Manufacturing method of MIM capacitor

Abstract

The invention discloses a manufacturing method of an MIM capacitor, and relates to the field of semiconductor manufacturing. The manufacturing method of the MIM capacitor comprises the following steps: forming a first metal layer on the surface of a substrate, wherein the first metal layer is used for forming a lower pole plate of the MIM capacitor; forming a dielectric layer on the surface of thefirst metal layer; forming a second metal layer on the surface of the dielectric layer, wherein the second metal layer is used for forming an upper pole plate of the MIM capacitor; sequentially etching the second metal layer, the dielectric layer and the first metal layer to form an MIM capacitor, wherein in the etching process of the first metal layer and the second metal layer, the etching gascomprises CH4, chlorine-based gas or fluorine-based gas, and the first metal layer and the second metal layer are made of tantalum nitride. The problem that a tantalum-containing polymer generated when tantalum nitride is etched through an existing etching process is difficult to remove is solved. The effect of preventing tantalum-containing polymers from remaining in the manufacturing process ofthe MIM capacitor made of tantalum nitride is achieved.

Description

technical field [0001] The present application relates to the field of semiconductor manufacturing, in particular to a method for manufacturing an MIM capacitor. Background technique [0002] Capacitance is an important part of integrated circuits and is widely used in various chips. The structure of the MIM capacitor is a metal layer, an insulating dielectric layer, and a metal layer, and the MIM capacitor can be integrated and formed in the back-end metal interconnection process. [0003] At present, in the manufacturing process of MIM capacitors, materials such as titanium nitride and tantalum nitride can be used for the upper plate and the lower plate. However, when tantalum nitride is used to manufacture MIM capacitors, tantalum (Ta)-containing polymers will be produced during the etching process, and the tantalum-containing polymers will adhere tightly to the substrate, which cannot be removed by wet cleaning, which will damage the device. performance is adversely af...

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Problems solved by technology

However, when tantalum nitride is used to manufacture MIM capacitors, tantalum (Ta)-containing polymers will be produced during the etching process, and the tantalum-containing polymers will adhere tightly to the substrate, which cannot be removed by wet cleaning, which will damage the device. adversely affect the performance of

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