Methods and Apparatus for Forming Multi-Layer Structures Using Adhered Masks

Abstract

Numerous electrochemical fabrication methods and apparatus are provided for producing multi-layer structures (e.g. having meso-scale or micro-scale features) from a plurality of layers of deposited materials using adhered masks (e.g. formed from liquid photoresist or dry film), where two or more materials may be provided per layer where at least one of the materials is a structural material and one or more of any other materials may be a sacrificial material which will be removed after formation of the structure. Materials may comprise conductive materials that are electrodeposited or deposited in an electroless manner. In some embodiments special care is undertaken to ensure alignment between patterns formed on successive layers.

We claim: 
     
         1 . A method for forming a three-dimensional structure, comprising:
 (A) forming a plurality of successively formed layers, wherein each successive layer comprises at least two materials and is formed on and adhered to a previously formed layer, one of the at least two materials is a structural material and the other of the at least two materials is a sacrificial material, and wherein each successive layer defines a successive cross-section of the three-dimensional structure, and wherein the forming of each of the plurality of successive layers comprises:
 (i) depositing a first of the at least two materials; 
 (ii) depositing a second of the at least two materials; 
 (iii) planarizing the first and second materials to set a boundary level for the layer; and 
   wherein the forming of a given one of the plurality of successively formed layers comprises:
 (i) applying a 1st patternable mold material (PMM) on the layer; 
 (ii) patterning the 1st PMM to form a 1st pattern; 
 (iii) depositing a 1st material in the 1st pattern; 
 (iv) removing the 1st PMM to expose areas of the layer not having the 1st material deposited thereon; 
 (v) depositing a 2nd PMM over the layer; 
 (vi) patterning the 2nd PMM to form a 2nd pattern, the 2nd pattern including an aperture adjacent to the 1st material and exposing a top portion of the 1st material; 
 (vii) depositing a 2nd material in the 2nd pattern formed and over the exposed top portion of the 1st material; 
 (viii) removing the 2nd PMM to expose areas of the layer not having the 1st or 2nd materials deposited thereon; 
 (ix) depositing a third material over the 1st and 2nd materials and over the exposed areas of the layer; and 
 (x) planarizing the deposited first—third materials to set a boundary level for the given layer. 
   (B) after the forming of the plurality of successive layers, separating at least a portion of the sacrificial material from multiple layers of the structural material to reveal the three-dimensional structure.   
     
     
         2 . The method of  claim 1  wherein the PMM is a photoresist. 
     
     
         3 . The method of  claim 1  wherein the forming the three-dimensional structure comprises the forming of a plurality of three-dimensional structures simultaneously. 
     
     
         4 . The method of  claim 1  wherein at least one of the depositing steps comprises electroplating. 
     
     
         5 . The method of  claim 1  wherein the depositing of the first material comprises electroplating, the depositing of the second material comprises electroplating, and the depositing of the third material comprises electroplating. 
     
     
         6 . The method of  claim 1  wherein the first of the least two materials deposited is a structural material. 
     
     
         7 . The method of  claim 1  wherein the first of the least two materials deposited is a sacrificial material. 
     
     
         8 . The method of  claim 1  wherein the given one of the layers comprises at least two layers. 
     
     
         9 . An electroplating method for fabricating a multi-layer three-dimensional structure, comprising:
 (A) forming a first layer comprising depositing at least a first structural material and at least a first sacrificial material and planarizing the at least one deposited first structural material and the at least one deposited first sacrificial material to set a boundary level of the first layer;   (B) forming additional layers with an initial additional layer formed on and adhered to the first layer and with subsequent additional layers formed on and adhered to previously formed additional layers, wherein the forming of each additional layer comprises depositing at least one additional structural material and depositing at least one additional sacrificial material and planarizing the at least one deposited additional structural material and the at least one additional sacrificial material to set a boundary level for each additional layer;   (C) after forming the plurality of successive layers, etching away a portion of the sacrificial material from multiple layers of the structural material to reveal a portion of the three-dimensional structures,   wherein the steps of depositing and of planarizing during forming of a given one of the layers comprises:
 (i) applying a 1st patternable mold material (PMM) on the layer; 
 (ii) patterning the 1st PMM to form a 1st pattern; 
 (iii) depositing a 1st material in the 1st pattern; 
 (iv) removing the 1st PMM to expose areas of the layer not having the 1st material deposited thereon; 
 (v) depositing a 2nd PMM over the layer; 
 (vi) patterning the 2nd PMM to form a 2nd pattern, the 2nd pattern including an aperture adjacent to the 1st material and exposing a top portion of the 1st material; 
 (vii) depositing a 2nd material in the 2nd pattern formed and over the exposed top portion of the 1st material; 
 (viii) removing the 2nd PMM to expose areas of the layer not having the 1st or 2nd materials deposited thereon; 
 (ix) depositing a third material over the 1st and 2nd materials and over the exposed areas of the layer; and 
 (x) planarizing the deposited first—third materials to set a boundary level for the given layer, and 
 wherein at least one of the first—third materials is a structural material and at least one of the first—third materials is a sacrificial material. 
   
     
     
         10 . The method of  claim 9  wherein the PMM is a photoresist. 
     
     
         11 . The method of  claim 9  wherein the forming the three-dimensional structure comprises the forming of a plurality of three-dimensional structures simultaneously. 
     
     
         12 . The method of  claim 9  wherein at least one of the depositing steps comprises electroplating. 
     
     
         13 . The method of  claim 9  wherein the depositing of the first material comprises electroplating, the depositing of the second material comprises electroplating, and the depositing of the third material comprises electroplating. 
     
     
         14 . The method of  claim 9  wherein the given one of the layers comprises at least two layers. 
     
     
         15 . An electroplating method for fabricating a multi-layer three-dimensional structure, comprising:
 (A) forming a first layer comprising depositing at least a first structural material and at least a first sacrificial material and planarizing the at least one deposited first structural material and the at least one deposited first sacrificial material to set a boundary level of the first layer;   (B) forming additional layers with an initial additional layer formed on and adhered to the first layer and with subsequent additional layers formed on and adhered to previously formed additional layers, wherein the forming of each additional layer comprises depositing at least one additional structural material and depositing at least one additional sacrificial material and planarizing the at least one deposited additional structural material and the at least one additional sacrificial material to set a boundary level for each additional layer;   (C) after forming the plurality of successive layers, etching away a portion of the sacrificial material from multiple layers of the structural material to reveal a portion of the three-dimensional structures,   wherein the steps of depositing and of planarizing during forming of a given one of the layers comprises depositing first, second and third materials wherein a patternable mold material (PMM) is formed over the 1st deposited material and is patterned to form an aperture adjacent to the 1st material, the aperture exposing a side portion and a top portion of the 1st material and wherein the aperture receives the second material during depositing of the second material.   
     
     
         16 . The method of  claim 15  wherein the PMM is a photoresist. 
     
     
         17 . The method of  claim 15  wherein the forming the three-dimensional structure comprises the forming of a plurality of three-dimensional structures simultaneously. 
     
     
         18 . The method of  claim 15  wherein at least one of the depositing steps comprises electroplating. 
     
     
         19 . The method of  claim 15  wherein the depositing of the first material comprises electroplating, the depositing of the second material comprises electroplating, and the depositing of the third material comprises electroplating. 
     
     
         20 . The method of  claim 15  wherein the given one of the layers comprises at least two layers.