A kind of etching method of tantalum nitride tan film

Abstract

The invention provides an etching method of tantalum nitride TaN film, comprising the steps of a, in a first period, introducing first etching gas into a reaction chamber such that TaN and the first etching gas engage in interfacial reaction to generate a first etching product; b, in a second period, introducing second etching gas into the reaction chamber; c, cyclically executing the steps a and b until TaN is completely removed; in the TaN etching method provided herein, it can be guaranteed in the whole etching process that different areas of the TaN film are at uniform etching rate, and therefore after etching of the whole TaN film material, both cases are avoided that a local area experiences over-etching and the layer structure below the TaN film is damaged by over-etching. Therefore, compared with the prior etching method, the etching method provided herein can provide increased compatibility for the etching process and increased yield for products.

Description

technical field [0001] The invention relates to the field of semiconductor processing technology, in particular to an etching method for a tantalum nitride TaN thin film. Background technique [0002] In deep submicron integrated circuits, tantalum nitride (TaN) is a commonly used material layer in metal interconnect structures. This is because tantalum nitride is currently the ideal diffusion barrier material for preventing metal diffusion. [0003] In the process of depositing thin films, reactive ion sputtering (Reactive Ion Sputtering) is a common method for preparing TaN (tantalum nitride) thin films. However, due to the characteristics of the sputtering deposition process, the TaN thin film is mainly composed of columnar structure grains of tantalum fluoride chemical components in various chemical states, and there are intercrystalline regions of amorphous state and chemical composition segregation between the grains. XRD detection shows that the TaN film deposited b...

AI Technical Summary

Problems solved by technology

Therefore, during the etching process, due to the inhomogeneity and anisotropy of the etching rate on the entire film, there will be over-etching in some areas, especially the grain boundary area, and due to the inhomogeneity and anisotropy The rate will further deteriorate as the process progresses in the etch

The over-etching phenomenon will cause the etching of the film under the TaN film, thereby transferring the etching damage to the underlying structure, and the damage will be further aggravated due to the bombardment of ions

Uneven etching and damage to the underlying film will affect the compatibility of the etching process and greatly reduce the product yield

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