Semiconductor memory device

Abstract

A semiconductor memory device includes a memory cell portion and a peripheral circuit portion. The memory cell portion includes a pillar capacitor with a lower electrode, a dielectric film, and an upper electrode sequentially formed on a side surface of a first insulating portion which is parallel to a predetermined direction, and a transistor electrically connected to the lower electrode. The peripheral circuit portion includes a plate electrode, a cylinder capacitor with an upper electrode, a dielectric film, and a lower electrode sequentially formed on a side surface of the plate electrode which is parallel to the predetermined direction, and a transistor electrically connected to the lower electrode.

1 . A device comprising:
 an insulating pillar that includes an upper surface, a bottom surface and a side surface between the upper and bottom surfaces;   a first conductive film including a first portion formed on the bottom surface of the insulating pillar and a second portion continuously elongated from the first portion to cover the side surface of the insulating pillar;   an insulating film formed on the second portion of the first conductive film; and   a second conductive film formed on the insulating film;   the first and second conductive films and the insulating film therebetween serving as first and second electrodes and a dielectric film therebetween of a capacitor, respectively.   
     
     
         2 . The device as claimed in  claim 1 , wherein the insulating film is elongated over the upper surface of the insulating pillar beyond a tip portion of the second portion to provide an elongated portion, and the second conductive film extends over the elongated portion of the insulating film. 
     
     
         3 . The device as claimed in  claim 1 , further comprising a conductive plug selectively formed in a first insulating layer, the first portion of the first conductive film being in contact with the conductive plug. 
     
     
         4 . The device as claimed in  claim 3 , further comprising a second insulating film formed between the insulating film and a portion of the first insulating layer around the conductive plug. 
     
     
         5 . The device as claimed in  claim 4 , wherein the insulating pillar is same in material with the second insulating film. 
     
     
         6 . A device comprising:
 an interlayer insulating layer;   a plurality of conductive plugs formed in the interlayer insulating layer apart from one another; and   a plurality of capacitors each formed in contact with an associated one of the conductive plugs;   wherein each of the capacitors comprises:   a lower electrode including a bottom portion and a pipe portion, the bottom portion including a first main surface and a second main surface opposite to the first main surface, the first main surface being in contact with a part of the associated one of the conductive plugs, the second main surface including a first part and a second part surrounding the first part, the pipe portion protruding upwardly from the second part of the second main surface of the bottom portion;   an insulating pillar protruding upwardly from the first part of the second main surface of the bottom portion of the first electrode to fill an inside of the pipe portion of the first electrode;   a dielectric film formed on an outside surface of the pipe portion of the first electrode; and   a second electrode formed on the dielectric film.   
     
     
         7 . The device as claimed in  claim 6 , wherein the second electrodes of the capacitors are in contact with one another to form a plate electrode. 
     
     
         8 . The device as claimed in  claim 7 , wherein the insulating pillars of the capacitors are formed separately from one another. 
     
     
         9 . The device as claimed in  claim 6 , wherein the dielectric film of each of the capacitors is elongated over a top portion of the insulating pillar beyond a tip end of the pipe portion of the first electrode to form an elongated portion; and the second electrode extends to cover the elongated portion of the dielectric film. 
     
     
         10 . The device as claimed in  claim 9 , wherein the insulating pillars of the capacitors are formed separately from one another, and the second electrodes of the capacitors are in contact with one another to form a plate electrode. 
     
     
         11 . The device as claimed in  claim 6 , wherein the dielectric films of the capacitors are formed continuously with one another to form a continuous dielectric film and the second electrodes of the capacitors are formed continuously with one another to form a plate electrode. 
     
     
         12 . The device as claimed in  claim 11 , further comprising an etching stopper film formed around the bottom portions of the first electrodes of the capacitors to intervene between the interlayer insulating layer and the continuous dielectric layer, the etching stopper film and the continuous dielectric layer intervening between the interlayer insulating layer and the plate electrode. 
     
     
         13 . A device comprising:
 a substrate;   an interlayer insulating layer over the substrate; and   a memory cell array comprising a plurality of word lines, a plurality of bit lines, a plurality of memory cells each disposed a different one of intersections of the word and bit lines, a plate electrode, and a plurality of conductive plugs selectively formed in the interlayer insulating layer, each of the memory cells comprising a transistor and a capacitors:   wherein the transistor of each of the memory cells comprises:   a first diffusion region connected to an associated one of the bit lines,   a second diffusion region connected to an associated one of the conductive plugs, and   a gate electrode connected an associated one of the word lines; and   wherein the capacitor of each of the memory cells comprises:   an insulating pillar extending vertically,   a lower electrode including a first portion sandwiched between the insulating pillar and an associated one of the conductive plugs in contact with the insulating pillar and the associated one of the conductive plugs, and a second portion elongated from the first portion vertically along the insulating pillar, and   a dielectric film formed between the second portion of the lower electrode and the plate electrode.   
     
     
         14 . The device as claimed in  claim 13 , wherein the first and second portions of the lower electrode cooperate with each other to continuously surround a substantial whole of a side surface of the insulating pillar with keeping a top portion of the insulating pillar uncovered. 
     
     
         15 . The device as claimed in  claim 14 , wherein the dielectric films of the capacitors are formed continuously with one another to cover the top portion of the insulating pillar of each of the capacitors. 
     
     
         16 . The device as claimed in  claim 15 , further comprising an insulating film formed on portions of the interlayer insulating layer among the first portions of the first electrodes of the capacitors to intervene between the dielectric film and the portions of the interlayer insulating layer. 
     
     
         17 . The device as claimed in  claim 16 , wherein the insulating film is same in material with the insulating pillar. 
     
     
         18 . The device as claimed in  claim 17 , wherein the insulating film comprises a silicon nitride film and the insulating pillar also comprises a silicon nitride film.