Structures to mechanically stabilize isolated top-level metal lines

Abstract

A method is described for providing protective structure to protect integrated circuits against various types of damages. The method includes patterning a signal line from a metal material as a terminal conductive layer of an integrated circuit die, patterning a first protective structure to surround the signal line, and patterning a second protective structure to surround the first protective structure.

What is claimed is:  
     
         1 . A method comprising: 
 patterning a signal line from a metal material as a terminal conductive layer of an integrated circuit die;    patterning a first protective structure to surround the signal line; and    patterning a second protective structure to surround the first protective structure.    
     
     
         2 . The method of  claim 1 , further comprising: 
 patterning the first protective structure as a continuous structure to enclose the signal line.    
     
     
         3 . The method of  claim 1 , further comprising: 
 patterning the first and second protective structures to one of a low rail supply line and a high rail supply line.    
     
     
         4 . A method comprising: 
 forming a first interconnection metallization layer on a substrate;    forming a second interconnection metallization layer on the first interconnection metallization layer;    forming at least one signal line coupled to the first interconnection metallization layer in the second interconnection metallization;    forming at least one protective structure that surrounds the at least one signal line in the second interconnection metallization layer.    
     
     
         5 . The method of  claim 4 , wherein the forming at least one protective structure that surrounds the at least one signal line comprises using a continuous loop-like shape protective structure to enclose the signal line.  
     
     
         6 . The method of  claim 4 , further comprising coupling the at least one protective structure to a low rail supply voltage.  
     
     
         7 . The method of  claim 4 , further comprising coupling the at least one protective structure to a high rail supply voltage.  
     
     
         8 . The method of  claim 4 , wherein the at least one protective structure is spaced from the signal line at approximately 2 microns.  
     
     
         9 . The method of  claim 4 , wherein the first interconnection metallization layer has a first volume and the second interconnection metallization layer has a second volume greater than the first volume.  
     
     
         10 . The method of  claim 4 , wherein the forming at least one protective structure comprises forming a plurality of protective structures (PSi) for i=1 . . . N, a first protective structure PSi surrounding the signal line, each protective structure PS1 surrounding a previous protective structure PSi-1.