KR20240137080A - Surging flow for bubble removal in electroplating systems - Google Patents

Abstract

Exemplary semiconductor processing methods can include performing an electroplating operation on a semiconductor substrate in an electroplating bath within a vessel of an electroplating system. The methods can include removing the semiconductor substrate from the electroplating bath. The methods can include closing a valve associated with a first discharge from the electroplating system. The methods can include increasing a flow from the electroplating system to a second discharge. The second discharge can be associated with a discharge channel from the vessel of the electroplating system.

Description

Surging flow for bubble removal in electroplating systems

Cross-reference to related applications

This application claims priority to and the benefit of U.S. Non-Provisional Application No. 63/303,154, filed January 26, 2022, entitled “SURGING FLOW FOR BUBBLE CLEARING IN ELECTROPLATING SYSTEMS,” the contents of which are incorporated herein by reference in their entirety for all purposes.

The present technology relates to electroplating operations in semiconductor processing. More specifically, the present technology relates to systems and methods for performing bubble removal and erasure for electroplating systems.

Integrated circuits are made possible by processes that create intricately patterned layers of material on substrate surfaces. After formation, etching, and other processing on the substrate, metals or other conductive materials are often deposited or formed to provide electrical connections between components. Because this metallization may be performed after many fabrication operations, problems encountered during metallization can result in expensive scrap substrates or wafers.

Electroplating is performed in an electroplating chamber with the device side of the wafer in a bath of liquid electrolyte and electrical contacts on the contact rings in contact with a conductive layer on the surface of the wafer. Current passes through the electrolyte and the conductive layer. Metal ions in the electrolyte are plated onto the wafer, creating a metal layer on the wafer. Air or other bubbles along the surface of the electroplating bath fluid can prevent plating at locations where the bubbles interfere with fluid contact with the substrate surface. The bubbles can form along the surface of the plating bath from any number of sources during the plating process.

Accordingly, there is a need for improved systems and methods that can be used to produce high quality devices and structures while protecting both the substrate and the plating baths. These and other needs are addressed by the present technology.

Exemplary semiconductor processing methods can include performing an electroplating operation on a semiconductor substrate in an electroplating bath within a vessel of an electroplating system. The methods can include removing the semiconductor substrate from the electroplating bath. The methods can include closing a valve associated with a first discharge from the electroplating system. The methods can include increasing a flow from the electroplating system to a second discharge. The second discharge can be associated with a discharge channel from the vessel of the electroplating system.

In some embodiments, the vessel may include a weir around the vessel, and increasing flow to the second outlet may increase flow beyond the weir into an outlet channel providing access to the second outlet. The weir may define a plurality of notches extending from an upper surface of the weir. The vessel may include an upper cup, and the upper cup may define a plurality of channels through an upper surface of the upper cup. One or more apertures may associate each of the plurality of channels with a volume within the vessel in fluid contact with the membrane. A cathode solution may be flowed within the volume. The volume may be in contact with a first surface of the membrane. The methods may include flowing the anolyte into contact with a second surface of the membrane opposite the first surface of the membrane. The first outlet may be associated with one or more outlets of the volume within the vessel. A central channel may be defined through the upper cup. The cathode solution can be flowed into the vessel through the upper cup. During the electroplating operation, the cathode solution flow can extend into each of the plurality of channels as well as over a weir extending around the vessel. The electroplating system can include a return pump fluidly coupled with the second discharge port. The electroplating system can include a level sensor disposed within the discharge channel. The level sensor can be communicatively coupled to the return pump. The return pump can be operable to increase the flow rate from the second discharge port in response to a signal from the level sensor indicating an increase in the level of cathode solution within the discharge channel.

Some embodiments of the present technology may include semiconductor processing methods. The methods may include performing an electroplating operation on a semiconductor substrate in an electroplating bath within a vessel of an electroplating system. The methods may include removing the semiconductor substrate from the electroplating bath. The methods may include diverting flow from the electroplating system to a first outlet. The methods may include increasing flow from the electroplating system to a second outlet. The second outlet may be associated with an outlet channel from the vessel of the electroplating system. Increasing flow to the second outlet may occur during a first time period. The methods may include decreasing flow from the electroplating system to the second outlet after the first time period.

In some embodiments, while decreasing the flow to the second outlet after the first time period, the methods can include increasing the flow to the first outlet. The vessel can include a weir around the vessel. Increasing the flow to the second outlet can increase the flow beyond the weir into an outlet channel that provides access to the second outlet. The weir can define a plurality of notches extending from an upper surface of the weir. The vessel can include an upper cup, the upper cup defining a plurality of channels through an upper surface of the upper cup. One or more apertures can couple each of the plurality of channels to a volume within the vessel that is in fluid contact with the membrane. A central channel can be defined through the upper cup. The cathode can flow into the vessel through the upper cup. During the electroplating operation, the cathode flow can extend beyond the weir as well as into each of the plurality of channels. While increasing the flow to the second discharge port, the height of the cathode solution can increase within the discharge channel by less than about 2 cm. The first time period can be less than about 30 seconds.

Some embodiments of the present technology may include semiconductor processing methods, including: The methods may include performing an electroplating operation on a semiconductor substrate in an electroplating bath within a vessel of an electroplating system. The vessel may include a weir surrounding the vessel. The methods may include removing the semiconductor substrate from the electroplating bath. The methods may include providing a first flow through the electroplating system through a central channel through the vessel. The methods may include providing a second flow through the electroplating system through secondary channels through the vessel and radially outwardly of the central channel. The first flow and the second flow may extend from the vessel of the electroplating system to a discharge channel. The flow to the discharge channel may extend beyond the weir into the discharge channel, which may provide access to the discharge. In some embodiments, the weir may define a plurality of notches extending from an upper surface of the weir. While increasing the flow to the second discharge, the height of the cathode solution within the discharge channel may increase by about 2 cm or less.

Such a technique can provide many advantages over prior art techniques. For example, the present technique can reduce or limit bubbles along the meniscus of the plating bath during electroplating processes. Additionally, the systems can also limit retrofit components or costs associated with improved erasing capability while erasing bubbles with minimal time loss between subsequent plating operations. These and other embodiments, along with many of their advantages and features, are described in more detail in the following description and accompanying drawings.

A further understanding of the properties and advantages of the disclosed embodiments may be realized by reference to the remaining portions of this specification and the drawings.
FIG. 1 illustrates a schematic diagram of an electroplating treatment system according to some embodiments of the present technology.
FIG. 2 illustrates a cross-sectional view of a portion of an electroplating processing system according to some embodiments of the present technology.
FIG. 3 illustrates exemplary operations of a method of operating an electroplating system according to some embodiments of the present technology.
FIG. 4 illustrates a schematic cross-sectional view of a portion of an electroplating processing system according to some embodiments of the present technology.
FIG. 5 illustrates a schematic perspective view of a slotted weir according to some embodiments of the present technology.
FIG. 6 illustrates exemplary operations of a method of operating an electroplating system according to some embodiments of the present technology.
Some of the drawings are included as schematic drawings. It should be understood that the drawings are for illustrative purposes and should not be considered to be to scale unless specifically stated to be to scale. Additionally, as schematic drawings, the drawings are provided to aid understanding and may not include all aspects or information as compared to a realistic representation, and may include exaggerated material for illustrative purposes.
In the drawings, similar components and/or features may have the same numeric reference label. Additionally, different components of the same type may be distinguished by a letter following the reference label that distinguishes between the similar components and/or features. When only a first numeric reference label is used in this specification, the description is applicable to any of the similar components and/or features having the same first numeric reference label, regardless of the letter suffix.

A variety of operations are performed in semiconductor manufacturing and processing to create vast arrays of features across a substrate. As layers of semiconductors are formed, vias, trenches, and other passages are created within the structure. These features can then be filled with a conductive or metallic material that allows electricity to be conducted from layer to layer through the device.

Electroplating operations can be performed to provide conductive material into vias and other features on a substrate. Electroplating utilizes an electrolyte bath containing ions of the conductive material to electrochemically deposit the conductive material onto the substrate and into features defined on the substrate. The substrate onto which the metal is being plated acts as a cathode. Electrical contacts, such as rings or pins, can allow current to flow through the system. During electroplating, the substrate can be clamped to a head and immersed in the electroplating bath to form a metallization. Metal ions from the bath can be deposited onto the substrate.

In plating systems utilizing an inert anode, an additional source of metal ions may be used to replenish the catholyte solution. The metal ions may be transferred from the anolyte solution into the catholyte through the membrane. Both the catholyte and the anolyte may flow across opposite sides of the membrane, and the membrane may be configured to permit the permeation of the metal ions from the anolyte to the catholyte while restricting the permeation of additives and other materials from the catholyte to the anolyte. The catholyte may then be circulated across the substrate surface during plating to allow the metal ions to plate onto the substrate and form conductive structures.

Air bubbles within the cathode solution or electroplating bath can cause problems with plating. When a substrate is immersed in the bath, air bubbles trapped against the surface of the substrate can prevent the cathode solution from contacting the surface at that location, which can prevent plating at that location and can cause defects or device failure. Removing bubbles from the meniscus across the bath surface can be challenging due to a number of processing aspects. For example, when the substrate is removed from the bath, the liquid dripping back into the bath can cause bubbles to form on the surface. Similarly, subsequent rinse operations can cause droplets to drip onto the bath surface, forming bubbles. Finally, entrained air within the cathode solution can cause bubbles during transfer if not previously removed. While prior art techniques have attempted to limit the formation of bubbles on surfaces, bubbles continue to be a challenge for electroplating operations.

The present technology overcomes these problems by surging the cathode liquid through the electroplating chamber after the electroplating operation, which may facilitate removing bubbles from the surface of the liquid and transporting them out of the plating vessel. As further described below, removing bubbles from the plating bath according to some embodiments of the present technology may limit the time between plating operations while improving plating operations by limiting or neutralizing competing forces that might otherwise retain the bubbles within the vessel. After describing an exemplary system in which embodiments of the present technology may be incorporated, the remainder of the disclosure will discuss aspects of the systems and processes of the present technology.

FIG. 1 illustrates a schematic diagram of an electroplating system (20) according to some embodiments of the present technology. The system may include one or more components for processing substrates, as discussed below. It should be understood that the electroplating system (20) is included as an example of electroplating systems that may benefit from one or more aspects of the present technology. The drawing may provide general structures discussed further below. As illustrated, the electroplating system (20) may include a head (30) positioned above a vessel assembly (50). The vessel assembly (50) may be supported on a relief plate and deck plate (24) that are attached to a stand (38) or other structure. A single electroplating system (20) may be used as a stand-alone unit, or multiple electroplating systems (20) may be provided in arrays, with workpieces or substrates being loaded into and unloaded from the processors by one or more robots. The head (30) may be supported on a lift/rotate unit (34) that may be operated to lift and flip the head to load and unload workpieces into the head, and to lower the head (30) into engagement with the container assembly (50) for processing.

Electrical control and power cables (40) connected to the lift/rotate unit (34) and internal head components may run from the electroplating system (20) to facility connections, or to connections within a multi-processor automation system. A rinse assembly (28) having layered discharge rings may be provided above the vessel assembly (50). A discharge conduit (42) may connect the rinse assembly (28) to the facility discharge, if used. An optional lifter (36) may be provided beneath the vessel assembly (50) to support the anode cup during switching of the anodes. Alternatively, the lifter (36) may be used to hold the anode cup up relative to the remainder of the vessel assembly (50).

Referring to FIG. 2, a cross-sectional view of a portion of an electroplating process system according to some embodiments of the present technology is illustrated, which may illustrate additional details of the electroplating system (20) discussed above. As illustrated, the vessel assembly (50) may include an anode cup (52), a lower membrane support (54), and an upper membrane support (56), held together by fasteners, bolts, or any other mechanism for mechanically joining the components. Within the anode cup (52), a first or inner anode (70) may be positioned near the bottom of a volume or inner anolyte chamber formed between the inner anode and the back side of the membrane (85). The second or outer anode (72) may be located near the bottom of the outer anode chamber or in a volume surrounding the inner anode chamber, which may also be formed between the outer anode and the rear side of the membrane (85). For example, the inner anode (70) may be a flat round metal plate, and the outer anode (72) may be a flat ring-shaped metal plate, which may include a platinum-plated titanium plate or any number of other materials according to embodiments of the present technology.

The inner and outer anode chambers can be filled with copper pellets or can be fluidly coupled to a facility cabinet, such as using piping, pumps, valves, or other components, and the facility cabinet can contain the copper pellets or some other material that can provide metal ions for plating operations according to the present technology, and can be used to plate copper or any other metal or material used in semiconductor processing. As shown in FIG. 2 , the inner anode (70) can be electrically coupled to a first electrical lead or connector (130), and the outer anode (72) can be electrically connected to a separate second electrical lead or connector (132). Unlike many prior designs, in some embodiments of the present technology, the electroplating system can have a central anode and a single, unique outer anode, but still achieve improved performance due to other design features. Having only two anodes instead of three or more can simplify the design and control of the system, and can also reduce the overall cost and complexity of the system. It should be understood that designs including three or more anodes, for example for larger substrates, may also be arbitrarily used.

The upper cup (76) may be contained within or surrounded by the upper cup housing (58) or the chamber body, and the upper cup (76) may be part of a vessel in which a substrate may be placed for performing electroplating operations. The upper cup housing (58) may be attached to and sealed against the upper cup (76). The upper cup (76) may have a curved top surface (124) and a central aperture or opening that may define a central or inner vessel (120) through which cathode solution may flow. This vessel (120) may be defined by a generally cylindrical space within the diffuser (74) that extends into a bell or cone-shaped space defined by the curved top surface (124) of the upper cup (76). A series of concentric annular slots may extend downward from the top curved surface (124) of the upper cup (76). An outer cathode chamber (78), or volume, as further described below, may be formed in the lowermost portion of the upper cup (76), which may be connected to the rings via an array of tubes or other passageways.

The diffuser (74) may be positioned within the central opening of the upper cup (76) and may be surrounded by a diffuser shroud (82). The first or inner membrane (85) may be secured between the upper and lower membrane supports (54 and 56) and may separate the inner anode chamber from the vessel (120). An inner membrane support (88), which may be provided in the form of radial spokes (114) positioned centrally on the upper membrane support (56), may support the inner membrane (85) from above. This design may leave the vessel (120) substantially open, which may better allow for high current flow from the inner anode to the workpiece during plating on the resistive films. The radial spokes may occupy or block less than about 5%, 10%, 15%, or 20% of the cross-sectional area of the vessel (120). Similarly, a second or outer membrane (86) may be secured between the upper and lower membrane supports, separating the outer anode chamber from the outer cathode chamber (78). An outer membrane support (89), which may be provided in the form of radial legs (105 or 116) on the upper membrane support (56), may support the outer membrane from above.

A diffuser cylindrical horizontal supply duct (84) may be formed in the outer cylindrical wall of the upper cup (76), the duct (84) being sealed by O-rings or similar elements between the outer wall of the upper cup (76) and the inner cylindrical wall of the upper cup housing (58). As shown in the drawing, radial supply ducts (80) may extend radially inwardly from the cylindrical duct (84) to an annular shroud plenum (87) surrounding the upper end of the diffuser shroud (82). The radial ducts (80) may pass through the upper cup (76) between vertical tubes connecting the annular slots of the curved upper surface (124) of the upper cup (76) to the outer cathode chamber (78). A current thief assembly (200) may be included, which may include a thief electrode and accommodate an electrolyte or thiefolyte, which may, during operation, help to improve control of edge plating and improve plating uniformity.

During operation, anolyte can be provided into the inner anolyte chamber through a more central inlet through the base of the structure. Anolyte can be provided into the outer anolyte chamber through a radially outer inlet through the base of the structure. Anolyte can flow out of the inner anolyte chamber through the circulation slot (162), and anolyte can flow out of the outer anolyte chamber through the circulation slot (160). Additionally, catholyte can flow upwardly and radially outwardly within the vessel (120). The flow can continue to overflow over a weir (68), which can extend around the vessel, and convey the catholyte into the discharge channel (122). The catholyte can flow from the discharge channel (122) to a return port for recirculation. A cathode liquid level indicator (140) can monitor the cathode liquid level within the discharge channel (122) and/or the upper cup (76). The indicator (140) can be communicatively coupled to a return pump, as shown below, which can be ramped at a higher or lower rate to control the cathode liquid level. It should be understood that the terms anolyte and catholyte, as used herein, refer to the location of the electrolyte in the processor, and do not necessarily refer to any particular chemical composition of the electrolyte.

FIG. 3 illustrates exemplary operations of a method (300) of operating an electroplating system according to some embodiments of the present technology. The method may be performed in a variety of processing systems, which may include the electroplating system (20) described above or any other electroplating system, and may include any of the components, assemblies, or subsystems previously described. The method (300) may be performed to limit bubble formation along the surface or meniscus of the catholyte, which may improve plating uniformity across the wafer. The method (300) may include a number of optional operations, which may or may not be specifically associated with some embodiments of methods according to the present technology. The method (300) may be described in conjunction with the system illustrated in FIG. 4 , which illustrates a schematic cross-sectional view of a portion of an electroplating system (400) according to some embodiments of the present technology. The electroplating system (400) may be schematically illustrated with some of the components of the electroplating system (20) that may be included to facilitate discussion of the operations performed, including the vessel assembly (50) described above, without any intention of limiting the present technology to the schematic diagrams depicted. It should be appreciated that the electroplating system (400) may include any of the components previously described, as well as any number of other components commonly used in electroplating systems.

For example, as discussed in more detail above, the electroplating system (400) can include a vessel (405) that can include an electroplating bath, such as a cathode solution, and can be sized to receive a substrate or wafer for plating. The vessel can be defined by one or more components, such as an upper cup (410) and a weir (415), as discussed above. The cathode solution can flow upwardly through a central channel of the upper cup, as shown, and can flow radially outwardly within the vessel. As described above, the cathode solution can flow in a number of directions within the vessel. The flow can extend beyond the weir (415) into an exhaust channel (420) formed within the chamber housing, and can extend around the vessel, such as outside the upper cup (410) and the weir (415). Additionally, the catholyte can flow from an upper surface of the upper cup through channels formed through the upper cup, through apertures (422) formed from the channels through the base of the upper cup, into a volume (425) defined below the upper cup (410). The volume (425) can be between the upper cup and the membrane (430), wherein the volume can abut a first surface of the membrane (430). As illustrated, the catholyte can flow into the volume through the channels and apertures and sweep along the membrane (430) to receive metal ions from the anolyte. The anolyte can flow through the volume (435) along a second surface of the membrane (430), such as a surface opposite the first surface, which can allow the anolyte to transfer metal ions to the catholyte through the membrane.

The catholyte may exit the system from a number of locations. For example, from the volume (425), one or more first outlets (427) may be coupled to the volume and act as outlets to recover catholyte from the volume. For example, any number of outlets may provide flow from the volume (425) and may extend to a valve (440) that may control flow from the first outlet and provide catholyte to the bath (445), or some other recovery system for replenishment and/or re-delivery into the central channel through the upper cup and into the vessel. Additionally, once received in the outlet channel (420), the catholyte may flow through the second outlet (450) and be pumped back to the catholyte bath (445), such as using a return pump (455). These flows can be controlled to a steady state position to form a meniscus (460) across the top of the vessel and maintained by overflow over a weir. The substrate can then be conveyed into the bath for plating.

As mentioned above, the catholyte may be circulated within the lower volume below the upper cup and may be in ionically connected with the anolyte. Circulation of the catholyte within this volume may help limit crystallization within the anolyte. For example, without adequate circulation of the catholyte to receive ions from the anolyte, the anolyte may become supersaturated near the membrane, which may result in the formation of crystals in the anolyte, which may reduce the ions available for plating on the wafer or substrate. Accordingly, the catholyte may be flowed at a flow rate that ensures adequate transport of the metal ions. However, this flow may provide a force for flow across the weir, which may result in the formation of eddies or ripples across the meniscus, which may cause air to be trapped between the substrate and the catholyte, making plating at such locations challenging. Additionally, this flow can cause bubbles to become trapped along the surface of the meniscus, which can then become trapped against the substrate, limiting plating at that location.

As described above, when the substrate is removed from the plating bath after the electroplating operation, the cathode or electrolyte bath fluid may drip back into the vessel, causing bubbles to form along the surface. These bubbles should flow with the cathode over the weir and be removed from the plating bath without being entrained in the system. However, due to the cathode flow through the upper cup, the bubbles may become trapped in the vortices along the meniscus, and flow over the weir may not remove these bubbles from the system. The present technique can adjust the flow within the vessel to increase the flow over the weir, which can improve bubble removal from the system. Simply increasing the inlet flow rate may be insufficient to address bubble retention due to competing flow through the upper cup. For example, if the inlet flow is simply increased by a certain amount, the flow through the upper cup may also increase, which may increase the force along the meniscus and worsen the flow characteristics and bubble retention. Accordingly, the present technique can increase the flow over the weir as well as change the flow through the upper cup, which may help to remove bubbles from the surface and ensure a better meniscus for subsequent processing.

The method (300) may include operations to facilitate bubble removal from the plating bath, which may be performed during or between wafer plating processes. For example, at optional operation (305), an electroplating operation may be performed on a semiconductor substrate immersed in the plating bath or cathode solution. Once completed, at operation (310), the substrate may be removed or withdrawn from the electroplating bath. These operations, as well as any rinsing operations performed on the substrate, may cause fluid droplets to be released back into the bath, which may result in bubble formation as discussed above. The method (300) may then adjust the cathode solution flow through the system to improve bubble removal before a subsequent wafer is placed in the bath for plating.

The method (300) may include, at operation (315), diverting the flow through the first outlets. Diverting the flow may occur in any number of ways, and in systems where each of the outlets includes a valve through which flow is provided, such as valve (440) discussed previously, the flow from the first outlets may be reduced by at least partially closing the valve, and in some embodiments may include completely closing the valve. This may stop any counteracting flow within the vessel and cause all fluid to flow beyond the weir, which may reduce turbulent interference and cause all fluid to flow more laminarly into the outlet channel beyond the weir. Additionally, in some embodiments, since the inlet flow may be maintained or increased, the flow into the outlet channel and the second outlet may be increased at operation (320). In some embodiments, the inlet flow may not be increased, and the increased flow may only result from the absence of additional outlet paths. This can control the amount of fluid level rise within the discharge channel, which can limit the time losses to return to normal operation.

For example, the increased secondary flow, or flow over the weir, may be performed for a first amount of time, after which time the valve may be returned to its previous operating position or open, which may increase the flow from the first discharge or discharges. This may cause the secondary flow to be reduced or decreased, such as in an optional operation (325), when the system returns to its previous levels. By controlling the amount of additional flow over the weir and ensuring that the volume within the discharge channel is allowed to appropriately decrease, improved performance may be provided because the liquid level within the discharge channel can directly affect the operation of the system. For example, as the flow over the weir is allowed to increase to remove bubbles, the liquid level within the discharge channel may rise from the first level (470a) to the second level (470b), which may be relative and are not necessarily specific levels but are exemplified by way of example only. As substrates are transferred into the bath, large volumes of cathode fluid can be forced over the weir and into the discharge channel. If the fluid level within the discharge channel is not allowed to decrease prior to transfer of the subsequent wafer, splashing or overflowing onto the head or other system components can occur, which can cause damage to the equipment.

As noted above, a liquid level sensor (475) may be positioned within the discharge channel (420) and may monitor the fluid level. The sensor may be communicatively coupled to the return pump (455), and the return pump may be ramped higher or lower to increase or decrease flow from the discharge channel in response to receiving a signal from the level sensor indicating an increase or decrease in the catholyte level within the discharge channel. However, simply ramping the pump to overcome the fluid increase may similarly be insufficient. For example, the pump may not be sized to overcome the volume change based on the increased flow over the weir, which may cause the fluid level to rise. Additionally, an increased removal rate that is too high may cause the liquid level within the discharge channel to drop too low, which may cause air to become entrained within the system. Accordingly, in some embodiments, the inflow transfer rate may be maintained during the method (300), and a second time period may occur prior to transfer of a subsequent wafer, during which the liquid level within the discharge channel may be lowered to a level similar to that prior to the first time period. This may allow bubbles to be removed from the system, while still ensuring uniform processing conditions between wafers.

The first time period can begin at any point after the electroplating operation is completed, and can begin as soon as the substrate is withdrawn from the vessel and plating bath. Once all or increased flow has extended beyond the weir, a sufficient period of time may elapse before the exhaust channel becomes overwhelmed, and thus the first time period can be limited to ensure that the exhaust channel does not become overfilled while clearing the bubbles. To limit the opportunity to overwhelm the exhaust channel and to limit throughput losses during performance of the method, the first time period can be maintained to less than about 60 seconds, less than about 55 seconds, less than about 50 seconds, less than about 45 seconds, less than about 40 seconds, less than about 35 seconds, less than about 30 seconds, less than about 25 seconds, less than about 20 seconds, less than about 15 seconds, less than about 10 seconds, less than about 5 seconds, or less.

The second time period can be any of these mentioned time periods, and can be equal to, greater than, or less than the amount of time of the first time period. Accordingly, the entire process of increasing flow over the weir to remove bubbles, and then allowing the system to return to pre-treatment conditions after flow to the first outlets is fully resumed, can be less than or equal to about 2 minutes, less than or equal to about 90 seconds, less than or equal to about 60 seconds, less than or equal to about 50 seconds, less than or equal to about 40 seconds, less than or equal to about 30 seconds, less than or equal to about 20 seconds, less than or equal to about 10 seconds, or less. By controlling the time and inlet flow for the method as well as the pumping speed for the return pump, the liquid level in the discharge channel during the method can be prevented from rising more than about 5 cm, more than about 4 cm, more than about 3 cm, more than about 2 cm, more than about 1 cm, more than about 9 mm, more than about 8 mm, more than about 7 mm, more than about 6 mm, more than about 5 mm, more than about 4 mm, more than about 3 mm, or less.

In some embodiments, one or more components may also facilitate bubble removal from the system. FIG. 5 illustrates a schematic perspective view of a slotted weir (500) according to some embodiments of the present technology. The weir (500) may be used in place of any of the weirs previously discussed, including, for example, the weir (68) and the weir (415). The weir (500) may be castellated and may have one or more slots or notches (505) formed from an upper surface of the weir and extending at least partially through an outer edge of the weir. This may improve fluid flow over the weir and, in some embodiments, improve bubble removal. While weirs characterized by a uniform, flat outer profile may be used in embodiments of the present technology, the slotted weir may limit dry spots and increase flow at the slot locations. For example, on a flat weir, flow over an edge may not be uniform around the weir, and bubbles may collect at locations where flow does not propagate over the edge of the weir. However, the notches can reduce the surface tension and increase the surface flow at each notch location. This can further improve bubble removal by causing increased flow at each notch location to draw fluid over or through the weir. Accordingly, in some embodiments, slotted weirs can be utilized to further improve bubble removal from the system.

Some embodiments of the present technology can additionally increase the flow over the weir by reversing the flow through the upper cup, such that both flows extend over the weir. FIG. 6 illustrates exemplary operations of a method (600) of operating an electroplating system, according to some embodiments of the present technology. The method (600) may be performed in any of the systems previously described and may include any of the operations discussed with respect to method (300). For example, the method (600) may optionally include performing an electroplating operation (605), and, at operation (610), removing the substrate from the plating bath and vessel. In some embodiments, the method (600) may cause both flow paths to extend over the weir. For example, as previously described, at operation (615), the first flow may extend through the central channel of the upper cup and over the weir. Additionally, in some embodiments, a secondary pump (480) may be included in the system and engaged to cause the second flow in operation (620) to deliver the catholyte back through the valve (440) into the outlets (427). The flow may then be forced upward through the apertures and channels of the upper cup, such as along the flow path (485), which may further increase the flow over the weir and provide a uniform flow direction through the chamber, which may improve bubble removal from the system. While discussed as operations, it should be understood that the flows may be performed during and subsequent to the plating operations, or, in some embodiments, the second flow may be reversed subsequent to electroplating.

By reversing the flow through the first outlets as compared to the previously described process, the flow through the membrane can be maintained during the bubble removal process, which can ensure that ion transport through the membrane is not affected by the process. The process can be performed for any length of time, such as any of the time periods specified above. By performing flow adjustments according to embodiments of the present technology, bubble removal can be improved as compared to conventional systems while limiting the impact on treatment throughput. Additionally, the present technology can be readily retrofitted to existing systems, which may in some embodiments not require component replacement or system reconfiguration.

In the preceding description, numerous details have been set forth for purposes of explanation in order to provide an understanding of various embodiments of the present technology. However, it will be apparent to one skilled in the relevant art that certain embodiments may be practiced without some of these details, or with additional details. For example, other substrates that may benefit from the described wetting techniques may also be used with the present technology.

While several embodiments have been disclosed, it will be recognized by those skilled in the art that various modifications, alternative configurations, and equivalents may be used without departing from the spirit of the embodiments. Additionally, many well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present disclosure. Accordingly, the above description should not be considered to limit the scope of the present disclosure.

Where a range of values is provided, it is understood that each intermediate value, up to the smallest fraction of a unit of the lower limit, between the upper and lower limits of that range is also specifically disclosed, unless the context clearly dictates otherwise. Any narrower range between any of the stated or non-stated intermediate values in the stated range and any other stated or intermediate value in that stated range is included. The upper and lower limits of such smaller ranges may independently be included or excluded within the range, and each range in which either of the limits is included, neither of the limits is included, or both of the limits is included is also included within the disclosure, subject to any specifically excluded limit in the stated range. Where a stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included. Where multiple values are provided in a list, any range including or based on any of those values is similarly specifically disclosed.

As used herein and in the appended claims, unless the context clearly dictates otherwise, the singular forms also include plural references. Thus, for example, reference to "a material" includes a plurality of such materials, reference to "a channel" includes reference to one or more channels and equivalents thereof known to those skilled in the art, and so on.

Additionally, when the words "comprises," "includes," "contains," "comprising," "includes," and "having" are used in this specification and the following claims, they are intended to specify the presence of stated features, integers, components, or acts, but they do not preclude the presence or addition of one or more other features, integers, components, acts, operations, or groups.

Claims (20)

As a semiconductor processing method,
A step of performing an electroplating operation on a semiconductor substrate in an electroplating bath within a vessel of an electroplating system;
A step of removing the semiconductor substrate from the electroplating bath;
A step of closing a valve associated with a first discharge from said electroplating system; and
A step of increasing the flow from said electroplating system to a second discharge portion, said second discharge portion being associated with a discharge channel from a vessel of said electroplating system.
A semiconductor processing method comprising: In the first paragraph,
A method of processing a semiconductor, wherein said vessel comprises a weir around said vessel, and increasing flow to said second discharge portion increases flow beyond said weir into said discharge channel providing access to said second discharge portion. In the second paragraph,
A semiconductor processing method, wherein the weir defines a plurality of notches extending from an upper surface of the weir. In the first paragraph,
A method of processing a semiconductor, wherein the vessel comprises an upper cup, the upper cup defining a plurality of channels through an upper surface of the upper cup, and at least one aperture coupling each of the plurality of channels to a volume within the vessel in fluid contact with a membrane. In paragraph 4,
A semiconductor processing method, wherein a cathode fluid flows within the volume, and the volume is in contact with the first surface of the membrane. In paragraph 5,
A semiconductor processing method further comprising the step of flowing an anode solution into contact with a second surface of the membrane opposite to the first surface of the membrane. In paragraph 5,
A semiconductor processing method, wherein said first discharge portion is associated with one or more discharge outlets of said volume within said container. In paragraph 5,
A semiconductor processing method, wherein a central channel is defined through the upper cup, a cathode solution flows into the vessel through the upper cup, and during the electroplating operation, the cathode solution flow extends not only into each of the plurality of channels but also beyond a weir extending around the vessel. In the first paragraph,
The above electroplating system,
A return pump fluidly coupled to the second discharge portion; and
A level sensor disposed within the discharge channel, wherein the level sensor is communicatively coupled to the return pump.
A semiconductor processing method further comprising: In Article 9,
A semiconductor processing method, wherein said return pump is operable to increase the flow rate from said second discharge port in response to a signal from said level sensor indicating an increase in the level of cathode solution within said discharge channel. As a semiconductor processing method,
A step of performing an electroplating operation on a semiconductor substrate in an electroplating bath within a vessel of an electroplating system;
A step of removing the semiconductor substrate from the electroplating bath;
A step of diverting flow from the above electroplating system to a first discharge portion;
A step of increasing a flow from said electroplating system to a second discharge, said second discharge being associated with a discharge channel from a vessel of said electroplating system, wherein increasing the flow to said second discharge occurs during a first time period; and
A step of reducing the flow from the electroplating system to the second discharge portion after the first time period.
A semiconductor processing method comprising: In Article 11,
A semiconductor processing method further comprising the step of increasing the flow to the first discharge portion while reducing the flow to the second discharge portion after the first time period. In Article 11,
A method of processing a semiconductor, wherein said vessel comprises a weir around said vessel, and increasing flow to said second discharge portion increases flow beyond said weir into said discharge channel providing access to said second discharge portion. In Article 13,
A method of operating an electroplating system, wherein the weir defines a plurality of notches extending from an upper surface of the weir. In Article 13,
A method of operating an electroplating system, wherein the vessel comprises an upper cup, the upper cup defining a plurality of channels through an upper surface of the upper cup, and at least one aperture coupling each of the plurality of channels to a volume within the vessel in fluid contact with a membrane. In Article 15,
A method of operating an electroplating system, wherein a central channel is defined through said upper cup, cathode solution flows into said vessel through said upper cup, and during said electroplating operation, the cathode solution flow extends not only into each of said plurality of channels but also beyond said weir. In Article 11,
A semiconductor processing method, wherein while increasing the flow to the second discharge portion, the height of the cathode solution increases within the discharge channel by about 2 cm or less. In Article 11,
A semiconductor processing method, wherein the first time period is about 30 seconds or less. As a semiconductor processing method,
A step of performing an electroplating operation on a semiconductor substrate in an electroplating bath within a vessel of an electroplating system, said vessel including a weir around said vessel;
A step of removing the semiconductor substrate from the electroplating bath;
providing a first flow through said electroplating system through a central channel through said container; and
A step of providing a second flow through said electroplating system through said vessel and through secondary channels radially outwardly of said central channel, said first flow and said second flow extending from the vessel of said electroplating system into a discharge channel, said flow into said discharge channel extending beyond said weir into said discharge channel providing access to a discharge portion;
A semiconductor processing method comprising: In Article 19,
A semiconductor processing method, wherein the weir defines a plurality of notches extending from an upper surface of the weir, and while increasing the flow to the second discharge portion, the height of the cathode solution within the discharge channel increases by about 2 cm or less.

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