Semiconductor device and method for manufacturing same

A semiconductor device, comprising:

• a first contact formed of tungsten;
• a second contact formed of aluminum, a lower end portion of the second contact being connected to an upper end portion of the first contact;
• and
• an intermediate interconnection formed of copper and isolated from the first contact and the second contact, a lower face of the intermediate interconnection being positioned higher than a lower face of the first contact, an upper face of the intermediate interconnection being positioned lower than an upper face of the second contact.

A method for manufacturing a semiconductor device, comprising:

• forming a first contact formed of a first conductive material in a first insulating film;
• forming a second insulating film on the first insulating film;
• forming an intermediate interconnection formed of a third conductive material in a portion of the second insulating film isolated from a region directly above the first contact;
• forming a third insulating film on the second insulating film;
• forming a second contact formed of a second conductive material in a portion of the second insulating film and the third insulating film including a region directly above the first contact,
• a diffusion coefficient of the first conductive material with respect to the second conductive material being lower than a diffusion coefficient of the third conductive material with respect to the second conductive material.