Patent ID: 6013550
Filing Date: 2000-01-11
Classification: H01L,Y10S

Abstract:
A method of creating a storage node structure, for a dynamic random access memory (DRAM), capacitor structure, on a semiconductor substrate, comprising the steps of:providing a transfer gate transistor, on said semiconductor substrate, comprised of a polysilicon gate structure, on a gate insulator layer, with a source/drain region, in a region of said semiconductor substrate, not covered by said polysilicon gate structure;forming a storage node contact hole, in a first insulator layer, exposing a source region, of said source/drain region;depositing a first polysilicon layer on the top surface of said first insulator layer, and completely filling said storage node contact hole;forming a storage node opening in a second insulator layer, exposing a portion of the top surface of said first polysilicon layer, in a region in which said first polysilicon overlays a portion of said storage node contact hole;depositing a second polysilicon layer on the top surface of said second insulator layer, on the surfaces of said second insulator, exposed in said storage node opening, and on the portion of said first polysilicon layer, exposed at the bottom of said storage node opening;forming a photoresist plug, in said storage node opening, covering the portion of said second polysilicon layer located on the sides of, and at the bottom of, said storage node opening;removing the portion of said second polysilicon layer, located on the top surface of said second insulator layer, not covered by said photoresist plug, to form a crown shaped storage node structure, underlying said photoresist plug, in said storage node opening;removing said second insulator layer;removing the regions of said first polysilicon layer, not protected by said crown shaped storage node structure, and not protected by said photoresist plug, to create a storage node contact plug structure, comprised of a top portion of said storage node contact plug structure, located underlying said crown shaped storage node structure, and a bottom portion of said storage node contact plug structure, located in said storage node contact hole;removing said photoresist plug;forming a capacitor dielectric layer on the exposed surfaces of said crown shaped storage node structure, and on the exposed surfaces of said storage node contact plug structure; andforming an upper polysilicon electrode, on said capacitor dielectric layer.