Methods of forming through-silicon via structures including conductive protective layers

Abstract

Through-Silicon-Via (TSV) structures can be provided by forming a conductive via through a substrate extending from an upper surface of the substrate to a backside surface of the substrate, that is opposite the upper surface, and having a conductive protective layer comprising Ni and/or Co formed at a bottom of the conductive via. A polymer insulating layer can be formed on the backside surface that is separate from the substrate and in contact with the conductive protective layer.

1 . A method of forming a Through-Silicon-Via (TSV) comprising:
 forming a conductive via through a substrate extending from an upper surface of the substrate to a backside surface of the substrate, opposite the upper surface, having a conductive protective layer comprising Ni and/or Co formed at a bottom of the conductive via; and   forming a polymer insulating layer on the backside surface that is separate from the substrate and in contact with the conductive protective layer.   
     
     
         2 . A method according to  claim 1  wherein forming a conductive via further comprises:
 forming a recess in the substrate, the recess having an opening on the upper surface of the substrate; 
 forming the conductive protective layer at the bottom of the recess; 
 depositing a conductive material on the conductive protective layer in the recess; and 
 processing the backside of the substrate to provide a protruding portion of the conductive material and the conductive protective layer protruding from the backside surface. 
 
     
     
         3 . A method according to  claim 2  further comprising:
 forming a groove in an upper surface of the conductive material having an opening facing away from the substrate and configured to extend into the via to beneath the upper surface of the substrate. 
 
     
     
         4 . A method according to  claim 3  further comprising:
 forming solder in the groove; and 
 electrically connecting the solder to another TSV structure above the conductive via. 
 
     
     
         5 . A method according to  claim 2  further comprising:
 forming solder on a planar upper surface of the conductive material; and 
 electrically connecting the solder to another TSV structure above the conductive via. 
 
     
     
         6 . A method according to  claim 1  wherein the polymer insulating layer has a viscosity comprising about 290 cP, a resistivity of about 1010 ohm-cm, and a modulus of about 1 GPa to about 3 GPa. 
     
     
         7 . A method of forming a Through-Silicon-Via (TSV) comprising:
 forming a recess in a substrate having an opening on an upper surface of the substrate;   forming a conductive protective layer at a bottom of the recess;   depositing a conductive material on the conductive protective layer in the recess;   processing a backside surface of the substrate, opposite the upper surface, to provide a protruding portion of the conductive material and the conductive protective layer protruding from the backside surface; and   coating the protruding portion and the substrate with a polymer insulating layer to a thickness of about 1 to about 2 micrometers at a first location spaced apart from where the protruding portion protrudes from the backside surface and a thickness of about 8 micrometers at a second location at the protruding portion measured relative to the backside surface.   
     
     
         8 . A method according to  claim 7  wherein the conductive protective layer comprises Ni and/or Co. 
     
     
         9 . A method of forming a Through-Silicon-Via (TSV) comprising:
 forming a recess in a substrate having an opening on an upper surface of the substrate;   forming an insulator layer, a diffusion barrier layer, and a conductive protective layer comprising Ni and/or Co, at a bottom of the recess and on the upper surface;   forming a photo-resist pattern including an opening on the upper surface exposing the recess;   depositing a conductive material in the recess through the opening;   processing the upper surface to remove the photo-resist pattern and portions of the conductive protective layer and the diffusion barrier layer beneath the photo-resist pattern;   processing a backside surface of the substrate, opposite the upper surface, to provide a protruding portion of the conductive material and the conductive protective layer protruding from the backside surface;   coating the protruding portion with a polymer insulating layer that is separate from the substrate; and   removing a portion of the polymer insulating layer to expose the protruding portion.   
     
     
         10 . A method according to  claim 9  wherein processing further comprises:
 processing the backside surface using grinding or chemical-mechanical-polishing (CMP) to reduce a thickness of the substrate to provide a reduced backside surface and to avoid exposing the conductive protective layer; and then 
 dry-etching the reduced backside surface to further thin the substrate and to expose the conductive protective layer. 
 
     
     
         11 . A method of forming a Through-Silicon-Via (TSV) comprising:
 forming a recess in a substrate having an opening on an upper surface of the substrate;   forming an insulator layer, a conductive protective layer comprising Ni and/or Co, and a diffusion barrier layer at a bottom of the recess and on the upper surface;   forming a photo-resist pattern including an opening on the upper surface exposing a central portion of the bottom of the recess and covering an outer portion of the bottom of the recess;   processing the upper surface to remove a portion of the barrier layer in the opening to expose an underlying portion of the conductive protective layer;   depositing a conductive material in the recess through the opening;   processing a backside surface of the substrate, opposite the upper surface, to provide a protruding portion of the conductive material and the conductive protective layer protruding from the backside surface;   coating the protruding portion with a polymer insulating layer that is separate from the substrate; and   removing a portion of the polymer insulating layer to expose the protruding portion   
     
     
         12 . A method according to  claim 11  wherein processing further comprises:
 processing the backside surface using grinding or chemical-mechanical-polishing (CMP) to reduce a thickness of the substrate to provide a reduced backside surface and to avoid exposing the conductive protective layer; and then 
 dry-etching the reduced backside surface to further thin the substrate and to expose the conductive protective layer. 
 
     
     
         13 . A method of forming a Through-Silicon-Via (TSV) comprising:
 forming a recess in a substrate having an opening on an upper surface of the substrate;   forming an insulator layer, a diffusion barrier layer, and a conductive protective layer comprising Ni and/or Co, at a bottom of the recess and on the upper surface;   forming a photo-resist pattern in the recess and outside the recess so that a portion of the insulator layer, the diffusion barrier layer, and the conductive protective layer outside the recess is exposed;   etching the portion of the insulator layer, the diffusion barrier layer, and the conductive protective layer outside the recess to remove the portion;   removing the photo-resist pattern;   depositing a conductive material in the recess;   processing a backside surface of the substrate, opposite the upper surface, to provide a protruding portion of the conductive material and the conductive protective layer protruding from the backside surface;   coating the protruding portion with a polymer insulating layer that is separate from the substrate; and   removing a portion of the polymer insulating layer to expose the protruding portion.   
     
     
         14 . A method according to  claim 9  wherein processing further comprises:
 processing the backside surface using grinding or chemical-mechanical-polishing (CMP) to reduce a thickness of the substrate to provide a reduced backside surface and to avoid exposing the conductive protective layer; and then 
 dry-etching the reduced backside surface to further thin the substrate and to expose the conductive protective layer.