Thermal laser evaporation system and method for supplying a thermal laser beam to a source.
The thermal laser evaporation system controls laser beam parameters outside the vacuum chamber, ensuring uniform evaporation and sublimation of diverse materials with high accuracy and reliability, addressing complexity and versatility issues in existing systems.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MAX PLANCK GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN EV
- Filing Date
- 2020-04-09
- Publication Date
- 2026-06-05
AI Technical Summary
Existing thermal laser evaporation systems require precise and collective movement of components inside and outside the vacuum chamber to control laser beam parameters, increasing complexity and reducing versatility and reliability.
A thermal laser evaporation system with a shaping device positioned between a collimating lens and a focusing lens outside the vacuum chamber, allowing for precise control of laser beam parameters such as position, shape, and size without affecting the alignment, enabling uniform evaporation and sublimation of various source materials, including non-rotationally symmetrical shapes.
The system provides high-accuracy, cost-effective control of laser beam parameters, allowing uniform illumination and evaporation of diverse materials, while maintaining system reliability and versatility by preserving optical alignment and preventing material deposition on chamber components.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a thermal laser evaporation system, which includes a laser light source for supplying a thermal laser beam to evaporate one or more materials from a source, a thermal laser beam shaping system having a collimating lens and a focusing lens for directing the thermal laser beam towards the source, a vacuum chamber, a vacuum window for transmitting the thermal laser beam into the vacuum chamber, and an aperture disposed between the vacuum window and the source in the vacuum chamber. Further, the present invention relates to a method for supplying a thermal laser beam to a source so as to evaporate one or more materials from the source. The method according to the present invention comprises a step of supplying a thermal laser beam, and directing the thermal laser beam towards a vacuum chamber having a vacuum window for transmitting the thermal laser beam into the vacuum chamber via a thermal laser beam shaping system having a collimating lens, a shaping device and a focusing lens, and directing the thermal laser beam at the source through an aperture disposed within the vacuum chamber.
Background Art
[0002] In a thermal laser evaporation system, the laser light is typically directed at a source material disposed within a vacuum chamber at a certain angle. In order to achieve a stable evaporation rate, the beam needs to be scanned across a larger source surface, or the size of the source, the power of the laser and the size of the beam need to be matched such that the average source material is evaporated uniformly across the upper surface of the source.
[0003] To satisfy this constraint, the size and / or position of the beam in the source may be varied by moving the laser beam along the beam propagation axis together with a beam protective aperture, with a constant focal length and flaring. To scan the beam across individual sources, the laser beam and protective aperture may be moved along two directions in the plane of the source, or in the plane of the protective aperture, with appropriate modifications.
[0004] However, this method is not very practical because it requires the precise and collective movement of components inside and outside the vacuum chamber, which increases complexity and reduces the overall reliability and versatility of the apparatus. This particularly affects the range of possible composite conditions and geometric shapes that can be used. [Overview of the Initiative] [Problems that the invention aims to solve]
[0005] In view of the above, an object of the present invention is to provide an improved thermal laser evaporation system and an improved method for providing a thermal laser beam in a source that do not have the aforementioned drawbacks of the prior art. In particular, an object of the present invention is to provide a thermal laser evaporation system and method that can control the parameters of a laser beam in a source with high accuracy in a particularly simple and cost-effective manner. [Means for solving the problem]
[0006] This objective is satisfied by each of the independent patent claims. In particular, this objective is satisfied by a thermal laser evaporation system according to claim 1 and by a method of supplying a thermal laser beam in a source according to claim 15. Dependent claims describe preferred embodiments of the present invention. Details and advantages described for a thermal laser evaporation system according to the first aspect of the present invention refer to a method of depositing a source material on a target material according to the second aspect of the present invention, and in technical sense, the reverse is also true.
[0007] According to the first aspect of the present invention, the objective is satisfied by a thermal laser evaporation system, which thermal laser evaporation system A laser light source that supplies a thermal laser beam to vaporize one or more materials from a source, A thermal laser beam shaping system having a collimating lens and a focusing lens for directing a thermal laser beam to a source, Vacuum chamber and A vacuum window that transmits a thermal laser beam into a vacuum chamber, An aperture positioned between the vacuum window and the source within the vacuum chamber, It is equipped with, The thermal laser beam shaping system has a shaping device positioned between a collimating lens and a focusing lens to adapt at least one of the position, shape, and size of the thermal laser beam in the source.
[0008] A thermal laser evaporation system according to the present invention can be used for the thermal evaporation and / or sublimation of one or more source materials, particularly deposits on a target material. A wide variety of source materials, especially metals and other solids, are possible. However, liquid and gaseous source materials can also be used with special source holders. Sources, arranged in a suitable source holder and / or configured in a self-supporting manner, are placed in a vacuum chamber.
[0009] According to the present invention, the vacuum chamber is, for example, 10 -11 A vacuum as low as millibars, and / or 10 -11 It can be used to include any suitable reaction atmosphere having a pressure between millibars and 1 millibar. This reaction atmosphere may include, for example, molecular oxygen, ozone, molecular nitrogen, or other reaction gases.
[0010] An external laser light source supplies a thermal laser beam. The laser light forming the laser beam can preferably be supplied over a wide energy range, from infrared to ultraviolet. In particular, appropriately adapted laser light can be selected for different source materials.
[0011] According to the present invention, the thermal laser is particularly adapted to evaporate and / or sublimate the source material by continuously or at least essentially continuously striking the source at an angle between 0° and 90°, preferably between 30° and 90°, and heating the source with laser energy lower than the energy required to generate plasma.
[0012] The laser beam enters the vacuum chamber through the vacuum window, and then, along its path through the vacuum chamber, penetrates the aperture before colliding with the source. Preferably, the aperture extends perpendicular to the optical axis of the thermal laser beam. This protects the vacuum window from deposits of evaporated and / or sublimated source material.
[0013] In many cases, a laser source supplies thermal laser light as a beam that is at least partially flared, especially when the last element of the laser source is an optical fiber. In particular, the thermal laser beam shaping system for a thermal evaporation system according to the present invention provides compensation for the aforementioned flaring of the laser beam supplied by the laser source. As basic elements, the laser beam shaping system comprises a collimating lens and a focusing lens.
[0014] The collimating lens preferably directs the flared laser beam supplied by the laser source into a parallel or at least essentially parallel laser beam. In many embodiments of the laser beam shaping system, the collimating lens forms the first element of the laser beam shaping system along the laser beam. A focusing lens is positioned at the other end of the laser beam shaping system. The focusing lens receives the parallel or at least essentially parallel laser beam and directs it toward the target. Preferably, the focal volume, to which the laser beam reaches its minimum extent, is positioned in a vacuum chamber between the vacuum window and the source. Additionally and equally preferably, apertures can be positioned on and around this focal volume.
[0015] For this invention, it is essential that a shaping device be positioned between the collimating lens and the focusing lens in order to externally modify the parameters of the laser beam in a source located within a vacuum chamber. The shaping device, having elements that modify at least one of the position, shape, and size of the laser beam and, consequently, the thermal laser beam in the source, can be influenced and adapted. In other words, a wide range of parameters of the laser beam that actually strikes the source can be adapted.
[0016] By changing the parameters of the thermal laser beam in the source, such as its position, the arrangement on the source in which evaporation and / or sublimation occurs can be selected, and in particular actively selected.
[0017] By adapting the shape of the laser beam, distortions caused by the projection of the incoming laser beam onto the source can be compensated for. Furthermore, any shape of source, especially non-rotationally symmetrical shapes, can be uniformly illuminated. In addition, non-uniform illumination of the source surface is possible, for example, to compensate for uneven heat dissipation and / or for sources having areas containing different materials.
[0018] The size of the laser beam, particularly its compression and / or expansion, affects the spatial energy density of the laser in the source. This allows for adaptation for different source materials, for example, those with different melting and evaporation temperatures.
[0019] Since the shaping device is positioned in a section of the laser beam where the laser beam is preferably parallel or at least essentially parallel, this adaptation can be provided in a particularly concise manner.
[0020] Furthermore, the thermal laser beam shaping system is positioned entirely outside the vacuum chamber. For example, the influence of the beam shaping system on the reaction atmosphere inside the vacuum chamber, caused by beam shaping and especially by the movable elements of the shaping apparatus, can be prevented. Also, the deposition of evaporated and / or sublimated material of the source onto the components of the laser beam shaping system is impossible.
[0021] Furthermore, a thermal laser evaporation system according to the present invention can be characterized in that the shaping device preserves the parallel or at least essentially parallel alignment of the thermal laser beam after the collimating lens. In this preferred embodiment of the laser evaporation system according to the present invention, the collimating lens and the focusing lens are configured to be adapted to one another such that the collimating lens transitions the flared laser beam supplied by the laser light source into a parallel laser beam. Subsequently, the focusing lens receives the parallel laser beam and directs this laser light toward a target.
[0022] For optical properties, as long as the light impinges on the focusing lens in a parallel beam, the focusing lens directs all the incoming light towards the target. Thus, by the shaping device preserving the parallel or at least essentially parallel alignment of the thermal laser beam after the collimating lens, the adaptation and / or modification of the laser beam supplied by the shaping device do not affect the directing functionality of the focusing lens. In other words, the laser light beam adapted by the shaping device is directed towards the source by the focusing lens without the need for additional compensation. In particular, the focal volume where the focusing lens focuses the laser beam remains stationary at the same location within the vacuum chamber. Preferably, the aperture can be positioned with its aperture opening at this focal volume, and thus the aperture can remain stationary independently of the adjustment of the laser beam supplied by the shaping device.
[0023] Furthermore, a thermal laser evaporation system according to the present invention can include that the collimating lens and the focusing lens are stationary within the laser beam shaping system, particularly within the thermal laser evaporation system, with respect to the source and the laser light source. In other words, the outer end of the laser beam shaping device remains fixed independently of the state of the shaping device within the laser beam shaping system. Thereby, for example, the laser beam shaping device can be arranged and fixed with respect to the vacuum chamber and / or the laser light source. In particular, even if the laser light beam is modified by the laser beam shaping system, the optical alignment of the entire thermal laser evaporation system can be preserved.
[0024] In additional embodiments, a thermal laser evaporation system according to the present invention can be characterized in that the shaping device has at least some of the following components, which are selected from the group of elements consisting of one or more mirrors, one or more beam compressors, one or more beam expanders, one or more beam splitters, one or more lenses, one or more prisms, and combinations thereof. This list is not exhaustive, and thus other suitable optical components can be used as parts of the shaping device. In summary, a wide variety of laser beams with variable properties can be provided by the shaping device by selecting appropriate optical components.
[0025] Furthermore, a thermal laser evaporation system according to the present invention can include that the shaping device has one of the following shape conforming elements that conform the shape of the thermal laser beam.
[0026] Anamorphic prism pair Combination of cylindrical lenses Beam cutting element Freeform mirror This list is not exhaustive, and thus other suitable shape conforming elements can be used as parts of the shaping device. The shape conforming elements can actively change the shape of the laser beam. For example, the beam cutting element can block a portion of the laser beam. The other optical elements described in the list actually deform the laser beam, for example, to change a laser beam having a circular cross-section to a laser beam having an elliptical cross-section. The freeform mirror can be used to replace any of the described optical elements such as a prism or a lens.
[0027] Additionally or alternatively, a thermal laser evaporation system according to the present invention can be characterized in that the shaping device has one of the following size conforming elements that conform the size of the thermal laser beam.
[0028] Defocus lenses and harmonized focus lenses Focusing lenses and harmonized defocusing lenses Beam cutting element Beam compressor Beam expander Freeform Mirror This list is not exhaustive, and for this reason, other suitable size-adjusting elements can be used as components of shaping devices. Size-adjusting elements can actively change the size of a laser beam, particularly the size of the cross-section of the laser beam perpendicular to the optical axis of the laser beam. For example, beam cutting elements can cut off a portion of the laser beam and thus reduce the size of the laser beam. Pairs of defocusing and focusing lenses, as well as beam compressors and beam expanders, can enlarge or reduce the size of the cross-section of the laser beam based on their order along the laser beam. Again, free-form mirrors can be used to replace any of the described optical elements such as prisms or lenses.
[0029] According to an additional or alternative embodiment of a thermal laser evaporation system according to the present invention, the shaping apparatus has one of the following position-adjusting elements that adapts the position of the thermal laser beam in the source.
[0030] prism Mirrors, especially free-form mirrors. Diffractive optical elements Beam extraction element This list is not exhaustive, and for this reason, other suitable position-adjusting elements can be used as components of the shaping device. These position-adjusting elements allow for the active alteration of the position of the laser beam, particularly the position of the laser beam perpendicular to the optical axis, in front of the position-adjusting element. Cutting elements cut off a portion of the laser beam and thus change the center of gravity of the remaining laser beam. Other optical elements can actively alter the position of the laser beam without energy loss of the laser beam and thus provide position adjustment.
[0031] Furthermore, the thermal laser evaporation system can be improved by having a drive mechanism that moves at least one position-adjusting element to scan the source by adapting the position of the thermal laser beam in the source. By moving at least one position-adjusting element, the position of the laser beam in the source is moved accordingly. In other words, the surface of the source can be scanned by the position of the thermal laser beam supplied by the laser beam-adjusting system. A particularly uniform time-averaged distribution of the energy of the thermal laser beam across the entire surface of the source, and consequently a particularly uniform temperature distribution within the source near the illuminated surface of the source, can be provided.
[0032] Furthermore, the thermal laser evaporation system according to the present invention further comprises a thermal laser beam shaping system which includes a splitting device that splits a thermal laser beam coming from a laser source into two or more partial laser beams, the shaping device being configured to conform at least one of the positions, shapes and sizes of the two or more partial laser beams. In other words, after passing through the laser beam shaping system, two or more individual laser beams are supplied and can be used to evaporate and / or sublimate a source material at two or more corresponding positions.
[0033] In particular, at these two or more locations, different sources can be arranged to allow simultaneous evaporation and / or sublimation of two or more different source materials. Since the shaping apparatus can adapt at least one of the positions, shapes and sizes of two or more partial laser beams, all the advantages provided by the shaping apparatus described above can be provided to each of the partial laser beams. Preferably, within the laser beam shaping system, a splitting device is positioned in front of the shaping apparatus along the laser beam.
[0034] In an improved embodiment of the thermal laser evaporation system according to the present invention, the splitting device includes one of the following splitting elements that splits a thermal laser beam coming from a laser light source into two or more partial laser beams.
[0035] Mirrors, especially free-form mirrors. prism aperture This list is not exhaustive, and therefore other suitable splitting elements can be used as components of the splitting device. Preferably, this splitting element and thus the splitting device as a whole preserve the parallel alignment of the laser beam after the collimating lens. Thus, each of the two or more partial laser beams is processed by a shaping device similar to the unsplit laser beam supplied by the laser source.
[0036] Preferably, the thermal laser evaporation system according to the present invention is improved by the shaping device being configured to adapt two or more laser beams differently to at least one of the position, shape, and size of two or more partial laser beams. In other words, each of the two or more partial laser beams can be modified independently of the remaining partial laser beams with respect to position and / or shape and / or size. Thus, flexibility with respect to the parameters of the supplied partial laser beams can be improved.
[0037] Furthermore, in the thermal laser evaporation system according to the present invention, the thermal laser beam collides with the source at an angle between 30° and 60°, particularly at 45°, so that the elliptical beam point, adjusted by a laser beam shaping system directed to the source, generates a circular beam point on the source. The preferred collision angle of 45° makes it possible to provide sufficient placement space for both the source and the target. However, a circular laser beam collides with the source at an angle, preferably about 45°, creates an elliptical footprint of the laser beam on the source. This can be compensated for by providing an elliptical beam point perpendicular to the optical axis of the laser beam, and a circular beam point can be provided in the source arrangement. This is particularly advantageous for a source having a circular cross-section, as it can result in complete and uniform illumination of the source.
[0038] According to another embodiment of the thermal laser evaporation system according to the present invention, the collimating lens and / or the focusing lens are incorporated into the shaping device, in particular, the collimating lens forming the upstream end of the shaping device and / or the focusing lens forming the downstream end of the shaping device. Thus, a particularly compact embodiment of the laser beam shaping system can be provided.
[0039] Furthermore, in the thermal laser evaporation system according to the present invention, the focusing lens focuses the thermal laser beam on a point-like focal volume positioned between the vacuum window and the source in the vacuum chamber, and the aperture has an aperture opening and is positioned in the vacuum volume with the aperture opening of the aperture to protect the vacuum window from particles evaporated from the source.
[0040] The point focal volume represents the minimum range of the laser beam. By positioning an aperture with an aperture opening around this focal volume, optimized protection of the vacuum window against deposits of evaporated and / or sublimated source material can be achieved. In particular, in other embodiments, the aperture opening is even formed by directing a laser beam with a point focal volume towards the aperture. Thus, particularly precise alignment of the laser beam and aperture can be achieved.
[0041] According to a second aspect of the present invention, the objective is satisfied by a method of supplying a thermal laser beam in a source so as to evaporate one or more materials from the source, and this method is The steps include supplying a thermal laser beam, The process includes the steps of directing a thermal laser beam to a vacuum chamber having a vacuum window that transmits the thermal laser beam to a vacuum chamber via a thermal laser beam shaping system having a collimating lens, a shaping device and a focusing lens, and directing the thermal laser beam at a source through an aperture located within the vacuum chamber, wherein the step of directing the thermal laser beam by the thermal laser beam shaping system has at least one configuration of the position, shape and size of the thermal laser beam at the source by the shaping device.
[0042] The method according to the present invention can be carried out in a thermal laser evaporation system, in particular, to evaporate and / or sublimate at least one material of a source placed in the vacuum chamber of the thermal laser evaporation system.
[0043] In the first step of the method according to the present invention, the thermal laser beam is preferably supplied by a laser light source. For example, the laser light source may have an optical fiber that guides the laser light near the vacuum chamber.
[0044] In the following steps of the method according to the present invention, a laser beam is directed towards a vacuum chamber and then towards a source. For this purpose, the vacuum chamber has a vacuum window. An aperture is positioned within the vacuum chamber and between the vacuum window and the source to protect the vacuum window from material evaporated and / or sublimated from the source.
[0045] In particular, outside the vacuum chamber, a laser beam shaping system is positioned to transmit the thermal laser beam into the vacuum chamber through a vacuum window. This laser beam shaping system first has a collimating lens that compensates for the flaring of the thermal laser beam supplied by the laser light source, for example, after it exits the optical fiber mentioned above. At the opposite end, the laser beam shaping system has a focusing lens that projects and directs the thermal laser beam, focusing it towards the source through the vacuum window and aperture.
[0046] A shaping device is positioned between the collimating lens and the focusing lens. When the method of the present invention is being carried out, this shaping device provides at least one configuration of the position, shape, and size of the thermal laser beam in the source.
[0047] By changing the position of the thermal laser beam in the source, an arrangement on the source that causes evaporation and / or sublimation can be selected, and in particular, actively selected. By adapting the shape of the laser beam, distortion caused by the projection of the laser beam impacting the source can be compensated for. Furthermore, any shape of source, especially a non-rotationally symmetric shape, can be illuminated uniformly.
[0048] The size of the laser beam, particularly its compression and / or expansion, affects the spatial energy density of the laser at the source. This allows for the matching of different source materials, for example, with different melting and evaporation temperatures. In other words, by performing the method according to the present invention, key parameters of the laser beam at the target can be addressed and actively matched.
[0049] Preferably, a method according to the present invention can be improved by the method being carried out by a thermal laser evaporation system according to a first aspect of the present invention. Thus, all the features and advantages described above for a thermal laser evaporation system according to a first aspect of the present invention can be provided by a method according to a second aspect of the present invention carried out by a system according to a first aspect of the present invention.
[0050] Furthermore, the method according to the present invention can be characterized in that, after the collimating lens, a parallel or at least essentially parallel alignment of the thermal laser beam is preserved by a shaping device. In this preferred embodiment of the method according to the present invention, a collimating lens is used to transition an incoming, flared laser beam supplied by a laser light source into a parallel laser beam, and subsequently, a focusing lens is used to direct this parallel laser beam toward a target.
[0051] Due to its optical properties, as long as the light strikes the focusing lens as a parallel beam, the focusing lens directs all incoming light toward the target. In particular, the focal volume in which the focusing lens focuses the laser beam remains stationary in the same location within the vacuum chamber. Preferably, an aperture can be positioned in this focal volume with its aperture opening, and thus the aperture can remain stationary independently of the adjustment of the laser beam supplied by the shaping device.
[0052] Therefore, by preserving the parallel or at least essentially parallel alignment of the thermal laser beam after the collimating lens through the shaping device, the fitting and / or modification of the laser beam supplied by the shaping device does not affect the directional functionality of the focusing lens, in particular, the position and / or size of the focal volume from which the focusing lens focuses the laser beam. In other words, the laser beam fitted by the shaping device is directed towards the source by the focusing lens without the need for additional compensation.
[0053] Furthermore, methods according to the present invention may include conforming the shape of a thermal laser beam by cutting out a portion of the thermal laser beam and / or by using a combination of an anamorphic prism pair and / or a cylindrical recal lens and / or a free-form mirror to change the shape of the thermal laser beam. By cutting out or actively changing the shape of the thermal laser beam, the region on the source that will be impacted by the thermal laser beam can be defined. Thus, it is possible to conform the shape of the impacting laser beam to the shape of the source and / or to intentionally illuminate only a portion of the source.
[0054] Preferably, the method according to the present invention can be improved by deforming a thermal laser beam supplied by a laser source having a circular cross-section into a thermal laser beam having an elliptical cross-section. In this particular embodiment of the method according to the present invention, a source having a circular cross-section can be illuminated particularly completely by a thermal laser beam striking the source at an angle, for example, 45°. In other words, the elliptical shape of the striking laser beam can be selected such that, after striking the source, the circular cross-section of the source is harmonized.
[0055] Furthermore, the method according to the present invention can be characterized in that the size of the thermal laser beam is adapted by cutting out a portion of the thermal laser beam and / or by using a harmonized pair of defocusing and focusing lenses and / or a beam compressor and / or beam expander and / or free-form mirror. By actively adapting and / or changing the size of the laser beam, the area of the source illuminated by the laser beam can be adapted.
[0056] In particular, the intense illumination of the source by the colliding laser beams is inhibited. Furthermore, the size of the laser beam can be selected so that the laser beam illuminates only a portion of the source. The energy density of the laser beam can be adjusted, especially when the laser beam is compressed or expanded to change its size.
[0057] In other embodiments, methods according to the present invention may include adapting the position of a thermal laser beam by cutting out a portion of the thermal laser beam and / or, in particular, by using position-adjusting elements, especially mirrors and / or prisms and / or diffractive optical elements, to change the position of the thermal laser beam in a beam shaping system with respect to the optical axis of the thermal laser beam supplied by a laser light source.
[0058] By changing the position of the thermal laser beam, it is possible to actively select the portion of the source to be illuminated. For example, a source can be divided internally into four quadrants, each containing a different source material. In this example, actively changing the position of the thermal laser beam provides the possibility of selecting the source material to be evaporated and / or sublimated. Additionally or alternatively, a source of a single material can be illuminated at different positions, for example, to prevent uneven wear of the source.
[0059] According to a preferred embodiment of the method according to the present invention, positioning a thermal laser beam involves scanning the source by moving at least one of the positioning elements with a drive unit of the thermal laser beam shaping system. Scanning the surface region of the source spreads the energy stored in the source. Thus, localized over-consumption of the source is prevented. By moving at least one of the positioning elements, this scanning can be provided particularly easily.
[0060] Furthermore, the method according to the present invention can be characterized in that the step of directing a thermal laser beam by a thermal laser beam shaping system includes splitting the thermal laser beam coming from the laser source into two or more partial laser beams by a splitting device of the thermal laser beam shaping system. This splitting allows the same laser source to be used to illuminate two or more different locations of the source simultaneously, where different materials can be placed. Preferably, the shaping device adapts at least one of the positions, shapes and sizes of two or more partial laser beams that are particularly independent of each other.
[0061] Furthermore, in another embodiment of the method according to the present invention, the thermal laser beam shaping system focuses a thermal laser beam to a point focal volume located between a vacuum window and a source in a vacuum chamber, where an aperture is positioned with an aperture opening in the focal volume to protect the vacuum window from particles evaporated from the source.
[0062] The point focal volume represents the minimum range of the laser beam. By positioning this focal volume between the source and the vacuum window, it is possible to prevent the thermal laser beam from unintentionally focusing on the wall of the vacuum chamber when it is out of the source. Furthermore, by positioning an aperture with an aperture opening around this focal volume, optimal protection of the vacuum window against deposits of evaporated and / or sublimated source material can be provided. In particular, in other embodiments, the aperture opening is even formed by directing a laser beam with a point focal volume towards the aperture. Thus, particularly precise alignment of the laser beam and aperture can be achieved.
[0063] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings. [Brief explanation of the drawing]
[0064] [Figure 1]This figure shows a thermal laser evaporation system according to the present invention, which has a thermal laser beam shaping system for changing the size of the laser beam. [Figure 2] This figure shows a thermal laser evaporation system according to the present invention, which has a thermal laser beam shaping system for changing the position of the laser beam. [Figure 3] This figure shows a thermal laser evaporation system according to the present invention, which has a thermal laser beam shaping system that changes the size and shape of the laser beam. [Figure 4] This figure shows a thermal laser evaporation system according to the present invention, which has a thermal laser beam shaping system that splits the laser beam into two partial laser beams. [Modes for carrying out the invention]
[0065] Figures 1 to 4 all illustrate different embodiments of the thermal laser evaporation system according to the present invention. Therefore, common components of the laser evaporation systems depicted in Figures 1 to 4 will be described together below, thereby highlighting the differences between the embodiments.
[0066] The depicted thermal laser evaporation system 10 has a laser light source 30, which in all embodiments shows the termination of the optical fiber 32. The laser beam 34 is directed by a laser beam shaping system 40 towards a source 20 located in a vacuum chamber 12.
[0067] Source 20 provides material 22 to be evaporated and / or sublimated by the impacting laser beam 34. The laser beam 34 enters the vacuum chamber 12 through the vacuum window 14.
[0068] The laser beam shaping system 40 focuses the laser beam 34 onto a point focal volume located between the vacuum window 14 and the source 20 within the vacuum chamber 12. An aperture 16 is positioned on and around the focal volume, so that the aperture opening 18 of the aperture is aligned with the point focal volume of the laser beam 34. The aperture protects the vacuum window 14 from deposits of evaporated and / or sublimated material 22 from the source 20.
[0069] The illustrated embodiment of the laser evaporation system 10 differs in its laser beam shaping system 40. Therefore, the laser beam shaping system 40 and its functionality will be described below.
[0070] All depicted laser beam shaping systems 40 share a collimating lens 42 at the upstream end 52 of the laser beam shaping system 40 and a focusing lens 44 at each downstream end 54 of the laser beam shaping system 40. In this regard, it should be noted that the upstream end 52 is positioned closest to the laser light source 40, and the downstream end 54 is positioned furthest from the laser light source 30.
[0071] At least an additional shaping device 60 (see Figures 1-3) or an additional splitting device (see Figure 4) is positioned between the collimating lens 42 and the focusing lens 44. In many cases, the laser beam 34 emanating from the optical fiber 32 is flared outwards. The collimating lens 42 is adapted to this convergence, shifting the incoming laser beam 34 into a parallel-aligned laser beam 34. The focusing lens 44 receives this parallel-aligned laser beam 34 and directs it toward the source 20, including focusing in particular toward the aforementioned point-like focal volume located within the vacuum chamber 12.
[0072] As depicted, the shaping device 60 and the splitting device 46 shown in Figure 4 preserve the parallel alignment of the laser beam 34. Therefore, the changes and adaptations of the laser beam 34 provided by the shaping device 60 and the splitting device 46 do not affect the general optical imaging characteristics of the laser beam shaping system 40 determined by the collimating lens 42 and the focusing lens 44. Furthermore, this allows these elements, namely the collimating lens 42 and the focusing lens 44, to be positioned stationary within the laser beam shaping system 40, particularly with respect to the ends and source 20 of the optical fiber 32.
[0073] Figure 1 shows an embodiment of a laser beam shaping system 40, in which a switchable size-adjusting element 64 forms the shaping apparatus 60 of the laser beam shaping system 40. This size-adjusting element 64 is, for example, a beam compressor, a beam expander, a free-form mirror, and / or a harmonized pair of defocus and focus lenses. In particular, in the state depicted on the left, the size-adjusting element 64 is deactivated, and there is essentially no change in the size of the laser beam 34. In contrast, on the right side of Figure 1, the size-adjusting element 64 is activated, and the laser beam 34 is compressed. This increases the spatial energy density of the laser beam 34 in the target 20, for example.
[0074] In this embodiment of the thermal laser evaporation system 10, the collimating lens 42 is additionally incorporated into the shaping device 60, as shown by the dashed line. Thus, a particularly compact device can be provided.
[0075] Furthermore, Figure 2 shows two embodiments of the thermal laser evaporation system 10 according to the present invention. In contrast to Figure 1, the shaping device 60 is configured as a position-adjusting element 66. This position-adjusting element 66 can be configured using, for example, a prism, a mirror, a diffractive optical element and / or a beam-cutting element.
[0076] As described above, the shaping device 60 does not affect the general optical imaging characteristics of the laser beam shaping device 40, which are determined by the collimating lens 42 and the focusing lens 44. Therefore, the change in the position of the laser beam 34 provided by the position adjustment element 66 is directed towards the source 20 by the focusing lens 44, creating different collision regions in the source 20.
[0077] Additionally, the drive unit 50 is mechanically connected to the position-adjusting elements 66 so as to cause movement of each position-adjusting element 66. This allows the collision area of the laser beam 34 on the target 20 to be actively changed and selected, in other words, the surface of the source 20 to be scanned within the laser beam 34.
[0078] Figure 3 shows a general possibility of combining several shaping devices 60, in this case a size-adjusting element 64 and a shape-adjusting element 62. Since each of the shaping devices 60 preserves the parallel alignment of the laser beam 34 between the collimating lens 42 and the focusing lens 44, a combination of two or more shaping devices 60 also provides this preservation functionality. The effect of the shape-adjusting element 62 is illustrated by showing the cross-section 38 of the laser beam 34, thereby changing the cross-section 38 of the laser beam 34 from circular to elliptical.
[0079] Figure 4 shows a splitting device 46 and its splitting element 48. In the splitting element 48, the laser beam 34 is split into two partial laser beams 36. Each partial laser beam 36 is independently directed to the source 20 by a focusing lens 44. A shaping device 60 (not shown) can also be used to change parameters, both individually and collectively, such as the size, shape, and / or position of the partial laser beams 36. [Explanation of Symbols]
[0080] 10 Laser evaporation systems 12 Vacuum Chamber 14 Vacuum window 16 Aperture 18 Aperture opening 20 Sources 22 Material 30 Laser light sources 32 optical fibers 34 laser beams 36 Partial laser beams 38 Cross-section 40 Laser beam shaping system 42 Collimating lenses 44-focus lens 46 Splitting device 48-segment element 50 Drive unit 52 Upstream end 54 Downstream end 60 Shaping device 62 Shape-matching elements 64 Size-compatible elements 66 Position-adjustable element
Claims
1. A laser light source (30) that supplies a thermal laser beam (34) to evaporate one or more materials (22) from a source (20), A thermal laser beam shaping system (40) having a collimating lens (42) and a focusing lens (44) that direct the thermal laser beam (34) to the source (20), Vacuum chamber (12) and A vacuum window (14) that transmits the thermal laser beam (34) to the vacuum chamber (12), In the vacuum chamber (12), an aperture (16) is positioned between the vacuum window (14) and the source (20), Equipped with, The thermal laser beam shaping system (40) includes a shaping device (60) positioned between the collimating lens (42) and the focusing lens (44) to adapt at least one of the position, shape, and size of the thermal laser beam (34) in the source (20), The collimating lens (42) and the focusing lens (44) are configured to be compatible with each other such that the collimating lens (42) converts the flared laser beam (34) supplied by the laser light source (30) into a parallel laser beam (34), and subsequently, the focusing lens (44) receives the parallel laser beam (34) and directs this laser beam (34) toward the source (20). The shaping device (60) preserves the parallel alignment of the thermal laser beam (34) after the collimating lens (42), and therefore the focal volume at which the focusing lens (44) focuses the laser beam (34) remains stationary in the same location within the vacuum chamber (12). A thermal laser evaporation system (10) characterized in that the collimating lens (42) and the focusing lens (44) are stationary within the thermal laser beam shaping system (40) relative to the source (20) and the laser light source (30).
2. The shaping apparatus (60) has at least some of the following components, the components being selected from the group of elements consisting of one or more mirrors, one or more beam compressors, one or more beam expanders, one or more beam dividers, one or more lenses, one or more prisms, and combinations thereof, as described in claim 1, the thermal laser evaporation system (10).
3. The thermal laser evaporation system (10) according to claim 1 or 2 is characterized in that the shaping device (60) has one of the following shape-adjusting elements (62) that adapt to the shape of the thermal laser beam (34), namely an anamorphic prism pair, a combination of cylindrical lenses, a beam cutting element, and a free-form mirror.
4. The shaping device (60) is characterized by having one of the following size-adjusting elements (64) that are suitable for the size of the thermal laser beam (34), namely a defocusing lens and harmonized focusing lens, a focusing lens and harmonized defocusing lens, a beam cutting element, a beam compressor, a beam expander, and a free-form mirror, as described in any one of claims 1 to 3.
5. The shaping device (60) is characterized by having one of the following position-adjusting elements (66) that adjust the position of the thermal laser beam (34) in the source (20), namely a prism, a mirror, a diffractive optical element, and a beam extraction element, as described in any one of claims 1 to 4.
6. The thermal laser evaporation system (10) according to claim 5 is characterized in that the thermal laser beam shaping system (40) comprises a drive device (50) that moves at least one of the position-adjusting elements (66) to scan the source (20) by adjusting the position of the thermal laser beam (34) in the source (20).
7. The thermal laser evaporation system (10) according to any one of claims 1 to 6, wherein the thermal laser beam shaping system (40) further comprises a splitting device (46) that splits the thermal laser beam (34) coming from the laser light source (30) into two or more partial laser beams (36), and the shaping device (60) is configured to conform at least one of the position, shape and size of the two or more partial laser beams (36).
8. The thermal laser evaporation system (10) according to claim 7, characterized in that the splitting device (46) has one of the following splitting elements (48), namely a mirror, a prism, and an aperture, which splits the thermal laser beam (34) coming from the laser light source (30) into two or more partial laser beams (36).
9. The thermal laser evaporation system (10) according to claim 7 or 8, characterized in that the shaping device (60) is configured to adapt the two or more partial laser beams (36) in a different manner with respect to at least one of the position, shape and size of the two or more partial laser beams (36).
10. The thermal laser evaporation system (10) according to any one of claims 1 to 9, characterized in that the thermal laser beam (34) collides with the source (20) at an angle between 30° and 60°, thereby generating a circular beam point on the source (20) from an elliptical beam point adjusted by the thermal laser beam shaping system (40) directed toward the source (20).
11. The thermal laser evaporation system (10) according to any one of claims 1 to 10, characterized in that the collimating lens (42) and / or the focusing lens (44) are incorporated into the shaping device (60).
12. The thermal laser evaporation system (10) according to any one of claims 1 to 11, characterized in that the focusing lens (44) focuses the thermal laser beam (34) to a point focal volume located between the vacuum window (12) and the source (20) in the vacuum chamber (12), and the aperture (16) has an aperture opening (18) and is positioned with the aperture opening (18) of the aperture in the focal volume to protect the vacuum window (12) from particles evaporated from the source (20).
13. A method of supplying a thermal laser beam (34) to a source (20) such that one or more materials (22) are evaporated from the source (20), The steps include supplying the thermal laser beam (34), The steps include: directing the thermal laser beam (34) to a vacuum chamber (12) having a vacuum window (12) that transmits the thermal laser beam (34) to the vacuum chamber (12) via a thermal laser beam shaping system (40) having a collimating lens (42), a shaping device (60), and a focusing lens (44); and directing the thermal laser beam (34) at the source (20) through an aperture (16) located inside the vacuum chamber (12); Includes, The step of directing the thermal laser beam (34) via the thermal laser beam shaping system (40) is performed by the shaping device (60) to provide at least one of the position, shape and size of the thermal laser beam (34) in the source (20), The step of directing the thermal laser beam (34) via the thermal laser beam shaping system (40) is: The collimating lens (42) converts the flared laser beam (34) supplied by the laser light source (30) into a parallel laser beam (34), and subsequently, the focusing lens (44) receives the parallel laser beam (34) and directs this laser beam (34) toward the source (20), thus the collimating lens (42) and the focusing lens (44) are configured to be compatible with each other. The shaping device (60) preserves the parallel alignment of the thermal laser beam (34) after the collimating lens (42), and thus keeps the focal volume at which the focusing lens (44) focuses the laser beam (34) stationary in the same location within the vacuum chamber (12). The method is characterized in that the collimating lens (42) and the focusing lens (44) are stationary within the thermal laser beam shaping system (40) relative to the source (20) and the laser light source (30).
14. The method according to claim 13, characterized in that the method is carried out by a thermal laser evaporation system (10) according to one of claims 1 to 12.
15. The method according to 13 or 14, characterized in that the shape of the thermal laser beam (34) is adapted by cutting out a portion of the thermal laser beam (34) and / or by using a combination of an anamorphic prism pair and / or a cylindrical lens and / or a free-form mirror to change the shape of the thermal laser beam (34).
16. The method according to 15, characterized in that the thermal laser beam (34) supplied by the laser light source (30) having a circular cross-section (38) is transformed by the shaping device (60) into a thermal laser beam (34) having an elliptical cross-section (38).
17. The method according to any one of 13 to 16, characterized in that the size of the thermal laser beam (34) is adjusted by cutting out a portion of the thermal laser beam (34) and / or by using a harmonized pair of defocusing lenses (44) and focusing lenses (44) and / or a beam compressor and / or a beam expander and / or a free-form mirror.
18. The method according to any one of 13 to 17, characterized in that the position of the thermal laser beam (34) of the source (20) is adapted by cutting out a portion of the thermal laser beam (34) and / or by using a position-adjusting element (66) that changes the position of the thermal laser beam (34) in the beam shaping system with respect to the optical axis of the thermal laser beam (34).
19. The method according to 18, characterized in that positioning the thermal laser beam (34) includes scanning the laser beam (34) across the source (20) by moving at least one of the positioning elements (66) with a drive unit (50) of the thermal laser beam shaping system (40).
20. The method according to any one of 13 to 19, characterized in that the step of directing the thermal laser beam (34) via the thermal laser beam shaping system (40) includes dividing the thermal laser beam (34) coming from the laser light source (30) into two or more partial laser beams (36) by a splitting device (46) of the thermal laser beam shaping system (40).
21. The thermal laser beam shaping system (40) focuses the thermal laser beam (34) to a point focal volume located between the vacuum window (12) and the source (20) in the vacuum chamber (12), and an aperture (16) is positioned in the point focal volume having an aperture opening (18) of the aperture, thereby protecting the vacuum window (12) from particles evaporated from the source (20), according to any one of the methods of 13 to 20.