System and method for a surface treatment of a substrate with a liquid

Abstract

The present invention relates to a system (17) for surface treatment of a substrate (1) using a liquid, comprising: a first substrate holder (18), a second substrate holder (19), a liquid application unit (21), a processing chamber (20), and a control unit (22), wherein the first substrate holder (18) is configured to hold the substrate (1), and wherein the first substrate holder (18) is movable within the processing chamber (20) and configured to deliver the substrate (1) to the second substrate holder (19). The second substrate holder (19) is rotatable and configured to hold the substrate (1) during rotation of the substrate (1) within and relative to one of the processing chambers (20). The liquid application unit (21) is movable relative to the second substrate holder (19) and configured to apply the liquid to the substrate (1). The control unit (22) is configured to control the rotational speed of the substrate (1), the position of the liquid application unit (21), and / or the application rate of the liquid. Furthermore, the present invention also relates to a method (100) for surface treatment of a substrate (1) using a liquid, and to a computer program element of a system (17) for surface treatment of a substrate (1) using a liquid.

Description

Technical Field

[0001] The present invention relates to a system for surface treatment of a substrate using a liquid, a method for surface treatment of a substrate using a liquid, and a computer program element for a system for surface treatment of a substrate using a liquid. Prior Technology

[0002] In semiconductor processing, a substrate (such as a wafer) is exposed to numerous material deposition or growth steps to create an electronic device. During these steps, material is deposited not only on one side of the substrate (which is typically one of the front sides of the substrate) but also on the other sides, typically on the back side of the substrate and in the area surrounding the edges of the substrate. Most of the material deposits or growth layers on the back side of the substrate and around the edges are unwanted and must be removed without damaging or removing any material deposits and / or growth layers on the front side of the substrate (especially in a critical region on the front side of the substrate). A critical region is defined as an area configured to be used as part of an electronic device (e.g., a sensor and the like).

[0003] Removal of material deposits and / or growth layers from the back side and edges of a substrate is typically performed by a so-called back bevel etching / cleaning procedure (which can also be simply a so-called back bevel cleaning procedure if only contaminants such as particulate matter need to be removed).

[0004] During a back-side bevel etching / cleaning process, material deposits and / or growth layers are removed from the back side of the substrate and around its edges, as well as from a so-called "edge exclusion zone" that extends at least partially over the front side of the substrate. The edge exclusion zone is an area of ​​the substrate that is not used or cannot be used to produce a functional electronic device.

[0005] In common manufacturing environments, many different technologies used to produce electronic devices are processed in parallel through a set and qualified processing line, which includes one of the processing systems, referred to below as equipment, and can be easily and quickly adapted to the specific requirements of each of the various technologies.

[0006] An edge exclusion zone is formed by depositing and / or growing a material layer in a predefined area on the front side of the substrate before removal. The formation of the edge exclusion zone is a critical part of the back-side bevel etching / cleaning process because it needs to be reproducible for at least several wafers using the same technology, and additionally, it requires a uniform and substantially straight bend around the substrate to meet the technical requirements of the resulting electronic device. Specifically, the term "straight bend" can mean "bend at a specific radius" or "edge off."

[0007] In the prior art, changes in one of the requirements for the edge exclusion zone necessitate significant changes to the equipment, resulting in very high adaptation efforts, for example, due to the need to replace critical components, and / or due to the inability to achieve the required accuracy for generating the edge exclusion zone without equipment replacement. Therefore, adjusting the equipment to meet changing technical requirements incurs significant additional costs and / or time, and / or limits the achievable accuracy of the edge exclusion zone. Summary of the Invention

[0008] Therefore, there may be a need for an improved system for surface treatment of a substrate using a liquid, which allows for reduced adjustment effort while providing the required accuracy for generating edge exclusion zones.

[0009] This problem is solved by the subject matter of the independent claim, wherein further embodiments are incorporated in the appendix claim. It should be noted that the form of the invention described below is also applicable to a system for surface treatment of a substrate using a liquid, a method for surface treatment of a substrate using a liquid, and a computer program element for a system for surface treatment of a substrate using a liquid.

[0010] According to the present invention, a system for surface treatment of a substrate using a liquid is provided. The system includes a first substrate holder, a second substrate holder, a liquid application unit, a processing chamber, and a control unit. The first substrate holder is configured to hold the substrate, is movable within the processing chamber, and is configured to deliver the substrate to the second substrate holder. The second substrate holder is rotatable and configured to hold the substrate while it rotates within and relative to the processing chamber. The liquid application unit is movable relative to the second substrate holder and configured to apply the liquid to the substrate. The control unit is configured to control the rotational speed of the substrate, the position of the liquid application unit, and / or the application rate of the liquid.

[0011] This system allows for the complete surface treatment of a substrate using only a liquid, controlled solely by software-manipulated program parameters. This results in a highly flexible system capable of adapting a substrate surface treatment program to different technical requirements, particularly variations in edge exclusion zones, simply by changing program parameters without any hardware changes (meaning no physical changes to the equipment). Specifically, this system allows for efficient and effective back-side bevel etching / cleaning processes for all the different technical requirements of a modern, high-productivity manufacturing facility.

[0012] Furthermore, the system allows for the precise creation of different edge exclusion zones, preventing defects and / or flaws (such as pin marks) on the edge exclusion zones, or uneven edge exclusion zones around the substrate periphery attributable to a non-centered substrate. Additionally or alternatively, the system can prevent slippage of the substrate that results in inaccurate program parameter control, particularly uncontrolled slippage.

[0013] Furthermore, the system allows for such rapid adjustment of the back bevel etching / cleaning procedure that it is feasible to change one of the back bevel etching / cleaning procedures between substrates simply by adjusting the program parameters selectable through the control unit.

[0014] The first and second substrate holders provide a dual substrate holding and / or processing solution, which allows for high-quality process results and reduces or eliminates the risk of pin marks on edge rejection zones. Furthermore, by providing dual substrate holding, a pre-alignment station may no longer be needed, resulting in a significant reduction in equipment footprint, saving expensive cleanroom space, significantly reducing processing complexity and time, and improving substrate throughput. In summary, this achieves a significant simplification of complexity and a significant reduction in equipment ownership costs.

[0015] Surface treatment of a substrate using a liquid can be preferably performed via a wet chemical process. This wet chemical process can further be a wet chemical etching process and / or a wet chemical cleaning process. In a wet chemical process, various individual process liquids (such as acids, alkalis, oxidants, etc.) and / or mixtures thereof can be used to etch or clean the surface or portions of the substrate. Wet chemical processes offer high chemical selectivity and are easily implemented and scalable to various types and sizes of substrates. Furthermore, wet chemical processes allow for low operating costs.

[0016] Preferably, the system can be a so-called single-wafer processing system, configured to process only one substrate at a time. Furthermore, the system can execute programs sequentially or simultaneously, providing significantly improved program flexibility and control.

[0017] The substrate to be processed can be a silicon wafer or similar, having a diameter or diagonal of up to 300 mm or up to 450 mm or greater.

[0018] The liquid dispensing unit can be configured to dispense a wide variety of liquids and other fluids, such as gases.

[0019] The system can be constructed from a chemically compatible material, such as stainless steel, aluminum, titanium, or plastics, such as polyetheretherketone (PEEK), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), or the like. In this way, the system can provide sufficient rigidity and stability. The material can be additionally coated with a chemically compatible polymer, such as perfluoroalkoxyalkane (PFA), ethylene trifluorochloroethylene copolymer (ECTFE), polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), and the like.

[0020] In one embodiment, the control unit can be configured to control the rotational speed of the substrate, the position of the liquid application unit, and / or the liquid application rate to provide lamella oscillation of the liquid applied to the rotating substrate. The position of the liquid application unit may include a distance between the liquid application unit and the edge of the substrate. Alternatively, the position of the liquid application unit may include a height relative to the substrate.

[0021] Thin-layer oscillations describe a specific oscillation phenomenon in which a thin layer forms and disappears, depending on the liquid application rate, the position of the liquid application unit, and the substrate rotation speed. Furthermore, a surface energy level of the substrate can influence thin-layer oscillations and therefore optimal process parameters, such as the degree of hydrophilicity and / or hydrophobicity, contact angle, etc.

[0022] Controlling the substrate rotation speed, the position of the liquid application unit, and / or the liquid application rate allows for the formation of thin-layer oscillations, which, when correctly formed, support high-quality results in the edge exclusion zone. Experiments have shown that controlling the substrate rotation speed after the liquid application unit position and application rate is advantageous for generating an optimal edge exclusion zone. Controlling the substrate rotation speed, the liquid application unit position, and the liquid application rate provides a particularly accurate and sensitive etching process. Therefore, controlling these parameters together results in a more accurate process compared to controlling each parameter individually.

[0023] In one embodiment, the control unit can be configured to control the dispensing rate of the liquid to provide a continuous flow of liquid. A continuous flow of liquid from the liquid dispensing unit prevents the liquid from dripping in the form of droplets, which could result in unwanted ripple patterns on the edge exclusion zone.

[0024] Thin-layer oscillation allows for the accurate selection of correct software control parameter settings for each incoming wafer without requiring any physical modifications to the system. This prevents time-consuming system readjustments, retesting, and requalification of systems requiring physical modifications. Furthermore, software control parameter settings become crucial, especially in embodiments that simultaneously control the substrate rotation speed, the position of the liquid dispensing unit, and the liquid dispensing rate. Simultaneously controlling these parameters can introduce complexity into the adjustment of thin-layer oscillation, which can be easily handled with software.

[0025] In other words, thin-layer oscillations can be used and / or tuned to achieve high program flexibility, allowing edge exclusion bands to be tuned solely through program parameter control. Furthermore, thin-layer oscillations enable high reproducibility between wafers with the same technical requirements, as well as flexibility between wafers with varying technical requirements.

[0026] In one embodiment, the position control of the liquid dispensing unit may be one of the control methods for an oscillating movement of at least a portion of the liquid dispensing unit between at least two position points.

[0027] This oscillating movement can support the generation or occurrence of a thin layer formation required to achieve good and accurate procedural results.

[0028] In one embodiment, the liquid application unit may include at least one of a first liquid application element disposed at a first substrate holder, a second liquid application element disposed within a second substrate holder, and a third liquid application element disposed at the second substrate holder. Furthermore, at least one liquid application element may be configured to apply a liquid different from the liquid applied by another liquid application element of the liquid application unit. Additionally, at least one liquid application element may be configured to apply other fluids, such as gases.

[0029] A first liquid application element disposed at a first substrate holder can be configured to provide an airflow or apply liquid to one surface (preferably the front side) of the substrate. The first liquid application element can primarily be used to provide an airflow to at least partially protect one surface of the substrate from liquid overflowing from other liquid application elements. Furthermore, the first liquid application element can also be used to apply a rinsing and / or cleaning liquid to rinse and / or clean the substrate. A second liquid application element disposed within a second substrate holder can be configured to apply liquid to another surface (preferably the back side) of the substrate, particularly for cleaning this surface. A third liquid application element disposed at a second substrate holder can be configured to apply liquid for etching and / or cleaning bevels or edges of the substrate. The first, second, and third liquid application units can be disposed independently within the system. For example, for etching / cleaning purposes only, the second and third application elements can be provided without the first liquid application element, or, for example, the activation of the first liquid application element can be deactivated. In another surface treatment step, the first liquid application element can be activated while the activation of the second and third liquid application elements can be deactivated.

[0030] Providing three separate liquid application elements allows for simultaneous back-side bevel etching / cleaning via the second application element for the back side and via the third application element for the bevel, or sequentially, wherein the back side can be processed first and then the bevel, or vice versa. This provides a high degree of flexibility when performing back-side bevel etching / cleaning procedures. In sequential processing, to provide a targeted edge exclusion zone, the third liquid application unit can be operated last after the etching / cleaning of the opposing surfaces of the substrate is completed. Alternatively, the opposing surfaces of the substrate can be etched / cleaned first, and then the bevel or edge of the substrate can be etched / cleaned.

[0031] In one embodiment, the first substrate holder may include fingers that are movable to a closed position to hold the substrate and to an open position to receive or release the substrate.

[0032] The first substrate holder can be configured to rotate with the fingers in both the open and closed positions. By rotating the first substrate holder with the fingers in the open position, pin marks on the substrate can be prevented. Furthermore, the fingers can center the substrate (especially relative to the second substrate holder) and / or move the substrate into the processing chamber. This centering mechanism allows for the processing of substrates with different diameters without requiring a change in equipment, prevents uneven edge exclusion zones or substrate slippage around the substrate periphery, and thereby disables the control of one of the program parameters. The first substrate holder including the fingers can also be referred to as a finger rotor.

[0033] When both the first and second substrate holders are rotatable, the substrate holders can be configured to rotate at the same rotational speed to allow the substrate to be smoothly transferred from one substrate holder to the other substrate holder.

[0034] In one embodiment, the second substrate holder may be a vacuum holder configured to hold the substrate by suction.

[0035] The second substrate holder, as a vacuum holder, can securely hold the substrate in a fixed and centered position by providing a sufficiently strong suction effect, thereby preventing the substrate from sliding, especially uncontrolled sliding.

[0036] In one embodiment, the liquid dispensing unit may include at least one liquid dispensing arm.

[0037] At least one liquid applicator arm may also be referred to as a dielectric arm. The liquid applicator arm may be configured to oscillate continuously between at least two predetermined positions during substrate processing.

[0038] In one embodiment, the system may further include a drying unit for drying one of the substrates.

[0039] After backside etching and / or bevel etching, the substrate can be at least partially rinsed, for example, by applying a rinsing liquid to the substrate using at least one of a liquid application element. After the rinsing process, the substrate can undergo a drying process before being unloaded from the processing chamber.

[0040] According to the present invention, a method for surface treatment of a substrate using a liquid is also provided. The method includes the following steps, not necessarily in the order presented: - Move the first substrate holder, which holds one of the substrates, within a processing chamber. - The substrate is transferred from the first substrate holder to a rotatable second substrate holder. - The substrate held by the second substrate holder is rotated within the processing chamber and relative to the processing chamber. - A liquid is applied to the rotating substrate by a liquid application unit that is movable relative to the second substrate holder, and - Control the rotational speed of one of the substrates, the position of one of the liquid application units, and / or the application rate of one of the liquids.

[0041] According to this method, the substrate can be preferably processed in a region around one edge of the substrate, wherein the substrate can be held in a so-called face-up configuration. The first substrate holder can center the substrate by picking it up. If necessary, the substrate can be exposed to an initial process (e.g., back-side etching) performed before the substrate can be moved into the processing chamber.

[0042] The transfer of the substrate from the first substrate holder to the second substrate holder can preferably be performed without flipping the substrate, allowing the substrate to be processed in an upward configuration.

[0043] The rotational speed at which the substrate held by the second substrate holder can rotate may depend on the individual technical requirements for achieving the desired edge exclusion zone with the required high quality.

[0044] During the application of liquid to the rotating substrate, the front side of the substrate can be physically protected, for example, by holding the first substrate holder in a position very close to the front side of the substrate, preferably within a distance equal to or less than 1 mm.

[0045] In one embodiment, the rotation speed of the substrate, the position of the liquid application unit, and / or the liquid application rate can be controlled to provide thin-layer oscillation of the liquid applied to the rotating substrate.

[0046] Thin-layer oscillation can support achieving good and accurate results regarding edge exclusion zones. Through thin-layer oscillation, the correct software control parameter settings can be correctly selected for each incoming wafer without any physical changes to the system. This avoids time-consuming readjustments, retesting, and requalification of the system due to physical modifications.

[0047] In other words, thin-layer oscillations can be used and / or tuned to achieve high program flexibility, allowing edge exclusion zones to be tuned solely through program parameter control, and achieving high reproducibility between wafers with the same technical requirements and high accuracy flexibility between wafers with different technical requirements.

[0048] In another embodiment, the liquid application unit may include a first liquid application element disposed at the first substrate holder.

[0049] The first liquid application element can be primarily used to provide an airflow to at least partially protect one surface of the substrate from liquid spillage from other liquid application elements. Additionally, the first liquid application element can also be used to apply a rinsing and / or cleaning liquid to rinse and / or clean the substrate.

[0050] According to another embodiment, the method may further include the following steps, not necessarily in the order presented: - The substrate is handed back to the first substrate holder. - Liquid is applied to an area of ​​the substrate previously covered by the second substrate holder using a liquid application unit, and - Control the rotational speed of one of the control substrates, the position of one of the liquid dispensing units, and / or the dispensing rate of one of the liquids.

[0051] Therefore, one surface of the substrate (especially the back side) can be processed to remove any material deposits and / or material layers. By controlling the rotational speed of the substrate, the position of one of the liquid application units, and / or the application rate of the liquid, the program parameters can be adjusted for the required technical standards using only software control.

[0052] In one embodiment, the method may further include rotating the substrate held by the first substrate holder. In one embodiment, the liquid application unit may include a second liquid application element disposed within the second substrate holder.

[0053] If the substrate can be held by the first substrate holder and rotate with the first substrate holder, the second liquid application element can be used to apply a liquid (such as an etching liquid or a cleaning liquid) to the surface of the substrate facing the second liquid application element.

[0054] In one embodiment, the surface treatment may be an etching and / or cleaning process using an etching liquid and / or a cleaning liquid as liquids applied to a rotating substrate.

[0055] Therefore, the substrate can be etched and / or cleaned without changing the processing chamber.

[0056] According to another embodiment, the method may further include rinsing one of the substrates and / or drying one of the substrates.

[0057] In one embodiment, the substrate may include a front side having a functional surface, a back side opposite the front side, and an edge between the front side and the back side. The rotational speed of the substrate, the position of the liquid application unit, and / or the liquid application rate can be controlled to process the edge of the substrate and an edge exclusion zone at the front side and / or the back side of the substrate.

[0058] The edges of a substrate, and edge exclusion zones on the front and / or back sides of the substrate, may be portions of the substrate that fail to enable any function of an electronic device formed by material deposits and / or material layers at least partially constructed on the front side of the substrate. In some cases, the edges, edge exclusion zones, and / or material deposits and / or material layers on the back side of the substrate may even be detrimental to the function of the electronic device. Therefore, material deposits and / or material layers in areas that do not contribute to the functionality of the electronic device can be removed by etching and / or cleaning.

[0059] In one embodiment, the liquid application unit may include a third liquid application element disposed at the second substrate holder, and preferably in an arm-like shape. The third liquid application element may be laterally disposed below the second substrate holder or at substantially the same height as the edge of the substrate. The third liquid application unit may be configured to deliver the process liquid directly onto the substrate to ensure high-accuracy surface cleaning / etching. The third liquid application element may be movable relative to the second substrate holder, allowing it to move closer to or further away from the second substrate holder to adjust the amount of liquid reaching the substrate. The third liquid application element may also be moved during a surface treatment (e.g., gradually moving away from the substrate holder).

[0060] The third liquid application element may also be referred to as a dielectric arm. The dielectric arm may be configured to oscillate continuously between at least two predetermined positions during substrate processing and to apply liquid to at least one edge of the rotating substrate.

[0061] In another embodiment, edges, edge exclusion zones, and / or back sides can be processed simultaneously or sequentially. This allows for a high degree of flexibility when performing surface treatment procedures.

[0062] In one embodiment, the controlled position of the liquid application unit may include a distance between the liquid application unit and the edge of the substrate. This allows for the formation of thin-layer oscillations, which, when correctly formed, support achieving high-quality results in the edge exclusion zone.

[0063] In one embodiment, the rotational speed of the substrate, the position of the liquid application unit, and / or the liquid application rate can be controlled to process an edge exclusion zone with a width between 0.2 mm and 12 mm (preferably 0.5 mm to 9 mm).

[0064] According to another embodiment, the method may further include protecting an untreated area on the front side of the substrate by means of a first substrate holder and / or an airflow provided by a first liquid application element.

[0065] Therefore, a so-called active area can be protected from chemical spills during etching and / or cleaning of the back side and / or edges of the substrate. The active area is a region on the front side of the substrate that is part of the electronic device.

[0066] In another embodiment, the method may further include rotating and centering the substrate relative to the second substrate holder by means of the first substrate holder.

[0067] This allows for fail-safe rotational centering of one of the substrates, thereby enabling the formation of a substantially homogeneous and substantially uniform edge exclusion zone around the substrate.

[0068] In one embodiment, the method may further include rotating the first substrate holder while rotating the substrate in the second substrate holder. Therefore, the first substrate holder may allow protection of the surface of the substrate facing the first substrate holder from chemical spills. In this embodiment, the first and second substrates preferably rotate in the same direction. The first and second substrate holders may rotate at different speeds. Preferably, during the rotation of the first and second substrate holders, process fluid is prevented from escaping from the first substrate holder.

[0069] In another embodiment, the substrate can be disposed between the first substrate holder and the second substrate holder at a rotational speed in the range of 0 rpm to 700 rpm (especially in the range of 20 rpm to 600 rpm).

[0070] In one embodiment, the substrate can be maintained in orientation (preferably front-up) relative to the processing chamber at various points during the surface treatment process. By eliminating the need to rotate the wafer during surface treatment, the complexity of the equipment can be significantly reduced. Furthermore, alignment with liquid application elements can be significantly simplified, and the risk of substrate damage can be reduced. Additionally, the cost of the system capable of performing the described method can be significantly reduced. Therefore, substrate processing can be significantly simplified and costs reduced.

[0071] In one embodiment, the control used to provide thin-film oscillation (specifically, software control) can be simply adjusted for different surface treatment requirements, specifically without the need for tool replacement.

[0072] Therefore, a single software control enables complete control over program parameters, high flexibility, and an improved back-side bevel etching / cleaning process without the need for time- and / or cost-intensive tool changes.

[0073] According to the present invention, a computer program element for a system employing a liquid for surface treatment of a substrate is also provided. When executed by a processing element, the computer program is adapted to perform the steps of one of the method embodiments described above.

[0074] It should be understood that the systems, methods, and computer program elements according to the independent claims have similar and / or identical preferred embodiments, specifically as defined in the appendix claims. Furthermore, it should be understood that one preferred embodiment of the invention may also be any combination of the appendix claims and the respective independent claims.

[0075] These and other aspects of the invention will be understood from the embodiments described below and will be illustrated with reference to the embodiments described below. Simple Explanation of the Diagram

[0076] Exemplary embodiments of the invention will be described below with reference to the accompanying drawings: Figures 1a and 1b schematically and illustratively show a substrate before (a) and after (b) a back-side bevel etching / cleaning process according to the present invention; Figures 2a and 2b schematically and illustratively show two substrate geometries according to SEMI standards; Figure 3 schematically and illustratively shows one of the edge exclusion zones constructed according to the present invention; Figure 4 schematically and illustratively illustrates a system according to the present invention for surface treatment of a substrate using a liquid in a loading / unloading position; Figure 5 schematically and illustratively illustrates a system according to the present invention for surface treatment of a substrate using a liquid in a processing configuration for bevel etching; Figure 6 schematically and illustratively illustrates a system for surface treatment of a substrate using a liquid in a processing configuration for backside etching and cleaning according to the present invention; Figures 7a and 7b schematically and illustratively illustrate the thin-layer oscillation according to the present invention, wherein Figure 7a shows a desired thin-layer formation and Figure 7b shows an undesired state of thin-layer fracture; and Figure 8 schematically and illustratively illustrates a method according to the present invention for surface treatment of a substrate using a liquid. Implementation

[0077] Figure 1a schematically and illustratively shows a substrate 1 having a material layer 2 deposited over its entire surface (i.e., a front side 3, an edge 4, and a back side 5). The substrate 1 may be a substantially circular silicon wafer with a diameter of about 300 mm or greater. Alternatively, a substrate with a diameter less than 300 mm may also be used. The material layer 2 is configured to construct an electronic device only on the front side 3 of the substrate 1. The electronic device does not require the material layer 2 on the edge 4 and the back side 5, and in some cases, the material layer 2 on the back side 5 and the edge 4 may even be detrimental to the function of the electronic device. Therefore, it is necessary to remove portions of the material layer 2 that are not required for constructing the electronic device.

[0078] Figure 1b schematically and illustratively shows a substrate 1 on which material layer 2 has been removed from all portions of the substrate 1, where material layer 2 does not contribute to the function of an electronic device. A procedure for removing material layer 2 from all portions of the substrate 1 (on which material layer 2 does not contribute to a function) is called a back-side bevel etching / cleaning procedure.

[0079] Therefore, in Figure 1b, material layer 2 has been removed from the back side 5, edge 4, and a small radial portion near edge 4 on the front side 3. This radial portion is referred to as an edge exclusion zone 6. The edge exclusion zone 6 is a region on the front side 3 and edge 4 that cannot be used to produce functional electronic devices. The edge exclusion zone 6 needs to fully meet the technical requirements of the constructed electronic device, and the edge exclusion zone 6 must be reproducible between wafers of the same technology. The edge exclusion zone 6 can extend from 0 mm to 8 mm in the radial direction, preferably from 0 mm to 5 mm. The transition from the remaining material layer 2 on the front side 3 of the substrate 1 to the edge exclusion zone 6 is formed by a new material edge 7.

[0080] Figures 2a and 2b schematically and illustratively illustrate two substrate geometries commonly used for constructing electronic devices according to Semiconductor Equipment and Materials International (SEMI) standards. Figure 2a shows a so-called "blunt-nose wafer" 8 formed as a substrate 1 that is essentially a circular wafer with a rounded edge 4. The blunt-nose wafer 8 includes a smooth transition from a flat wafer surface (i.e., the front side 3 and the back side 5) to one of the edges 4. The rounded edge 4 can be divided into five segments: a transition region 13 from the front side 3 to one of the edges 4, a front rounded region 12, a crown or apex 11, a back rounded region 10, and a transition region 9 from the back side 5 to one of the edges 4.

[0081] Figure 2b shows a so-called "bullet-shaped wafer" 14 formed as a substantially circular wafer of a substrate 1 having a beveled edge 4. The beveled edge 4 can be formed by a so-called "bevel grinding process" having an angle of substantially 22 degrees with the main surfaces of the substrate 1 (i.e., the front side 3 and the back side 5). The beveled edge 4 can be divided into five sections: a transition region 13 from the front side 3 to the edge 4, a front beveled region 16, a crown or apex 11, a back beveled region 15, and a transition region 9 from the back side 5 to the edge 4.

[0082] Figure 3 schematically and illustratively shows the edge exclusion zone 6 constructed according to the present invention. After a back-side bevel etching / cleaning process, the front side 3 of the substrate 1 includes an edge exclusion zone 6 having an extended width "ew" in the radial direction. The edge exclusion zone 6 is formed around the substrate 1, with a new material edge 7 forming a smooth, continuous transition from the edge exclusion zone 6 to the material layer 2 on the front side 3.

[0083] Figures 4 to 6 schematically and illustratively illustrate a system 17 for surface treatment of a substrate 1 using a liquid according to the present invention in different configurations, wherein Figure 4 shows a loading / unloading configuration, Figure 5 shows a processing configuration for bevel etching, and Figure 6 shows a processing configuration for backside etching and cleaning.

[0084] System 17 is configured as a so-called single-wafer processing system for processing only one substrate 1 at a time. The substrate 1 to be processed in system 17 may be a substantially circular silicon wafer having a diameter of up to 300 mm or greater. System 17 includes a first substrate holder 18 and a second substrate holder 19. The first substrate holder 18 is configured to hold the substrate 1 and is movable within a processing chamber 20 (particularly in a vertical direction 26). Furthermore, the first substrate holder 18 is rotatable within the processing chamber 20 and is configured to deliver the substrate 1 to the second substrate holder 19 inside the processing chamber 20. The second substrate holder 19 is configured to be fixed but rotatable within the processing chamber 20 and is further configured to hold the substrate 1 while it is rotating within and relative to the processing chamber 20.

[0085] Furthermore, system 17 can be configured to process substrate 1 in a face-up configuration (see also FIG5). This means that the front side 3 of substrate 1 is guided upward, so that it is positioned toward the first substrate holder 18 and the back side 5 of substrate 1 is guided toward the second substrate holder 19.

[0086] System 17 further includes a liquid dispensing unit 21 for dispensing a liquid onto a substrate 1 inside the processing chamber 20 and a control unit 22. The control unit 22 is configured to control a rotational speed of the substrate 1, a position of the liquid dispensing unit 21, and / or a dispensing rate of the liquid dispensed by the liquid dispensing unit 21. The liquid dispensing unit 21 is movable relative to the second substrate holder 19. Furthermore, according to the exemplary embodiment shown in Figures 4 to 6, the liquid dispensing unit 21 includes a first liquid dispensing element 23, a second liquid dispensing element 24, and a third liquid dispensing element 25.

[0087] A first liquid application element 23 is disposed at a first substrate holder 18 and configured to apply a liquid or gas flow to an upwardly directed surface of the substrate 1 (typically the front side 3 of the substrate 1). A second liquid application element 24 is disposed inside a second substrate holder 19 and configured to apply a liquid to a downwardly directed surface of the substrate 1 for etching and / or cleaning this surface (typically the back side 5 of the substrate 1). A third liquid application element 25 is disposed at the second substrate holder 19, preferably laterally below the second substrate holder 19, and configured to apply a liquid to an edge 4 of the substrate 1 for etching and / or cleaning the edge 4 of the substrate 1. In a preferred embodiment, the third liquid application element 25 is a liquid application arm whose position can be controlled by a control unit 22.

[0088] An illustrative processing sequence may be as follows: For example, a robotic arm (not shown) delivers substrate 1 to a first substrate holder 18. The first substrate holder 18 includes at least two fingers (not shown) that are movable to a closed position to hold substrate 1 and to an open position to receive or release substrate 1. Therefore, the first substrate holder 18 may also be referred to as a finger rotor. By taking over substrate 1 from the robotic arm, the first substrate holder 18 automatically centers substrate 1 and moves substrate 1 into processing chamber 20 (see Figure 4). Inside processing chamber 20, the first substrate holder 18 delivers substrate 1 to a second substrate holder 19 without flipping substrate 1 (see Figure 5). The handling of substrate 1 between the first substrate holder 18 and the second substrate holder 19 can be performed at a rotational speed in the range of 0 rpm to 700 rpm, and particularly in the range of 20 rpm to 600 rpm.

[0089] The second substrate holder 19 is configured to hold the substrate 1 by suction, and therefore can also be referred to as a vacuum holder. The second substrate holder 19 can generate a sufficiently strong suction force to hold the substrate 1 firmly in a central position and prevent any unwanted and / or uncontrolled sliding of the substrate 1. Figure 5 illustrates the processing configuration of the system 17 after the substrate 1 has been transferred from the first substrate holder 18 to the second substrate holder 19. In this position, the edge 4 of the substrate 1 is etched and / or cleaned (the so-called bevel etching process). The control unit 22 selects program parameters according to the requirements of the selected technology to achieve the edge exclusion zone 6 that meets the requirements for accuracy of radial extension width ew and quality of edge exclusion zone 6.

[0090] The main program parameters controlled by the control unit 22 to achieve the desired edge exclusion zone 6 are the rotational speed (revolutions per minute) of one of the substrates 1, the position of the liquid application unit 21 (especially the position of the third liquid application element 25 relative to the edge 4 of the substrate 1), and the liquid application rate through the third liquid application element 25. Controlling the position of the liquid application unit 21 includes controlling an oscillating movement of at least a portion of the liquid application unit 21 between at least two positions. The control unit 22 is configured to control at least these parameters to provide so-called thin-film oscillation (see also Figures 7a and 7b). Thus, the system 17 allows an edge exclusion zone 6 with an extension width ew between 0.2 mm and 12 mm (preferably 0.5 mm to 9 mm) to be achieved solely by controlling the software program parameters.

[0091] During the bevel etching process, the substrate 1 is rotated at a predetermined rotational speed controlled by the control unit 22 by the second substrate holder 19, and at least the third liquid application element 25 applies a liquid to a region of the edge 4. The liquid may be a chemical solution configured to remove material deposits and / or material layer 2 (see FIG. 1) from the edge 4 region, such as an etching liquid. The control unit 22 controls the position of the liquid application unit 21 by controlling an oscillating movement of at least a portion of the liquid application unit 21 between at least two positions and / or controlling a distance between the liquid application unit 21 and the edge 4.

[0092] The front side 3 of the substrate 1 is physically protected to prevent spillage of liquid applied by the third liquid application element 25 to a functional area of ​​the substrate 1, which is a functional area of ​​the electronic device. Preferably, the front side 3 of the substrate 1 is protected by holding the first substrate holder 18 in a very close position (e.g., equal to or less than 1 mm) on the front side 3 of the substrate 1.

[0093] Additionally, the first liquid dispensing element 23 dispenses an airflow (e.g., nitrogen flow) to create an airflow curtain between the first substrate holder 18 and the front side 3 of the substrate 1. The control unit 22 can controllably adjust the physical protection through the first substrate holder 18 and the airflow to protect the required edge exclusion zone 6, especially the portion of the edge exclusion zone 6 extending to the front side 3 of the substrate 1, from the effects of chemical spillage.

[0094] Therefore, it is necessary to adjust the position of the first substrate holder 18 and the airflow relative to the front side 3 of the substrate 1 so that only the active area on the front side 3 of the substrate 1 is protected.

[0095] During the bevel etching process, the first substrate holder 18 is preferably in the open position to prevent pinholes or fingerprints from forming in the edge exclusion zone 6. The first substrate holder 18 may rotate at the same or different rotational speed as the second substrate holder 19. Alternatively, the first substrate holder 18 may rotate at a time-dependent variable speed. If necessary, after the bevel etching process is completed, a brief rinsing procedure may be performed, for example, with deionized (DI) water to clean chemical residues in the edge exclusion zone 6.

[0096] After the bevel etching process is completed, the first substrate holder 18 picks up the substrate 1 again by closing the fingers surrounding the substrate 1, and lifts the substrate 1 away from the second substrate holder 19 to bring the substrate 1 to a position for performing a back-side etching / cleaning process within the processing chamber 20 (see FIG. 6) for etching and / or cleaning an area of ​​the substrate 1 previously covered by the second substrate holder 19. In the position shown in FIG. 6, the back-side etching / cleaning process is performed on the back side 5 of the substrate 1. The front side 3 of the substrate 1 is protected by the first substrate holder 18 in the closed position holding the substrate 1 and an airflow entity providing an air curtain, while at least the second liquid application element 24 applies a liquid (e.g., a chemical solution) to the back side 5 of the substrate 1.

[0097] The control unit 22 selects or controls program parameters (especially the rotational speed of the substrate 1 and therefore the first substrate holder 18, the position of at least the second liquid application element 24, and the liquid application rate) to remove material deposits and / or material layer 2 from the back side 5 of the substrate 1. After the back side etching process is completed, a final rinsing and drying process is performed to remove any chemical residues from the substrate 1. Therefore, the liquid application unit 21 can apply a cleaning liquid to the substrate 1, and the system 17 may further include a drying unit (not shown) configured to dry the substrate 1.

[0098] After this, the processing sequence is completed, and the first substrate holder 18 moves the substrate 1 out of the processing chamber 20 to a position where a robotic arm (not shown) can pick up the processed substrate 1 to transport the substrate 1 to the next station.

[0099] Variations in the processing sequence are possible. For example, in some processing sequences, an initial procedure, such as a back-side etching procedure, may be performed on the substrate 1 before it is moved into the processing chamber 20. In some processing sequences, a suitable rinsing procedure, such as using DI water, may be performed on the front side 3 of the substrate 1 before and after it is handed over from the first substrate holder 18 to the second substrate holder 19. Furthermore, in certain cases, any other sequence of the substrate 1's handling and / or rinsing procedures may be beneficial in achieving the desired results. In addition, the bevel etching procedure and the back-side etching procedure may be performed sequentially or simultaneously as illustrated above.

[0100] Therefore, system 17 allows the removal of material deposits and / or material layers 2 from areas on substrate 1 where the material deposits and / or material layers 2 do not perform any function and / or may be harmful, while achieving a precise edge exclusion zone 6 by adjusting program parameters for different surface treatment requirements only through software control (i.e., control unit 22), without replacing hardware such as equipment, tools and the like.

[0101] Figures 7a and 7b schematically and illustratively illustrate the thin-layer oscillation according to the present invention, wherein Figure 7a shows a desired thin-layer formation and Figure 7b shows an undesired state of thin-layer fracture.

[0102] A thin layer 27 is formed when a liquid is applied to a rotating surface. A specific oscillation of thin layer formation and disappearance can be observed depending on the liquid flow rate, at least one liquid application location (meaning the position of a liquid application unit relative to the rotating substrate 1), and the rotational speed of the substrate 1. Furthermore, it has been observed that an energy level of the surface of the substrate 1 on which the liquid is applied has a significant impact on thin layer formation and therefore on the selection of process parameters for achieving optimal results. An energy level of a surface has a significant impact on the hydrophilic or hydrophobic properties of the surface; this means that the energy level of the surface affects the contact angle formed by the liquid contacting the surface. Process parameters affected by the surface energy level may include the liquid application or flow rate, the rotational speed of the surface, the movement of the liquid application arm, and the like.

[0103] Figure 7a depicts the formation of a thin layer 27 of liquid, which supports the achievement of a good procedural result, and Figure 7b shows an undesirable state in which a thin layer 27 of liquid breaks or disappears.

[0104] Figure 8 schematically and illustratively illustrates a method 100 according to the present invention for surface treatment of a substrate 1 using a liquid. In step S1, a first substrate holder 18 holding the substrate 1 is moved into a processing chamber 20. In step S2, the substrate 1 is transferred from the first substrate holder 18 to a second substrate holder 19. In step S3, the substrate 1 held by the second substrate holder 19 is rotated within the processing chamber 20 and relative to the processing chamber 20. In step S4, a liquid is applied to the rotating substrate 1 by a liquid application unit 21. The liquid application unit 21 is at least partially movable relative to the second substrate holder 19. In step S5, the method 100 further includes controlling the rotational speed of the substrate 1, the position of the liquid application unit 21, and / or the application rate of the liquid.

[0105] 1:Substrate 2: Material layer 3: Front side 4: Edge 5: Back side 6: Edge Exclusion Zone 7: Edge of New Materials 8: Blunt-tip wafers 9: Transition Zone 10: Rear side repaired circular area 11: Vertex 12: Front side repaired circular area 13: Transition Zone 14: Bullet-shaped wafer 15: Backside sloping area 16: Front sloping area 17: System 18: First substrate holder 19: Second substrate holder 20: Processing Chamber 21: Liquid dispensing unit 22: Control Unit 23: First liquid dispensing element 24: Second liquid dispensing element 25: Third liquid dispensing element 26: Up and down direction 27: Thin layer 100: Method ew: Extended width S1: Steps S2: Steps S3: Steps S4: Steps S5: Steps

Claims

1. A system (17) for surface treatment of a substrate (1) using a liquid, comprising: The system comprises a first substrate holder (18), a second substrate holder (19), a liquid dispensing unit (21), a processing chamber (20), and a control unit (22), wherein the first substrate holder (18) is configured to hold the substrate (1), wherein the first substrate holder (18) is movable within the processing chamber (20) and configured to deliver the substrate (1) to the second substrate holder (19), wherein the second substrate holder (19) is rotatable and configured to hold the substrate (1) during rotation of the substrate (1) within and relative to one of the processing chambers (20). The liquid application unit (21) is movable relative to the second substrate holder (19) and configured to apply the liquid to the substrate (1). The control unit (22) is configured to control a rotational speed of the substrate (1), a position of the liquid application unit (21), and / or a liquid application rate. The first substrate holder (18) includes finger-like portions that are movable to a closed position to hold the substrate (1) and to an open position to receive or release the substrate (1).

2. The system (17) of claim 1, wherein the first substrate holder (18) is configured to rotate about the same axis as the second substrate holder (19).

3. As in system (17) of request item 1, wherein: When the substrate (1) is held by the first substrate holder (18) before being handed over to the second substrate holder (19), the fingers are configured to be in the closed position, and when the substrate (1) is handed over to the second substrate holder (19) and / or during a bevel etching process for processing one edge (4) of the substrate (1), the fingers are configured to be in the open position.

4. The system (17) of claim 1, wherein the control unit (22) is configured to control the rotation speed of the substrate (1), the position of the liquid application unit (21) and / or the application rate of the liquid to provide thin-layer oscillation of the liquid applied to the rotating substrate (1).

5. The system (17) of claim 1, wherein the control of the position of the liquid dispensing unit (21) is a control of an oscillating movement of at least a portion of the liquid dispensing unit (21) between at least two position points.

6. The system (17) of claim 1, wherein the liquid application unit (21) includes at least one of a first liquid application element (23) disposed on the first substrate holder (18), a second liquid application element (24) disposed inside the second substrate holder (19), and a third liquid application element (25) disposed on the second substrate holder (19).

7. The system (17) of claim 1, wherein the first substrate holder (18) is configured to be rotatable.

8. The system (17) of claim 1, wherein the first substrate holder (18) is configured to rotatably center the substrate (1) relative to the second substrate holder (19).

9. The system (17) of claim 1, wherein the second substrate holder (19) is a vacuum holder configured to hold the substrate (1) by suction.

10. The system (17) of claim 1, wherein the liquid dispensing unit (21) includes at least one liquid dispensing arm.

11. The system (17) of claim 1, further comprising a drying unit for drying the substrate (1).

12. A method (100) for surface treatment of a substrate (1) using a liquid, comprising: A first substrate holder (18) holding a substrate (1) is moved in a processing chamber (20) to transfer the substrate (1) from the first substrate holder (18) to a rotatable second substrate holder (19), and the substrate (1) held by the second substrate holder (19) is rotated in the processing chamber (20) and relative to the processing chamber (20). A liquid is applied to the rotating substrate (1) by a liquid application unit (21) movable relative to the second substrate holder (19), and a rotational speed of the substrate (1), a position of the liquid application unit (21) and / or a liquid application rate are controlled. The first substrate holder (18) includes finger-like portions that are movable to a closed position to hold the substrate (1) and to an open position to receive or release the substrate (1).

13. The method (100) of claim 12, wherein the rotational speed of the substrate (1), the position of the liquid application unit (21) and / or the application rate of the liquid are controlled to provide thin-layer oscillation of the liquid applied to the rotating substrate (1).

14. The method (100) of claim 12, wherein the liquid application unit (21) includes a first liquid application element (23) disposed on the first substrate holder (18).

15. The method (100) of claim 12, further comprising: The substrate (1) is handed back to the first substrate holder (18), and the liquid is applied to a region of the substrate (1) previously covered by the second substrate holder (19) by the liquid application unit (21), and the rotation speed of the substrate (1), the position of the liquid application unit (21) and / or the application rate of the liquid are controlled.

16. The method (100) of claim 12 further includes rotating the substrate (1) held by the first substrate holder (18).

17. The method (100) of claim 12, wherein the liquid application unit (21) includes a second liquid application element (24) disposed inside the second substrate holder (19).

18. The method (100) of claim 12, wherein the surface treatment is performed by using an etching liquid and / or a cleaning liquid as an etching and / or cleaning of the liquid applied to the rotating substrate (1).

19. The method (100) of claim 12 further includes a rinsing for rinsing the substrate (1) and / or a drying for drying the substrate (1).

20. The method (100) of claim 12, wherein the substrate (1) includes a front side (3) having a functional surface, a back side (5) opposite to the front side (3) and an edge (4) between the front side (3) and the back side (5), wherein the rotational speed of the substrate (1), the position of the liquid dispensing unit (21) and / or the dispensing rate of the liquid are controlled to process the edge (4) of the substrate (1) and an edge exclusion zone (6) at the front side (3) and / or the back side (5) of the substrate (1).

21. The method (100) of claim 20, wherein the liquid application unit (21) includes a third liquid application element (25) disposed on the second substrate holder (19) and preferably in an arm shape.

22. The method (100) of claim 20, wherein the edge (4), the edge exclusion zone (6) and / or the back side (5) are processed simultaneously or sequentially.

23. The method (100) of claim 20, wherein the controlled position of the liquid application unit (21) includes a distance between the liquid application unit (21) and the edge (4) of the substrate (1).

24. The method (100) of claim 20, wherein the rotational speed of the substrate (1), the position of the liquid application unit (21) and / or the application rate of the liquid are controlled to process the edge exclusion zone (6) of a width (ew) between 0.2 mm and 12 mm, preferably between 0.5 mm and 9 mm.

25. The method (100) of claim 14 or 20 further includes protection of an untreated area on the front side (3) of the substrate (1) by an airflow provided by the first substrate holder (18) and / or by the first liquid application element (23).

26. The method (100) of claim 12 further includes rotating the substrate (1) relative to the second substrate holder (19) by one of the first substrate holders (18).

27. The method (100) of claim 12 further includes rotating one of the first substrate holders (18) during the rotation of the substrate (1) in the second substrate holder (19).

28. The method (100) of claim 12, wherein the treatment of the substrate (1) between the first substrate holder (18) and the second substrate holder (19) is performed at a rotational speed in the range of 0 rpm to 700 rpm.

29. The method (100) of claim 12, wherein the orientation of the substrate (1) relative to the processing chamber (20) is maintained at each point in the method (100) for surface treatment, preferably front-side up.

30. The method (100) of claim 13, wherein the control for providing thin-layer oscillation, specifically, is a software control that is only adapted to different surface treatment requirements, specifically, without the need for tool replacement.

31. A computer program element for a system (17) for surface treatment of a substrate (1) using a liquid, which, when executed by a processing element, is adapted to perform the steps of any one of method claims 12 to 30.

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