Semiconductor device and method for manufacturing the semiconductor device

A semiconductor device comprising:

• an interconnect including (i) a first layer, and (ii) a second layer provided on the first layer and including copper;
• and
• a plug provided on the interconnect and including (a) a third layer including titanium and nitrogen, and (b) a fourth layer provided on the third layer and including tungsten, wherein
• the first layer includes an upper end that is in contact with the third layer, and
• the first layer has a nitrided portion at the upper end that is in contact with the third layer.

A method for manufacturing a semiconductor device, comprising:

• forming an interconnect including (i) a first layer, and (ii) a second layer provided on the first layer and including copper;
• and
• forming a plug on the interconnect such that the plug includes (a) a third layer including titanium and nitrogen, and (b) a fourth layer provided on the third layer and including tungsten,
• wherein the forming of the third layer includes supplying a first gas including titanium and chlorine, and supplying a second gas including nitrogen and hydrogen after supplying the first gas.