Camera system and method of imaging and navigating object in microscope system

Abstract

The invention relates to a camera system for use in a microscope system wherein the camera system is adapted to take an optical image of an object. A camera system includes a camera having an image field, where the image field of the camera includes at least a first sub-image field and a second sub-image field. Furthermore, the camera system comprises an optical mirror element having a mirror surface, the mirror element being able to be arranged in the microscope system. The camera system is configured such that a first view of the object can be imaged to a first sub-image field of the camera via the reflective mirror, and a second view of the object can be imaged to a second sub-image field.

Description

Technical Field

[0001] The invention relates to an apparatus and a method for optically imaging an object in a plurality of views, wherein the object is provided in a microscope system. The optical images produced can be used to move the object (which can be a sample to be investigated or a component of the microscope system) without collision. Furthermore, these images can be used to determine the position of a site of interest on the sample so that it can be made available for more precise investigation with the microscope system. Background Art

[0002] The microscope system may be, for example, an optical microscope, an X-ray microscope, a scanning electron microscope (SEM), a ion microscope (FIB), or a combined FIB-SEM device.

[0003] With the aid of a scanning electron microscope (SEM) or an ion microscope (FIB), an object positioned below the objective of the microscope can be imaged by interaction with charged particles (electrons or ions). The object can be, for example, a sample under the microscope, but can also be a sample stage of the microscope system or other components of the microscope system, such as a micromanipulator.

[0004] Typically, particle beam microscopes are only able to image relatively small fields of view. However, relatively large samples (e.g., entire wafers) are often to be investigated and therefore arranged in the field of view of the microscope system. Therefore, the challenge is to precisely position the part of interest of the object relative to the objective of the microscope system.

[0005] This becomes difficult because the object to be imaged in an electron microscope or ion microscope is arranged in a closed sample chamber under vacuum conditions. In order to ensure electrical and radiation shielding, the walls of the sample chamber are generally made of metal, so that the user cannot see the interior of the sample chamber.

[0006] However, X-ray microscopes or optical microscopes may also be equipped with a light-tight sample chamber in which the sample is provided during investigation under the microscope. Therefore, even in these microscope systems it is difficult for the user to navigate the sample or the sample stage on which the sample is arranged in the sample chamber without direct visual contact with the user.

[0007] Collisions between the sample to be investigated and various microscope components such as objective lenses, detectors, manipulators or gas injection systems should be prevented at all costs, since these could result in damage to the sample and / or the microscope.

[0008] If the geometry of the sample is known or has been detected in advance, collisions can be avoided by precalculating possible collision events with the aid of a 3D model. However, the geometry of microscopic samples is usually not precisely known and detection by 3D scanning methods is in most cases time-consuming and expensive.

[0009] Although in many applications it is also conceivable to achieve an exact positioning of the sample with the aid of a correlation scheme. For example, data on the sample may already exist from other microscope types in which the sample has previously been investigated. Or data on the sample may exist by panoramic recording of the sample surface, the position of which is precisely known. However, suitable correlation systems are not available to every user. In addition, for many applications it is too time-consuming to perform a preliminary detection of the sample.

[0010] In electron and ion microscopy, two different solutions are usually used for navigation and collision prevention.

[0011] So-called chamberscope camera solutions are known, in which a camera (chamberscope camera) arranged at or in the sample chamber allows a view of the interior of the chamber in combination with a lighting device that is also installed.

[0012] In this case, the sample is usually imaged in a side view, so that the user can, for example, follow the displacement of the sample stage in order to avoid collisions.

[0013] However, in the simplest embodiment, the user must always see the camera image during any movement of the sample stage (and the sample accommodated thereon), but also during the movement of other displaceable microscope components (e.g. detectors, manipulators, gas injection systems, vacuum diaphragms). Collisions are avoided, but also a rough positioning of the sample is performed only based on the camera image and the user's experience.

[0014] In addition, modern methods offer the possibility of identifying samples by means of image recognition methods or artificial intelligence (KI) to assist the user. However, these methods use the same images of a chamberscope camera as a basis.

[0015] Furthermore, for navigation, a so-called navigation camera can be used, with the aid of which a location of interest on the sample surface can be positioned in a targeted manner in the field of view of the microscope. For this purpose, a top view image of the sample is recorded with the navigation camera.

[0016] The resulting top-view image is used to determine the position of a certain point on the sample surface. In this case, either the camera position is known or the image is linked to the sample stage coordinates using known points or markings. The sample can then be navigated in the sample chamber using the overview image.

[0017] Typically, the user is shown at which point on the photograph the field of view of the microscope is currently located. By selecting a position on the photograph, the sample is moved (by moving the sample stage) to a corresponding position relative to the microscope objective.

[0018] The disadvantage of the solution mentioned is that at least two cameras are required (a navigation camera for recording the top view, a chamberscope for recording the side view). This results in high costs and little free space in the sample chamber, thus generally limiting the mobility of the displaceable component.

[0019] The following may be considered relevant prior art:

[0020] DE 10 2017 201 706 A1 (Berger)

[0021] EP 2793069 A1 (Gaiduk et al.)

[0022] US11239051 B2(Yoshihara&Oominami)

[0023] DE 11 2015 006 181 B4 (Ishizawa et al.)

[0024] DE 10 2021 109 820 B3(Diemer).

[0025] DE 10 2017 2017 06 A1 describes an imaging unit for imaging an object in a particle beam device. The illumination unit has two switching states, by which the object can be illuminated with light having two different spectral ranges.

[0026] EP 2793069 A1 describes a digital microscope having an observation sensor for observing a sample.

[0027] US Pat. No. 11239051 B2 discloses a particle beam device, in which the same field of view can be observed by means of the particle beam device and a camera.

[0028] DE 112015006181 B4 describes that a CCD camera captures an image of a sample stage, wherein a measurement reference point is displayed on the captured image. In addition, DE 10 2021 109 820 B3 discloses how to capture an optical image with a navigation camera.

[0029] A disadvantage of the solutions mentioned is that the sample can accordingly only be imaged from one viewing angle. Summary of the invention

[0030] The object of the present invention is to specify a camera system in which at least two different views of an object located in a sample chamber of a microscope system can be imaged using only one camera.

[0031] This object is achieved by a camera system having the features of claim 1. Dependent claims 2 to 9 provide advantageous refinements.

[0032] Furthermore, the object is to specify a method by means of which a plurality of views of an object can be recorded with one optical camera. This object is achieved by the method according to claim 10 and the dependent claims 11 to 13.

[0033] Furthermore, the present invention comprises a computer program product according to claim 14 which causes a microscope system to carry out the method according to the present invention.

[0034] The invention is based on the finding that, using a mirror element and a camera having at least two image regions (referred to below as sub-image fields), two different views of the same object can be recorded with just one optical camera.

[0035] A sub-image field is understood to be a region of an image sensor (camera sensor) that includes a plurality of pixels. For example, a sub-image field may include ten pixels (e.g. 1 pixel×10 pixels or 2 pixels×5 pixels). It is particularly advantageous if a sub-image field includes more than ten pixels.

[0036] The image sensor of the camera thus has at least two sub-image fields, wherein one view of the object is imaged directly into one sub-image field, while another view of the object is imaged via a mirror element into another sub-image field. Thus, for example, a top view and a side view of an object can be recorded simultaneously or successively with the same camera.

[0037] Importantly, the camera can therefore detect at least two different fields of view, which are imaged via different beam paths. That is, the imaging beam is split into at least two sub-beams. The beam paths of the imaging sub-beams differ in that on a first beam path, the sub-beam is reflected at a reflective element, so that the first sub-beam is deflected to another direction. That is, this means that the imaging beam imaged to the first sub-image field of the image sensor via the first beam path first propagates in a first direction and propagates in a second direction after being reflected.

[0038] However, the beamlets of the second beam path are not deflected, so that the initial direction of the second beamlets is maintained.The direction of the beamlets on the second beam path generally corresponds to the first direction of the beamlets on the first beam path.

[0039] However, it is also conceivable that the camera system comprises a plurality of reflective elements and the image sensor correspondingly comprises a plurality of sub-image fields, so that more than two sub-beams can be imaged via different beam paths.

[0040] The sub-image fields can be arranged one after the other or overlap one another in the image field of the image sensor. It is also conceivable that (depending on the specific application) parts of the image field remain unused. This has the advantage that the amount of data that must be processed and transmitted can be reduced.

[0041] The object to be imaged can be a microscopic sample, i.e. a sample to be investigated with the aid of the microscope system used, i.e. a sample to be investigated, for example, with an electron microscope or an ion microscope. For this purpose, the sample is usually provided in a sample chamber of the microscope system. However, the object to be imaged with the aid of the camera system according to the invention can also be a construction unit of the microscope system. That is, in the sample chamber there are usually functional, movable construction units (e.g. a sample stage, a micromanipulator, a displaceable detector or a gas injection system), but also static construction units (e.g. an objective of the microscope system). It is particularly important to observe the construction units in order to avoid collisions.

[0042] The camera used is advantageously an optical camera. To illuminate the sample chamber, a light-transmitting window can be provided in the wall of the sample chamber or a special lighting unit can be used, which is arranged inside the sample chamber. In principle, the wavelength range of the illumination should be coordinated with the sensitivity range of the image sensor of the camera.

[0043] For example, an infrared light source can be used, which emits infrared light with a wavelength of, for example, 950 nm. The infrared light is used to illuminate the object, so that the object can be imaged with the aid of a camera sensitive to infrared light. However, only black and white images can be produced by infrared illumination.

[0044] However, in order to obtain a color image, an illumination unit that radiates visible light can also be used. Thus, for example, a white light source can be used, by which the object is illuminated with white light. A color image of the object can then be generated with the aid of an image sensor of a camera that is sensitive to the corresponding wavelength range.

[0045] Advantageously, the respectively acquired image of the object can be displayed on a display of the microscope system and, if necessary, can also be stored by means of an evaluation and control unit.

[0046] The camera system according to the invention can be used in different types of microscope systems. The microscope system can be, for example, a scanning electron microscope (SEM), an ion microscope (FIB) or a combined FIB-SEM device. However, it is also conceivable that the camera system is used in an optical microscope or an X-ray microscope. The use of a camera system is always particularly meaningful when the microscope system has a light-tight sample chamber, so that the user cannot directly observe the sample and / or construction units that are at risk of collision.

[0047] The camera used can be arranged in different places, for example inside or outside the sample chamber or at or in a wall of the sample chamber.

[0048] It is important here that the camera is arranged so that it sees the reflector surface with a part of its field of view. Another part of the field of view sees next to the reflector surface. The field of view of the camera is thus divided into two areas, which can be assigned different functions. Thus, one area can be operated as a chamberscope camera, while the other area is provided for the navigation camera. It has proven to be advantageous if the reflector surface is arranged obliquely to the optical axis of the camera, for example at an angle of 45°.

[0049] The mirror elements of the camera system may be arranged at different positions on one of the imaging beam paths.

[0050] However, in addition to the basic function of image recording, the mirror element can also be used to guide light in a targeted manner when illuminating an object, more precisely a sample under a microscope. For this purpose, the mirror element can also be designed so that it is part of the imaging beam path and part of the illumination beam path by which the sample is illuminated.

[0051] In another embodiment, multiple mirror elements are used in combination with dividing the image field into corresponding multiple sub-image fields, thereby enabling views of the object from more than two different directions simultaneously.

[0052] The invention also includes a method for recording an optical image of an object in a microscope system, wherein the microscope system includes a camera system according to the invention. At least two different views of the object are recorded with the aid of the camera system and imaged onto respective sub-image fields of the image sensor used. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In the following, embodiments of the invention will be described with reference to the drawings. Reference is therefore also made to all of the above and following descriptions for explaining the components.

[0054] FIG. 1 schematically shows a camera system according to the invention, which can be used to detect a field of view which is divided into two sub-fields of view A and B. FIG.

[0055] Figure 1a Two sub-fields of view A and B are shown in the same figure. For better understanding, these sub-fields of view are again Figure 1b and Figure 1c Shown separately: Figure 1b The beam path of the first sub-field A is shown, and Figure 1c The beam path of the second sub-field of view B is shown.

[0056] Figure 2a and Figure 2b An exemplary application scenario of a camera system is schematically shown, in which subfields of view A and B are imaged at different positions of the sample stage.

[0057] Figure 3a , Figure 3b and Figure 3c Different arrangements of the camera relative to the sample chamber and relative to the objective of the microscope system are shown by way of example.

[0058] Figure 4 (including sub-images Figures 4a to 4f ) show different embodiments of a camera system, showing different exemplary arrangements of mirror elements.

[0059] Figure 5a and Figure 5b Embodiments are shown that use multiple mirror elements to enable imaging of more than two views of an object.

[0060] Figure 6 An embodiment is shown in which the microscope system is designed as an X-ray microscope.

[0061] Figure 7a and Figure 7b Two specific embodiments are shown in which the camera system is used in an optical microscope.

[0062] Figure 8 An example of a combined FIB-SEM device in which the camera system of the present invention can be used is schematically shown.

[0063] Fig. 9 A flow chart of the method according to the invention is shown, by which at least two different views of a sample under a microscope are recorded with a camera. DETAILED DESCRIPTION

[0064] FIG. 1 shows a first embodiment of a camera system according to the present invention.

[0065] The camera system is configured to be used in the sample chamber 4 of the microscope system 10. Figure 1a to Figure 1c The microscope system and the camera system are shown on the left side of the figures, and the image sensor 160 is shown schematically on the right side, which is located inside the camera 1.

[0066] In the embodiment of Fig. 1, the microscope system 10 is designed as a particle beam microscope, more precisely as a scanning electron microscope (SEM). Correspondingly, the microscope system 10 comprises an electron beam column 3, in which a beam of charged particles (electron beam) can be generated in order to image a sample 7 to be studied with a microscope. The electron beam column 3 has an optical axis 14, along which the charged particles move.

[0067] The microscope system 10 comprises a sample chamber 4 in which vacuum conditions prevail during operation. A sample stage 5 is arranged in the sample chamber 4 on which a sample holder 6 with a sample 7 can be received.

[0068] The camera system according to the invention comprises a camera 1 having a camera lens 2. With the aid of the camera 1, which has an optical axis 17, an optical image can be recorded from the interior of a sample chamber 4.

[0069] Furthermore, the camera system comprises at least one mirror element 8, which is advantageously arranged inside the sample chamber 4. The mirror element 8 has a mirror surface 9, which is arranged in the imaging beam path of the camera system.

[0070] It is particularly advantageous if the mirror surface is at a defined angle α relative to the optical axis 17 of the camera. Thus, the value of the angle α may be 10° to 90°, preferably 30° to 90°, so that the first view of the object and the second view of the object differ from each other. In a particularly advantageous embodiment, the value of the angle α is substantially 45°.

[0071] In order to image the sample 7 in the field of view of the camera, the imaging beam is diverted from the sample 7, through the beam path of the camera system, to the camera lens 2. After passing the camera lens 2, the imaging beam is diverted to the image sensor 160 inside the camera 1. The image sensor 160 comprises an image field 16, into which the field of view is imaged.

[0072] It is important that the image field 16 of the camera 1 is divided into at least two sub-areas, namely a first sub-image field A' and a second sub-image field B'. In the exemplary embodiment shown here, the sub-image fields A' and B' are imaged successively to the image sensor 160. However, the present invention is not limited to this arrangement. It is also conceivable that the sub-image fields intersect or that certain areas of the image sensor remain unused.

[0073] By providing a plurality of sub-image fields A', B' on the image sensor, the field of view of the camera can also be divided into two sub-areas, namely, sub-viewing fields A and B, which can be imaged independently of each other to corresponding sub-image fields A' and B'. Therefore, two different views of the sample 7 (i.e., sub-viewing fields A and B) can be imaged independently of each other ( Figure 1a ).

[0074] To better understand the beam path (which helps to achieve these two views), Figure 1b and Figure 1c In each case only the imaging of one of the two partial fields of view and the respectively associated beam path are shown.

[0075] Figure 1b The beam path of the first sub-field of view A is shown. The beam 12 of the first sub-field of view A is deflected to the reflective mirror 9 and reflected there. As a result, the sample 7 is imaged, for example, in a side view to the first sub-field of view A' of the image sensor 160. That is, the reflective mirror 9 is arranged on the beam path of the first sub-field of view A. That is, in Figure 1b In an arrangement of , the first sub-field of view A provides a side view of the sample 7. It is also conceivable that in this sub-view also further objects (eg the sample support 6 or also the sample support 6 and the sample stage 5) are imaged in a side view.

[0076] Figure 1c The beam path 13 of the second sub-field of view B is shown. Here, the beam 13 of the beam path extends without the involvement of mirrors. The second sub-field of view B provides a top view of the sample 5 imaged into the second sub-field B′ of the image sensor 160 .

[0077] Generally speaking, the first view and the second view of the object are different from each other.

[0078] That is, different views of an object can thus be generated with a camera system. Here, the viewing angle (eg, top view, side view or any other view) is correspondingly related to the exact orientation of the camera lens, the mirror element and the imaged object relative to each other.

[0079] It has proven to be particularly advantageous if the top view corresponds to a view of the microscope system in which the particle beam images the sample. It is also advantageous if the side view is oriented approximately at a right angle to the top view. This can be achieved, for example, by aligning the mirror surface at an angle of approximately 45° (α≈45°) relative to the optical axis of the camera.

[0080] The sample chamber 2 and the object to be imaged (in this example, the sample 7) can be illuminated by an illumination system. The wavelength of the light source 15 used and the sensitivity range of the image sensor should be coordinated with each other. The illumination wavelength can be, for example, in the visible spectrum (350 nm-800 nm) or also in the infrared range (800 nm-1500 nm).

[0081] The images of the sub-viewing areas A and B can be selectively captured simultaneously or sequentially by the camera 1. In any case, the images of the sub-viewing areas are captured independently of each other.

[0082] However, the present invention is not limited to the image sensor 160 including two sub-image areas A' and B'. Instead, the image sensor 160 may be divided into three or more sub-image areas, so that three or more views of the object can be imaged.

[0083] It has proven to be particularly advantageous if the mirror element 8 is provided with an electrically conductive surface in order to prevent charging which could be caused by charged particles of the particle beam microscope. For this purpose, a metallic mirror or a mirror with a metallic reflective layer can be used. It is also conceivable to use an optically transparent coating, for example a coating formed of indium tin oxide.

[0084] Reflective element 8 can be designed as a plane mirror or a curved mirror, for example, as a convex mirror, a concave mirror or a Fresnel mirror or also as a prism. It is also conceivable that a suitable surface of a component of a microscope system, for example a conical side wall of an objective lens, is used as a reflective element.

[0085] A particular advantage of using a curved mirror is that it allows image errors to be corrected. In addition, the field of view can be increased by selecting a suitable curvature.

[0086] In addition, the reflective element can be combined with other optical elements, for example with polarization filters, wavelength filters or also with special coatings. Such coatings can be hard coatings, as protection against mechanical damage or as anti-reflection coatings, for example.

[0087] As shown in Figure 1, the images can be taken with a constant sample stage position and a constant sample position. However, it is also conceivable to perform imaging of sub-viewing regions A and B with different sample stage positions, optimized for this purpose, as is exemplarily shown in Figure 2.

[0088] Typically, the sample stage 5 is displaceable in multiple directions. For example, a so-called 5-axis sample stage generally has three lateral movement axes (X, Y and Z) as well as a rotation axis (R) and a tilt axis (T). By moving the sample stage 5, the received sample 7 can be correspondingly moved and oriented relative to the incident particle beam (depending on the respective application case).

[0089] An image of the sub-viewing area A is captured at the first sample stage position and imaged as a sub-image field A' to the image sensor 160 ( Figure 2a ). The sub-image field A' is arranged here at a first position 19 within the image field 16. In this example, the imaging of the sub-viewing region A provides a side view of the sample 7, the sample holder 6 and the sample stage 5. The imaging is performed by directing the imaging beam through the mirror element 8.

[0090] Then the top view of the sample should be imaged. To this end, the sample stage 5 together with the sample holder 6 and the sample 7 is shifted to the second sample stage position ( Figure 2b ). The second sample stage position is optimized for top view imaging, since the sample 7 is now positioned below the camera lens 2. The sub-viewing area B can now be imaged by directing the imaging beam from the sample 7 directly to the camera lens 2, so that a sub-image field B' is generated on the image sensor 160. Here, the sub-image field B' is arranged at the second position 20, which is oriented so that it intersects the first position 19. That is, the sub-image fields A' and B' are therefore not arranged side by side in the image field 16 of the image sensor 160, but rather overlap.

[0091] In principle, it is also conceivable that more than two sub-image fields overlap. In this case, the sub-image fields do not necessarily have to fill the area of ​​the image sensor, but the remaining area 18 of the image sensor can remain unused. Advantageously, the amount of data to be transmitted can be reduced. It is also conceivable to further process only the interesting part of the image recorded by the camera instead of the entire image.

[0092] The sub-image fields may assume any shape, such as rectangular, circular, hexagonal or trapezoidal. It is also conceivable that the shape of the sub-image fields follows the shape of the sample being imaged.

[0093] It is not necessary to record the optical images in the discrete sample stage positions shown in Fig. 2. Rather, it is also possible to record the images with the sample stage in any selected sample stage position.

[0094] Furthermore, it can be advantageous to adapt the sub-image field of the camera to a selected position of the sample stage.The sub-image field can be selected by using image recognition, by presetting or by selection by a user.

[0095] 3 shows different installation positions of the camera system. In particular, the arrangement of the camera 31 relative to the particle beam column 33 and the objective 30 can be different.

[0096] The sample 37 is held on the sample stage 35 by means of a sample holder 36. Figure 3a to Figure 3c The reflector element 38 is always shown at the same position. However, it is conceivable that the reflector element 38 is arranged at another position, such as is shown in FIG. 4 .

[0097] One possibility for arranging the camera in a microscope system is to place the camera 31 and the camera lens 32 completely outside the sample chamber 34 ( Figure 3a ). A viewing window 39 is provided in the wall of the sample chamber 34, through which the optical imaging beam path passes, so that imaging of the chamber interior is possible. In this arrangement, it is advantageous that the camera 31 is not installed in a vacuum region and is therefore not necessarily suitable for a vacuum. In addition, the power supply and any required cooling of the camera 31 can be designed to be simpler.

[0098] Alternatively, the camera 31 may be arranged partially in the sample chamber 34, that is, the camera 31 is arranged in a wall of the sample chamber 34, such as Figure 3b As shown in .

[0099] Another possibility is to arrange the camera 31 in the sample chamber, such as Figure 3c It is also conceivable that the camera 31 is arranged at the bottom of the sample chamber or at any position in the sample chamber, for example, also tilted ( Figure 3c ) on the outer surface of the sample chamber.

[0100] Figure 4 (including sub-images Figures 4a to 4f ) shows that the mirror element 48 can be arranged in different ways in the sample chamber. In this case, the camera is not shown accordingly.

[0101] In principle, the reflector element can be fixedly mounted ( Figures 4a to 4d ) or may be removably mounted ( Figure 4e and Figure 4f ).

[0102] However, even a fixedly mounted mirror element can be moved by attaching it to a movable component, for example a sample stage 45 , and moving it by moving the sample stage.

[0103] Figure 4a4 shows how two reflector elements 48, 49 are fixedly arranged on the chamber wall 41. The two reflector elements 48, 49 are arranged on the upper wall of the sample chamber 44. However, it is also conceivable that the reflector elements are arranged on the lateral chamber walls and / or the chamber bottom of the sample chamber ( Figure 4b ).

[0104] In most cases, the sample chamber 44 is more or less shaped as a cube or a cube, so that it is defined by four side walls, an upper wall and a lower wall. In the example of Fig. 4, the upper wall (also referred to as the chamber top) is that chamber wall with which the particle beam column 43 is in flange connection. The lower wall (also referred to as the chamber bottom) is that chamber wall arranged opposite to the particle beam column 43.

[0105] Alternatively, the mirror element 48 may be fixedly mounted at the sample stage 45 ( Figure 4c ). Since the sample stage 45 is generally designed to be displaceable, the position of the mirror element 48 can be changed by moving the sample stage 45 .

[0106] It is also conceivable that the mirror element 48 is arranged on the sample holder 46 ( Figure 4d ), wherein the sample holder 46 can be received on the displaceable sample stage 45. Thus, the mirror element 48 can be brought to the desired position by moving the sample stage 45. Here, the mirror element 48 can be specially adapted to the type of sample holder 46.

[0107] The sample holder 46 is understood to be a receiving device which can receive one or more samples 47 on the one hand and is designed to be mounted on the sample stage on the other hand. That is, the sample holder is such that the sample 47 is not necessarily directly received on the sample stage. As indicated in FIG. 4 , it is in principle conceivable that not only one sample but several or more individual samples 47 are provided on the sample holder 46.

[0108] However, the reflector element 48 can also be designed to be movable itself. For example, the reflector element 48 can be arranged on the lateral chamber wall, such as Figure 4e Here, the mirror element may be provided with a retraction mechanism 42 or an operator (not shown).

[0109] Alternatively, the reflector element 48 can be designed to be movable in that it comprises a pivoting or rotating mechanism 50. It can be particularly advantageous here if the reflector element is fastened at the top of the sample chamber ( Figure 4f ) and can adopt a first orientation and a second orientation. In the case of the first orientation, the reflector element can, for example, remain in the beam path (working position). In the second orientation, the reflector element can be outside the beam path (rest position).

[0110] The design of the reflector element with the described mechanism has the advantage that the available space in the sample chamber can be optimally utilized. In addition, possible interference with other work processes to be performed with the microscope system is kept as small as possible.

[0111] In principle, the reflective element can be designed as a flat mirror or as a curved mirror, for example as a convex mirror, concave mirror or Fresnel mirror.

[0112] However, it is also conceivable that the reflective element is an optical element which enables reflective imaging, for example a prism.

[0113] Furthermore, it is conceivable that a suitable surface of the microscope system is used as the reflective element. This surface can be, for example, a reflective surface of a polished and / or coated objective of the microscope system.

[0114] Furthermore, the reflective element can be combined with further optical elements, for example with polarization filters, wavelength filters or also with special coatings.

[0115] As already mentioned, the division of the image field of the camera system is not limited to the two sub-image fields (top view and side view) described so far. Rather, it is also conceivable to use a plurality of mirror elements and to divide the image field into a corresponding plurality of sub-image fields in order to be able to realize a side view of the sample from a plurality of different directions.

[0116] This special embodiment using multiple mirror elements is shown in Fig. 5. The camera system comprises a camera 51 with a camera lens 52 and a first mirror element 58 and a second mirror element 580. In the situation shown in Fig. 5, a sample 57 is arranged in a sample chamber 54 of the microscope system.

[0117] exist Figure 5a In an embodiment of the present invention, a first imaging light beam is deflected from a sample 57 to a first mirror element 58 and then to a camera lens 52 on a first imaging beam path A, so that a first sub-image can be generated in a camera 51.

[0118] The first sub-image may be, for example, a first side view of the sample.

[0119] The second imaging beam is directed from the sample 57 via the camera lens 52 to the image field of the camera in a second beam path B. This allows a second sub-image of the sample to be generated, which corresponds to the front view.

[0120] The third imaging beam is deflected from the sample 57 to the second mirror element 580 on a third beam path C and subsequently guided to the camera lens 52. A third sub-image can thereby be generated in the camera, which can be a second side view of the sample.

[0121] exist Figure 5b In the exemplary, alternative embodiment shown in , a first light source 53 and a second light source 530 are used to better illuminate the sample 57. The mirror element is oriented such that it is arranged not only in the imaging beam path but also in the illumination beam path.

[0122] The light beam emitted by the first light source 53 is deflected toward the sample 57 via the first illumination beam path 55. A first reflector element 58 is arranged on the first illumination beam path 55, which deflects the light beam. At the same time, the first reflector element 58 is arranged on the first imaging beam path A, through which the sample 57 can be imaged in a first side view. In other words, the first reflector element 58 is adapted to be both part of the first illumination beam path and part of the first imaging beam path.

[0123] Figure 5b The embodiment of further comprises a second light source 530, which in a similar manner illuminates the sample 57 via a second illumination beam path 550. A second reflector element 580 is arranged on the second illumination beam path 550, which is also arranged on the second imaging beam path C. Therefore, the second reflector element 580 is adapted to be both part of the second illumination beam path and part of the second imaging beam path.

[0124] Furthermore, in this embodiment, the sample 57 can be imaged directly by means of the camera 51. The third beam path B comprises no mirror elements.

[0125] Figure 5b The embodiment has the advantage that the sample 57 can be illuminated from two different directions and can be observed and imaged from three different viewing angles.

[0126] 5 has the advantage that, for example, a fast 3D reconstruction of the sample contour can be achieved. This facilitates reliable navigation and collision avoidance when moving the sample.

[0127] It is also conceivable that not only a plurality of reflector elements but also other methods such as strip-shaped projection or point-shaped projection are used. For this purpose, a defined pattern can be projected onto the sample by means of a projection device, which can be captured with a camera and then processed into a 3D model.

[0128] Figure 6 An alternative embodiment of the camera system according to the invention is schematically shown, which camera system is configured to be used in an X-ray microscope.

[0129] The X-ray microscope comprises an X-ray source 63 which is adapted for generating an X-ray beam 68 for irradiating a sample 61. The X-ray beam 68 is deflected to the sample 61 by means of special X-ray optics 60.

[0130] The sample 61 is provided in a radiation-proof sample chamber 67 and is arranged on a movable sample stage 62. With the aid of an X-ray detector 66, an X-ray image of the sample 61 can be produced.

[0131] The camera system according to the invention comprises a camera 64 and an optical mirror element 65. The camera 64 and the mirror element 65 are arranged so that the sample 61 can be observed and imaged from two different viewing angles (sub-fields of view A and B), as has been described for the embodiments of Figures 1 to 5. Optionally, the X-ray microscope comprises an illumination unit 69.

[0132] FIG. 7 shows two further special embodiments of the camera system according to the invention used in an optical microscope.

[0133] exist Figure 7a In the embodiment of the present invention, the microscope system is designed as a relatively simple optical microscope without a sample chamber. Figure 7b The optical microscope includes a sample chamber 79 .

[0134] The sample 77 to be examined with an optical microscope is accordingly held on a sample stage 78 and positioned beneath the microscope-specific optical system 71 .

[0135] The user can observe the sample 77 in a magnified manner through the eyepiece 72 and take pictures of the sample with the help of a microscope camera (imaging camera) 73. Usually, the microscope system is equipped with a stand 74, by means of which the position of the optical device 71, the eyepiece 72 and the microscope camera 73 can be changed relative to the sample.

[0136] The camera 76 of the camera system according to the invention can also be arranged on the support 74, such as Figure 7a As shown in Figure 7a and Figure 7b In both embodiments shown in FIG. 7 , the mirror element 75 is arranged such that one sub-beam A is reflected, while the other sub-beam B is not guided through the mirror element.

[0137] Figure 7b It is also shown that there may be an illumination unit 80 to illuminate the sample 77. The illumination unit may include an infrared light source (wavelength of 800nm ​​to 1500nm) or visible light (wavelength of 350nm to 800nm).

[0138] Advantageously, the microscope system used (which is now an X-ray microscope ( Figure 6), optical microscope (Figure 7) or FIB-SEM combined equipment ( Figure 8 )) comprises an evaluation and control unit (not shown). The evaluation and control unit can execute a series of control instructions included in the computer program product. The control instructions cause the corresponding microscope system to execute the method according to the invention, which will Fig. 9 Described in detail in.

[0139] The embodiments of the camera system disclosed in FIGS. 1 to 5 can be used, for example, in a FIB-SEM combined device that will be Figure 8 Highlights in display.

[0140] Microscope system 600 includes two particle beam columns: an electron beam column 610 for generating an electron beam, and an ion beam column 810 for generating an ion beam. Both particle beams are directed toward a sample 750 to be processed, which is advantageously located at the point where the two particle beams coincide.

[0141] During operation of the combined FIB-SEM device 600, primary electrons are generated in the electron source 620, which are focused, parallelized or scattered along the optical axis 640 of the electron beam column by a focusing lens system 630 or a plurality of focusing lens systems 630, 650 and are cut by at least one aperture stop 660. The electron beam column 610 also comprises a deflection system 670, by means of which the primary electron beam can be guided in a grid-like manner through the sample 750, and an objective lens system 680, by means of which the primary electron beam can be focused onto the sample 750.

[0142] Furthermore, the combined FIB-SEM device 600 comprises an ion beam column 810 having an ion source 790, a deflection system 770, an aperture stop 820 and a lens system 760. The ion source 790 may be, for example, a liquid metal ion source (LMIS) operated, for example, with a gallium ion source.

[0143] Ions generated in the ion source 790 are accelerated along the optical axis 780 of the ion beam column, bunched, and focused onto the sample 750 with the aid of the objective lens system 800. The ions incident on the sample 750 can be used to remove material from the sample 750 and / or to image the sample 750. Optionally, the microscope system 600 can also have a gas injection system 720 for introducing process gases.

[0144] The combined FIB-SEM device 600 further includes at least one detector 700 for detecting interaction products of electrons and / or ions interacting with a sample 750 .

[0145] In order to provide a sample 750 to be investigated for investigation or processing with a microscope, the sample 750 is usually held by a sample holder 740. The sample holder 740 can be mounted on a sample stage 730. The sample stage 730 is arranged in a sample chamber 690 of the combined FIB-SEM device 600, in which vacuum conditions exist during operation.

[0146] It is particularly advantageous if the sample stage 730 is designed as a multi-axis sample stage, thereby providing a plurality of translational and rotational degrees of freedom of movement. This is the case, for example, when the sample stage 730 is designed as a five-axis sample stage comprising the translational axes X, Y and Z and the rotational axes R and T (tilt axis). The translational axes mentioned here are oriented perpendicular to each other.

[0147] That is, the sample 750 can be displaced with the multi-axis sample stage in three spatial directions X, Y and Z to change the positioning of the sample 750 in three-dimensional space. In addition, the spatial orientation, i.e. the orientation of the sample 750 relative to one or more optical axes of the microscope system, can be changed by rotating and / or tilting the sample 750 by means of the rotation axes R and T.

[0148] Furthermore, the microscope system 600 advantageously comprises an evaluation and control unit 710. The evaluation and control unit 710 can execute a series of control instructions included in a computer program product. By executing the control instructions, the microscope system 600 is prompted to perform the method according to the invention, which will Fig. 9 Described in detail in.

[0149] The method is used to capture an optical image of a sample under a microscope, wherein the sample is arranged inside a sample chamber of a microscope system. Fig. 9 A flow chart of the method according to the invention is shown. By means of the method at least two different views of a sample are recorded, using a mirror element and an optical camera.

[0150] The camera system used for the method and disclosed above is arranged in a microscope system which also includes a displaceable sample stage on which the sample can be received, as shown and described in Figure 2. Advantageously, there is also an illumination system by means of which the sample in the sample chamber can be illuminated.

[0151] First, a sample is provided on a sample stage (step S1 ).

[0152] Then, the sample stage is moved to arrange the sample at a first position relative to the camera and relative to the reflector element (step S2). For example, the sample is not arranged directly below the objective lens 2 of the camera 1, such as Figure 2a As shown in .

[0153] Then, a first view of the sample is captured with the camera by directing the imaging beam from the sample to the reflective element 8, where it is deflected and directed to the camera lens 2 of the camera 1 (step S3), as shown in FIG. Figure 2a (Sub-field of view A) is indicated in . It is particularly advantageous here if the mirror surface is arranged at an angle α relative to the optical axis of the camera, wherein the value of the angle α can assume a value of 10° to 90°, so that the first view of the object and the second view of the object differ from each other.

[0154] After passing through the camera lens 2, the imaging beam is diverted to the internal image sensor of the camera. The image sensor is divided into at least two sub-image fields, wherein the beam imaging the first view of the sample is imaged into the first sub-image field.

[0155] exist Figure 2a In the example of FIG. 5 , the first view is a side view of the sample 7 and the sample stage 5. However, the first view of the sample is not limited to the side view, but any other view may also be provided.

[0156] Then, the sample stage is moved to arrange the sample in a second position relative to the camera and the mirror element (step S4). Figure 2b As shown in , for this purpose the sample 7 can be arranged more or less below the camera lens 2 of the camera 1 .

[0157] In this arrangement, in step S5 a second view of the sample is captured with camera 1, wherein the imaging beam is not deflected by reflective element 8 but is directed directly to the image sensor in the camera. The beam, which also images the second view of the sample, is diverted to a second sub-image field of the image sensor.

[0158] exist Figure 2b In the example of FIG. 4 , the imaged viewing angle is a top view. However, it is also possible to select any other viewing angle, depending on the arrangement of sample, camera and mirror element relative to one another.

[0159] It is also conceivable that, in an optional further method step, optical distortions caused by curved surfaces in the imaging beam path are corrected by digital image processing.

[0160] In principle, the sub-image fields can be displayed and / or evaluated independently of one another. The sub-image fields can be read in and evaluated simultaneously or at different times. Alternatively, the image field is read out as a whole and split into individual sub-image fields in the image processing unit.

[0161] List of Reference Numerals

[0162] 1. Camera

[0163] 2 Camera Lenses

[0164] 3 Electron beam column

[0165] 4 Sample room

[0166] 5. Sample stage

[0167] 6 Sample holder

[0168] 7 Samples

[0169] 8 Mirror elements

[0170] 9 Reflective mirror

[0171] 10 Microscope System

[0172] 12 Beam of sub-field A

[0173] 13 Beam of sub-field B

[0174] 14 Optical axis of the electron beam column

[0175] 15 Light Source

[0176] 16 Image field of image sensor

[0177] 17 Optical axis of the camera

[0178] 18 Unused area of ​​the image sensor

[0179] 19 Position of sub-image field A

[0180] 20 Position of sub-field B

[0181] 160 Camera image sensor

[0182] A. The first sub-field of view

[0183] B The second sub-field of view

[0184] A' First sub-image field

[0185] B' Second sub-image field

[0186] α is the angle between the optical axis of the camera and the reflector surface

[0187] 30 Objective

[0188] 31 Camera

[0189] 32 Camera Lens

[0190] 33 Particle beam column

[0191] 34 Sample room

[0192] 35 Sample stage

[0193] 36 Sample holder

[0194] 37 samples

[0195] 38 first reflector element

[0196] 39 Windows

[0197] 41 chamber wall

[0198] 42 Withdrawal of institutions

[0199] 43 Particle beam column

[0200] 44 Sample Room

[0201] 45 Sample stage

[0202] 46 Sample holder

[0203] 47 samples

[0204] 48 first reflector element

[0205] 49 Second reflector element

[0206] 50 Rotating mechanism

[0207] 51 Camera

[0208] 52 Camera Lens

[0209] 53 First Light Source

[0210] 530 Second Light Source

[0211] 54 Sample Room

[0212] 55 First illumination beam path

[0213] 550 Second illumination beam path

[0214] 57 samples

[0215] 58 first reflector element

[0216] 580 Second reflector element

[0217] A. The first sub-field of view

[0218] B The second sub-field of view

[0219] C The third sub-field of view

[0220] 60 X-ray optics

[0221] 61 samples

[0222] 62 Sample stage

[0223] 63 X-ray source

[0224] 64 Camera

[0225] 65 Optical reflector element

[0226] 66 X-ray detector

[0227] 67 Sample Room

[0228] 68 X beam

[0229] 69 Lighting Unit

[0230] 71 Special optical devices for microscopes

[0231] 72 Eyepiece

[0232] 73 Microscope Camera (Imaging Camera)

[0233] 74 Bracket

[0234] 75 reflector element

[0235] 76 Camera

[0236] 77 samples

[0237] 78 Sample stage

[0238] 79 Sample Room

[0239] 80 Lighting Units

[0240] A. The first sub-field of view

[0241] B The second sub-field of view

[0242] 600 Microscope System (FIB-SEM Combined Equipment)

[0243] 610 Electron Beam Column

[0244] 620 Electron Source

[0245] 630 First condenser lens system

[0246] 640 Optical axis of electron beam column

[0247] 650 Second condenser lens system

[0248] 660 Aperture Stop

[0249] 670 Deflection System

[0250] 680 Objective Lens System (SEM)

[0251] 690 Sample Room

[0252] 700 Detector

[0253] 710 Evaluation and control unit

[0254] 720 Gas Injection System

[0255] 730 Sample Stage

[0256] 740 Sample Holder

[0257] 750 samples

[0258] 760 lens system

[0259] 770 Second Deflection System

[0260] 780 Optical axis of ion beam column

[0261] 790 Ion Source

[0262] 800 objective lens system (FIB)

[0263] 810 Ion Beam Column

[0264] 820 Aperture Stop

[0265] R Rotation axis of the sample stage

[0266] T Tilt axis of the sample stage

[0267] XX axis

[0268] YY Axis

[0269] ZZ axis

[0270] S1 Provide samples

[0271] S2 Place the sample in the first position

[0272] S3 takes the first view of the sample with the camera

[0273] S4 Place the sample at the second location

[0274] S5 Take a second view of the sample with the camera

Claims

1. A camera system for use in a microscope system, wherein the camera system is adapted to capture an optical image of an object, and the camera system comprises: - a camera having an image field; - and an optical mirror element, which has a mirror surface, wherein the mirror element can be arranged in the microscope system, It is characterized in that The image field of the camera includes at least a first sub-image field and a second sub-image field, The camera system is configured so that a first view of the object can be imaged into a first sub-image field of the camera via the reflective mirror surface. And a second view of the object can be imaged into the second sub-image field.

2. The camera system of claim 1 , wherein the camera has an optical axis and the mirror surface is oriented at an angle α to the optical axis of the camera, And the value of the angle α is 10° to 90°, so that the first view of the object and the second view of the object are different from each other.

3. The camera system according to claim 1, The reflective element is designed as one of the following embodiments: a plane mirror, a curved mirror, a prism, or a reflective surface of a component of the microscope system.

4. The camera system according to claim 1, Wherein the reflective element is combined with one of the following additional optical elements: Polarization filters, wavelength filters, special coatings. 5 . The camera system according to claim 1 , wherein the mirror element is designed to be movable.

6. The camera system according to claim 1, wherein the camera system comprises at least a first light source to illuminate the object, The mirror element is adapted to be part of both an imaging beam path and an illumination beam path for illuminating the object.

7. Camera system according to one of the preceding claims, wherein the camera system comprises a second reflective element having a second reflective mirror surface, And the image field of the camera includes a third sub-image field, And the camera system is configured to enable a third view of the object to be imaged through the second reflective mirror surface.

8. The camera system according to claim 1 , wherein the microscope system has a sample chamber for receiving a sample to be investigated, wherein vacuum conditions exist in the sample chamber during operation of the microscope system, And the mirror element is designed so that it can be arranged in the sample chamber.

9. The camera system according to claim 1, The reflective mirror surface has a conductive surface.

10. A method for recording an optical image of an object, the object being arranged in a microscope system, - wherein the microscope system comprises a camera and an optical mirror element; - and wherein the camera has an image field, the image field comprising at least a first image sub-field and a second image sub-field, - and the optical reflector element has a reflective mirror surface; And the method comprises the following steps: a) capturing a first view of the object, wherein a first imaging beam is guided from the object to the reflective mirror and from the reflective mirror to the camera, where the first imaging beam is imaged on a first sub-image field of the camera; b) capturing a second view of the object, wherein a second imaging beam is directed from the object to the camera where it is imaged onto a second sub-image field of the camera.

11. The method according to claim 10, wherein the object is a sample under a microscope, The microscope system has a displaceable sample stage for receiving the sample under the microscope. And the method comprises the following steps: - providing said sample on said sample stage; - moving the sample stage to arrange the sample at a first position relative to a camera and a mirror element, wherein the first view is taken at the first position of the sample; - moving the sample stage to arrange the sample at a second position relative to a camera and a mirror element, wherein the second view is taken at the second position of the sample. 12 . The method according to claim 10 , wherein the first image sub-field and the second image sub-field are evaluated independently of one another.

13. The method as claimed in claim 10, wherein two views are recorded simultaneously. 14 . A computer program product comprising a sequence of control instructions which causes a microscope system to execute the method according to claim 10 .

Images