Contact surrounded by passivation and polymide and method therefor

Abstract

A semiconductor device has contact between the last interconnect layer and the bond pad that includes a barrier metal between the bond pad and the last interconnect layer. Both a passivation layer and a polyimide layer separate the last interconnect layer and the bond pad. The passivation layer is patterned to form a first opening to contact the last interconnect layer. The polyimide layer is also patterned to leave a second opening that is inside and thus smaller than the first opening through the passivation. The barrier layer is then deposited in contact with the last interconnect layer and bounded by the polyimide layer. The bond pad is then formed in contact with the barrier, and a wire bond is then made to the bond pad.

1 - 7 . (canceled) 
     
     
         8 . A method of making semiconductor device, comprising:
 providing an active circuitry region;   providing a contact region;   forming a last interconnect layer over the active circuitry and the contact region;   depositing a passivation layer over the last interconnect layer;   etching a first opening in the passivation layer, wherein the first opening is bounded be a sidewall of the passivation layer;   depositing a polyimide layer over the passivation layer;   etching a second opening in the polyimide layer, wherein the second opening is within the first opening so that the polyimide layer separates the second opening from the sidewall of the passivation layer;   depositing a barrier metal layer over the polyimide layer and contacting the last interconnect layer in the second opening; and   depositing a bond pad metal over the barrier metal.   
     
     
         9 . The method of  claim 8  further comprising forming a wire bond on the bond pad metal over the active circuitry region. 
     
     
         10 . The method of  claim 9 , wherein:
 the step of depositing the barrier metal layer is further characterized by the barrier metal layer comprising titanium tungsten;   the step of depositing the bond pad metal is further characterized by the bond pad metal comprising gold, and   the step of depositing last interconnect layer is further characterized by the last interconnect layer comprising aluminum.   
     
     
         11 . The method of  claim 8 , wherein the step of depositing the polyimide layer is further characterized by the polyimide layer comprising photo-imageable polyimide. 
     
     
         12 . The method of  claim 11 , wherein:
 the step of depositing the passivation layer is further characterized by the passivation layer comprising nitride;   the step of depositing the barrier metal layer is further characterized by the barrier metal layer comprising titanium tungsten;   the step of depositing the bond pad metal is further characterized by the bond pad metal comprising gold, and   the step of depositing last interconnect layer is further characterized by the last interconnect layer comprising aluminum.   
     
     
         13 . The method of  claim 8 , wherein;
 the step of depositing the passivation layer is further characterized by the passivation layer comprising nitride;   the step of depositing the barrier metal layer is further characterized by the barrier metal layer comprising titanium tungsten;   the step of depositing the bond pad metal is further characterized by the bond pad metal comprising gold, and   the step of depositing last interconnect layer is further characterized by the last interconnect layer comprising aluminum.   
     
     
         14 . The method of  claim 8 , wherein the step of etching the polyimide layer is further characterized by leaving at least a thickness of one micron of polyimide as measured from the sidewall of the passivation layer. 
     
     
         15 - 20 . (canceled)