Beamlines, laser systems and TLE systems for laser beams

Abstract

The present invention relates to a beamline (10) for a laser beam (220) of a thermal laser evaporation (TLE) system (300), the beamline (10) extending between a source end (20) of the beamline (10) and a chamber end (30) of the beamline (10), such that the source end (20) is connectable to a laser light source (210) and the chamber end (30) is connectable to a reaction chamber (310) of the TLE system (300), the beamline (10) including one or more laser beam sources (210) for modifying and / or controlling the characteristics of the laser beam (220). and / or one or more linear guiding sections (52), each of the optical section (50) and the guiding section (52) having an upstream end (60) with a first connection interface (64), a downstream end (66) with a second connection interface (70), and a section cavity (56) extending continuously within the housing (54) from the first section opening (62) at the upstream end (60) to a second section opening (68) at the downstream end (66). The present invention further relates to a laser system (200) for a TLE system (300), the laser system (200) comprising a laser source (210) for providing a laser beam (220), and the beamline (10). The present invention further relates to a TLE system (300) comprising a reaction chamber (310) that can be filled with a reaction atmosphere (312), a substrate (316) disposed in the reaction chamber (310), one or more sources (314) disposed in the reaction chamber (310), and a laser system (200) for providing a laser beam (220) for evaporating and / or sublimating material from the sources (314) and / or for heating material from the substrate (316).

Description

[Technical Field]

[0001] The present invention relates to a beamline for a laser beam of a thermal laser evaporation (TLE) system, the beamline extending between a source end of the beamline and a chamber end of the beamline, the source end being connectable to a laser light source and the chamber end being connectable to a reaction chamber of the TLE system; The above beamline is one or more optical sections for modifying and / or controlling the properties of said laser beam; and / or - one or more linear guidance sections Equipped with The optical section and the guidance section each have a housing with an upstream end having a first connection interface, a downstream end having a second connection interface, and a section cavity extending continuously within the housing from the first section opening at the upstream end to the second section opening at the downstream end.The present invention also relates to a laser system for a TLE system, the laser system comprising a laser source for providing a laser beam and a beamline according to the present invention.The present invention also relates to a TLE system comprising a reaction chamber fillable with a reaction atmosphere, a substrate disposed in the reaction chamber, one or more sources disposed in the reaction chamber, and a laser system according to the present invention for providing a laser beam for evaporating and / or sublimating material from the source and / or for heating material from the substrate. [Background technology]

[0002] In TLE, a source material is evaporated and / or sublimated by laser heating in a controlled environment, in particular a reaction chamber filled with a reactive atmosphere, and is usually intended to coat a substrate also placed in the reaction chamber. Furthermore, in many applications, heating of the substrate is also advantageous, and this can also be provided by appropriately adjusting the laser light incident on the respective substrate.

[0003] In both cases, a laser beam suitable for each task must be provided. Laser beams are often generated by laser sources located outside the reaction chamber. Therefore, the laser beam from the laser source must be guided into the reaction chamber to strike the source or substrate, respectively. For short-wavelength lasers, particularly those with wavelengths around 1 μm, suitable fibers exist to conveniently guide the laser light from the source to the point of use. However, such fibers with suitably low absorption do not exist for short-wavelength (ultraviolet, UV) lasers, which are particularly useful for heating substrates, or for long-wavelength laser sources such as CO2 lasers with wavelengths of around 10 μm or less.

[0004] Additionally, for each intended use of the laser beam, either evaporation and / or sublimation of a source material or heating of a substrate, the initial properties of the laser beam provided by the laser source itself may not be ideal. These properties may include, for example, direction, size, shape, focal length, spatial intensity distribution, and / or overall intensity. Therefore, modifying and / or controlling these properties of the laser beam between the laser source and its final destination in the reaction chamber is also necessary in most applications. Summary of the Invention [Problem to be solved by the invention]

[0005] Optical setups for state-of-the-art laser beamlines, especially those for long-wavelength laser beams around 10 μm, must combine three functions: mechanical support for the optical components, a light-tight enclosure, and the possibility of flooding the beam path with an inert gas to prevent absorption of the laser beam. Typically, mechanical support is achieved by an optical table, and no enclosure is provided. Meanwhile, an enclosure must cover the entire setup on the optical table to contain the optical beam and purge gas, but it does not mechanically support the optical components. In particular, for the intended use of laser beams for TLE systems, such solutions based on an optical table are not suitable.

[0006] In view of the above, it is an object of the present invention to provide an improved beamline for a laser beam, an improved laser system, and an improved thermal laser evaporation system that do not have the above-mentioned drawbacks of the state of the art. In particular, it is an object of the present invention to provide an improved beamline for a laser beam, an improved laser system, and an improved thermal laser evaporation system that provides a simple, unified structure for directing a laser beam provided by a laser source into a reaction chamber of a TLE system, and in particular mechanically supports the means necessary to modify and / or control the properties of the laser beam, while at the same time surrounding the laser beam on its path through the beamline and preferably containing a purge gas.

[0007] The above object is achieved by the respective independent claims, in particular by a beam line for a laser beam according to independent claim 1, a laser system according to independent claim 42 and a thermal laser evaporation system according to independent claim 45. The dependent claims describe preferred embodiments of the invention. Details and advantages described with respect to the beam line according to the first aspect of the invention also refer to the laser source according to the second aspect of the invention and the thermal laser evaporation system according to the third aspect of the invention, and vice versa, wherever technically meaningful. [Means for solving the problem]

[0008] According to a first aspect of the present invention, the above object is achieved by a beamline for a laser beam of a thermal laser evaporation (TLE) system, the beamline extending between a source end of the beamline and a chamber end of the beamline, such that the source end is connectable to a laser light source and the chamber end is connectable to a reaction chamber of the TLE system; The above beamline is one or more optical sections for modifying and / or controlling the properties of said laser beam; and / or - one or more linear guidance sections Two or more of the following are present: The optical section and the guiding section each have a housing having an upstream end with a first connection interface, a downstream end with a second connection interface, and a section cavity extending continuously within the housing from the first section opening at the upstream end to the second section opening at the downstream end, and the one or more optical sections and the one or more guiding sections are arranged adjacently in pairs so that each section cavity forms a continuous beam cavity extending from the source end to the chamber end, and each section pair of the adjacently arranged optical sections and / or guiding sections is arranged by connecting the first connection interface of one section of the section pair with the second connection interface of the other section of the section pair.

[0009] The beamline according to the present invention is intended for use as part of a TLE system, which typically includes at least a reaction chamber in which a source having a material to be evaporated and / or sublimated and a substrate to be coated with the evaporated and / or sublimated source material are located. A laser source provides a laser beam used for the evaporation and / or sublimation or for heating the substrate to improve the coating process.

[0010] Reliable guidance of the laser beam from the laser source to the reaction chamber is crucial for the function of the TLE system. To achieve this, the beamline according to the present invention is configured to extend from the laser source to the reaction chamber. The source end of the beamline, which can be connected to the laser source, and the chamber end, which can be connected to the reaction chamber, ensure the connection to the laser source and the reaction chamber, respectively. Apart from the beamline according to the present invention, no other guidance means are required to guide the laser beam provided by the laser source to the reaction chamber of the TLE system.

[0011] The beamline according to the invention is composed of two or more sections, which can be provided in two different versions: an optical section and a linear guidance section, in other words, a section of the beamline according to the invention can consist of two optical sections, or two guidance sections, or any combination of one or more optical sections and one or more guidance sections.

[0012] The optical sections are each configured to modify and / or control one or more properties of the laser beam, for example to modify and / or control the average direction of the laser beam by simply reflecting it off a mirror that is tilted relative to the direction in which it is incident, or to modify and / or control the shape of the laser beam by cutting off part of it by an appropriately shaped aperture, etc. The guidance section is used as an enclosed path for the laser beam, protecting it from the environment.

[0013] Both sections share a common housing, which has a section cavity extending between a first section end at the upstream end of the housing and a second section end at the downstream end of the housing. The section cavity is used for the path of the laser beam. The size of the cross section of the section cavity perpendicular to the direction of the laser beam is therefore selected so that the laser beam can propagate through the section cavity without impinging on the inner surface of the section cavity. Thus, during operation of the TLE system, the laser beam enters the section cavity of the respective optical or guiding section through the first section opening, travels through the section cavity, and exits the respective section again through the second section opening.

[0014] The housing of each section can be made from metal, for example aluminum. For example, manufacturing the sections can include machining the housing from a monolithic block of metal. While the guidance section has a simple linear structure in which the section cavity is linear from the first section opening to the second section opening, the section cavity of the optical section can have a different shape and can, for example, consist of two linear sections connected to each other. This allows, among other things, to change and / or control the direction of the laser beam.

[0015] In the optical section, suitable means are arranged in the respective section cavities to modify and / or control the properties of the laser beam. In other words, the optical section provides the necessary mechanical support for the respective means in its section cavities. In contrast, the section cavities of the guidance section are empty and do not contain such means.

[0016] According to the present invention, the housings of the optical section and the guiding section are further configured to have a first connection interface at their respective upstream ends and a second connection interface at their respective downstream ends. These connection interfaces are configured correspondingly to each other so that each first connection interface can be connected to any second connection interface. In other words, any pair of optical section and guiding section can be attached to each other in any order, i.e., optical-optical, optical-guiding, guiding-optical, guiding-guiding.

[0017] As a result, in any pair of optical and guiding sections, the respective sections can be arranged adjacent to one another. Adjacent in the sense of the present invention means directly adjacent on both sides of the link connecting the two sections. Thus, the downstream section of a first pair of sections can also be the upstream section of the subsequent second pair of sections. Therefore, the beamline according to the present invention can consist of several sections arranged adjacent to one another. This allows any long distance between the laser source and the reaction chamber to be bridged by the beamline according to the present invention. However, if sufficient, a beamline consisting of a single pair of sections is also possible.

[0018] In particular, by combining two or more sections, whether they are optical sections, guiding sections, or both, the cavities of each section are connected to each other to form a continuous beam cavity that begins at a first opening at the upstream end of the first section of each of the combined sections and ends at a second opening at the downstream end of the last section of each of the combined sections. As a result, the beam cavity extends continuously from the source end to the chamber end of the resulting beamline. In other words, the beamline of the present invention provides an enclosure for the laser beam that begins at the source end, and thus the laser light source, and extends to the chamber end, and thus the reaction chamber. Because this beam cavity extends continuously, it can also be used to contain a purge gas.

[0019] In summary, the beamline of the present invention is a simple, unified structure for directing a laser beam from a laser source into the reaction chamber of a TLE system. It provides the optical section with mechanical support for the means necessary to modify and / or control the laser beam's properties, while simultaneously enclosing the laser beam on its path through the beamline. Additionally, it can contain a purge gas if necessary.

[0020] Furthermore, the beamline according to the present invention may be configured such that the first and second connection interfaces are adapted to each other for connecting the respective section cavities in an air-tight and / or light-tight manner. The connection between the section cavities is preferably both air-tight and light-tight. In the sense of the present invention, being both air-tight and light-tight is understood to mean that the respective section cavities are provided with air-tightness against the environment. Since each section cavity can easily be provided with air-tight and / or light-tightness, the connection between the respective sections is a weak point along the beamline in terms of both air-tight and light-tightness. However, by providing first and second connection interfaces that are appropriately adapted to each other, it is possible to ensure an air-tight and / or light-tight connection between two adjacently arranged sections. The appropriate adaptation of the connection interfaces may, for example, be achieved by providing each connection interface with a protrusion and a groove or by providing a dedicated sealing means. Furthermore, precise machining of the connection interfaces supports the adaptation.

[0021] In an improvement of the beamline according to the present invention, both the first connection interface and the second connection interface may have one or more arrangement spaces for accurately fitting alignment elements of the beamline to align the section pairs of the adjacently arranged optical sections and / or guiding sections. In other words, the precise fitting of the alignment elements in the respective arrangement spaces of each connection interface allows very precise relative positioning of the adjacently arranged optical sections and / or guiding sections, thereby allowing the two elements of the section pair to be accurately aligned, which automatically improves the airtightness and light-tightness of the connection, respectively.

[0022] According to further improved embodiments of the beamline according to the invention, the arrangement spaces surround each of the section openings and the alignment elements are ring-shaped and / or the arrangement spaces are bores and the alignment elements are screws or bolts for fixing each of the section pairs of the adjacently arranged optical and / or guiding sections to one another. This list is not exhaustive and can be extended by further embodiments of arrangement spaces and alignment elements shaped accordingly that precisely fit into the arrangement spaces at the respective first and second connection interfaces.

[0023] Furthermore, the beamline according to the present invention may be improved by having the first connection interface include an elastomeric seal surrounding the opening of the first section and / or the second connection interface include an elastomeric seal surrounding the opening of the second section to provide an airtight and / or lighttight connection between the respective section cavities. As described above, dedicated sealing means can be used to provide the airtight and / or lighttight connection. Elastomeric seals, such as O-rings, are suitable as such sealing means. By surrounding the respective openings at the ends of the sections, the respective openings can be reliably sealed. The elastomeric seals can be provided at one or both connection interfaces, e.g., with different radii. Furthermore, these elastomeric seals can be supported by respective grooves in the connection interfaces, both of the connection interfaces carrying the elastomeric seals and / or the complementary connection interface.

[0024] The beamline according to the present invention may further be characterized in that the one or more optical sections comprise an optical element arranged in each of the section cavities, the optical element being capable of modifying and / or controlling one or more properties of a laser beam entering the section cavity through the first section opening, such that the modified laser beam exits the section cavity through the second section opening. In other words, suitable means for mechanically supporting the respective optical element are provided within the section cavity of each optical section. By making the laser beam, whose properties have been modified and / or controlled by the optical means, exit the section cavity again through the second opening, blocking of the laser beam by each optical section can be prevented.

[0025] For example, the optical element can be a plane mirror and the modified property of the laser beam can be the direction of the laser beam changed by simple reflection on the mirror, which allows corner pieces of the beam line to be easily provided, especially without the risk of blocking the laser beam.

[0026] According to a further refinement, the beamline according to the invention may be configured such that the optical elements are able to modify and / or control the laser beam, which enters the section cavity substantially parallel to the central axis of the first section opening, so that it exits the section cavity substantially parallel to the central axis of the second section opening. In other words, since the guiding section does not modify the alignment of the laser beam, by providing optical elements respectively configured in all optical sections, a laser beam which enters the beamline according to the invention parallel to the central axis at the source end remains parallel to the central axis actually present in the respective part of the beamline throughout the beamline, and further exits the beamline at the chamber end parallel to the central axis of the last section cavity of the last section of the beamline.

[0027] In addition, the guidance sections between each optical section of the beamline can be of any length, since they do not affect the parallel alignment of the laser beam with respect to its respective central axis. This allows for great flexibility in routing the beamline from the laser source to the reaction chamber. In particular, the overall beamline shape can be changed and reconfigured without affecting the laser beam shape, the beamline performance, or the final intensity distribution. The optical path remains unaffected. This is especially true for rotationally symmetric laser beams.

[0028] Furthermore, the beamline according to the present invention may be improved by having the central axis of the first section opening perpendicular to the central axis of the second section opening. Thus, the direction of the laser beam can be changed by 90° through each optical section. Because the laser beam is parallel to the central axis at the second opening at the downstream end of each optical section, all other properties of the laser beam, such as its shape, spatial intensity distribution, and / or focal length, can remain unaffected. However, if the optical elements have adequate capabilities and / or if more optical elements are present in each section cavity of the optical element, it may be possible to change and / or control other properties of the laser beam in addition to the changed direction.

[0029] In another embodiment, the beamline according to the present invention may be configured such that the section cavities of the one or more guiding sections extend linearly from the first section opening to the second section opening along a common central axis of the first and second section openings. In other words, the section cavities have a tubular shape bounded by the section openings that are parallel to each other and share a common central axis. The common central axis preferably also forms the central axis of the tubular section cavities. Such a configuration easily ensures that each guiding section does not affect the parallel alignment of the laser beam with respect to its respective central axis.

[0030] Furthermore, the beamline according to the present invention may be characterized in that the beamline has a laser inlet, which forms the source end, has a second connection interface, and is gas-tight and / or optically connectable to the laser light source; and / or the beamline has a chamber outlet, which forms the chamber end, has a first connection interface, and is gas-tight and / or optically connectable to the reaction chamber. The provision of the laser inlet allows the source end of the beamline to be gas-tight and / or optically connected to the laser light source and to the first connection interface at the upstream end of the first section of the beamline, respectively. Similarly, the provision of the chamber outlet allows the chamber end of the beamline to be gas-tight and / or optically connected to the reaction chamber and to the second connection interface at the downstream end of the last section of the beamline, respectively. This allows gas-tight and / or optically connected connections at both ends of the beamline. In other words, the beamline according to the present invention can be configured to provide an environmentally gas-tight and optically tight connection between the laser light source and the reaction chamber.

[0031] Additionally, the beamline according to the present invention may be improved by including a bellows at the chamber exit and / or at the laser entrance. A bellows is an elastic element having a cavity, and as part of the chamber exit and / or laser entrance, shields the area between the last optical section or guidance section of the beamline and the reaction chamber and / or between the first optical section or guidance section of the beamline and the laser system, preventing leakage of laser light and / or gas in this area while mechanically isolating the beamline from the reaction chamber and / or the laser system. This can isolate vibrations between the beamline and the reaction chamber and / or the laser system and avoid other problems such as mechanical stress due to thermal expansion.

[0032] According to a further improved embodiment of the beamline of the present invention, the chamber exit has a chamber window that can be positioned on the flange of the reaction chamber. Thus, the beamline terminates at the chamber window. Because the chamber window can be positioned on the flange of the reaction chamber, no additional fixing or sealing means are required to position the chamber exit of the beamline of the present invention on the reaction chamber of the TLE system, particularly on the chamber window of the reaction chamber. The chamber exit and its chamber window already have all the means for sealing the reaction chamber of the TLE system, such as an elastomeric seal such as an O-ring and / or a circular sharp edge forming a knife seal. This simplifies the setup of the TLE system.

[0033] The beamline of the present invention may further be characterized in that it includes a gas system for creating a flow of purge gas within the beam cavity. For some laser beams, absorption in the atmosphere along the beamline can be problematic. For example, water vapor strongly absorbs infrared laser beams, particularly those with wavelengths around 10 μm. A gas system as part of the beamline of the present invention can be used to solve this problem, since it can create a flow of purge gas within the beam cavity of the beamline. The purge gas can preferably be selected with respect to the wavelength of the laser beam guided within the beamline to minimize the risk of absorption of the laser beam en route from the source end to the chamber end of the beamline.

[0034] Additionally, the beamline may be improved by connecting one or more inlets of the gas system for injecting the purge gas into the beam cavity and one or more outlets of the gas system for evacuating the purge gas from the beam cavity to the beam cavity such that the flow of purge gas is supplied throughout the beam cavity between the source end and the chamber end, which respectively represent the beginning and end of the beam cavity. At least one appropriately positioned inlet of the gas system and at least one equally appropriately positioned outlet of the gas system provide a flow of purge gas throughout the beam cavity. The direction of the purge gas flow is not critical and can be selected arbitrarily. According to a first alternative refinement, the beamline according to the invention may be configured such that the inlet is connected to the laser entrance and the outlet is connected to the chamber exit. In that case, along the propagation of the laser beam, the laser entrance forms the first element of the source end and the chamber exit forms the last element of the chamber end. Thus, by arranging the inlet of the gas system at the laser entrance and the outlet of the gas system at the chamber exit, ensuring a flow of purge gas through the complete beam cavity can be further improved.

[0035] According to a second alternative refinement, the beamline according to the invention may be configured such that the outlet is connected to the laser entrance and the inlet is connected to the chamber exit. Again, along the propagation of the laser beam, the laser entrance forms the first element of the source end and the chamber exit forms the last element of the chamber end. Thus, by providing the gas system outlet at the laser entrance and the gas system inlet at the chamber exit, ensuring a flow of purge gas through the complete beam cavity can also be further improved.

[0036] According to a third alternative refinement, the beamline according to the invention may be configured such that one inlet is connected to the laser entrance, one inlet is connected to the chamber exit, and one outlet is connected to the beam cavity between the source end and the chamber end, or one outlet is connected to the laser entrance, one outlet is connected to the chamber exit, and one inlet is connected to the beam cavity between the source end and the chamber end. Again, along the propagation of the laser beam, the laser entrance forms the first element at the source end, and the chamber exit forms the last element at the chamber end. Therefore, by providing one inlet each at the laser entrance and the chamber exit, and one outlet connected to the beam cavity somewhere in between, or vice versa, ensuring a flow of purge gas through the complete beam cavity can be further improved.

[0037] Furthermore, the beamline according to the present invention may be improved by using dry air or pure nitrogen as a purge gas. Dry air and pure nitrogen are purge gases that are substantially free of water vapor. Therefore, particularly for infrared laser beams with a wavelength of approximately 10 μm, dry air and pure nitrogen are suitable purge gases for preventing absorption of the laser beam in the beamline according to the present invention.

[0038] In yet another embodiment, the beamline according to the present invention may be characterized in that the housings of each of the one or more optical sections and the one or more linear guide sections are mechanically rigid or at least essentially rigidizable, and the first and second connection interfaces are adapted to each other to provide a mechanically rigid connection. In other words, the spatial orientation and position of the upstream and downstream ends of each of the optical and guide sections relative to each other are fixed or can be fixed and do not change under mechanical stress. Additionally, since the connection between each of the first and second connection interfaces is also mechanically rigid, this relative spatial positioning and orientation fixation is also possible for the source and chamber ends of the beamline. In other words, the beamline according to the present invention can be provided autonomously.

[0039] Furthermore, the beamline may be configured such that the housing of the one or more straight guidance sections is a tubular aluminum extrusion. A tubular extrusion can offer the advantage of high stiffness due to its tubular shape, particularly against torque around its longitudinal axis. Ribs along the tubular shape and circumferential axis can further increase the stiffness. Additionally, using aluminum as a material allows the sections to be lightweight, have excellent thermal conductivity, and avoid localized bending due to localized thermal expansion.

[0040] Furthermore, the beamline according to the present invention may be improved by providing grooves on the outer surface of the housing for fastening to a support structure. As mentioned above, the beamline according to the present invention can be provided so that it is entirely self-supporting. However, it may be advantageous to provide support for the beamline as a whole, for example, to ensure a fixed relative positioning and / or orientation of the entire beamline with respect to the laser source and / or reaction chamber, and / or if the beamline itself must be supported to prevent it from tipping over as a whole. Providing grooves on the outer surface of the housing, in particular in an extruded tubular aluminum section, allows for easy fastening to an additional external support.

[0041] In another embodiment, the beamline according to the present invention may be configured such that one or more threaded holes are provided in the first connection interface and / or the second connection interface of the housing. The threaded holes may be provided in the housings of both the optical section and the guidance section, respectively. In particular, screws may be inserted and fixed into such threaded holes to connect the first connection interface and the second connection interface to each other. In particular, screws in the threaded holes are a simple and reliable way to provide a mechanically rigid connection between each first connection interface and each second connection interface.

[0042] The beamline of the present invention may be further improved by arranging two or more screw holes in a rotationally symmetric pattern around each of the first and / or second section openings, particularly a rotationally symmetric pattern of 180°, 120°, 90°, 72°, 60°, 45°, 40°, 30°, 20°, 10°, or 5°, around the central axis of each of the first and / or second section openings. The number of screw holes thereby defines the rotationally symmetric pattern, and vice versa. In other words, any pair of sections sharing this positioning of screw holes can be positioned relative to one another in several different specific orientations, each defined by this embodiment of the rotationally symmetric pattern. Especially for rotationally symmetric laser beams, such rotations do not affect the shape of the beam at the sample position or elsewhere along the beamline. Therefore, the beamline can be "bent" in a variety of different ways depending on the space available in the laboratory or manufacturing facility, the placement of the laser source, the size and location of the reaction chamber, etc.

[0043] Additionally or alternatively, the beamline according to the present invention may be configured such that the first and second connection interfaces are rotationally symmetric, whereby the beamline comprises clamping means for securely fixing a pair of adjacently arranged optical and / or guiding sections. In this embodiment, either the optical or guiding section, or the two sections as a mixed pair, constitute a rotationally symmetric connection interface. Fixing these sections by clamping means allows for any relative rotation between these sections. All the advantages described in the previous paragraph are also provided by the embodiment described in this paragraph, but in addition, the two sections can also be freely rotated relative to each other. This allows for even greater flexibility when setting up the beamline according to the present invention.

[0044] Furthermore, the beamline according to the present invention may be characterized in that the surfaces of the section cavities are anodized to provide an oxide layer on the surfaces of the section cavities. Anodizing the surfaces of the section cavities ensures a fairly thick oxide layer on the surfaces, especially when the respective optical or guiding sections are made of aluminum. This, together with the low divergence of the laser beam along the optical path and therefore the low angle of incidence on the wall surfaces, leads to good absorption of stray light at the surfaces of the respective section cavities, thereby reducing stray light at the source or substrate position in the reaction chamber. In particular, laser light with a wavelength around 10 μm, which is most effective for substrate heating of most materials, is absorbed particularly efficiently by aluminum oxide.

[0045] According to another embodiment, the beamline comprises one or more optical sections adapted to adjust the following characteristics of the laser beam: -direction; -size; -shape; -polarization; - focal length; and -Intensity distribution may be configured to modify and / or control one or more of: This list is not exhaustive and can be expanded with additional properties of the laser beam. By modifying and / or controlling one or more of the above properties of the laser beam in the beamline, a laser beam having selected and controlled properties can be provided in the reaction chamber suitable for evaporating and / or sublimating a source material or heating a substrate material.

[0046] For the improvement, the beamline may further comprise one or more optical sections, each of said optical elements comprising: - Plane mirror; -Focusing mirror; - Defocusing mirror; - axicon mirror; -Freeform mirror; -Bragg Miller; - a diffraction mirror or a diffraction grating; and -Aperture The present invention may be characterized by having one or more of the following: This list is not exhaustive and can be extended with further optical elements for modifying and / or controlling the properties of the laser beam. In particular, the above list includes mirrors for modifying and / or controlling the properties, which are best suited for use with infrared laser beams and are often used in TLE systems. However, most of the optical elements listed above as mirrors can also be configured as transmissive elements, such as lenses, if this is appropriate for the actual application, and in particular for the laser beam used.

[0047] Furthermore, the beamline may be further improved by machining the active parts of the optical elements of each of the one or more optical sections from a monolithic block of metal, particularly copper. Metal, particularly copper, can be machined with extremely high precision, and such machined surfaces have high reflectivity for most laser beams typically used in TLE systems. Another example of a suitable metal is aluminum. Therefore, machining the active parts of the optical elements from a monolithic block of metal results in optical elements with high precision and high reflectivity.

[0048] According to another improved embodiment of the beamline according to the invention, the optical elements of the one or more optical sections comprise actively adjustable mirrors. "Actively adjustable" in the sense of the present invention means that the spatial orientation and / or spatial shape of the mirrors can be actively changed, in particular during operation of the laser source. Thus, the respective properties that are changed and / or controlled by the respective optical elements can be actively adjusted during operation of the TLE system.

[0049] Furthermore, the beamline according to the present invention may be improved by adjusting the spatial orientation of the actively adjustable mirror by means of adjustment screws and / or by having a reflective film on a cushion that can be filled with an adjustment fluid. Adjustment screws, particularly three adjustment screws, are a simple and reliable way to adjust the spatial orientation of the adjustable mirror. Furthermore, the spatial shape of the reflective film on the cushion strongly depends on the filling amount in the cushion. Therefore, adjusting the filling amount of the cushion is likewise a simple and reliable way to adjust the spatial shape of the adjustable mirror.

[0050] According to an additional refinement, the beamline according to the present invention may be configured such that the adjustment screws and / or the adjustment connectors for the adjustment fluids are accessible from outside the housing of each of the optical sections. In either case, the orientation or shape of the adjustable mirrors can be actively adjusted without needing direct access to the active parts of the adjustable mirrors, in other words, without needing to open each optical section of the beamline. This makes it very easy to ensure that each optical element can be actively adjusted during operation of the TLE system.

[0051] Additionally, the beamline may be characterized in that the one or more optical sections have cooling means for actively cooling each of the optical elements. Metal mirrors preferably used as optical elements in the beamline according to the present invention are highly reflective. Nevertheless, these metal mirrors absorb only a small portion of the incident laser light. Active cooling of the mirrors compensates for the energy deposition caused by absorbing the incident laser light, thus preserving the intended optical properties of each optical element.

[0052] Furthermore, apertures are also optical elements within the meaning of the present invention. They can also be machined from a block of metal, in contrast to mirrors, which are used to intentionally block part of the laser beam. A large amount of laser energy is often unavoidably deposited in the bulk of the aperture. Especially in the case of apertures, active cooling is advantageous to preserve the properties of the aperture, for example to prevent changes in shape due to thermal stress.

[0053] In a specialized embodiment, the beamline may be configured such that the cooling means have cooling ducts for the coolant machined into and / or within a monolithic block of metal forming the active part of each of the optical elements. As mentioned above, machining the active parts of the optical elements from a monolithic block of metal allows the optical elements to be obtained with high precision. In addition, metals, especially copper and aluminum, have high thermal conductivity. By providing cooling ducts within the bulk of the monolithic block of metal, the thermal energy deposited by the incident laser beam can be transported in a very efficient manner.

[0054] Additionally, the beamline may be characterized by having beam diagnostic means for measuring properties of the laser beam. The main purpose of the beamline according to the invention is to deliver a laser beam with selected properties up to and within the reaction chamber. In many cases, TLE systems are equipped with diagnostic means for measuring these properties. As mentioned above, the beamline according to the invention may be composed of optical sections with adjustable, in particular actively adjustable, optical elements. It may therefore be advantageous to directly measure one or more properties of the laser beam within the beamline before it enters the reaction chamber, for example, to provide direct feedback on adjustments applied to the adjustable optical elements. Such measurements can be performed by beam diagnostic means provided within the beamline itself.

[0055] According to a possible embodiment of the beamline according to the invention, the beam diagnostic means comprises a pyrometer for measuring the temperature of an optical element of one of the one or more optical sections. By measuring the temperature of the optical element, the deposition of energy absorbed from the incident laser beam can be measured. Thus, the intensity of the incident laser beam can be calculated. Preferably, the pyrometer performs temperature measurements with a spatial resolution that allows the calculation of a spatially resolved intensity profile of the incident laser beam.

[0056] Additionally or alternatively, the pyrometers can be used to measure the temperature of a substrate or source heated by the laser beam. To this end, the pyrometers are preferably positioned to probe the substrate or source along the beam axis of the laser beam. This can be achieved, for example, by placing a semi-transparent optical element, such as a beam splitter or a Bragg mirror, in the path of the laser beam, and appropriately positioning the respective pyrometer behind the Bragg mirror or semi-transparent optical element.

[0057] In addition, the Bragg mirror has the characteristic of reflecting only a specific narrow wavelength band. Since the laser light outside this band is transmitted through the Bragg mirror, it can be directly measured by a pyrometer. In this case, the substrate temperature can also be directly measured by the pyrometer for at least a portion of the laser beam transmitted through the Bragg mirror.

[0058] Furthermore, the beam line may be further improved by configuring an optical element, in particular a Bragg mirror, of one of the one or more optical sections that changes the direction of the laser beam by 90° to be removable, an additional beam line element being positioned and / or positionable at the position of the optical element or along the original direction of the laser beam, and the beam diagnostic means having a detector positioned at the measurement position of the additional beam line element. By removing the optical element, the laser beam is no longer reflected and propagates straight through the additional beam line element, where it can be examined by a detector positioned in the additional beam line element for this purpose. The detector can preferably be positioned directly in the path of the laser beam, thereby allowing direct measurement of the laser beam properties.

[0059] Furthermore, the beamline according to the present invention may be configured such that the one optical section is the last optical section before the end of the chamber, and the measurement distance of the measurement position relative to the position of the removed optical element is selected according to, and preferably equal to, the working distance of the removed optical element relative to the substrate or source in the reaction chamber. The working distance is the distance between the optical element of the last optical section and the destination of the laser beam in the reaction chamber, i.e., the source or substrate. In particular, for a laser beam aligned parallel to the central axis of the beamline and parallel to the central axis of the first opening of at least one of the optical sections, this directs the laser beam to the measurement position with characteristics directly related to the characteristics of the laser beam that would be present at the working distance. When the measurement distance and the working distance are equal, these characteristics are substantially identical and only vary with small distortions due to the chamber window. Measurement of the laser beam characteristics at the destination in the reaction chamber can be performed without opening the reaction chamber.

[0060] The beamline according to the invention can be further improved by the fact that the detectors are cameras and / or beam monitors and / or canvas and / or thermal paper. This list is not exhaustive and can be extended with other suitable detectors. All listed detectors can be used to investigate spatially resolved images of the intensity distribution of the laser beam.

[0061] In another embodiment of the beamline according to the invention, the beamline is a modular beamline consisting of several optical and / or guidance sections as modules. In particular, all sections, i.e., optical and guidance sections, share the same first and second connection interfaces, respectively, so that all sections can be arranged in any order. Furthermore, it is also possible without problems to add and / or remove one or more sections in order to change the setup of the beamline according to the invention. This allows providing several possible implementations of the beamline according to the invention.

[0062] Additionally, the beamline according to the present invention can be further improved by a pair of optical sections for redirecting and / or controlling the laser beam being arranged relative to one another using the respective first and second connection interfaces to form a modular beamline junction, the modular beamline being rotatable and / or pivotable at the junction by rotating the optical sections relative to one another. Since both optical sections forming the modular beamline junction are capable of redirecting and / or controlling the laser beam, by rotating the optical sections relative to one another, it is also possible to arbitrarily change the initial direction of the laser beam at the first section opening of the optical element upstream of the junction to the resulting direction of the laser beam at the second section opening of the optical element downstream of the junction. Depending on the change in the respective directions of the laser beams provided by each of the two optical sections, the modular beamline junction constructed as described in this paragraph can change the direction of the laser beam.

[0063] According to a further refinement of the embodiment of the beamline according to the invention described above, the optical section is configured according to claim 6 of the invention. This in particular comprises that each of the two optical sections forming the junction has an optical element arranged in the respective section cavity, which optical element is able to change and / or control the direction of the laser beam such that a laser beam entering the respective section cavity parallel to the central axis of the first section opening exits the respective section cavity parallel to the central axis of the second section opening, the central axis of the first section opening being perpendicular to the central axis of the second section opening in both optical sections. In other words, each of the two optical sections forming the junction changes the direction of the laser beam by 90°.

[0064] Furthermore, the laser beam enters the junction substantially parallel to the central axis of the first section opening of the first optical section of the junction, and similarly exits the junction substantially parallel to the central axis of the second section opening of the second optical section of the junction. The latter is particularly independent of both the relative rotational position of the two optical sections forming the junction and the relative rotational orientation of each optical section with the next adjacently arranged guidance section or optical section in the modular beamline. Thus, the initial direction of the laser beam can be changed to a resulting direction that consists essentially of each solid angle, particularly limited only by the dimensions of the optical sections perpendicular to the respective direction of the laser beam, without changing the optical path of the beamline.

[0065] According to a second aspect of the present invention, the above object is achieved by a laser system for a thermal laser evaporation (TLE) system. The laser system comprises a laser source for providing a laser beam and a beamline for directing the laser beam from the laser source to a reaction chamber of the TLE system. The laser system according to the present invention is characterized in that the beamline is configured according to the first aspect of the present invention. In particular, the beamline has a source end located at the laser source, and the laser beam provided by the laser source enters the beamline from the source end and is directed within the beamline to a chamber end located at and connectable to a reaction chamber of the TLE system. In summary, the laser system according to the second aspect of the present invention provides all the features and advantages described above with respect to the beamline according to the first aspect of the present invention.

[0066] Furthermore, the laser system according to the present invention may be characterized in that the laser system includes a support structure, and the laser source and the beam line are disposed on the support structure. By providing a common support structure for the laser source and the beam line, the relative positions of the elements of the laser system can be fixed. In particular, it is not necessary to ensure fixation by disposing the source end of the laser beam on and / or above the laser source. In addition, even if the beam line is provided as a freestanding structure, disposing the beam line on an external support can prevent the beam line as a whole from tipping over.

[0067] Furthermore, in the laser system according to the present invention, the laser light source may be configured to provide an infrared laser beam having a wavelength between 0.1 μm and 1000 μm, preferably 10 μm, and in particular, the laser light source may be a CO laser light source. Infrared lasers can be provided at high intensities and are commonly used in TLE systems, particularly for continuous operation. On the other hand, ultraviolet lasers are suitable for evaporating and / or sublimating various source materials. Therefore, using a laser light source that provides a laser beam having a wavelength in the ultraviolet (UV) or infrared (IR) region makes the use of the laser system according to the present invention in a TLE system more suitable.

[0068] According to a third aspect of the present invention, the above object is achieved by a thermal laser evaporation (TLE) system comprising a reaction chamber that can be filled with a reaction atmosphere, a substrate disposed in the reaction chamber, one or more sources disposed in the reaction chamber, and a laser system for providing a laser beam for evaporating and / or sublimating material of the source and / or for heating material of the substrate. The TLE system according to the present invention is characterized in that the laser system is configured according to the second aspect of the present invention. The laser system according to the second aspect of the present invention comprises a beamline according to the first aspect of the present invention. In summary, the TLE system according to the third aspect of the present invention includes all the advantages already described above for the beamline according to the first aspect of the present invention and for the laser source according to the second aspect of the present invention.

[0069] In a TLE system, a laser can be used to both evaporate or sublimate a source material or heat a substrate material. Such TLE systems are commonly known. The source material evaporated and / or sublimated by the incident laser beam is deposited on a substrate, which serves as a target. Additionally or alternatively, the laser beam can be used to heat the substrate material. The source material is provided by source elements arranged in a source within the reaction chamber; the source elements may be one or more, and may in particular provide the same and / or different source materials. The laser beam is incident on a face of the source element (most often the top face) and provides a flux of evaporated or sublimated source material.

[0070] The source is placed in a reaction chamber that can be sealed to the ambient atmosphere and filled with a reaction atmosphere, which can be a vacuum, in particular 10 -12 The pressure may be as low as 100 kPa or less, or may consist of a reactive gas at a pressure appropriate for the material to be deposited, e.g., a reactive gas that provides oxygen for the deposition of oxides of evaporated and / or sublimated elemental or compound source materials. The maximum value tested so far at a working distance of 60 mm is 10 -2 hPa and high. 10-2 Since deposition was possible without problems at 1000 kPa, it is likely that even higher values ​​are possible.

[0071] For both purposes of the laser beam, i.e. for evaporation and / or sublimation of the target material and heating of the substrate material respectively, the laser beam is generated by a laser source of the laser system according to the second aspect of the invention and is guided from the laser source to the reaction chamber by a beam line according to the first aspect of the invention. The use of said beam line according to the first aspect of the invention may also offer the possibility to modify and / or control the properties of the respective laser beam.

[0072] The invention will now be described in detail by way of embodiments, with particular reference to the drawings identified below. [Brief explanation of the drawings]

[0073] [Figure 1] FIG. 1 is a diagram showing a TLE system according to the present invention. [Figure 2] FIG. 2 is a first partial view of a beamline according to the present invention. [Figure 3] FIG. 3 is a second diagram showing the beamline of FIG. [Figure 4] FIG. 4 shows a laser system according to the present invention having the beamline of FIG. [Figure 5] FIG. 5 is a diagram illustrating a laser beam guided by the beamline of FIG. [Figure 6] FIG. 6 shows a diagram of the guidance section of a beamline according to the present invention. [Figure 7] FIG. 7 shows a possible arrangement of joints in a modular beamline according to the present invention. [Figure 8] FIG. 8 is a diagram showing an example of beam diagnosis of a beamline according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0074] 1 shows a schematic diagram of a TLE system 300 according to the present invention. In particular, the TLE system 300 comprises a reaction chamber 310 and a laser system 200 according to the present invention, which itself comprises a support structure 212, a laser source 210, and a beamline 10 according to the present invention.

[0075] Reaction chamber 210 is filled with a reaction atmosphere 312. Additionally, a source 314 having a material to be evaporated and / or sublimated and a substrate 316 having a material to be coated are disposed within reaction chamber 310. In the illustrated embodiment of TLE system 300, a laser beam 220 provided by laser system 200 is used to evaporate and / or sublimate the material of source 314. However, substrate 316 may likewise be heated by a laser beam 220, which may be provided by laser system 200 suitably constructed in accordance with the present invention.

[0076] As already mentioned, the laser system 200 comprises a laser source 210 which generates a laser beam 220. The laser beam 220 may preferably be an infrared laser beam 220 having a wavelength of, for example, about 10 μm. To guide the laser beam 220 from the laser source 210 to the reaction chamber 310, a beamline 10 according to the present invention is used. A common support structure 212 of the laser system 200 supports both the laser source 210 and the beamline 10, respectively, thereby ensuring, on the one hand, a secure and mechanical support of the above elements of the laser system 200, and, on the other hand, a fixed relative positioning of the laser source 210 and the beamline 10 with respect to each other.

[0077] The beamline 10 extends between a source end 20 and a chamber end 30. The source end 20 is formed by a laser inlet 22, which is gas-tightly and light-tightly connected to a laser source 210. The laser inlet 22 already includes a plane mirror 82 for deflecting the laser beam 220. Similarly, the chamber end 30 is formed by a chamber outlet 32, which is also gas-tightly and light-tightly connected to a reaction chamber 310. In particular, the chamber outlet 32 ​​includes a chamber window 36 that can be located in a respective flange of the reaction chamber 310.

[0078] In the illustrated embodiment, the beamline 10 is a modular beamline 10 consisting of two guiding sections 52 and two optical sections 50. All sections 50, 52 share the same connecting interfaces 64, 70 (see FIGS. 2 and 6) and can be arranged adjacent to each other in any order. In particular, all sections 50, 52 are mechanically rigid or at least can be made inherently rigid. Furthermore, the sections 50, 52 can be connected in pairs by a suitably configured first connecting interface 64 at the upstream end 60 of each section 50, 52 and a second connecting interface 70 at the downstream end 66 of each section 50, 52, which connection is also mechanically rigid (FIGS. 2 and 6). In other words, the beamline 10 according to the present invention is preferably self-supporting.

[0079] The optical section 50 is used to modify and / or control the properties of the laser beam 220, such as the direction of the laser beam 220 as shown. The steering section 52 extends linearly straight. In summary, the beamline 10 according to the present invention provides an airtight and lighttight connection between the laser source 210 and the reaction chamber 310, where the laser beam 220 is directed within the beamline 10 and further properties of the laser beam 220 are modified and / or controlled to meet the operational requirements of the TLE system 300.

[0080] 2 to 4 illustrate possible embodiments of a beamline 10 according to the present invention and a laser system 200 according to the present invention having the beamline. Furthermore, FIG. 5 shows a laser beam 220 guided through the beamline 10, illustrating some of the changes in the characteristics of the laser beam 220 on its way through the beamline 10. The following description will be given in conjunction with FIGS. 2 to 5.

[0081] FIG. 2 specifically illustrates the optical section 50 of the beamline 10. To better visualize the laser beam 220, the guidance section 52 (see FIGS. 3 and 4) is not shown, allowing the three downstream ends 66 of the optical section 50 to be shown. Again, because the beamline 10 is modular, the visible downstream end 66 is representative of all downstream ends 66 and corresponds to the appropriately configured upstream ends 60 (see FIG. 6) of all sections 50, 52. All downstream ends 66 have a second section opening 68 of the respective section cavity 56 and a second connection interface 70 with an elastomeric seal 72 surrounding the second section opening 68 for an airtight and lighttight connection.

[0082] Also shown are the laser entrance 22, the chamber exit 32, and, in the illustrated embodiment, a substrate 316 onto which the laser beam 220 is irradiated. The chamber exit 32 has a chamber window 36 that can be disposed on each flange of the reaction chamber 310 of the TLE system 300 (see FIG. 1), similar to the embodiment shown in FIG. 1. The illustrated chamber exit 32 also has a bellows 34 for mechanically isolating the laser system 200, including the beamline 10, from the reaction chamber 310, for example, to prevent transmission of vibrations between parts of the TLE system 300.

[0083] The illustrated beamline 10 has six optical sections 50, each serving as mechanical support for an optical element 80 for modifying and / or controlling the properties of the laser beam 220. These optical elements 80 are also illustrated in FIG. 5. Note that all optical elements 80 are provided as mirrors, with the exception of aperture 94, which is illustrated as a lens in FIG. 5 for illustrative purposes only. All optical elements 80 provided as mirrors reflect the incident laser beam 220 by 90°, thus at least modifying the direction of the laser beam 220.

[0084] Preferably, these optical elements 80, or at least the active part of each optical element 80, are machined from a monolithic block of metal, in particular copper or aluminum. This also applies to the mirrors 82, 84, 86, 88, 90 and the aperture 94. This allows the optical elements 80 to be provided with high precision in terms of their optical properties. Furthermore, metals, and in particular copper, have a high thermal conductivity. This allows the laser energy deposited on each optical element 80 to be well distributed within the optical element 80. Furthermore, cooling of the metal block is also easy; in particular, cooling ducts for each cooling means 100 can be machined directly into the monolithic metal block forming the optical element 80.

[0085] Furthermore, FIG. 5 illustrates on the right side the laser beam 220 passing continuously through the optical element 80, and on the left side an intensity cross section showing the local intensity distribution of the laser beam 220 next to the optical element 80.

[0086] 5, the laser beam 220 is parallel to the central axis C throughout its travel within the beamline 10. This is particularly provided by the structure of each optical section 80 such that the laser beam 220, which enters the section cavity 56 of each optical section 50 parallel to the central axis C of the respective first section opening 62 (see FIG. 6), exits the section cavity 56 parallel to the central axis C of the respective second section opening 68. Furthermore, each section cavity 56 of the guiding section 52 (see FIGS. 3, 4, and 6) extends linearly from the first section opening 62 to the second section opening 68 along the common central axis C of the first section opening 62 and the second section opening 68 of each guiding section 52.

[0087] Furthermore, the intensity distribution of the laser beam 220 is preferably rotationally symmetric, or has two-fold symmetry if all junctions have an integer multiple of 180° rotation, three-fold symmetry if all junctions have an integer multiple of 120° rotation, four-fold symmetry if all junctions have an integer multiple of 90° rotation, five-fold symmetry if all junctions have an integer multiple of 72° rotation, six-fold symmetry if all junctions have an integer multiple of 60° rotation, or eight-fold symmetry if all junctions have an integer multiple of 45° rotation.

[0088] 2 and 5, the laser beam emitted from the laser source 210 first impinges on the focusing mirror 84. This is followed by the optical section 50, which includes the defocusing mirror 86 as the optical element 80. This first pair of optical sections 50 thus forms a beam telescope, essentially changing the radius and thus the size of the laser beam 220. At least the defocusing mirror 86, and preferably also the focusing mirror 84, are configured as adjustable mirrors, specifically, reflective membranes on cushions. The amount of fluid in the cushions can be adjusted by an adjustment connector 102 accessible from outside the beamline 10. Therefore, by adjusting the filling amount of the cushions of the defocusing mirror 86 and / or the focusing mirror 84, respectively, the size of the laser beam can be actively adjusted during operation of the laser system 200.

[0089] The optical section having the axicon mirror 88 is disposed immediately adjacent to the optical section 50 having the defocusing mirror 86. Thus, the optical section 50 having the defocusing mirror 86 and the optical section having the axicon mirror 88 form the junction 16 of the modular beamline 10. The axicon mirror 88 changes the spatial shape of the intensity distribution of the laser beam 220 (see FIG. 5).

[0090] A further downstream optical section 50 having a complementary axicon mirror 88 formed as a freeform mirror 90 to also function as a focusing mirror 84 undoes the change in intensity distribution of laser beam 220. The freeform mirror 90 is further configured as an adjustable mirror, the spatial orientation of which can be adjusted by means of adjustment screws 100 accessible from outside of beamline 10.

[0091] However, between the two axicon mirrors 88, an optical section 50 having an aperture 94 as the optical element 80 is disposed to selectively cut off the outer portion of the laser beam 220, thereby changing the shape of the intensity distribution of the laser beam 220.

[0092] As mentioned in the previous paragraph, the aperture 94 is used to cut the laser beam 220, in particular by absorbing a portion of the laser beam 220. To prevent damage from the absorbed laser energy, the aperture 94 comprises cooling means 110. The cooling means may consist, for example, of a coolant flowing through cooling ducts in the aperture 94. Preferably, the inlet and / or outlet of the coolant are accessible from outside the beamline 10.

[0093] In the particular embodiment shown, the upstream face of the aperture 94 is coated with an oxide absorbing layer, preferably a rough, plasma-spray coated sapphire layer having a thickness of 0.5 mm, which facilitates absorption of excess laser light from the laser beam 220 by bringing this layer into direct, intimate contact with the fluid cooling body of the aperture 94, thereby efficiently conducting heat to the fluid cooling ducts of the cooling means 110.

[0094] Finally, the last optical section 50 has a Bragg mirror 92 as optical element 80, which on the one hand provides a 90° wavelength-selective reflection of the laser beam 220 and, on the other hand, allows the implementation of a pyrometer 122 as diagnostic means 120 for directly measuring the temperature of the object heated by the laser beam 220 (see Figure 4). Furthermore, the aforementioned optical section 50 with the freeform mirror 90 and the optical section 50 with the Bragg mirror 92 are positioned directly adjacent to each other, thereby forming the second junction 16 of the modular beamline 10.

[0095] In addition to the components of the beamline 20 already shown in FIG. 2, FIG. 3 also shows guide sections 52. All guide sections 52 are disposed between the optical sections 50, thereby forming the beamline 10. The section cavities 56 within the housings 54 of these guide sections 52 connect to the section cavities 56 of the optical sections 50 to form a continuous beam cavity 12 extending from the source end 20 of the beamline 10 to the chamber end 30 of the beamline 10. In particular, the beam cavity 12 is an airtight and light-tight space. Therefore, the beam cavity 12 can be supplied with a flow of purge gas 42, such as pure nitrogen and / or dry air, supplied by a gas system 40 and flowing from an inlet 44 at the laser entrance 22 to an outlet 46 at the chamber exit 32. However, other setups of the gas system 40, not shown, are possible, such as providing an inlet 44 at the chamber exit 32 and an outlet 46 at the laser entrance 22, or providing an inlet 44 or outlet 46 somewhere within the beam cavity 12, with an outlet 46 or inlet 44, respectively, at one or both ends of the beam cavity 12.

[0096] Finally, FIG. 4 shows the laser source 210 and the previously mentioned pyrometer 122.

[0097] FIG. 6 shows a possible embodiment of the guide section 52, in which the housing 54 is provided as an aluminum extrusion. FIG. 6A shows an isometric view, and FIG. 6B shows a cross-sectional view of the guide section 52. In particular, FIG. 6A shows the upstream end 60 of each guide section 52, with its first section opening 62 providing access to the section cavity 56 of the guide section 52, which essentially forms part of the beam cavity 12 of the beamline (see FIGS. 2-4). At least a surface 58 of the section cavity 56 is preferably anodized to provide a relatively thick oxide layer for absorbing scattered portions of the laser beam 220.

[0098] Furthermore, a first connection interface 64 is arranged at the upstream end 60. The first connection interface 64 has, for example, an elastomer seal 72 (see FIG. 6B ) surrounding the first section opening 62 and threaded holes 76 for an airtight and lighttight connection to a second connection interface 70, which is suitably constructed at the downstream end 66 of the optical section 50 (see FIG. 2 ) or another guiding section 52. The threaded holes 76 are arranged in a 90° rotationally symmetrical pattern at the upstream end 60. Grooves 74 in the housing 54 of the guiding section 52 allow a secure and particularly easy fastening to an external support structure 212 (see FIG. 1 ).

[0099] 7 illustrates six exemplary configurations of the junction 16 of the modular beamline 10 according to the present invention, shown in A-F. The junction 16 is formed by a pair of optical sections 50 that redirect and / or control the laser beam 220, and these optical sections 50 are arranged relative to one another using their respective first and second connecting interfaces 64 (not shown) and 70 (see FIG. 2). Each optical section 50 can redirect the laser beam 220 by 90°, so that the laser beam 220 remains parallel to a central axis C that exists spatially throughout the junction 16. By rotating and / or pivoting the junction 16, nearly any solid angle can be reached within the modular beamline 10, depending on the relative rotational orientation of the two optical sections 50 relative to one another and the relative rotational orientation of each optical section 50 relative to the adjacently disposed guiding section 52. This is limited only by the size of the optical sections 50 that form the junction 16, which are perpendicular to the laser beam 220 and thus to their respective central axes C.

[0100] Again, the possible angular increments shown in Figure 7 are limited to multiples of 90° for clarity of example. When using bolts and screw holes 76 (see Figure 6), other integer divisions of 360° are possible, such as 180°, 120°, 72°, 60°, 45°, 30°, 20°, 10°, 5°, etc. When using other methods of connecting the optical section 50 and / or the guide section 52, such as clamping means, any angle of rotation is possible at each connection surface, and in the exemplary shape of Figure 7, any angle and orientation is possible between the first and second guide sections 52.

[0101] In addition to or instead of the pyrometer 122 shown in Fig. 4, other possibilities for beam diagnostic means 120 are also conceivable as part of the beamline 10 according to the invention, one of which is shown in Fig. 8. Fig. 8A shows the working mode of a TLE system 300 respectively equipped with a beamline 10, and Fig. 8B shows the same TLE system 300 in measurement mode.

[0102] In the working mode (FIG. 8A), the laser beam 220 is deflected 90° by the optical elements 80, particularly the Bragg mirror 92, of the final optical section 50 of the beamline 10 and is placed within a section cavity 56, which is part of the beam cavity, and is surrounded by the housing 54 of the optical section 50. After deflection, the laser beam 220 passes through a chamber window 36, which is part of the illustrated configuration of the chamber exit 32 that forms the chamber end 30 of the beamline 10, and enters a reaction chamber 310 filled with a reaction atmosphere 312. Within the reaction chamber 310, the laser beam 220 impinges on a source 314 for evaporation and / or sublimation of the material of the source 314, or on a substrate for heating the substrate. Note that the source 314 or the substrate is separated from the Bragg mirror 92 by a working distance 128.

[0103] In contrast, in the measurement mode (FIG. 8B), the Bragg mirror 92 is removed and the additional beamline element 14 is attached to the optical section 50 so that it extends substantially along the direction of the laser beam 220 that initially exits the upstream end 60 of the optical section 50. Alternatively, the additional beamline element 14 can be permanently attached to the optical section 50.

[0104] Within the beamline element 14, a detector 124 is disposed as the diagnostic means 120, specifically at a position within a measurement distance 126 away from the original position of the removed Bragg mirror 92. The detector 124 may be a camera, a beam monitor, a canvas, thermal paper, or the like. The measurement distance 126 is selected according to the working distance 128, and is preferably the same as the working distance 128. This ensures that the beam profile of the laser beam 220 at the detector 124 is substantially the same as the beam profile of the laser beam 220 at the source 314 or the substrate, although there may be small distortions due to the chamber window 36 and the Bragg mirror 92. In short, diagnostics of the laser beam 220 at the source 314 or the substrate can be performed without breaking the enclosure of the reaction chamber 310. [Explanation of symbols]

[0105] 10 Beamlines 12 Beam cavity 14 Beamline Elements 16 Joint 20 Source End 22 Laser entrance part 30 Chamber end 32 Chamber exit part 34 Bellows 36 Chamber window 40 Gas System 42 Purge gas 44 Entrance 46 Exit 50 Optical Section 52 Guidance Section 54 Case 56 section cavity 58 sides 60 Upstream end 62 First section opening 64 First connection interface 66 Downstream end 68 Second Section Opening 70 Second connection interface 72 Elastomer seal 74 Groove 76 screw holes 80 Optical Elements 82 Plane Mirror 84 Focus Mirror 86 Defocusing mirror 88 Axicon Mirror 90 Freeform mirror 92 Bragg Miller 94 Aperture 100 Adjustment screw 102 Adjustment Connector 110 Cooling means 120 Diagnostic Tools 122 Pyrometer 124 detectors 126 Measurement distance 128 working distance C center axis 200 Laser System 210 Laser Light Source 212 Support Structure 220 Laser Beam 300 Thermal Laser Evaporation System 310 Reaction Chamber 312 Reaction atmosphere 314 Source 316 Substrate

Claims

1. a beamline (10) for a laser beam (220) of a thermal laser evaporation (TLE) system (300), the beamline (10) extending between a source end (20) of the beamline (10) and a chamber end (30) of the beamline (10), such that the source end (20) is connectable to a laser light source (210) and the chamber end (30) is connectable to a reaction chamber (310) of the TLE system; The beamline (10) one or more optical sections (50) for modifying and / or controlling the properties of said laser beam (220); and / or - one or more straight guide sections (52) Two or more of the following are included: The optical section (50) and the guiding section (52) each have a housing (54) with an upstream end (60) having a first connection interface (64), a downstream end (66) having a second connection interface (70), and a section cavity (56) extending continuously within the housing (54) from a first section opening (62) at the upstream end (60) to a second section opening (68) at the downstream end (66); the one or more optical sections (50) and the one or more guiding sections (52) are arranged adjacently in pairs such that each section cavity (56) forms a continuous beam cavity (12) extending from the source end (20) to the chamber end (30); Each pair of adjacently arranged optical sections (50) and / or guidance sections (52) is arranged by connecting a first connection interface (64) of one section of the pair to a second connection interface (70) of the other section of the pair. Beamline (10).

2. 2. The beamline (10) of claim 1, The first connection interface (64) and the second connection interface (70) are adapted to each other to connect the respective section cavities (56) in an airtight and / or lighttight manner. Beamline (10).

3. 3. A beamline (10) according to claim 2, Both the first connection interface (64) and the second connection interface (70) have one or more placement spaces for accurately fitting alignment elements of the beamline (10) to align the pair of adjacently arranged optical sections (50) and / or guiding sections (52). Beamline (10).

4. 4. The beamline (10) of claim 3, the arrangement space surrounds each of the section openings (62, 68), and the alignment element is ring-shaped; and / or The arrangement space is a bore, and the alignment element is a screw or a bolt for fixing each of the adjacently arranged optical section (50) and / or guidance section (52) to each other. Beamline (10).

5. A beamline (10) according to any one of claims 2 to 4, the first connection interface (64) has an elastomeric seal (72) surrounding the first section opening (62) for providing an airtight and / or lighttight connection to each of the section cavities (56); and / or The second connection interface (70) has an elastomeric seal (72) surrounding the second section opening (68). Beamline (10).

6. A beamline (10) according to any one of claims 1 to 5, the one or more optical sections (50) having an optical element (80) disposed in each of the section cavities (56); The optical element (80) can modify and / or control one or more characteristics of a laser beam (220) incident on the section cavity (56) through the first section opening (62) such that the modified laser beam (220) exits the section cavity (56) through the second section opening (68). Beamline (10).

7. 7. A beamline (10) according to claim 6, The optical element (80) can modify and / or control the laser beam (220) such that the laser beam (220) entering the section cavity (56) substantially parallel to the central axis (C) of the first section opening (62) exits the section cavity (56) substantially parallel to the central axis (C) of the second section opening (68). Beamline (10).

8. 8. A beamline (10) according to claim 7, The central axis (C) of the first section opening (62) is perpendicular to the central axis (C) of the second section opening (68). Beamline (10).

9. A beamline (10) according to any one of claims 1 to 8, The section cavity (56) of the one or more induction sections (52) extends linearly from the first section opening (62) to the second section opening (68) along a common central axis (C) of the first section opening (62) and the second section opening (68). Beamline (10).

10. A beamline (10) according to any one of claims 1 to 9, the beamline (10) has a laser inlet (22), the laser inlet (22) forming the source end (20) and having a second connection interface (70) that is gas-tight and / or light-tight connectable to the laser source (210); and / or The beamline (10) has a chamber exit (32), which forms the chamber end (30) and has a first connection interface (64) and is connectable to the reaction chamber (310) in an airtight and / or lighttight manner. Beamline (10).

11. 11. A beamline (10) according to claim 10, the chamber exit (32) has a bellows (34); and / or The laser incident portion (22) has a bellows (34). Beamline (10).

12. 12. A beamline (10) according to claim 10 or 11, The chamber exit (32) has a chamber window (36) that can be positioned in a flange of the reaction chamber (310). Beamline (10).

13. A beamline (10) according to any one of claims 1 to 12, The beamline (10) includes a gas system (40) for creating a flow of purge gas (42) within the beam cavity (12). Beamline (10).

14. 14. A beamline (10) according to claim 13, comprising: One or more inlets (44) of the gas system (40) for injecting the purge gas (42) into the beam cavity (12) and one or more outlets (46) of the gas system (40) for exhausting the purge gas (42) from the beam cavity (12) are connected to the beam cavity (12) such that a flow of the purge gas (42) is supplied to substantially the entire beam cavity (12) between the source end (20) and the chamber end (30). Beamline (10).

15. A beamline (10) according to claims 10 and 14, The inlet (44) is connected to the laser incident portion (22), The outlet (46) is connected to the chamber outlet (32). Beamline (10).

16. A beamline (10) according to claims 10 and 14, The outlet (44) is connected to the laser incident portion (22), The inlet (44) is connected to the chamber outlet (32). Beamline (10).

17. A beamline (10) according to claims 10 and 14, one inlet (44) connected to the laser input (22), one inlet (44) connected to the chamber output (32), and one outlet (46) connected to the beam cavity between the source end (20) and the chamber end (30); or One outlet (46) is connected to the laser input (22), one outlet (46) is connected to the chamber output (32), and one inlet (44) is connected to the beam cavity between the source end (20) and the chamber end (30). Beamline (10).

18. 18. A beamline (10) according to any one of claims 13 to 17, comprising: Dry air or pure nitrogen is used as purge gas (42) Beamline (10).

19. 19. A beamline (10) according to any one of claims 1 to 18, comprising: the housing (54) of each of the one or more optical sections (50) and the one or more linear guidance sections (52) is mechanically rigid or at least essentially rigidifiable; The first connection interface (64) and the second connection interface (70) are adapted to each other to provide a mechanically rigid connection. Beamline (10).

20. 20. A beamline (10) according to any one of claims 1 to 19, comprising: The housing (54) of the one or more straight induction sections (52) is a tubular aluminum extrusion. Beamline (10).

21. 21. The beamline (10) of claim 20, A groove (74) is provided on the outer surface (58) of the housing (54) for fastening to a support structure (212). Beamline (10).

22. 22. A beamline (10) according to any one of claims 1 to 21, One or more screw holes (76) are provided in the first connection interface (64) and / or the second connection interface (70) of the housing (54). Beamline (10).

23. 23. The beamline (10) of claim 22, Two or more screw holes (76) are arranged in a rotationally symmetric pattern around each of the first section openings (62) and / or second section openings (68), in particular in a rotationally symmetric pattern of 180°, 120°, 90°, 72°, 60°, 45°, 40°, 30°, 20°, 10°, or 5° about the central axis (C) of each of the first section openings (62) and / or second section openings (68). Beamline (10).

24. 24. A beamline (10) according to claim 22 or 23, comprising: The first and second connection interfaces (64, 70) are arranged rotationally symmetrically, so that the beamline (10) has clamping means for securely fixing adjacently arranged optical and / or guiding section pairs. Beamline (10).

25. 25. A beamline (10) according to any one of claims 1 to 24, comprising: The surfaces (58) of the section cavities (56) are anodized to provide an oxide layer on the surfaces (58) of the section cavities (56). Beamline (10).

26. 26. A beamline (10) according to any one of claims 1 to 25, comprising: The one or more optical sections (50) are configured to detect the following characteristics of the laser beam (220): -direction; -size; -shape; -polarization; focal length; and -Intensity distribution Modify and / or control one or more of Beamline (10).

27. 27. The beamline (10) of claim 26, The optical element (80) of each of the one or more optical sections (50) comprises the following elements: - plane mirror (82); - focusing mirror (84); - defocusing mirror (86); - axicon mirror (88); - freeform mirror (90); -Brag Miller (92); - a diffraction mirror or a diffraction grating; and -Opening (94) having one or more of Beamline (10).

28. 28. A beamline (10) according to claim 26 or 27, comprising: The active part of the optical element (80) of each of the one or more optical sections (50) is machined from a monolithic block of metal, in particular copper. Beamline (10).

29. 29. A beamline (10) according to any one of claims 25 to 28, comprising: The optical elements (80) of the one or more optical sections (50) comprise actively adjustable mirrors. Beamline (10).

30. 30. The beamline (10) of claim 29, the spatial orientation of said actively adjustable mirror is adjustable by means of an adjustment screw (100), and / or The actively adjustable mirror has a reflective membrane on a cushion that can be filled with a conditioning fluid. Beamline (10).

31. 31. The beamline (10) of claim 30, The adjustment screws (100) and / or adjustment connectors (102) for adjustment fluids are accessible from outside the housing (54) of each of the optical sections (50). Beamline (10).

32. 32. The beamline (10) of any one of claims 1 to 31, The one or more optical sections (50) have cooling means (110) for actively cooling each of the optical elements (80). Beamline (10).

33. A beamline (10) according to claims 28 and 32, comprising: The cooling means (110) comprise cooling ducts for a coolant machined in and / or within a monolithic block of metal forming the active part of each of the optical elements (80). Beamline (10).

34. 34. The beamline (10) of any one of claims 1 to 33, The beamline (10) has beam diagnostic means (120) for measuring characteristics of the laser beam (220). Beamline (10).

35. 35. The beamline (10) of claim 34, The beam diagnostic means (120) comprises a pyrometer (122) for measuring the temperature of an optical element (80) of one of the one or more optical sections (50). Beamline (10).

36. 36. A beamline (10) according to claim 34 or 35, comprising: an optical element (80), in particular a Bragg mirror (92), of one of the one or more optical sections (50) that changes the direction of the laser beam (220) by 90° is removable, and an additional beam line element (14) is positioned and / or positionable at the position of the optical element (80) or along the original direction of the laser beam (220); The beam diagnostic means (120) comprises a detector (124) arranged at a measurement position of the additional beamline element (14). Beamline (10).

37. 37. The beamline (10) of claim 36, The one optical section (50) is the last optical section (50) before the chamber end (30), and a measurement distance (126) of the measurement position relative to the position of the removed optical element (80) is selected according to, and preferably equal to, a working distance (128) of the removed optical element (80) relative to a substrate (316) or source (314) in the reaction chamber (310). Beamline (10).

38. 38. A beamline (10) according to claim 36 or 37, comprising: The detector (124) is a camera and / or a beam monitor and / or a canvas and / or a thermal paper. Beamline (10).

39. 39. A beamline (10) according to any one of claims 1 to 38, comprising: The beamline (10) is a modular beamline (10) consisting of a plurality of optical sections (50) and / or guidance sections (52) as modules. Beamline (10).

40. 40. The beamline (10) of claim 39, a pair of optical sections (50) for redirecting and / or controlling the laser beam (220) are arranged together using the first and second connection interfaces (64 and 70), respectively, to form a junction (16) of the modular beamline (10); The modular beamline (10) is rotatable and / or pivotable at the joint (16) by rotating the optical sections (50) relative to one another. Beamline (10).

41. 41. The beamline (10) of claim 40, The optical section (50) Constructed according to claim 6 Beamline (10).

42. A laser system (200) for a thermal laser evaporation (TLE) system (300), comprising: a laser source (210) for providing a laser beam (220); a beamline (10) for directing the laser beam (220) from the laser source (210) to a reaction chamber (310) of the TLE system (300); Equipped with The beamline (10) is configured according to any one of claims 1 to 41 A laser system (200).

43. 43. The laser system (200) of claim 42, comprising: The laser system (200) includes a support structure (212); The laser light source (210) and the beam line (10) are disposed on the support structure (212). A laser system (200).

44. 44. The laser system (200) of claim 42 or 43, comprising: the laser light source (210) provides an infrared laser beam (220) having a wavelength between 0.1 μm and 1000 μm, preferably 10 μm; In particular, the laser light source (210) is CO 2 A laser light source (210) A laser system (200).

45. a reaction chamber (310) that can be filled with a reaction atmosphere (312); a substrate (316) disposed in the reaction chamber (310); one or more sources (314) disposed in the reaction chamber (310); a laser system (200) for providing a laser beam (220) for evaporating and / or sublimating material of the source (314) and / or for heating material of the substrate (316); Equipped with The laser system (200) is configured according to any one of claims 42 to 44. A thermal laser evaporation (TLE) system (300).

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