Integrating a bottomless via to promote adsorption of antisuppressor on exposed copper surface and enhance electroplating superfill on noble metals

Abstract

A method for forming a copper interconnect is described. An opening in a dielectric layer disposed on a substrate is formed. A barrier layer is formed on the opening. A seed layer is formed on the barrier layer. The seed layer includes a noble metal copper alloy, the copper having less than 50% of the atomic weight of the noble metal copper alloy.

1 . An apparatus comprising:
 a dielectric layer having an opening;   a barrier layer on the opening; and   a seed layer on the barrier layer, the seed layer having a noble metal-copper alloy, the copper having less than 50% weight of the noble metal-copper alloy layer.   
   
   
       2 . The apparatus of  claim 1  wherein the seed layer further includes a reliability enhancing metal alloy species where the copper and the reliability enhancing metal alloy species having less than 50% weight of the noble metal-copper-reliability enhancing metal alloy. 
   
   
       3 . An apparatus comprising:
 a dielectric layer having an opening, the dielectric layer disposed on a copper interconnect of a substrate;   a barrier layer formed on the opening; and   a seed layer formed on the barrier layer, the seed layer having a noble metal or a noble metal-copper alloy, the bottom of the opening exposing copper from the copper interconnect.   
   
   
       4 . The apparatus of  claim 3  further comprising:
 a copper or copper alloy layer formed on the seed layer and filling the opening using an electroplating or electroless bath, the exposed copper at the bottom of the opening functioning as a seed layer for the electroplating or electroless in the opening.