Semiconductor memory devices and methods of forming the same

Abstract

According to example embodiments of inventive concepts, method of forming a semiconductor memory devices includes sequentially forming a first mold layer, a first support layer, a second mold layer, and a second support layer on a substrate, forming lower electrodes penetrating the second support layer, the second mold layer, the first support layer, and the first mold layer on the substrate, patterning the second support layer to form a second support pattern including an opening, removing the second mold layer to expose portions of sidewalls of the lower electrodes, and etching the exposed sidewalls of the lower electrodes.

What is claimed is: 
     
         1 . A semiconductor memory device comprising:
 lower electrodes on a substrate;   a capacitor dielectric layer covering surfaces of the lower electrodes;   an upper electrode layer on the capacitor dielectric layer and the lower electrodes;   a first support pattern surrounding middle portions of the lower electrodes; and   a second support pattern surrounding upper portions of the lower electrodes,
 the lower electrodes including sidewalls that define first recessed regions that are adjacent to a bottom surface of the second support pattern, respectively, and 
   each of the first recessed regions of the lower electrodes is laterally recessed toward an inside of one of the lower electrodes.   
     
     
         2 . The device of  claim 1 , wherein
 the sidewalls of the lower electrodes further define second recessed regions that are adjacent to a top surface of the first support pattern, respectively; and   each of the second recessed regions of the lower electrodes is laterally recessed toward the inside of one of the lower electrodes.   
     
     
         3 . The device of  claim 1 , wherein
 each of the first and second support patterns define openings,   sidewalls of the first support pattern in the openings of the first support pattern contacts the lower electrodes, and   sidewalls of the second support pattern in the openings of the second support pattern contact the lower electrode.