Damascus technology for forming metal protective layer on copper interconnecting wire

Abstract

The invention relates to the field of semiconductor manufacturing and particularly relates to a Damascus technology for forming a metal protective layer on a copper interconnecting wire. In the Damascus technology, with the covering of the metal protective layer and an etching barrier layer, which can prevent copper from diffusing, on the copper interconnecting wire, the reliability of electron migration and stress migration can be improved, the effective dielectric constant of a dielectric layer between two metal layers is reduced, and formation of the technology control of the metal protective layer on the copper interconnecting wire can be facilitated.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a damascene process with a metal protective layer on copper interconnection lines. Background technique [0002] With the continuous reduction of the feature size of semiconductor integrated circuits, the delay of the resistor capacitor (RC) in the back-end interconnection shows an increasing trend. In order to reduce the RC delay of the back-end interconnection, copper interconnection gradually replaces aluminum interconnection. The mainstream process also introduces low dielectric constant (Low-k) materials. [0003] In the copper interconnection process, due to the high mobility of copper atoms in the dielectric material and silicon, it is easy to diffuse and cause circuit failure. A metal barrier layer that can prevent copper diffusion is deposited on the wall and its bottom, and a dielectric barrier layer that can prevent copper diffusion is deposited on the coppe...

AI Technical Summary

Problems solved by technology

However, usually the dielectric constant of the dielectric etch barrier layer is much higher than that of the introduced low-k material, which is not conducive to the reduction of the effective dielectric constant of the dielectric layer; in addition, the direct grinding of the deposited metal protection layer is also not conducive to the improvement of copper interconnection. The control of the thickness of the metal protection layer on the connection is easy to cause damage to the metal protection layer on the copper interconnection, which in turn affects the electrical uniformity and reliability

Images