Patent Application
20240213066
The present invention relates to a frame system for holding a substrate during a chemical and/or electrolytic surface treatment of the substrate.
Wet chemical processing of substrates or work pieces is one of the most used technologies in many different industries, especially in the semiconductor related industry, to clean or etch a surface of the substrates. The wet chemical processing allows a high chemical selectivity, which can be achieved with various process liquids (such as acids, bases, oxidizers, etc.) or simple or complex mixtures thereof. In addition, the wet chemical processing allows an inherent simplicity of the processing, scalability of the process to various types of substrates having various sizes and a low cost of operation. An additional advantage of the wet chemical processing is that both sides of a flat substrate surface including the edges and sides, or multiple sides of a substrate having a complex geometry can be processed at the same time. It is also possible to process multiple substrates at the same time. Accordingly, the wet chemical processing is applied for a removal of random surface contamination, for a targeted removal of unwanted parts of material layers for further processing in order to create device patterns on the surfaces of the substrate.
In order to achieve a desired surface quality and processing uniformity, it is essential to provide reliable mounting and holding means of the substrate during and after the wet chemical process such as rinsing and drying process at the end of the wet chemical process. Conventional substrate holding frames or chucks consist of two frame parts, an upper and a lower half-frame and a substrate is arranged between them by means of mechanical force. Some frames are clamped together and others are manually screwed together, especially for large size substrates.
Hence, there may be a need to provide a reliable mounting and holding means of a substrate, which facilitates securing the substrate, thus increasing a quality of a substrate treatment.
The problem is solved by the subject matter of the independent claim of the present invention, wherein further embodiments are incorporated in the dependent claims.
According to the present disclosure, a frame system is presented. The frame system is configured for holding a substrate during a chemical and/or electrolytic surface treatment of the substrate. The frame system comprises a frame element and several finger units arranged at the frame element. The frame element is configured to at least partially surround lateral edges of the substrate and to spare at least a first surface or a second surface of the substrate to be accessible for the surface treatment. Each finger unit comprises a first finger and a second finger. The first finger is configured to contact the first surface of the substrate and the second finger is configured to contact the second surface of the substrate opposite to the first surface of the substrate. The first finger is movable relative to the frame element to clamp the substrate between the first finger and the second finger.
The frame system according to the present disclosure allows a simple, fast, and reliable loading and unloading of the substrate automatically or manually. The frame system further ensures excellent and stable securing of and electrical contact to the substrate eliminating the risk of a substrate breakage and/or harmful electrostatic charging of the substrate during the treatment. In addition, the frame system permits highly efficient and effective chemical processing on all sides of the substrate by an aerodynamically optimized frame system.
The chemical and/or electrolytic surface treatment of the substrate may be any material deposition, galvanizing coating, chemical or electrochemical etching, anodal oxidation, metal separation process or the like. The frame system may be a substrate holder, at which the substrate may be securely held. The substrate may comprise a conductor plate, a semi-conductor substrate, a film substrate, an essentially plate-shaped, metal or metallized workpiece or the like. The substrate may be mounted to the frame system before the chemical and/or electrolytic surface treatment in a processing system is carried out. Accordingly, the frame system allows a safe and non-damaging transfer of the substrate between the loading/unloading station and the processing system.
The frame system may be immersed into an electrochemical deposition tank containing a process fluid and/or an electrolyte for a current distribution. The frame element may comprise at least one, preferably several frameworks assembled together to form a cavity in their center to receive the substrate. The frame element may comprise a rectangular, circular or polygonal shape and at least partially encompass the substrate. The substrate may be substantially plate-shaped such that the frameworks may be aligned with the lateral edges of the substrate. Accordingly, the first surface and the second surface of the plate-shaped substrate may expose to the electrolyte for the surface treatment.
The finger unit may be manufactured integrally with the frame element or arranged releasably at the frame element. In the latter case, the finger unit may be clamped, screwed or the like in order to separate the finger unit individually from the frame element. The finger units may be arranged along the frame element or frameworks and directed to the cavity. In other words, the finger units may protrude from the frame element in direction to the cavity to hold the lateral edges of the substrate. Still in other words, the finger units may also at least partially surround the substrate. The finger units may be configured to hold the substrate with a minimum required force not to cause a breakage or unwanted mechanical transformation. Each finger unit may comprise a pair of fingers or pins consisting of a first finger and a second finger corresponding to each other.
The frame element may comprise a first side or a first frame member and a second side or a second frame member, wherein the first frame member and the second frame member may be separated from each other. The first side or the first frame member may at least partially surround the first surface of the substrate and the second side or the second frame member may at least partially surround the second surface of the substrate. The first frame member may comprise at least one framework and the second frame member may also comprise at least one framework.
The first fingers of the finger units may be arranged at the first side or the first frame member of the frame element and the second fingers of the finger units may be arranged at the second side or the second frame member of the frame element. Alternatively, the first fingers may be arranged at the second side or the second frame member and the second fingers may be arranged at the first side or the first frame member. Further, the first fingers and the second fingers of the finger units arranged along the frame element may be alternately disposed at the first side or the first frame member and the second side or the second frame member.
The first finger of the finger unit may be movable or displaceable relative to the frame element and the second finger of the finger unit may be fixedly arranged at the frame element. Alternatively, the first finger may be fixedly attached to the frame element and the second finger may be movable relative to the frame element. The term “movable” may be understood so that the fingers may be displaced between a closed position and an open position along the frame element to hold or release the substrate between the first and the second finger. Preferably, the first finger or the movable finger may be mounted rotatably at the frame element to apply a clamping force in the closed position.
In an example, the finger units are made of electrically conductive polymers, electrically conductive ceramics, or metallic materials. The finger units can be also made of electrically nonconductive polymers, electrically nonconductive ceramics, or electrically nonconductive plastic materials.
In an example, the frame element and/or the finger units are made of stainless steel, aluminum or titanium. The frame element and/or the finger units may be also made of a chemically compatible or chemically incompatible material and further coated with a chemical compatible polymer. In an example, the frame element and/or the finger units may be coated with a polymer, perfluoro alkoxy alkanes (PFA), ethylene chlorotrifluoroethylene copolymer (ECTFE), polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), or fluorinated ethylene propylene (FEP). In an example, the first finger and the second finger may be made of the same material as the frame element or a different material of the frame element.
In an example, the second finger is unmovable. In other words, the second fingers of the finger units are fixedly attached to the frame element and only the first fingers may be movable relative to the frame element and/or the second fingers. Still in other words, the second fingers may be mounted in a fixed position at the frame element and the first finger units may rotate relative to the second fingers to apply clamping force for holding the substrate. During loading the substrate onto the frame element, the second surface of the substrate may be placed onto the second fingers, which may serve as a reference position for the substrate.
In an example, the second finger is movable relative to the frame element. In other words, both the first fingers and the second fingers of the finger units may be movable relative to each other such that they may be opened relative to the frame element, which may receive a substrate between the first and the second fingers. This may be particularly useful if more than one substrate may be mounted to the frame element.
In an example, the several finger units are distributed along the frame element with distances between adjacent finger units. The finger units may be arranged at the frame element, preferably at the lateral frameworks of the frame element, which are arranged parallel relative to an immersing direction of the frame system into the deposition tank. The finger units may be spaced from each other along the frame element. The finger units may face each other relative to a transversal direction of the frame element or they may be arranged offset with respect to one another relative to the transversal direction of the frame element. Accordingly, the finger units may be arranged to optimally and reliably hold the substrate without causing any damages or unwanted mechanical transformation.
In an example, the frame system further comprises an actuation unit configured to move the first finger between an open position for receiving and/or releasing the substrate and a closed position for holding the substrate. The actuation unit may be also configured to move the second finger between an open position for receiving and/or releasing the substrate and a closed position for holding the substrate. The actuation unit may be configured to move a plurality of first fingers simultaneously such that the first fingers may be moved together between the open position and the closed position. The actuation unit may be also configured to move a plurality of second fingers simultaneously such that the second fingers may be moved together between the open position and the closed position.
The actuation unit may comprise a cylinder mechanism, which actuates a movement of the finger units between the open position and the closed position. The actuation unit may be arranged at the frame element, preferably inside the frame element, more preferably at an upper portion of the frame element, which is not immersed into the deposition tank to protect the actuation unit. The actuation unit may be connected to a control unit, which operates the cylinder mechanism to induce a movement of the finger units and/or frame element. The control unit may be electrically driven or apply pneumatic force. Accordingly, the loading and/or unloading of the substrate may be fully automated.
In an example, the frame system further comprises a pre-tension unit configured to keep the first finger in a rest position, which is the closed position. The pre-tension unit may be also configured to keep the second finger in a rest position, which is the closed position. The pre-tension unit may interconnect the frame element and the actuation unit to cause a movement of the first fingers. In other words, the pre-tension unit may be coupled with the actuation unit on one side and the frame element on the other side. The pre-tension unit may also interconnect the frame element and the actuation unit to cause a movement of the second fingers.
The pre-tension unit may comprise a spring element connected on one side to the actuation unit or the cylinder mechanism and on the other side to a guide element coupled with the frame element. The spring element may push or release the guide element with respect to the movement of the cylinder mechanism.
Between the spring element and the guide element a gear rack element may be arranged. The guide element may comprise a tooth structure at a surface, which is in contact with the gear rack element. Hence, if the cylinder mechanism presses the spring element, the spring element may push the guide element, which rotates the gear rack element. Accordingly, the frame element coupled with the gear rack element may be rotated to open the finger units.
Alternatively, the gear rack element may be attached to a supporting element inserted into the frame element and directly connected to the finger units. Hence, when rotating the gear rack element, the supporting element may be rotated, and the finger units may be opened without any movement of the frame element. A number of teeth of the gear rack element, length of the guide element and/or a cylinder stroke of the cylinder mechanism may result in a controlled rotation of the frame element and/or the finger units, preferably 180° rotation of the frame element and/or the finger units.
If the cylinder mechanism returns to its original position, the spring element may rest and the guide element may be released, which corresponds to the closed position of the finger units. Since the spring element tends to being in a rest or released state, the pre-tension unit may ensure a self-closing of the finger units when the cylinder mechanism is not actuated. Accordingly, the substrate held by the finger units may not escape from the frame element. In summary, the open position of the finger units may be performed by operating the actuation unit or the cylinder mechanism and the closed position of the finger units may be performed by releasing the pre-tension unit.
In an example, the first finger and/or the second finger comprise an elastic fingertip element to contact the substrate. An end surface or a distal position of the first and/or the second finger directly contacting the substrate may comprise an elastomer element. The elastomer material for the fingertip element of the first finger and/or the second finger may be chemically resistant such that the elastic fingertip element may not be adversely affected by the electrolyte or any other chemicals used during the treatment. The clamping forces exerted by the finger unit and transferred to the elastic fingertip element of the first and/or the second fingers may be capable to fixedly and securely hold a large size substrate in the closed position. The contact points of the finger units with the surface of the substrate may be also configured to avoid unwanted etch patterns being created during a material removal process step.
In an example, the fingertip element is made of rubber, ethylene-propylene-diene-monomer (EPDM), fluoroelastomer (FPM/FKM), or perfluoroelastomer (FFKM). Such materials may be capable to reduce or even dampen any mechanical stresses or vibrations, which may transfer to the substrate. Further, such materials may be chemically compatible with the processing environment such that the fingertip elements may not be decomposed during the treatment of the substrate, which may otherwise loosen the holding of the substrate.
In an example, at least one of the finger units comprises an electrically conductive grounding path for an electrical grounding of the substrate. Accordingly, an electrical grounding of the substrate may be ensured at all times, to avoid or at least minimize electrostatic charging of the substrate during the chemical and/or electrolytic surface treatment.
In an example, the finger units, the first finger, the second finger and/or the fingertip are exchangeable. The finger units or any parts of the finger units such as fingertips may be separately manufactured and mounted at the frame element or any remaining portion of the finger units. Accordingly, finger units may be assembled individually and optimally in accordance with any requirements or properties of the substrate or the chemical environment. In an example, each finger unit arranged at the frame element may be differently assembled such that each first and/or second finger unit may comprise a different shape or fingertip element made of different material.
In an example, an outer edge of the frame element is pointed and the outer edge is preferably directed to a bottom of the frame system. The framework arranged at a lower portion of the frame element, which firstly contacts the electrolyte when immersing the frame system into the deposition tank, may be tapered in an outer direction. Accordingly, a high-speed immersion and/or extraction of the frame system into and/or out of the deposition tank may be facilitated and splashing of electrolyte and/or chemicals may be avoided. This may be particularly important in case of a high-speed immersion etching process, which may be required to achieve a high process throughput and the best possible top to bottom etch uniformity. Additionally, the pointed design of the frame element may allow an easy removal of residual droplets of a rinsing fluid during a drying process.
In an example, the frame element and/or the finger units comprise a fluid guiding system configured to guide a fluid away from the substrate, preferably in a direction to the bottom of the frame system. The fluid guiding system may comprise a gas stream unit configured to provide a drying gas, preferably from the upper portion to the lower portion of the frame element such that a rinsing fluid film or droplets may be removed downwards and outside the frame system. Accordingly, the rinsing fluid transported away from the frame system or the substrate may not be in contact with the substrate again. For example, the rinsing fluid may be a deionized water and the drying gas may be air or nitrogen gas. The drying process may be performed with gases at elevated temperatures, for example air heated to 70° C. or any other process-optimized temperature.
In an example, the frame element and/or the finger units are hydrophobic or hydrophilic. In other words, the frame element and/or the finger units may be coated with a hydrophobic or a hydrophilic material to facilitate the drying process in order to completely remove any residual droplets.
In an example, the frame element and/or the finger units are designed without an undercut. In other words, the frame element and/or the finger units do not comprise any hidden corners or areas, where chemicals or electrolyte may be collected, or droplets of the rinsing fluid may be retained. Such an aerodynamically optimized geometry of the frame element and/or the finger units may enable an effective and efficient rinsing and drying of the frame system and/or the substrate.
In an example, the frame system further comprises only one or two finger units per 500 mm length of substrate. The frame system may comprise a minimum amount of finger units to contact the substrate surface to secure the substrate in place, particularly for high-speed movements. The minimum number of required finger units may depend on dimensions of the substrate. For example, for a 500×550 mm substrate only two finger units may be arranged on each lateral side of the frame element, which is parallel to the immersing direction of the frame system in the deposition tank.
In an example, the frame element further comprises at least one resting unit arranged at a bottom edge of the frame element and configured to support the substrate. The resting unit may comprise a resting surface receiving a lower edge of the substrate. Accordingly, the substrate may be reliably retained in place in a vertical direction. The resting surface may be formed very thin and/or tapered in the direction of the substrate to avoid back splashing of the electrolyte and/or droplets. The resting unit may be formed integrally with the frame element or separately manufactured and releasably attached to the frame element. Further, the resting unit may serve as a reference for an automatic loading and/or unloading of the substrate into and from the frame element.
In an example, the frame system further comprises only one unitary frame element. In other words, the all frameworks and/or the first and second frame members of the frame element may be integrally arranged to form a unitary frame element. Accordingly, loading/unloading of the substrate to the frame system may be facilitated through assembling the frame system.
According to the present disclosure, also a use of the frame system as described above for chemically and/or electrochemically processing a substrate, in particular a large substrate, is presented. The chemically and/or electrochemically processing may apply a High Speed Plating (HSP) technology. In an HSP system, at least one substrate is immersed into a deposition tank containing an electrolyte and chemically and/or electrochemically treated.
It should be noted that the above embodiments may be combined with each other irrespective of the aspect involved.
These and other aspects of the present invention will become apparent from and elucidated with reference to the embodiments described hereinafter.
Exemplary embodiments of the invention will be described in the following with reference to the following drawings.
The frame system 10 comprises a frame element 30 and several finger units 60 (see also
The frame system 10 may comprise a minimum amount of finger units 60 to contact the substrate surface 21, 22 to secure the substrate 20 in place, particularly for a High Speed Plating (HSP) system. The minimum number of required finger units 60 may depend on the dimensions, weight, as well as on the chemical and physical properties of the substrate material and the surfaces properties of the substrate 20.
The finger units 60 may be manufactured integrally with the frame element 30 or releasably attached to the frame element 30. As shown in
The frame element 10 and/or the finger units 60 may be made of stainless steel, aluminum or titanium. The frame element 10 and/or the finger units 60 may be made of a chemically compatible or chemically incompatible material and may be further coated with a chemical compatible polymer.
The frame element 30 and/or the finger units 60 are designed without an undercut (see
The frame element 30 further comprises a bottom framework 33 and an outer edge of the bottom framework 33 is pointed (see
The bottom framework 33 of the frame element 30 comprises at least one resting unit 70, which is configured to support the substrate 20 (see
As shown in
Along with opening or closing the finger units 60, the first fingers 61 may be movable between a closed position and an open position to hold or release the substrate 20 between the first finger 61 and the second finger 62, as shown in
The frame system 10 further comprises a pre-tension unit 50 configured to keep the movable first finger 61 in a rest position, which is the closed position. The pre-tension unit 50 comprises a spring element 51 connected on one side to the actuation unit 40 or the cylinder mechanism 41 and on the other side to a guide element 52 coupled with the frame element 30 or the first frame member 31 of the frame element 30. The spring element 51 may push or release the guide element 52 with respect the movement of the cylinder mechanism 41. The guide element 52 comprises a gear rack element 53 coupled with the frame element 30 or the first frame member 31 of the frame element 30.
If the cylinder mechanism 41 presses the spring element 51, the spring element 51 pushes the guide element 52, which rotates the gear rack element 53. The guide element 52 may comprise a tooth structure at a surface, which is in contact with the gear rack element 53. Accordingly, the guide element 52 rotates the gear rack element 53 when the guide element 52 is pressed by the spring element 51, which may lead to a rotation of the frame element 30 or the first frame member 31 of the frame element 30 coupled with the gear rack element 53 to open the finger units 60.
If the cylinder mechanism 41 returns to its original position, the spring element 51 may rest and the guide element 52 may be released, which corresponds to the closed position of the finger units 60. Since the spring element 51 tends to being in a rest or released state, the pre-tension unit 50 may ensure a self-closing of the finger units 60 when the cylinder mechanism is not actuated.
In
The frame system 10 may further comprise a fluid guiding system (not shown) configured to guide a fluid away from the substrate 20, preferably in a direction to the bottom of the frame system 10. The fluid guiding system may comprise a gas stream unit configured to provide a drying gas, preferably from the upper portion to the lower portion of the frame element 30 such that a rinsing fluid film or droplets may be removed downwards and outside the frame system 10.
It has to be noted that embodiments of the disclosure are described with reference to different subject matters. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application. However, all features can be combined providing synergetic effects that are more than the simple summation of the features.
While the disclosure has been illustrated and described in detail in the drawings and description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The disclosure is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed disclosure, from a study of the drawings, the disclosure, and the dependent claims.
In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21170245.1 | Apr 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/053829 | 2/16/2022 | WO |
