System and method for wet chemical treatment of a substrate surface

Abstract

The present disclosure relates to a system for wet chemical processing of a substrate surface and a method for wet chemical processing of a substrate surface. The system for wet chemical processing of a substrate surface comprises a radiation source configured to provide a first electromagnetic radiation. The system further comprises a dispensing body comprising at least a spray orifice, wherein the spray orifice is configured to dispense a wet chemical with respect to the substrate surface. The system further comprises at least one waveguide module, wherein the waveguide module is configured to guide the first radiation from the radiation source through the dispensing body. The system further comprises a sensor element configured to detect a second radiation, which is a reflected radiation of the first radiation at the substrate surface. The waveguide module is further configured to guide the second radiation through the dispensing body and to the sensor.

Description

Technical Field

[0001] This disclosure relates to a system for wet chemical treatment of a substrate surface and a method for wet chemical treatment of a substrate surface. Background Technology

[0002] Many industrial processes, especially in the highly complex semiconductor industry where atomic precision is paramount, require the ability to stop processing precisely (and sometimes abruptly) at very specific times. In most cases, this timing depends on whether material is grown on a substrate surface, partially removed (thinned) to a specific layer thickness, or completely removed from the substrate surface. The substrate surface can be completely covered by the target material layer or have localized structures, meaning it is not completely covered or covered by (regular or irregular) patterns. Achieving highly accurate stopping of such processes typically requires near-atomic-scale thickness control, and currently, thickness control in the nanometer range is more common. Many industries typically employ a timing approach. That is, the time when the process must be stopped is determined experimentally, and then the process is controlled with the most stringent specifications possible. However, particularly in material removal processes (such as etching)—where only precisely limited amounts of material are allowed to be removed—even minute fluctuations in chemical concentration or temperature can lead to very serious and unacceptable consequences. In these cases, accurate process endpoint control can only be achieved with the aid of highly accurate endpoint detection systems. In particular, the endpoint detection system must be compatible with the chemicals being processed, because in most cases, very harsh chemical environments are required so that the chemical environment does not cause the endpoint detection signal to deviate.

[0003] Endpoint detection methods in etching processes are well-known. Some of these methods are based on laser interferometry or optical emission spectroscopy, which monitor the interference phenomenon caused by light reflected from the thin film during etching, or monitor the light emission signal, respectively. These methods employ similar technical principles but use different light sources. Laser interferometry uses a laser beam, such as a helium-neon laser, as the light source, while optical emission spectroscopy uses the plasma emitted from a plasma reaction chamber as the light source.

[0004] However, these known endpoint detection systems are only applicable to dry etching processes, such as plasma etching or reactive ion etching. If these systems are used in wet etching processes employing liquid chemicals (acids, alkalis, oxidants, etc.), the signal source and detection system are set at a predetermined distance from the liquid surface, requiring the wet etchant layer to have a constant thickness to suppress unwanted interference effects. Such systems require so-called horizontal chemical spin-coating systems to adjust the spin-coating speed according to the liquid viscosity, thereby controlling the thickness and shape of the liquid chemical layer. In one example, an etching apparatus is used to process a substrate carrying one or more films to be etched, using an etching solution to remove one or more layers of film from only one side (front or back) of the substrate. This apparatus is used to remove film from one side of the substrate (such as a silicon wafer), targeting either the back or front side. The wet etchant stream is delivered to the wafer-facing side; by rotating the wafer, a wet etchant film of uneven thickness is formed. The incident beam will be partially reflected at the air-liquid thin film interface, the liquid-solid thin film interface, and the solid thin film-substrate interface; these effects must be compensated for through challenging physical assumptions and mathematical models. Summary of the Invention

[0005] Therefore, it may be necessary to provide an improved system and method for wet chemical treatment of substrate surfaces to make it easier to control the wet chemical treatment of substrate surfaces.

[0006] The objective of this disclosure is achieved through the content of the independent claims, with further embodiments described in the dependent claims. It should be noted that the aspects of this disclosure described below are applicable to both systems and methods for wet chemical treatment of substrate surfaces.

[0007] According to this disclosure, a system for wet chemical treatment of a substrate surface is provided. The system includes a radiation source configured to provide first electromagnetic radiation. The system also includes a dispenser having at least one injection orifice configured to dispense wet chemicals relative to the substrate surface. The system further includes at least one waveguide module configured to guide the first radiation from the radiation source through the dispenser. The system also includes a sensor element configured to detect second radiation, which is reflected radiation from the first radiation at the substrate surface. The waveguide module is further configured to guide the second radiation through the dispenser and to the sensor element.

[0008] This structure allows the system of this disclosure for wet chemical treatment of substrate surfaces to eliminate the need for predetermined distances as described in the prior art section between the wet chemical surface and the radiation source, and between the wet chemical surface and the sensor element. Compared to the prior art, this disclosure ensures a constant wet chemical layer thickness without requiring the radiation source and sensor element to be far from the wet chemical surface, thereby suppressing unwanted interference effects. Therefore, the system of this disclosure for wet chemical treatment of substrate surfaces can control the wet chemical layer by adjusting the spin coating speed according to the viscosity of the wet chemical without using the aforementioned horizontal chemical spin coating system. Furthermore, this disclosure also eliminates the need for the aforementioned complex physical assumptions and mathematical models. The second radiation provides information about the substrate surface and can serve as the basis for controlling the wet chemical treatment of the substrate surface. Thus, this disclosure provides an improved system for wet chemical treatment of substrate surfaces, making it easier to control the wet chemical treatment of the substrate surface. Surprisingly, this can be achieved simply by using existing dispensing bodies to guide the first and second radiations.

[0009] Wet chemical processing can be material removal (e.g., etching) or material deposition (e.g., electroplating). Wet chemicals can be etchants and / or electrolytes. The substrate can be a wafer, panel, etc. The substrate surface can be the wafer surface.

[0010] The radiation source can be a light-emitting diode (LED) or a halogen lamp. The first electromagnetic radiation provided can be light, especially a beam of light. The first electromagnetic radiation can have a single wavelength, multiple wavelengths, or include a spectrum. The second electromagnetic radiation (i.e., the reflected radiation of the first radiation at the substrate surface) is also subject to the same principle.

[0011] The dispenser contains at least several injection holes. These injection holes control the flow of wet chemicals to the substrate surface. The injection holes may have a structure or shape to increase the flow rate of the wet chemicals, such as nozzles or tips. The number of injection holes can reach 100 or more. The injection holes can spray the wet chemicals perpendicular to the main surface of the dispenser. The main surface of the dispenser can be understood as the surface facing the substrate when processing it.

[0012] The injection orifice typically supplies liquid from the internal space of the dispensing body (i.e., the so-called dispensing volume). Therefore, the injection orifice connects the internal space of the dispensing body to the space between the dispensing body and the surface of the substrate to be treated. The injection orifice may extend partially through (rather than along) the dispensing body. The injection orifice can spray wet chemicals perpendicularly onto a cross-section of the dispensing body. This cross-section can be understood as being parallel to the main surface of the dispensing body.

[0013] The waveguide module can form part of the distribution body. The sensor element can be understood as a signal receiver, such as a spectrometer. The second radiation received by the sensor element can provide information about the substrate surface (surface property data) and can serve as a basis for controlling the wet chemical treatment of the substrate surface. Alternatively, this can be done by comparing the first and second radiations.

[0014] In some embodiments, wet chemical processing is an etching process. The wet chemicals can be etchants. The sensor element can also be configured to analyze surface property data of the substrate surface provided by at least a second radiation to determine the end of the etching process. Thus, a system for determining the end point of a wet chemical etching process can be provided without the need for complex and difficult control of the wet chemical layer thickness. On the substrate surface, the wet chemicals alter the surface composition and / or layer thickness, thereby affecting the reflection of the first radiation (referred to as the second radiation). In this process-dependent process, the reflected signal can be guided to the sensor element via a waveguide module; this element can detect and analyze the surface property data (e.g., material properties and / or thickness-related information) contained in the reflected first radiation (i.e., the second radiation), thereby enabling in-situ, real-time interpretation of the process state. Thus, a high-precision end-point detection system for material removal (e.g., etching) processes can be constructed, ensuring that only a precisely defined amount of material is removed.

[0015] In some embodiments, the first radiation and / or the second radiation are guided through a transparent or translucent portion of the dispenser. This avoids the use of additional components and / or saves space. At least one transparent or translucent portion of the dispenser, or most or all of the dispenser, may be made of a material capable of at least partially transmitting radiation of a specific wavelength or multiple wavelengths, or transmitting an electromagnetic spectrum in the wavelength range of 100 nm to 2000 nm (preferably 200 nm to 1500 nm, more preferably 300 nm to 1000 nm, and even more preferably 400 nm to 750 nm). At least a portion of these wavelength ranges may be transmitted. At least one transparent or translucent portion of the dispenser, or most or all of the dispenser, may be made of a transparent or translucent plastic material. This transparent or translucent plastic material may be a transparent or translucent polymer material, preferably a transparent or translucent PMMA (polymethyl methacrylate) material. At least one transparent or translucent portion of the dispenser, or most or all of the dispenser, may be considered as part of a waveguide module.

[0016] A transparent or semi-transparent portion (possessing the aforementioned characteristics) of the distributor is used to guide the first radiation and / or the second radiation. This portion can be a tubular or tower-shaped section of the distributor. In other words, when viewed in cross-section, the waveguide module may include a tubular or tower-shaped portion of the distributor. This cross-section can be understood as parallel to the main surface of the distributor. The tubular portion of the distributor may form a connecting channel for guiding the first radiation from the radiation source through the distributor (and to the substrate surface, if present), and / or guiding the second radiation (from the substrate surface, if present) through the distributor to the sensor element.

[0017] In some embodiments, the first radiation and / or the second radiation is guided through guide holes on the distributor. This simplifies the guidance of the first and / or second radiation through the distributor. The guide holes can be configured to pass through a transparent or semi-transparent portion of the distributor. Alternatively, guide holes can be used instead of transparent or semi-transparent portions of the distributor. The guide holes can be considered part of the waveguide module. There can be one or more guide holes. A first guide hole for the first radiation and a second guide hole for the second radiation can be provided. Multiple guide holes can be provided to increase the amount of radiation transmitted.

[0018] The guide aperture can also be configured to cooperate with one or more tubular or tower-shaped sections of the distribution body. Specifically, the guide aperture can be surrounded by several or more tubular / tower-shaped sections that are adjacent to each other and arranged in a stepped manner. The closer a single tubular / tower-shaped section is to the optical fiber, the more radiation is guided or channeled through that component. Each optical fiber may correspond to only one tubular / tower-shaped section, but two or more tubular / tower-shaped sections may also be used per optical fiber to guide more radiation.

[0019] In some embodiments, the guide holes on the dispenser are one of the injection holes. This avoids the need for additional holes in the minimum configuration of a system used for wet chemical treatment of a substrate surface.

[0020] In some embodiments, the guide hole on the dispenser is a drain hole for discharging wet chemicals from the substrate surface. A drain hole is another option if an existing drain hole for purposes such as drainage already exists, eliminating the need for an additional hole. The drain hole may extend through the cross-section of the dispenser, connecting its opposing surfaces as a through-hole. This cross-section can be understood as being parallel to the main surface of the dispenser. More information regarding drain holes is provided below.

[0021] In some embodiments, the guide orifice on the dispenser is a separate orifice. A separate orifice means it is neither a jet orifice nor a drain orifice. This embodiment allows the guide orifice to be precisely designed to guide the first and / or second radiation without considering other uses, such as flow control or drainage. The diameter of the separate orifice can be larger than that of the jet orifice, preferably at least 1.5 times the diameter, more preferably at least twice the diameter. The diameter of the separate orifice can also be larger than that of the drain orifice, preferably at least 1.5 times the diameter, more preferably at least twice the diameter.

[0022] Of course, in each of the above cases, multiple guide holes may exist, which can be of the same type or a mixture of multiple types. This means that guide holes such as injection holes, discharge holes, and / or independent holes can coexist. Guide holes can be used in conjunction with transparent or translucent (entire, partial, or tubular / tower-shaped) dispensing bodies.

[0023] The system disclosed herein for wet chemical treatment of a substrate can be applied to both non-electrochemical and electrochemical wet chemical treatments. In some embodiments, the system for wet chemical treatment of a substrate is also a system for electrochemical treatment of a substrate surface. The electrochemical treatment may be etching. The wet chemical treatment agent may be an etchant. The distribution body may include drainage holes. These drainage holes can be used to distribute potential relative to the substrate surface. Electrochemical wet chemical treatment is more efficient than non-electrochemical wet chemical treatment. Drainage holes can further improve the efficiency and / or uniformity of wet chemical treatment, especially etching.

[0024] As described above, the effluent orifice can also be configured to drain wet chemicals from the substrate surface. The structure of the effluent orifice allows for unidirectional diffusion of the etchant from the substrate surface. Therefore, the effluent orifice can further improve the efficiency and / or uniformity of wet chemical processing (especially etching). The effluent orifice can penetrate the cross-section of the dispenser, connecting its opposing surfaces in the form of a through-hole. This cross-section can be understood as being parallel to the main surface of the dispenser. Furthermore, at least one effluent orifice can be a guide hole.

[0025] A distribution system consisting of injection and discharge orifices can be called a high-speed processing (HSP) distribution system. This system can guide (and return) wet chemicals to the substrate surface to be treated in a high-speed and controlled manner. The HSP system can also distribute wet chemicals and potential on the substrate surface in a controlled and optimized manner.

[0026] In some embodiments, the waveguide module includes a first optical fiber leading from a radiation source to a distribution body. If the radiation source is located inside or in contact with the distribution body, the first optical fiber may be omitted. The waveguide module may also include a separate second optical fiber leading from the distribution body to a sensor element. The first optical fiber can guide first radiation from the radiation source to a substrate surface. The second optical fiber can guide second radiation from the substrate surface to the sensor element. The first and second optical fibers are not the same element. On the substrate surface, wet chemical treatment may alter the surface composition and / or layer thickness of the substrate surface, thereby affecting the reflection of the first radiation. This process-related reflected first radiation (i.e., the second radiation) can be guided to the sensor element via the second optical fiber. The sensor element can detect and / or analyze specific information such as material properties and / or thickness contained in the second radiation. This allows for in-situ, real-time analysis of process conditions. The sensor element (e.g., a signal receiver located outside a process chamber) can receive the second radiation via the second optical fiber.

[0027] In some embodiments, the waveguide module includes a combined optical fiber extending from a radiation source to a distributor and then to a sensor element. This combined optical fiber consists of only one fiber, combining the functions of a first fiber and a second fiber. This can be advantageous in space-constrained environments. The sensor element may be part of the radiation source. The radiation source and sensor element may be configured to receive pulsed signals. A splitter element, such as a prism, may be provided. The radiation source and sensor element may be located outside the wet chemical processing chamber housing the distributor.

[0028] The first optical fiber, the second optical fiber, and / or the combined optical fiber may pass through a transparent or semi-transparent (entire, partial, or tubular / tower-like) distribution body and / or through a guide hole (in the form of a jet hole, a discharge hole, or a separate hole).

[0029] In some embodiments, the first optical fiber, the second optical fiber, and / or the combined optical fiber are acid-resistant optical fibers. The first optical fiber, the second optical fiber, and / or the combined optical fiber may comprise glass and / or plastic, preferably polymeric materials, and more preferably polymethyl methacrylate (PMMA). Plastic optical fibers are advantageous for narrow (space-constrained) integration scenarios because they allow for smaller bending radii. The bending radius can be further reduced by heating the optical fiber. The first optical fiber, the second optical fiber, and / or the combined optical fiber may be equipped with a collimating lens. The diameter of the first optical fiber, the second optical fiber, and / or the combined optical fiber ranges from 1.5 to 0.1 mm, preferably 1 to 0.3 mm, and more preferably 0.7 to 0.5 mm. If the optical fiber passes through an outlet aperture, the optical fiber diameter should be equal to or smaller than the outlet aperture diameter (e.g., an optical fiber with a diameter of 0.6 mm requires an outlet aperture with a diameter of at least 0.6 mm). If the diameter of the optical fiber is the same as the diameter of the outlet aperture, then it is obvious that in this case, the outlet aperture does not function as an outlet aperture but is purely for embedding optical fibers (e.g., the second optical fiber).

[0030] Of course, multiple, several, or multiple sets of "first optical fibers," "second optical fibers," and / or "combined optical fibers" can be used to perform measurements at multiple, several, or multiple sets of measurement points to improve measurement accuracy and / or surface treatment quality and / or uniformity.

[0031] In some embodiments, the radiation source is integrated into the dispensing body. Thus, there may be no distance between the radiation source and the wet chemicals. The first optical fiber may be omitted. In some embodiments, the radiation source is separate from and independent of the dispensing body. The radiation source may be located inside or outside the wet chemical processing chamber housing the dispensing body. A radiation source located inside the wet chemical processing chamber may be integrated into the dispensing body or located near or "behind" the dispensing body. "Behind" refers to the location behind the area where the substrate is placed during processing. A radiation source located outside the wet chemical processing chamber may use a combination of optical fibers extending from the radiation source to the dispensing body and from the dispensing body to a sensor element. The sensor element may be part of the radiation source. This may be advantageous in extremely space-constrained environments. The radiation source and sensor element may be configured to receive pulsed signals.

[0032] In some embodiments, the radiation transmission surface of the dispenser is polished, preferably to a roughness in the range of 3µm–0.02µm Ra, more preferably in the range of 2µm–0.1µm Ra. Polishing the surface can further enhance the optical properties of the transmission surface and the performance of the dispenser (these portions).

[0033] In some embodiments, the radiation source is configured to provide a first radiation having an electromagnetic spectrum with a peak at 458 nm (±10 nm) or 540 nm (±10 nm). In some embodiments, the sensor element is configured to detect a second radiation having an electromagnetic spectrum in the range of 200 to 1100 nm, preferably 400 to 800 nm, more preferably 500 to 700 nm.

[0034] In some embodiments, the system for wet chemical treatment of a substrate surface further includes a substrate holder. The substrate holder is configured to hold the substrate parallel to the main surface of the dispenser. The main surface is understood as the surface facing the substrate during treatment. The substrate holder and the substrate can be arranged horizontally, where "horizontal" means relative to the ground. This arrangement is suitable for, for example, very large panels (e.g., 1 meter x 1 meter). Alternatively, the substrate holder is arranged vertically to hold the substrate vertically next to a vertically arranged dispenser. "Vertical" means relative to the ground. The dispenser and waveguide module can be inserted for wet chemical treatment through openings in the chamber wall or the top of the chamber. The substrate holder can be configured to hold only one side of the substrate. The substrate holder can also be configured to hold the front of one substrate and the back of another substrate (double-sided substrate holder).

[0035] A substrate holder can be configured to hold a substrate. The substrate holder can be a separate component for holding the substrate, or it can be part of an anode (e.g., during material removal processes such as etching) to place the substrate directly onto the anode. The substrate holder can have any size and shape to hold any type of substrate. In addition to stably holding the substrate, the substrate holder can also function as an anode by directly providing a potential to the substrate. By applying a potential, electrons can be extracted from the conductive material on the substrate surface. The substrate holder can be electrically connected to the positive terminal of a DC power supply (e.g., during material removal processes such as etching; or to the negative terminal if material deposition is performed). The substrate holder can include multiple electrical contacts for holding the substrate. A cathode can be electrically connected to the negative terminal of a DC power supply (e.g., during material removal processes such as etching; or to the positive terminal if material deposition is performed). The cathode can be located on one side of the distribution body, opposite the side facing the substrate during processing.

[0036] In some embodiments, the substrate holder is stationary and configured to hold the substrate in place without rotation during wet chemical treatment. This does not preclude the use of rotary agitation (slight back-and-forth motion) to improve the chemical treatment effect on the substrate surface. However, this excludes the complete rotation and / or repeated rotation of the substrate holder and substrate as described in prior art for horizontal chemical spin coating systems—that is, the method of adjusting the wet chemical layer by controlling the spin coating speed.

[0037] Systems for wet chemical treatment of substrate surfaces may also include reservoirs or baths for holding the wet chemicals. These wet chemicals may be specifically optimized for the material being treated. The bath may be configured to allow complete immersion of the substrate.

[0038] According to this disclosure, a method for wet chemical treatment of a substrate surface is also proposed. This method for wet chemical treatment of a substrate surface includes (but not necessarily in this order): Wet chemicals are dispensed relative to the substrate surface using spray holes provided in the dispensing body. The first electromagnetic radiation is provided by a radiation source. The first radiation from the radiation source is guided through the distribution body using a waveguide module. The waveguide module guides the second radiation through the distribution body and to the sensor element, wherein the second radiation is the reflected radiation of the first radiation at the substrate surface, and The second radiation is detected using the sensor element.

[0039] This disclosure provides an improved method for wet chemical treatment of a substrate surface, which enables simpler control of the wet chemical treatment. A second radiation source serves as the basis for controlling the wet chemical treatment of the substrate surface. Surprisingly, this can be achieved simply by using existing dispensing agents to guide the first and second radiation sources. Compared to prior art, the method for wet chemical treatment of a substrate surface described in this disclosure requires neither a horizontal chemical spin-coating system nor relies on complex physical assumptions and mathematical models.

[0040] In some embodiments, wet chemical treatment is an etching process. The method may further include: Analyze the surface property data of the substrate surface provided by at least the second radiation to determine the end of the etching process.

[0041] The method for wet chemical treatment of a substrate can also be used as a method for electrochemical treatment of a substrate surface. The wet chemical can be an etchant. The distribution body can include an effluent orifice. The effluent orifice can be configured to distribute a potential relative to the substrate surface. Thus, the effluent orifice can further improve the etching effect. As mentioned above, the effluent orifice can also be configured to discharge the wet chemical from the substrate surface. The effluent orifice can have a structure to provide a unidirectional distribution of the etchant from the substrate surface outwards. Thus, the effluent orifice can further improve the efficiency and / or uniformity of the wet chemical treatment (especially etching). The cross-sectional area of ​​the effluent orifice is at least twice the cross-sectional area of ​​the jet orifice. For example, if the cross-sectional area of ​​the jet orifice is 0.1 mm², then the cross-sectional area of ​​the effluent orifice is at least 0.2 mm².

[0042] The processing unit (e.g., a computer) can determine or calculate the end time of a wet chemical treatment (e.g., an etching process) based on analyzed substrate surface property data (e.g., material properties and / or thickness-related information). The analysis or acquisition of surface property data is based at least on a second radiation, and optionally on a comparison of the second radiation with a first radiation. Empirical factors can be added to the calculated wet chemical treatment end time to obtain the actual completion time of the wet chemical treatment. The second radiation data used to acquire the surface property data can be the change in reflected signal intensity over time. Not only direct signal intensity can be used, but also attenuated signals and / or derivative signals (e.g., first derivative, second derivative). The end time of the wet chemical treatment can be defined as when the intensity exceeds a specific threshold or reaches a specific slope. Endpoint detection can be based on reflectance or elliptic polarization spectroscopy. The end time of the wet chemical treatment can be output in the form of "duration since start," for example, 49.5 seconds.

[0043] It should be understood that the systems and methods described in the independent claims have similar and / or identical preferred embodiments, particularly the preferred embodiments defined in the dependent claims. Furthermore, it should be understood that the preferred embodiments of this disclosure can also be any combination of dependent claims and corresponding independent claims.

[0044] These and other aspects of this disclosure will become apparent from and be illustrated in the embodiments described below. Attached Figure Description

[0045] Exemplary embodiments of this disclosure will now be described with reference to the following figures: Figure 1a and 1b An embodiment of a system for wet chemical treatment of a substrate surface according to the present disclosure is illustrated schematically and exemplary.

[0046] Figure 2 An embodiment of a system for wet chemical treatment of a substrate surface according to the present disclosure is illustrated schematically and exemplary.

[0047] Figure 3 An embodiment of a system for wet chemical treatment of a substrate surface according to the present disclosure is illustrated schematically and exemplary.

[0048] Figure 4 An embodiment of a system for wet chemical treatment of a substrate surface according to the present disclosure is illustrated schematically and exemplary.

[0049] Figure 5a and 5bDetails of an embodiment of a system for wet chemical treatment of a substrate surface according to the present disclosure are illustrated schematically and exemplary.

[0050] Figure 6 Details of an embodiment of a system for wet chemical treatment of a substrate surface according to the present disclosure are illustrated schematically and exemplary.

[0051] Figure 7 An embodiment of a method for wet chemical treatment of a substrate surface according to the present disclosure is illustrated schematically and exemplary. Detailed Implementation

[0052] Figure 1a and Figure 1b An embodiment of a system 10 for wet chemical treatment of a substrate surface 41 according to the present disclosure is illustrated schematically and exemplary. Here, the wet chemical treatment is material removal, such as etching. The substrate 4 may be a wafer or a panel. The substrate surface 41 may be a wafer surface. A substrate holder 42 holds the substrate 4.

[0053] The system 10 for wet chemical treatment of substrate surface 41 includes a radiation source 11 for providing first electromagnetic radiation 12. The radiation source 11 can be an LED or a halogen lamp. The provided first electromagnetic radiation 12 can be light, particularly a light beam. The first electromagnetic radiation 12 can have a single electromagnetic wavelength, multiple electromagnetic wavelengths, or can include an electromagnetic wavelength spectrum.

[0054] System 10 also includes an HSP dispenser 13 having a spray orifice 14. The spray orifice 14 is configured to dispense wet chemical 30 relative to the substrate surface 41. The spray orifice 14 has a shape for increasing the velocity of the wet chemical 30. The spray orifice 14 extends at least partially through a cross-section of the dispenser 13. The cross-section can be understood as parallel to the main surface of the dispenser 13. The main surface can be understood as the surface facing the substrate 4 when processing the substrate 4.

[0055] Injection hole 14 (see) Figure 1bThe internal space 25 of the dispensing body 13 is connected to a surface of the dispensing body 13 that faces the substrate 4 during processing. The internal space 25 of the dispensing body 13 is pressurized, causing wet chemicals 30 to be sprayed toward the substrate surface 41. For example, the wet chemicals 30 are supplied laterally from the edge of the dispensing body 13 into the internal space 25, such as from above, below, or to the side. The spray holes 14 may simply connect, for example, a “spray head plate” of the dispensing body 13 to the space 26 located between the dispensing body 13 and the substrate 4 during processing. The spray head plate can be understood as a plate including a plurality of spray holes 14 configured to face the substrate 4 during processing. Here, the spray holes 14 supply the wet chemicals 30 from the liquid inlet of the dispensing body 13. The spray holes 14 open to the internal space 25 and face the substrate 4 during processing. The axis of the spray holes 14 is substantially perpendicular to the first side.

[0056] System 10 also includes a sensor element 16 for detecting the second radiation 17. The sensor element 16 can be understood as a signal receiver and can be a spectrometer. The second radiation 17 is the reflected radiation of the first radiation 12 at the substrate surface 41. The second electromagnetic radiation can be light, especially a light beam. The second electromagnetic radiation can have a single electromagnetic wavelength, multiple electromagnetic wavelengths, or can include an electromagnetic wavelength spectrum. The radiation source 11 and the sensor element 16 are jointly housed in the source-receiver module 24.

[0057] System 10 also includes at least one waveguide module 15. Waveguide module 15 includes at least a portion of distribution body 13. Waveguide module 15 is configured to guide first radiation 12 from radiation source 11 through distribution body 13. Waveguide module 15 is also configured to guide second radiation 17 through distribution body 13 and to sensor element 16.

[0058] The first radiation 12 and the second radiation 17 are guided through the transparent portion 18 of the distributor 13. Only these transparent portions 18 of the distributor 13 may be made of a transparent plastic material, or most or all of the distributor 13 may be made of a transparent plastic material. The transparent plastic material may be a transparent polymer material, preferably transparent PMMA. The transparent portion, most of the transparent portion, or the entire transparent portion of the distributor 13 may be considered part of the waveguide module 15. The radiation transmission surface 23 of the distributor 13 may be polished to a roughness in the range of 3µm to 0.02µm Ra.

[0059] The transparent portion 18 in the distributor 13 for guiding the first radiation 12 and / or the second radiation 17 is, here, a tower-shaped or tubular portion 19 of the distributor 13. The tubular portion 19 of the distributor 13 forms a connecting channel to guide: 1) the first radiation 12 from the radiation source 11 through the distributor 13 and to the substrate surface 41; and 2) the second radiation 17 from the substrate surface 41 through the distributor 13 and to the sensor element 16.

[0060] The first radiation 12 and the second radiation 17 are guided not only by corresponding portions of the distributor 13, but also through guide holes 20 in the distributor 13. The guide holes 20 can be considered part of the waveguide module 15. This disclosure provides a first guide hole 20 for the first radiation 12 and a second guide hole 20 for the second radiation 17. This disclosure may also provide multiple guide holes 20 to increase the amount of radiation transmitted.

[0061] The guide hole 20 in the dispenser 13 can be a spray hole 14 and / or a discharge hole 21. The discharge hole 21 is configured to discharge wet chemical 30 from the substrate surface 41. The discharge hole 21 extends through a cross-section of the dispenser 13 and connects to the opposite surface of the dispenser 13 in the form of a through hole. The cross-section can still be understood as parallel to the main surface of the dispenser 13. The discharge hole 21 can also be configured to distribute a potential relative to the substrate surface 41. The discharge hole 21 is formed by a tube extending from one surface of the dispenser 13 to the opposite side of the dispenser 13. This tube separates the interior of the discharge hole from the interior space 25 of the dispenser 13 that supplies wet chemical to the spray hole 14.

[0062] The guide hole 20 in the dispenser 13 can also be a separate hole 22. A separate hole 22 means that it is neither a spray hole 14 nor a discharge hole 21. Of course, guide holes 20 in the form of spray holes 14, discharge holes 21 and / or separate holes 22 can coexist. Guide holes 20 can be used in combination with the transparent dispenser 13 (a part of the dispenser 13 or the tubular portion 19).

[0063] Waveguide module 15 includes a first optical fiber 32 extending from radiation source 11 to distribution body 13. Waveguide module 15 also includes a separate second optical fiber 37 extending from distribution body 13 to sensor element 16. The first optical fiber 32 and the second optical fiber 37 are guided through the transparent portion 18 and tubular portion 19 of distribution body 13 and guide holes 20 (e.g., in the form of injection holes 14, discharge holes 21, or separate holes 22). The first optical fiber 32 guides first radiation 12 from radiation source 11 to substrate surface 41. The second optical fiber 37 guides second radiation 17 from substrate surface 41 to sensor element 16. At substrate surface 41, wet chemicals 30 alter the surface composition and / or layer thickness of substrate surface 41, thereby affecting the reflected radiation of the first radiation 12. This process-related reflected first radiation 12 (i.e., second radiation 17) is guided to sensor element 16 via second optical fiber 37. Sensor element 16 detects and / or analyzes, for example, material properties and / or thickness-related information contained in the second radiation 17. This enables in-situ and real-time interpretation of the processing status. Sensor element 16 (e.g., signal receiver) receives second radiation 17 via second optical fiber 37.

[0064] Here, the wet chemical treatment is an electrochemical treatment of the substrate surface 41, and is an etching process. The wet chemical 30 is an etchant. The sensor element 16 is configured to analyze surface property data of the substrate surface 41 provided by at least the second radiation 17 to determine the end of the etching process. The wet chemical 30 alters the surface composition and / or layer thickness at the substrate surface 41, thereby affecting the reflected radiation of the first radiation 12, which is the second radiation 17. This process-related reflected radiation is guided to the sensor element 16 via a waveguide module 15, and the sensor element 16 detects and analyzes the surface property data (e.g., material properties and / or thickness-related information) contained in the second radiation 17. Thus, a highly accurate endpoint detection system 10 for etching processes can be realized, by which only a precisely defined amount of material can be removed.

[0065] The substrate 4 is held in a substrate holder 42, which provides an anode function by directly applying a potential to the substrate 4. By applying the potential, electrons can be extracted from the conductive material at the surface 41 of the substrate 4. The substrate holder 42 can be electrically connected to the positive terminal of a DC power supply (in the case of material removal, such as etching; if material deposition is performed, it is connected to the negative terminal). The substrate holder 42 may include a plurality of electrical contacts for the substrate 4. The cathode can be electrically connected to the negative terminal of the DC power supply (in the case of material removal, such as etching; if material deposition is performed, it is connected to the positive terminal).

[0066] The substrate holder 42 is vertically arranged to hold the substrate 4 vertically next to the equally vertically arranged distributor 13. The distributor 13 and the waveguide module 15 can be inserted through an opening in the cavity wall or from an opening in the top of the cavity for wet chemical processing.

[0067] Figure 2 An embodiment of a system for wet chemical treatment of a substrate surface 41 according to the present disclosure is illustrated schematically and exemplary. The system includes a radiation source 11 for providing first electromagnetic radiation 12 (see FIG. 1). The radiation source 11 is disposed within a wet chemical treatment chamber housing a transparent dispensing body 13. Specifically, the radiation source 11 is integrated into the dispensing body 13. The radiation source 11 allows radiation to pass through the transparent dispensing body 13 and reach the substrate surface 41. There is substantially no distance between the radiation source 11 and the wet chemicals 30.

[0068] The system for wet chemical treatment of substrate surface 41 also includes a sensor element 16 for detecting second radiation 17. The sensor element 16 is spaced apart from the dispensing body 13 but still located within the wet chemical treatment chamber. The sensor element 16 can be connected to a processing unit configured to calculate the endpoint of the wet chemical treatment based on the detected surface property data. The system also includes power supplies 33, 38 spaced apart from the dispensing body 13, for example located outside the wet chemical treatment chamber, configured to supply power to the radiation source 11 and / or the sensor element 16.

[0069] The system for wet chemical treatment of substrate surface 41 also includes a waveguide module 15 having a transparent distribution body 13. The waveguide module 15 is configured to guide a first radiation 12 (not shown) from radiation source 11 through the distribution body 13 and a second radiation 17 (not shown) through the distribution body 13 to the sensor element 16. The second radiation 17 is the reflected radiation of the first radiation 12 at substrate surface 41. The waveguide module 15 includes a guide hole 20 in the distribution body 13. Here, the guide hole 20 in the distribution body 13 is a separate hole 22. A separate hole 22 means that it is neither a jet hole nor a discharge hole. The diameter of the separate hole 22 is larger than the diameter of either a jet hole or a discharge hole.

[0070] Since the radiation source 11 is embedded in or attached to the guide hole 20 in the distribution body 13, there is no need to provide a first optical fiber 32 to guide the first radiation 12 from the radiation source 11 through the distribution body 13. However, the waveguide module 15 includes a second optical fiber 37 extending from the distribution body 13 to the sensor element 16 to guide the second radiation 17 from the substrate surface 41 to the sensor element 16.

[0071] Figure 3An embodiment of a system for wet chemical treatment of a substrate surface 41 according to the present disclosure is illustrated schematically and exemplary. The system also includes a radiation source 11 for providing first electromagnetic radiation 12 (not shown). Here, the radiation source 11 is separate from and independent of the dispensing body 13. The radiation source 11 is still disposed within the wet chemical treatment chamber housing the dispensing body 13, such that the radiation source 11 is positioned adjacent to or "behind" the dispensing body 13. Therefore, the radiation source 11 can allow radiation to pass through the dispensing body 13 and reach the substrate surface 41. The dispensing body 13 includes an injection port 14 and an exhaust port 21.

[0072] The system for wet chemical treatment of substrate surface 41 also includes a sensor element 16 for detecting the second radiation 17. Sensor element 16 is also spaced apart from the dispensing body 13, but still located within the wet chemical treatment chamber. Sensor element 16 may also be connected to a processing unit configured to calculate the endpoint of the wet chemical treatment based on the detected surface property data. The system also includes a first power supply 33 configured to power radiation source 11 and a second power supply 38 configured to power sensor element 16.

[0073] The system for wet chemical treatment of the substrate surface 41 also includes a waveguide module 15, which includes a first optical fiber 32 and a second optical fiber 37. The first optical fiber 32 guides first radiation 12 from the radiation source 11 through the discharge hole 21 in the distributor 13, and the second optical fiber 37 guides second radiation 17 through the injection hole 14 in the distributor 13 and to the sensor element 16. The second radiation 17 is the reflected radiation of the first radiation 12 at the substrate surface 41.

[0074] Figure 4 An embodiment of a system for wet chemical treatment of a substrate surface 41 according to the present disclosure is illustrated schematically and exemplary. The system also includes a radiation source 11 for providing first electromagnetic radiation 12. Here, the radiation source 11 is separate from and independent of the dispensing body 13. The radiation source 11 is disposed outside the wet chemical treatment chamber housing the dispensing body 13. The radiation source 11 may be combined with a sensor element 16, which is also separate from and independent of the dispensing body 13 and is also disposed outside the wet chemical treatment chamber. The radiation source 11 and the sensor element 16 may share power supplies 33, 38.

[0075] Here, waveguide module 15 includes a combined optical fiber 35 that extends from radiation source 11, through jet orifice 14 in distributor 13, and from distributor 13 to sensor element 16. No other optical fibers are present. Radiation source 11 and sensor element 16 can be configured for pulsed signals. Beam-splitting elements such as semi-transparent mirrors or prisms can be placed in the radiation path to transmit the returned second radiation to sensor element 16.

[0076] The system for wet chemical treatment of the substrate surface also includes a bath 36 for containing the wet chemicals 30. The bath 36 is sized to completely immerse the substrate 4 in the wet chemicals 30. The substrate 4 is positioned between two dispensing bodies 13, which are two dispensing plates for the HSP. The substrate 4 is held by a substrate holder. Figure 4 In the diagram, the base retainer is shown at the upper and lower ends of the base 4.

[0077] Figure 5a and Figure 5b Details of an embodiment of a system for wet chemical treatment of a substrate surface according to the present disclosure are illustrated schematically and exemplary. The system is shown in a cross-sectional perspective view. Figure 5a A detailed view shows a portion of the chamber wall of the wet chemical processing chamber 31 and a portion of the distribution body 13 having injection holes 14 and discharge holes 21. The arrangement of the injection holes 14 and discharge holes 21 shown on the right corresponds to the spray head plate of the so-called distribution body 13. A first optical fiber 32, located in the optical fiber housing 34, enters the wet chemical processing chamber 31. Figure 5b As shown, multiple radiation sources 11 are arranged around the first optical fiber 32 and close to the free end of the optical fiber housing 34. The first optical fiber 32 exits the optical fiber housing 34 through the window 39. The first optical fiber 32 extends to the distribution body 13 and enters the guide hole 20.

[0078] The first radiation 12 (and the second radiation 17, not shown) is guided through the transparent tubular / tower-like portion 19 of the distributor 13. The tubular portion 19 of the distributor 13 forms a connecting channel to guide the first radiation 12 from the radiation source 11 through the distributor 13 (and to the substrate surface 41). The tubular portions 19 are arranged side by side, adjacent to each other, and parallel to each other. The closer a single tubular / tower-like portion 19 is to the optical fiber 32, the more radiation is guided or channeled through the corresponding tubular / tower-like portion 19. Each optical fiber 32 may correspond to only one tubular / tower-like portion 19, or two or more tubular / tower-like portions 19 may be used per optical fiber 32 to guide more radiation to the substrate surface 41. In the example shown, when multiple tubular or tower-like portions 19 are used, the light intensity is highest in the tubular or tower-like portions 19 distributed around the optical path and gradually decreases in each tubular or tower-like portion 19 as the distance from the optical path increases.

[0079] Figure 6 Details of an embodiment of a system for wet chemical treatment of a substrate surface 41 according to the present disclosure are illustrated schematically and exemplary. Figure 6 A transparent dispenser 13 is shown, which allows radiation from a radiation source 11 (not shown) to pass through the dispenser 13 and reach a substrate surface 41 (also not shown). In particular, the radiation is transmitted (at least partially) through a wet chemical 30 within the internal space 25 of the dispenser 13.

[0080] Figure 7 An embodiment of a method for wet chemical treatment of a substrate surface 41 according to the present disclosure is illustrated schematically and exemplary. The method includes the following steps: In step S1, wet chemical 30 is dispensed relative to the substrate surface 41 using the spray hole 14 provided in the dispensing body 13.

[0081] In step S2, the first electromagnetic radiation 12 is provided by the radiation source 11.

[0082] In step S3, the waveguide module 15 guides the first radiation 12 from the radiation source 11 through the distributor 13.

[0083] In step S4, the waveguide module 15 guides the second radiation 17 through the distribution body 13 and to the sensor element 16, wherein the second radiation 17 is the reflected radiation of the first radiation 12 at the substrate surface 41.

[0084] In step S5, the second radiation 17 is detected using sensor element 16.

[0085] Optionally, it also includes: In step S6, surface property data of the substrate surface 41 provided by at least the second radiation 17 are analyzed to determine the end of the etching process.

[0086] The method used for wet chemical treatment can also be used as a method for electrochemical treatment of the substrate surface 41. In this case, the wet chemical 30 is an etchant. The dispensing body 13 includes a discharge hole 21 for distributing a potential relative to the substrate surface 41 and discharging the wet chemical 30 from the substrate surface 41.

[0087] The processing unit (e.g., a computer) calculates the endpoint of the etching process based on surface property data (e.g., material properties and / or thickness-related information) of the analyzed substrate surface 41. The surface property data is analyzed or obtained based on at least the second radiation 17, and optionally also based on a comparison between the second radiation 17 and the first radiation 12.

[0088] It should be noted that the various embodiments of this disclosure are described with reference to different subject matter. In particular, some embodiments are described with reference to claims of the method type, while others are described with reference to claims of the apparatus type. However, those skilled in the art will understand from the above and following description that, unless otherwise stated, this disclosure discloses not only any combination of features belonging to the same subject matter type, but also any combination of features involving different subject matter types. Furthermore, all features can be combined to produce synergistic effects beyond the simple superposition of the features.

[0089] Although this disclosure has been shown and described in detail in the accompanying drawings and the foregoing description, these illustrations and descriptions should be considered illustrative or exemplary, and not restrictive. This disclosure is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and implemented by those skilled in the art when implementing the claimed disclosure, through study of the drawings, this disclosure, and the dependent claims.

[0090] In the claims, the word "comprising" does not exclude other elements or steps, and "an" does not exclude multiple. A single processor or other unit can perform the functions of multiple items described in the claims. The fact that certain measures are described separately in different dependent claims does not in itself imply that combinations of these measures cannot be advantageously used. No reference numerals in the claims should be construed as limiting the scope of protection.

Claims

1. A system (10) for wet chemical treatment of a substrate surface (41), comprising: - The radiation source (11) is configured to provide first electromagnetic radiation (12). - Dispenser (13), comprising at least a spray hole (14), wherein the spray hole (14) is configured to dispense wet chemicals (30) relative to the substrate surface (41). - At least one waveguide module (15), wherein the waveguide module (15) is configured to guide a first radiation (12) from the radiation source (11) through the distributor (13), and - Sensor element (16) is configured to detect a second radiation (17), which is the reflected radiation of the first radiation (12) at the substrate surface (41). -The waveguide module (15) is also configured to guide the second radiation (17) through the distributor (13) and to the sensor element (16).

2. The system (10) according to claim 1, wherein, The wet chemical treatment is an etching process, and the sensor element (16) is also configured to analyze surface property data of the substrate surface (41) provided by at least the second radiation (17) to determine the end of the etching process.

3. The system (10) according to any one of the preceding claims, wherein, The first radiation (12) and / or the second radiation (17) are guided through the transparent portion (18) of the dispenser (13) or the guide hole (20) in the dispenser (13).

4. The system (10) according to the preceding claim, wherein, The guide hole (20) in the dispenser (13) is one of the spray hole (14), the discharge hole (21) configured to discharge the wet chemical (30) from the substrate surface (41), or a separate hole (22).

5. The system (10) according to any one of the preceding claims, wherein, The system (10) for wet chemical treatment of the substrate (4) is also a system for electrochemical treatment of the substrate surface (41), and the dispensing body (13) includes a discharge orifice (21) which is also configured to distribute a potential relative to the substrate surface (41).

6. The system (10) according to any one of the preceding claims, wherein, The dispenser (13) is made of a material configured to transmit electromagnetic spectra in the range of 100 nm to 2000 nm, preferably a transparent plastic material, more preferably a transparent polymer material, and even more preferably a transparent PMMA (polymethyl methacrylate) material.

7. The system (10) according to any one of the preceding claims, wherein, When viewed in cross-section, the waveguide module (15) includes a tubular portion (19) of the distribution body (13), wherein the tubular portion (19) of the distribution body (13) is made of a transparent plastic material.

8. The system (10) according to any one of the preceding claims, wherein the waveguide module (15) includes a first optical fiber (32) extending from the radiation source (11) to the distributor (13), and / or a separate second optical fiber (37) extending from the distributor (13) to the sensor element (16).

9. The system (10) according to any one of claims 1-7, wherein, The waveguide module (15) includes a combined optical fiber (35) extending from the radiation source (11) to the distributor (13) and from the distributor (13) to the sensor element (16), wherein the sensor element (16) is part of the radiation source (11), and the radiation source (11) and the sensor element (16) are configured for pulse signals.

10. The system (10) according to any one of the preceding two claims, wherein, The optical fibers (32, 37) are acid-resistant glass optical fibers or acid-resistant plastic optical fibers, and preferably have collimating lenses.

11. The system (10) according to any one of the preceding claims, wherein, The radiation source (11) is integrated into the distribution body (13), or is separate from and independent of the distribution body (13), and is located inside or outside the wet chemical processing chamber (31) that houses the distribution body (13).

12. The system (10) according to any one of the preceding claims, wherein, The radiation transmission surface (23) of the distributor (13) is polished to a roughness in the range of 3µm to 0.02µm Ra.

13. The system (10) according to any one of the preceding claims, wherein, The radiation source (11) is configured to provide the first radiation (12) with a peak at 458 nm or 540 nm.

14. The system (10) according to any one of the preceding claims further includes a vertically arranged base holder (42) configured to vertically hold the base (4) next to a vertically arranged distribution body (13).

15. A method for wet chemical treatment of a substrate surface (41), comprising: - Wet chemicals (30) are dispensed relative to the substrate surface (41) using spray holes (14) provided in the dispensing body (13). - The first electromagnetic radiation (12) is provided by the radiation source (11). - The first radiation (12) from the radiation source (11) is guided through the distributor (13) using the waveguide module (15). - The waveguide module (15) guides the second radiation (17) through the distribution body (13) and to the sensor element (16), wherein the second radiation (17) is the reflected radiation of the first radiation (12) at the substrate surface (41), and - The second radiation (17) is detected using the sensor element (16).

16. The method according to the preceding claim, wherein, The wet chemical treatment is an etching process, and the method further includes: Analyze the surface property data of the substrate surface (41) provided by at least the second radiation (17) to determine the end of the etching process.

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