A semiconductor device and method of manufacturing same, capable of preventing the material of a barrier metal layer from penetrating into an intermetallic insulating layer are provided. In an embodiment, the device can include: a first metal interconnection formed in a lower insulating layer on a semiconductor substrate; an intermetallic insulating layer formed on the lower insulating layer including the first metal interconnection, the intermetallic insulating layer having a via hole and a trench for a second metal interconnection connecting to the first metal interconnection; a carbon implantation layer formed on inner walls of the via hole and the trench of the intermetallic insulating layer; a barrier metal layer deposited on the first metal interconnection exposed through the via hole and on the carbon implantation layer; a via formed in the via hole; and the second metal interconnection formed in the trench.