Patent ID: 6200849
Filing Date: 2001-03-13
Classification: H01L

Abstract:
A method of fabricating conductive contacts to a cell area and to a core area of an integrated circuit memory device, the cell area including a plurality of spaced apart insulated gates, the method comprising the steps of:forming a first interlayer dielectric layer on the cell area and on the core area, including on the plurality of spaced apart insulated gates, the first interlayer dielectric layer including therein a plurality of first contact holes having sidewalls that extend from a face of the first interlayer dielectric layer through the first interlayer dielectric layer, the first contact holes further extending between the plurality of spaced apart insulated gates;forming a first recessed conductive layer in the plurality of first contact holes, between the plurality of spaced apart insulated gates, and recessed beneath the face of the first interlayer dielectric layer;conformally forming a second dielectric layer on the face of the first dielectric layer, on the sidewalls of the first contact holes and on the first recessed conductive layer in the first contact holes;removing at least a portion of the second dielectric layer from on the first recessed conductive layer;forming a second conductive layer in the first contact holes between the second dielectric layer on the sidewalls of the first contact holes;forming second contact holes in the core area, extending through the second dielectric layer and the first dielectric layer;conformally forming a third conductive layer on the second dielectric layer, on the second conductive layer and lining the second contact holes;forming a fourth conductive layer on the third conductive layer in the second contact holes; andforming a bit line on the second conductive layer in a selected one of the first contact holes, the bit line extending onto the second dielectric layer adjacent the selected one of the first contact holes, the bit line being spaced apart from the second conductive layer in the first contact holes that are adjacent the selected one of the first contact holes.