Semiconductor memory device and method for manufacturing same

A semiconductor memory device comprising a plurality of memory transistors each having:

• a floating gate electrode including, in a cross section taken along a bit line direction, a first conductive film in contact with a gate insulating film, first sidewall insulating films opposed to each other across the first conductive film, a second conductive film provided on the first sidewall insulating films and the first conductive film, and a first antioxidation film provided between the first and second conductive films, the first antioxidation film being in contact with the first and second conductive films;
• an interelectrode insulating film provided on the second conductive film;
• and
• a control gate electrode including a third conductive film provided on the interelectrode insulating film, a fourth conductive film provided on the third conductive film, and a second antioxidation film provided between the third and fourth conductive films, the second antioxidation film being in contact with the third and fourth conductive films,
• dimensions of the second and third conductive films along the bit line direction in a cross section being larger than a dimension of the first conductive film along the bit line direction in the cross section.