Method for fabricating a metal-insulator-metal capacitor

A method for fabricating a metal-insulator-metal (MIM) capacitor comprising:

• providing a substrate having a dielectric layer thereon;
• forming at least one dual damascene opening and at least one MIM capacitor opening within the dielectric layer;
• forming a barrier layer on the dielectric layer, the sidewall and bottom of the MIM capacitor, and the dual damascene opening;
• forming a seed layer on the barrier layer surface;
• forming a first copper layer on the seed layer, in which the thickness of the copper layer covering bottom of the MIM capacitor is smaller than the thickness of the dielectric layer;
• forming an insulating layer on the surface of the first copper layer;
• forming a second copper layer on the insulating layer surface and completely filling the MIM capacitor opening;
• and
• performing a planarization process to remove the second copper layer formed on the dielectric layer, the insulating layer, and the first copper layer for forming an MIM capacitor in the MIM capacitor opening and a dual damascene conductor in the dual damascene opening.