Cylindrical capacitor

Abstract

A cylindrical capacitor comprising at least a substrate, a cylindrical bottom electrode, a structure layer, a top electrode and a capacitor dielectric layer is provided. The substrate has several plugs. The cylindrical bottom electrodes are disposed on the substrate and electrically connected to the respective plugs. The structure layer surrounds the periphery of each cylindrical bottom electrode. The structure layers that surround the two opposing cylindrical bottom electrodes have no mutual contact while the structure layers that surround two neighboring cylindrical bottom electrodes contact each other. Furthermore, the top electrodes cover the respective cylindrical bottom electrodes and the capacitor dielectric layer is disposed between each top electrode and corresponding cylindrical bottom electrode. Due to the structure layers, the mechanical strength of the whole cylindrical capacitor is improved and the density of the capacitor can be increased.

1 . A cylindrical capacitor, comprising: 
 a substrate having a plurality of plugs formed therein;    a plurality of cylindrical bottom electrodes disposed on the substrate and electrically connected to the respective plugs;    a plurality of structure layers surrounding a periphery of the respective cylindrical bottom electrodes, wherein    the structure layers that surround two opposing cylindrical bottom electrodes have no mutual contact; and    the structure layers that surround two neighboring cylindrical bottom electrodes contact each other;    a plurality of top electrodes covering the respective cylindrical bottom electrodes; and    a capacitor dielectric layer disposed between each top electrode and corresponding cylindrical bottom electrode.    
     
     
         2 . The cylindrical capacitor of  claim 1 , wherein the width of the structure layer is smaller than half the distance between two opposing cylindrical bottom electrodes.  
     
     
         3 . The cylindrical capacitor of  claim 1 , wherein the width of the structure layer is greater than half the distance between two neighboring cylindrical bottom electrodes.  
     
     
         4 . The cylindrical capacitor of  claim 1 , wherein the structure layer includes a silicon nitride layer.