Semiconductor devices having a copper line layer and methods for manufacturing the same are disclosed. An illustrated semiconductor device comprises a damascene insulating layer having a contact hole, a barrier metal layer including a first ruthenium layer, a ruthenium oxide layer and a second ruthenium layer, a seed copper layer formed on the barrier metal layer, and a copper line layer made of a Cu--Ag--Au solid solution. A disclosed example method of manufacturing a semiconductor device reduces and/or prevents contact characteristic degradation of the barrier metal layer with the silicon substrate or the damascene insulating layer. In addition, by forming the copper line layer made of the Cu--Ag--Au solid solution, long term device reliability may be improved.

A ruthenium-containing thin film is formed. Typically, the ruthenium-containing thin film has a thickness in a range of about from 1 nm to 20 nm. The ruthenium-containing thin film is annealed in an oxygen-free atmosphere, for example, in N.sub.2 forming gas, at a temperature in a range of about from 100.degree. C. to 500.degree. C. for a total time duration of about from 10 seconds to 1000 seconds. Thereafter, copper or other metal is deposited by electroplating or electroless plating onto the annealed ruthenium-containing thin film. In some embodiments, the ruthenium-containing thin film is also treated by UV radiation.