Method for reducing contact resistance of through hole

Abstract

The invention provides a method for reducing contact resistance of a through hole, which comprises the following steps of: providing a substrate, and forming a dielectric layer on the substrate; etching the dielectric layer to form a through hole in the dielectric layer; forming a first barrier layer on the inner wall of the through hole; carrying out reduction reaction on plasma reaction gas and oxide naturally formed on the surface of the first barrier layer so as to remove the oxide naturally formed on the surface of the first barrier layer; and forming a second barrier layer on the first barrier layer; according to the invention, the plasma reaction gas and the oxide naturally formed on the surface of the first barrier layer are subjected to the reduction reaction to remove the oxide naturally formed on the surface of the first barrier layer, so that the contact resistance of the through hole can be reduced, and the connection quality of a through hole interconnection layer is ensured.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for reducing the contact resistance of through holes. Background technique [0002] In the manufacture of semiconductor integrated circuits, multi-layer metallization technology has produced billions of metal vias, which usually use metal as a connection to form an electrical path between two layers of metal; on the other hand, contact vias The hole technology is also widely used in the connection between silicon devices and the first layer of metal. In the process of the metal barrier layer of the through-hole interconnection layer, it needs to be carried out under vacuum to avoid oxidation of the metal barrier layer by oxygen, which will cause the contact resistance of the through-hole to increase, and the increase in the contact resistance of the through-hole will affect the quality of the interconnection layer. In severe cases, an open circuit may occur. [...

AI Technical Summary

Problems solved by technology

[0003] If the machine works abnormally and the process is interrupted, you must exit the machine and replace it to continue to complete the remaining process

If the interruption occurs when the metal barrier layer is just formed, the surface of the metal barrier layer will be oxidized when exiting the machine at this time, and an oxide layer will be formed on the surf

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