system for plating a conductive substrate, and a substrate holder for holding a conductive substrate during plating thereof

Abstract

A system for plating a conductive substrate is provided. The system comprises a conductive substrate, comprising a first and a second conductive side, wherein said first side of the conductive substrate is to be plated. Furthermore, the system comprises a substrate holder with an attachment means, for attaching the conductive substrate to the substrate holder, such that a first surface of the substrate holder faces the second side of the conductive substrate. The substrate holder also comprises a resilient contact means, attached to the first surface of the substrate holder, said resilient contact means being connectable to a first external potential. The second side of the conductive substrate is provided with an insulating material exposing the second side of the conductive substrate, such that at least one contact area is provided, wherein the resilient contact means is in contact with the exposed second side in said at least one contact area. A substrate holder therefore is also provided.

1 . A system for plating a conductive substrate, said system comprising:
 (i) a conductive substrate, comprising a first and a second conductive side, wherein said first side of the conductive substrate is to be plated; and   (ii) a substrate holder, said substrate holder comprising:
 an attachment means, for attaching the conductive substrate to the substrate holder, such that a first surface of the substrate holder faces the second side of the conductive substrate; and 
 a resilient contact means attached to the first surface of the substrate holder, said resilient contact means being connectable to a first external potential, wherein 
   a first portion of the second side of the conductive substrate is provided with an insulating material, and a second portion of the second side of the conductive substrate forms at least one contact area; wherein the resilient contact means is in contact with at least one contact point in said at least one contact area.   
     
     
         2 . The system according to  claim 1 , wherein the first and the second portions of said second side of the conductive substrate are arranged such that said insulating material forms at least one cavity, wherein said at least one contact area is provided in said cavity. 
     
     
         3 . The system according  claim 1 , wherein an edge insulating layer ( 103 C), comprising at least one layer of at least one electrically insulating material, covers the edge of the conductive substrate ( 102 ). 
     
     
         4 . The system according to  claim 1 , wherein the at least one contact area covers at least 50% of a diagonal of said first side. 
     
     
         5 . The system according to  claim 1 , wherein the resilient contact means is in contact with said contact area in at least two contact points along a distance from the centre of the conductive substrate to the peripheral edge of the conductive substrate. 
     
     
         6 . The system according to  claim 1  or  5 , wherein at least one contact area is provided in the centre of the conductive substrate. 
     
     
         7 . The system according to  claim 1 , wherein the conductive substrate is sealingly attached to the substrate holder, such that electrolyte solution is prohibited from contacting the second side of the conductive substrate. 
     
     
         8 . The system according to  claim 1 , wherein the insulating material is patterned, such that several contact areas are provided on the second conductive side. 
     
     
         9 . The system according to  claim 8 , wherein the pattern is in the shape of concentric circles or circle segments. 
     
     
         10 . The system according to  claim 1 , wherein the arrangement of said contact means is patterned, such that several contact points are provided on the second conductive side. 
     
     
         11 . The system according to  claim 1 , wherein the attachment means comprises a clamping ring or edge gripper along the periphery of the substrate holder ( 101 ), or a pressure providing means and an airtight seal, said airtight seal being located along the periphery of the substrate holder ( 101 ). 
     
     
         12 . The system according to  claim 11 , wherein the clamping ring ( 302 ) or edge gripper and the substrate holder ( 101 ) are linked to each other by guiding elements ( 501 ), spaced along the periphery of the substrate holder ( 101 ), said guiding elements ( 501 ) being connected to an actuator, said actuator being adapted to lower to a loading/unloading position and/or raise to a processing position. 
     
     
         13 . The system according to  claim 1 , comprising at least two contact means, wherein a first resilient contact means is connectable to the first external potential, and a second resilient contact means is connectable to a second external potential. 
     
     
         14 . A substrate holder for holding a conductive substrate during plating thereof, comprising
 an attachment means, for attaching the conductive substrate to the substrate holder, such that a first surface of the substrate holder faces the second side of the conductive substrate; and resilient contact means, attached to the first surface of the substrate holder and connectable to at least one external potential.   
     
     
         15 . The substrate holder according to  claim 14 , wherein the arrangement of said contact means is patterned, such that several contact points are provided on the second side of the conductive substrate. 
     
     
         16 . The substrate holder according to  claim 14 , wherein the contact means comprises interconnection structure ( 701 B), distributed on the first surface of the substrate holder, interconnecting resilient contact elements ( 701 A). 
     
     
         17 . The substrate holder according to  claim 16 , wherein the distribution of the interconnection structure ( 701 B) is in a shape selected from the group consisting of star shape, shape of concentric circles, or a combination of a shape of concentric circles and a star. 
     
     
         18 . The substrate holder according to  claim 16 , wherein the contact elements ( 701 A) are electrically connected in parallel with each other, through the interconnection structure ( 701 B), to a common potential node ( 702 ). 
     
     
         19 . The substrate holder according to  claim 16 , wherein the contact elements ( 701 A) are flexible/resilient in a direction perpendicular to said first surface. 
     
     
         20 . The substrate holder according to  claim 14 , comprising at least one duct ( 111 ) supplying overpressure or underpressure to the contact means ( 304 ) or to the space in between the substrate holder ( 101 ) and the conductive substrate or to the space in between the contact means and the substrate holder ( 101 ). 
     
     
         21 . The substrate holder according to  claim 20 , wherein the contact means ( 304 ) is movable in the direction perpendicular to said first surface by means of gas pressure supplied in a bellows of said contact means. 
     
     
         22 . The substrate holder according to  claim 20 , comprising pressure actuators ( 502 A,  502 B), connected to said at least one duct, the pressure actuators being able to hold a conductive substrate by underpressure, said pressure actuators being extendable and retractable to bring the conductive substrate into proximity of or away from the first surface of the substrate holder. 
     
     
         23 . The substrate holder according to  claim 20 , comprising an additional pressure chamber, provided in the bulk of the substrate holder ( 101 ), and connected to said duct, said additional pressure chamber being in communication with the contact means ( 304 ) or with the space in between the substrate holder ( 101 ) and the conductive substrate or with the space in between the contact means and the substrate holder ( 101 ). 
     
     
         24 . The substrate holder according to  claim 14 , wherein the contact means ( 304 ) are mounted on a member that is actuated by a linear motor, stepper motor, or rotational motor, such that the contact means ( 304 ) is movable in the direction perpendicular to said first surface. 
     
     
         25 . The substrate holder according to  claim 14 , wherein the contact means ( 304 ) comprises hooks, loops, or tubes, flexible/resilient in a direction perpendicular to said first surface. 
     
     
         26 . The substrate holder according to  claim 14 , wherein the contact means ( 304 ) may be attached to the first surface of the substrate holder ( 101 ), with at least one integrated lead in the substrate holder ( 101 ), said at least one lead connecting the contact means and at least one external potential. 
     
     
         27 . The substrate holder according to  claim 14 , wherein the contact means ( 1201 ), comprises contact elements ( 1201 A) mounted on a flexible resilient layer ( 1202 ) attached to the first surface of the substrate holder ( 101 ). 
     
     
         28 . The substrate holder according to  claim 27 , comprising a flexible conductive film ( 1203 ), arranged distally of the contact elements ( 1201 A). 
     
     
         29 . The substrate holder according to  claim 14 , comprising a rigid conducting layer ( 1302 ) proximally of the contact means ( 1301 A), said rigid conductive layer ( 1302 ) being electrically connected with the substrate holder  101 , and wherein the contact means ( 1301 A) is a conductive foil that comprises distally protruding conducting contact structures ( 1303 ). 
     
     
         30 . The substrate holder according to  claim 14 , comprising an elastic layer ( 1402 ) applied to the first surface of the substrate holder ( 101 ), wherein the contact element ( 1401 A) is a compliant and conductive foil distally of said conductive elastic layer ( 1402 ). 
     
     
         31 . The substrate holder according to  claim 20 , wherein the contact means ( 1501 A) is a thin electrically conductive foil, fixed to the first surface of the substrate holder ( 101 ) along the periphery of the substrate holder ( 101 ) by an airtight seal, said thin electrically conductive foil establishing a volume in between the first surface of the substrate holder and the thin electrically conductive foil, said volume being connected to at least one first duct. 
     
     
         32 . The substrate holder according to  claim 31 , wherein the contact means ( 1501 ) is divided into concentric circles, electrically insulated from each other. 
     
     
         33 . The substrate holder according to  claim 32 , wherein a trench ( 1503 ) formed between the circle segments, comprises valves ( 1502 ), arranged in the trench, said valves being connected to at least one second duct. 
     
     
         34 . The substrate holder according to  claim 16 , wherein the interconnection structure ( 701 B,  901 B,  1101 B) is provided with at least one resistor.