Surface repair structure and process for interconnect applications

Abstract

Semiconductor interconnect structures including a surface-repair material, e.g., a noble metal or noble metal alloy, that fills hollow-metal related defects located within a conductive material are provided. The filling of the hollow-metal related defects with the surface repair material improves the electromigration (EM) reliability of the structure as well as decreasing in-line defect related yield loss.

1 . An interconnect structure comprising:
 a dielectric material having a dielectric constant of about 4.0 or less and at least one conductive material embedded therein, the at least one conductive material having an upper surface that is coplanar with an upper surface of the dielectric material and the upper surface of the at least one conductive material has hollow-metal related defects located therein; and   a surface repair material located within and filling the hollow-metal related defects that are present at the upper surface of the at least one conductive material.   
     
     
         2 . The interconnect structure of  claim 1  wherein said at least one conductive material comprises polySi, a conductive metal, a conductive metal alloy, a conductive metal silicide or combinations and multilayers thereof. 
     
     
         3 . The interconnect structure of  claim 2  wherein said at least one conductive material is a conductive metal selected from one of Cu, W and Al. 
     
     
         4 . The interconnect structure of  claim 1  wherein said dielectric material comprises silicon, dioxide, a silsesquioxane, a C doped oxide that includes at least atoms of Si, C, O and H, a thermosetting polyarylene ether, or multilayers thereof. 
     
     
         5 . The interconnect structure of  claim 1  wherein said at least one conductive material is located within a line opening, a via opening, a combined line opening and via opening or any combination thereof. 
     
     
         6 . The interconnect structure of  claim 1  wherein said surface repair material comprises a noble metal or an alloy of a noble metal. 
     
     
         7 . The interconnect structure of  claim 6  wherein said surface repair material is one of Ru, Co, Pt, W, Rh, Ir and Co(W, P, B). 
     
     
         8 . An interconnect structure comprising:
 a dielectric material having a dielectric constant of about 4.0 or less and at least one conductive material embedded therein, the at least one conductive material having an upper surface that is coplanar with an upper surface of the dielectric material and the upper surface of the at least one conductive material has hollow-metal related defects located therein;   a surface repair material located within and filling the hollow-metal related defects that are present at the upper surface of the at least one conductive material; and   a dielectric capping layer located on the upper surface of the at least one conductive material, an upper surface of the surface repair material, and the upper surface of the dielectric material.   
     
     
         9 . The interconnect structure of  claim 8  wherein said surface repair material comprises a noble metal or an alloy of a noble metal. 
     
     
         10 . The interconnect structure of  claim 9  wherein said surface repair material is one of Ru, Co, Pt, W, Rh, Ir and Co(W, P, B). 
     
     
         11 . The interconnect structure of  claim 8  wherein said dielectric capping layer comprises SiC, Si 4 NH 3 , SiO 2 , a carbon doped oxide, a nitrogen and hydrogen doped silicon carbide SiC(N,H) or multilayers thereof. 
     
     
         12 . An interconnect structure comprising:
 a dielectric material having a dielectric constant of about 4.0 or less and at least one conductive material embedded therein, the at least one conductive material having an upper surface that is coplanar with an upper surface of the dielectric material and the upper surface of the at least one conductive material has hollow-metal related defects located therein;   a surface repair material located within and filling the hollow-metal related defects that are present at the upper surface of the at least one conductive material;   a noble metal cap located on the upper surface of said at least one conductive material, said noble metal cap does not extend onto the upper surface of the dielectric material; and   a dielectric capping layer located on the upper surface of the dielectric material as well as atop the noble metal cap.   
     
     
         13 . The interconnect structure of  claim 12  wherein said surface repair material comprises a noble metal or an alloy of a noble metal. 
     
     
         14 . The interconnect structure of  claim 13  wherein said surface repair material is one of Ru, Co, Pt, W, Rh, Ir and Co(W, P, B). 
     
     
         15 . The interconnect structure of  claim 12  wherein said dielectric capping layer comprises SiC, Si 4 NH 3 , SiO 2 , a carbon doped oxide, a nitrogen and hydrogen doped silicon carbide SiC(N,H) or multilayers thereof. 
     
     
         16 . The interconnect structure of  claim 12  wherein said noble metal cap is selected from the group consisting of Ru, Ir, Rh, Pt, Co, W and alloys thereof. 
     
     
         17 . A method of fabricating an interconnect structure comprising:
 providing a dielectric material having a dielectric constant of about 4.0 or less and at least one conductive material embedded therein, the at least one conductive material has an upper surface that is coplanar with an upper surface of the dielectric material and the upper surface of the at least one conductive material has hollow-metal related defects that extend inward into the at least one conductive material; and   filling said hollow-meal related defects with a surface repair material.   
     
     
         18 . The method of  claim 17  wherein said filling the hollow-metal related defects with the surface repair material includes selecting one of Ru, Co, Rh, Pt, W, Ir and Co(W, P, B). 
     
     
         19 . The method of  claim 17  wherein said filling the hollow-metal defects is selected from the group consisting of chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), and atomic layer deposition (ALD), said depositions are performed at a temperature of 200° C. or less. 
     
     
         20 . The method of  claim 17  wherein said filling the hollow-metal related defects includes electroless plating or electroplating. 
     
     
         21 . The method of  claim 17  wherein said hollow-metal defects are formed by one of patterning, metalizing, planarizing and etching. 
     
     
         22 . The method of  claim 17  further comprising forming a dielectric capping layer on the upper surface of the at least one conductive material, an upper surface of the surface repair material and the upper surface of the dielectric material. 
     
     
         23 . The method of  claim 17  further comprising forming a noble metal cap on the upper surface of said at least one conductive material, said noble metal cap does not extend onto the upper surface of the dielectric material. 
     
     
         24 . The method of  claim 23  further comprising forming a dielectric capping layer on the upper surface of the dielectric material as well as atop the noble metal cap. 
     
     
         25 . The method of  claim 17  wherein said at least one conductive material is located within a line opening, a via opening, a combined line opening and via opening or any combination thereof.