Method of Forming Electrically Isolated Structures Using Thin Dielectric Coatings

Abstract

Electrochemical fabrication processes and apparatus for producing multi-layer structures where each layer includes the deposition of at least two materials and wherein the formation of at least some layers including operations for providing coatings of dielectric material that isolate at least portions of a first conductive material from (1) other portions of the first conductive material, (2) a second conductive material, or (3) another dielectric material, and wherein the thickness of the dielectric coatings are thin compared to the thicknesses of the layers used in forming the structures. In some preferred embodiments, portions of each individual layer are encapsulated by dielectric material while in other embodiments only boundaries between distinct regions of materials are isolated from one another by dielectric barriers.

I claim: 
     
         1 . A method for forming a three dimensional structure from a plurality of adhered layers, comprising:
 (1) forming a plurality of layers comprising regions of a first conductive material and regions of a filler material, wherein regions of the first conductive material and regions of the filler material are conductively isolated from one another by a dielectric material and wherein at least one of the following conditions is met:
 (A) the dielectric material is deposited during the forming of the plurality of layers and which has a coating thickness less than a layer thickness; 
 (B) the dielectric material is (i) not located between those portions of two consecutive layers where the filler material on an upper layer overlies filler material on a lower layer and (ii) not located between portions of two consecutive layers where the first conductive material on the upper layer overlies the first conductive material on the lower layer; 
 (C) the dielectric material separates those portions of two consecutive layers where the filler material on the upper layer overlies the filler material on the lower layer; 
 (D) the dielectric material is located in interface regions between up-facing regions of the first conductive material and down-facing regions of the filler material; or 
 (E) the dielectric material is located in interface regions between up-facing regions of filler material and down-facing regions of the first conductive material. 
   
     
     
         2 . The method of  claim 1  wherein the forming of at least a number of the plurality of layers comprises the planarization of the first conductive material and the filler material to set a boundary level for each of the number of the plurality of layers. 
     
     
         3 . The method of  claim 1  wherein both the first conductive material and the filler materials form part of the final structure. 
     
     
         4 . The method of  claim 1  wherein at least one of the first conductive material and the filler material is a sacrificial material that is removed after forming the plurality of layers. 
     
     
         5 . The method of  claim 1  wherein a first layer of the plurality of layers is formed on a substrate and wherein the structure is released from the substrate after formation. 
     
     
         6 . The method of  claim 1  wherein a first layer of the plurality of layers is formed on a substrate and wherein the structure remains attached to the substrate when it is put into use. 
     
     
         7 . The method of  claim 1  wherein the coating thickness is less than 25% of the layer thickness. 
     
     
         8 . The method of  claim 1  wherein the coating thickness is less than 10% of the layer thickness. 
     
     
         9 . The method of  claim 1  wherein the coating thickness is less than 5% of the layer thickness. 
     
     
         10 . The method of  claim 1  wherein during the formation of each layer the first conductive material and the filler material are deposited so as to have thickness that are at least as great as the thickness of the respective layers on which they are deposited. 
     
     
         11 . The method of  claim 1  wherein at least one of the first conductive material or the filler material is a different material on two different layers. 
     
     
         12 . The method of  claim 1  wherein the formation of at least a portion of the plurality of layers comprises deposition of the first conductive material, deposition of the filler material, deposition of the dielectric material, and deposition of an additional material. 
     
     
         13 . The method of  claim 1  wherein the deposition of the first conductive material or the filler material comprises an electroplating or electroless plating. 
     
     
         14 . The method of  claim 1  wherein the filler material comprises a conductive material. 
     
     
         15 . The method of  claim 1  wherein the filler material comprises a dielectric material. 
     
     
         16 . A fabrication method for forming a multi-layer three-dimensional structure, comprising:
 (a) forming a first layer of the multi-layer structure, wherein the first layer comprises at least two materials;   (b) forming a plurality of successive layers of the structure with each successive layer adhered to a previously formed layer to build up the three-dimensional structure, where the forming of each of the plurality of successive layers comprises at least two deposition operations that deposit at least two materials, which may be the same or different from the materials deposited on a previously formed layer, and at least one planarization operation;   wherein the forming of at least a portion of the plurality of layers comprises the deposition of at least a thin coating material, that is different from the at least two materials, that at least partially encapsulates one of the at least two materials.   
     
     
         17 . A method for forming a multi-layer three-dimensional structure, comprising:
 (a) forming a first layer of the multi-layer structure, wherein the first layer comprises at least two materials;   (b) forming a plurality of successive layers of the structure with each successive layer adhered to a previously formed layer to build up the three-dimensional structure, where the forming of each of the plurality of successive layers comprises at least three deposition operations that deposit at least three materials, which may be the same or different from the materials deposited on a previously formed layer, and at least one planarization operation, wherein one of the deposited materials is a sacrificial material and two of deposited materials are structural materials; and   (c) after formation of the plurality of successive layers, removing at least a portion of the sacrificial material to release the structural material;   wherein at least one of the structural material forms thin coatings over at least a portions of the surfaces of the other of the structural materials.   
     
     
         18 . The method of  claim 17  wherein the thin coatings isolate the other of the structural material from the sacrificial material. 
     
     
         19 . The method of  claim 17  wherein the at least one of the structural materials comprises a dielectric material.