Method for manufacturing a semiconductor device and semiconductor device

A semiconductor device comprising:

• an insulating film provided on a substrate;
• and
• a conductive layer buried in a recess formed in said insulating film and made primarily of copper,
• wherein
• at least a part of said insulating film provided at a side of interface with said conductive layer is porositized, and a barrier film made of a metal compound having copper diffusion barrier properties and formed by reaction with said insulating film and a metal other than copper is provided at the interface between said conductive layer and said insulating film.

A method for manufacturing a semiconductor device, which comprising:

• the first step of forming a recess in an insulating film provided on a substrate;
• the second step of subjecting said insulating film to plasma treatment to form, at inner walls of said recess, a modified layer whose density is lower than said insulating film;
• the third step of forming an alloy layer made of copper and a metal other than copper over said modified layer so as to cover the inner walls of said recess;
• the fourth step of burying a conductive layer made mainly of copper in said recess provided thereon with said alloy layer;
• and
• the fifth step of subjecting the resulting substrate to thermal treatment to cause said metal in said alloy layer to react with a constituent component of said modified layer to form a barrier film mad of a metal compound having Cu diffusion barrier properties at an interface between said alloy layer and said modified layer.

A semiconductor device comprising:

• an insulating film provided on a substrate;
• and
• a conductive layer buried in a recess formed in said insulating film and made primarily of copper,
• wherein
• a modified layer whose density is lower than said insulating film is formed at an interface side of said insulating film with said conductive layer, and a barrier film made of a metal compound which is obtained by reaction of said modified layer with a metal other than copper and has copper diffusion barrier properties.