Patent ID: 6171968
Filing Date: 2001-01-09
Classification: H01L

Abstract:
A method of forming a damascene structure having borderless via design, the method comprising the steps of:providing a substrate structure;forming a first conductive line over the substrate structure;forming a first dielectric layer over the first conductive line and the substrate structure, wherein the first dielectric layer has an opening that exposes a portion of the first conductive line;forming a plug in the opening such that the plug is electrically connected to the first conductive line;forming an insulating layer and then a second dielectric layer over the first dielectric layer;patterning the second dielectric layer and the insulating layer to form a trench that exposes a portion of the plug, wherein a sidewall of the insulating layer in the trench is naturally exposed;removing a portion of the insulating layer from the sidewall of the insulating layer within the trench, so as to form a cavity region, which further expose the plug;forming a conductive layer over the second dielectric layer that also fills the trench and the cavity region, wherein the cavity region allows the conductive layer to have a larger contact area to the plug than that in the trench; andplanarizing the conductive layer to remove excess conductive material over the second dielectric layer, hence forming a second conductive line in the trench and the cavity region, wherein the second conductive line is electrically coupled to the plug.