High speed 3D metallization printing

Abstract

To provide a system and a method including an anode substrate for printing metal wiring on a substrate.SOLUTION: A plurality of anodes is disposed on one side of the anode substrate with a first predetermined gap between adjacent ones of the plurality of anodes. A first plurality of fluid apertures have one end located between the plurality of anodes. A plurality of control devices are configured to selectively supply current to the plurality of anodes, respectively. The anode substrate is placed within the second predetermined gap of the workpiece substrate containing the metal seed layer. The ratio of the second predetermined gap to the first predetermined gap is in the range of 0.5:1 to 1.5:1. An array controller is configured to energize selected anodes of the plurality of anodes using corresponding control devices of the plurality of control devices while an electrolyte solution is supplied through the first plurality of fluid holes between the anode substrate and the workpiece substrate.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Application No. 62 / 958,930, filed January 9, 2020. The entire disclosures of the above-referenced applications are incorporated herein by reference.

[0002] The present disclosure relates to substrate processing systems, and more particularly to printing semiconductor electrical interconnects. [Background technology]

[0003] The background description provided herein is intended to present the contents of the present disclosure generally. Work by the presently named inventors within the scope of what is described in this Background section, as well as aspects of the description that may not otherwise be considered prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure.

[0004] Semiconductor wiring is typically formed using damascene processing, or through-resist processing and metallization. Damascene processing is typically used for higher aspect ratio through-silicon vias (TSVs) and wiring levels greater than three, with fluid holes and line wiring less than 0.5 micrometers (μm). Through-resist processing and metallization are typically used for packaging wiring formations with dimensions greater than about 1 μm and less than about three layers, such as redistribution layers, copper pillar bumping, and controlled collapse chip connection (C4) plated solder bumps.

[0005] Each of these processes uses several ancillary processes and hardware (photoresist application, lithography, photoresist development, photoresist strip and clean, chemical-mechanical polishing, wet etching) in addition to electroplating the desired current-carrying metal wiring lines / vias.

[0006] Damascene metallization processes (including through-silicon vias (TSVs)) form recessed cavities in a dielectric film (such as low-k (K) silicon dioxide (SiO2)). Etch areas are defined in the dielectric film using lithography as a mask or by forming a mask (such as a metal film). This step is usually followed by physical vapor deposition (PVD) metallization of the exposed surfaces, coating the exterior and interior surfaces with seed and barrier layers (typically copper (Cu) and tantalum (Ta), titanium (Ti), titanium nitride (TiN), or tantalum nitride (TaN)).

[0007] PVD metallization typically has high sidewall coverage selectivity so that the edge walls of the damascene structure, especially the bottom edge walls of the structure, are sufficiently covered to allow complete electrical connection and bottom-up fill of plating. The recessed structure is then plated from the "bottom-up," and chemical-mechanical polishing (CMP) of the surface leaves isolated lines / vias below the general surface.

[0008] Through-resist processing and metallization are used to form bumps and / or lines, creating an interconnect structure above the general surface at the end of the process. Through-resist processing and metallization involves seeding the exposed surface (e.g., a blanket PVD metal layer of copper / 2000 Å on tantalum / 200 Å). Next, a dry photoresist film is applied, or a wet photoresist layer is applied using spin coating (drying and curing). The photoresist layer can be either positive-tone or negative-tone (exposed areas are either removed or remain after development). The photoresist is then exposed in a lithography step. The photoresist is then selectively removed by immersion in a developer appropriate for the particular type and chemical formulation of photoresist. Residual photoresist remaining at the base of the features after development is removed by exposing the wafer surface to oxygen plasma (sometimes referred to as the "descum step"). Typically, during this step, oxygen end groups replace hydrophobic organic end groups on the photoresist surface, rendering the organic photoresist film more hydrophilic. The wafer then has a set of photoresist openings down to the seed layer, which are plated to fill these openings to form bumps, lines, a thick solder film (which is reflowed to form balls), or a thin layer of solder on top of the copper bumps to form copper / solder (e.g., Cu / SnAg) pillars. Summary of the Invention

[0009] A system for printing metal wiring on a substrate includes an anode substrate. A plurality of anodes are disposed on one side of the anode substrate with a first predetermined gap between adjacent anodes of the plurality of anodes. A first plurality of fluid holes have one end located between the plurality of anodes. A plurality of control devices are configured to selectively supply current to each of the plurality of anodes. The anode substrate is disposed within a second predetermined gap of a workpiece substrate including a metal seed layer. A ratio of the second predetermined gap to the first predetermined gap is in a range of 0.5:1 to 1.5:1. An array controller is configured to energize selected anodes of the plurality of anodes using corresponding control devices of the plurality of control devices while an electrolyte solution is supplied through the first plurality of fluid holes between the anode substrate and the workpiece substrate.

[0010] In other features, the plurality of anodes comprises inert anodes, and the electrolyte solution includes metal cations. The anode substrate further includes a second plurality of fluid holes positioned between the plurality of anodes for removing the electrolyte solution between the anode substrate and the workpiece substrate. The anode substrate includes a plenum in fluid communication with an electrolyte source. A manifold is disposed adjacent to the anode substrate and includes an inlet in fluid communication with the electrolyte source and an outlet in fluid communication with the first plurality of fluid holes.

[0011] In other features, a plurality of valves are disposed in the first plurality of fluid holes, respectively. The plurality of valves are configured to selectively control the flow of the electrolyte solution through the first plurality of fluid holes. An array controller is configured to control the valves. A positioning device is configured to adjust the position of at least one of the workpiece substrate and the anode substrate. The positioning device moves at least one of the workpiece substrate and the anode substrate during printing of the metal wiring.

[0012] In other features, the array controller is configured to: a) print a first metal trace on the workpiece substrate; b) cause the positioning device to move the workpiece substrate a second predetermined gap in at least one of a lateral direction and a vertical direction relative to the anode substrate; and c) print a second metal trace on the workpiece substrate. The array controller is configured to repeat b) and c) one or more times.

[0013] In other features, the first predetermined gap is in the range of 0.1 micrometers to 100 micrometers.The first predetermined gap is in the range of 0.5 micrometers to 10 micrometers.

[0014] In other features, a plurality of valves are associated with each of the plurality of fluid holes, and the array controller is configured to control the valves to adjust at least one of a direction and a pattern of fluid flow from the plurality of fluid holes disposed adjacent each of the plurality of anodes. The plurality of control devices are selected from the group consisting of switches and fuses.

[0015] A method for printing metal wiring on a substrate includes providing a workpiece substrate including one or more underlayers, a barrier / adhesion layer, and a seed layer; and providing an anode substrate including a plurality of anodes disposed on one side of the substrate and a first plurality of holes having edges between the plurality of anodes. The plurality of anodes are spaced apart from adjacent anodes of the plurality of anodes by a first predetermined gap. The method includes placing the anode substrate within a second predetermined gap of the workpiece substrate including the metal seed layer. The ratio of the second predetermined gap to the first predetermined gap is in the range of 0.5:1 to 1.5:1. The method includes applying a current to selected anodes of the plurality of anodes while supplying an electrolyte solution through the first plurality of holes between the anode substrate and the workpiece substrate.

[0016] In other features, the plurality of anodes comprises inert anodes. The method includes disposing a second plurality of fluid holes between the plurality of anodes and removing an electrolyte solution from between the anode substrate and the workpiece substrate. The method includes supplying the electrolyte solution to a plenum in the anode substrate. The method includes attaching a manifold to the anode substrate with an outlet of the manifold in fluid communication with the first plurality of fluid holes. The method includes controlling flow through the first plurality of fluid holes using a plurality of valves.

[0017] In other features, the method includes adjusting the position of at least one of the workpiece substrate and the anode substrate, the method including a) printing first metal traces on the workpiece substrate, b) moving the workpiece substrate relative to the anode substrate in at least one of a lateral direction and a vertical direction, and c) printing second metal traces on the workpiece substrate.

[0018] In other features, the method includes repeating b) and c) one or more times. The first predetermined gap is in the range of 0.1 micrometers to 100 micrometers. The first predetermined gap is in the range of 0.5 micrometers to 10 micrometers.

[0019] In other features, the method includes controlling fluid flow within a first plurality of fluid holes using a respective plurality of valves, and controlling the valves to adjust at least one of a direction and a pattern of fluid flowing from the first plurality of fluid holes disposed adjacent each of the plurality of anodes.

[0020] In other features, the method includes adjusting the position of at least one of the workpiece substrate and the anode substrate during printing of the metal traces.

[0021] A method for printing metal wiring on a substrate includes providing a workpiece substrate including one or more underlayers, a barrier / adhesion layer, and a seed layer, and providing an anode substrate including a plurality of anodes disposed on one side of the substrate. The plurality of anodes are spaced apart from adjacent anodes of the plurality of anodes by a first predetermined gap. The method includes disposing the anode substrate within a second predetermined gap of the workpiece substrate including the metal seed layer. The ratio of the second predetermined gap to the first predetermined gap is in the range of 0.5:1 to 1.5:1. The method includes energizing selected anodes of the plurality of anodes while supplying an electrolyte solution between the anode substrate and the workpiece substrate, separating the anode substrate from the workpiece substrate, disposing the anode substrate within the second predetermined gap of the workpiece substrate, and energizing selected anodes of the plurality of anodes while supplying an electrolyte solution between the anode substrate and the workpiece substrate.

[0022] In other features, the method includes agitating the electrolyte solution after separating the anode substrate and the workpiece substrate, and disposing the anode substrate within the second predetermined gap of the workpiece substrate after agitating the electrolyte solution.

[0023] In other features, the plurality of anodes comprises inert anodes.The method includes supplying an electrolyte solution between an edge of the anode substrate and the workpiece substrate.

[0024] In other features, the method includes adjusting the position of at least one of the workpiece substrate and the anode substrate. The method includes: a) printing a first metal trace on the workpiece substrate; b) moving the workpiece substrate relative to the anode substrate in at least one of a lateral direction and a vertical direction; and c) printing a second metal trace on the workpiece substrate. The method includes repeating b) and c) one or more times. The first predetermined gap is in the range of 0.1 micrometers to 100 micrometers. The first predetermined gap is in the range of 0.5 micrometers to 10 micrometers. The method includes adjusting the position of at least one of the workpiece substrate and the anode substrate during printing of the metal trace.

[0025] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0026] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0027] [Figure 1A] FIG. 1A is a functional block diagram of a processing system for metal printing of metal traces on a workpiece substrate according to the present disclosure.

[0028] [Figure 1B] FIG. 1B is a flowchart of an example method for printing metal traces on a workpiece substrate according to the present disclosure.

[0029] [Figure 2] FIG. 2 is a graph showing the pressure drop per centimeter for the flow of electrolyte solution through the array as a function of gap size.

[0030] [Figure 3]FIG. 3 is a flow chart of an example method for printing metal traces on a workpiece substrate according to the present disclosure.

[0031] [Figure 4] FIG. 4 is a functional block diagram of a processing system for metal printing of metal traces on a workpiece substrate according to the present disclosure.

[0032] [Figure 5A] FIG. 5A is a perspective view of an anode substrate including an array of anodes according to the present disclosure.

[0033] [Figure 5B] FIG. 5B is a cross-sectional side view of another example anode substrate including an anode and an external manifold according to the present disclosure.

[0034] [Figure 5C] FIG. 5C is a cross-sectional side view of an example anode substrate including an integrated plenum according to the present disclosure.

[0035] [Figure 5D] FIG. 5D is a cross-sectional side view of an example anode substrate including first and second integrated plenums according to the present disclosure.

[0036] [Figure 5E] FIG. 5E is a side cross-sectional view of an example anode substrate including first and second integrated plenums and valves according to the present disclosure.

[0037] [Figure 6A] FIG. 6A is a diagram illustrating metal printing on a workpiece substrate according to the present disclosure. [Figure 6B] FIG. 6B illustrates printing metal on a workpiece substrate according to the present disclosure. [Figure 6C] FIG. 6C illustrates printing metal on a workpiece substrate according to the present disclosure. [Figure 6D] FIG. 6D illustrates metal printing on a workpiece substrate according to the present disclosure. [Figure 6E] FIG. 6E illustrates metal printing on a workpiece substrate according to the present disclosure. [Figure 6F] FIG. 6F illustrates metal printing on a workpiece substrate according to the present disclosure. [Figure 6G] FIG. 6G illustrates printing metal on a workpiece substrate according to the present disclosure.

[0038] [Figure 7] FIG. 7 is a plan view of the anode and electrolyte feed fluid holes of an anode substrate according to the present disclosure.

[0039] [Figure 8] FIG. 8 is a plan view of an adjacent anode and a group of surrounding electrolyte feed fluid holes of an anode substrate according to the present disclosure.

[0040] In the drawings, reference numbers may be reused to refer to similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION

[0041] Systems and methods according to the present disclosure relate to efficient and fast two-dimensional (2D) (or single layer) and / or three-dimensional (3D) (multilevel) metal printing processes with semiconductor wiring-scale resolution to form wiring at lower cost, using less equipment, and with higher productivity. More specifically, the systems and methods described herein can be performed without the common steps, equipment, and materials of photoresist lithography, development, dielectric etching, cleaning, and / or other steps described above.

[0042] Systems and methods according to the present disclosure relate to the formation of semiconductor-scale metal interconnect wires using a direct electrochemical printing process, in which the metal interconnect wires are deposited on a substrate including a metal seed layer by supplying a metal cation-containing electrolyte solution to a gap between a workpiece substrate and an anode of an anode substrate.

[0043] 1A, an example of a substrate processing system 100 for printing metal traces or other features on a substrate is shown. A workpiece substrate 120 includes one or more underlayers 122, a barrier / adhesion layer 124 disposed on the one or more underlayers 122, and a metal seed layer 126 disposed on the barrier / adhesion layer 124.

[0044] An anode substrate 130 includes an interconnect layer 132, a control device 133, and an array of anodes 134. In some examples, the control device 133 includes a switch, such as one or more transistors, fuses, and / or other control devices. In some examples, the anode substrate 130 is configured once and then reused. For example, a fuse is blown (to prevent power from reaching the anodes 134) or not blown (to allow power to reach the anodes 134). In other examples, the control device 133 includes a switch / transistor that is configured and reconfigured depending on the desired pattern generated by the anodes 134. In another example, an anode array is fabricated to have a layout associated with it that is useful for fabricating a specific layout of anodes, more specifically, a single interconnect design for the semiconductor film on a substrate where at least some of the anodes 134 are all connected to a common power source.

[0045] In some examples, the control device 133 operates in a binary mode, which includes being either on or off. In other examples, the control device 133 operates in a variable mode, which includes a range of values ​​between fully off and fully on. For example, the control device can be designed with a variable resistance, which allows the current to the control device and other elements to be individually controlled to allow different amounts of current to flow. While the anode 134 is shown as rectangular, oval, circular, polygonal, or other shapes can be used.

[0046] The wiring layer 132 provides routing and wiring connections including conductors, traces, vias, etc. from controllers, power supplies, and / or other devices located external to the anode substrate 130. By way of example only, the wiring layer 132 provides power and / or control signals to each of the control devices 133. Depending on their states, the control devices 133 selectively supply current to their anodes 134.

[0047] In some examples, the anodes 134 are arranged in a grid or array, with gaps g a The anodes 134 are uniformly spaced apart from adjacent anodes 134 by a gap g. In other examples, to simplify the anode substrate 130, the anodes 134 are not arranged in a grid, but are instead placed in predetermined locations (and no other locations) that correspond to the desired pattern to be printed. The workpiece substrate 120 and the anode substrate 130 are spaced apart by a gap g. s An electrolyte solution source 142, a pump 144, and / or one or more valves 146 are used to pump electrolyte solution through the gap g s can be supplied to

[0048] In some examples, the metal seed layer 126 includes 1000 Å of copper (Cu) deposited on the barrier / adhesion layer 124, both of which were deposited using a PVD deposition tool. In some examples, the barrier / adhesion layer 124 includes 100 Å of tantalum (Ta) deposited using PVD. The one or more layers 122 may include a silicon wafer, a glass substrate, an organic substrate, or the like. The electrolyte solution includes a metal salt and may include, for example, an aqueous copper sulfate solution. The electrolyte solution may further include an acid (e.g., sulfuric acid) to increase the conductivity of the solution and improve the throwing power of the solution, as well as one or more plating additives of different additive classes (e.g., plating accelerators, suppressors, levelers, grain refiners, etc.). Other electrolyte solutions may also be used, as known in the art.

[0049] Deposition occurs on the substrate by applying a negative (cathodic) potential to the metal seed layer 126 relative to a positive potential applied to one of the anode substrates 130, or anodes 134. In some examples, the anodes 134 of the anode substrates 130 can be switched on and off and generally provide the same voltage or current potential when on. In other examples, the anodes 134 of the anode substrates 130 can be switched on and off and controlled to provide varying voltage or current potentials.

[0050] The anode 134 of the anode substrate 130 and the seed layer 126 of the workpiece substrate 120 are positioned close to one another so that the electric field generated by the anode 134 of the anode substrate 130 does not have space to spread or diffuse and is therefore focused (proximity focused), writing with high selectivity to the area immediately adjacent the activated anode 134 of the anode substrate 130. In some examples, the shape of the anode is projected onto the seed layer in the form of metal traces.

[0051] A controller 160 may be used to control the state of the control device 133, the valve 146, the pump 144, and / or the positioning device 162. The positioning device 162 is used to position the workpiece substrate 120 and / or the anode substrate 130. In some examples, the positioning device 162 positions the workpiece substrate 120 and / or the anode substrate 130, and printing of metal traces is performed. The positioning device 162 then repositions the workpiece substrate 120 and / or the anode substrate 130, and printing of metal traces is performed on the same workpiece substrate 120. The process may involve plating, stopping plating, moving, and re-plating. Alternatively, the process may involve simply moving the workpiece relative to the anode substrate continuously at a constant speed with the anode energized / on, or moving at a time-variable speed. The direction of relative movement may also change during the plating process. These process steps can be repeated one or more times on the same workpiece substrate 120 to form a pattern of metal wiring.

[0052] 1B, a method 180 for printing traces on a substrate is shown. At 182, the substrate is aligned with the seed layer and anode substrate at a predetermined distance or gap g s At 184, an electrolyte solution is introduced into the gap g between the workpiece substrate and the anode substrate. s At 186, a selected anode of the anode substrate is energized. At 188, the method determines if the target thickness has been reached. If 188 is false, the method returns to 186 until the target thickness has been reached. Once the target thickness has been reached, the substrate is removed at 190.

[0053] Because the gap between the surface of the seed layer 126 and the anode 134 of the anode substrate 130 is small, the fluid volume and metal ion capacity in the electrolyte solution is also very small. Additionally, the ability of the electrolyte solution to take up and dissolve oxygen (formed at the anode 134 of the activated anode substrate 130) is limited without the nucleation / formation of gas bubbles.

[0054] Generally, electrodeposition of metal from metal ions in an electrolyte solution onto a metallized seed substrate requires that the substrate be at a potential lower than the reduction potential of the metal ions in solution. For example, to plate pure copper onto a copper seed wafer, the electrolyte solution must contain copper (and no other metals with more positive reduction potentials), and the potential of the metal film is made more negative / cathodic than the reduction potential of copper.

[0055] This is accomplished by applying a potential difference between the seed layer 126 and the selected anode 134 (and electrolyte solution). The controller 160 provides control signals to the control device 133 and to the selected one of the anodes 134 on the anode substrate 134.

[0056] The deposition rate of copper onto the seed layer 126 depends on how negative a reduction potential is applied and exists at various points across the surface of the seed layer 126. In other words, a more negative potential generally corresponds to a faster charge transfer rate or a higher surface reaction rate to reduce cupric ions to copper ions. The deposition rate also depends on the mass transfer resistance of the copper ions to reach the surface of the seed layer 126, which can be reduced by the flow strength as well as the temperature of the solution.

[0057] Anodes can generally be of two types: active or passive. Active anodes oxidize their own metal (e.g., copper anodes dissolve to form cupric ions). In other words, the anode is consumed in the process. In active applications, an array of anodes controls the physical location where plating occurs. Active applications have the advantage that they generally do not deplete or consume the electrolyte solution of metal ions in the thin gap between the anode 134 and the workpiece substrate 120.

[0058] However, active applications have the disadvantage of corrosion during processing, shortening the useful life of the anodes 134 in the substrate processing system. For example, unused anodes are not consumed, while used anodes are. Over time, active anodes recede relative to inactive anodes, which can cause reduced deposition rates and / or other problems over time.

[0059] In passive applications, the anode 134 of the anode substrate 130 is made of a corrosion-resistant, inert material. The inert anode is capable of electrochemically oxidizing the electrolyte elements (e.g., water) without being substantially oxidized or corroded itself. The inert anode 134 is made of a material that is dimensionally and oxidatively stable when exposed to the electrolyte solution. For example, the inert electrode can be made of one or more noble metals whose oxidation potential is positive relative to the oxidation potential of water (1.23 V vs. NHE), as well as other metals capable of forming stable oxide films and thereby oxidizing water without significant corrosion. For example, the anode can be made of gold, platinum, palladium, ruthenium, rhodium, niobium, vanadium, and alloys of these materials. Carbon (including various amorphous and graphite forms) can also be used for the inert anode if the composition of the electrolyte solution does not cause substantial oxidation.

[0060] The advantage of using a dimensionally stable inert anode is that the distance between the array surface and the workpiece surface is predictable and constant over time, but the use of an inert anode depletes the supply of metal ions in the electrolyte during deposition.

[0061] The two half-reactions that occur combine to produce the overall reaction in the system, which is: Workpiece / Substrate / Cathode Reduction: M +z +ze - →M Micro-inert anode array oxidation: z / 2*[2H2O→O2+2H + +2e - ] Overall Response: M +z +zH2O→M+z / 2 O2+zH +

[0062] where M +zis a dissolved metal ion (e.g., copper, nickel, tin, silver, etc.) with an oxidation state of z (e.g., z = +2 for cupric ion). Without replenishment, as half-reaction 1 proceeds and metal is deposited, the metal's ions become depleted in the small gap. The larger the gap, the more metal can be deposited. However, a small gap is maintained so that each separate anode writes only to the area directly across from its position. If the gap is larger than approximately 1:1 (gap distance / anode size), the electric field spreads out from the element, causing the plating area to become larger and potentially overlapping with the plating of adjacent anodes.

[0063] As a specific example of how quickly depletion of the metal ion supply in the gap can occur, consider a 50 μm anode 50 μm away from a substrate with an anode spacing of 100 μm. Copper metal is plated in this example from a concentrated (near-saturated) ambient temperature copper sulfate electrolyte solution (80 g / L or 1.25 M cupric ion). The volume of fluid in the gap is 100 μm x 100 μm x 50 μm = 500,000 μm 3 and 1.25e -10 Mol, 4.0e -8 1000µm of copper and 4400 cubic microns of copper. The copper is projected directly onto the substrate at a 50*50=250µm 2 ), 100% depletion of copper from the area above and around the anode results in a film less than 7 μm thick.

[0064] However, before exhaustion is reached, process efficiency declines, oxygen bubbles form on the anode, and hydrogen bubbles form on the substrate surface. The presence of bubbles in the gap or on the surface of the substrate or anode blocks the passage of current and stops the reaction. Because the anode size is 50 μm, the device was unable to produce 1:1 aspect ratio features (50 μm height and 50 μm width / length) or 3D printed patterns. Therefore, electrolyte replenishment is necessary.

[0065] Referring to the latter reaction, O2 generated at the surface of the anode first dissolves in the electrolyte solution in the gap. However, the solubility of O2 is very low (e.g., 8 ppm in water at ambient temperature), which quickly becomes supersaturated and nucleates to form oxygen bubbles. The oxygen bubbles are non-conductive and fill the gap area between the anode and the substrate surface. Current is diverted around the oxygen bubbles, which leads to uneven plating on the substrate, and eventually the oxygen bubbles stop the reaction completely.

[0066] While O2 in the electrolyte solution can be reduced at the substrate simultaneously with metal deposition, most metal surfaces plated onto the substrate are not catalytic to that type of reaction. Simultaneous reactions can also alter the efficiency of the metal deposition process, resulting in unpredictable deposition rates between the anodes. Therefore, in some examples, systems and methods according to the present disclosure circumvent this problem by replenishing the electrolyte in the gap.

[0067] Computer simulations of the current density distribution on the substrate under the condition of electrolyte ohmic resistance control were carried out by solving the Laplace equation for various gap values ​​under edge-boundary symmetry and non-flux boundary conditions. The activated anode was driven at 100 A / m 2 The current is assumed to generate a current density of 0.01 S / m. The current flows through a substrate held at a lower reference potential, such as ground. The electrolyte conductivity is set to 0.01 S / m, and the 1 μm anode has a gap of 0.75 to 3.5 μm.

[0068] Computer simulations have shown that using simulated electrolyte ohmic resistance control (also known as "primary current distribution" control), activated anodes on anode substrates produce clear, distinct plating images of the activated anode when the gap to feature size is 1.5 to 1 or less and 0.5 to 1 or greater. In other examples, the gap to feature size is 1.2 to 1 or less and 0.8 to 1 or greater. In other examples, the gap to feature size is 1.1 to 1 or less and 0.9 to 1 or greater.

[0069] A large gap would blur the image to the point of being useless, while a small gap would significantly improve the resolution of the metal wiring. This data shows that for packaging of miniature integrated circuits, where the scale is in the 1µm to 100µm range, or for the needs of front-end wiring, where the scale is typically 5-500nm, the gap needs to be very small, and a continuous process is possible by replenishing the supply of metal ions in the gap.

[0070] One approach to replenishing the gap with metal ions is to flow new fluid into the gap space from one side of the array / substrate and drain the waste / depleted material out the other side. For example, using a 25 μm gap and a reasonably productive deposition rate of 7 μm / min to form relatively large 25 μm features that are 25 μm high, the solution below the gap can be replaced approximately every 15 seconds (at which point approximately 1 / 4 of the ions in the gap are depleted without flow).

[0071] Because the gap is so small, the pressure required to create flow across it is high. For an array with a length and width of 30 cm and a gap of 50 μm, the volume of fluid in the gap is 4.5 cm. 3 and to replenish the plated material at a rate of 7 μm / min, 18 cm 3 A flow rate of 1000 vol / min is required. This flow is required regardless of gap size. As the gap gets smaller, the initial amount of metal ions available in the gap decreases linearly. Unless the plating rate is correspondingly reduced with gap size, the time to depletion decreases linearly. Therefore, in this mass-transport-limited process, a constant flow rate is used to maintain the same deposition rate for all gap sizes.

[0072] Referring now to Figure 2, the calculated pressure drop across the array required to keep the plating rate constant (e.g., 7 μm / min with the average gap concentration reduced from 80 g / L to 60 g / L) for various gap sizes on a 30 cm anode array per cm of array length. For a 25 μm sized gap, a 10 cm long array (probably the minimum useful length), a pressure of 68 kPa (10 psi) is applied, rapidly increasing to 550 kPa (80 psi) for a 12 μm gap.

[0073] The use of these pressures can tend to separate the workpiece substrate and the anode substrate, increasing the overall complexity of the system. Furthermore, this generally leads to material replenishment, with the upstream side of the electrolyte injection becoming substantially richer in copper than the downstream side. Because the substrate is a single coated surface and is essentially held at a single cathodic potential, the plating rate is significantly slower at the outlet side (downstream) of the flow than at the inlet side (upstream). In other words, the total potential drop is the same at each anode, but the mass transfer resistances are different, resulting in varying deposition rates.

[0074] Such a reduced concentration in the upstream anode gap space requires that more anodic potential be applied to the anode upstream of the anode substrate to compensate for the higher mass transfer resistance. Alternatively, this effect can be compensated for by having a different applied current or anodic potential at each anode at a given distance from the entry point. A control device 133 can be used to compensate for the higher mass transfer resistance experienced by the upstream anode to maintain the current density and ensure the same plating rate for each of the growing plating elements.

[0075] This approach has the disadvantage of requiring more complex wiring and power controllers. The upstream point generally operates under conditions of higher mass transfer polarization than the inlet anode. As a result, the plated metal does not form with the same, or sometimes poorer, grain structure, uniformity, shape, or efficiency. Given that oxygen accumulates in the gap from the anodic reaction, the inlet region of the array removes that oxygen as dissolved material, while the electrolyte in the downstream gap is likely to cumulatively take up oxygen from all upstream anodic events, nucleate, fill with bubbles, and operate at a lower efficiency.

[0076] Referring now to FIG. 3, the gap g s 3 shows an example of a method 300 for efficiently and without excessive pressure resupplying electrolyte solution within a workpiece substrate. The method 300 uses a cyclic gap formation and opening process. The workpiece substrate and the anode substrate are spaced apart at 312 by a predetermined gap g. s At 314, the electrolyte solution is introduced into the gap g between the workpiece substrate and the anode substrate. s At 318, selected anodes on the anode substrate are energized to define the wiring pattern. At 322, the method determines whether the target metal thickness has been reached. If not, then at 326, the method determines whether there is ion depletion in the gap. This determination can be time-based, measurement-based, or determined in another manner.

[0077] If 326 is false, the method returns to 318. If 326 is true, the method separates the workpiece substrate and the anode substrate while leaving both in the electrolyte solution. At 334, the electrolyte solution is optionally agitated near the surfaces of the workpiece substrate and / or the anode substrate.

[0078] In this process, the workpiece substrate or anode substrate is moved to a predetermined position (with a predetermined gap g sAfter plating the wafer and forming the structure for a predetermined period of time, the workpiece substrate and the anode substrate are moved apart while both are still covered in the electrolyte solution.

[0079] In some instances, the workpiece substrate or anode substrate is moved a distance of 10 times or more the plating gap distance. This allows new electrolyte to flow into the gap between the two components and enter from the edge of the anode substrate. This action improves flow and agitates the fluid near the surface and within the gap while the gap is open. The workpiece substrate and anode substrate are then moved together again to the target plating gap setting. This process may involve a series of iterations to align and form a precise gap between the array and the wafer across the range of the array.

[0080] 4-5E, an example anode substrate according to the present disclosure includes an electrolyte solution in a gap g s and / or gap g s The system includes one or more electrolyte delivery features, such as external manifolds and / or internal plenums, flow-through fluid holes, trenches, etc., for removing electrolyte solution from the system.

[0081] 4, the anode substrate 410 includes a plenum 418 and fluid holes 420 that extend from the plenum 418 to a first surface of the anode substrate 410 that faces the workpiece substrate 120. In some examples, the fluid holes 420 are located between the anodes 414. An electrolyte solution is supplied to the plenum 418 and passes through the fluid holes 420 to fill the gap g between the workpiece substrate 120 and the anode substrate 410. s are supplied to.

[0082] 5A-5E show other examples of anode substrates and fluid delivery. In FIG. 5A, anode substrate 500 includes anodes 534-11, 534-12, ..., and 534-MN (collectively anodes 534), where M and N are integers greater than 1). Holes 510 are shown from a first or lower surface of anode substrate 500 to a second or upper surface of anode substrate 500. For example, holes 510 for delivering and / or removing electrolyte solution are arranged between anodes 534 in rows or columns. For example, trenches 512 are arranged between anodes 534 in columns or rows on the first or upper surface to remove electrolyte solution. In this example, one or more external manifolds are used to deliver or remove electrolyte solution. In some examples, electrolyte solution flows from the manifolds through the holes, across the anodes 534, and into trenches 512.

[0083] 5B, a manifold 554 is attached to the underside of an anode substrate 552. The anode substrate 552 includes an anode 553. The manifold 554 includes a plenum 556 and holes 558 in fluid communication with the plenum 556. Holes 560 in the anode substrate 552 are aligned with holes 558 in the manifold 554.

[0084] In FIG. 5C, an anode substrate 570 includes an anode 574 , a plenum 576 integral with the anode substrate 570 , and holes 578 in fluid communication with the plenum 576 .

[0085] 5D, anode substrate 580 includes an anode 584, a first plenum 586, and a second plenum 590. The electrolyte solution flows into first plenum 586 and fluid holes 588 and reaches the top surface of anode substrate 580. For example, fluid holes 588 can extend from first plenum 586 to a location between anodes 584.

[0086] Fluid holes 592 connect the trench 594 (or top surface) of the anode substrate 580 to the second plenum 590. For example, the fluid holes 592 can extend from the second plenum 590 to a location along the bottom surface of the trench 594. The electrolyte solution is pumped or flows into the first plenum 586 and through the fluid holes 588 to the top surface of the anode substrate 580. The electrolyte solution flows into the region between the anode 584 and the corresponding region on the workpiece substrate. The electrolyte solution eventually flows into the trench 594 and through the fluid holes 592 into the second plenum 590.

[0087] 5E, valves 596, such as microelectromechanical valves, can be disposed in one or more of the fluidic holes 588 and / or 592 to allow selective control of the delivery of electrolyte solution to various locations. In some examples, the valves 596 are controlled by the controller 160 using the wiring layer 132 described above.

[0088] 6A and 6G, an example of metal printing onto a workpiece substrate is shown. In FIG. 6A, a first set of anodes 610 (only the energized anodes are shown) are printed onto the workpiece substrate 612 at a predetermined gap g. s The electrolyte solution is placed in a predetermined gap g s 6B, metal traces 614 are deposited on the workpiece substrate 612 in the area surrounding the first set of powered anodes 610, and then the first set of anodes 610 are de-energized (shown by the dotted lines).

[0089] In FIG. 6C, the anode substrate is moved laterally relative to the workpiece substrate (the anode substrate is moved to a predetermined gap g of the workpiece substrate 612). s The electrolyte solution is placed in a predetermined gap g s (a predetermined gap g of the workpiece substrate 612) s6D , metal traces 624 are deposited on the workpiece substrate 612 in the area surrounding the second set of powered anodes 620, and then the second set of anodes 620 are de-energized (shown by the dotted lines).

[0090] In Figure 6E, the anode substrate is moved laterally and downwardly relative to the workpiece substrate until the electrolyte solution reaches a predetermined gap g s (a predetermined gap g of the workpiece substrate 612) s 6F, a third set of anodes 630 (disposed within the workpiece substrate 612) is energized. In FIG. 6F, metal traces 634 are deposited on the workpiece substrate 612 in the area surrounding the third set of anodes 630, and then the third set of anodes 630 is de-energized (shown by the dotted lines).

[0091] 6G shows the completed metal trace 650. After the metal trace is printed, a mask layer is deposited and patterned. Etching is performed to remove the metal seed layer in areas where the metal trace will not be printed, and then the mask layer is removed.

[0092] Referring now to Figures 7 and 8, the location and number of inlets and / or outlets can be varied. In Figure 7, adding additional locations for inlet / outlet fluid ports and manifolds (e.g., one, two, three, four, or more) allows for the use of combinations of inlet and outlet ports. Valves can be used to cycle different trajectories of the fluid paths over time. For example, Figure 7 shows an anode 710 with four fluid ports 714-1, 714-2, 714-3, and 714-4 surrounding the anode 710.

[0093] In one method of operation, the valve is configured to allow fluid flow from fluid hole 714-1 out of fluid hole 714-3 for a first predetermined period. Then, fluid flows from fluid hole 714-2 out of fluid hole 714-4 for a second predetermined period. Then, fluid flows from fluid hole 714-1 out of fluid hole 714-3 for a first predetermined period. Then, fluid flows from fluid hole 714-4 out of fluid hole 714-2 for a third predetermined period. Alternatively, fluid can simultaneously enter the gap from fluid holes 714-1 and 714-3 and exit from fluid holes 714-2 and 714-4, after which the fluid flow direction reverses. Thus, when multiple manifolds are present, the flow direction and flow pattern can be modified to provide a more time-averaged uniform flow direction.

[0094] 8, groups of anodes 812-1, 812-2, 812-3, and 812-4 (in this example, each group includes four anodes) surround central fluid holes 828-1, 828-2, 828-3, and 828-4, respectively. Fluid holes 820 and 822 surround the groups of anodes 812-1, 812-2, 812-3, and 812-4. In some examples, central fluid holes 828-1, 828-2, 828-3, and 828-4 have larger diameters than the sets of fluid holes 820 and 822.

[0095] Fluid holes 820 and 822 are connected to one fluid supply and return manifold, and hole 828 is connected to another fluid supply and return manifold. The dotted lines in Figure 8 indicate that a flow symmetry boundary for this configuration surrounds each group and defines a flow unit cell.

[0096] The sets of fluid holes 820 and 822 include two types: fluid holes 822 located at the edges of the symmetric boundary, and fluid holes 822 located at the corners. In some examples, half of the fluid holes 822 enter and exit a corresponding one of the central fluid holes 828. The other half of the fluid holes 822 enter and exit a different one of the central fluid holes 828.

[0097] Corner fluid holes 820 supply or remove one-quarter of their fluid to nearby centrally located holes 828. As previously mentioned, flow can flow in or out of the centrally located holes between peripheral flow element types. The flow holes 822 can also be fed by four unique, separately controllable flow manifolds. Other arrangements of holes and number of distribution manifolds can be used to create multiple different flow direction and path possibilities within the gap and across the surface, allowing for randomization of patterns by using different sets over time and reversing the flow pattern.

[0098] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the present disclosure can be embodied in a variety of forms. Accordingly, while the present disclosure includes specific examples, the true scope of the disclosure should not be limited to such examples, as other modifications will become apparent upon review of the drawings, the specification, and the following claims. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without altering the principles of the disclosure. Furthermore, although each embodiment is described above as having specific features, any one or more of these features described with respect to any embodiment of the present disclosure may be implemented in other embodiments and / or combined with any features of the other embodiments (even if such combination is not explicitly described). In other words, the described embodiments are not mutually exclusive, and substituting one or more embodiments for one another is within the scope of the present disclosure.

[0099] Spatial and functional relationships between elements (e.g., modules, circuit elements, semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Also, when a relationship between a first element and a second element is described in the above disclosure, unless expressly described as "direct," the relationship may be a direct relationship where no other intervening elements exist between the first element and the second element, or an indirect relationship where one or more intervening elements (spatial or functional) exist between the first element and the second element. As used herein, the phrase "at least one of A, B, and C" should be interpreted in the sense of a logical (A or B or C) using a non-exclusive logical OR, and not in the sense of "at least one of A, at least one of B, and at least one of C."

[0100] In some embodiments, the controller is part of a system, and such a system may be part of the examples described above. Such systems may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (e.g., wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling system operation before, during, and after semiconductor wafer or substrate processing. Such electronics may be referred to as a "controller" and may control various components or subcomponents of one or more systems. The controller may be programmed to control any of the processes disclosed herein, depending on the processing requirements and / or type of system. Such processes may include process gas delivery, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, wafer transfer to and from the tool, and wafer transfer to and from other transfer tools and / or load locks connected or interfaced with the particular system.

[0101] Broadly, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors, i.e., microcontrollers, that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. The operational parameters, in some embodiments, may be part of a recipe defined by a process engineer to implement one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0102] In some embodiments, the controller may be part of, coupled to, or a combination of a computer integrated with, coupled to, or otherwise networked to the system. For example, the controller may be in the “cloud” or all or part of a fab host computer system. This allows for remote access of wafer processing. The computer may provide remote access to the system to monitor the current progress of a fabrication operation, review the history of past fabrication operations, review trends or performance criteria from multiple fabrication operations, modify parameters of a current process, configure processing steps following a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to the system over a network. Such a network may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data. Such data identifies parameters for each processing step performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool the controller is configured to interface with or control. Thus, as discussed above, the controller may be distributed, for example, by having one or more individual controllers networked together and working together toward a common purpose (such as the processes and controls described herein). An example of a distributed controller for such purposes would include one or more integrated circuits on the chamber in communication with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer) and coupled to control the process in the chamber.

[0103] Exemplary systems may include, but are not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a tracking chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0104] As described above, depending on the process step or steps being performed by the tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to and from tool locations and / or load ports in a semiconductor fabrication factory.

Claims

1. 1. A system for printing metal traces on a substrate, comprising: an anode substrate; a plurality of anodes disposed on one side of the anode substrate, the anodes having a first predetermined gap between adjacent anodes of the plurality of anodes; a first plurality of fluid holes having one end located between the plurality of anodes; a plurality of control devices configured to selectively supply current to the plurality of anodes, respectively; the anode substrate is positioned within a second predetermined gap of a workpiece substrate including a metal seed layer; The ratio of the second predetermined gap to the first predetermined gap is in the range of 0.5:1 to 1.5:

1. a plurality of control devices; an array controller configured to energize selected anodes of the plurality of anodes using corresponding control devices of the plurality of control devices while an electrolyte solution is supplied through the first plurality of fluid holes between the anode substrate and the workpiece substrate; A system comprising:

2. 10. The system of claim 1, The system wherein the plurality of anodes comprises inert anodes and the electrolyte solution comprises metal cations.

3. 10. The system of claim 1, The anode substrate further includes a second plurality of fluid holes positioned between the plurality of anodes for removing the electrolyte solution between the anode substrate and the workpiece substrate.

4. 10. The system of claim 1, The system further comprising an electrolyte source, the anode substrate including a plenum in fluid communication with the electrolyte source.

5. 10. The system of claim 1, The system further comprises a manifold disposed adjacent to the anode substrate, the manifold including an inlet in fluid communication with an electrolyte source and an outlet in fluid communication with the first plurality of fluid holes.

6. 10. The system of claim 1, 10. The system of claim 9, further comprising a plurality of valves respectively disposed in the first plurality of fluid holes, the plurality of valves configured to selectively control flow of electrolyte solution within the first plurality of fluid holes.

7. 7. The system of claim 6, The system, wherein the array controller is configured to control the valves.

8. 10. The system of claim 1, The system further comprises a positioning device configured to adjust the position of at least one of the workpiece substrate and the anode substrate.

9. 9. The system of claim 8, The system, wherein the positioning device moves the at least one of the workpiece substrate and the anode substrate during printing of the metal traces.

10. 9. The system of claim 8, The array controller a) printing a first metal trace onto the workpiece substrate; b) causing the positioning device to move the workpiece substrate relative to the anode substrate by the second predetermined gap in at least one of a lateral and vertical direction; c) printing a second metal trace onto the workpiece substrate; The system is configured as follows:

11. 11. The system of claim 10, The array controller is configured to repeat b) and c) one or more times.

12. 10. The system of claim 1, The system, wherein the first predetermined gap is in the range of 0.1 micrometers to 100 micrometers.

13. 10. The system of claim 1, The system, wherein the first predetermined gap is in the range of 0.5 micrometers to 10 micrometers.

14. 7. The system of claim 6, a plurality of valves respectively associated with the plurality of fluid ports; Furthermore, the array controller is configured to control the valves to adjust at least one of a direction and a pattern of fluid flow from the plurality of fluid holes disposed adjacent each of the plurality of anodes. system.

15. 10. The system of claim 1, The system wherein the plurality of control devices are selected from the group consisting of switches and fuses.

16. 1. A method for printing metal traces on a substrate, comprising: providing a workpiece substrate including one or more underlayers, a barrier / adhesion layer, and a seed layer; providing an anode substrate including a plurality of anodes disposed on one side of the substrate and a first plurality of holes having edges between the plurality of anodes, the plurality of anodes being spaced apart from adjacent ones of the plurality of anodes by a first predetermined gap; placing the anode substrate within a second predetermined gap of a workpiece substrate including a metal seed layer, wherein a ratio of the second predetermined gap to the first predetermined gap is in a range of 0.5:1 to 1.5:1; energizing selected anodes of the plurality of anodes while an electrolyte solution is supplied through the first plurality of holes between the anode substrate and the workpiece substrate; A method comprising:

17. 17. The method of claim 16, The method, wherein the plurality of anodes comprises inert anodes.

18. 17. The method of claim 16, The method further includes disposing a second plurality of fluid holes between the plurality of anodes to remove the electrolyte solution from between the anode substrate and the workpiece substrate.

19. 17. The method of claim 16, The method further comprises supplying an electrolyte solution to a plenum within the anode substrate.

20. 17. The method of claim 16, The method further comprising attaching a manifold to the anode substrate with an outlet of the manifold in fluid communication with the first plurality of fluid holes.

21. 17. The method of claim 16, The method further comprising controlling flow in the first plurality of fluid holes using a plurality of valves.

22. 17. The method of claim 16, The method further includes adjusting the position of at least one of the workpiece substrate and the anode substrate after energizing the selected anode of the plurality of anodes.

23. 23. The method of claim 22, a) printing a first metal trace onto the workpiece substrate; b) moving the workpiece substrate relative to the anode substrate in at least one of a lateral and vertical direction; c) printing a second metal trace onto the workpiece substrate; The method further comprises:

24. 24. The method of claim 23, The method further comprising repeating b) and c) one or more times.

25. 17. The method of claim 16, The method, wherein the first predetermined gap is in the range of 0.1 micrometers to 100 micrometers.

26. 17. The method of claim 16, The method, wherein the first predetermined gap is in the range of 0.5 micrometers to 10 micrometers.

27. 18. The method of claim 17, controlling fluid flow within the first plurality of fluid holes using a respective plurality of valves; controlling the valves to adjust at least one of a direction and a pattern of fluid flow from the first plurality of fluid holes disposed adjacent each of the plurality of anodes; The method further comprises:

28. 17. The method of claim 16, The method further includes adjusting the position of at least one of the workpiece substrate and the anode substrate during printing of the metal traces.

29. 1. A method for printing metal traces on a substrate, comprising: providing a workpiece substrate including one or more underlayers, a barrier / adhesion layer, and a seed layer; providing an anode substrate including a plurality of anodes disposed on one side of the substrate, the plurality of anodes being spaced apart from adjacent ones of the plurality of anodes by a first predetermined gap; placing the anode substrate within a second predetermined gap of a workpiece substrate including a metal seed layer, wherein a ratio of the second predetermined gap to the first predetermined gap is in a range of 0.5:1 to 1.5:1; energizing selected anodes of the plurality of anodes while an electrolyte solution is supplied between the anode substrate and the workpiece substrate; separating the anode substrate and the workpiece substrate; placing the anode substrate within the second predetermined gap of the workpiece substrate; energizing selected anodes of the plurality of anodes while the electrolyte solution is supplied between the anode substrate and the workpiece substrate; A method comprising:

30. 30. The method of claim 29, The method further comprises agitating the electrolyte solution after separating the anode substrate and the workpiece substrate.

31. 30. The method of claim 29, The method further includes, after agitating the electrolyte solution, placing the anode substrate within the second predetermined gap of the workpiece substrate.

32. 30. The method of claim 29, The method, wherein the plurality of anodes comprises inert anodes.

33. 30. The method of claim 29, The method further includes providing an electrolyte solution between the edges of the anode substrate and the workpiece substrate.

34. 30. The method of claim 29, The method further includes adjusting the position of at least one of the workpiece substrate and the anode substrate.

35. 35. The method of claim 34, a) printing a first metal trace onto the workpiece substrate; b) moving the workpiece substrate relative to the anode substrate in at least one of a lateral and vertical direction; c) printing a second metal trace onto the workpiece substrate; The method further comprises:

36. 36. The method of claim 35, The method further comprising repeating b) and c) one or more times.

37. 30. The method of claim 29, The method, wherein the first predetermined gap is in the range of 0.1 micrometers to 100 micrometers.

38. 30. The method of claim 29, The method, wherein the first predetermined gap is in the range of 0.5 micrometers to 10 micrometers.

39. 30. The method of claim 29, The method further includes adjusting the position of at least one of the workpiece substrate and the anode substrate during printing of the metal traces.

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