Patent ID: 8129766
Filing Date: 2012-03-06
Classification: H01L

Abstract:
1. A semiconductor memory device comprising: a plurality of transistors on a semiconductor substrate; a first interlayer dielectric film on the transistors; a plurality of first contact plugs in the first interlayer dielectric film, each first contact plug connected to a first diffusion layer of one of the transistor transistors; a plurality of ferroelectric capacitors above the first contact plugs, each ferroelectric capacitor comprising a lower electrode, a ferroelectric film, and an upper electrode; a plurality of second contact plugs in the first interlayer dielectric film, each second contact plug being below an area between two adjacent ferroelectric capacitors and connected to a second diffusion layer of one of the transistors; a plurality of first interconnections connected to the second contact plugs, the first interconnections extending in a first direction substantially perpendicular to a direction of an alignment of the two adjacent ferroelectric capacitors on the first interlayer dielectric film; a second interlayer dielectric film above the first interlayer dielectric film and the first interconnections; a plurality of third contact plugs in the second interlayer dielectric film, the third contact plugs being respectively connected to the first interconnections at positions shifted in the first direction from the second contact plugs; a plurality of second interconnections configured to electrically connect the third contact plugs to upper electrodes of the two adjacent ferroelectric capacitors; linear active areas in a striped pattern on a surface of the semiconductor substrate; and shallow trenches between the active areas, wherein the transistors are in the active areas, the ferroelectric capacitors are above the active areas, the second contact plugs are connected to the first interconnections above the active areas, the first interconnections extend from the active areas toward the trenches, and the third contact plugs are connected to the first interconnections above the trenches.