Patent ID: 6211091
Filing Date: 2001-04-03
Classification: H01L

Abstract:
A method for forming a node contact in a self-aligned fashion, which applies on a substrate, a first insulating layer is formed; and a plurality of node contact plugs are formed within the first insulating layer, the method comprising:forming a second insulating layer on the first insulating layer;forming a conductive layer on the second insulating layer;forming a third insulating layer on the conductive layer;patterning the third insulating layer and the conductive layer to form a plurality of bit line stacks;forming a fourth insulating layer on the substrate, wherein materials used as the fourth and the second insulating layers are similar;performing a first anisotropic removal process to remove portions of the fourth and second insulating layers so that spacers are formed on the sidewalls of each bit line stack and upper surfaces of the node contact plugs are exposed;forming a stop layer on the substrate;forming a planarized fifth insulating layer on the stop layer;performing a second removal process to remove portions of the fifth insulating layer so that a plurality of openings are formed and upper surfaces of the stop layer above the node contact plugs are exposed;performing a third removal process to remove exposed portions of the stop layer so that a remaining portion of the stop layer forms second spacers covering a portion of the first spacers and a portion the node contact plugs between the second spacers is exposed; andfilling the openings with a conductive material to form a plurality of node contacts.