Semiconductor device and method for fabricating the same

Abstract

A method for fabricating a semiconductor device includes the steps of: forming a first metal interconnection on a substrate; forming a stop layer on the first metal interconnection; removing the stop layer to form a first opening; forming an electromigration enhancing layer in the first opening; and forming a second metal interconnection on the electromigration enhancing layer. Preferably, top surfaces of the electromigration enhancing layer and the stop layer are coplanar.

What is claimed is: 
     
         1 . A method for fabricating a semiconductor device, comprising:
 forming a first metal interconnection on a substrate;   forming a stop layer on the first metal interconnection;   removing the stop layer to form a first opening;   forming an electromigration enhancing layer in the first opening; and   forming a second metal interconnection on the electromigration enhancing layer.   
     
     
         2 . The method of  claim 1 , further comprising:
 forming a first inter-metal dielectric (IMD) layer on the substrate;   forming the first metal interconnection in the first IMD layer;   forming the stop layer on the first IMD layer;   forming the electromigration enhancing layer in the first opening;   forming a second IMD layer on the stop layer and the electromigration enhancing layer;   forming the second metal interconnection on the electromigration enhancing layer; and   forming a first magnetic tunneling junction (MTJ) on the second metal interconnection.   
     
     
         3 . The method of  claim 2 , further comprising planarizing the electromigration enhancing layer before forming the second IMD layer. 
     
     
         4 . The method of  claim 2 , further comprising:
 forming the second metal interconnection and a third metal interconnection on the electromigration enhancing layer; and   forming the first MTJ on the second metal interconnection and a second MTJ on the third metal interconnection.   
     
     
         5 . The method of  claim 4 , further comprising:
 removing the stop layer to form the first opening and a second opening;   forming the electromigration enhancing layer in the first opening and the second opening;   planarizing the electromigration enhancing layer to form a first electromigration enhancing layer and a second electromigration enhancing layer; and   forming the second metal interconnection on the first electromigration enhancing layer and the third metal interconnection on the second electromigration enhancing layer.   
     
     
         6 . The method of  claim 1 , wherein the first metal interconnection and the second metal interconnection comprise different materials. 
     
     
         7 . The method of  claim 1 , wherein the first metal interconnection and the electromigration enhancing layer comprise different materials. 
     
     
         8 . The method of  claim 1 , wherein the second metal interconnection and the electromigration enhancing layer comprise different materials.