ELECTROSTATIC END EFFECTOR FOR MANUFACTURING SYSTEM ROBOT

Disclosed herein are embodiments of an electrostatic end effector, and methods of manufacturing the same. In one embodiment, an electrostatic end effector comprises a ceramic base, a first electrode layer coupled to the ceramic base, and a second electrode layer coupled to the ceramic base. The electrostatic end effector is configured to generate an electrostatic force upon a substrate responsive to a voltage applied to the first electrode. The electrostatic force upon the substrate may increase the friction force upon the substrate which may allow the end effector to accelerate at faster rates than current technologies allow without the substrate slipping on the end effector.

TECHNICAL FIELD

Embodiments of the present disclosure relate, in general, to methods of manufacture and design parameters for an electrostatic end effector for a semiconductor manufacturing system robot.

BACKGROUND

An electronic device manufacturing system may include one or more tools or components for transporting and manufacturing substrates. An electronic device manufacturing system may employ a robot apparatus (e.g., a transfer chamber robot, a factory interface robot) to transfer substrates from one location to another. For example, the transfer chamber robot may be configured to transport substrates between a load lock and the process chambers. The robot apparatus may have one or more end effectors which handle the substrates as the substrates are transferred between locations.

Some current robot end effectors rely on static friction between the end effector and the substrate to enable transportation of the substrate on the end effector by the robot. Thus, the robot is limited in its peak end effector acceleration to approximately 0.1G (a tenth of the acceleration of gravity). If the end effector accelerates beyond the limit allowed by the force of static friction between the end effector and the substrate, the substrate may slide on the end effector, compromising substrate placement and manufacturing processes. Even a small amount of substrate displacement may cause particles to be scraped off the substrate, leading to contamination. Accordingly, improved end effectors for transporting substrates with increased speed efficiency are sought.

SUMMARY

In an aspect of the disclosure, an electrostatic end effector includes a ceramic base, a first electrode layer coupled to the ceramic base, and a second electrode layer coupled to the ceramic base. The electrostatic end effector is configured to generate an electrostatic force upon a substrate responsive to a voltage applied to the first electrode.

In another aspect of the disclosure, a method of manufacturing an electrostatic end effector includes providing a ceramic blank. The method further includes performing a material removal process on the ceramic blank to generate one or more features on a top surface of the ceramic blank. The method further includes depositing a cathode layer onto at least a top surface of the ceramic blank. The method further includes depositing a dielectric layer on top of at least the cathode layer. The method further includes depositing an anode layer on top of at least a portion of the dielectric layer.

In another aspect of the disclosure, a method of manufacturing an electrostatic end effector includes providing a plurality of ceramic sheets. The method further includes generating a set of laminated layers by performing a lamination process to combine one or more electrode layers with the plurality of ceramic sheets. The method further includes generating a set of sintered layer by performing a sintering process to combine the laminated layers. The method further includes grinding at least a top surface of the sintered layers. The method further includes polishing at least the top surface of the sintered layers.

DETAILED DESCRIPTION OF EMBODIMENTS

Described herein are technologies directed to an electrostatic robot end effector configured to transfer substrates in an electronic device manufacturing system. An electronic device manufacturing system may perform one or more processes upon a substrate in one or more process chambers. An electronic device manufacturing system may include a transfer chamber positioned proximate to the one or more process chambers. The transfer chamber may include a robot having one or more end effectors upon which a substrate may be positioned whilst the substrate is transferred between one or more process chambers by the robot. Additionally, an electronic device manufacturing system may include a factory interface robot proximate to a factory interface. The factory interface robot may include a robot having one or more end effectors upon which a substrate may be positioned whilst the substrate is transferred from or to the factory interface. Existing robot end effectors rely on static friction between the end effector and the substrate to enable transportation of the substrate, thus limiting the acceleration of the end effector. Accelerating the end effector beyond the static friction limit may compromise substrate placement and cause contamination from scraped off particles, which may result in defective and unusable substrates.

Embodiments of the present disclosure are directed to an electrostatic end effector for a semiconductor manufacturing system robot. In some embodiments, the robot end effector described herein may include an anode and a cathode. The anode and the cathode may be substantially coplanar. For example, the anode and cathode may be disposed substantially within the same plane. Additionally, the anode and the cathode may be separated by one or more dielectric layers. When a substrate is positioned on the end effector, a voltage may be applied to the cathode. The anode may be grounded. In some embodiments, the applied voltage may be monopolar, but may be bipolar in other embodiments. The applied voltage may create an attractive electrostatic force between the end effector and the substrate. The attractive force may increase the static friction between the end effector and the substrate, allowing the end effector to accelerate at faster rates than end effectors relying solely on static friction while transferring the substrate without the substrate slipping.

A first method of manufacturing the robot end effector of the present disclosure may include providing a ceramic blank. In some embodiments, the ceramic blank is machined from stock. The ceramic blank may be machined from alumina (i.e., aluminum oxide), one or more other ceramic materials of suitable characteristics, or any combination thereof. The ceramic blank may have a flat top surface. The method may further include material removal operations on at least the top surface of the ceramic blank in controlled locations. In some embodiments, the ceramic blank is micro-bead blasted. The material removal process may generate multiple pillars and valleys upon the top surface of the end effector. The multiple pillars may be small, substantially cylindrical protrusions protruding from the top surface of the end effector. The multiple pillars may be arranged in a pattern on the top surface of the end effector. In some embodiments, the multiple pillars are substantially arranged in rows on the top surface of the end effector. The one or more valleys may be depressions in the top surface of the end effector. The one or more valleys may be longer than they are wide. In some embodiments, the one or more valleys separate one or more rows of pillars. One or more layers may then be deposited on at least the top surface of the end effector. In some embodiments, the one or more layers are deposited via a physical vapor deposition process (PVD). A first layer deposited upon a top surface of the end effector may be a cathode layer. A second layer may be a dielectric layer. A third layer may be an anode layer. In some embodiments, the anode layer may be a ground layer. The anode layer may be deposited upon at least the tops of the pillars, on top of the dielectric layer. When in use, the substrate may be positioned on the anode layer on the top of the pillars. In some embodiments, each of the one or more layers may be approximately 10 µm. However, a range of layer thicknesses may be used to construct the end effector in a manner that will provide a sufficient attractive electrostatic force between the end effector and the substrate.

A second method of manufacturing the electrostatic end effector of the present disclosure may include first machining multiple ceramic sheets. In some embodiments, the ceramic sheets are fabricated from alumina. One or more electrode layers may be combined with the multiple ceramic sheets using a lamination process. In some embodiments, the end effector includes a first electrode layer and a second electrode layer which are coplanar and electrically insulated from one another. In other embodiments, the end effector includes a first electrode layer disposed below a second electrode layer. The one or more electrode layers may be comprised of a conductive material. For example, the one or more electrode layers may be platinum. The method may further include generating a set of sintered layers by performing a sintering process to combine the laminated layers into a rough end effector. The sintering process may include heating the laminated layers sufficiently so that the layers coalesce into a single mass. The method may further include grinding the top surface of the end effector to flatten said surface. The method may further include polishing the top surface of the end effector. In some embodiments, the polishing is may be performed by a lapping process. In some embodiments, the lapping process is a polishing process. For example, a lapping process may be achieved by rubbing a tool surface against the top surface of the end effector with fine abrasives in between. The lapping process may include using a fine abrasive on the top surface of the end effector to further flatten and polish said surface. When in operation, a substrate may be positioned upon the top surface of the end effector. A voltage may be applied to the second electrode layer, whilst the first electrode layer is grounded. This may generate an electrostatic force between the end effector and the substrate, causing an increase in static friction between the substrate and the end effector.

In some embodiments, the second method of manufacturing further includes a material removal operation performed on the top surface of the end effector. In some embodiments, the material removal operation is a micro-bead blasting process. The micro-bead blasting process may include applying micro-abrasives to the top surface of the end effector at high pressure to remove material from the surface of the end effector. The micro-abrasives may be small glass beads. The material removal operation may generate multiple mesas upon the top surface of the end effector. The multiple mesas may be substantially cylindrical protrusions which protrude from the top surface of the end effector. In some embodiments, a protruded electrode may rise from one or more of the mesas and extend down to the first, lower electrode layer. The one or more protruding electrodes may be electrically connected to the lower electrode layer while being electrically insulated from the upper electrode layer. The one or more protruding electrodes may be made of a conductive material. For example, the one or more protruding electrodes may be made of platinum. When the end effector is in operation, a substrate may be positioned upon the one or more protruding electrodes.

An end effector which applies an attractive force between the end effector and the substrate could allow for an increased acceleration limit of the end effector without the substrate becoming displaced. This in turn could enable increased substrate transfer speeds leading to higher productivity of the manufacturing system

FIG.1is a top schematic view of an example manufacturing system100, according to aspects of the present disclosure. Manufacturing system100may perform one or more processes on a substrate102. Substrate102may be any suitably rigid, fixed-dimension, planar article, such as, e.g., a silicon-containing disc or wafer, a patterned wafer, a glass plate, or the like, suitable for fabricating electronic devices or circuit components thereon.

Manufacturing system100may include a process tool104and a factory interface106coupled to process tool104. Process tool104may include a housing108having a transfer chamber110therein. Transfer chamber110may include one or more process chambers (also referred to as processing chambers)114,116,118disposed therearound and coupled thereto. Process chambers114,116,118may be coupled to transfer chamber110through respective ports, such as slit valves or the like. Transfer chamber110may also include a transfer chamber robot112configured to transfer substrate102between process chambers114,116,118, load lock120, etc. Transfer chamber robot112may include one or multiple arms where each arm includes one or more end effectors at the end of each arm. The end effector may be configured to handle particular objects, such as wafers.

Process chambers114,116,118may be adapted to carry out any number of processes on substrates102. A same or different substrate process may take place in each processing chamber114,116,118. A substrate process may include atomic layer deposition (ALD), physical vapor deposition (PVD), chemical vapor deposition (CVD), etching, annealing, curing, pre-cleaning, metal or metal oxide removal, or the like. Other processes may be carried out on substrates therein. Process chambers114,116,118may each include one or more sensors configured to capture data for substrate102before, after, or during a substrate process. For example, the one or more sensors may be configured to capture spectral data and/or non-spectral data for a portion of substrate102during a substrate process. In other or similar embodiments, the one or more sensors may be configured to capture data associated with the environment within process chamber114,116,118before, after, or during the substrate process. For example, the one or more sensors may be configured to capture data associated with a temperature, a pressure, a gas concentration, etc. of the environment within process chamber114,116,118during the substrate process.

A load lock120may also be coupled to housing108and transfer chamber110. Load lock120may be configured to interface with, and be coupled to, transfer chamber110on one side and factory interface106. Load lock120may have an environmentally-controlled atmosphere that may be changed from a vacuum environment (wherein substrates may be transferred to and from transfer chamber110) to at or near atmospheric-pressure inert-gas environment (wherein substrates may be transferred to and from factory interface106) in some embodiments. Factory interface106may be any suitable enclosure, such as, e.g., an Equipment Front End Module (EFEM). Factory interface106may be configured to receive substrates102from substrate carriers122(e.g., Front Opening Unified Pods (FOUPs)) docked at various load ports124of factory interface106. A factory interface robot126(shown dotted) may be configured to transfer substrates302between carriers (also referred to as containers)122and load lock120. Carriers122may be a substrate storage carrier or a replacement part storage carrier.

Manufacturing system100may also be connected to a client device (not shown) that is configured to provide information regarding manufacturing system100to a user (e.g., an operator). In some embodiments, the client device may provide information to a user of manufacturing system100via one or more graphical user interfaces (GUIs). For example, the client device may provide information regarding a target thickness profile for a film to be deposited on a surface of a substrate102during a deposition process performed at a process chamber114,116,118via a GUI. The client device may also provide information regarding a modification to a process recipe in view of a respective set of deposition settings predicted to correspond to the target profile, in accordance with embodiments described herein.

Manufacturing system100may also include a system controller128. System controller128may be and/or include a computing device such as a personal computer, a server computer, a programmable logic controller (PLC), a microcontroller, and so on. System controller128may include one or more processing devices, which may be general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processing device may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, or a processor implementing other instruction sets or processors implementing a combination of instruction sets. The processing device may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. System controller128may include a data storage device (e.g., one or more disk drives and/or solid state drives), a main memory, a static memory, a network interface, and/or other components. System controller128may execute instructions to perform any one or more of the methodologies and/or embodiments described herein. In some embodiments, system controller128may execute instructions to perform one or more operations at manufacturing system100in accordance with a process recipe. The instructions may be stored on a computer readable storage medium, which may include the main memory, static memory, secondary storage and/or processing device (during execution of the instructions).

System controller128may receive data from sensors included on or within various portions of manufacturing system100(e.g., processing chambers114,116,118, transfer chamber110, load lock120, etc.). In some embodiments, data received by the system controller128may include spectral data and/or non-spectral data for a portion of substrate102. In other or similar embodiments, data received by the system controller128may include data associated with processing substrate102at processing chamber114,116,118, as described previously. For purposes of the present description, system controller128is described as receiving data from sensors included within process chambers114,116,118. However, system controller128may receive data from any portion of manufacturing system100and may use data received from the portion in accordance with embodiments described herein. In an illustrative example, system controller128may receive data from one or more sensors for process chamber114,116,118before, after, or during a substrate process at the process chamber114,116,118. Data received from sensors of the various portions of manufacturing system100may be stored in a data store150. Data store150may be included as a component within system controller128or may be a separate component from system controller128.

FIG.2Ais a schematic top view of end effector200, in accordance with embodiments of the present disclosure. End effector200may include an end effector base210, a robot connector216, pillars220, a cathode layer230, a dielectric layer240, and a ground layer250.FIG.2Ashows the layers of end effector200superimposed upon each other. The layers of end effector200are shown separately inFIGS.3A-D. In some embodiments, the end effector200may include one or more sensors.

The end effector base210may comprise a ceramic material. In some embodiments, end effector body210is alumina ceramic. End effector200may be attached to a robot via robot connector216by way of one or more fasteners or other connectors. In some embodiments, pillars220are arranged along one or more side edges of end effector body210. In some embodiments, pillars220are arranged in lines substantially parallel to a longitudinal axis of the end effector base210. In some embodiments, the pillars220rise approximately 20 µm above a surface of the end effector base210. Pillars220may support a substrate that end effector200is transferring or is to transfer. In some embodiments, end effector200includes one hundred or more pillars220. In some embodiments, end effector200includes sufficient pillars so that a substrate being carried by end effector200flexes minimally when an attractive force is applied between the end effector200and the substrate. End effector base210may include one or more valleys225substantially between one or more rows of pillars220. The one or more valleys225may have been generated by a material removal process. In some embodiments, the same process that generates the pillars220also generates the one or more valleys225. The one or more valleys225may be created by a micro-bead blasting process. In some embodiments, the one or more valleys225of the end effector base210are approximately 40 µm deep.

One or more layers may be deposited upon at least the top surface of end effector200. The one or more layers may be deposited by one or more deposition processes. In some embodiments, the one or more layers are deposited by a vapor deposition process. In certain embodiments, the one or more layers are deposited by a PVD process. The cathode layer230and the ground layer250may be made up of a conductive material. The ground layer250may be an anode layer. In some embodiments, the cathode layer230and the ground layer250are a titanium layer deposited by a PVD process. The cathode layer230may be applied in the one or more valleys of end effector base210. Dielectric layer240may be deposited on top of the cathode layer230(seeFIG.2B). Dielectric layer240may comprise a dielectric. In some embodiments, the dielectric layer240is a layer of aluminum oxide (AlO). In some embodiments, dielectric layer240may be deposited on top of the cathode layer230and the pillars220(seeFIG.2B). In some embodiments, the ground layer250is deposited on top of the dielectric layer240. In some embodiments, the ground layer250is deposited on a top surface of each of the pillars220and also forming a conductive path.

FIG.2Bis a cross-sectional schematic view of at least a portion of a monopolar electrostatic end effector, according to certain embodiments. End effector base210may have one or more layers deposited on at least the top surface. In some embodiments, cathode layer230, dielectric layer240, and ground layer250are deposited upon end effector base210. The cathode layer230, dielectric layer240, and ground layer250may be disposed within an outer border of the end effector base210, the outer border being formed by the outer edges of the end effector base210. The cathode layer230may be deposited in one or more valleys225of end effector base210. The dielectric layer240may be deposited on top of the cathode layer230and extend up a sidewall of a valley225of the end effector base210and cover at least a surface of one or more pillars220. The ground layer250may be deposited upon the dielectric layer240where the dielectric layer240covers one or more pillars220. A substrate280may be positioned on top the ground layer250. In some embodiments, each of the cathode layer230, dielectric layer240, and ground layer250are approximately 10 µm thick. In other embodiments, each of the cathode layer230, dielectric layer240, and ground layer250may be a thickness such that when a voltage is applied to the cathode layer230, a desired resultant electrostatic attractive force is applied upon the substrate280. In some embodiments, gap of approximately 60 µm exists between a top surface of the dielectric layer240and a bottom surface of the substrate280. However, a smaller or larger gap may exist if an appropriate voltage is applied to the cathode layer230in order to create a desired resultant attractive electrostatic force. In some embodiments, the gap may be necessary to avoid glow discharge failures for particular environments or pressure ranges. Additionally, the gap may be tailored for a specific pressure range (e.g., smaller gap for a certain pressure, larger gap for a different pressure). In some embodiments, the gap is adjusted by the use of Piezo-Electric actuators causing the pillars to extend and/or retract vertically.

In some embodiments, end effector200may be used by a transfer chamber robot or a factory interface robot to transfer substrate in an electronic device manufacturing system (e.g., system100). A substrate280may be transported by the end effector200. While the end effector200is transporting the substrate280, the substrate280may be positioned on top of ground layer250. A voltage may be applied to the cathode layer230, and the ground layer250may be grounded, thus creating an electrostatic force between the end effector200and the substrate280. In some embodiments, the voltage applied to the cathode layer230is approximately 500 volts, but the voltage applied may be any required voltage to create the desired electrostatic force. The electrostatic force may act upon the substrate280so as to reduce or eliminate any slipping of the substrate280on the end effector200when the end effector200is under an acceleration condition. This electrostatic force thus allows for greater acceleration of the end effector200without the substrate280slipping.

FIGS.3A-Dshow a top representation of one or more layers of a monopolar electrostatic end effector, according to certain embodiments. In some embodiments, the end effector base210includes pillars220and one or more valleys225substantially between the pillars. The cathode layer230may be deposited on the top surface of the end effector base210within the outer border of the end effector base210. The dielectric layer240may be deposited on top of at least the cathode layer230and a top surface of the end effector base210. The ground layer250may be deposited on top of at least the dielectric layer240and a top surface of the end effector base210. The ground layer250may be deposited on the tops of the pillars220and may create a conductive path between each of the pillars220.

FIG.4Ais a top schematic cutaway view of a monopolar electrostatic end effector, according to certain embodiments. In some embodiments, end effector400includes an end effector base410. Multiple mesas420may be distributed about a top surface of the end effector base410. In some embodiments, each of the mesas is approximately 10 µm tall. The end effector400may include one or more layers imbedded between one or more laminated sheets. The one or more laminated sheets may be a ceramic sheet. In some embodiments, the one or more embedded layers are coplanar. In other embodiments, the one or more layers are not coplanar. In some embodiments, the one or more laminated sheets are sheets of alumina. End effector400may include a cathode layer430between one or more laminated sheets disposed within an outer border of the end effector base410formed by the outer edges of the end effector base410. The cathode layer430may comprise a conductive material. In some embodiments, the cathode layer430is a platinum layer. End effector400may also include a ground layer450between one or more laminated sheets. The ground layer450may comprise a conductive material. In some embodiments, the ground layer450is a platinum layer. In certain embodiments, the cathode layer430and the ground layer450are coplanar, but are electrically insulated from each other. In some embodiments, the cathode layer430and the ground layer450reside on different planes within the end effector body410.

FIG.4Bis a bottom schematic cutaway view of a monopolar electrostatic end effector, according to certain embodiments. End effector400may include the ground layer450. The ground layer450may be embedded between one or more ceramic sheets and disposed within an outer border of the end effector base410. In some embodiments, the ground layer450includes one or more traces which run within the end effector base410. In other embodiments, the ground layer450is disposed over substantially an entire footprint of the end effector base410. In certain embodiments, the ground layer450connects one or more ground pins460. In certain embodiments, end effector400may have as few as three ground pins460. In other embodiments, end effector400has five ground pins460. (SeeFIG.4Cfor an explanation of the ground pins460).

FIG.4Cis a cross-sectional schematic view of at least a portion of a monopolar electrostatic end effector, according to certain embodiments. In some embodiments, the ground layer450is disposed within the end effector base410beneath the cathode layer430. The cathode layer430and the ground layer450are electrically insulated from one another.

End effector400may include multiple mesas420on a top surface of the end effector base410. A ground pin460may include a mesa420and one or more ground protrusions452. Each ground protrusion452may comprise a conductive material. For example, in some embodiments, each ground protrusion452is platinum. Ground protrusions452may rise above a top surface of mesa420. In some embodiments, ground protrusions452rise two to three µm above a top surface of mesa420.

In some embodiments, end effector400may be used by a transfer chamber robot or factory interface robot to transfer substrates in an electronic device manufacturing system. A substrate may be transported by the end effector400. While the end effector400is transporting the substrate, the substrate sits on top of one or more mesas420. A specific gap may exist between the bottom of the substrate and the cathode layer (e.g., 70 µm). The gap may be tailored for a specific pressure. In some embodiments, the gap may be adjusted by the use of Piezo-Electric actuators to vertically extend and/or retract the mesas420. The substrate may make electrical contact with the one or more ground protrusions. A voltage may be applied to the cathode layer430, while the ground layer450is grounded, thus creating an electrostatic force between the end effector400and the substrate. In some embodiments, the voltage applied to the cathode layer430is 500 volts, but the voltage applied may be any required voltage to create the desired electrostatic force. The electrostatic force may act upon the substrate so as to reduce or eliminate any slipping of the substrate on the end effector400when the end effector400is under an acceleration condition. This electrostatic force thus allows for greater acceleration of the end effector400without the substrate slipping.

FIG.5is a flow chart for a method for manufacturing a monopolar electrostatic end effector, according to certain embodiments. Method500is performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computer system or a dedicated machine), firmware, or some combination thereof. In one implementation, method500may be performed by a computer system or a processing device not depicted in the figures. In other or similar implementations, one or more operations of method500may be performed by one or more other machines not depicted in the figures.

At operation510, a ceramic blank is provided. In some embodiments, the ceramic blank is machined. In some embodiments, the ceramic blank has at least the approximate shape of an electrostatic end effector. In certain embodiments, the ceramic blank is of alumina.

At operation520, the ceramic blank is subject to a material removal process to generate one or more features on the top surface of the ceramic blank. In some embodiments, the material removal process may comprise micro-bead blasting, or any another suitable material removal process capable of generating the top surface features on the ceramic blank. The material removal process may result in portions of the top surface of the ceramic blank being removed so that the work piece comprises multiple pillars and one or more valleys on a top surface of the end effector.

At operation530, a cathode layer is deposited upon at least the top surface of the end effector by a deposition process. In some embodiments, the deposition process is a vapor deposition process. The cathode layer may be deposited on the surface of at least the one or more valleys of the end effector.

At operation540, a dielectric layer may be deposited over a top surface of the end effector by a deposition process. The dielectric layer may cover the cathode layer.

At operation550, an anode layer is deposited on the end effector. The anode lay may cover a portion of the dielectric layer. In some embodiments, the anode layer is deposited over the multiple pillars of the end effector.

FIG.6is a flow chart for another method for manufacturing a monopolar electrostatic end effector, according to certain embodiments. Method600is performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computer system or a dedicated machine), firmware, or some combination thereof. In one implementation, method600may be performed by a computer system or a processing device not depicted in the figures. In other or similar implementations, one or more operations of method600may be performed by one or more other machines not depicted in the figures.

At operation610, multiple ceramic sheets are provided, each ceramic sheet having an approximate outline of the finished end effector. In certain embodiments, the ceramic sheets are sheets of alumina. In some embodiments, the ceramic sheets are machined from stock.

At operation620, a set of laminated layers are generated by performing a lamination process to combine one or more electrode layers with multiple ceramic. The one or more electrode layers may include at least an anode layer and a cathode layer. In some embodiments, the cathode layer and the anode layer are coplanar. In other embodiments, the cathode layer and the anode layer are disposed one above the other or vice versa.

At operation630, a set of sintered layers is generated by performing a sintering process to combine the laminated layers. The sintering process may include exposing the laminated layers to a sufficiently high temperature in an oven so that the layers coalesce into a single mass.

At operation640, a grinding operation may be performed on at least the top surface of the sintered end effector. The grinding operation may be accomplished using coarse abrasives. The grinding operation may leave the end effector with a roughly flat top surface.

At operation650, the at least the top surface of the end effector may be polished by a polishing process. The polishing process may be accomplished using fine abrasives. As a result of the polishing process, the end effector may have a polished smooth top surface.