Electroplating and electroless plating of conductive materials into openings, and structures obtained thereby

Abstract

A through hole ( 114 ) is formed in a wafer ( 104 ) comprising a semiconductor substrate ( 110 ). A seed layer ( 610 ) is sputtered on the bottom surface of the wafer. The seed is not deposited over the through hole's sidewalls adjacent the top surface of the wafer. A conductor ( 810 ) is electroplated into the through hole. In another embodiment, a seed is deposited into an opening in a wafer through a dry film resist mask ( 1110 ). The dry film resist overhangs the edges of the opening, so the seed is not deposited over the opening's sidewalls adjacent the top surface of the wafer. In another embodiment, a dielectric ( 120 ) is formed in an opening in a semiconductor substrate ( 110 ) by a non-conformal physical vapor deposition (PVD) process that deposits the dielectric on the sidewalls but not the bottom of the opening. A seed ( 610 ) is formed on the bottom by electroless plating. A conductor ( 810 ) is electroplated on the seed. In another embodiment, a dielectric ( 2910 ) is formed in the opening to cover the entire surface of the opening. A non-conformal layer ( 120 ) is deposited by PVD over the sidewalls but not the bottom of the opening. The dielectric ( 2910 ) is etched off the bottom with the non-conformal layer ( 120 ) as a mask. A seed ( 610 ) is formed on the bottom by electroless plating. The non-conformal layer can be formed by electroplating. It can be tantalum deposited by electroplating, then anodized. Other embodiments are also provided.

1 . a manufacturing method comprising: 
 forming an opening in a first surface of a body comprising a semiconductor substrate, wherein the opening extends into the semiconductor substrate, and forming a seed for electroplating a conductor into the opening; and    electroplating the conductor into the opening, wherein the electroplating is initiated on the seed at a distance from the first surface of the body but not over the opening's sidewalls adjacent the first surface of the body;    wherein either before or after the electroplating operation, a through hole is formed in the semiconductor substrate at the location of the opening.    
   
   
       2 . The method of  claim 1  wherein forming the opening comprises extending the opening into a first surface of the semiconductor substrate, and the electroplating is initiated at a distance from the first surface of the semiconductor substrate but not over the opening's sidewalls adjacent the first surface of the semiconductor substrate.  
   
   
       3 . The method of  claim 1  wherein the seed is spaced from the first surface of the body.  
   
   
       4 - 11 . (canceled)  
   
   
       12 . The method of  claim 1  further comprising forming a conductive layer over a second surface of the body; 
 wherein forming the opening and the through hole comprises: 
 forming the opening in the first surface of the body such that the opening does not go through the body;  
 after forming the conductive layer, extending the opening to form the through hole and expose the conductive layer from the first surface of the body;  
   wherein the seed electrically contacts the conductive layer in the opening;    wherein the method further comprises coupling the conductive layer to an electrical potential for the electroplating operation, wherein during the electroplating operation the seed is coupled to the electrical potential through the conductive layer.    
   
   
       13 - 34 . (canceled)  
   
   
       35 . A structure comprising: 
 a body comprising semiconductor material;    an opening in the body;    a first conductive layer over a sidewall of the opening;    an electrophoretic photoresist over the first conductive layer in the opening; and    a second conductive layer in the opening, wherein at least a portion of the second conductive layer is separated from the first conductive layer by the photoresist.    
   
   
       36 . The structure of  claim 35  wherein another portion of the second conductive layer meets the first conductive layer.  
   
   
       37 . The structure of  claim 35  wherein the body comprises a semiconductor substrate, and the opening and the second conductive layer go through the semiconductor substrate.  
   
   
       38 . The structure of  claim 35  wherein the body is an integrated circuit, and the second conductive layer is an interconnect element of the integrated circuit.  
   
   
       39 - 88 . (canceled)  
   
   
       89 . A structure comprising: 
 a body comprising semiconductor material;    an opening in the body;    a first dielectric layer over a sidewall of the opening;    a first conductive layer over the first dielectric layer;    a second dielectric layer over the first conductive layer over the sidewall of the opening, wherein the second dielectric layer does not completely cover the first conductive layer in the opening;    a second conductive layer over the second dielectric layer and the first conductive layer, wherein the second conductive layer physically contacts a portion of the first conductive layer in the opening but the second conductive layer is separated by the second dielectric layer from another portion of the first conductive layer over the sidewall of the opening.    
   
   
       90 . The structure of  claim 89  wherein the opening passes through the body.  
   
   
       91 . The structure of  claim 89  wherein the second dielectric layer comprises an oxide of a metal, and said metal is present in a non-oxidized state between the second dielectric layer and the first conductive layer.