| US 7,615,814 B2 | ||
| Ferroelectric device having a contact for taking the potential of a metal film and a plurality of capacitors positioned periodically | ||
| Atsushi Noma, Osaka (Japan); and Toyoji Ito, Toyama (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Feb. 06, 2007, as Appl. No. 11/702,536. | ||
| Claims priority of application No. 2006-159570 (JP), filed on Jun. 08, 2006. | ||
| Prior Publication US 2007/0284636 A1, Dec. 13, 2007 | ||
| Int. Cl. H01L 27/115 (2006.01) | ||
| U.S. Cl. 257—295 [257/E27.104; 257/296; 257/306; 257/303] | 6 Claims |
| 1. A semiconductor memory device comprising:
a first conductive layer and a second conductive layer formed apart from each other in a semiconductor substrate;
a first insulating film formed on the semiconductor substrate, the first conductive layer, and the second conductive layer;
a first plug penetrating the first insulating film and connected at its bottom end to the first conductive layer;
a second plug penetrating the first insulating film and connected at its bottom end to the second conductive layer;
a second insulating film formed over the first insulating film and having at least a first opening and a second opening, the
first opening being located above the first plug, the second opening being located above the second plug;
a first metal film formed on at least the bottom and side wall of the first opening and electrically connected to the first
plug;
a second metal film formed on at least the bottom and side wall of the second opening and electrically connected to the second
plug;
a first capacitor insulating film made of a ferroelectric film formed on at least the first metal film;
a second capacitor insulating film made of a ferroelectric film formed on at least the second metal film; and
a third metal film formed to extend onto the tops of the first and second capacitor insulating films and across an area between
the first and second openings, wherein:
the second metal film has an extending portion on the top surface of the second insulating film, the extending portion extending
from the second opening in a direction away from the first opening,
the second metal film is connected at its extending portion to the third metal film,
a plurality of first structures each including the first conductive layer, the first plug, the first opening, the first metal
film, and the first capacitor insulating film are formed to be arranged at regular intervals in an area located opposite to
a second structure including the second conductive layer, the second plug, the second opening, the second metal film, and
the second capacitor insulating film,
the distance between the second opening and a first opening of the plurality of first opening which is located in one end
of a region formed with the plurality of first openings is identical to the distances between the plurality of first openings,
the one end adjoining the second opening, and
the first openings and the second opening have the same diameter.
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