| 摘要 |
A semiconductor memory device comprises a plurality of memory cells on a semiconductor substrate, each including a transistor with a pair of impurity diffusion layers and a gate electrode, and a capacitor, a first insulating film covering the transistors, a plurality of parallel extending word lines formed on the substrate, each being connected to the gate electrode of the transistor of at least one selected memory cell, a plurality of bit lines, each connected to one of the pair of impurity diffusion layers of at least one selected memory cell through a first contact hole in the first insulating layer, each bit line formed with a conductive film on a top surface thereof and a second insulating film interposed therebetween, a lower electrode of the capacitor at a predetermined position on the first insulating film electrically connected to one of the bit lines and to the other of the pair of impurity diffusion layers through a second contact hole formed in the first insulating film, wherein the conductive film on the top surface of each of the bit lines is formed by a material having an etching rate lower than that of the first insulating film in etching the first insulating film for the second contact hole.
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