Conformable contact masking methods and apparatus utilizing in situ cathodic activation of a substrate

Abstract

Electroplating processes (e.g. conformable contact mask plating and electrochemical fabrication processes) that include in situ activation of a surface onto which a deposit will be made are described. At least one material to be deposited has an effective deposition voltage that is higher than an open circuit voltage, and wherein a deposition control parameter is capable of being set to such a value that a voltage can be controlled to a value between the effective deposition voltage and the open circuit voltage such that no significant deposition occurs but such that surface activation of at least a portion of the substrate can occur. After making electrical contact between an anode, that comprises the at least one material, and the substrate via a plating solution, applying a voltage or current to activate the surface without any significant deposition occurring, and thereafter without breaking the electrical contact, causing deposition to occur.

I claim:  
     
         1 . A method for activating a surface of a substrate onto which a metal will be deposited by electrodeposition, comprising: 
 (A) supplying a substrate onto which one or more depositions may have occurred, wherein the substrate has a surface to be activated prior to occurrence of a deposition of at least one additional material;    (B) contacting a plating solution and the substrate;    (C) contacting the plating solution and an activation anode; and    (D) applying a voltage or current between the activation anode and the substrate at a level and for a time such that at least partial activation of at least a portion of the substrate surface occurs without significant deposition of the at least one additional material occurring onto the surface, and thereafter without separating the substrate from the plating solution, applying a voltage or current between a deposition anode and the substrate at a level and for a time so as to cause deposition of the at least one additional material.    
     
     
         2 . The process of  claim 1  wherein the deposition anode comprises the activation anode.  
     
     
         3 . The process of  claim 1  wherein the deposition anode and the activation anode are different.  
     
     
         4 . The process of  claim 1  wherein the at least one additional deposition comprises a deposition of nickel.  
     
     
         5 . The process of  claim 4  wherein the at least portion of the substrate surface that is activated comprises nickel.  
     
     
         6 . An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising: 
 (A) depositing a first material onto the substrate to form a portion of a layer and depositing at least a second material to form another portion of the layer, wherein the substrate may comprise previously deposited material; and    (B) forming a plurality of layers such that each successive layer is formed adjacent to and adhered to a previously deposited layer, wherein said forming comprises repeating operation (A) a plurality of times;    wherein at least a plurality of the selective depositing operations comprise: 
 (1) contacting the substrate and a patterned mask having at least one opening;  
 (2) in presence of a plating solution, conducting an electric current between an anode and the substrate, which functions as a cathode, through the at least one opening in the mask, such that the selected one of the first or second deposition materials is deposited onto the substrate to form at least a portion of a layer; and  
 (3) separating the mask from the substrate;  
  wherein for a plurality of layers, in the presence of a plating solution, applying a current between an activation anode and the substrate, which functions as a cathode, at such a level and for such a time that at least partial activation of at least a portion of a surface of the substrate occurs without significant deposition of material occurring, and then without separating the substrate and the plating solution, applying a current between a deposition anode and the substrate which functions as a cathode, at such a level so as to cause deposition of a desired one of the first or second materials.  
   
     
     
         7 . The process of  claim 18  additionally comprising: 
 (C) supplying a plurality of preformed masks, wherein each mask comprises a patterned dielectric material that includes at least one opening through which deposition can take place during the formation of at least a portion of a layer, and wherein each mask comprises a support structure that supports the patterned dielectric material; and  
 wherein the contacting of the substrate and the patterned mask comprise contacting a selected one of the preformed masks to the substrate.  
 
     
     
         8 . The process of  claim 18  wherein the contacting of the substrate and the patterned mask comprise forming and adhering a patterned mask to the substrate.  
     
     
         9 . The process of  claim 18  wherein the selected one and the desired one are the same.  
     
     
         10 . The process of  claim 18  wherein the selected one and the desired one are different.  
     
     
         11 . The process of  claim 6  wherein the deposition anode comprises the activation anode.  
     
     
         12 . The process of  claim 6  wherein the deposition anode and the activation anode are different.  
     
     
         13 . The process of  claim 6  wherein the deposition of the first or second material that occurs after activation comprises a deposition of nickel.  
     
     
         14 . The process of  claim 13  wherein the at least portion of the substrate surface that is activated comprises nickel.  
     
     
         15 . An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising: 
 (A) supplying at least one material to be deposited, wherein the at least one material has an effective deposition voltage that is higher than an open circuit voltage, and wherein a deposition control parameter is capable of being set to such a value that a voltage can be controlled to a value between the effective deposition voltage and the open circuit voltage such that no significant deposition occurs but such that surface activation of at least a portion of the substrate can occur;    (B) forming a plurality of layers by depositing one or more materials which include the at least one material, wherein each successive layer is formed adjacent to and adhered to a previously deposited layer,    wherein after making electrical contact between an anode and the substrate via a plating solution, setting the deposition control parameter to at least one value and for a time such that at least a portion of the surface of the substrate is activated without any significant deposition occurring, and thereafter without breaking the electrical contact, applying a current between the anode and the substrate such that deposition of the at least one material occurs,    wherein the deposition of the at least one material or a deposition of at least one other material comprises: 
 (1) contacting or placing in proximity a patterned mask having at least one opening and a substrate;  
 (2) in presence of a plating solution, conducting an electric current between an anode and the substrate, which functions as a cathode, through the at least one opening in the mask, such that one of the at least one deposition material or the other deposition material is deposited onto the substrate to form at least a portion of a layer, after which the mask is removed from the substrate.  
   
     
     
         16 . The process of  claim 15  wherein the deposition of the at least one material comprises a deposition of nickel.  
     
     
         17 . The process of  claim 15  wherein the at least portion of the substrate that is activated comprises a previous deposition of the at least one material.  
     
     
         18 . The process of  claim 17  wherein the deposition that occurs after activation comprises a deposition of nickel.  
     
     
         19 . The process of  claim 15  wherein the formation of each of a number of layers comprise at least one blanket deposition as well as the selective deposition wherein for a given layer the selectively deposited material is different from a material deposited by blanket deposition.  
     
     
         20 . The process of  claim 15  wherein the plurality of selective depositions comprise the deposition of a plurality of different materials.  
     
     
         21 . The process of  claim 15  wherein at least a portion of one layer is formed by a non-electroplating deposition process.  
     
     
         22 . The process of  claim 15  wherein a plurality of depositions occur during the formation of each of a number of layers wherein at least one of the depositions on each of the number of layers deposits copper and at least one of the other depositions on the number of layers deposits nickel.  
     
     
         23 . The process of  claim 15  wherein the selective depositing for each of a number of layers comprises at least two selective depositions.  
     
     
         24 . The process of  claim 15  wherein a number of the plurality of preformed mask share a common support structure.  
     
     
         25 . The process of  claim 15  wherein a number of the plurality of layers are each formed by depositing at least one structural material using at least one deposition and by depositing at least one sacrificial material by using at least one other deposition.  
     
     
         26 . The process of  claim 15  wherein at least a portion of the at least one sacrificial material is removed after formation of a plurality of layers to reveal a three-dimensional structure comprised of at least one structural material.  
     
     
         27 . The process of  claim 15  wherein, for each of a plurality of masks, the support for the conformable material for a mask comprises the anode involved in the deposition associated with the use of the mask.  
     
     
         28 . The process of  claim 15  wherein, for each of a plurality of masks, the support for the conformable material for a mask is a porous medium which does not act as the anode during a deposition associated with the use of the mask.  
     
     
         29 . The process of  claim 15  wherein different masks are used during the deposition associated with the formation of at least two different layers.  
     
     
         30 . The process of  claim 15  wherein the same mask is used during the deposition associated with the formation of at least two different layers.  
     
     
         31 . The process of  claim 15  wherein the separating of the selected preformed mask occurs without breaking contact with sidewalls of the material deposited through the at least one opening while deposition continues to occur such that a deposition thickness continues to increase such that it exceeds a height that would have been practical if the entire deposition would have been attempted without separating the mask during plating.  
     
     
         32 . The process of  claim 15  where a thickness of the conformable material of at least one selected mask is less than 100 μm and is more preferably less than 50 μm.  
     
     
         33 . The process of  claim 15  wherein the formation of at least a plurality of layers additionally comprises removing a portion of the deposited material from the substrate such that a desired surface level is obtained.  
     
     
         34 . An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising: 
 forming a plurality of layers, wherein each layer is formed from the deposition of one or more materials, and wherein each successive layer is formed adjacent to and adhered to a previously deposited layer, wherein said forming comprises: 
 (A) contacting the substrate and a patterned mask having at least one opening;  
 (B) in presence of a plating solution, conducting an electric current between an anode and the substrate, which functions as a cathode, through the at least one opening in the mask, such that the first deposition material is deposited onto the substrate to form at least a portion of a layer; and  
 (C) separating the mask from the substrate; and  
 wherein for a plurality of layers, in the presence of a plating solution, applying a current between an activation anode and the substrate, which functions as a cathode, at such a level and for such a time that at least partial activation of at least a portion of the substrate surface occurs without significant deposition of material occurring, and then without separating the substrate and the plating solution, applying a current between a deposition anode and the substrate, which functions as a cathode, at such a level so as to cause deposition of a second material which may be different from or the same as the first material.  
   
     
     
         35 . The process of  claim 34  wherein the deposition anode comprises the activation anode.  
     
     
         36 . The process of  claim 34  wherein the deposition anode and the activation anode are different.  
     
     
         37 . The process of  claim 34  wherein the deposition that occurs after activation comprises a deposition of nickel.  
     
     
         38 . The process of  claim 37  wherein the at least portion of the substrate surface that is activated comprises nickel.