Conductor-dielectric structure and method for fabricating

Abstract

A conductor-dielectric interconnect structure is fabricated by providing a structure comprising a dielectric layer having a patterned feature therein; depositing a plating seed layer on the dielectric layer in the patterned feature; depositing a sacrificial seed layer on the plating seed layer in the via; reducing the thickness of the sacrificial seed layer by reverse plating; and plating a conductive metal on the sacrificial seed layer in the patterned feature. Also provided is a dielectric layer having a via therein; a plating seed layer on the dielectric layer in the patterned feature; and a discontinuous sacrificial seed layer located in the patterned feature.

1 . A method for fabricating a conductor-dielectric interconnect structure which comprises providing a structure comprising a dielectric layer having a patterned feature therein; depositing a plating seed layer on the dielectric layer in said patterned feature; depositing a sacrificial seed layer on said plating seed layer in said patterned feature; reducing the thickness of the sacrificial seed layer by reverse plating; and depositing a conductive material on the sacrificial seed layer in said patterned feature.  
   
   
       2 . The method of  claim 1  wherein the structural includes a single or dual damascene structure or both.  
   
   
       3 . The method of  claim 1  wherein the plating seed layer comprises Ru or Ir or both.  
   
   
       4 . The method of  claim 1  wherein the sacrificial seed layer comprises Cu or a Cu alloy.  
   
   
       5 . The method of  claim 1  wherein the plating seed layer comprise Ru and Ta and/or TaN; Ir and Ta and/or TaN; Ru and TiSiN; and Ir and TiSiN.  
   
   
       6 . The method of  claim 1  wherein the sacrificial seed layer is about 3 nm to about 100 nm thick.  
   
   
       7 . The method of  claim 1  wherein the thickness of the sacrificial seed layer is reduced to at least 50% of the original thickness.  
   
   
       8 . The method of  claim 1  wherein the thickness of the sacrificial seed layer is reduced to provide a discontinuous sacrificial seed layer.  
   
   
       9 . The method of  claim 1  wherein the conductive material is selected from the group consisting of Cu, Al, Ag, Au, W and alloys thereof.  
   
   
       10 . The method of  claim 1  wherein said conductive material comprises Cu or Cu alloy.  
   
   
       11 . The method of  claim 1  which further comprises planarizing the conductive material.  
   
   
       12 . The method of  claim 1  wherein the plating seed layer is deposited by chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques.  
   
   
       13 . The method of  claim 1  wherein the sacrificial seed layer is deposited by physical vapor deposition (PVD) or chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques.  
   
   
       14 . The method of  claim 13  wherein the sacrificial seed layer is deposited in the same platform where the plating seed was deposited.  
   
   
       15 . The method of  claim 1  wherein conductive material is deposited by electroless or electroplating and is carried out in the same plating bath in which the sacrificial layer is thinned.  
   
   
       16 . The method of  claim 1  wherein the structure further comprises a capping layer located above the dielectric layer and barrier layer.  
   
   
       17 . A structure which comprises a dielectric layer having a patterned feature therein; a plating seed layer on the dielectric layer in said patterned feature; and a discontinuous sacrificial seed layer located in said patterned feature on said plating seed layer.  
   
   
       18 . The structure of  claim 17  wherein the plating seed layer comprises Ru or Ir or both.  
   
   
       19 . The structure of  claim 17  wherein the sacrificial seed layer comprises Cu or Cu alloy.  
   
   
       20 . The structure of  claim 17  which further comprises a conductive interconnect on the sacrificial seed layer.