Metal diffusion barrier layer structure and forming method thereof

Abstract

The invention discloses a metal diffusion barrier layer structure. The metal diffusion barrier layer structure comprises an adhesion layer, a molybdenum disulfide barrier layer, a seed crystal layer and a wire layer which are sequentially formed in a groove or a hole from outside to inside, wherein the molybdenum disulfide barrier layer is formed by permeating sulfur into the copper-molybdenum alloy seed crystal layer and reacting the sulfur with molybdenum in the copper-molybdenum alloy seed crystal layer. The three-dimensional molybdenum disulfide layer is used for replacing traditional tantalum nitride to serve as the metal diffusion barrier layer, the thickness of the barrier layer can be greatly reduced, the proportion of wire metal is increased, good electrical conductivity is achieved, and therefore the metal interconnection resistance can be greatly reduced on the whole, the electromigration resistance of the copper wire is improved, and the problems of groove coverage rate, process compatibility and the like due to introduction of a two-dimensional material in a subsequent process are effectively solved.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuit technology, in particular to a metal diffusion barrier layer structure and a forming method that can be used in subsequent interconnection technologies. Background technique [0002] In the advanced semiconductor integrated circuit process technology, the process technology of using metal copper (Cu) as the conductor wiring material and Low-k dielectric as the interlayer medium is widely used to reduce the transmission delay (RC delay) in the subsequent interconnection. )Phenomenon. However, as the size of wires continues to shrink, the reliability of copper interconnection becomes more and more serious: high current density leads to the reduction of copper electromigration (EM) life, and copper is easy to diffuse into Low-k dielectrics during the process , causing the device to short circuit. [0003] In order to alleviate the reliability problem of copper interconnecti...

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Problems solved by technology

[0005] (1) Two-dimensional materials have low coverage in three-dimensional trenches and vias with complex structures

[0006] (2) In the preparation process of traditional two-dimensional materials, a higher deposition temperature is required, so there is a problem of incompatibility with the subsequent thermal budget

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