Semiconductor device which increases the capacity of a capacitor without deepening the contact hole

Abstract

There is provided a semiconductor memory device including (a) a semiconductor substrate on which a circuit is formed, (b) a first interlayer insulating film formed on the semiconductor substrate, (c) a plurality of bit lines formed on the first interlayer insulating film, a contact hole being formed through the first interlayer insulating film between adjacent bit lines such that the contact hole reaches the semiconductor substrate, (d) a second interlayer insulating film formed on the first interlayer insulating film such that the second interlayer insulating film covers the bit lines therewith, (e) a first electrically conductive layer buried in the contact hole, a recess being formed through the second interlayer insulating film between adjacent bit lines such that the recess reaches the first electrically conductive layer, and (f) a second electrically conductive layer covering a bottom and an inner sidewall of the recess therewith such that the second electrically conductive layer is electrically isolated from the bit lines. The semiconductor memory device makes it possible to increase a capacity of a capacitor without increasing a depth of a contact hole reaching a peripheral circuit.