Method of forming dielectric capping layer for copper interconnect

Abstract

The invention provides a forming method of a copper-interlinked dielectric covering layer. The forming method includes: providing a semiconductor substrate; forming a low K dielectric layer and a copper-interlinked structure positioned in the low K dielectric layer on the semiconductor substrate; etching the low K dielectric layer to enable height of the top face of the low K dielectric layer to be smaller than that of the top face of the copper-interlinked structure; depositing an amorphous Si layer on the surface of the low K dielectric layer and the copper-interlinked structre; introducing a first gas source to treat the amorphous Si layer to form a silicon-enriched SiN layer; performing annealing treatment to form a CusiN layer on the surface of the copper-interlinked structure; introducing a second gas source to treat the surfaces of the low K dielectric layer and the copper-interlinked structure to enable the amorphous Si layer to be completely converted into a SiN layer and to fully form the CuSiN layer on the surface of the copper-interlinked structure; depositing on the SiN layer to form the dielectric covering layer. By the forming method, reliability of devices can be ensured, electromigration characteristics of copper interlinking are improved, influence on electromagnetic characteristics of copper interlinking is avoided, and the problem that bad influence is generated on the electromagnetic characteristics due to the fact that an interface covered by a sharp corner is uneven is solved.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a method for forming a copper interconnect dielectric covering layer. Background technique [0002] With the development of integrated circuits, the feature size continues to decrease, and the current density of metal wires increases sharply; at the same time, the increase in chip integration leads to increased power consumption per unit area. Therefore, the reliability of metal wiring has always been an important issue in IC design. and important issues of concern to manufacturing. In metal wires, electrons moving in the opposite direction of the electric field exchange momentum with metal ions, resulting in diffusion-dominated mass transport of metal ions, a phenomenon known as electromigration. Electromigration is an important metal failure mechanism in interconnect structures of semiconductor devices. There are two types of failures caused by electromigration, which ...

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Problems solved by technology

Unsmooth interfaces will have a greater impact on the electromagnetic properties of copper interconnects

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