Measuring apparatus for edge profile examination, in particular edge profile determination and / or edge inspection, of a measurement object, in particular a wafer, and method therefor
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-10
- Publication Date
- 2026-08-13
Smart Images
Figure AT2026060032_13082026_PF_FP_ABST
Abstract
Description
[0001] Measuring device for edge profile examination, in particular edge profile determination and / or edge inspection, of a measuring object, in particular wafers, and methods for this purpose
[0002] The invention relates to a measuring device for edge profile examination, in particular edge profile determination and / or edge inspection, of a typically disc-shaped measuring object, in particular wafers, wherein the measuring device has a lighting device and a camera to form a light curtain with laser light in a measuring plane with the lighting device, wherein a recording direction of the camera is oriented transversely, in particular orthogonally, to the measuring plane in order to record with the camera a scattered light scattered by the light curtain on the measuring object when the measuring object is arranged transversely to the light curtain.
[0003] The invention further relates to a method for determining the edge profile of a measuring object, usually disc-shaped, in particular a wafer, wherein a light curtain formed with laser light is created in a measuring plane using an illumination device, wherein a measuring object arranged transversely to the light curtain is irradiated by the light curtain, wherein a camera in a recording direction transverse, in particular orthogonal, to the measuring plane records scattered light from the light curtain on the measuring object and determines the edge profile of the measuring object based on the recorded scattered light.
[0004] Furthermore, the invention relates to a method for edge inspection of a measuring object, usually disc-shaped, in particular wafers, wherein a light curtain formed with laser light is created in a measuring plane with an illumination device, wherein a measuring object arranged transversely to the light curtain is irradiated by the light curtain, and wherein a camera in a recording direction transverse, in particular orthogonal, to the measuring plane captures scattered light from the light curtain on the measuring object.
[0005] Wafers used in semiconductor device manufacturing are typically subjected to testing to ensure quality requirements, particularly regarding reliability. This usually involves inspecting the edge profile of the wafer, especially its edge region, for integrity. Known measurement methods for this purpose involve moving an edge region of the wafer through a laser light curtain to project a light line onto the edge region. A camera captures a lateral edge profile of the edge region to record scattered light from the light curtain or light line at the surface of the edge region. Irregularities and / or defects in the edge region can then be correlated with changes in the scattered light, particularly its intensity.
[0006] This is where the invention comes in. The object of the invention is to provide a measuring device for determining the map profile of the type mentioned above, which exhibits a high degree of practicality in use.
[0007] A further object of the invention is to provide a method of the type mentioned above for determining edge profiles, which has a high degree of practical applicability.
[0008] Furthermore, it is an object of the invention to provide a method of the type mentioned above for edge inspection which has a high degree of practical applicability.
[0009] The object of the invention is achieved in that, in a measuring device of the type mentioned at the outset, the lighting device has a laser light source and a beam splitter device in order to use the beam splitter device to separate a source laser beam emitted by the laser light source into several partial beams and to direct them in such a way that the partial beams from different directions form the light curtain in order to irradiate the object being measured from different directions with the partial beams.
[0010] The invention is based on the idea of illuminating the object being measured, in particular an edge region of a wafer, from different directions while simultaneously achieving a user-friendly measurement setup, especially one with a compact design and / or low maintenance requirements. In practice, a light curtain is typically used to illuminate the object being measured, particularly a surface section, in a generally linear fashion. To minimize, and preferably avoid, shadows on the illumination caused by the object being measured, especially its surface, it is advantageous if, in practice, the irradiation directions of the partial beams are directed onto the object being measured from different directions to form the light curtain.In operation, the object being measured is typically positioned in an arrangement plane for irradiation with the light curtain. This arrangement plane is usually oriented transversely, and in particular orthogonally, to the measurement plane. The beam path direction is usually...
[0011] The beam splitter is positioned downstream of the laser light source, following the direction of light propagation of the source laser beam. The beam splitter can be configured to separate and direct the partial beams in such a way that one or more of the partial beams are deflected, and in particular, one of the partial beams maintains an orientation with which the source laser beam reaches the beam splitter. It is advantageous if the beam splitter directs a second partial beam from above and a third partial beam from below onto the plane of the array. Specifically, the beam splitter can align a first partial beam with the plane of the array. This applies particularly to an irradiation section of the respective partial beam. The partial beams are typically directed, and in particular aligned, accordingly by the beam splitter.
[0012] Typically, the partial beams, particularly their irradiation segments, are aligned with the measurement plane, intersecting each other in the measurement plane. Attempts were made to use source laser beams from several separate laser light sources, especially three separate laser light sources, instead of the partial beams. These source lasers are steered analogously to the partial beams. However, it has been shown that this complicates the measurement setup and often leads to the problem that multiple laser light sources are subject to different aging processes with regard to their beam behavior. This can negatively impact the evaluation of camera images of the scattered light and / or necessitate corresponding considerations during maintenance intervals.By implementing the lighting system with a beam splitter to divide the source laser beam into several partial beams, this problem can be largely avoided. This approach achieves a high degree of practicality in application.
[0013] Directing the partial beams with the beam splitter device typically refers to predefining a path for the partial beams and / or adjusting the partial beams, in particular by deflecting at least one or more of the partial beams, whereby the deflection can be implemented by refraction and / or reflection. The irradiation section of the respective partial beam typically refers to a section of the partial beam with which the light curtain is formed and / or which, when used to illuminate the object being measured, strikes the object being measured. The irradiation direction of the respective partial beam typically refers to a direction of the irradiation section of the partial beam.The term "deployment," particularly of the measuring device, typically refers to a state in which, for determining the edge profile of the object being measured, the object is positioned across the light curtain in order to capture, and especially to store, scattered light diffused by the light curtain at the object being measured. Specifically, the measuring device can be operated in deployment mode and / or direct the source laser beam or the partial beams as described in this document.
[0014] Typically, the partial beams, and in particular their irradiation segments, point in different directions, especially irradiation directions, to form the light curtain and / or to irradiate, and in particular illuminate, the object being measured. This applies especially during the use of the measuring device. The partial beams can be directed by the beam splitter such that the irradiation directions or the irradiation segments have a common intersection point in the plane of the arrangement and / or, when used on the object being measured, especially its edge region. As a rule, each partial beam, and in particular its irradiation segment, has a linear light beam cross-section for the, in particular, linear, irradiation of the object being measured. For this purpose, the source laser beam can be emitted from the laser light source with such a light beam cross-section.The lighting device is typically designed to shape the respective partial beam, in particular its irradiation segment, accordingly. Typically, especially in operation, the object being measured is irradiated, and in particular illuminated, with the respective partial beam, particularly in a linear fashion.
[0015] It is advantageous if the partial beams are directed by the beam splitter such that the object being measured is illuminated by the partial beams on a top and bottom surface, and preferably on a lateral surface, particularly in a linear fashion. The beam splitter is usually designed accordingly. In this way, shadows on the light curtain caused by the shape and / or surface structure of the object being measured can be significantly reduced, and / or a high degree of clarity in assessing the edge profile of the object being measured can be achieved using the camera images of the scattered light. The lateral surface typically refers to a side of the object being measured that is oriented transversely, and in particular orthogonally, to the plane of arrangement. The top and / or bottom surface of the object being measured are usually oriented essentially parallel to the plane of arrangement. The above applies particularly during the use of the measuring device.
[0016] Typically, each partial beam forms the light curtain with an irradiation section of the partial beam. For high accuracy in edge profile determination, it has proven advantageous if the irradiation sections of the partial beams, particularly for forming the light curtain and / or for irradiating the object being measured with the partial beams, are arranged coplanarly in a common plane, usually in the measurement plane. The partial beams can be directed accordingly by the beam splitter. The irradiation sections of the partial beams usually each lie in the measurement plane. The above applies analogously to the irradiation directions of the partial beams. The beam splitter can be configured to direct the partial beams, and in particular, to implement this. The above applies especially during the use of the measuring device.
[0017] The partial beams can comprise a first partial beam and / or a second partial beam and preferably a third partial beam. It is advantageous if the irradiation section of a first partial beam lies in the plane of the arrangement. The irradiation section of the first partial beam preferably runs along the intersection of the plane of the arrangement and the measurement plane. The irradiation section of a second partial beam, and preferably the irradiation section of a third partial beam, can each be aligned at an orthogonal angle to the plane of the arrangement. The angle of alignment is typically less than 80°, particularly between 10° and 80°, preferably between 45° and 75°, and most preferably between 55° and 70°.The irradiation direction of the irradiation segment of the second partial beam and / or the irradiation direction of the irradiation segment of the third partial beam is usually oriented towards the plane of arrangement. The orthogonal alignment angle is typically measured in a plane oriented orthogonally to the plane of arrangement through the irradiation segment of the respective partial beam. The irradiation segment of the second partial beam and the irradiation segment of the third partial beam can have irradiation directions oriented towards the plane of arrangement on opposite sides of the plane of arrangement, or, in the case of use, on opposite sides of the object being measured. The irradiation segment of the second partial beam and the irradiation segment of the third partial beam can then have a substantially equal orthogonal alignment angle with the plane of arrangement.In operation, the second and third partial beams, and in particular their respective irradiation sections, can be directed at the object being measured from opposite sides with respect to the plane of arrangement. For example, the second partial beam, and in particular its irradiation section, can irradiate the top side of the object being measured, and the third partial beam, and in particular its irradiation section, can irradiate the underside of the object being measured, or analogously in the reverse direction. The illumination device, in particular the beam splitter device, can be configured to direct the partial beams, and in particular to be set up, such that the above is implemented.
[0018] It is particularly advantageous if, for the formation of the light curtain, the irradiation section of the first partial beam lies in the arrangement plane and the irradiation sections of the second and third partial beams are oriented symmetrically, in particular mirror-symmetrically, to each other with respect to the arrangement plane. The lighting device, in particular the beam splitter device, can be designed to direct the partial beams accordingly, in particular to adjust them.
[0019] It is practical to separate and direct the partial beams using the beam splitter device, such that the irradiation section of one partial beam, particularly the first partial beam, is aligned with the optical axis of the laser light source. Specifically, the beam splitter device can be designed to form and direct the partial beam, particularly the first partial beam, while maintaining the orientation with which the source laser beam approaches the splitter device, or without deflecting its laser light. This has proven advantageous for a compact design. The optical axis of the laser light source can be oriented in the arrangement plane and / or the measurement plane. Specifically, the optical axis of the laser light source can run along the intersection of the arrangement plane and the measurement plane.The optical axis of the laser light source usually refers to an axis along which the source laser light is emitted from the laser light source.
[0020] The lighting device, in particular the beam splitter, may be configured to direct the partial beams, specifically to achieve an arrangement and / or orientation of the partial beams described in this document, particularly their irradiation sections and / or irradiation directions. An arrangement and / or orientation of a laser beam described in this document, in particular one of the partial beams, specifically its irradiation section or irradiation direction, and / or the source laser beam, applies especially during the use of the measuring device.
[0021] The beam splitter device can be configured to split the source laser beam into partial beams and / or to direct the partial beams so that one or more of the partial beams are deflected. The beam splitter device can have one or more beam splitters to split the source laser beam into partial beams and, in particular, to direct one or more of the partial beams. The respective beam splitter can include a prism. The respective beam splitter can be configured to separate and deflect a portion of the laser light from the source laser beam to form and direct one of the partial beams. This can be achieved by refraction and / or reflection of the laser light portion at one or more interfaces of the beam splitter, in particular the prism.Deflecting one of the partial beams with the beam splitter typically refers to changing the direction of the laser light of the partial beams relative to the orientation with which the source laser beam approaches the beam splitter. It is advantageous if the beam splitter is designed to form and deflect one of the partial beams with laser light from the source laser beam while maintaining the orientation with which the source laser beam approaches the beam splitter, particularly by guiding it through the beam splitter. This allows the irradiation section of the partial beam to be formed with a corresponding orientation. For this purpose, the beam splitter can have a path along which a portion of the laser light from the source laser beam, in the form of the partial beam, is guided through the beam splitter without deflection.For example, this partial beam can be the first partial beam. The beam splitter can be designed accordingly. Preferably, the respective prism is a Littrow prism.
[0022] It is practical for the beam splitter to have a first beam splitter for separating one of the partial beams, for example, the second partial beam, and a second beam splitter for separating another of the partial beams, for example, the third partial beam, from the source laser beam. The separation of each partial beam is usually achieved by deflecting the laser light of that partial beam, in particular its laser light, with the respective beam splitter. A residual beam of the source laser beam that is not separated and deflected by the first and second beam splitters can form another partial beam, in particular the first partial beam, preferably while maintaining the orientation with which the source laser beam strikes the beam splitter. The further partial beam, in particular the first partial beam, can then form its irradiation section with this orientation.In the direction of light path of the source laser beam, the beam splitter can have a through-opening between the first and second beam splitters, through which the subsequent partial beam, in particular the first partial beam, is guided without being deflected by the beam splitter. The through-opening can form the aforementioned path. The first beam splitter can be a prism. The second beam splitter can be a prism.
[0023] The prism in question can have a triangular shape in a cross-section along the measuring plane, wherein the prism in question is arranged and designed in such a way that, in order to separate the respective partial beam from the source laser beam, a laser light part of the source laser beam penetrates into the interior of the prism, forming the partial beam, usually with refraction of the laser light part at an interface of the prism, and is deflected with refraction and / or reflection of the partial beam at one or more further interfaces of the prism.It has proven effective if the prism is arranged and designed such that a portion of the source laser beam, refractiveed at a first interface of the prism, enters the prism's interior, is then reflected, particularly by total internal reflection, at a second interface, and subsequently deflected by reflection at a reflective surface. This reflective surface can be a third interface of the prism, especially one with a reflective, particularly specular, coating applied to it. The first, second, and third interfaces are typically distinct interfaces of the prism.The prism in question can have a cross-sectional shape resembling a right triangle, whereby, in particular, the portion of the laser light from the source laser beam that forms the partial beam enters the prism along one of the legs of the triangle, and typically exits the prism along one of the hypotenuses. The second interface can correspond to the hypotenuse in cross-section. The first interface and the second interface can each correspond to one of the legs in cross-section.
[0024] It is practical if the first and second beam splitters are arranged on different, particularly opposite, sides with respect to the source laser beam, especially in a view along the source laser beam. For example, one of the beam splitters can be arranged above the source laser beam and the other below it. Each beam splitter typically projects into the source laser beam to separate a partial beam from the source laser beam. Specifically, the first and second beam splitters can be arranged symmetrically, particularly mirror-symmetrically, with respect to the source laser beam. This can be the case, in particular, in a cross-section through the source laser beam along the source laser beam and / or in a cross-section through the source laser beam orthogonal to the source laser beam, especially in a region of the beam splitters.The beam splitters can be arranged such that a portion of the laser light from the source laser beam strikes each beam splitter, separating the respective partial beam from the source laser beam. The respective beam splitter can be arranged such that it overlaps a segment of the source laser beam's cross-section to separate the respective partial beam. For high practicality, it is advantageous if the measuring device includes a partial beam blocking device for the controlled blocking of one or more of the partial beams, so that the respective partial beam no longer contributes to the formation of the light curtain when blocked by the partial beam blocking device.The partial beam blocking device can have a blocking element for blocking the respective partial beam, wherein the blocking element is controllably movable into a beam path of the partial beam, in particular the irradiation section of the partial beam, so that the beam path is interrupted by the blocking element. For this purpose, the blocking element can be movable, in particular pivotable, relative to a blocking element base of the partial beam blocking device. The partial beam blocking device can be designed accordingly, in particular having a control mechanism for moving the blocking element. For example, the partial beam blocking device can have such a blocking element for blocking the first partial beam. The partial beam blocking device can have several such blocking elements, in particular each with its own blocking element base, for the controlled blocking of several of the partial beams with the blocking elements.It is advantageous if the partial beam blocking device is designed to block the respective partial beam in a controlled manner after the partial beam has exited the beam splitter device.
[0025] It has proven advantageous to arrange several apertures, in particular slit apertures, of the measuring device one after the other between the laser light source and the beam splitter device, so that, especially in operation, the source laser beam is guided through the apertures in order to reduce, in particular to avoid, scattering reflections of the laser light of the source laser beam, and / or to limit a cross-section of the source laser beam.
[0026] The light curtain typically represents a light field lying in the measurement plane, particularly for forming a light section. In operation, the light field usually forms a line of light on the object being measured as it crosses the light field. The light field can be formed by one or more laser beams, particularly line beams, which can specifically be the partial beams, or more precisely, their irradiation segments. The illumination device for forming the light curtain usually includes the laser light source. The light curtain can be formed by the source laser beam emitted by the laser light source, in particular by its laser light.
[0027] The camera typically has a lens for capturing stray light. It is advantageous if the camera, along its optical beam path, has an optical deflection device, in particular a deflection prism, positioned downstream of the lens, usually between the lens and the object being measured, to deflect the optical beam path such that an optical axis of the lens and the camera's recording direction form a deflection angle between 85° and 110°, preferably 90°. The optical deflection device is typically designed to transfer the beam path between a section of the camera beam path along the optical axis of the lens and a section along the recording direction by deflecting the beam path, particularly with the aforementioned deflection angle.In particular, this allows for a particularly compact measurement setup. The recording direction typically refers to the camera's viewing direction towards the object being measured and / or the surface. The camera usually has an image sensor for detecting, and especially storing, an image of the section of the object being recorded, with the image sensor typically positioned in front of the lens along the camera's optical path. The camera usually captures an image of a scattered light fringe formed by the scattered light. Several images of each scattered light fringe can be captured. The camera recording typically includes one or more such images. The scattered light fringe typically corresponds to an edge profile or...The edge profile of a given area of the object being measured, illuminated by the light curtain, particularly the light line, and specifically from which the image is captured, is defined. The scattered light fringe typically runs along the edge of the respective area being measured. This scattered light fringe can also be referred to as the scattered light profile line. By analyzing the scattered light fringe in the image, the edge profile of the illuminated area can be determined. This analysis is usually performed using software. Typically, different areas of the object being measured are sequentially illuminated by the light curtain, and an image of the scattered light fringe formed by the scattered light is captured with the camera in each case. In this way, changes in the edge profile between the areas of the object being measured can be determined by analyzing the captured scattered light fringes.It is advantageous to move the object being measured through the light curtain in order to successively capture the scattered light fringes of different areas of the object being examined. The areas being examined are preferably the edges of the object being measured, in particular the edges of a wafer.
[0028] The recording direction is usually oriented transversely, and in particular orthogonally, to the measuring plane. An orthogonal recording angle between the recording direction and the measuring plane can be 85° to 95°, and in particular 90°. The orthogonal recording angle is usually measured in a plane oriented orthogonally to the measuring plane through the recording direction. The recording direction can lie in the arrangement plane. The camera is usually arranged accordingly. The camera can be oriented such that it records an edge profile of the object being measured. The measuring device, in particular the camera, can be implemented such that, with respect to any recorded light, it essentially, and in particular exclusively, records the scattered light, which is usually caused by the light curtain. The lens is usually focused on the measuring plane.It is advantageous if the camera, in particular the lens, is arranged confocally with respect to the light curtain, in particular a linear illumination caused by the light curtain or the partial rays on the object being measured.
[0029] The thickness of the light curtain, particularly the irradiation sections of the partial beams, can be less than 100 pm, especially between 1 pm and 50 pm, preferably between 1 pm and 20 pm. This allows for high accuracy in edge profile determination. The camera's recording direction is typically aligned to capture an edge profile of the object being measured, particularly a lateral one, and scattered light from the light curtain along the edge profile.
[0030] It is advantageous if the measuring device, in particular the camera, has an adjustment device for varying the focus of the camera, especially the lens, and / or for varying the height of the camera's beam path in a direction orthogonal to the plane of arrangement. For this purpose, the adjustment device can include a drive unit to achieve this. This allows the camera image to be adapted to the dimensions of an object. The adjustment device can be configured to change the optical distance between the lens and the measuring plane to vary the camera's focus, particularly with one of the drive units.
[0031] It is advantageous if the camera has a filter tuned to a specific wavelength of the laser light source and / or a wavelength of the light curtain and / or a wavelength of the scattered light to filter ambient light with a different wavelength. The filter is typically arranged in the camera's optical path to reduce the ambient light in the camera image, in particular to filter it out entirely. The filter can be positioned downstream of the lens along the camera's optical path, in the direction of the section of the object being measured, and especially between the lens and the deflection device. The filter can be an interference filter, particularly a line interference filter.
[0032] The laser light source can be any laser radiation source, particularly one corresponding to the purpose of the invention. In particular, the laser light source can be configured to emit the source laser beam with a laser wavelength in a region of the electromagnetic spectrum encompassing the UV, visible, and infrared regions. A wavelength of less than 570 nm, more preferably less than 490 nm, more preferably less than 430 nm, and more preferably less than 380 nm, is preferred for the laser light wavelength of the source laser beam. Laser light or light described in this document typically refers to electromagnetic radiation of the aforementioned electromagnetic spectrum, in particular the laser light emitted by the laser light source.The light curtain and / or the scattered light can have a wavelength in a region of the electromagnetic spectrum, including the UV, visible, and infrared ranges, with the wavelength generally corresponding to the laser wavelength of the source laser beam. A simple and, in particular, low-maintenance measurement setup is achievable if the measuring device has exactly one laser light source for forming the light curtain and / or the light curtain is formed by the laser light of exactly one laser light source. It has proven particularly advantageous if the object being measured is a wafer, especially...
[0033] The object being measured is a semi-conductor wafer, preferably an edge region of the wafer, particularly a semiconductor wafer. This allows for a particularly practical quality test to determine the edge profile of the wafer, specifically its edge region. The object being measured, especially the wafer, is typically positioned in the plane of the arrangement for irradiation with the light curtain, particularly the partial beams, such that a longitudinal axis, and preferably a width axis, of the object being measured, especially the wafer, is oriented substantially along the plane of the arrangement. The length and width of the object being measured are typically each smaller than the height of the object being measured. The length is usually measured along the longitudinal axis, the width along the width axis, and the height along a height axis of the object being measured. The longitudinal axis, width axis, and height axis of the object being measured are typically oriented orthogonally to each other.The object being measured can be part of the measuring device. In particular, the object being measured can be positioned across the light curtain in order to capture the scattered light dispersed by the light curtain onto the object being measured with the camera.
[0034] It is advantageous to have a measuring system comprising the measuring device. The measuring device can be configured as described in this document. The measuring system can include a fixture for positioning and / or moving the object relative to the measuring system, particularly in a controlled manner. The fixture can be configured to position the object in the plane of the measuring system, particularly in a controlled manner, so that, especially during operation, the object crosses the light curtain of the measuring device, in order to perform edge profile determination of the object. The measuring system can include a base on which the measuring device is mounted. The base can be rigidly connected to the fixture. The measuring device can be movably connected to the base, particularly in a guided manner, relative to the base.In this way, the relative distance and / or orientation between the measuring device and the object being measured can be adjusted during operation. It is advantageous if the measuring device is rotatably connected to the measuring device base around an axis of rotation, particularly if guided by this axis. The axis of rotation can be oriented orthogonally to the arrangement plane and / or parallel to the measuring plane. It is advantageous if the axis of rotation passes through the light curtain and, in particular, lies in the region of an outer edge of the object being measured. In this way, depending on the size of the object being measured, the distance between regions of the object being measured and regions of the measuring device that are not positioned within the area of the light curtain can be varied by rotating the measuring device relative to the measuring device base. This is particularly relevant when viewed orthogonally to the arrangement plane.It is advantageous if the measuring device is rotatable relative to the measuring device base by an angle of rotation of at least 2°, in particular at least 5°, preferably at least 10°, about the axis of rotation. It is expedient if the angle of rotation is a maximum of 45°. The measuring device and the measuring device base can be guided by a guide of the measuring system and be movable relative to each other, in particular rotatable. The guide can have a guide element receptacle and a guide element inserted, in particular positively, into the guide element receptacle, so that the guide element is guided by the guide element receptacle. The guide element can be part of the measuring device and the guide element receptacle can be part of the measuring device base, or this can be implemented accordingly in reverse. Advantageously, the guide can have several such guide elements and corresponding guide receptacles for the guide elements.For example, the measuring device base can have several guide receptacles implemented with guide slots and the measuring device can have several guide pins corresponding to the guide slots, wherein the guide pins are inserted into the guide slots in a form-fitting manner so that, by moving the guide pins in the guide slots, the measuring device can be rotated relative to the measuring device base about the axis of rotation.
[0035] The further task is solved using a method of the type mentioned above for edge profile determination, if the illumination device comprises a laser light source and a beam splitter, wherein the source laser beam emitted by the laser light source is split into several partial beams by the beam splitter, wherein the partial beams are directed, in particular arranged, such that the partial beams from different directions form the light curtain in order to irradiate the object being measured from different directions with the partial beams. The irradiation of the object being measured with the partial beams, in particular with the respective partial beam, is usually a line-like illumination of the object being measured with the partial beams, in particular with the respective partial beam. The irradiation of the object being measured with the partial beams or with the light curtain can be a light section.The method can be implemented using the measuring device described in this document. The method for determining the edge profile can be designed according to the features and effects described in this document, particularly above, within the context of the measuring device. This also applies analogously to the measuring device with regard to the method.
[0036] Typically, the object being measured is arranged in a plane, with the measuring plane being oriented transversely, and in particular orthogonally, to the plane of arrangement. Preferably, the partial beams are directed by the beam splitter such that an irradiation segment of the respective partial beam, with which the light curtain is formed and / or which irradiation segment strikes the object being measured, lies in the measuring plane. This usually applies accordingly to an irradiation direction of the irradiation segment.
[0037] It is advantageous if the object being measured is moved, in particular guided, through the light curtain, whereby, in particular successively, different areas of the object are illuminated with the light curtain, in particular with the partial beams, and, usually assigned to the areas being measured, an image of the scattered light from the light curtain on the object being measured, usually in the form of a scattered light fringe, is recorded, in particular detected and / or stored. The edge profile of the object being measured, in particular of the respective area being measured, can be determined based on the scattered light fringe of the respective image, in particular an edge profile and / or an intensity of the scattered light fringe. This can be implemented by computer, in particular with a data processing unit of the measuring device. The determination of the edge profile can be carried out, in particular by computer, with an evaluation procedure.The evaluation procedure typically includes the aforementioned determination of the edge profile based on the scattered light fringe of the respective image. The determination of the edge profile, in particular the edge distribution, can be implemented, for example, using a least-squares adjustment, especially a regression analysis.The further specified problem is solved with a method of the type mentioned at the outset for edge inspection if the illumination device comprises a laser light source and a beam splitter device, wherein a source laser beam emitted by the laser light source is split into several partial beams by the beam splitter device, wherein the partial beams are directed in such a way that the partial beams from different directions form the light curtain in order to irradiate the object being measured from different directions with the partial beams, wherein different areas of the object being measured are successively irradiated by the light curtain, in particular by moving the object being measured through the light curtain, and an image of a scattered light fringe formed by the scattered light is recorded for each of the areas being measured, after which the intensity distributions of the scattered light fringes are compared and / or graphically represented.Moving the object being measured can involve rotating the object being measured, in particular around an axis of rotation passing through a center point of the object being measured, which is usually orthogonal to the plane of arrangement.
[0038] Edge inspection, often also called surface inspection, is typically used to detect contamination and / or surface defects on the surface of the object being measured. Preferably, the location and / or extent of these defects is determined. In known edge inspection methods, the surface of the object is usually examined using at least three cameras operating in bright-field mode, each of which focuses adaptively on the object's surface independently. It has been shown that edge inspection with high practicality can be performed using the measuring device and / or the edge inspection method described in this document.
[0039] The camera image, or the images captured with the camera, are typically dark-field images. Preferably, the images essentially depict only the scattered light, in particular the scattered light fringe. The camera image of the various areas of the object being measured is usually taken with the same camera focus. The focus is generally not changed during the application of the method to the object being measured. The respective image typically represents the scattered light fringe in a pixel-based manner. The respective image can be implemented using image data, particularly pixel-based data. The scattered light fringe of the respective image typically represents scattered light from a top, bottom, and preferably lateral side of the object being measured. The camera is typically configured for a corresponding camera image. The method can be implemented with the measuring device described in this document.The edge inspection method can be designed according to the features and effects described in this document, particularly above, within the context of the measuring device and / or the edge profile determination method. This also applies analogously to the measuring device and / or the edge profile determination method with regard to the edge inspection method.
[0040] It is advantageous to determine the intensity distribution of the scattered light fringe along the edge profile of the scattered light fringe for each image, particularly for comparing and / or graphically representing the intensity distributions of the scattered light fringes. The intensity distributions of the scattered light fringes in the images can be represented by the intensity distributions along the respective edge profile. The edge profile of the scattered light fringe typically refers to the scattered light fringe along one or more surface edges of the object being measured, as captured by the camera, and which surface is illuminated by the light curtain.
[0041] Surface edges of the edge profile. The surface edge typically runs along a top, bottom, and preferably a lateral side of the object being measured. Similarly, the edge profile of the scattered light fringe typically runs along a top, bottom, and preferably a lateral side of the object being measured.
[0042] In practical terms, an edge profile of the measured object can be determined based on the scattered light fringe of the respective image. This can be implemented as described in this document. The edge profile of the scattered light fringe can correspond to the profile of the determined edge profile.
[0043] It is advantageous if, for each image, edge positions representing the edge path of the scattered light fringe are assigned an intensity value based on the intensities of several pixels of the image located above and below the edge position, parallel to a vertical direction of the edge path, preferably according to a clustering distance associated with the edge position. This allows the intensity distribution of the scattered light fringe along the edge path to be determined. The vertical direction typically denotes a direction perpendicular, particularly orthogonal, to the edge path, especially in the region of the respective edge point. The intensity value can, for example, be calculated as the sum of the pixel intensities. It is advantageous if, for each image, the edge positions are defined by pixels located along the edge path of the scattered light fringe.For each image, intensity data, for example in the form of a data vector or a data series representing the intensities of the edge positions, can be determined and, in particular, stored. The intensities of the edge positions of the respective image can represent the intensity distribution of the scattered light fringe of the respective image. The edge positions can be points of the edge profile defined for the respective image or the respective investigation area. Accordingly, it is advantageous if, before determining the intensity distribution, especially the intensity values, of the respective image, the respective edge profile is determined as described in this document, in particular according to the procedure for edge profile determination.
[0044] It is practical to calculate the intensity value based on the intensities of pixels within a clustering distance oriented parallel to the height direction from the edge position. The clustering distance can be predefined, particularly based on user input, and / or determined automatically. The clustering distance can include an upper and a lower clustering distance, with the upper distance measured parallel to the height direction in a direction away from the edge profile, and the lower distance measured parallel to the height direction in a direction towards the edge profile. The intensity value can then be calculated based on the intensities of pixels within the upper and lower clustering distances from the edge position in the respective directions.The clustering distance, particularly the upper and / or lower clustering distance, can be between 1% and 50% of the average width of the edge profile in the image in the vertical direction. It is practical if the clustering distance, particularly the upper and / or lower clustering distance, is a maximum of 40%, more preferably a maximum of 30%, preferably a maximum of 20%, and more preferably a maximum of 10% of the average width of the edge profile in the image in the vertical direction. Typically, the clustering distance, particularly the upper and / or lower clustering distance, is greater than 5% of this width. The width is usually represented by an average distance between sections of the light fringe that correspond to a top and bottom surface of the area under investigation.It has proven effective to assign an equal clustering distance, particularly an upper and / or lower clustering distance, to each edge position in the respective image. In the image, the clustering distance can represent an imaginary cluster strip superimposed on the edge of the scattered light fringe, with the edge of the cluster representing the clustering distances to the respective edge positions. The pixels located in a direction parallel to the respective height direction between the edges of the cluster strip and the respective edge position can be used to calculate the intensity value of the edge position.
[0045] It is advantageous to graphically represent the intensity distributions of the scattered light fringes using a scatter diagram, often referred to as a scatter intensity map, to depict intensity variations along a surface of the object under test. Preferably, the scatter diagram displays the intensity distributions along the edge profiles of the scattered light fringes of the images side by side. It is preferred that one dimension of the scatter diagram represents the edge positions and another dimension identifies the different images or the corresponding test areas on the object under test. This identification can, for example, specify the position of the test areas on the object under test.The position can be specified, for example, by a polar angle running along the circumference of the object being measured, particularly when the object is moved through the light curtain while rotating along its circumference. The intensity values are usually measured, preferably with a...
[0046] The intensity values of the edge points of each image are displayed in the scatter plot using a light-dark scheme and / or a color scheme. The respective dimension is typically an axis of the scatter plot. It has proven effective to display the intensity values of the edge points of each image as a series, side by side, in the direction of the dimension of the edge positions in the scatter plot, particularly with the light-dark scheme and / or color scheme. In this way, the scatter plot represents a two-dimensional surface in which the intensity values are displayed, preferably with the light-dark scheme and / or color scheme. This allows for efficient and highly practical edge inspection. Contamination and / or surface defects can be detected and spatially localized particularly effectively in this manner.In practical application, the intensity distributions of the scattered light fringes are graphically represented using a two-dimensional surface to depict intensity fluctuations along the surface of the object being measured. Preferably, the intensity distributions, and in particular the intensity values, along the edges of the scattered light fringes are shown side by side in the two-dimensional surface. This can be implemented using a scatter plot.
[0047] The scattered light fringes of the images, especially intensity distributions or...
[0048] The intensity values of the images are typically related to each other using corresponding reference points. It has proven useful to select a point on a lateral edge of the respective scattered light fringes as the corresponding reference point. This point is preferably the midpoint of a length along the lateral edge of the scattered light fring. The lateral edge usually corresponds to the lateral side of the respective area under investigation. In this way, the scattered light fringes, and especially their intensity distributions, can be practically related to each other. The lateral side of the scattered light fring typically corresponds to the lateral side of the object being measured.The evaluation of the images based on the scattered light fringe, in particular the determination and / or representation of the intensity distributions, is usually carried out using computer-implemented methods, especially with an evaluation procedure.
[0049] Partial beams typically refer to separate laser beam bundles, which in particular have different beam paths. The measurement plane and / or the arrangement plane usually represent imaginary planes used especially to describe the measuring device or the method. The measurement plane and / or the arrangement plane are usually part of the measuring device. The irradiation direction of the respective partial beam usually refers to an orientation of the irradiation section of the respective partial beam. The respective irradiation direction usually runs along the respective irradiation section.
[0050] Further features, advantages, and effects of the invention will become apparent from the following description of an exemplary embodiment. The drawings referred to therein show:
[0051] Fig. 1 shows a schematic representation of a measuring device for determining the edge profile of a wafer arranged in an arrangement plane;
[0052] Fig. 2 is a schematic representation of a section of the measuring device of Fig. 1 in a perspective view;
[0053] Fig. 3 shows a schematic representation of a cross-section of the measuring device of Fig. 1 orthogonal to the measuring plane;
[0054] Fig. 4 shows a schematic representation of a section through the measuring device of Fig. 1 parallel to the measuring plane;
[0055] Fig. 5 shows a schematic representation of a cross-section through the measuring device of Fig. 1 parallel to the measuring plane;
[0056] Fig. 6 is a schematic representation of a cross-section of the measuring device of Fig. 1 orthogonal to the measuring plane, wherein the measuring device is rotated relative to the object being measured; Fig. 7 is a camera image of a lateral edge profile of the wafer, wherein the camera image shows scattered light from the light curtain on the object being measured in a negative representation;
[0057] Fig. 8 shows a flow diagram of a section of a process for edge inspection of the wafer;
[0058] Fig. 9 shows an image of a light fringe taken with the camera, illustrating the determination of an intensity distribution of the scattered light fringe along an edge profile of the light fringe;
[0059] Fig. 10 shows a scattering diagram in which intensity distributions of scattered light fringes from test areas distributed along a circumferential direction of the wafer are arranged side by side.
[0060] Figure 1 shows a schematic representation of a measuring device 1 for determining the edge profile of a wafer as the measurement object 4. The measuring device 1 comprises a lighting device 2 and a camera 3 to form a light curtain with laser light in a measuring plane M of the measuring device 1. A recording direction A of the camera 3 is oriented essentially orthogonally to the measuring plane M in order to capture scattered light from the wafer, which is arranged transversely to the light curtain, with the wafer positioned at an angle to the light curtain. The wafer is arranged in an arrangement plane of the measuring device 1 that is oriented orthogonally to the measuring plane M, with a longitudinal axis and a transverse axis of the wafer typically being parallel to the arrangement plane. A camera recording direction A of the camera 3 is aligned to capture a lateral edge profile 16 of the wafer and scattered light from the light curtain at the edge profile 16. In Figure 1, the camera 3 is oriented to capture the lateral edge profile 16 of the wafer and scattered light from the light curtain.Figure 2 is a schematic representation of a section of the measuring device 1 of Fig. 1 in a perspective view. The recording direction A of the camera 3 is generally located in the plane of the arrangement.
[0061] Figure 3 shows a schematic cross-sectional view of the measuring device 1 from Figure 1, orthogonal to the measuring plane M. The cross-section is oriented parallel to the plane of the arrangement. The illumination device 2 has a laser light source 5 for emitting a source laser beam L to form the light curtain. The camera 3 has an image sensor 6, a lens 7, and preferably an optical deflection device, typically in the form of a deflection prism 8, along a camera beam path of the camera 3 in the direction of a measurement section of the object 4 to be recorded with the camera 3, in order to detect and, in particular, to store an image of the measurement section projected onto the image sensor 6 by the lens 7.The deflecting prism 8 is designed to deflect the camera's optical beam path such that an optical axis of the lens 7 and the camera's recording direction A form a deflection angle between 85° and 110°, preferably 90°. In particular, the optical axis of the lens 7 can be arranged substantially parallel to the optical axis of the laser light source 5, with the optical axes preferably lying in the plane of the arrangement. This allows for a compact design. The camera 3 can have a filter 9, in particular an interference filter, tuned to a laser wavelength of the laser light source 5, for filtering ambient light with a different wavelength. The filter 9 in the camera's optical beam path can be arranged between the lens 7 and the deflecting device. It is practical if the measuring device 1 has an adjustment device with a drive unit 10 for varying the focus of the camera 3, in particular the lens 7.The actuator 10 can be implemented as an example with a micrometer adjusting screw in order to vary the focus using screws of the micrometer adjusting screw.
[0062] Fig. 4 shows a schematic representation of a section through the measuring device 1 parallel to the measuring plane M. A part of the measuring device 1 is shown, which includes the illumination device 2. The illumination device 2 comprises the laser light source 5 and a beam splitter 11 formed with two beam splitters 13. The beam splitter 11 splits the source laser beam L into three partial beams and directs them such that the partial beams from different directions form the light curtain. The object being measured 4 can thus be illuminated from different directions with the partial beams. Each beam splitter 13 can be formed by a prism 12. The beam splitters 13 are designed and arranged such that one beam splitter 13 splits a second partial beam from the source laser beam L, and the other beam splitter 13 splits a third partial beam from the source laser beam L.A portion of the source laser beam L that is not separated by the first beam splitter 13 and not by the second beam splitter 13 forms a first partial beam of the partial beams. In the direction of light path of the source laser beam L, the beam splitter device 11 has a through-opening between the first beam splitter 13 and the second beam splitter 13, through which a portion of the source laser beam L that is not separated by the first beam splitter 13 and not by the second beam splitter 13 passes without deflection of the laser light by the beam splitter device 11, forming the first partial beam.
[0063] Between the laser light source 5 and the beam splitter device 11, several apertures 14, in particular slit apertures, of the measuring device 1 are usually arranged one behind the other, wherein the source laser beam L is passed through the apertures 14 in order to reduce, in particular to avoid, scattering reflections of the laser light of the source laser beam L.
[0064] Figure 5 shows a schematic cross-section through the measuring device 1 parallel to the measuring plane M. The partial beams are directed by the beam splitter 11 such that an irradiation section S1 of the first partial beam is oriented essentially along the intersection of the arrangement plane and the measuring plane M, and the irradiation section S2 of the second partial beam and the irradiation section S3 of the third partial beam are each aligned at an orthogonal angle to the arrangement plane in order to form the light curtain with the irradiation sections S1, S2, and S3 of the partial beams. The irradiation section S2 of the second partial beam is oriented from above, and the irradiation section S3 of the third partial beam is oriented from below, towards the arrangement plane and the object being measured 4, respectively. The alignment angle is typically less than 80°, specifically between 55° and 70°.The partial beams are directed by the beam splitter 11 such that the object 4 is illuminated by the partial beams on its top, bottom, and lateral sides. The source laser beam L and / or the partial beams preferably have a linear cross-section, so that the object 4 is illuminated linearly by the respective partial beam.
[0065] The measuring device 1 can have a partial beam blocking device with a blocking element 15 for the controlled blocking of a partial beam of the partial beams, wherein the blocking element 15 is controllably movable, and in particular pivotable, into a beam path of the partial beam, in particular its irradiation section S1, S2, S3, so that the beam path is interrupted by the blocking element 15. This is shown by way of example for the first partial beam in Figs. 4 and 5.
[0066] The measuring device 1 can be implemented as part of a measuring system, wherein the measuring system has a measuring device base on which the measuring device 1 is mounted. It is advantageous if the measuring device 1 is rotatably connected to the measuring device base about an axis of rotation oriented orthogonally to the plane of the arrangement. The measuring device 1 can thus be rotated relative to the object 4 being measured. This is shown schematically in Fig. 6, where the measuring device 1 is rotated about the axis of rotation relative to the object 4 compared to the orientation of the measuring device 1 in Fig. 3. In this way, depending on the size of the wafer, the distance between regions of the object 4 being measured and regions of the measuring device 1 that are not located in the area of the light curtain can be varied by rotating the measuring device 1 relative to the measuring device base.Figure 7 shows an image 17 of a camera image taken with camera 3 of a lateral edge profile 16 of the wafer's edge region. The image 17 shows scattered light from the light curtain at the object 4 in a negative representation, or is a negative image 17a. The image 17 shows a scattered light fringe 18 formed by the scattered light, which runs along an edge profile of the edge profile 16, often referred to as the edge profile of the scattered light fringe 18. The edge profile of the scattered light fringe 18 usually corresponds to the edge profile 16. Typically, an edge region of the wafer is moved through the light curtain, usually with rotation of the wafer, in order to successively illuminate different areas of the edge region with the light curtain and to record an image 17 of each scattered light fringe 18 formed by the scattered light from the light curtain with camera 3.Based on the respective image 17 and its scattered light fringe 18, an edge profile 16 of the respective investigation area can be determined as described. In this way, changes in the edge profiles 16 between the investigation areas of the wafer can be determined by evaluating the recorded scattered light fringe 18. A method for edge profile determination can be practically implemented in the above manner. Typically, the images 17 are acquired such that the investigation areas corresponding to the images 17 are spaced apart from each other by a specific, preferably equidistant, polar angular distance along a circumferential direction of the wafer, particularly the edge region. For example, the investigation areas can be spaced apart from each other by a polar angular distance of 1° along the circumferential direction.
[0067] Based on the images 17 of the inspection areas, which depict a respective scattered light fringe 18, an edge inspection can be performed to detect contamination and / or surface defects of the edge area. For this purpose, intensity distributions of the scattered light fringes 18 can be compared and / or graphically represented. Fig. 8 shows an exemplary flow diagram of the procedure for edge inspection of the wafer. In a step U1, particularly as described above, inspection areas spaced apart from one another along the circumferential direction of the wafer are irradiated successively by the light curtain, and an image 17 of a scattered light fringe 18 formed by the scattered light of the light curtain is recorded with the camera 3 in each case.In step U2, the respective image 17 is evaluated, whereby edge positions representing the edge path are each assigned an intensity value based on pixels located above and below the edge position, which lie within a predefined clustering distance 19. The intensity values form the intensity distribution of the scattered light fringe 18 along the edge path. The intensity values of the edge positions of the respective scattered light fringe 18 can be stored, for example, in the form of a vector or a data series. Figure 9 shows an example of an image 17 of a scattered light fringe 18 taken with the camera 3, where the clustering distance 19 is represented by dashed lines on both sides of the edge path of the scattered light fringe 18, often referred to as cluster strips. In contrast to the negative representation in Figure 7, the image 17 in Figure 9 represents a normal image or a positive image 17b.The edge positions can be points of the edge profile determined for the respective image 17 or the respective investigation area. Accordingly, it is advantageous if the respective edge profile is determined as described in this document before determining the intensity distribution, in particular the intensity values, of the respective image, usually as part of step U2.
[0068] In step U3, the intensity distributions of the scattered light fringes 18, represented by the intensity values, are graphically displayed using a scatter plot. The scatter plot shows the intensity distributions along the edges of the scattered light fringes 18 side by side. To relate the intensity distributions of the scattered light fringes 18 to each other, it is practical to choose a point in the middle of a lateral side of each scattered light fringe 18 as a corresponding reference point. Figure 10 shows an example of such a scatter plot. Preferably, one dimension of the scatter plot indicates the edge positions, and another dimension indicates the position of the investigation areas on the wafer corresponding to the images, for example, using polar angles that identify the respective investigation areas. In the scatter plot of Figure 10, the edge positions are shown.Figure 10 shows the edge positions, labeled PP, on the y-axis and the polar angles, labeled UP, on the x-axis. The scatter plot in Figure 10 shows the intensity values of the edge positions of the scattered light fringes 18, plotted column by column. At the zero point of the y-axis of the scatter plot in Figure 10 are edge positions corresponding to the midpoint of each of the lateral sides of the wafer. The edge positions of the top side of the wafer are shown in the positive segment of the y-axis, and the edge positions of the bottom side of the wafer are shown in the negative segment of the y-axis. The intensity values are typically indicated in the scatter plot using a light-dark scheme and / or a color scheme.In this way, the scatter plot represents a two-dimensional surface in which contamination and / or surface defects of the wafer's edge region can be detected and assessed based on the displayed intensity values. Steps U2 and U3 are typically performed using a computer-implemented evaluation procedure.
[0069] In this way, a measuring device 1 for edge profile investigation, as well as the determination of an edge profile 16 and an edge inspection of a wafer, in particular its edge region, as a measuring object 4, can be implemented with high practicality. In particular, it is possible to detect and locate irregularities and / or defects on the surface of the wafer, especially its edge region, with great practicality and low effort.
Claims
Patent claims 1. Measuring device (1) for edge profile examination, in particular edge profile determination and / or edge inspection, of a typically disc-shaped measurement object (4), in particular wafers, wherein the measuring device (1) comprises a lighting device (2) and a camera (3) to form a light curtain with laser light in a measurement plane (M) with the lighting device (2), wherein a recording direction (A) of the camera (3) is oriented transversely, in particular orthogonally, to the measurement plane (M) in order to record with the camera (3) a scattered light from the light curtain on the measurement object (4) when the measurement object (4) is arranged transversely to the light curtain, characterized in that the lighting device (2) comprises a laser light source (5) and a beam splitter (11) to separate a source laser beam (L) emitted by the laser light source (5) into several partial beams and to direct them accordingly.that the partial beams from different directions form the light curtain in order to illuminate the object being measured (4) from different directions with the partial beams.
2. Measuring device (1) according to claim 1, characterized in that the lighting device (2) is designed to form the partial beams each with a linear light beam cross-section for irradiating the object being measured (4).
3. Measuring device (1) according to claim 1 or 2, characterized in that the partial beams can be directed by the beam splitter device (11) in such a way that the object being measured (4) is illuminated by the partial beams on a top and bottom side and preferably on a lateral side of the object being measured (4), in particular in a linear fashion.
4. Measuring device (1) according to one of claims 1 to 3, characterized in that the respective partial beam forms the light curtain with an irradiation section of the partial beam, wherein the partial beams can be directed by the beam splitter device (11) such that the irradiation sections (S1, S2, S3) are preferably arranged coplanarly in a common plane.
5. Measuring device (1) according to claim 4, characterized in that the partial beams can be directed by the beam splitter device (11) such that the irradiation section (S1) of a first partial beam of the partial beams lies in the arrangement plane and the irradiation section (S2) of a second partial beam of the partial beams, and preferably the irradiation section (S3) of a third partial beam of the partial beams, is each aligned at an orthogonal orientation angle of less than 80°, preferably between 55° and 70°, to the arrangement plane.
6. Measuring device (1) according to one of claims 1 to 5, characterized in that the beam splitter device (11) has one or more beam splitters (13), in particular Littrow prisms, to separate the source laser beam (L) into the partial beams with the beam splitters (13).
7. Measuring device (1) according to claim 6, characterized in that the beam splitter device (11) is configured to split the source laser beam (L) into partial beams, such that one or more of the partial beams are deflected and one of the partial beams retains an orientation with which the source laser beam (L) reaches the beam splitter device (11).
8. Measuring device (1) according to one of claims 1 to 7, characterized in that the measuring device (1) has a partial beam blocking device for controlled blocking of one or more of the partial beams, so that the respective partial beam no longer contributes to the formation of the light curtain when blocked with the partial beam device.
9. Measuring device (1) according to one of claims 1 to 8, characterized in that several apertures (14), in particular slit apertures, of the measuring device (1) are arranged one behind the other between the laser light source (5) and the beam splitter device (11), so that the source laser beam (L) is passed through the apertures (14) in order to reduce scattering reflections of the source laser beam (L) and / or to limit a cross-section of the source laser beam (L).
10. Measuring device (1) according to one of claims 1 to 9, characterized in that the camera (3) has an optical deflection device, in particular a deflection prism (8), for deflecting the camera beam path along a camera recording beam path in the direction of a section of the object to be recorded with the camera (3) downstream of the lens (7), such that an optical axis of the lens (7) and the recording direction (A) form an angle between 85° and 110°, preferably 90°.
11. Measuring device (1) according to one of claims 1 to 10, characterized in that the light curtain is formed with the laser light of exactly one laser light source (5).
12. Measuring device (1) according to one of claims 1 to 11, characterized in that the object being measured (4) is an edge region of a semiconductor wafer.
13. Measuring system comprising a measuring device (1) according to one of claims 1 to 12, characterized in that the measuring system has a measuring device base on which the measuring device (1) is mounted, wherein the measuring device (1) is movably connected to the measuring device base relative to the measuring device base, in particular guided.
14. Method for determining the edge profile of a typically disk-shaped measurement object (4), in particular a wafer, wherein a light curtain formed with laser light is created in a measurement plane (M) by means of an illumination device (2), wherein a measurement object (4) arranged transversely to the light curtain is illuminated by the light curtain, wherein a camera (3) in a recording direction (A) transverse, in particular orthogonal, to the measurement plane (M) records scattered light from the light curtain at the measurement object (4) and the edge profile of the measurement object (4) is determined based on the recorded scattered light, characterized in that the illumination device (2) comprises a laser light source (5) and a beam splitter device (11), wherein a source laser beam (L) emitted by the laser light source (5) is separated into several partial beams by means of the beam splitter device (11), wherein the partial beams are directed in such a manner thatthat the partial beams from different directions form the light curtain in order to illuminate the object being measured (4) from different directions with the partial beams.
15. Method according to claim 14, characterized in that the object to be measured (4) is arranged in an arrangement plane, wherein the measurement plane (M) is oriented transversely, in particular orthogonally, to the arrangement plane.
16. Method for edge inspection of a typically disk-shaped object to be measured (4), in particular wafers, wherein a light curtain formed with laser light is created in a measurement plane (M) by means of an illumination device (2), wherein an object to be measured (4) arranged transversely to the light curtain is illuminated by the light curtain, wherein a camera (3) in a recording direction (A) transversely, in particular orthogonally, to the measurement plane (M) records scattered light from the light curtain at the object to be measured (4), characterized in that the illumination device (2) comprises a laser light source (5) and a beam splitter device (11).wherein a source laser beam (L) emitted by the laser light source (5) is split into several partial beams by means of the beam splitter device (11), wherein the partial beams are directed such that the partial beams from different directions form the light curtain in order to irradiate the object (4) from different directions with the partial beams, wherein different areas of the object (4) are successively irradiated by the light curtain, in particular by moving the object (4) through the light curtain, and an image (17) of a scattered light fringe (18) formed by the scattered light is recorded in each case, after which intensity distributions of the scattered light fringes (18) are compared and / or graphically represented.
17. Method according to claim 16, characterized in that for the respective image an intensity distribution of the scattered light fringe (18) of the image (17) is determined along an edge profile of the scattered light fringe (18).
18. Method according to claim 17, characterized in that for the respective image (17) along the edge profile of the scattered light fringe (18) of the image (17), edge positions representing the edge profile are each assigned an intensity value based on the intensities of several pixels of the image (17) located above and below the edge position in the vertical direction of the edge profile, preferably according to a clustering distance (19) assigned to the edge position, in order to form the intensity distribution of the scattered light fringe (18) along the edge profile with the intensity values.
19. Method according to one of claims 16 to 18, characterized in that the intensity distributions of the scattered light fringes (18) are graphically represented with a scatter diagram, often referred to as a scatter intensity map, in order to represent intensity fluctuations along a surface of the object being measured (4), wherein preferably the intensity distributions along the edge profiles of the scattered light fringes (18) of the images (17) are shown side by side in the scatter diagram.