US Patent 7755192 Copper interconnection structure, barrier layer including carbon and hydrogen

A copper interconnection structure includes an insulating layer, an interconnection and a barrier layer. The insulating layer includes silicon (element symbol: Si), carbon (element symbol: C), hydrogen (element symbol: H) and oxygen (element symbol: O). The interconnection is located on the insulating layer, and the interconnection includes copper (element symbol: Cu). The barrier layer is located between the insulating layer and the interconnection. The barrier layer includes an additional element, carbon (element symbol: C) and hydrogen (element symbol: H). The barrier layer has atomic concentrations of carbon (element symbol: C) and hydrogen (element symbol: H) maximized in a region of a thickness of the barrier layer where the atomic concentration of the additional element is maximized.