Patent ID: 8716773

Claim:
A semiconductor device comprising: an interlayer insulating film formed over a semiconductor substrate; a bit line formed on the interlayer insulating film, the bit line including a first metal layer, and a first poly-silicon layer intervening between the first metal layer and the interlayer insulating film, the first poly-silicon layer being directly connected to a bit line connection formation region of the semiconductor substrate; and a transistor including a gate insulating film and a gate electrode, the gate electrode including a second metal layer, and a second poly-silicon layer intervening between the second metal layer and the gate insulating film; wherein a space between the first metal layer and the interlayer insulating film is substantially equal to a space between the second metal layer and the gate insulating film so that the first poly-silicon layer is substantially equal in thickness to the second poly-silicon layer, and the first poly-silicon layer has protrusions that protrude in the depth direction of the semiconductor substrate so as to surround the bit line connection formation region.