Selective metal deposition for electrochemical plating

Abstract

A method and apparatus for plating metal onto a substrate including positioning an anode spacer including a anode surface and a substrate contact surface with the substrate contact surface immediate a deposition surface of a substrate. The apparatus generally includes a plating cell configured to contain a plating solution therein, an anode disposed in the plating solution, and an anode spacer positioned in the plating cell, the anode spacer having an anode surface, and a substrate contact surface positioned immediate a deposition surface of the substrate, the anode spacer configured to communicated the plating solution therethrough. The method generally includes positioning a substrate in a plating cell, positioning an anode spacer immediate a deposition surface of the substrate, and flowing a plating solution through the anode spacer to plate a metal onto the deposition surface.

What is claimed is:  
     
         1 . An apparatus for plating metal on a substrate, comprising: 
 a plating cell configured to contain a plating solution therein;    an anode disposed in the plating solution; and    an anode spacer positioned in the plating cell, the anode spacer comprising: 
 an anode surface; and  
 a substrate contact surface positioned immediate a deposition surface of the substrate, the anode spacer configured to communicate the plating solution therethrough.  
   
     
     
         2 . The apparatus of  claim 1 , wherein the anode spacer is substantially rigid.  
     
     
         3 . The apparatus of  claim 1 , wherein the anode spacer has a periphery substantially equivalent to a periphery of the substrate.  
     
     
         4 . The apparatus of  claim 1 , wherein the substrate contact surface is positioned a distance from the substrate deposition surface equal to the thickness of the metal to be plated on the deposition surface.  
     
     
         5 . The apparatus of  claim 1 , wherein an electrical current passes through a plurality of conductive pores formed into the anode spacer.  
     
     
         6 . The apparatus of  claim 1 , wherein an electrical current passes through a plurality of conductive pores formed in the anode spacer and the plurality of conductive pore have an electrical resistance lower than an electrical resistance of the plating solution.  
     
     
         7 . The apparatus of  claim 1 , wherein a plurality of pores disposed in the anode spacer interconnect the anode surface and the substrate contact surface.  
     
     
         8 . The apparatus of  claim 7 , wherein each of the plurality of pores are of equal longitudinal length.  
     
     
         9 . The apparatus of  claim 7 , wherein each of the plurality of pores are of equal diameter.  
     
     
         10 . The apparatus of  claim 7 , wherein the plurality of pores are lined with a conductive material.  
     
     
         11 . The apparatus of  claim 7 , wherein the plurality of pores are lined with at least one of gold, platinum, and graphite.  
     
     
         12 . The apparatus of  claim 7 , wherein the plurality of pores are lined with a conductive material extending past the substrate contact surface.  
     
     
         13 . The apparatus of  claim 12 , wherein the plurality of pores have an adjustable length.  
     
     
         14 . The apparatus of  claim 12 , wherein each of the plurality of pores are lined with graphite extending past the substrate contact surface an equal longitudinal distance.  
     
     
         15 . The apparatus of  claim 1 , wherein the anode spacer comprises a plurality of anode spacers.  
     
     
         16 . The apparatus of  claim 1 , wherein the anode spacer further comprises a plurality of spacers extending from the anode toward the deposition surface.  
     
     
         17 . The apparatus of  claim 16 , wherein the plurality of spacers are composed of a conductive material.  
     
     
         18 . The apparatus of  claim 16 , wherein the plurality of spacers are composed of a conductive material selected from the group essentially comprising gold, platinum, and graphite.  
     
     
         19 . A method for plating a metal layer on a substrate, comprising: 
 positioning a substrate in a plating cell;    positioning an anode spacer immediate a deposition surface of the substrate;    and    flowing a plating solution through the anode spacer to plate a metal onto the deposition surface.    
     
     
         20 . The method of  claim 19 , further comprising rotating the anode spacer in relation to the deposition surface.  
     
     
         21 . The method of  claim 19 , wherein flowing a plating solution through the anode spacer comprises flowing the plating solution through a plurality of pores extending through the anode spacer.  
     
     
         22 . The method of  claim 19 , wherein flowing a plating solution through the anode spacer comprises flowing the plating solution through a plurality of pores extending through the anode spacer lined with a conductive material.  
     
     
         23 . The method of  claim 19 , wherein flowing a plating solution through the anode spacer comprises flowing the plating solution through a plurality of pores extending through the anode spacer lined with a conductive material selected from the group essentially comprising gold, platinum, and graphite.  
     
     
         24 . The method of  claim 19 , further comprising generating an electrical bias between an anode and the substrate.  
     
     
         25 . The method of  claim 19 , further comprising generating an electrical current to pass from an anode to the substrate through a plurality of conductive pores in the anode spacer.  
     
     
         26 . The method of  claim 19 , wherein the metal is copper.  
     
     
         27 . The method of  claim 19 , wherein positioning the anode spacer comprises positioning a plurality of anode spacers.  
     
     
         28 . The method of  claim 19 , wherein positioning the anode spacer comprises positioning a plurality of anode spacers in contact with the anode extending toward the deposition surface.  
     
     
         29 . The method of  claim 28 , wherein the plurality of spacers are composed of a conductive material.  
     
     
         30 . The method of  claim 28 , wherein the plurality of spacers are composed of gold, platinum, or graphite, or a combination thereof.  
     
     
         31 . An apparatus for controlling metal deposition on a substrate, comprising an anode spacer, wherein the anode spacer has a periphery substantially equivalent to the periphery of the substrate, the anode spacer is configured to communicate a plating solution therethrough, and the anode spacer includes an anode surface and a substrate contact surface positioned immediate a deposition surface of the substrate.  
     
     
         32 . The apparatus of  claim 31 , wherein the anode spacer is substantially rigid.  
     
     
         33 . The apparatus of  claim 31 , wherein a plurality of pores interconnect the anode surface and the substrate contact surface.  
     
     
         34 . The apparatus of  claim 33 , wherein each of the plurality of pores are of equal longitudinal length.  
     
     
         35 . The apparatus of  claim 33 , wherein each of the plurality of pores are of equal diameter.  
     
     
         36 . The apparatus of  claim 33 , wherein the plurality of pores are lined with a conductive material.  
     
     
         37 . The apparatus of  claim 33 , wherein the plurality of pores are lined with gold, platinum, or graphite, or a combination thereof.  
     
     
         38 . The apparatus of  claim 33 , wherein the plurality of pores are lined with a conductive material extending beyond the substrate contact surface.  
     
     
         39 . The apparatus of  claim 38 , wherein the plurality of pores have an adjustable length.  
     
     
         40 . The apparatus of  claim 33 , wherein each of the plurality of pores are lined with graphite extending past the substrate contact surface an equal longitudinal distance.  
     
     
         41 . The apparatus of  claim 31 , wherein the anode spacer comprises a plurality of anode spacers.  
     
     
         42 . The apparatus of  claim 31 , wherein the anode spacer further comprises a plurality of cylindrical spacers of equal longitudinal length and diameter.  
     
     
         43 . The apparatus of  claim 42 , wherein the plurality of spacers are composed of a conductive material.  
     
     
         44 . The apparatus of  claim 42 , wherein the plurality of spacers are composed of a conductive material selected from the group essentially comprising gold, platinum, and graphite.  
     
     
         45 . An apparatus for plating metal on a substrate, comprising: 
 a plating cell configured to contain a plating solution therein;    an anode disposed in the plating solution; and    an anode spacer positioned in the plating cell, the anode spacer comprising: 
 an anode surface;  
 a substrate contact surface positioned a distance from a deposition surface of the substrate sufficient to uniformly plate a metal to a desired thickness; and  
 a plurality of pores to communicate the plating solution to the deposition surface having an electrical resistance higher than the electrical resistance of the plating solution.  
   
     
     
         46 . The apparatus of  claim 45 , wherein the anode spacer is substantially rigid.  
     
     
         47 . The apparatus of  claim 45 , wherein the anode spacer has a periphery substantially equivalent to a periphery of the substrate.  
     
     
         48 . The apparatus of  claim 45 , wherein the plurality of pores are of equal longitudinal length.  
     
     
         49 . The apparatus of  claim 45 , wherein each of the plurality of pores are of equal diameter.  
     
     
         50 . The apparatus of  claim 45 , wherein the plurality of pores are lined with a conductive material.  
     
     
         51 . The apparatus of  claim 45 , wherein the plurality of pores are lined with at least one of gold, platinum, and graphite.  
     
     
         52 . The apparatus of  claim 45 , wherein the plurality of pores are lined with a conductive material extending past the substrate contact surface.  
     
     
         53 . The apparatus of  claim 52 , wherein the plurality of pores have an adjustable length.  
     
     
         54 . The apparatus of  claim 52 , wherein each of the plurality of pores are lined with graphite extending past the substrate contact surface an equal longitudinal distance.  
     
     
         55 . The apparatus of  claim 45 , wherein the anode spacer comprises a plurality of anode spacers.  
     
     
         56 . A method for plating a metal layer on a substrate, comprising: 
 positioning a substrate having recessed locations and raised locations in a plating cell;    positioning an anode spacer having a plurality of pores immediate a deposition surface of the substrate; and    flowing a plating solution having a higher resistance than the plurality of pores through the plurality of pores thereby plating the recessed locations until the substrate is in contact with the plurality of pores.    
     
     
         57 . The method of  claim 56 , further comprising rotating the anode spacer in relation to the deposition surface.  
     
     
         58 . The method of  claim 56 , wherein the plurality of pores extend through the anode spacer.  
     
     
         59 . The method of  claim 56 , wherein flowing a plating solution through the plurality of pores comprises flowing the plating solution through a plurality of pores lined with a conductive material extending through the anode spacer.  
     
     
         60 . The method of  claim 56 , wherein flowing a plating solution through the plurality of pores comprises flowing the plating solution through a plurality of pores extending through the anode spacer lined with a conductive material selected from the group essentially comprising gold, platinum, and graphite.  
     
     
         61 . The method of  claim 56 , wherein positioning the anode spacer comprises positioning a plurality of anode spacers in contact with the anode extending toward the deposition surface.  
     
     
         62 . The method of  claim 61 , wherein the plurality of spacers are composed of a conductive material.