Method for forming cobalt barrier layer and metal interconnection process

Abstract

The present invention provides a method for forming a cobalt barrier layer and a metal interconnection process. The method is performed on a surface of a semiconductor device substrate on which metal interconnection lines and an inter-line dielectric layer are formed, and comprises: depositing a dielectric material film on a surface of the inter-line dielectric layer by atomic layer deposition, to densify the surface of the inter-line dielectric layer; removing the deposited dielectric material film, to expose the metal interconnection lines and the densified surface of the inter-line dielectric layer; selectively depositing cobalt on surfaces of the metal interconnection lines to form a cobalt barrier layer. In the present invention, deposition selectivity of cobalt on surfaces of the metal interconnection lines and the inter-line dielectric layer is improved, thus reducing leakage current between metal interconnection lines and improving yield and reliability of the product.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the priority benefit of China patent application serial No. 201510173198.8, filed Apr. 13, 2015, The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.FIELD OF THE INVENTION[0002]The present invention relates to the field of semiconductor, and particularly to a method for forming a cobalt barrier layer and a metal interconnection process.BACKGROUND OF THE INVENTION[0003]With the development of fabricating process for CMOS integrated circuits and the reduction in critical dimension, novel materials and processes have been applied to device fabricating processes to improve the performance of devices. In a back end process of integrated circuits, Copper (Cu) lines are used to replace Aluminum (Al) lines, and the interconnection resistance is greatly reduced. At the same time, the use of a porous low-k dielectric material can real...

AI Technical Summary

Benefits of technology

This approach improves cobalt deposition selectivity, reducing leakage current and enhancing the yield and reliability of the product by selectively depositing cobalt on metal interconnection lines while minimizing its presence on the dielectric layer.

Problems solved by technology

However, a more amount of cobalt deposited on the dielectric layer means a larger leakage current of between Cu interconnection lines.

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