copper interconnection trench is added; a subsequent copper material filled in the copper interconnection trench is enough; and without changing a sputtering technology of the copper diffusion barrier layer, the filling ability of the copper interconnection trench is improved, and the device performance is improved.