Patent ID: 6297121
Filing Date: 2001-10-02
Classification: H01L

Abstract:
A method of forming a capacitor, comprising:providing a semiconductor substrate having devices formed therein;forming a layer of first dielectric on said semiconductor substrate;forming a contact hole having a bottom, a top, and sidewalls in said layer of first dielectric thereby exposing a contact region in said semiconductor substrate at said bottom of said contact hole, wherein said top of said contact hole is larger than said bottom of said contact hole;forming a layer of first conducting material on said sidewalls and said bottom of said contact hole;forming spacers of second dielectric on that part of said layer of first conducting material formed on said sidewalls of said contact hole thereby leaving a center cavity in said contact hole;filling said center cavity of said contact hole with a second conducting material, thereby forming a center pillar of said second conducting material, and whereby said contact hole is completely filled with said first conducting material, said spacers of second dielectric, and said center pillar of said second conducting material, wherein said center pillar of said second conducting material contacts said first conducting material at said bottom of said contact hole;removing said spacers of said second dielectric without removing any of said first dielectric;forming a layer of third dielectric on said semiconductor substrate, thereby covering said conducting material on said sidewalls of said contact hole and said center pillar with said third dielectric and leaving a side cavity surrounding said center pillar; andforming a layer of third conducting material over said layer of third dielectric thereby filling said side cavity with said third conducting material wherein said third conducting material forms a top capacitor plate.