Beam line for laser beam, laser system and TLE system

Abstract

The present invention relates to a beam line (10) for a laser beam (220) of a thermal laser evaporation (TLE) system (300), the beam line (10) extending between a source end (20) of the beam line (10) and a chamber end (30) of the beam line (10), whereby the source end (20) is connectable with a laser source (210) and the chamber end (30) is connectable with a reaction chamber (310) of the thermal laser evaporation system (300), the beam line (10) comprising: one or more optical sections (50), one or more linear guide sections (52) for changing and / or controlling properties of the laser beam (220), and / or one or more linear guide sections (52); wherein each optical section (50) and guide section (52) respectively comprise a housing (54) having an upstream end (60) comprising a first connection interface (64), a downstream end (66) comprising a second connection interface (70), and a section cavity (56) extending continuously within the housing (54) from a first section opening (62) located in the upstream end (60) to a second section opening (68) located in the downstream end (66). Furthermore, the invention relates to a laser system (200) for a thermal laser vapor deposition system (300), comprising a laser source (210) for providing a laser beam (220) and a corresponding beam line (10). Furthermore, the invention relates to a thermal laser vapor deposition 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) arranged in the reaction chamber (310); and a corresponding laser system (200) for providing a laser beam (220) for evaporating and / or sublimating the material of the source (314) and / or heating the material of the substrate (316).

Description

Technical Field

[0001] The present invention relates to a beam line for a laser beam of a thermal laser evaporation (TLE) system, the beam line extending between a source end and a chamber end of the beam line, whereby the source end can be connected to a laser source and the chamber end can be connected to a reaction chamber of the TLE system, the beam line comprising:

[0002] one or more optical sections for changing and / or controlling the properties of the laser beam, and / or

[0003] one or more linear guiding sections;

[0004] wherein each optical section and guiding section respectively comprises a housing having: an upstream end including a first connection interface; a downstream end including a second connection interface; and a section cavity that continuously extends in the housing from a first section opening located in the upstream end to a second section opening located in the downstream end. Additionally, the present invention relates to a laser system for a thermal laser evaporation system, which comprises a laser source for providing a laser beam and a corresponding beam line according to the present invention. Furthermore, the present invention relates to a thermal laser evaporation system, which comprises: 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 corresponding laser system according to the present invention for providing a laser beam, the laser beam being used to evaporate and / or sublime the material of the source and / or heat the material of the substrate. Background Art

[0005] In thermal laser evaporation (TLE), source material is evaporated and / or sublimated by laser heating in a controlled environment (especially in a reaction chamber filled with a reaction atmosphere), usually with the aim of coating a substrate also disposed in the reaction chamber. Additionally, in many applications, heating the substrate is also advantageous, which can also be provided by a correspondingly adjusted laser irradiated onto the respective substrate.

[0006] In both cases, a laser beam suitable for the respective task must be provided. The laser beam is generated in a laser source, which is almost always disposed outside the reaction chamber. Therefore, the corresponding laser beam provided by the laser source must be guided into the reaction chamber to irradiate the source or the substrate respectively. However, for lasers with shorter wavelengths, especially lasers with a wavelength of approximately 1 μm, there are suitable optical fibers to conveniently route the laser from the source to the point of use, while for short-wavelength (ultraviolet light, UV) or long-wavelength laser sources, such as a CO2 laser with a wavelength of approximately 10 μm, which is particularly useful for substrate heating, there are no such optical fibers with appropriately low absorption.

[0007] In addition, for the intended use of the laser beam (the evaporation and / or sublimation of the source material and the heating of the substrate, respectively), the initial properties of the laser beam provided by the laser source itself may not be ideal. The properties of the laser beam may include, for example, direction, size, shape, focal length, spatial intensity distribution, and / or overall intensity. Therefore, in most applications, it is also necessary to change and / or control the properties of the laser beam between the laser source and its final destination within the reaction chamber.

[0008] For the optical setup of prior art laser beamlines, especially for laser beams with a long wavelength of about 10 μm, three functions need to be combined: the mechanical support of the optical components, a light-tight enclosure, and the filling of the beam path with an inert gas to prevent the possibility of absorption of the laser beam. Usually, the mechanical support is achieved through an optical bench that does not provide an enclosure, while the enclosure must cover the complete setup on the optical bench to accommodate the beam and the purge gas, but does not provide mechanical support for the optical components. In particular, for the intended use of the laser beam in a thermal laser evaporation system, this optical-bench-based solution is not suitable. SUMMARY OF THE INVENTION

[0009] 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 prior art. Specifically, 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 provide a simple and unified structure for guiding the laser beam provided by a laser source to the reaction chamber of a thermal laser evaporation system, which structure in particular provides mechanical support for the necessary tools for changing and / or controlling the properties of the laser beam and at the same time encloses the laser beam in its path through the beamline, preferably also providing accommodation for the purge gas.

[0010] This object is achieved by the corresponding independent patent claims. Specifically, this object is achieved by a beamline for a laser beam according to claim 1, a laser system according to claim 42, and a thermal laser evaporation system according to claim 45. The dependent claims describe preferred embodiments of the present invention. In terms of technical significance, the details and advantages described with respect to the beamline according to the first aspect of the present invention also relate to the laser source according to the second aspect of the present invention and the thermal laser evaporation system according to the third aspect of the present invention, and vice versa.

[0011] According to a first aspect of the present invention, this object is achieved by a beamline of a laser beam for a thermal laser evaporation (TLE) system, the beamline extending between a source end of the beamline and a chamber end of the beamline, whereby the source end can be connected to a laser source and the chamber end can be connected to a reaction chamber of the thermal laser evaporation system.

[0012] The beamline comprises two or more of the following:

[0013] One or more optical sections for changing and / or controlling the properties of the laser beam, and / or one or more linear guiding sections;

[0014] Wherein each optical section and guiding section respectively comprises a housing having an upstream end including a first connection interface, a downstream end including a second connection interface, and a section cavity that continuously extends in the housing from a first section opening located in the upstream end to a second section opening located in the downstream end, wherein one or more optical sections and one or more guiding sections are arranged adjacent to each other in pairs such that the corresponding section cavities form a continuous beam cavity extending from the source end to the chamber end, and wherein each section pair of adjacent arranged optical sections and / or guiding sections is arranged by connecting the first connection interface of one section of the section pair to the second connection interface of the other section of the section pair.

[0015] The beamline according to the present invention is intended to be used as part of a thermal laser evaporation system. The thermal laser evaporation system generally comprises at least a reaction chamber, in which a source of a material to be evaporated and / or sublimated and a substrate to be coated with the source material to be evaporated and / or sublimated are arranged. A laser source provides a laser beam, which is used for the evaporation and / or sublimation, or for heating the substrate to improve the coating process.

[0016] Safely guiding the laser beam from the laser source to the reaction chamber is crucial for the function of the thermal laser evaporation system. For this purpose, the beamline according to the present invention is constructed such that it extends from the laser source to the reaction chamber. The source end of the beamline that can be connected to the laser source and the chamber end that can be connected to the reaction chamber ensure that the corresponding connections with the laser source and the reaction chamber can be established. In addition to the beamline according to the present invention, no other guiding tools are required to guide the laser beam provided by the laser source to the reaction chamber of the thermal laser evaporation system.

[0017] The beamline according to the present invention consists of two or more sections, wherein these sections can be provided in two different forms, namely, optical sections and linear guiding sections. In other words, the sections of the beamline according to the present invention can consist of two optical sections, or two guiding sections, or any combination of one or more optical sections and one or more guiding sections.

[0018] These optical sections are configured such that each optical section can vary and / or control one or more properties of the laser beam. For example, the average direction of the laser beam can be varied and / or controlled by simply reflecting the laser beam off a mirror inclined in the direction of the irradiated laser beam, or the shape of the laser beam can be varied and / or controlled by cutting portions of the laser beam (e.g., through a hole of a corresponding shape). These guiding sections serve as a closed path for the laser beam to shield (protect) the laser beam from the environment.

[0019] Both types of sections share a construction with a housing, where the housing includes a section cavity extending between a first section end in the upstream end of the housing and a second section end in the downstream end of the housing. The section cavity is for the path of the laser beam. For this purpose, the dimensions of the cross-section of the section cavity perpendicular to the direction of the laser beam are selected such that the laser beam can propagate within the section cavity without hitting the inner surface of the section cavity. Thus, during operation of the thermal laser evaporation system, the laser beam enters the section cavity of the corresponding optical section or guiding section through a first section opening, travels through the section cavity within the corresponding section, and exits the corresponding section again through a second section opening.

[0020] The corresponding housings of these sections can be made of metal (e.g., aluminum). For example, the manufacture of these sections can include machining the housing from a solid piece of metal. Although the guiding section has a simple linear structure, where the section cavity travels straight and linearly from the first section opening to the second section opening, the shape of the section cavity of the optical section can be different, for example, including two straight sections connected to each other. This allows for a specific variation and / or control of the direction of the laser beam.

[0021] In the optical section, suitable tools are arranged within the corresponding section cavity to allow for the variation and / or control of the properties of the laser beam. In other words, the optical section provides the necessary mechanical support for the corresponding tools within its section cavity. In contrast, the section cavity of the guiding section is empty and does not have such tools.

[0022] According to the present invention, the housings of the optical section and the guiding section are also configured such that they have a first connection interface at their respective upstream ends and a second connection interface at their respective downstream ends. These connection interfaces are in turn configured corresponding to each other such that each first connection interface can be connected to any second connection interface. In other words, any pair of optical sections and guiding sections can be attached to each other in any order, i.e., optical-optical, optical-guiding, guiding-optical, and guiding-guiding, respectively.

[0023] Thus, in any pair of optical sections and guiding sections, the corresponding sections can be arranged adjacent to each other. 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 the first pair of sections can also be the upstream section of the subsequent second pair of sections. Thus, the beamline according to the present invention can include a plurality of sections arranged one above the other subsequently. Thus, any long distance between the laser source and the reaction chamber can be bridged by the beamline according to the present invention. However, if sufficient, the beamline may also consist of a single pair of sections.

[0024] Specifically, by combining multiple sets of two or more sections, whether they are optical sections, guiding sections, or both, the corresponding section cavities are connected to each other to form a continuous beam cavity that starts at a first opening in the upstream end of the corresponding first section of the multiple combined sections and terminates at a second opening in the downstream end of the corresponding last section of the multiple combined sections. Thus, the beam cavity extends continuously from the source end of the formed beamline to the chamber end. In other words, the beamline according to the present invention provides an enclosure for the laser beam that starts at the source end and thus at the laser source and extends to the chamber end and thus to the reaction chamber. Since the beam cavity extends continuously, it can also be used to accommodate purge gas.

[0025] In summary, the beamline according to the present invention is a simple and unified structure for guiding the laser beam provided by the laser source to the reaction chamber of a thermal laser evaporation system. It provides mechanical support to the necessary tools in its optical sections for changing and / or controlling the properties of the laser beam, while enclosing the laser beam in its path through the beamline. In addition, if appropriate, accommodation for purge gas can also be provided.

[0026] In addition, the beamline according to the present invention can include: a first connection interface and a second connection interface that are adapted to each other to provide an airtight and / or lighttight connection of the corresponding section cavities. Preferably, the connection provided by the corresponding section cavities is both airtight and lighttight. In the sense of the present invention, being both airtight and lighttight will be understood as providing the corresponding sealing with respect to the environment. The connection between the corresponding sections is a weak point along the beamline in terms of sealing (the corresponding airtightness and lighttightness) because the corresponding section cavities themselves can easily provide airtight and / or lighttightness respectively. However, by providing a first connection interface and a second connection interface that are adapted to each other, an airtight and / or lighttight connection between two adjacent sections can also be ensured. The corresponding adaptation of the connection interfaces can be, for example, a tongue and groove part in the corresponding connection interfaces, or a dedicated sealing tool. In addition, the precise machining of the connection interfaces supports the adaptation.

[0027] As an enhancement of the beamline according to the present invention, both the first connection interface and the second connection interface may include one or more corresponding arrangement spaces for precisely assembling alignment elements of the beamline, thereby aligning pairs of adjacent optical sections and / or guiding sections. In other words, by precisely assembling the alignment elements in the corresponding arrangement spaces of each connection interface, the relative positioning of the correspondingly adjacent optical sections and / or guiding sections can be provided in a very precise manner. Thereby, precise alignment of the two elements of the section pair can be provided, wherein the precise alignment correspondingly and automatically improves the airtightness and lighttightness of the connection.

[0028] In another improved embodiment of the beamline according to the present invention, the arrangement space surrounds the corresponding section opening, and the alignment element is annular, and / or wherein the arrangement space is a hole and the alignment element is a screw or bolt for fixing the corresponding section pairs of the adjacent optical sections and / or guiding sections to each other. This list is not complete and can be extended by further embodiments of the arrangement space and the correspondingly shaped alignment elements, which are precisely assembled in the corresponding arrangement spaces in the first connection interface and the second connection interface respectively.

[0029] Furthermore, the beamline according to the present invention can be improved in the following way: in order to provide an airtight and / or lighttight connection of the corresponding section cavities, the first connection interface includes an elastomeric seal surrounding the first section opening, and / or the second connection interface includes an elastomeric seal surrounding the second section opening. As mentioned above, dedicated sealing tools can be used to provide an airtight and / or lighttight connection. Elastomeric seals (such as O-rings) are a suitable choice for such sealing tools. By surrounding the corresponding opening at the end of the section, reliable sealing of the corresponding opening can be provided. The elastomeric seals can be provided in one or both connection interfaces, for example with different radii. Additionally, they can be supported by corresponding grooves in the connection interfaces (in the connection interface with the elastomeric seal and / or in the complementary connection interface).

[0030] The beamline according to the present invention may also be characterized in that one or more optical sections include optical elements arranged in the corresponding section cavities, wherein the optical elements are capable of changing and / or controlling one or more properties of the laser beam entering the section cavity through the first section opening, such that the changed laser beam exits the section cavity through the second section opening. In other words, in the section cavity of the corresponding optical section, suitable tools for providing mechanical support for the corresponding optical elements are provided. By ensuring that the laser beam (whose properties are changed and / or controlled by the optical tools) exits the section cavity through the second opening again, interruption of the laser beam by the corresponding optical section can be avoided.

[0031] For example, the optical element can be a planar mirror, and the property of the laser beam that is changed can be the direction of the laser beam, which is changed by simple reflection on the mirror. Thus, corner pieces of the beamline can be easily provided, especially without the risk of blocking the laser beam.

[0032] According to another improvement, the beamline according to the invention can comprise: an optical element capable of changing and / or controlling the laser beam such that a laser beam entering the section cavity substantially parallel to the central axis of the opening of the first section exits the section cavity substantially parallel to the central axis of the opening of the second section. In other words, since the guiding section does not change the alignment of the laser beam, by providing appropriately configured optical elements for all the optical sections, a laser beam entering the beamline according to the invention at the source end parallel to the central axis remains parallel to the central axis actually present in the corresponding part of the beamline throughout the beamline, and also exits the beamline at the chamber end parallel to the central axis of the last section cavity of the last section of the beamline.

[0033] Furthermore, the guiding sections between the respective optical sections of the beamline can have any length since they do not affect the parallel alignment of the laser beam with respect to the corresponding central axis. This provides great flexibility when routing the beamline from the laser source to the reaction chamber. Specifically, the geometry of the entire beamline can be changed and reconfigured without affecting the shape of the laser beam or the performance and final intensity distribution of the beamline. The optical path remains unaffected. This is especially true for rotationally symmetric laser beams.

[0034] Furthermore, the beamline according to the invention can be improved by making the central axis of the opening of the first section perpendicular to the central axis of the opening of the second section. Thus, the direction of the laser beam can be changed by 90° by the respective optical sections. Since the second opening in the downstream end of the respective optical section of the laser beam remains parallel to the central axis, all other properties of the laser beam (such as shape, spatial intensity distribution, and / or focal length) can remain unaffected. However, if the optical element has the corresponding function and / or there are more optical elements present in the respective section cavity of the optical element, other properties of the laser beam may also be changed and / or controlled in addition to the changed direction.

[0035] In another embodiment, the beamline according to the invention can comprise: the section cavities of one or more guiding sections linearly extend from the opening of the first section to the opening of the second section along the common central axis of the opening of the first section and the opening of the second section. In other words, the section cavity has a tubular shape limited by the section openings, the section openings are parallel to each other, and in addition, they share a common central axis. Preferably, the common central axis also forms the central axis of the tubular section cavity. By this construction method, it can be easily ensured that the respective guiding sections do not affect the parallel alignment of the laser beam with respect to the corresponding central axis.

[0036] In addition, the beamline according to the present invention may be characterized in that the beamline includes a laser inlet section, wherein the laser inlet section forms a source end, includes a second connection interface, and can be connected to the laser source in an airtight and / or lighttight manner, and / or wherein the beamline includes a chamber outlet section, wherein the chamber outlet section forms a chamber end, includes a first connection interface, and can be connected to the reaction chamber in an airtight and / or lighttight manner. By providing the laser inlet section, it can be ensured that for the source end of the beamline, an airtight and / or lighttight connection to the laser source and a connection to the first connection interface at the upstream end of the first section of the beamline can be established respectively. Similarly, by providing the chamber outlet section, it can be ensured that for the chamber end of the beamline, an airtight and / or lighttight connection to the reaction chamber and a connection to the second connection interface at the downstream end of the last section of the beamline can be established respectively. Thereby, airtight and / or lighttight connections can be provided at both ends of the beamline. In other words, the beamline according to the present invention can be configured to provide a connection between the laser source and the reaction chamber, and the connection is airtight and lighttight with respect to the environment.

[0037] Furthermore, the beamline according to the present invention can be improved in the following way: the chamber outlet section includes a bellows, and / or the laser inlet section includes a bellows. The bellows is an elastic element with a cavity, which (as part of the chamber outlet section and / or the laser inlet section) shields the area between the last optical section or guiding section of the beamline and the reaction chamber and / or between the first optical section or guiding section of the beamline and the laser system to prevent laser and / or gas leakage in this area, while mechanically disconnecting the beamline from the reaction chamber and / or the laser system. Thereby, decoupling vibrations can be provided and other problems can be avoided, such as mechanical stress caused by thermal expansion between the beamline and the reaction chamber and / or the laser system.

[0038] In another improved embodiment of the beamline according to the present invention, the chamber outlet section includes a chamber window, which can be arranged at the flange of the reaction chamber. Thus, the beamline ends with the chamber window. Since the chamber window can be arranged at the flange of the reaction chamber, no additional fixing tools and sealing tools are required to arrange the chamber outlet section of the beamline according to the present invention at the reaction chamber of the thermal laser evaporation system, especially on the chamber window of the reaction chamber. The chamber outlet section and its chamber window already include all the tools for sealing the reaction chamber of the thermal laser evaporation system, such as elastomeric seals (such as O-rings), and / or circular sharp edges for forming a knife-edge seal. Thereby, the setup of the thermal laser evaporation system can be simplified.

[0039] Furthermore, the beamline according to the present invention may be characterized in that the beamline includes a gas system for providing a purge gas flow in the beam cavity. For some laser beams, absorption in the atmosphere present along their path through the beamline may be a problem. For example, water vapor causes strong absorption of infrared laser beams (especially infrared laser beams with a wavelength of approximately 10 μm). The gas system, which is part of the beamline according to the present invention, can be used to solve this problem because the gas system can provide a purge gas flow in the beam cavity of the beamline. Preferably, the purge gas can be selected relative to the wavelength of the laser beam to be guided in the beamline to minimize the risk of absorption of the laser beam along its path from the source end to the chamber end of the beamline.

[0040] Furthermore, the beamline can 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 extracting the purge gas from the beam cavity to the beam cavity to provide a purge gas flow throughout the beam cavity between the source end and the chamber end. The source end and the chamber end respectively mark the start and the end of the beam cavity. At least one inlet of the corresponding arrangement of the gas system and at least one outlet of the same corresponding arrangement of the gas system provide a purge gas flow through the complete beam cavity. The flow direction of the purge gas is not determined and can be selected as needed.

[0041] According to a first alternative improvement, the beamline according to the present invention may include an inlet connected to the laser inlet section and an outlet connected to the chamber outlet section. If present, along the propagation of the laser beam, the laser inlet section forms the first element of the source end and the chamber outlet section forms the last element of the chamber end. Thus, by providing an inlet of the gas system at the laser inlet section and an outlet of the gas system at the chamber outlet section, it is ensured that the purge gas flow through the complete beam cavity can be further improved.

[0042] According to a second alternative improvement, the beamline according to the present invention may include an outlet connected to the laser inlet section and an inlet connected to the chamber outlet section. Similarly, if present, along the propagation of the laser beam, the laser inlet section forms the first element of the source end and the chamber outlet section forms the last element of the chamber end. Thus, also by providing an outlet of the gas system at the laser inlet section and an inlet of the gas system at the chamber outlet section, it is ensured that the purge gas flow through the complete beam cavity can be further improved.

[0043] According to a third alternative improvement, the beamline according to the present invention may include: an inlet connected to the laser inlet section, and an inlet connected to the chamber outlet section, and an outlet connected to the beam cavity located between the source end and the chamber end; or, an outlet connected to the laser inlet section, and an outlet connected to the chamber outlet section, and an inlet connected to the beam cavity located between the source end and the chamber end. Similarly, if present, along the propagation of the laser beam, the laser inlet section forms the first element of the source end, and the chamber outlet section forms the last element of the chamber end. Therefore, it is also ensured that the purge gas flow through the complete beam cavity can be further improved by providing an inlet respectively located in the laser inlet section and the chamber outlet section, and by providing an outlet connected to the beam cavity somewhere between the two, or vice versa.

[0044] In addition, the beamline according to the present invention can also be improved by using dry air or pure nitrogen as the purge gas. Dry air and pure nitrogen are purge gases substantially free of water vapor. Therefore, especially for infrared laser beams, particularly infrared laser beams with a wavelength of about 10 μm, dry air and pure nitrogen are suitable purge gases for preventing the absorption of the laser beam within the beamline according to the present invention.

[0045] In yet another embodiment, the beamline according to the present invention may be characterized in that the respective housings of one or more optical sections and one or more linear guiding sections are mechanically rigid or at least essentially hardenable, and wherein the first connection interface and the second connection interface are adapted to each other to provide a mechanically rigid connection. In other words, in each section (i.e., respectively in the optical section and the guiding section), the spatial orientation and position of the upstream and downstream ends are fixed or can be fixed relative to each other, and do not change under mechanical stress. In addition, since the connection of the respective first connection interface and the second connection interface is also mechanically rigid, such fixation of the relative spatial positioning and orientation can also be achieved for the source end and the chamber end of the beamline. In other words, the beamline according to the present invention can be arranged in a self-supporting manner.

[0046] Furthermore, the beamline may include: the housing of one or more linear guiding sections is a tubular extruded aluminum section. The tubular extruded section can provide the advantage of high rigidity due to its tubular shape, especially with respect to the torque around its longitudinal axis. The ribs along the axis and around the circumference of the tubular shape can further enhance the rigidity. In addition, using aluminum as the material makes the section light in weight and has excellent thermal conductivity, thus preventing local bending caused by local thermal expansion.

[0047] Additionally, the beamline according to the present invention can be improved by providing grooves on the outer surface of the housing for fixing to a support structure. As described above, the beamline according to the present invention can be provided in a self-supporting manner as a whole. However, for example, in order to ensure a fixed relative positioning and / or orientation of the complete beamline relative to the laser source and / or the reaction chamber, and / or if the beamline itself has to be supported to prevent its overall tipping over, it may be advantageous to provide an overall support for the beamline. By providing grooves on the outer surface of the housing (especially an extruded tubular aluminum section), fixation on any additionally provided external support can be easily achieved.

[0048] In another embodiment, the beamline according to the present invention can include providing one or more threaded holes in the first connection interface and / or the second connection interface of the housing. The threaded holes can be provided correspondingly in the housings of both the optical section and the guiding section. In such threaded holes, corresponding screws can be inserted and fixed, especially for providing a connection of the first connection interface on top of the second connection interface. In particular, the screws located in the threaded holes are a simple and firm way to provide a mechanically rigid connection between the corresponding first connection interface and the corresponding second connection interface.

[0049] The beamline according to the present invention can be further improved in that two or more threaded holes are arranged in a rotational symmetric pattern, especially a rotational symmetric pattern of 180°, 120°, 90°, 72°, 60°, 45°, 40°, 30°, 20°, 10° or 5°, around the central axis of the corresponding first section opening and / or the second section opening. Thereby, the number of threaded holes defines the rotational symmetric pattern and vice versa. In other words, any pair of sections sharing this positioning of the threaded holes can be arranged on top of each other in several specific different orientations (correspondingly defined by the rotational symmetric pattern of this embodiment). Especially for a rotationally symmetric laser beam, any such rotation does not affect the shape of the beam at the sample position or at other positions along the beamline. Thus, the beamline can be "folded" in many different ways depending on the laboratory or plant space, the placement of the laser source, the size and position of the reaction chamber, etc.

[0050] Alternatively or additionally, the beamline according to the present invention may include a first connection interface and a second connection interface that are rotationally symmetrically arranged, and thus, the beamline includes a clamping tool for firmly fixing a pair of adjacent sections of an optical section and / or a guiding section. In this embodiment, the two sections (an optical pair or a guiding pair or a hybrid pair) include rotationally symmetric connection interfaces. By fixing these sections together with the clamping tool, any relative rotation between these sections can be provided. Thus, all the advantages described in the previous section can also be provided by the embodiment described in this section, but additionally, the two sections can even rotate freely relative to each other. Thus, the degree of freedom in setting up the beamline according to the present invention can be further improved.

[0051] Additionally, the beamline according to the present invention may be characterized in that the surface of the section cavity is anodized to provide an oxide layer on the surface of the section cavity. Anodizing the surface of the section cavity (especially if the corresponding optical section or guiding section is made of aluminum) ensures a relatively thick oxide layer on the surface. Combined with the low divergence of the laser beam along the optical path and thus the low incident angle on the wall, this results in good absorption of stray radiation in the surface of the corresponding section cavity, thereby reducing the stray radiation at the position of the source or the substrate in the reaction chamber. Specifically, laser radiation with a wavelength of about 10 μm (which is most favorable for heating substrates of most materials) is effectively absorbed by aluminum oxide.

[0052] According to another embodiment, the beamline may include one or more optical sections for changing and / or controlling one or more of the following properties of the laser beam:

[0053] Direction;

[0054] Size;

[0055] Shape;

[0056] Polarization;

[0057] Focal length; and

[0058] Intensity distribution.

[0059] This list is not complete and can be extended with other properties of the laser beam. By changing and / or controlling one or more of the properties of the laser beam located within the beamline, a laser beam with selected and controlled properties suitable for the evaporation and / or sublimation of the source material and / or the heating of the substrate material can be provided in the reaction chamber.

[0060] For improvement, the beamline may further be characterized in that the corresponding optical elements of one or more optical sections include one or more of the following elements:

[0061] Plane mirrors;

[0062] Focusing mirror;

[0063] Defocusing mirror;

[0064] Conical mirror;

[0065] Free-form mirror;

[0066] Bragg mirror;

[0067] Diffractive mirror or grating; and

[0068] Aperture.

[0069] This list is not complete and can be extended by other optical elements for changing and / or controlling the properties of the laser beam. In particular, the above list includes mirrors for changing and / or controlling properties, which are most suitable for use with infrared laser beams, which are commonly used in thermal laser evaporation systems. However, if suitable for practical use, especially the laser beam used, most of the optical elements listed above as mirrors can also be constructed as transmissive elements, such as lenses.

[0070] Furthermore, the beam line can be further improved in that the active part of the corresponding optical elements of one or more optical sections is machined from a solid piece of metal, especially copper. Metals, especially copper, can be machined with extremely high precision, where such machined surfaces also include a high reflectivity for most of the laser beams commonly used in thermal laser evaporation systems. Another example of a suitable metal is aluminum. Thus, machining the active part of the optical element from a solid piece of metal provides optical elements with high precision and high reflectivity.

[0071] According to another improved embodiment of the beam line of the present invention, the optical elements of one or more optical sections include actively adjustable mirrors. "Actively adjustable" in the sense of the present invention means that the spatial orientation and / or spatial shape of the mirror can be actively changed, especially during the operation of the laser source. Thus, the corresponding properties changed and / or controlled by the corresponding optical elements can be actively adjusted during the operation of the thermal laser evaporation system.

[0072] In addition, the beamline according to the present invention can also be improved in the following ways: The spatial orientation of the actively adjustable mirror can be adjusted by adjusting screws, and / or wherein the actively adjustable mirror includes a reflective film located on a cushion that can be filled with an adjustable fluid. Adjusting screws (especially three adjusting screws) are a simple and reliable way to adjust the spatial orientation of the adjustable mirror. In addition, the spatial shape of the reflective film located on the cushion strongly depends on the filling amount in the cushion. Therefore, adjusting the filling of the cushion is also a simple and reliable way to adjust the spatial shape of the adjustable mirror.

[0073] According to an additional improvement, the beamline according to the present invention can include: The adjusting screws and / or the adjusting connectors for the adjusting fluid can be used from the outside of the housing of the corresponding optical section. In both cases, active adjustment of the corresponding orientation or shape of the adjustable mirror can be provided without directly using the active components of the adjustable mirror itself. In other words, without opening the corresponding optical section of the beamline. Therefore, it can be very easily ensured that the corresponding optical elements can be actively adjusted during the operation of the thermal laser evaporation system.

[0074] Furthermore, the beamline can also be characterized in that: One or more optical sections include cooling means to actively cool the corresponding optical elements. Metal mirrors, which are preferably used as optical elements in the beamline according to the present invention, have high reflectivity. However, they absorb a small portion of the irradiated laser. Actively cooling the mirrors compensates for the energy deposition caused by the absorption of the irradiated laser and thus maintains the expected optical properties of the corresponding optical elements.

[0075] In addition, the hole is also an optical element in the sense of the present invention. The hole (which can also be machined from a metal block) is in contrast to a mirror that is used to deliberately block a part of the laser beam. A large amount of laser energy deposition in the block of the hole is usually inevitable. Especially for the hole, active cooling is beneficial to maintaining the properties of the hole, such as preventing shape changes caused by thermal stress.

[0076] In a specifically improved embodiment, the beamline can include: Cooling means, which includes cooling pipes for a coolant, and which are machined in and / or machined to form the active part of the corresponding optical element from a single piece of metal. As described above, machining the active part of the optical element from a single piece of metal gives the optical element high precision. In addition, metals (especially copper and aluminum) are highly thermally conductive. By arranging cooling pipes in the block of the single piece of metal, the thermal energy deposited by the irradiated laser beam can be removed in a very effective way.

[0077] In addition, the beamline may be characterized in that it includes beam diagnostic tools for measuring the properties of the laser beam. The main purpose of the beamline according to the present invention is to provide a laser beam reaching the reaction chamber and thus having specific selected properties within the reaction chamber. In most cases, a thermal laser evaporation system includes diagnostic tools for measuring properties. As described above, the beamline according to the present invention may include an optical section having optical elements that are adjustable, particularly actively adjustable. Thus, for example, in order to directly feedback the adjustment applied to the adjustable optical element, it may be advantageous to directly measure one or more properties of the laser beam within the beamline (and thus before the laser beam enters the reaction chamber). The beam diagnostic tools provided by the beamline itself may provide such measurements.

[0078] In a possible embodiment of the beamline according to the present invention, the beam diagnostic tool includes a pyrometer for measuring the temperature of an optical element of one of the optical sections. By measuring the temperature of the optical element, the deposition of the energy absorbed from the irradiated laser beam can be measured. Thus, the intensity of the irradiated laser beam can be calculated. Preferably, the pyrometer provides a temperature measurement with spatial resolution to allow the calculation of the spatially resolved intensity distribution of the irradiated laser beam.

[0079] Additionally or alternatively, the pyrometer can also be used to measure the temperature of the substrate or source heated by the laser beam. For this purpose, preferably, the pyrometer is arranged such that it sees the substrate or source along the beam axis of the laser beam, which can be achieved by arranging a Bragg mirror or a semi-transparent optical element (such as a beamsplitter or a semi-transparent mirror) in the path of the laser beam and correspondingly arranging a respective pyrometer on the back side of the Bragg mirror or the semi-transparent optical element.

[0080] Furthermore, the Bragg mirror includes the characteristic of being reflective only for a specific and particularly narrow wavelength band. The laser outside the said band is transmitted through the Bragg mirror and can thus be directly measured by the pyrometer. In this case, even a direct measurement of the substrate temperature can be provided by the pyrometer, at least for the part of the laser beam transmitted through the Bragg mirror.

[0081] Furthermore, the beamline can be further improved in the following way: the optical element (especially the Bragg mirror) of one of the optical sections that changes the direction of the laser beam by 90° can be removed, and additional beamline elements are arranged and / or can be arranged at the position of the optical element or along the initial direction of the laser beam, wherein the beam diagnostic tool includes a detector arranged at the measurement position in the additional beamline elements. By removing the optical element, the laser beam is no longer reflected and propagates directly into the additional beamline elements, and can be studied by a detector arranged therein for this purpose. Preferably, the detector can be directly arranged in the path of the laser beam. Thereby, a direct measurement of the properties of the laser beam can be provided.

[0082] Furthermore, the beamline according to the present invention can also include that one of the optical sections is the last optical section before the chamber end, and the measurement distance from the measurement position to the position of the removed optical element is selected according to the working distance of the removed optical element to the substrate or source in the reaction chamber, preferably equal to the working distance. The working distance is the distance between the optical element of the last optical section and the destination (i.e., the source or substrate) of the laser beam located in the reaction chamber. Especially for a laser beam aligned parallel to the central axis of the beamline (at least parallel to the central axis of the first opening of one of the optical sections), this results in a direct correlation between the properties of the laser beam at the measurement position and the properties of the laser beam that would appear at the working distance. In the case where the measurement distance is equal to the working distance, the properties are even substantially the same, with the only difference being small deformations caused by the chamber window. Thereby, a measurement of the properties of the laser beam at its destination in the reaction chamber can be provided without opening the reaction chamber.

[0083] The beamline according to the present invention can be further improved in the following way: the detector is a camera and / or a beam monitor and / or a canvas and / or thermal paper. This list is not complete and can be extended by other suitable detectors. All the listed detectors can be used to study the spatially resolved image of the intensity distribution of the laser beam.

[0084] In another embodiment of the beamline according to the present invention, the beamline is a modular beamline, which includes a plurality of optical sections and / or guiding sections as modules. In particular, since all sections (i.e., the corresponding optical sections and guiding sections) share the same first connection interface and second connection interface, all sections can be arranged in any order. In addition, it is possible to add and / or remove one or more sections to change the settings of the beamline according to the present invention without any problems. Thereby, a plurality of possible embodiments of the beamline according to the present invention can be provided.

[0085] Furthermore, the beamline according to the present invention can be further improved in the following way: A pair of optical sections that change and / or control the direction of the laser beam are arranged on top of each other by using their respective first connection interfaces and second connection interfaces to form a joint of the modular beamline, wherein the modular beamline can be rotated and / or pivoted at the joint by rotating the optical sections relative to each other. Since both of the optical sections forming the joint of the modular beamline are capable of changing and / or controlling the direction of the laser beam, rotating the optical sections relative to each other provides the possibility of arbitrarily changing the initial direction of the laser beam at the opening of the first section of the corresponding upstream optical element of the joint to the final direction of the laser beam at the opening of the second section of the corresponding downstream optical element of the joint. Depending on the respective changes in the direction of the laser beam provided by each of the two optical sections, multiple possible changes in the direction of the laser beam can be provided by the joint of the modular beamline constructed as described in this paragraph.

[0086] According to a further improvement of the embodiment of the beamline according to the present invention described above, the optical sections are constructed according to claim 6 of the present invention. This particularly includes that the two optical sections forming the joint each include optical elements arranged in corresponding section cavities, wherein the optical elements are capable of changing and / or controlling the direction of the laser beam such that the laser beam entering the corresponding section cavity parallel to the central axis of the opening of the first section exits the section cavity parallel to the central axis of the opening of the second section, and wherein, in the two optical sections, the central axis of the opening of the first section is perpendicular to the central axis of the opening of the second section. In other words, each of the two optical sections forming the joint changes the direction of the laser beam by 90°.

[0087] In addition, the laser beam enters the joint substantially parallel to the central axis of the opening of the first section of the first optical section of the joint and also exits the joint substantially parallel to the central axis of the opening of the second section of the second optical section of the joint. In particular, the latter is independent of the relative rotational position of the two optical sections forming the joint and the relative rotational orientation of the corresponding optical section with respect to the next guiding section or optical section adjacent to the modular beamline. Therefore, a change in the initial direction of the laser beam to a final direction substantially covering each solid angle can be provided, especially without changing the optical path of the beamline, but only limited by the size of the optical section perpendicular to the corresponding direction of the laser beam.

[0088] According to a second aspect of the present invention, this object is achieved by a laser system for a thermal laser evaporation (TLE) system, the laser system comprising a laser source and a beam line, the laser source being adapted to provide a laser beam, and the beam line being adapted to guide the laser beam from the laser source to a reaction chamber of the thermal laser evaporation system. The laser system according to the present invention is characterized in that the beam line is constructed according to the first aspect of the present invention. Specifically, the beam line is arranged at the laser source with its source end, and the laser beam provided by the laser source enters the beam line through the source end of the beam line and is guided within the beam line to its chamber end, which in turn may be arranged and connected to the reaction chamber of the thermal laser evaporation 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 beam line according to the first aspect of the present invention.

[0089] Furthermore, the laser system according to the present invention may be further characterized in that the laser system comprises a support structure, and wherein the laser source and the beam line are arranged at the support structure. By providing a common support structure for the laser source and the beam line, the relative positioning of the components of the laser system can be fixed. In particular, such fixation does not have to be ensured by arranging the source end of the laser beam at and / or on the laser source. Additionally, even if the beam line is provided as a self-supporting structure, arranging the beam line on an external support prevents its overall tipping over.

[0090] In addition, the laser system according to the present invention may comprise: the laser source provides an infrared laser beam having a wavelength between 0.1 μm and 1000 μm (preferably 10 μm), in particular wherein the laser source is a CO2 laser source. Infrared lasers are typically used in thermal laser evaporation systems because they can be provided at high intensities, especially for continuous operation. On the other hand, UV lasers are suitable for the evaporation and / or sublimation of various source materials. Therefore, by using a laser source that provides a laser beam in the ultraviolet (UV) or infrared (IR) region, it may be more suitable to use the laser system according to the present invention in a thermal laser evaporation system.

[0091] According to a third aspect of the present invention, this object is achieved by a thermal laser evaporation (TLE) system, the thermal laser evaporation system comprising: a reaction chamber that can be filled with a reaction atmosphere; a substrate arranged in the reaction chamber; one or more sources arranged in the reaction chamber; and a laser system that is adapted to provide a laser beam for evaporating and / or sublimating the material of the source and / or heating the material of the substrate. The thermal laser evaporation system according to the present invention is characterized in that the laser system is constructed according to the second aspect of the present invention. The laser system according to the second aspect of the present invention comprises a beam line according to the first aspect of the present invention. In summary, the thermal laser evaporation system according to the third aspect of the present invention comprises all the advantages described above with respect to the beam line according to the first aspect of the present invention and the laser source according to the second aspect of the present invention.

[0092] In a thermal laser evaporation system, a laser can be used to evaporate or sublimate source materials or heat the materials of a substrate accordingly. Such thermal laser evaporation systems are generally known. The source materials evaporated and / or sublimated by irradiating laser beams are deposited on a substrate set as a target. Additionally or alternatively, the laser beams can also be used to heat the materials of the substrate. The source materials are provided as source elements in a source arranged in a reaction chamber, where there may be one or more sources, especially providing the same and / or different source materials. The laser beams are irradiated on the surface (in most cases, the top surface) of the source elements to provide a flux of the source materials to be evaporated or sublimated.

[0093] The source is arranged in a reaction chamber, which can be sealed relative to the ambient atmosphere and filled with a reaction atmosphere. The reaction atmosphere can be a vacuum, especially as low as 10 -12 hPa or even lower, or include a reaction gas at a pressure suitable for material deposition, such as a reaction gas providing oxygen, for the deposition of oxides of elemental or compound source materials to be evaporated and / or sublimated. The maximum value tested at a working distance of 60 mm is up to 10 -2 hPa. Higher values may be feasible because deposition can be carried out without problems at 10 -2 hPa.

[0094] For the two purposes of the laser beams (i.e., evaporation and / or sublimation of target materials and heating of substrate materials), the laser beams are generated by a laser source of a laser system according to the second aspect of the present invention and guided from the laser source to the reaction chamber through a beam line according to the first aspect of the present invention. Additionally, the use of the beam line according to the first aspect of the present invention provides the possibility of changing and / or controlling the properties of the corresponding laser beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] The present invention will be explained in detail below by way of examples and with reference to the drawings. Specifically, it is shown in the figures:

[0096] Figure 1 A thermal laser evaporation system according to the present invention is shown;

[0097] Figure 2 A first partial view of a beam line according to the present invention is shown;

[0098] Figure 3 Shown is Figure 2 a second view of the beam line;

[0099] Figure 4 Shown is Figure 2 a laser system according to the present invention with a beam line;

[0100] Figure 5 shows a laser beam guided by a beamline of Figure 2 ;

[0101] Figure 6 shows a guiding section of a beamline according to the present invention;

[0102] Figure 7 shows a possible arrangement of a joint of a modular beamline according to the present invention; and

[0103] Figure 8 shows an example of beam diagnostics using a beamline according to the present invention. DETAILED DESCRIPTION

[0104] In Figure 1 , a schematic view of a thermal laser evaporation system 300 according to the present invention is shown. Specifically, the thermal laser evaporation system 300 includes a reaction chamber 310 and a laser system 200 according to the present invention, and the laser system itself includes a support structure 212, a laser source 210, and a beamline 10 according to the present invention.

[0105] The reaction chamber 210 is filled with a reaction atmosphere 312. Additionally, a source 314 of a material to be evaporated and / or sublimated and a substrate 316 of a material to be coated are arranged in the reaction chamber 310. In the illustrated embodiment of the thermal laser evaporation system 300, the laser beam 200 provided by the laser system 200 is used for the evaporation and / or sublimation of the material of the source 314. However, the substrate 316 can also be heated by a laser beam 220, which can also be provided by a laser system 200 with a corresponding configuration according to the present invention.

[0106] As described above, the laser system 200 includes a laser source 210 that generates a laser beam 220. Preferably, the laser beam 220 can be an infrared laser beam 220, for example, having a wavelength of about 10 μm. The beamline 10 according to the present invention is used to guide the laser beam 220 from the laser source 210 to the reaction chamber 310. The common support structure 212 of the laser system 200 supports both the laser source 210 and the beamline 10 accordingly, and thus, on the one hand, provides a firm fixation and mechanical support for the elements of the laser system 200, and on the other hand, ensures a fixed relative positioning of the laser source 210 and the beamline 10 relative to each other.

[0107] The beam line 10 extends between a source end 20 and a chamber end 30. The source end 20 is formed by a laser entrance section 22 which is hermetically and optically connected to a laser source 210. The laser entrance section 22 already includes a planar mirror 82 for deflecting the laser beam 220. Similarly, the chamber end 30 is formed by a chamber exit section 32 which is also hermetically and optically connected to a reaction chamber 310. Specifically, the chamber exit section 32 includes a chamber window 36 which can be arranged at a corresponding flange of the reaction chamber 310.

[0108] In the illustrated embodiment, the beam line 10 is a modular beam line 10 which includes two guiding sections 52 and two optical sections 50. All sections 50, 52 share the same connection interfaces 64, 70 (see Figure 2 , Figure 6 ), and can be arranged adjacent to each other in any order. Specifically, all sections 50, 52 are mechanically rigid or at least substantially hardenable. Additionally, the sections 50, 52 can be connected in pairs by a correspondingly configured first connection interface 64 (provided at the upstream end 60 of the corresponding section 50, 52) and a second connection interface 70 (provided at the downstream end 66 of the corresponding section 50, 52), so that this connection is also mechanically rigid ( Figure 2 , Figure 6 ). In other words, the beam line 10 according to the present invention is preferably self - supporting.

[0109] The optical section 50 is used to change and / or control the properties of the laser beam 220, for example, the direction of the laser beam 220 as shown. The guiding section 52 extends linearly and straightly. In summary, the beam line 10 according to the present invention provides a hermetic and optically tight connection between the laser source 210 and the reaction chamber 310, wherein the laser beam 220 is guided within the beam line 10, and wherein further properties of the laser beam 220 are changed and / or controlled to meet the operating requirements of the thermal laser evaporation system 300.

[0110] Figures 2 to 4 A possible embodiment of the beam line 10 according to the present invention and a corresponding laser system 200 according to the present invention having said beam line are shown. Additionally, Figure 5 the laser beam 220 guided through the beam line 10 is shown, wherein a part where the properties of the laser beam 220 change along its path through the beam line 10 is shown. In the following, Figures 2 to 5 they will be described together.

[0111] Figure 2 The optical section 50 of the beam line 10 is specifically shown. To make the laser beam 220 visible, the guiding section 52 is not shown (see Figure 3 , Figure 4)。This allows the three downstream ends 66 of the optical section 50 to be shown. Since the beam line 10 is also a modular beam line 10, the visible downstream ends 66 represent all downstream ends 66 and correspond to the upstream ends 60 of the corresponding configurations of all sections 50, 52 (see Figure 6 ). All downstream ends 66 include a second section opening 68 of the corresponding section cavity 56 and a second connection interface 70 with an elastomeric seal 72 that surrounds the second section opening 68 for a gas-tight and light-tight connection.

[0112] In addition, a laser entrance section 22, a chamber exit section 32, and a substrate 316 (in the illustrated embodiment, the substrate is the destination of the laser beam 220) are shown. Similar to Figure 1 the embodiment shown in, the chamber exit section 32 includes a chamber window 36 that can be arranged at the corresponding flange of the reaction chamber 310 of the thermal laser evaporation system 300 (see Figure 1 ). In addition, the illustrated chamber exit section 32 includes a bellows 34 to mechanically decouple the laser system 200 including the beam line 10 from the reaction chamber 310 (decoupling), for example, to prevent vibration transmission between the corresponding components of the thermal laser evaporation system 300.

[0113] The illustrated beam line 10 includes six optical sections 50, where each optical section serves as a mechanical support for an optical element 80 that changes and / or controls the properties of the laser beam 220. The optical element 80 is also shown in Figure 5 . Note that all optical elements 80 (except for the aperture 94) are provided as mirrors and are shown as lenses in Figure 5 for illustrative purposes only. All optical elements 80 provided as mirrors reflect the incident laser beam 220 at 90°, thus at least changing the direction of the laser beam 220.

[0114] Preferably, the optical element 80 (or at least the active part of the corresponding optical element 80) is machined from a solid block of metal, particularly copper or aluminum. This applies to the mirrors 82, 84, 86, 88, 90, and the aperture 94. This allows for the provision of optical elements 80 with high precision in their optical properties. In addition, the metal, particularly copper, has high thermal conductivity. Therefore, the laser energy deposited in the corresponding optical element 80 is evenly distributed within the optical element 80. In addition, cooling of the metal block can be easily provided, particularly cooling channels for the corresponding cooling tool 100 can be directly machined into the solid block of metal forming the optical element 80.

[0115] In addition, in Figure 5Laser beam 220 is shown. On the right side, it successively passes through optical elements 80, and on the left side immediately adjacent to these optical elements, the intensity profile represents the local intensity distribution of laser beam 220.

[0116] As Figure 5 shown, laser beam 220 is always parallel to central axis C in beam line 10. This is provided in particular by the configuration of each optical section 80, i.e., laser beam 220 entering section cavity 56 of the corresponding optical section 50 parallel to the central axis C of the corresponding first section opening 62 (see Figure 6 ) leaves section cavity 56 parallel to the central axis C of the corresponding second section opening 68. Additionally, section cavity 56 of guiding section 52 (see Figure 3 , Figure 4 , Figure 6 ) extends linearly from first section opening 62 to second section opening 68 along the common central axis C of the first section opening 62 and the second section opening 68 of the corresponding guiding section 52.

[0117] Furthermore, preferably, the intensity distribution of laser beam 220 is rotationally symmetric, or has twofold symmetry if all joints have a rotation that is an integer multiple of 180°; has threefold symmetry if all joints have a rotation that is an integer multiple of 120°; has fourfold symmetry if all joints have a rotation that is an integer multiple of 90°; has fivefold symmetry if all joints have a rotation that is an integer multiple of 72°; has sixfold symmetry if all joints have a rotation that is an integer multiple of 60°; has eightfold symmetry if all joints have a rotation that is an integer multiple of 45°, and so on.

[0118] Please refer to Figure 2 and Figure 5, the laser beam originating from the laser source 210 first impinges on the focusing mirror 84. Subsequently, the optical section 50 having the defocusing mirror 86 as the optical element 80 follows. Thus, this first pair of optical sections 50 forms a beam telescope, thereby substantially changing the radius of the laser beam 220 and thus its size. At least the defocusing mirror 86 (preferably also the focusing mirror 84) is configured as an adjustable mirror, in particular as a reflective film located on a cushion. The amount of fluid in the cushion can be adjusted by an adjustment connector 102 that can be used from the outside of the beam line 10. Thus, by adjusting the filling of the respective cushions of the defocusing mirror 86 and / or the focusing mirror 84, the size of the laser beam can be actively adjusted during the operation of the laser system 200.

[0119] The optical section having the conical mirror 88 is arranged directly 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 50 having the conical mirror 88 form a joint 16 of the modular beam line 10. The conical mirror 88 changes the spatial shape of the intensity distribution of the laser beam 220, see Figure 5 .

[0120] Downstream, an optical section 50 having a complementary conical mirror 88 (formed as a free-form mirror 90, which also acts as the focusing mirror 84) restores the change in the intensity distribution of the laser beam 220. The free-form mirror 90 is further configured as an adjustable mirror, and its spatial orientation can be adjusted by an adjustment screw 100 that can be used from the outside of the beam line 10.

[0121] However, between the two conical mirrors 88, an optical section 50 having a hole 94 as the optical element 80 is arranged, and the hole selectively cuts the outside of the laser beam 220 and thus changes the shape of the intensity distribution of the laser beam 220.

[0122] As described in the previous paragraph, the hole 94 is used to cut the laser beam 220, in particular by absorbing a part of the laser beam 220. To prevent damage caused by the absorbed laser energy, the hole 94 is equipped with a cooling tool 110. The cooling tool may include, for example, a coolant flowing through a cooling pipe located within the hole 94. Preferably, the inlet and / or outlet of the coolant can be used from the outside of the beam line 10.

[0123] In the specific embodiment shown, the upstream face of the hole 94 is coated with an oxide absorption layer, which is preferably a rough, plasma-sprayed sapphire layer having a thickness of 0.5 mm. This helps to absorb the excess laser of the laser beam 220, so that this layer is in direct and close contact with the fluid-cooling body of the hole 94 and thereby efficiently conducts heat to the fluid-cooling pipe of the cooling tool 110.

[0124] Finally, the last optical section 50 includes a Bragg mirror 92 as the optical element 80, which on the one hand provides a wavelength-selective reflection of the laser beam 220 by 90°, and on the other hand allows the pyrometer 122 to be implemented as the diagnostic tool 120 to directly measure the temperature of the object heated by the laser beam 220, see Figure 4 .

[0125] In addition, the above-mentioned optical section 50 with the free-form mirror 90 and the optical section 50 with the Bragg mirror 92 are arranged directly adjacent to each other. Thus, the optical sections 50 form the second joint 16 of the modular beam line 10.

[0126] In addition to Figure 2 the part of the beam line 20 already shown in Figure 3 a guiding section 52 is also shown. All the guiding sections 52 are arranged between the optical sections 50 to form the beam line 10. The section cavities 56 in the corresponding housings 54 of the guiding sections 52 are connected to the corresponding section cavities 56 of the optical sections 50 to form a continuous beam cavity 12 extending between the source end 20 and the chamber end 30 of the beam line 10. Specifically, the beam cavity 12 is an airtight and lighttight volume. Therefore, it is possible to provide a flow of purge gas 42 (such as pure nitrogen and / or dry air) in the beam cavity 12, which is provided by the gas system 40 and flows from the inlet 44 provided in the laser inlet section 22 to the outlet 46 provided in the chamber outlet section 32. However, the gas system 40 may also have alternative and unshown arrangements, where the inlet 44 is located at the chamber outlet section 32 and the outlet 46 is located at the laser inlet section 22, or even the inlet 44 or the outlet 46 is located somewhere along the beam cavity 12 and the corresponding outlet 46 or inlet 44 is located at one or both ends of the beam cavity 12.

[0127] Finally, in Figure 4 the laser source 210 and the aforementioned pyrometer 122 are also shown.

[0128] Figure 6Shows a possible embodiment of the guiding section 52, where the housing 54 is provided as an extruded aluminum section. An isometric view is shown in subfigure A and a cross-sectional view of the guiding section 52 is shown in subfigure B. Subfigure A particularly shows the upstream end 60 or the corresponding guiding section 52, whose first section opening 62 provides an entrance to the section cavity 56 of the guiding section 52, and the section cavity basically forms part of the beam cavity 12 of the beam line (see Figures 2 to 4 ). Preferably, at least the surface 58 of the section cavity 56 is anodized to provide a thicker oxide layer, thereby absorbing any scattered part of the laser beam 220.

[0129] In addition, a first connection interface 64 is arranged at the upstream end 60, which includes, for example, an elastomeric seal 72 around the first section opening 62 (see subfigure B) and threaded holes 76 for making an airtight and lighttight connection with a correspondingly configured second connection interface 70 located on the downstream end 66 of the optical section 50 (see Figure 2 ). The threaded holes 76 are arranged in a 90° rotationally symmetric pattern in the upstream end 60. The grooves 74 in the housing 54 of the guiding section 52 allow for firm and particularly easy fixation on an external support structure 212 (see Figure 1 ).

[0130] In Figure 7 , the joints 16 of the modular beam line 10 according to the present invention are depicted in six exemplary configurations shown in subfigures A to F. The joint 16 is formed by a pair of optical sections 50 that change and / or control the direction of the laser beam 220, and this pair of optical sections are arranged on top of each other using their respective first connection interfaces 64 (not shown) and second connection interfaces 70 (see Figure 2 ). Each optical section 50 can change the direction of the laser beam 220 by 90°, where the laser beam 220 remains parallel to the spatially existing central axis C throughout the joint 16. Depending on the relative rotational orientation of the two optical sections 50 with respect to each other and depending on the relative rotational orientation of each optical section 50 with respect to the adjacent guiding section 52 arranged therewith, by rotating and / or pivoting the joint 16, almost all solid angles can be achieved with the modular beam line 10, only limited by the size of the optical section 50 forming the joint 16 that is perpendicular to the laser beam 220 and thus perpendicular to its corresponding central axis C.

[0131] Similarly, for the clarity of the example, Figure 7 the stepping of the possible angles shown in Figure 6) when, it is possible to have other integer divisions of 360° (such as 180°, 120°, 72°, 60°, 45°, 30°, 20°, 10°, 5°, etc.). When connecting the optical section 50 and / or the guiding section 52 in different ways (such as using a clamping tool), it is possible to have any rotation angle in each connection plane, thus truly allowing any angle and orientation between the first guiding section and the second guiding section 52 in the example geometry of Figure 7 Any angle and orientation between the first guiding section and the second guiding section 52 in the example geometry of

[0132] Additionally or alternatively, for the Figure 4 pyrometer 122 shown in, other possible beam diagnostic tools 120 may also be part of the beam line 10 according to the present invention. Figure 8 One of the possibilities is shown in Figure 8 Sub - figure A in shows the working mode of the thermal laser evaporation system 300 equipped with the correspondingly equipped beam line 10, and sub - figure B shows the same thermal laser evaporation system 300 in the measurement mode.

[0133] In the working mode (sub - figure A), the laser beam 220 is deflected by 90° by the optical element 80 (specifically, the Bragg mirror 92) of the last optical section 50 of the beam line 10. The optical element is arranged in the section cavity 56, which is part of the beam cavity and is enclosed by the housing 54 of the optical section 50. After deflection, the laser beam 220 enters the reaction chamber 310 filled with the reaction atmosphere 312 through the chamber window 36. In the shown embodiment, the chamber window is part of the chamber outlet section 32 of the chamber end 30 forming the beam line 10. Inside the reaction chamber 310, the laser beam 220 irradiates on the source 314 to evaporate and / or sublime the material of the source 314, or irradiates on the substrate to heat the substrate. Note that the source 314 or the substrate is at a working distance 128 from the Bragg mirror 92.

[0134] In contrast, in the measurement mode (sub - figure B), the Bragg mirror 92 is removed, and an additional beam line element 14 is attached to the optical element 50 so that it extends substantially along the direction of the laser beam 220 that initially existed at the upstream end 60 of the optical section 50. Alternatively, the additional beam line element 14 can be permanently attached to the optical section 50.

[0135] Within the beamline element 14, a detector 124 is arranged as a diagnostic tool 120, particularly at a measurement distance 126 from the initial position of the removed Bragg mirror 92. A camera, a beam monitor, a canvas, or thermal paper can be used as the detector 124. The measurement distance 126 is selected according to the working distance 128, and preferably, is the same as the working distance 128. Thus, the beam profile of the laser beam 220 at the position of the detector 124 is substantially the same as that of the laser beam 220 at the position of the source 314 or the substrate, but there may be minor deformations caused by the chamber window 36 and the Bragg mirror 92. In summary, the diagnosis of the laser beam 220 can be provided at the position of the source 314 or the substrate without breaking the closure of the reaction chamber 310.

[0136] List of reference numerals:

[0137] 10: Beamline

[0138] 12: Beam chamber

[0139] 14: Beamline element

[0140] 16: Joint

[0141] 20: Source end

[0142] 22: Laser entrance section

[0143] 30: Chamber end

[0144] 32: Chamber exit section

[0145] 34: Bellows

[0146] 36: Chamber window

[0147] 40: Gas system

[0148] 42: Purge gas

[0149] 44: Inlet

[0150] 46: Outlet

[0151] 50: Optical section

[0152] 52: Guide section

[0153] 54: Housing

[0154] 56: Section chamber

[0155] 58: Surface

[0156] 60: Upstream end

[0157] 62: First section opening

[0158] 64: First connection interface

[0159] 66: Downstream end

[0160] 68: Second section opening

[0161] 70: Second connection interface

[0162] 72: Elastomeric seal

[0163] 74: Groove

[0164] 76: Threaded hole

[0165] 80: Optical element

[0166] 82: Plane mirror

[0167] 84: Focusing mirror

[0168] 86: Defocusing mirror

[0169] 88: Conical mirror

[0170] 90: Freeform mirror

[0171] 92: Bragg mirror

[0172] 94: Hole

[0173] 100: Adjusting screw

[0174] 102: Adjusting connector

[0175] 110: Cooling tool

[0176] 120: Diagnostic tool

[0177] 122: Pyrometer

[0178] 124: Detector

[0179] 126: Measuring distance

[0180] 128: Working distance

[0181] C: Central axis

[0182] 200: Laser system

[0183] 210: Laser source

[0184] 212: Support structure

[0185] 220: Laser beam

[0186] 300: Thermal laser evaporation system

[0187] 310: Reaction chamber

[0188] 312: Reaction atmosphere

[0189] 314: Source

[0190] 316: Substrate

Claims

1. A beam line (10) for a laser beam (220) of a thermal laser evaporation (TLE) system (300), the beam line (10) extending between a source end (20) and a chamber end (30) of the beam line (10), whereby the source end (20) can be connected to a laser source (210) and the chamber end (30) can be connected to a reaction chamber (310) of the TLE system (300). The beam line (10) includes two or more of the following: One or more optical sections (50) for changing and / or controlling the properties of the laser beam (220), and / or One or more linear guiding sections (52); Among them, Each of the optical sections (50) and the guiding sections (52) respectively includes a housing (54), the housing having an upstream end (60) including a first connection interface (64), a downstream end (66) including a second connection interface (70), and a section cavity (56), the section cavity continuously extending within the housing (54) from a first section opening (62) located in the upstream end (60) to a second section opening (68) located in the downstream end (66). Wherein, the one or more optical sections (50) and the one or more guiding sections (52) are arranged adjacent to each other in pairs such that the corresponding section cavities (56) form a continuous beam cavity (12) extending from the source end (20) to the chamber end (30), and Wherein, each section pair of adjacent optical sections (50) and / or guiding sections (52) is arranged by connecting the first connection interface (64) of one section of the section pair to the second connection interface (70) of the other section of the section pair.

2. The beam line (10) according to claim 1, Among them, The first connection interface (64) and the second connection interface (70) are adapted to each other to provide an airtight and / or lighttight connection of the corresponding section cavity (56).

3. The beam line (10) according to claim 2, Among them, Both the first connection interface (64) and the second connection interface (70) include one or more corresponding arrangement spaces for precisely assembling alignment elements of the beam line (10), the alignment elements being used to align the section pairs of adjacent optical sections (50) and / or guiding sections (52).

4. The beam line (10) according to claim 3, Among them, The arrangement space surrounds the corresponding section openings (62, 68), and the alignment element is annular, and / or Wherein, the arrangement space is a hole, and the alignment element is a screw or a bolt for fixing the corresponding section pairs of adjacent optical sections (50) and / or guiding sections (52) to each other.

5. The beam line (10) according to any one of the preceding claims 2 to 4, Among them, To provide an airtight and / or lighttight connection of the respective section cavity (56), the first connection interface (64) includes an elastomeric seal (72) surrounding the first section opening (62), and / or the second connection interface (70) includes an elastomeric seal (72) surrounding the second section opening (68).

6. The beamline (10) according to any one of the preceding claims 1 to 5, Among them, The one or more optical sections (50) include optical elements (80) arranged in the respective section cavities (56), wherein the optical elements (80) are capable of changing and / or controlling one or more properties of a laser beam (220) entering the section cavity (56) through the first section opening (62), such that the altered laser beam exits the section cavity (56) through the second section opening (68).

7. The beamline (10) according to claim 6, Among them, The optical element (80) is capable of changing and / or controlling the laser beam (220) such that a 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).

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

9. The beamline (10) according to any one of the preceding claims 1 to 8, Among them, The section cavities (56) of the one or more guiding sections (52) linearly extend 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).

10. The beamline (10) according to any one of the preceding claims 1 to 9, Among them, The beamline (10) includes a laser inlet section (22), wherein the laser inlet section (22) forms the source end (20), includes a second connection interface (70), and is capable of connecting to the laser source (210) in an airtight and / or lighttight manner, and / or wherein the beamline (10) includes a chamber outlet section (32), wherein the chamber outlet section (32) forms the chamber end (30), includes a first connection interface (64), and is capable of connecting to the reaction chamber (310) in an airtight and / or lighttight manner.

11. The beamline (10) according to claim 10, Among them, The chamber outlet section (32) includes a bellows (34), and / or the laser inlet section (22) includes a bellows (34).

12. The beamline (10) according to claim 10 or 11, Among them, The chamber outlet section (32) includes a chamber window (36), which can be arranged at the flange of the reaction chamber (310).

13. The beamline (10) according to any one of the preceding claims 1 to 12, Among them, The beamline (10) includes a gas system (40) for providing a flow of purge gas (42) within the beam chamber (12).

14. The beamline (10) according to claim 13, Among them, one or more inlets (44) of the gas system (40) for injecting the purge gas (42) into the beam chamber (12), and one or more outlets (46) of the gas system (40) for extracting the purge gas (42) from the beam chamber (12) are connected to the beam chamber (12) to provide a flow of the purge gas (42) within substantially the entire beam chamber (12) between the source end (20) and the chamber end (30).

15. The beamline (10) according to claims 10 and 14, Among them, The inlet (44) is connected to the laser inlet section (22), and the outlet (46) is connected to the chamber outlet section (32).

16. The beamline (10) according to claims 10 and 14, Among them, The outlet (44) is connected to the laser inlet section (22), and the inlet (44) is connected to the chamber outlet section (32).

17. The beamline (10) according to claims 10 and 14, Among them, one inlet (44) is connected to the laser inlet section (22), and one inlet (44) is connected to the chamber outlet section (32), and one outlet (46) is connected to the beam chamber between the source end (20) and the chamber end (30), or wherein, one outlet (46) is connected to the laser inlet section (22), and one outlet (46) is connected to the chamber outlet section (32), and one inlet (44) is connected to the beam chamber between the source end (20) and the chamber end (30).

18. The beamline (10) according to any one of claims 13 to 17, Among them, Dry air or pure nitrogen is used as the purge gas (42).

19. The beamline (10) according to any one of the preceding claims 1 to 18, Among them, The respective housings (54) of the one or more optical sections (50) and the one or more linear guide sections (52) are mechanically rigid or at least substantially hardenable, and wherein the first connection interface (64) and the second connection interface (70) are adapted to each other to provide a mechanically rigid connection.

20. The beamline (10) according to any one of the preceding claims 1 to 19, Among them, The housing (54) of the one or more linear guide sections (52) is a tubular extruded aluminum section.

21. The beamline (10) according to claim 20, Among them, Grooves (74) for fixing to the support structure (212) are provided on the outer surface (58) of the housing (54).

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

23. The beamline (10) according to claim 22, Among them, Two or more threaded holes (76) are arranged around the central axis (C) of the corresponding first section opening (62) and / or second section opening (68) in a rotationally symmetric pattern, specifically in a 180° or 120° or 90° or 72° or 60° or 45° or 40° or 30° or 20° or 10° or 5° rotationally symmetric pattern, around the corresponding said first section opening (62) and / or second section opening (68).

24. The beamline (10) according to claim 22 or 33, Among them, The first connection interface (64) and the second connection interface (70) are arranged rotationally symmetrically, and thus, the beamline (10) includes a clamping tool for firmly fixing adjacent pairs of optical sections (50) and / or guiding sections (52).

25. The beamline (10) according to any one of the preceding claims 1 to 24, Among them, The surface (58) of the section cavity (56) is anodized to provide an oxide layer on the surface (58) of the section cavity (56).

26. The beamline (10) according to any one of the preceding claims 1 to 25, Among them, The one or more optical sections (50) change and / or control one or more of the following properties of the laser beam (220): - Direction; - Size; - Shape; - Polarization; - Focal length; and - Intensity distribution.

27. The beamline (10) according to claim 26, Among them, The corresponding optical elements (80) of the one or more optical sections (50) include one or more of the following elements: - Plane mirror (82); - Focusing mirror (84); - Defocusing mirror (86); - Conical mirror (88); - Freeform mirror (90); - Bragg mirror (92); - Diffractive mirror or grating; and - Hole (94).

28. The beamline (10) according to claim 26 or 27, Among them, The active components of the corresponding optical elements (80) of the one or more optical sections (50) are machined from a single piece of metal, especially copper.

29. The beamline (10) according to any one of claims 25 to 28, Among them, The optical elements (80) of the one or more optical sections (50) include actively adjustable mirrors.

30. The beamline (10) according to claim 29, Among them, The spatial orientation of the actively adjustable mirror can be adjusted by adjusting screws (100), and / or wherein the actively adjustable mirror includes a reflective film located on a cushion that can be filled with an adjusting fluid.

31. The beamline (10) according to claim 30, Among them, The adjusting screws (100) and / or the adjusting connectors (102) for the adjusting fluid can be used from the outside of the housing (54) of the corresponding optical section (50).

32. The beamline (10) according to any one of the preceding claims 1 to 31, Among them, The one or more optical sections (50) include a cooling tool (110) for actively cooling the respective optical element (80).

33. The beam line (10) according to claims 28 and 32, Among them, The cooling tool (110) includes a cooling duct for a coolant, the cooling duct being machined in and / or into the monolithic metal forming the active part of the respective optical element (80).

34. The beam line (10) according to any one of claims 1 to 33, Among them, The beam line (10) includes a beam diagnostic tool (120) for measuring properties of the laser beam (220).

35. The beam line (10) according to claim 34, Among them, The beam diagnostic tool (120) includes a pyrometer (122) for measuring the temperature of the optical element (80) of one of the optical sections (50).

36. The beam line (10) according to claim 34 or 35, Among them, The optical element (80) of one of the optical sections (50) that changes the direction of the laser beam (220) by 90°, specifically a Bragg mirror (92), can be removed, and an additional beam line element (14) is arranged and / or can be arranged at the position of the optical element (80) or along the initial direction of the laser beam (220), wherein the beam diagnostic tool (120) includes a detector (124) arranged at a measurement position in the additional beam line element (14).

37. The beam line (10) according to claim 36, Among them, One of the optical sections (50) is the last optical section (50) before the chamber end (30), and the measurement distance (126) from the measurement position to the position of the removed optical element (80) is selected according to the working distance (128) from the removed optical element (80) to the substrate (316) or source (314) in the reaction chamber (310), preferably the measurement distance is equal to the working distance.

38. The beam line (10) according to claim 36 or 37, Among them, The detector (124) is a camera and / or a beam monitor and / or a canvas and / or a thermal paper.

39. The beam line (10) according to any one of the preceding claims 1 to 38, Among them, The beam line (10) is a modular beam line (10) that includes a plurality of optical sections (50) and / or guiding sections (52) as modules.

40. The beam line (10) according to claim 39, Among them, A pair of optical sections (50) that change and / or control the direction of the laser beam (220) are arranged on top of each other by using their respective first connection interfaces (64) and second connection interfaces (70) to form a joint (16) of the modular beam line (10), wherein the modular beam line (10) can be rotated and / or pivoted at the joint (16) by rotating the optical sections (50) relative to each other.

41. The beam line (10) according to claim 40, Among them, The optical section (50) is constructed according to claim 6.

42. A laser system (200) for a thermal laser evaporation (TLE) system (300), comprising a laser source (210) for providing a laser beam (220) and a beam line (10) for guiding the laser beam (220) from the laser source (210) to a reaction chamber (310) of the TLE system (300), Among them, The beam line (10) is constructed according to any one of the preceding claims 1 to 41.

43. The laser system (200) according to claim 42, Among them, The laser system (200) includes a support structure (212), and wherein the laser source (210) and the beam line (10) are arranged at the support structure (212).

44. The laser system (200) according to claim 42 or 43, Among them, The laser source (210) provides an infrared laser beam (220) having a wavelength between 0.1 μm and 1000 μm, preferably 10 μm, and in particular wherein, The laser source (210) is a CO2 laser source (210).

45. A Thermal Laser Evaporation (TLE) system (300), comprising: A reaction chamber (310) that can be filled with a reaction atmosphere (312); A substrate (316) arranged in the reaction chamber (310); One or more sources (314) arranged in the reaction chamber (310); and a laser system (200) for providing a laser beam (220) to evaporate and / or sublime the material of the source (314) and / or heat the material of the substrate (316), wherein the laser system (200) is constructed according to any one of the preceding claims 42 to 44.

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