Fabrication Method of Semiconductor Integrated Circuit Device

Abstract

The following defects are suppressed: when an interlayer insulating film including a silicon carbide film and an organic insulating film is dry-etched to form interconnection grooves over underlying Cu interconnections, an insulating reactant adheres to the surface of the underlying Cu interconnections exposed to the bottom of the interconnection grooves, or the silicon carbide film or the organic insulating film exposed to the side walls of the interconnection grooves are side-etched. When a lamination film made of a silicon oxide film, an organic insulating film, a silicon oxide film, an organic insulating film and a silicon carbide film is dry-etched to form interconnection grooves over Cu interconnections, a mixed gas of SF6 and NH3 is used as an etching gas for the silicon carbide film to work side walls of the interconnection grooves perpendicularly and further suppress defects that a deposit or a reactant adheres to the surface of the Cu interconnections exposed to the bottom of the interconnection grooves.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a technique on fabrication of a semiconductor integrated circuit device, particularly a technique effective for the formation of a copper interconnection, using Damascene process. [0002] In recent processes of fabricating a semiconductor integrated circuit device wherein circuits are made highly fine and integrated to a very high degree, element-isolating trenches are made in a silicon substrate or contact holes are made in self-alignment to gate elements of metal insulator semiconductor field effect transistors (MISFETs), for example, by using a difference in etching speed between different kinds of insulating films, such as a silicon oxide film and a silicon nitride film. [0003] Japanese Patent Unexamined Publication No. Hei 10(1998)-321838 discloses a technique of depositing a silicon oxide film across a silicon carbide (SiC) film over a gate electrode to which a side wall spacer made of a silicon oxide film or a...

AI Technical Summary

Benefits of technology

[0015] An object of the present invention is to provide a technique making it possible to suppress the following defects: when an interlayer insulating film including a silicon carbide film and an organic insulating film is dry-etched to form interconnection grooves over underlying Cu interconnections, an insulating reactant adheres to the surface of the underlying Cu interconnections exposed to the bottom of the interconnection grooves and further the silicon carbide film or the organic insulating film exposed to side walls of the interconnection grooves is side-etched.

Problems solved by technology

However, the following defects were generated: an insulating reactant adhered to the surface of the underlying Cu interconnections exposed to the bottom of the interconnection grooves and further the silicon carbide film or the organic insulating film exposed to side walls of the interconnection grooves was side-etched.

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