US 6,146,987 AGranted

Method for forming a contact plug over an underlying metal line using an etching stop layer

AssigneesProMOS Tech., Inc., Mosel Vitelic, Inc., Siemens Aktiengesellschaft

InventorsChien-chun Wang, Eddie Chiu, Chung-Yi Chen, Hsien-Yuan Chang

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Abstract

A method for forming a contact plug that lands on a metal line of an interconnect structure formed on a semiconductor substrate. First, a first insulating layer is formed atop the substrate and between gaps in the interconnect structure. Next, an etching stop layer is formed on the first insulating layer. A second insulating layer is formed atop the etching stop layer. The second insulating layer is patterned and etched, stopping at the etching stop layer, to form a contact opening. The portion of the etching stop layer left exposed by the contact opening is removed. Finally, a barrier metal layer is formed along the walls of the contact opening and a conducting layer is deposited into the contact opening.

Claims7

Dependent claims

A method for forming a contact plug that lands on a metal line of an interconnect structure formed on a semiconductor substrate, the method comprising the steps of:

forming a first insulating layer atop said substrate and between gaps in said interconnect structure;
forming an etching stop layer on said first insulating layer and atop said metal lines of said interconnect structure;
forming a second insulating layer atop said etching stop layer;
patterning and etching said second insulating layer, stopping at said etching stop layer, to form a contact opening;
removing a portion of said etching stop layer left exposed by said contact opening;
forming a barrier metal layer along the walls of said contact opening;
and
forming a conducting layer into said contact opening and atop said barrier metal layer.

5 more elements

Dependencies are inferred from the claim text.