Method for monitoring pollutants in reaction cavity of ion implantation machine

Abstract

The invention discloses a monitoring method for pollutants in a reaction cavity of an ion implantation machine. The monitoring method comprises the following steps: obtaining a standard dielectric layer etching rate in advance; providing a substrate with a dielectric layer, and measuring to obtain a first thickness value of the dielectric layer; placing the substrate on which the dielectric layeris formed in the reaction cavity of the ion implantation machine for ion implantation; etching the dielectric layer on the substrate after ion implantation, and measuring the dielectric layer to obtain a second thickness value of the dielectric layer; and obtaining the etching rate of the dielectric layer according to the first thickness value, the second thickness value and the set etching time when the dielectric layer is etched, and comparing the etching rate of the dielectric layer with the standard etching rate of the dielectric layer. The problem that a wafer is damaged due to the changeof the etching rate of the product can be solved.

Description

technical field [0001] The invention relates to the technical field of integrated circuit manufacturing, in particular to a method for monitoring pollutants in a reaction chamber of an ion implantation machine. Background technique [0002] During the long-term use of the ion implantation machine, many pollutants will be formed in the reaction chamber, and these pollutants are often formed with many uncertainties. Some of the pollutants will interact with the wafers in the reaction chamber. The reaction of polysilicon changes the chemical properties of polysilicon, resulting in subsequent etching of polysilicon, and its etching rate will change, causing irreversible damage to the product. For example, due to changes in the chemical properties of polysilicon, the etching rate becomes faster when the polysilicon is subsequently etched, so that under the same etching conditions, the polysilicon is over etched, and the oxide layer under the polysilicon is over etched. Etching o...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for monitoring pollutants in the reaction chamber of an ion implantation machine, which is used to monitor the situation of pollutants in the reaction chamber of an ion implantation machine, and solve the problem of damaging the wafer due to the change of the etching rate of polysilicon

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