Methods and apparatus for monitoring deposition quality during conformable contact mask plating operations

Abstract

Electrochemical fabrication (e.g. EFAB) processes and apparatus are disclosed that provide monitoring of at least one electrical parameter (e.g. voltage) during selective deposition where the monitored parameter is used to help determine the quality of the deposition that was made. If the monitored parameter indicates that a problem occurred with the deposition, various remedial operations may be undertaken to allow successful formation of the structure to be completed.

We claim:  
     
         1 . An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising: 
 (A) selectively depositing at least a portion of a layer onto the substrate, wherein the substrate may comprise previously deposited material;    (B) forming a plurality of layers such that successive layers are formed adjacent to and adhered to previously deposited layers, wherein said forming comprises repeating operation (A) a plurality of times;    wherein at least a plurality of the selective depositing operations comprise: 
 (1) locating a mask on, or in proximity to, a substrate;  
 (2) in presence of a plating solution, conducting an electric current between an anode and the substrate through the at least one opening in the mask, such that a selected deposition material is deposited onto the substrate to form at least a portion of a layer; and  
 (3) removing the mask from the substrate; and  
   wherein during formation of a given layer, a voltage between the anode and cathode is monitored.    
     
     
         2 . The process of  claim 1 , wherein a plurality of layers comprise at least one structural material and at least one sacrificial material.  
     
     
         3 . The process of  claim 1  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 locating of a mask on, or in proximity to, a substrate comprises contacting the substrate and the dielectric material of a selected preformed mask.  
 
     
     
         4 . The process of  claim 1  wherein the locating of a mask on, or in proximity to, a substrate comprises forming and adhering a patterned mask to the substrate.  
     
     
         5 . The process of  claim 1  wherein, based at least in part on the monitored voltage, a conclusion is reached that the deposition for a given layer is not acceptable, wherein the process additionally comprises: 
 (A) removing at least a portion of the material deposited in association with the given layer; and  
 (B) repeating the deposition for at least a portion of the given layer.  
 
     
     
         6 . The process of  claim 5  wherein the conclusion is also based on a visual inspection of the resulting deposit for a given layer.  
     
     
         7 . The process of  claim 5  wherein the measured voltage profile for at least one layer is indicative of flash.  
     
     
         8 . The process of  claim 5  wherein the comparison of the measured voltage profile to the anticipated voltage profile is capable of indicating the occurrence of flash.  
     
     
         9 . The method of  claim 5  wherein the measured voltage profile for at least one layer is indicative of shorting.  
     
     
         10 . The method of  claim 5  wherein the comparison of the measured voltage profile to the anticipated voltage profile is capable of indicating the occurrence of shorting.  
     
     
         11 . An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising: 
 (A) selectively depositing at least a portion of a layer onto the substrate, wherein the substrate may comprise previously deposited material;    (B) forming a plurality of layers such that successive layers are formed adjacent to and adhered to previously deposited layers, wherein said forming comprises repeating operation (A) a plurality of times;    wherein at least a plurality of the selective depositing operations comprise: 
 (1) locating a mask on, or in proximity to, a substrate;  
 (2) in presence of a plating solution, conducting an electric current between an anode and the substrate through the at least one opening in the mask, such that a selected deposition material is deposited onto the substrate to form at least a portion of a layer; and  
 (3) removing the mask from the substrate; and  
   wherein during, or after, formation of a given layer, the layer is inspected or formation parameters are compared to anticipated parameter values such that if it is determined that the layer was not formed correctly, at least a portion of material deposited in association with the layer is removed and replacement material is deposited.    
     
     
         12 . The process of  claim 11 , wherein a plurality of layers comprise at least one structural material and at least one sacrificial material.  
     
     
         13 . The process of  claim 11  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 locating of a mask on, or in proximity to, a substrate comprises contacting the substrate and the dielectric material of a selected preformed mask.  
 
     
     
         14 . The process of  claim 11  wherein the inspection comprises monitoring an electrical characteristic of a selective deposition operation.  
     
     
         15 . The process of  claim 14  wherein the electrical characteristic comprises a voltage between the anode and the cathode during conduction of the electric current.  
     
     
         16 . The process of  claim 14  wherein the monitoring occurs during formation of substantially all layers of the plurality.  
     
     
         17 . The process of claims  15  wherein the monitored voltage for each layer comprises a measurement of a voltage profile over deposition time for each layer.  
     
     
         18 . The process of  claim 17  wherein at least two points of the measured voltage profile for a given layer are used in making a comparison to an anticipated voltage profile, and based at least in part on the result of the comparison, a conclusion is reached as to whether or not the deposition was acceptable.  
     
     
         19 . The process of  claim 11  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 11  wherein the plurality of selective depositions comprise the deposition of a plurality of different materials.  
     
     
         21 . The process of  claim 11  wherein at least a portion of one layer is formed by a non-electroplating deposition process.  
     
     
         22 . The process of  claim 11  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 11  wherein the selective depositing for each of a number of layers comprises at least two selective depositions.  
     
     
         24 . The process of  claim 11  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.  
     
     
         25 . The process of  claim 21  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.  
     
     
         26 . A conformable contact masking process for producing a structure, wherein the process comprises: 
 (A) supplying at least one preformed mask that 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 the at least one mask comprises a support structure that supports the patterned dielectric material; and    (B) selectively depositing at least a portion of a layer onto a substrate, comprising: 
 i) contacting the substrate and the dielectric material of the preformed mask;  
 ii) in presence of a plating solution, conducting an electric current through the at least one opening in the selected mask between an anode and the substrate such that a selected deposition material is deposited onto the substrate to form at least a portion of a layer; and  
 iii) separating the selected preformed mask from the substrate; and  
   wherein during, or after, formation of a given layer, the layer is inspected, or formation parameters are compared to anticipated parameter values, such that if it is determined that the layer was not formed correctly, at least a portion of material deposited in association with the layer is removed and replacement material is deposited.