Copper interconnection process

The invention relates to the technical field of semiconductor integrated circuit manufacturing, in particular to a copper interconnection process. The copper interconnection process comprises the following steps: providing an interconnection dielectric layer, and forming an interconnection groove in the interconnection dielectric layer; depositing to form a barrier layer, wherein the barrier layer covers the inner wall of the interconnection groove; depositing a copper metal layer, wherein the interconnection groove with the barrier layer is filled with the copper metal layer; removing the upper part of the copper metal layer to form a first groove; removing the barrier layer at the position of the first groove to form a second groove; the upper surface of the residual copper metal layer is oxidized to form a copper oxide layer; and depositing an interlayer dielectric layer, wherein the interlayer dielectric layer covers the interconnection dielectric layer after the second groove is filled with the interlaye