Semiconductor device having a conductive layer with a cobalt tungsten phosphorus coating and a manufacturing method thereof
A semiconductor device capable of suppressing diffusion of copper at an interface between a copper wire and a cap film to enhance an electromigration resistance to ensure reliability of the copper wire, and a manufacturing method thereof are provided. The semiconductor device according to the present invention comprises an insulating film ( 12 ) formed on a substrate ( 11 ), a concave portion ( 13 ) (for example, a groove) formed in the insulating film, a conductive layer ( 15 ) embedded in the concave portion through a barrier layer ( 14 ), and a cobalt tungsten phosphorus coating ( 16 ) to connect with the barrier layer on the side of the conductive layer and to coat the conductive layer on the opening side of the concave portion.
1. A method of manufacturing a semiconductor device comprising the steps of:
forming a concave portion in an insulating film formed on a substrate;
forming a barrier layer on an inner surface of said concave portion and on a surface of said insulating film and forming a conductive layer on the surface of said insulating film to be embedded in said concave portion through said barrier layer;
removing said conductive layer such that said conductive layer is left in said concave portion and removing said barrier layer on a surface of said insulating film such that a top end of said barrier layer left in said concave portion is between a side of said conductive layer and a side wall of said concave portion; and
forming a cobalt tungsten phosphorus coating to connect with said barrier layer on the side of said conductive layer and to selectively cover said conductive layer on an opening side of said concave portion with electroless plating.
2. The method of manufacturing a semiconductor device according to claim 1 , wherein:
said barrier layer is made of tungsten nitride, and
said barrier layer is removed with wet etching using hydrogen peroxide.
3. The method of manufacturing a semiconductor device according to claim 1 , wherein:
said concave portion is formed into a groove in which a wire is to be formed.
4. The method of manufacturing a semiconductor device according to claim 1 , wherein:
said concave portion is formed into a connecting hole in which a plug connecting one wire to another wire between layers is to be formed.
5. A semiconductor device comprising:
an insulating film formed on a substrate;
a concave portion formed in said insulating film;
a conductive layer embedded in said concave portion through a barrier layer;
a cobalt tungsten phosphorus coating to connect with said barrier layer on a side of said conductive layer and to coat said conductive layer on an opening side of said concave portion;
said barrier layer is formed on a more inner side of said concave portion than said conductive layer, and
said barrier layer and said cobalt tungsten phosphorus coating surround said conductive layer.