Heterogeneous metallization using solid diffusion removal of metal interconnects

Abstract

A method for forming trenches of an interconnect network in a substrate. The method includes forming a first trench in the substrate, which has a first width. The method also includes forming a second trench in the substrate, which has a second width that is greater than the first width. The method also includes depositing a metal layer into the trenches, applying a dielectric over the metal, and diffusing metal atoms from the trenches to the dielectric. The dielectric absorbs a majority of the metal atoms from the first trench while simultaneously absorbing only a minority of metal atoms from the second trench.

1 . A device having trenches in a substrate, the device comprising:
 a first trench of the trenches in the substrate, wherein the first trench comprises a first width dimension;   a second trench of the trenches in the substrate, wherein the second trench comprises a second width dimension that is greater than the first width dimension;   a first metal layer in first trench and the second trench, wherein the first metal layer comprises first metal atoms in which the first trench devoid of significantly all of the first metal atoms;   a second metal layer in the first trench and the second trench, wherein the second metal layer is located over the first metal present in the first and second trenches; and   a hybrid interconnection structure including the first trench and the second trench, comprised of the first metal layer and the second metal layer, wherein the hybrid interconnection structure is formed simultaneously.   
     
     
         2 . The device of  claim 1 , wherein the first width dimension is less than 30 nm. 
     
     
         3 . The device of  claim 1 , wherein the second width dimension is greater than 30 nm. 
     
     
         4 . The device of  claim 1 , wherein the first trench and the second trench are formed at a same layer or level. 
     
     
         5 . The device of  claim 1 , wherein the first metal layer is comprised of copper or a copper alloy or metal including silver, gold, aluminum, rhodium, iridium, tungsten, molybdenum, cobalt, nickel, ruthenium or metal silicide including tungsten silicide, titanium silicide, nickel silicide, or cobalt silicide. 
     
     
         6 . The device of  claim 1 , wherein the second metal layer is comprised of metal including silver, gold, aluminum, rhodium, iridium, tungsten, molybdenum, cobalt, nickel, ruthenium or metal silicide including tungsten silicide, titanium silicide, nickel silicide, or cobalt silicide. 
     
     
         7 . The device of  claim 1 , further comprising a planarized surface of the hybrid interconnection structure to remove any metal overburden. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . The device of  claim 1 , further comprising a protective layer over the first trench and the second trench. 
     
     
         11 . The device of  claim 1 , further comprising a first barrier layer located at a bottom of the first and second trenches. 
     
     
         12 . The device of  claim 11 , wherein the first barrier layer is comprised of tantalum nitride. 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The device of  claim 1 , wherein the substrate is comprised of a first conductive layer, a diffusion barrier layer, and a second conductive layer. 
     
     
         16 . The device of  claim 15 , wherein a copper-manganese seed is used for a deposition of the first conductive layer. 
     
     
         17 . The device of  claim 15 , wherein the first conductive layer is comprised of copper or a copper alloy. 
     
     
         18 . The device of  claim 15 , wherein the diffusion barrier layer is comprised of tantalum nitride, titanium nitride, pyroxmangite, or tantalum manganese oxide. 
     
     
         19 . The device of  claim 15 , wherein the second conductive layer is comprised of cobalt or a cobalt alloy. 
     
     
         20 . The device of  claim 1 , wherein a dielectric layer is used to absorb the first metal atoms from the first trench.