Semiconductor device and production method therefor

A semiconductor device production method for producing a semiconductor device in which a first interconnection layer and a second interconnection layer stacked with an intervention of an interlevel insulation film are electrically connected to each other through an interlevel connection opening formed in the interlevel insulation film, the method comprising the steps of:

• forming the first interconnection layer on a semiconductor substrate;
• forming the interlevel insulation film to cover the first interconnection layer;
• forming the interlevel connection opening at a predetermined position in the interlevel insulation film to expose a part of the first interconnection layer;
• forming a barrier layer in the interlevel connection opening, the barrier layer having a laminate structure including a first sublayer provided in contact with the first interconnection layer to reduce a contact resistance, a second sublayer provided in contact with the second interconnection layer to improve a bonding strength, and a third sublayer provided between the first sublayer and the second sublayer;
• and
• forming the second interconnection layer from gold as an uppermost interconnection layer in contact with the barrier layer on the interlevel insulation film.