Patent ID: 6051463
Filing Date: 2000-04-18
Classification: H01L

Abstract:
A method for fabricating a data-storage capacitor for a DRAM device fabricated over a semiconductor substrate, with the substrate being already formed with a TFET having a gate and a pair of source/drain regions, the method comprising the steps of:forming a dielectric layer over the substrate, covering the gate and the source/drain regions of the TFET;forming an etch-end layer over the dielectric layer;forming an insulating layer over the etch-end layer;forming a contact hole which penetrates successively through the insulating layer, the etch-end layer, and the dielectric layer to expose a selected one of the source/drain regions of the TFET;depositing a conductive material into the contact hole and over the insulating layer to form a first conductive layer;performing a selective removal process to remove a selected part of the first conductive layer that is laid beyond a predefined range around the contact hole, with the remaining part of the first conductive layer serving as a main conductive trunk;performing an etching process with the main conductive trunk serving as mask to thereby etch the unmasked part of the insulating layer until reaching a predefined depth into the insulating layer but not exposing the etch-end layer;forming an overhanging conductive branch to the main conductive trunk, the overhanging conductive branch and the main conductive trunk in combination constituting a storage electrode which is electrically connected to the selected one of the source/drain regions of the TFET;performing an etching process with the etch-end layer serving as etch-end point to thereby etch away all the remaining part of the insulating layer;forming a dielectric film over all the exposed surfaces of the storage electrode; andforming a conductive block covering all the exposed surfaces of the dielectric film to serve as a cell electrode;wherein the cell electrode, the dielectric film, and the storage electrode in combination constitute the intended data-storage capacitor.