Self-Aligned Interconnection Structure and Method

Abstract

The present disclosure provides a method that includes providing a substrate having a first dielectric material layer and first conductive features that are laterally separated from each other by segments of the first dielectric material layer; depositing a first etch stop layer on the first dielectric material layer and the first conductive features, thereby forming the first etch stop layer having oxygen-rich portions self-aligned with the segments of the first dielectric material layer and oxygen-poor portions self-aligned with the first conductive features; performing a selective removal process to selectively remove the oxygen-poor portions of the first etch stop layer; forming a second etch stop layer on the first conductive features and the oxygen-rich portions of the first etch stop layer; forming a second dielectric material layer on the second etch stop layer; and forming a conductive structure in the second dielectric material layer.

What is claimed is: 
     
         1 . A device comprising:
 a first conductive feature disposed in a first dielectric layer;   a metal oxide layer disposed directly on a top surface of the first dielectric layer;   a non-metal etch stop layer disposed directly on a top surface of the metal oxide layer and a top surface of the first conductive feature; and   a second conductive feature disposed directly on the top surface of the first conductive feature and the top surface of the metal oxide layer.   
     
     
         2 . The device of  claim 1 , further comprising a third conductive feature disposed in the first dielectric layer, wherein the non-metal etch stop layer is disposed directly on a top surface of the second conductive feature. 
     
     
         3 . The device of  claim 2 , wherein the top surface of the second conductive feature extends from a first sidewall of the second conductive feature to a second sidewall of the second conductive feature, the second sidewall opposing the first sidewall, and
 wherein the non-metal etch stop layer completely covers the top surface of the second conductive feature.   
     
     
         4 . The device of  claim 1 , wherein the metal oxide layer includes a sidewall that opposes a sidewall of the second conductive feature, and
 wherein the non-metal etch stop layer extends from the sidewall of the metal oxide layer to the sidewall of the second conductive feature.   
     
     
         5 . The device of  claim 1 , further comprising a second dielectric layer disposed directly on the non-metal etch stop layer, wherein the second conductive feature extends through the second dielectric layer. 
     
     
         6 . The device of  claim 1 , wherein the metal oxide layer includes a material selected from the group consisting of hafnium oxide, zirconium oxide, and aluminum oxide. 
     
     
         7 . The device of  claim 1 , wherein the first conductive feature is a metal line. 
     
     
         8 . A device comprising:
 a first conductive feature and a second conductive feature disposed in a first dielectric layer;   a first etch stop layer disposed directly on a top surface of the first dielectric layer, wherein the first etch stop layer includes a metal oxide material.   a second etch stop layer disposed directly on a top surface of the first etch stop layer, a top surface of the first conductive feature and a top surface of the second conductive feature, wherein the second etch stop layer is free of metal material; and   a third conductive feature disposed directly on the top surface of the first conductive feature and the top surface of the first etch stop layer.   
     
     
         9 . The device of  claim 8 , further comprising:
 a semiconductor substrate; and   a third etch stop layer disposed directly on a top surface of the semiconductor substrate, and   wherein the first conductive feature and the second conductive feature extend through the third etch stop layer to the semiconductor substrate.   
     
     
         10 . The device of  claim 8 , wherein the second etch stop layer completely covers the top surface of the second conductive feature. 
     
     
         11 . The device of  claim 8 , wherein the second etch stop layer extends continuously from the top surface of the second conductive feature to the third conductive feature. 
     
     
         12 . The device of  claim 8 , further comprising a second dielectric layer disposed directly on a top surface of the second etch stop layer, and
 wherein the second etch stop layer is formed a different dielectric material than the second dielectric layer.   
     
     
         13 . The device of  claim 8 , wherein the top surface of the first conductive feature is substantially coplanar with the top surface of the second conductive feature. 
     
     
         14 . The device of  claim 8 , wherein the first etch stop layer has a metal-oxygen bonding concentration of greater than 80%. 
     
     
         15 . A device comprising:
 a first conductive feature and a second conductive feature disposed over a substrate,   first dielectric layer surrounding the first and second conductive features;   a metal oxide layer disposed over the first dielectric layer such that the metal oxide layer physically contacts the first dielectric layer;   a non-metal etch stop layer disposed on the metal oxide layer, the first conductive feature and the second conductive feature such that the non-metal etch stop layer physically contacts the metal oxide layer, the first conductive feature and the second conductive feature; and   a metal feature disposed directly on the first conductive feature.   
     
     
         16 . The device of  claim 15 , wherein the metal feature has opposing sidewall surfaces and the non-metal etch stop layer physically contacts the opposing sidewall surfaces. 
     
     
         17 . The device of  claim 15 , wherein the metal oxide layer includes a first portion having a first sidewall and a second portion have a second sidewall that faces the first sidewall, and
 wherein the metal feature physically contacts the first sidewall of the first portion of the metal oxide layer and wherein the non-metal etch stop layer physically contacts the second sidewall of the second portion of the metal oxide layer.   
     
     
         18 . The device of  claim 15 , wherein the substrate is a semiconductor substrate, and
 wherein at least one of the first and second conductive features physically contacts the semiconductor substrate.   
     
     
         19 . The device of  claim 15 , wherein the non-metal etch stop layer includes a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, and silicon carbide. 
     
     
         20 . The device of  claim 15 , wherein the second conductive feature has a top surface extending from a first sidewall of the second conductive feature to a second sidewall of the second conductive feature, the top surface of the second conductive feature facing away from the substrate, and
 wherein the non-metal etch stop layer completely covers the top surface of the second conductive feature.