Protection Layers for Conductive Pads and Methods of Formation Thereof

Abstract

In one embodiment, a method of forming a semiconductor device includes forming a metal line over a substrate and depositing an alloying material layer over a top surface of the metal line. The method further includes forming a protective layer by combining the alloying material layer with the metal line.

What is claimed is: 
     
         1 . A semiconductor device comprising:
 a metal line comprising metal atoms disposed over a substrate, a portion of a top surface of the metal line having a contact area; and   a protective layer comprising the metal atoms disposed on the contact area, the protective layer being a different material from the metal line.   
     
     
         2 . The device of  claim 1 , wherein the protective layer is disposed within a recess in the metal line. 
     
     
         3 . The device of  claim 1 , wherein the protective layer is disposed on sidewalls of the metal line. 
     
     
         4 . The device of  claim 1 , wherein the metal atoms comprise copper. 
     
     
         5 . The device of  claim 4 , wherein the protective layer further comprises aluminum. 
     
     
         6 . The device of  claim 4 , wherein the protective layer comprises a material selected from the group consisting of tin, magnesium, chromium, nickel, and zinc. 
     
     
         7 . The device of  claim 1 , wherein the metal line is the uppermost metal line over the substrate. 
     
     
         8 . The device of  claim 1 , wherein the protective layer comprises an alloy layer disposed on the metal line and an oxide layer disposed over the alloy layer, wherein the alloy layer comprises copper and an alloying element and the oxide layer comprises an oxide of the alloying element. 
     
     
         9 . The device of  claim 1 , wherein the metal atoms comprise copper, and wherein the protective layer comprises a layer of aluminum bronze disposed on the metal line and a layer of alumina disposed on the layer of aluminum bronze. 
     
     
         10 . A semiconductor device comprising:
 a first metal line comprising metal atoms disposed over a device region of a substrate, a portion of a top surface of the metal line having a contact area;   a first protective layer comprising the metal atoms disposed on the contact area, the first protective layer being a different material from the first metal line;   a second metal line forming part of a protective structure, the protective structure surrounding the device region of the substrate; and   a second protective layer disposed over and contacting the second metal line.   
     
     
         11 . The device of  claim 10 , wherein the first protective layer is disposed within a recess in the metal line. 
     
     
         12 . The device of  claim 10 , wherein the first protective layer is disposed on sidewalls of the first metal line, and wherein the second protective layer is disposed on sidewalls of the second metal line. 
     
     
         13 . The device of  claim 10 , wherein the metal atoms comprise copper. 
     
     
         14 . The device of  claim 10 , wherein the second protective layer comprises the metal atoms. 
     
     
         15 . The device of  claim 14 , wherein the metal atoms comprise copper. 
     
     
         16 . The device of  claim 15 , wherein the first and the second protective layers further comprise aluminum. 
     
     
         17 . The device of  claim 10 , wherein the protective structure is a moisture barrier.