The invention discloses a method for realizing a high-performance copper interconnection by an upper mask, comprising a semiconductor substrate with a metal interconnection layer, wherein a compound structure is formed on the metal interconnection layer of the semiconductor substrate, and orderly comprises an etching stop layer, a dielectric layer, an overlying layer and a mask layer from bottom to top. The method for realizing a high-performance copper interconnection by an upper mask disclosed by the invention has the following advantage that: via the technique process and method disclosed by the invention, an added titanium nitride metal hard mask is used as an etching depth adjustment layer for selectively changing the depth of the ditch of a copper interconnection line, so as to reduce the square resistance of the copper interconnection line in a specific area satisfying conditions, thereby realizing a purpose of selectively reducing a chip interconnection resistance. Via the application of the method disclosed by the invention, the interconnection resistance can be furthest reduced on the premise that the whole copper interconnection depth is not changed, the technique difficulty is not increased, and the technique window is not reduced, thereby reducing the signal delay of a chip, reducing loss, and improving the whole performance of the chip.