Metal bond pad for integrated circuits allowing improved probing ability of small pads

Abstract

The present invention is a metal bond pad that provides electrical and mechanical connection to an integrated circuit (IC). The metal bond pad is configured to accommodate for probe travel during probing measurements, without modifying the size of the passivation opening of the bond pad. This enables higher density of active devices on the IC and therefore increases integration and lowers IC cost. The metal bond pad for the integrated circuit includes a substrate, a first metal layer, and a second metal layer. The substrate has the first metal layer disposed therein, having an opening from the top surface of the substrate. The second metal layer has a first-end portion, a second-end portion and a center portion disposed between the first-end portion and the second-end portion. The center portion of the second metal layer is aligned with the opening in the substrate and a bottom surface of the center portion is in contact with the top surface of the first metal layer. A top surface of the center portion has a recessed region that forms a first edge with said first-end portion and a second edge with said second-end portion. The first-end portion of the second metal layer is disposed on the top surface of the substrate and extends from the first edge of the recessed region. It has a length defined from the first edge of the opening. The second-end portion is also disposed on the top surface of the substrate and extends from the second edge of the recessed region. It has a length defined from the second edge of the recessed region, and it is longer than the length of the first-portion.

1 - 16 . (canceled)  
   
   
       17 . A bond pad for an integrated circuit, comprising: 
 a substrate; and    a first metal layer and a second metal layer disposed on said substrate;    said second metal layer having a first-end portion, a second-end portion, and a center portion disposed between said first-end portion and said second-end portion, said second metal layer having a recessed region that separates said first-end portion from said second-end portion, a bottom surface of said center portion in direct contact with a top surface of said first metal layer;    said first-end portion and said second-end portion are disposed on a top surface of said substrate and having respective lengths that are defined from corresponding edges of said recessed region, wherein said length of said second end portion is longer than said length of said first end portion.    
   
   
       18 . The bond pad of  claim 17 , wherein said length of said second-end portion is determined to accommodate travel of a probe when said probe is applied to a top surface of said center portion of said second metal layer.  
   
   
       19 . The bond pad of  claim 18 , wherein said travel is responsive to a force applied to one end of said probe.  
   
   
       20 . The bond pad of  claim 17 , wherein said first metal layer is aluminum and said second metal layer is copper.  
   
   
       21 . The bond pad of  claim 17 , wherein said center portion is recessed relative to said first-end portion and said second-end portion.  
   
   
       22 . The bond pad of  claim 17 , wherein a length of said first metal layer is a fixed offset relative to a length of said center portion.  
   
   
       23 . The bond pad of  claim 17 , wherein said first metal layer and said second metal layer are made of a common metal.  
   
   
       24 . The bond pad of  claim 23 , wherein said common metal is Aluminum (Al).  
   
   
       25 . The bond pad of  claim 23 , wherein said common metal is Copper (Cu).  
   
   
       26 . The bond pad of  claim 17 , wherein said first metal layer and said second metal layer are made of a common alloy.  
   
   
       27 . The bond pad of  claim 26 , wherein said common alloy is aluminum-copper (AlCu).  
   
   
       28 . The bond pad of  claim 17 , wherein said first metal layer and said second metal layer are made of different metals.  
   
   
       29 . The bond pad of  claim 17 , wherein said first metal layer and said second metal layer are made of different alloys.  
   
   
       30 . A method of manufacturing bond pads, comprising the steps of: 
 depositing a first metal layer on a substrate; and    depositing a second metal layer, of larger width than said first metal layer, so that a center portion is in direct contact with said first metal layer and a first-end portion of said second metal layer is longer than a second-end portion of said second metal layer.    
   
   
       31 . The method of  claim 30 , wherein said first metal layer is aluminum and said second metal layer is copper.