Method for improving metal-insulator-metal capacitor reliability and process structure thereof

Abstract

The invention discloses a method for improving metal-insulator-metal (MIM) capacitor reliability. The method comprises the following steps of sequentially depositing a first metal dielectric layer, a metal layer, a corrosion stopping layer and a second metal dielectric layer on a substrate; forming a first through hole and a second through hole in the second metal dielectric layer and covering a bottom anti-reflex layer on the surface of the second metal dielectric layer; manufacturing a multilayer groove on the second through hole and forming a laminated groove with gradually-increased bottom width; manufacturing the bottom portion of the multilayer groove into a first chamfer, enabling the first through hole to be contacted with the second metal dielectric layer, and manufacturing a connection position between the top end and the multilayer groove into a second chamfer; and etching the first through hole and the second through hole to the surface of the first metal dielectric layer and sequentially forming a top electrode, an insulating film and a bottom electrode on the surface of the second metal dielectric layer from top to bottom. The invention further discloses a process structure of the method for improving the metal-insulator-metal MIM capacitor reliability. The method and the process structure can improve reliability of MIM capacitor devices.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a method for improving the reliability of a metal-insulator-metal capacitor and a process structure thereof. Background technique [0002] MIM (Metal-Insulator-Metal) capacitors are the main form of semiconductor capacitors. At present, the most commonly used capacitor structure is the single-layer capacitor metal-insulating layer-metal plate capacitor model as shown in Figure 1, including the lower plate 71, the insulating film 72 and the upper plate 73; at the same time, many high-density capacitor structures The invention mainly focuses on using different processes to connect more capacitors in parallel per unit area (or volume) to increase the capacitance density, including the lower plate 71, the insulating film 72 and the upper plate 73, such as figure 2 As shown, in the existing capacitor structure, the corners of the lower electrode, the decisive layer and the upper elect...

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Problems solved by technology

At present, the most commonly used capacitor structure is the metal-insulating layer-metal plate capacitor model of the single-layer capacitor structure shown in Figure 1, including the lower plate 71, the insulating film 72 and the upper plate 73; while many high-density capacitor structures The invention mainly focuses on using different processes to connect more capacitors in parallel per unit area (or volume) to increase the capacitance density, including the lower plate 71, the insulating film 72 and the upper plate 73, such as figure 2 As shown, in the existing capacitor structure, the corners of the lower electrode, the insulating layer and the upper electrode of the capacitor are sharp-edged. When the MIM capacitor is working, it is easy to cause sharp discharge and even cause the possibility of breakdown.

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