High-nitrogen content metal resistor and method of forming same

Abstract

A thin film metal resistor is provided that includes an in-situ formed metal nitride layer formed in a lower region of a metal nitride layer. The in-situ formed metal nitride layer, together with the overlying metal nitride layer, from a thin film metal resistor which has a nitrogen content that is greater than 60 atomic % nitrogen. The in-situ formed metal nitride layer is present on a nitrogen enriched dielectric surface layer. The presence of the in-situ formed metal nitride layer in the lower region of the metal nitride layer provides a two-component metal resistor having greater than 60 atomic % nitrogen therein.

What is claimed is: 
     
         1 . A metal resistor structure comprising:
 a dielectric material layer having a nitrogen enriched dielectric surface layer located in an upper region thereof; and   a metal nitride layer located atop said nitrogen enriched dielectric surface layer, wherein said metal nitride layer is separated from said nitrogen enriched dielectric surface layer of said dielectric material layer by an in-situ formed metal nitride layer.   
     
     
         2 . The metal resistor structure of  claim 1 , wherein said metal nitride layer and said in-situ formed metal nitride layer comprise a bilayer resistor with a distinct interface located therebetween. 
     
     
         3 . The metal resistor structure of  claim 1 , wherein said metal nitride layer and said in-situ formed metal nitride layer provide a resistor having a graded nitrogen content. 
     
     
         4 . The metal resistor structure of  claim 1 , wherein said metal nitride layer and said in-situ formed metal nitride layer provide a resistor having greater than 60 atomic % nitrogen located therein. 
     
     
         5 . The metal resistor structure of  claim 1 , wherein said metal nitride layer and said in-situ formed metal nitride layer are components of a patterned resistor structure, and wherein another dielectric material layer is located on exposed portions of said nitrogen enriched dielectric surface layer and said patterned resistor structure, and further wherein said another dielectric material includes a plurality of conductive structures embedded therein. 
     
     
         6 . The metal resistor structure of  claim 5 , wherein a first conductive structure of said plurality of conductive structures is direct contact with one portion of said metal nitride layer, and wherein a second conductive structure of said plurality of conductive structures is direct contact with another portion of said metal nitride layer. 
     
     
         7 . The metal resistor structure of  claim 1 , wherein said nitrogen enriched dielectric surface layer extends from 0.5 nm to 20 nm into said dielectric material layer. 
     
     
         8 . The metal resistor of  claim 1 , wherein said metal nitride layer is selected from the group consisting of TaN, TiN, RuN, CoN, WN and TaRuN. 
     
     
         9 . The metal resistor of  claim 1 , wherein said metal nitride layer includes less than 50 atomic % nitrogen. 
     
     
         10 . The metal resistor of  claim 1 , further comprising another dielectric material layer located beneath said dielectric material layer having said nitrogen enriched dielectric surface layer, wherein said another dielectric material layer comprises at least one conductive material embedded therein. 
     
     
         11 . The metal resistor of  claim 10 , wherein said at least one conductive material has an upper surface that is coplanar with an upper surface of said another dielectric material layer. 
     
     
         12 . The metal resistor of  claim 11 , further comprising a dielectric capping layer located between said another dielectric material layer and said dielectric material layer. 
     
     
         13 . The metal resistor of  claim 12 , wherein said dielectric capping layer is selected from the group consisting of SiC, Si 4 NH 3 , SiO 2 , a carbon doped oxide, and a nitrogen doped silicon carbide. 
     
     
         14 . A semiconductor structure comprising:
 a first dielectric material layer having at least one conductive material embedded therein;   a first dielectric capping layer located on an upper surface of said first dielectric material layer and partially on an upper surface of said at least one conductive material;   a metal resistor structure located on a portion of an upper surface of said first dielectric capping layer, said metal resistor comprising:
 a second dielectric material layer having a nitrogen enriched dielectric surface layer located in an upper region thereof; and 
 a metal nitride layer located atop said nitrogen enriched dielectric surface layer, wherein said metal nitride layer is separated from said nitrogen enriched dielectric surface layer of said dielectric material layer by an in-situ formed metal nitride layer; and 
   a second dielectric capping layer located on an upper surface of said a metal nitride layer.   
     
     
         15 . The semiconductor structure of  claim 14 , wherein said second dielectric capping layer has outer edges that are not vertically coincident to outer edges of said metal nitride layer and said in-situ formed metal nitride layer. 
     
     
         16 . The semiconductor structure of  claim 15 , further comprising a third dielectric layer located atop and surrounding said metal resistor structure. 
     
     
         17 . The semiconductor structure of  claim 16 , wherein said third dielectric layer includes a first metal structure contacting a surface of said at least one conductive material in said first dielectric material layer, and a second metal structure contacting a portion of said metal nitride layer of said metal resistor structure.