Ball Limiting Metallurgy, Interconnection Structure Including the Same, and Method of Forming an Interconnection Structure

Abstract

A ball-limiting metallurgy includes a substrate, a barrier layer formed over the substrate, an adhesion layer formed over the barrier layer, a first solderable layer formed over the adhesion layer, a diffusion barrier layer formed over the adhesion layer, and a second solderable layer formed over the diffusion barrier layer.

1 . A ball-limiting metallurgy, comprising: 
 a substrate; a barrier layer formed over the substrate;    an adhesion layer formed over the barrier layer;    a first solderable layer formed over the adhesion layer;    a diffusion barrier layer formed over the adhesion layer; and    a second solderable layer formed over the diffusion barrier layer.    
   
   
       2 . The ball-limiting metallurgy of  claim 1 , wherein the first solderable layer is made of copper.  
   
   
       3 . The ball-limiting metallurgy of  claim 2 , wherein the diffusion barrier layer is made of CoWP.  
   
   
       4 . The ball-limiting metallurgy of  claim 1 , wherein the second solderable layer is made of Ni.  
   
   
       5 . The ball-limiting metallurgy of  claim 1 , wherein the barrier layer, the adhesion layer, the first solderable layer, the diffusion barrier layer, and the second solderable layer are surrounded by a polyimide layer.  
   
   
       6 . An interconnection structure for flip-chip attachment of microelectronic device chips to packages, comprising: 
 a ball-limiting metallurgy comprising:    a barrier layer formed over the microelectronic device chip;    an adhesion layer formed over the barrier layer;    a first solderable layer formed over the adhesion layer;    a diffusion barrier layer formed over the adhesion layer; and    a second solderable layer formed over the diffusion barrier layer; and    at least one lead-free solder ball formed over the second solderable layer.    
   
   
       7 . The interconnection structure of  claim 6 , wherein the first solderable layer is made of copper.  
   
   
       8 . The interconnection structure of  claim 7 , wherein the diffusion barrier layer is made of CoWP.  
   
   
       9 . The interconnection structure of  claim 6 , wherein the second solderable layer is made of Ni.  
   
   
       10 . The interconnection structure of  claim 6 , wherein the barrier layer, the adhesion layer, the first solderable layer, the diffusion barrier layer, and the second solderable layer are surrounded by a polyimide layer.  
   
   
       11 . The interconnection structure of  claim 6 , wherein the at least one lead-free solder ball is made of a tin alloy.