Method of and apparatus for forming three-dimensional structures integral with semiconductor based circuitry
First 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) separating the selected preformed mask from the substrate;
wherein the substrate comprises a semiconductor wafer or single die containing electrical circuitry and having contact pads to which structural material is to connect; and
wherein the process of contacting the contact pads with structural material comprises treating the wafer or die with a transition treatment and then applying a structural material to the contact pads by application of an electroless plating solution to the contact pads for a sufficient time to form a deposition of desired thickness.
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Accused Products
Abstract
Enhanced Electrochemical fabrication processes are provided that can form three-dimensional multi-layer structures using semiconductor based circuitry as a substrate. Electrically functional portions of the structure are formed from structural material (e.g. nickel) that adheres to contact pads of the circuit. Aluminum contact pads and silicon structures are protected from copper diffusion damage by application of appropriate barrier layers. In some embodiments, nickel is applied to the aluminum contact pads via solder bump formation techniques using electroless nickel plating. In other embodiments, selective electroless copper plating or direct metallization is used to plate sacrificial material directly onto dielectric passivation layers. In still other embodiments, structural material deposition locations are shielded, then sacrificial material is deposited, the shielding is removed, and then structural material is deposited. In still other embodiments structural material is made to attached to non-contact pad regions.
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Citations
26 Claims
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1. An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising:
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(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) separating the selected preformed mask from the substrate;
wherein the substrate comprises a semiconductor wafer or single die containing electrical circuitry and having contact pads to which structural material is to connect; and
wherein the process of contacting the contact pads with structural material comprises treating the wafer or die with a transition treatment and then applying a structural material to the contact pads by application of an electroless plating solution to the contact pads for a sufficient time to form a deposition of desired thickness. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising:
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(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) separating the selected preformed mask from the substrate;
wherein the substrate comprises a semiconductor wafer or single die containing electrical circuitry and having contact pads to which structural material is to connect; and
wherein the process of forming a conductive layer over a surface of the wafer or die comprises;
(a) shielding at least the contact pads with a shielding material;
(b) depositing a sacrificial material to unshielded regions using at least one of direct metallization or direct plating or electroless deposition;
(c) removing the shielding after a deposition of the sacrificial material; and
(d) depositing a structural material to the contact pads. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. An electrochemical fabrication process for producing a three-dimensional structure from a plurality of adhered layers, the process comprising:
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(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) separating the selected preformed mask from the substrate;
wherein the substrate comprises a semiconductor wafer or single die containing electrical circuitry and having contact pads to which structural material is to connect and having regions of dielectric where structural material is to adhere; and
wherein the process of contacting the structural material to regions of dielectric material comprises depositing a conductive base material, in a patterned or unpatterned formation, depositing structural material to at least selected locations of the base material and, if base material exists in any regions which are not overlaid by structural material, subsequently removing any such base material that is not overlaid.
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Specification