Various embodiments provide an MIM capacitor and fabrication method thereof. An exemplary MIM capacitor can include a dielectric layer disposed over a substrate containing a conductive layer. The dielectric layer can include a groove to expose the conductive layer in the substrate. A first metal layer can be disposed on a bottom surface and a bottom portion of a sidewall surface of the groove. A top surface of the first metal layer on the sidewall surface of the groove can be lower than a top surface of the dielectric layer. A dielectric material layer can be disposed on the first metal layer and on a top portion of the sidewall surface of the groove. A second metal layer can be disposed on the dielectric material layer; and a third metal layer can be disposed on the second metal layer to fill the groove.