Source device and thermal laser epitaxy system

Abstract

The present invention relates to a source apparatus for a thermal laser epitaxy (TLE) system (100), comprising a holding device (20) including a movable holding structure (22) having one or more holding spaces (24) for positioning one or more source elements (120) that provide raw materials to be evaporated and / or sublimated by a laser beam (130) of the TLE system (100) for coating a substrate (110) of the TLE system (100). The present invention further relates to a thermal laser epitaxy (TLE) system (100) for coating a surface of a substrate (110) with a layer comprising one or more raw materials, the TLE system (100) comprising a reaction chamber (112) enclosing a reaction volume that is sealable against the surrounding atmosphere, a gas system (100) for providing an adjustable reaction atmosphere in the reaction volume, positioning means for positioning the substrate (110) in the reaction volume, substrate (110) heating means for heating the substrate (110), a laser system (100) for providing one or more laser beams (130) for evaporating and / or sublimating the one or more raw materials, and a source device (100) for supplying the one or more raw materials into the reaction chamber (112).

Description

[Technical Field]

[0001] The present invention relates to a source apparatus for a thermal laser epitaxy (TLE) system, the source apparatus comprising a holding device including a movable holding structure having one or more holding spaces for arranging one or more source elements for supplying raw materials to be evaporated and / or sublimated by a laser beam of the TLE system for coating a substrate of the TLE system. Furthermore, the present invention relates to a thermal laser epitaxy (TLE) system for coating a surface of a substrate with a layer including one or more raw materials, the TLE system comprising: a reaction chamber enclosing a reaction volume that can be sealed against the surrounding atmosphere; a gas system for providing an adjustable reaction atmosphere in the reaction volume; a positioning means for positioning a substrate in the reaction volume; a substrate heating means for heating the substrate; a laser system for providing one or more laser beams for evaporating and / or sublimating the one or more raw materials; and a source apparatus for supplying the one or more raw materials into the reaction chamber. [Background technology]

[0002] In thermal laser epitaxy systems, a laser beam is directed at a source element that supplies raw material, causing it to evaporate or sublimate. The laser beam is directed at an angle relative to the source element so that the evaporation flux, directed approximately perpendicular to the surface of the source element, reaches the substrate to be coated without interference with the laser beam shaping and guiding components. For example, both the laser beam and the source can be moved slightly to change the size, position, and / or shape of the laser beam projection on the source element and / or to compensate for material loss due to the evaporation and / or sublimation process. The focal position of the laser beam is often fixed away from the source element to allow for the placement of an aperture to mitigate coating of upstream optics.

[0003] However, in many practical applications, one may wish to vary the working distance between the source elements and the substrate to be coated significantly, for example, to change the deposition gradient along the substrate or to space sources at widely differing operating temperatures at large distances. One may also wish to increase the beam projection range on the source by using the same laser at different working distances for the same source, or to use different sources for the same laser. Source devices known in the prior art cannot meet these requirements. Summary of the Invention [Problem to be solved by the invention]

[0004] In light of the above, it is an object of the present invention to provide an improved source apparatus and an improved thermal laser epitaxy system that do not have the problems of the prior art, and in particular to provide an improved source apparatus and an improved thermal laser epitaxy system that allow the same laser beam to be used to evaporate and / or sublimate source elements, in particular raw materials, that are supplied from the same source element and / or different source elements at different working distances relative to the substrate to be coated.

[0005] The object of the present invention is achieved by the respective independent claims, in particular by a source device according to claim 1 and a thermal laser epitaxy system according to claim 19. The dependent claims describe preferred embodiments of the invention. Details and advantages described for the source device according to the first aspect of the invention also apply, where technically meaningful, to the thermal laser epitaxy system according to the second aspect of the invention, and vice versa. [Means for solving the problem]

[0006] According to a first aspect of the present invention, the object of the present invention is achieved by a source apparatus for a thermal laser epitaxy (TLE) system, comprising: a holding apparatus including a movable holding structure having one or more holding spaces for disposing one or more source elements that supply raw materials to be evaporated and / or sublimated by a laser beam of the TLE system for coating a substrate of the TLE system, The source apparatus according to the present invention further comprises an actuator mechanically coupled to the holding structure, the actuator being configured to move the holding structure between two or more holding positions, wherein at a first holding position among the two or more holding positions, one of the one or more source elements disposed in each of the holding spaces is located at a first interaction position along the laser beam, and at a second holding position among the two or more holding positions, one of the one or more source elements disposed in each of the holding spaces is located at a second interaction position along the laser beam that is different from the first interaction position.

[0007] The source device according to the present invention is configured for use in a TLE system. The purpose of the source device in a TLE system, particularly in a reaction chamber of a TLE system, is to provide one or more source elements that supply raw materials that are evaporated and / or sublimated by one or more laser beams of the TLE system. The evaporated and / or sublimated raw materials are deposited on a substrate to form an epitaxial layer on the substrate.

[0008] To accommodate the one or more source elements, the source device of the present invention includes a holding structure having one or more holding spaces for arranging each source element. The holding spaces are configured to accommodate each source element, for example, by conformably surrounding the source element and / or by providing appropriately configured fastening means, such as screws or clamps, for fastening each source element to the respective holding spaces. Typical sizes of source elements for TLE systems, particularly those used for research purposes, are 8 mm in height and 2 to 12.7 mm in diameter; therefore, each holding space for such source elements has correspondingly selected dimensions. Adapters can also be used to appropriately reduce the size of the available space in the holding space to the size of each source element. Alternatively, a holding structure can be used in which source elements are pre-fixed in each holding space.

[0009] The holding structure is movable and is mechanically coupled to an actuator for moving the holding structure between at least two or more different holding positions, and the actuator may include, for example, an electric motor and additional gear means and / or mechanical transmission elements for moving the holding structure.

[0010] In particular, the holding structure driven by the actuator can be positioned at least in a first holding position and a second holding position, and the first holding position and the second holding position are different. In other words, the actuator moves the entire holding structure between two different holding positions, the first holding position and the second holding position. In the present invention, "different" particularly means that the difference between the first holding position and the second holding position is not slight but clearly distinguishable, and preferably the holding structure is moved between the two holding positions by 5 mm or more, in particular 10 mm or more, and preferably 25 mm or more.

[0011] The relative positions of the two or more holding spaces in the holding structure are fixed, i.e., when the holding structure is moved between two or more holding positions by an actuator, all of the holding spaces automatically move accordingly.

[0012] According to the present invention, the first and second holding positions of the holding structure are not only different but also interconnected by their respective relative positions with respect to the laser beam of the TLE system when implemented in each TLE system. In particular, the two different holding positions of the holding structure are selected so that not only are each holding space positioned such that a source element arranged in one of the holding spaces is located at an interaction position of the laser beam, but also such that the first interaction position associated with the first holding position of the holding structure is different from the second interaction position associated with the second holding position of the holding structure. Furthermore, "different" in the present invention particularly means that the difference between the first and second holding positions is not slight but clearly distinguishable, preferably with a distance along the laser beam of at least 5 mm, in particular at least 10 mm, and preferably at least 25 mm. The interaction position in the present invention refers to the position along the laser beam at which a source element arranged in a holding space is irradiated with the laser beam, assuming that the holding structure and thus the holding space are in an appropriately selected position.

[0013] In summary, the source device of the present invention allows for the placement of source elements at two or more different interaction positions along the laser beam of a TLE system. The laser beam of the TLE system used to evaporate and / or sublimate raw material is positioned within the TLE system at an angle to the surface of the substrate. This is because a laser beam positioned parallel to the surface of the substrate is not an efficient position for depositing the evaporated and / or sublimated raw material on the surface of the substrate. The two or more interaction positions simultaneously have different distances from the surface of the substrate. In other words, by using the source device of the present invention in a TLE system, the same laser beam can be used to evaporate and / or sublimate raw material provided by source elements at different working distances from the surface of the substrate.

[0014] Furthermore, the source device of the present invention may be configured such that, when the source device is installed, the substrate distance from the second holding position to the substrate is greater than the substrate distance from the first holding position to the substrate. In this particular embodiment, when the source device of the present invention is installed, the holding structure at the second holding position is positioned further from the substrate than the holding structure at the first holding position in the TLE system. As a result, when the holding structure is positioned at the second holding position, the holding space is also positioned further from the substrate. Designating the second holding position as being further from the substrate makes it possible to plan or at least facilitate the coating process of the substrate in the TLE system, particularly taking into account the different substrate distances of the source elements to the substrate resulting from different holding positions of the holding structure.

[0015] Additionally or alternatively, the source device according to the present invention can be characterized in that the second interaction location is downstream of the laser beam relative to the first interaction location. As mentioned above, the laser beam of a TLE system is angled relative to the surface of the substrate. Therefore, by defining a second interaction location downstream of the laser beam relative to the first interaction location, two different distances between these interaction locations and the substrate can be provided. This allows for easy evaporation and / or sublimation of raw material delivered from the source element at different working distances relative to the substrate to be coated.

[0016] According to another embodiment of the source device of the present invention, the actuator is configured to linearly move the holding structure and / or to rotate the holding structure. Preferably, the actuator is configured to linearly move the holding structure and to rotate the holding structure. More preferably, the axis of the rotational movement of the holding structure provided by the actuator is parallel to the direction of the linear movement of the holding structure also provided by the actuator. Alternatively, or in addition, the direction of the linear movement may be adjusted to be perpendicular to the surface of the substrate. The linear and rotational movements are very simple movements that can be easily determined and controlled, especially with regard to the distance that can be provided from the surface of the substrate of the source elements arranged in the holding space. Therefore, providing the linear and rotational movements to the holding structure can simplify the source device of the present invention, and in particular a TLE system including such a source device.

[0017] According to a further improved embodiment of the source device according to the invention, the linear movement of the holding structure is parallel to the average direction of the evaporated and / or sublimated raw material of each of the source elements upon irradiation with the laser beam. The average direction of the evaporated and / or sublimated raw material is the most appropriate direction in which the substrate to be coated should be positioned. In most cases, the average direction is perpendicular to the surface of each of the source elements, and the substrate is positioned in the TLE system so that the average direction is also perpendicular to the surface of the substrate. Positioning the linear movement parallel to the average direction ensures that the average direction of the evaporated and / or sublimated raw material remains the same at both holding positions, i.e., the first and second holding positions related by the linear movement. Positioning the substrate as described in this paragraph allows for an optimal flow of evaporated and / or sublimated raw material to be coated onto the substrate.

[0018] Additionally or alternatively, the source device according to the present invention can be further improved by aligning the axis of the rotational movement of the holding structure parallel to the average direction of the evaporated and / or sublimated raw material irradiated by the laser beam of each of the source elements arranged in each of the holding spaces. As described above, the average direction of the evaporated and / or sublimated raw material is the most appropriate direction in which the substrate to be coated should be positioned. By aligning the axis of rotational movement parallel to the average direction, the average direction of the evaporated and / or sublimated raw material remains the same at both holding positions, i.e., the first holding position and the second holding position, which are also related by the rotational movement. By positioning the substrate as described in this paragraph, the evaporated and / or sublimated raw material can be coated onto the substrate with an optimal flow.

[0019] Furthermore, the source device according to the present invention is characterized in that a first holding space that can be positioned at the first interaction position along the laser beam when the holding structure is in its first holding position is the same as a second holding space that can be positioned at the second interaction position along the laser beam when the holding structure is in its second holding position. In other words, source elements positioned in the holding spaces are irradiated with the laser beam at both holding positions of the holding structure, and the same raw material is evaporated and / or sublimated. Since the flow of evaporated and / or sublimated raw material decreases as the distance to each source element increases, coatings of the same raw material but with different flow rates of evaporated and / or sublimated raw material can be applied to a substrate.

[0020] Alternatively, or in addition, the source device of the present invention may be configured such that a first holding space that can be positioned at the first interaction position along the laser beam when the holding structure is in its first holding position is different from a second holding space that can be positioned at the second interaction position along the laser beam when the holding structure is in its second holding position. In other words, different holding spaces are positioned along the path of the laser beam at the first and second holding positions of the holding structure. When source elements supplying the same raw material are positioned in the different holding spaces, the same advantages as described in the previous paragraph are achieved. However, when source elements supplying different raw materials are positioned in the different holding spaces, quick and easy switching between evaporation and / or sublimation of the different raw materials is possible simply by moving the holding structure of the source device between its holding positions. This facilitates the formation of a layer structure of a coating on a substrate.

[0021] According to a further improved embodiment of the source device according to the invention, the first and second holding spaces are arranged on a holding plane in the holding structure, the holding plane being perpendicular to the average direction of evaporation and / or sublimation of the source elements arranged in the respective holding spaces by irradiation with the laser beam. For example, the holding structure can be configured in a structure similar to a wheel with spokes. By arranging the two holding spaces, and preferably all holding spaces, of the holding structure in a plane perpendicular to the average direction of evaporation and / or sublimation of the source elements, the design of the holding structure, and thus the design of the entire source device, can be kept particularly simple.

[0022] The source device according to the present invention can be further improved by aligning the linear motion of the holding structure provided by the actuator parallel to the average direction of the raw material evaporated and / or sublimated by irradiation with the laser beam of each of the source elements disposed in the holding spaces, and by selecting a source distance between the first holding space and the second holding space in the holding plane and a plane-to-plane distance between the holding plane having the first holding space at the first interaction position and the holding plane having the second holding space at the second interaction position according to an angle of incidence of the laser beam in the TLE system irradiating the surfaces of the source elements displaceable in the first and second holding spaces. In this improved embodiment, the holding structure having a holding plane in which holding spaces are disposed is improved by appropriately selecting the source distance and the plane-to-plane distance in consideration of the laser beam used for evaporation and / or sublimation. In particular, the incident angles of the laser beam irradiating the source elements disposed in the first and second holding spaces are the same. Since the surface of the source element is substantially parallel to the holding plane, the angle of incidence of the laser beam is also the angle of the laser beam relative to the holding plane. By appropriately selecting both the source distance and the inter-plane distance in consideration of the angle of incidence of the laser beam, the arrangement of the first and second holding spaces, and therefore the arrangement of the source elements arranged in these holding spaces, at the first and second intersection positions of the laser beam can be ensured.

[0023] The source device can also be improved by selecting the source distance and the inter-plane distance such that the inter-plane distance divided by the source distance is tangent to the angle of incidence. In other words, if a laser beam is irradiated onto a source element disposed in a holding space when the holding structure is in its first holding position, the laser beam will be irradiated onto a source element disposed in a next holding space when the holding structure is in its second holding position.

[0024] The source distance, the inter-plane distance, and the beam path of the laser beam between the first and second interaction locations form a right triangle because the inter-plane distance is perpendicular to the holding plane. Therefore, since the angle of incidence between the holding plane and the laser beam is defined, selecting the source distance, the inter-plane distance, and the angle of incidence to satisfy the above relationship ensures the placement of the first and second holding spaces, and therefore the placement of any source elements placed in these holding spaces at the first and second intersection locations of the laser beam. In particular, for any pair of these variables (e.g., source distance and angle of incidence), the third variable (e.g., inter-plane distance in the above example) can be easily determined.

[0025] The source device of the present invention can also be improved by configuring the source device for use in a TLE system having at least a first laser beam and a second laser beam, thereby including at least two pairs of first and second holding spaces, where the source distance between the first and second holding spaces in each pair of holding spaces is selected according to the angle of incidence and the distance between the common planes of the laser beams. As with the single-laser beam embodiment, selecting the source distance for each pair of holding spaces according to the angle of incidence and the distance between the common planes of the laser beams ensures that the first and second holding spaces, and thus any source elements disposed therein, are positioned at the first and second intersections of the laser beams. This also applies to the case of three or more lasers and thus three or more pairs of holding spaces. However, if there are already three holding spaces, it is sufficient to form two pairs of holding spaces, one of which is part of both pairs of holding spaces.

[0026] In a first alternative refinement of the source device according to the present invention, the angles of incidence of the laser beams are different, and therefore the source distances of the pair of holding spaces are different. By providing different angles of incidence of the supplied laser beams, the evaporation and / or sublimation characteristics of the evaporated and / or sublimated raw material of each source element can be made different. This advantage can also be realized in a TLE system using the source device according to the present invention by selecting the source distances of each holding space of the pair of holding spaces to take into account the different angles of incidence.

[0027] According to a second improvement of the source device of the present invention, the angles of incidence of the laser beams and therefore the source distances of the pair of holding spaces are equal. Using the same angles of incidence for all supplied laser beams can provide similar, preferably identical, evaporation and / or sublimation characteristics for all evaporated and / or sublimated raw materials. By taking into account the uniform angles of incidence and therefore selecting the same source distances for each holding space of a pair of holding spaces, this advantage can also be realized in a TLE system using the source device of the present invention.

[0028] In a further improved embodiment of the source device of the present invention, the holding structure includes three or more holding spaces, which form a regular holding polygon. A regular polygon, and therefore a regular holding polygon, is a convex shape in a plane with a closed contour and equal sides. When a regular polygon is rotated through a specific polygon angle, calculated by dividing 360° by the number of its vertices, the polygon overlaps itself. Therefore, a holding structure whose holding spaces form a regular holding polygon can be arranged in the source device of the present invention in different rotational directions defined by the polygon angle while maintaining its relative orientation with respect to the laser beam. When the above rotational directions are realized, the correspondence between the holding spaces and the laser beam is maintained in both the first holding position and the second holding position. This improves the applicability of the source device of the present invention in a TLE system.

[0029] The source device according to the invention can be further improved by allowing the center of the holding polygon to be positioned facing the substrate in the TLE system. Within the scope of the present invention, a facing-to-substrate position is defined as a position in which the center of the holding polygon of the source device is oriented toward the surface of the substrate in a direction perpendicular to the holding polygon, and thus perpendicular to the holding plane and the average direction of the evaporated and / or sublimated source material, preferably with an impingement angle of 90°. This allows for particularly good coverage of the entire surface of the substrate by the coating of evaporated and / or sublimated source material provided by the source elements held by the source device according to the invention.

[0030] According to another improved embodiment of the source device according to the invention, the actuator is configured to rotate the holding structure around an axis perpendicular to the center of the holding polygon. As mentioned above, by rotating the holding structure through the polygon angle, the holding polygon overlaps itself. Therefore, by simply rotating the holding structure through the polygon angle, the holding spaces, and therefore any source elements arranged in each holding space assigned to each laser beam, can be changed without disrupting the alignment of the holding spaces with the laser beams, particularly in both the first and second holding positions. This allows for easy change of the source elements and thus the raw material actually used for evaporation and / or sublimation.

[0031] The source device of the present invention can also be improved by selecting the inter-plane distance depending on the incidence angle, the source distance, and the planar rotation angle between the relative rotation positions of the holding structure in its first holding position and its second holding position. The ability to rotate the holding structure provides additional freedom in selecting the variables of the holding structure's movement. Because the source distance between the holding spaces and the incidence angle of the laser beam are fixed, and especially because the holding spaces are arranged as a regular holding polygon, the rotation angle can be used to change the inter-plane distance. In particular, depending on the rotation direction relative to the direction of the laser beam, both an increase and a decrease in the inter-plane distance can be achieved. This allows the source device of the present invention to be better positioned in any available space within the TLE system. Furthermore, available space can be secured for arranging additional devices within the reaction chamber of the TLE system.

[0032] According to a second aspect of the present invention, the object of the present invention is achieved by a thermal laser epitaxy (TLE) system for coating a surface of a substrate with a layer containing one or more raw materials, the TLE system comprising: a reaction chamber enclosing a reaction volume that is sealable against the surrounding atmosphere, a gas system for providing an adjustable reaction atmosphere in the reaction volume, positioning means for positioning a substrate in the reaction volume, substrate heating means for heating the substrate, a laser system for providing one or more laser beams for evaporating and / or sublimating the one or more raw materials, and a source device for supplying the one or more raw materials into the reaction chamber. The TLE system according to the second aspect of the present invention is characterized in that the source device is configured according to the first aspect of the present invention, and one or more source elements for supplying the one or more raw materials are arranged in each holding space of the source device.

[0033] In the TLE system according to the second aspect of the invention, each source element is deployed using a source device according to the first aspect of the invention, and the TLE system according to the second aspect of the invention therefore provides the same features and advantages as those detailed above in relation to the source device according to the first aspect of the invention.

[0034] Next to the source device according to the first aspect of the invention, the TLE system according to the invention comprises at least the basic elements of a TLE system. The reaction chamber of the TLE system provides a reaction volume that can be sealed against the surrounding atmosphere. The intended deposition reaction occurs within said reaction volume. The source device and a substrate positioned by suitable positioning means are then placed within the reaction volume.

[0035] Furthermore, the reaction volume is fluidly connected to a gas system, which is used to provide an appropriately selected reaction atmosphere within the reaction volume. -12 The reaction atmosphere may be a vacuum at a pressure of 1000 kPa or less, or a gaseous reaction atmosphere containing a reactive gas appropriate for the intended deposition reaction, such as oxygen for the deposition of oxides.

[0036] The substrate is heated by a substrate heating means, preferably a substrate heating laser. In most deposition reactions, a substrate heated to an appropriate temperature improves the quality of the deposited layer. For example, the mobility of atoms and / or molecules deposited on the substrate surface is improved, thereby quickly repairing structural defects in the deposited layer.

[0037] Finally, the TLE system according to the present invention also includes a laser system, which includes one or more laser light sources for generating one or more laser beams used for evaporating and / or sublimating each raw material in the TLE system. Guide means and optical elements such as lenses, apertures, and / or mirrors are used as elements of the laser system for guiding and shaping the laser beam to the source element containing the raw material to be evaporated and / or sublimated. If the laser light source is located outside the reaction chamber, suitable coupling means, such as a chamber window located on the flange of the reaction chamber, are provided in the chamber wall of the reaction chamber and are used to couple the laser beam into the reaction volume.

[0038] By using the source device according to the first aspect of the present invention, source elements for supplying raw material can be arranged in holding spaces of a holding structure of the source device. The holding structure is movable between at least a first holding position and a second holding position by an actuator of the source device, so that the source elements arranged in each holding space also move together with the holding structure, particularly so that at each holding position, one of the source elements is arranged at an interaction position with the laser beam. In other words, in the TLE system according to the present invention, the same laser beam can be used to evaporate and / or sublimate raw material supplied from source elements arranged at different positions along the laser beam, and therefore at different working distances to the surface of the substrate.

[0039] According to another embodiment of the TLE system according to the invention, the laser source provides one or more laser beams with an angle of incidence selected from the range of >0° and <90°, in particular from the range of 30° to 60°, preferably 45°, which angle of incidence is the angle between the surface of each source element, which in a special embodiment of the source device according to the invention is the same as the holding plane.

[0040] The angle of incidence can generally be freely selected, provided that it is not parallel to the surface of the source element, since this would prevent effective evaporation and / or sublimation. Since the main flux of evaporated and / or sublimated raw materials is perpendicular to the surface of the source element, an angle of incidence of 90° must also be avoided, since this main flux is emitted parallel to the irradiating laser beam. This is undesirable because, on the one hand, it inevitably causes strong, unwanted, and possibly harmful, coatings on elements such as lenses, mirrors, or coupling means along the laser beam path, and, on the other hand, it is not possible to position the substrate in the direction of the main flux of evaporated and / or sublimated raw materials, significantly reducing the efficiency of the deposition reaction. Incident angles in the range of 30° to 60° have been found to be suitable for a wide range of deposition reactions. An incident angle of 45° in particular allows for a very simple design of the source device, as described above.

[0041] A TLE system can also be characterized in that the laser light source provides one or more laser beams that all have the same angle of incidence. As described above for the source device according to the first aspect of the present invention, the angles of incidence of the laser beams define the relative positions of the holding spaces, and therefore the relative positions of the source elements, and determine their movement between interaction positions along the laser beam. For example, in one embodiment of the source device, the inter-plane distance between the holding plane in the first holding position and the holding plane in the second holding position, and the source distance between two holding spaces within the holding plane, depend on the angle of incidence. Therefore, providing the same angle of incidence for all laser beams can simplify the boundary conditions when designing a source device for a particular TLE system. In the exemplary embodiment of the source device mentioned in this paragraph, equal values ​​can be selected for the source distance and inter-plane distance for all pairs of holding spaces available for the laser beams.

[0042] The TLE system according to the present invention can be further improved by configuring the holding structure of the source device to have three or more holding spaces, which form a regular holding polygon, and the laser light source to provide the one or more laser beams aligned with the sides of the holding polygon. In this embodiment, not only are all the laser beams incident at the same angle, but the source distance between pairs of holding spaces, i.e., the source distance between the vertices of the holding polygon, is also equal. Therefore, the same interplanar distance can be selected for all pairs of holding spaces. Moving the holding structure forming the holding polygon from its first holding position to its second holding position changes the active interaction position for all laser beams from the first interaction position to the second interaction position. This allows for quick and easy changes in the composition of the evaporated and / or sublimated raw material. Furthermore, aligning the laser beams with the sides of the holding polygon can avoid interference between the laser beams, including those reflected after being irradiated by the source elements, and the elements of the source device or the substrate.

[0043] According to another improved embodiment of the TLE system of the present invention, the TLE system includes one or more sensor devices for monitoring the one or more source elements, the central axis of the field of view of the one or more sensor devices being arranged to intersect one of the holding spaces when the holding structure is in its first holding position and when it is in its second holding position. In other words, only a single sensor device is required to monitor two different evaporation and / or sublimation processes when the holding structure is in both its first and second holding positions. Therefore, the number of sensor devices required to monitor all possible evaporation and / or sublimation processes can be significantly reduced, in particular by half. This simplifies the configuration of the TLE system of the present invention.

[0044] The TLE system of the present invention can be further improved by incorporating a camera and / or pyrometer as the sensor device. A camera can be used to identify the three-dimensional surface structure present on the source element during the evaporation and / or sublimation process, thereby providing information about whether the evaporation and / or sublimation process is occurring within desired parameters. Furthermore, the brightness of the camera image of the emitting source, especially when calibrated with accurate f-stop and exposure time values, provides an indication of the source temperature. A pyrometer can be used to more accurately measure the temperature of each source element. This information can then be used to monitor each source element during the evaporation and / or sublimation process.

[0045] According to another embodiment, the TLE system of the present invention can be further improved by aligning the laser beam and the central axis of the sensor device, which are directed toward the same holding space when the holding structure is in its first holding position, with each other so that the laser beam intersects a different holding space from the central axis of the sensor device when the holding structure is in its second holding position. In other words, when the holding structure is in its first holding position, the laser beam and the central axis of the sensor device intersect at each holding space, but when the holding structure is in its second holding position, they point in different directions so as to be directed toward different holding spaces. This makes it possible to avoid interference between the laser beam, including the laser beam reflected after being irradiated by each source element, and the sensor device.

[0046] The present invention will be described in detail below based on embodiments and with reference to the drawings. In particular, the drawings are as follows: [Brief explanation of the drawings]

[0047] [Figure 1] 1 shows a source device according to the invention in three schematic views. [Figure 2] 1 is a schematic diagram of a TLE system according to the present invention; [Figure 3]FIG. 1 is a schematic diagram of a source device having two laser beams. [Figure 4] 1 is a schematic diagram of a source device with possible central axes of the laser beam and the sensor device; [Figure 5] 1 shows possible alternative embodiments of the source device in three schematic diagrams. [Figure 6] 10 shows yet another possible embodiment of a source device in three schematic diagrams. DETAILED DESCRIPTION OF THE INVENTION

[0048] Figure 1 shows three schematic diagrams of possible embodiments of a source device 10 according to the present invention, where Figure 1A shows the holding structure 22 and laser beam 130 of the source device 10 at a first holding position 40, Figure 1B shows the same holding structure 22 and the same laser beam 130 at a second holding position 42, and Figure 1C shows a superposition of Figures 1A and 1B.

[0049] The source device 10 shown in Figure 1 includes a holding device 20 including a holding structure 22 having five holding spaces 24. All holding spaces 24 are provided with source elements 120 of a TLE system 100 (see Figure 2). One of the source elements 120 is irradiated with a laser beam 130 of the TLE system 100, which vaporizes and / or sublimes raw material supplied from each source element 120. The average direction 122 of the evaporated and / or sublimated raw material is indicated by an arrow and is approximately perpendicular to the surface of the source element 120.

[0050] Five holding spaces 24 are arranged on a holding plane 28 to form a regular holding polygon 30. In other words, the source distance 50 (see FIGS. 1A and 1B) between pairs of holding spaces 26 of the holding spaces 24 that make up the holding polygon 30 is equal for all pairs of holding spaces 26. For clarity, only one pair of holding spaces 26 is shown in each of FIGS. 1A and 1B.

[0051] 1A, the holding structure 22 is positioned at a first holding position 40. A laser beam 130 is irradiated onto a first interaction position 134 of a particular source element 120 positioned in one of the holding spaces 24, causing each raw material to evaporate and / or sublimate. The laser beam 130 is irradiated onto the surface of each source element 120 at an incident angle 132 of 45°.

[0052] 1B, the holding structure 22 is positioned at the second holding position 42. To move the holding structure 22, the source apparatus 10 includes an actuator 32 (see FIG. 2) mechanically coupled to the holding structure 22. In the embodiment of the source apparatus 10 according to the present invention shown in FIG. 1, the actuator 32 linearly moves the holding structure 22 between its first holding position 40 and second holding position 42.

[0053] When the holding structure 22 is in its second holding position 42, the same laser beam 130 is irradiated onto a second interaction position 136 of another source element 120 disposed in another holding space 24. In other words, by using the source device 10 according to the present invention in the TLE system 100, the same laser beam 130 can be used to evaporate and / or sublimate raw material supplied from the source element 120 at different positions within the reaction chamber 112, in particular at different substrate distances 54 (see FIG. 2 ) from the surface of the substrate 110.

[0054] 1A and 1B. As can be seen, the same laser beam 130 is used to evaporate and / or sublimate source material regardless of whether holding structure 22 is in its first holding position 40 or second holding position 42. Furthermore, it can be seen that the path of incident laser beam 130 as well as the path of reflected laser beam 138 are not blocked by any element of source apparatus 10 according to the present invention.

[0055] FIG. 2 shows a highly simplified side view of a TLE system 100 according to the present invention. A source device 10 and a substrate 110 according to the present invention are disposed within a reaction chamber 112 of the TLE system 100. The source device 10 is shown with the holding structure 22 of the holding device 20 in its first holding position 40 (solid lines) and its second holding position 42 (dashed lines). The holding structure 22 is separated by a planar distance 52 at the first holding position 40 and the second holding position 42, resulting in different substrate distances 54 between the substrate 110 and the holding structure at each of the holding positions 40 and 42. Furthermore, the laser beam 130 is shown in solid lines up to a first interaction position 134 and then in dashed lines up to a second interaction position 136. Linear movement of the holding structure 22 between the holding positions 40 and 42 is provided by an actuator 32 mechanically coupled to the holding structure 22 of the holding device 20. Additionally, the actuator 32 can also provide rotational motion to rotate the holding structure 22 about an axis 34. Preferably, the axis 34, and likewise the direction of linear motion of the holding structure 22 provided by the actuator 32, is aligned parallel to the average direction 122 of raw material evaporated and / or sublimated from the respective source elements 120 (not shown in FIG. 2, see e.g., FIG. 1).

[0056] Figure 3 shows source apparatus 10 in a similar representation to Figure 1C. Therefore, for details of source apparatus 10, please refer to the above description. However, unlike Figure 1, Figure 3 shows two laser beams 130 irradiating different source elements 120, and holding structure 22 is located at first holding position 40 and second holding position 42, respectively. This allows two raw materials to be evaporated and / or sublimated simultaneously, and the evaporated and / or sublimated raw materials can be combined and used as a base material for coating substrate 110 (see Figure 2).

[0057] However, by using the source device 10 according to the present invention, the source element 120 actually used for evaporation and / or sublimation can be easily, particularly quickly and conveniently, changed by moving the holding structure from its first holding position 40 to its second holding position 42, or from its second holding position 42 to its first holding position 40. This makes it possible to provide a layer structure for coating the substrate 110, with different materials for each layer.

[0058] FIG. 4 also shows the source device 10 in a similar representation to FIG. 1C . Therefore, for details of the source device 10, please refer again to the above description. However, in addition to the content of FIG. 1 , FIG. 4 also shows two possible central axes 142 of the sensor devices 140 (also represented by lines indicating each central axis 142). These sensor devices 140 may be, for example, cameras and / or pyrometers. Preferably, when the holding structure 22 is in its first holding position 40, the laser beam 130 and the central axis 142 of each sensor device 140 can be directed toward the same holding space 24. This makes it possible to monitor the evaporation and / or sublimation of each source element 120. However, when the holding structure 22 is in its second holding position 42, the laser beam 130 and the central axis 142 are aligned with each other so that the laser beam 130 intersects a different holding space 24 than the central axis 142 of the sensor device 140. This makes it possible to avoid harmful interference between the laser beam 130 and the sensor device 140. It should be noted that the central axis 142 of the sensor device 140 is not positioned along the side of the holding polygon 30, because interference with the irradiated laser beam 130 (not shown in FIG. 4) cannot be avoided, or at least eliminated.

[0059] As mentioned above, actuator 32 (see FIG. 2) can be mechanically coupled to holding structure 22 to allow rotation of holding structure 22. This allows, for example, changing the source element 120 being used without moving holding structure 22 between holding positions 40, 42.

[0060] However, Figures 5 and 6 illustrate another effect that the rotation enables. Both Figures 5 and 6 show the holding structure 22 with six holding spaces 24 (only some of which are indicated by reference symbols for clarity) arranged in a regular holding polygon 30. In Figures 5 and 6, Figures 5A and 6A show isometric views, Figures 5B and 6B show top views, and Figures 5C and 6C show side views, each showing the holding structure 22 positioned in both holding positions 40 and 42, along with the laser beam 130.

[0061] In contrast to Figure 1, in which the holding structure 22 only moves linearly between the holding positions 40, 42, in Figure 5, this linear movement is further superimposed with a rotation having a planar rotation angle 56 of 40° (see Figure 5B). The same superimposed movement is also present in Figure 6, but the planar rotation angle 56 is 80° (see Figure 6B). Each axis 34 (see Figures 5C and 6C) is centered and perpendicular to the holding polygon 30 in both cases. In both cases, this rotation allows the same holding space 24, and therefore the same source element 120, to be used, regardless of the actual holding positions 40, 42 of the holding structure 22.

[0062] 5C and 6C, the effect of the superimposed rotation can be clearly seen. The inter-planar distance 54 when the holding structure 22 is in each of the holding positions 40 and 42 varies depending on each of the planar rotation angles 56. In summary, by appropriately selecting the planar rotation angle 56, the inter-planar distance 52 can be adjusted. [Explanation of symbols]

[0063] 10...Source device 20...Holding device 22...Holding structure 24...holding space 26... Retention space pair 28…Holding plane 30...Retention polygon 32...Actuator 34...Axis 40...First holding position 42...Second holding position 50...Source distance 52…Distance between planes 54...Substrate distance 56...Plane rotation angle 100...TLE system 110...Substrate 112...Reaction chamber 120...Source element 122…Average direction 130...Laser beam 132...Angle of incidence 134...first interaction position 136...second interaction position 138...Reflected laser beam 140...Sensor device 142...Central axis

Claims

1. A source device (10) for a thermal laser epitaxy (TLE) system (100), comprising: a holding device (20) including a movable holding structure (22) having one or more holding spaces (24) for arranging one or more source elements (120) that supply raw materials to be evaporated and / or sublimated by a laser beam (130) of the TLE system (100) for coating a substrate (110) of the TLE system (100); an actuator (32) mechanically coupled to the holding structure (22); Equipped with the actuator (32) is configured to move the holding structure (22) between two or more holding positions; At a first holding position (40) of the two or more holding positions, one of the one or more source elements (120) disposed in each of the holding spaces (24) is positioned at a first interaction position (134) along the laser beam (130); At a second holding position (42) of the two or more holding positions, one of the one or more source elements (120) arranged in each holding space (24) is positioned at a second interaction position (136) along the laser beam (130) that is different from the first interaction position (134). A source device (10).

2. 2. A source device (10) according to claim 1, When the source device (10) is attached, the substrate distance (54) from the second holding position (42) to the substrate (110) is longer than the substrate distance (54) from the first holding position (40) to the substrate (110). A source device (10).

3. A source device (10) according to claim 1 or 2, The second interaction location (136) is downstream of the laser beam (130) relative to the first interaction location (134). A source device (10).

4. A source device (10) according to any one of claims 1 to 3, The actuator (32) is configured to linearly move the holding structure (22) and / or to rotate the holding structure (22). A source device (10).

5. A source device (10) according to claim 4, The linear motion of the holding structure (22) is parallel to the average direction (122) of the raw material evaporated and / or sublimated by irradiation with the laser beam (130) of each of the source elements (120). A source device (10).

6. A source device (10) according to claim 4 or 5, The axis of rotation of the holding structure is parallel to the average direction of evaporation and / or sublimation of the raw material of each source element disposed in each holding space by irradiation with the laser beam. A source device (10).

7. A source device (10) according to any one of claims 1 to 6, A first holding space (24) disposable at the first interaction position (134) along the laser beam (130) when the holding structure (22) is in the first holding position (40) is the same as a second holding space (24) disposable at the second interaction position (136) along the laser beam (130) when the holding structure (22) is in the second holding position (42). A source device (10).

8. A source device (10) according to any one of claims 1 to 7, A first holding space (24) disposable at the first interaction position (134) along the laser beam (130) when the holding structure (22) is in the first holding position (40) is different from a second holding space (24) disposable at the second interaction position (136) along the laser beam (130) when the holding structure (22) is in the second holding position (42). A source device (10).

9. A source device (10) according to claim 8, The first holding space (24) and the second holding space (24) are arranged on a holding plane (28) in the holding structure (22), and the holding plane (28) is perpendicular to the average direction (122) of the raw material evaporated and / or sublimated by irradiation with the laser beam (130) of each of the source elements (120) arranged in each of the holding spaces (24). A source device (10).

10. A source device (10) according to claim 9, The linear motion of the holding structure (22) provided by the actuator (32) is parallel to the average direction (122) of the raw material evaporated and / or sublimated by irradiation with the laser beam (130) of each of the source elements (120) arranged in each of the holding spaces (24), and a source distance (50) between the first holding space (24) and the second holding space (24) in the holding plane (28) and a planar distance (52) between the holding plane (28) having the first holding space (24) at the first interaction position (134) and the holding plane (28) having the second holding space (24) at the second interaction position (136) are selected according to an angle of incidence (132) of the laser beam (130) in the TLE system (100) irradiated onto surfaces of the source elements (120) that can be arranged in the first holding space (24) and the second holding space (24). A source device (10).

11. A source device (10) according to claim 10, The source distance (50) and the plane-to-plane distance (52) are selected such that the value of the plane-to-plane distance (52) divided by the value of the source distance (50) is tangent to the angle of incidence (132). A source device (10).

12. A source device (10) according to claim 10 or 11, The source device (10) is configured for use in a TLE system (100) having at least a first laser beam (130) and a second laser beam (130), and thus includes at least two pairs of holding spaces (26) consisting of a first holding space (24) and a second holding space, and the respective source distances (50) between the first holding space (24) and the second holding space (24) in each pair of holding spaces (26) are selected according to the angle of incidence (132) of the respective laser beams (130) and the common plane distance (52). A source device (10).

13. A source device (10) according to claim 12, The respective angles of incidence (132) of the respective laser beams (130) and therefore the respective source distances (50) of the respective holding space pairs (26) are different. A source device (10).

14. A source device (10) according to claim 12, The angles of incidence (132) of the laser beams (130) and therefore the source distances (50) of the holding space pairs (26) are equal. A source device (10).

15. A source device (10) according to claim 14, The retaining structure (22) includes three or more retaining spaces (24), and the three or more retaining spaces (24) form a regular retaining polygon (30). A source device (10).

16. 16. A source device (10) according to claim 15, The center of the retaining polygon (30) can be positioned facing the substrate (110) in the TLE system (100). A source device (10).

17. A source device (10) according to claim 15 or 16, The actuator (32) is configured to rotate the holding structure (22) about an axis (34) perpendicular to the center of the holding polygon (30). A source device (10).

18. 18. A source device (10) according to claim 17, The interplanar distance (52) is selected in response to the angle of incidence (132), the source distance (50), and the planar rotation angle (56) between the relative rotational positions of the holding structure (22) at the first holding position (40) and the second holding position (42). A source device (10).

19. 1. A thermal laser epitaxy (TLE) system (100) for coating a surface of a substrate (110) with a layer comprising one or more raw materials, comprising: a reaction chamber (112) enclosing a reaction volume that is sealable against the surrounding atmosphere; a gas system (100) for providing an adjustable reaction atmosphere within the reaction volume; a positioning means for positioning a substrate (110) within said reaction volume; a substrate heating means for heating the substrate (110); a laser system (100) for providing one or more laser beams (130) for vaporizing and / or sublimating the one or more raw materials; a source device (10) for supplying the one or more raw materials into the reaction chamber (112); Equipped with The source device (10) is configured according to any one of claims 1 to 18, wherein one or more source elements (120) for supplying the one or more raw materials are arranged in each holding space (24) of the source device (10). TLE system (100).

20. 20. The TLE system (100) of claim 19, comprising: The laser light source provides the one or more laser beams (130) with an angle of incidence (132) selected from the range of greater than 0° and less than 90°, in particular from the range of 30° to 60°, preferably an angle of incidence (132) of 45°. TLE system (100).

21. 21. A TLE system (100) according to claim 19 or 20, comprising: The laser source provides one or more laser beams (130) all having the same angle of incidence (132). TLE system (100).

22. 22. The TLE system (100) of claim 21, comprising: The holding structure (22) of the source device (10) has three or more holding spaces (24), the three or more holding spaces (24) forming a regular holding polygon (30), and the laser light source provides the one or more laser beams (130) aligned with the sides of the holding polygon (30). TLE system (100).

23. 23. The TLE system (100) of claim 22, comprising: The TLE system (100) includes one or more sensor devices (140) for monitoring the one or more source elements (120), and a central axis (142) of a field of view of the one or more sensor devices (140) is positioned to intersect one of the holding spaces (24) when the holding structure (22) is in the first holding position (40) and the second holding position (42). TLE system (100).

24. 24. The TLE system (100) of claim 23, comprising: The sensor device (140) is a camera and / or a pyrometer. TLE system (100).

25. 25. The TLE system (100) of claim 23 or 24, The laser beam (130) and the central axis (142) of the sensor device (140), which are directed toward the same holding space (24) when the holding structure (22) is in the first holding position (40), are aligned with each other such that the laser beam (130) intersects a different holding space (24) from the central axis (142) of the sensor device (140) when the holding structure (22) is in the second holding position (42). TLE system (100).

Images