Sample holder, loading device, and method for inserting sample into sample holder
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- LEICA MIKROSYSTEME GMBH
- Filing Date
- 2023-05-23
- Publication Date
- 2026-06-01
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a sample holder, a loading device, and a method for inserting a sample into the sample holder.
Background Art
[0002] Cutting and polishing with an ion beam is an established process for preparing samples (i.e., specimens) for electron microscopy This process has the advantage that no mechanical stress is applied to the sample The process is suitable for samples in many different application fields, for example, lithium ion batteries (LiBs) The LiB thin film is composed of hard materials, soft materials, and brittle materials In contrast to ion etching, the associated fine structures or fine pores cannot be exposed by mechanical cutting or polishing
[0003] In the case of ion beam processing, a mask (shielding plate) is aligned with the edge of the sample, and the mask shields the sample up to the height at which the sample is prepared Next, the mask and the sample are placed in a vacuum chamber The ion beam is directed at the mask, a part of the beam becomes the shadow of the mask, and the remaining part cuts the sample up to the edge of the mask by physical sputtering
[0004] During this process, heat is induced via the ion beam As a result, deformation or even damage (due to melting) of the sample may occur Therefore, in the case of heat-sensitive samples, additional cooling of the mask and the sample may be applied
[0005] Many sample types need to be stored under vacuum or in a protective atmosphere (such as LiB) to avoid reaction of the material with ambient air Therefore, for example, it may be necessary to attach the sample and the mask to the holder even under difficult conditions such as inside a glove box Finally, the sample holder for this application needs to provide the possibility of direct transfer into the electron microscope without the need to reposition the sample, which involves the risk of damaging the finally prepared sample
[0006] International Publication No. 2021 / 059401, DE112014002250T5, U.S. Patent Application Publication No. 2022 / 0051870, and U.S. Patent Application Publication No. 2022 / 0020558 relate to sample holders for use in ion mills. Inserting samples into the holder presents challenges, especially when used under difficult conditions (e.g., inside a glove box). Furthermore, positioning the holder's protrusions above the edge of the mask / shielding plate is inaccurate and, for example, extremely difficult to achieve inside a glove box. Moreover, sample cooling may not be adequately addressed by the sample holder.
[0007] There may be a demand for improved concepts for handling samples. [Overview of the Initiative] [Means for solving the problem]
[0008] This need is addressed by the subject matter of the independent claim.
[0009] Various examples in this disclosure are based on the finding that sample handling needs to be designed to be quick and easy, thereby reducing the time required for the user to carry out the sample insertion process and improving the quality and success rate of sample preparation. In the proposed concept, sample handling can be improved by providing a sample holder (i.e., specimen holder) that has a retaining mechanism (i.e., a mechanism configured to hold the sample in place within the sample holder) which can be opened by mechanical action and automatically returns to a closed state when the mechanical action is released. For example, the mechanical action can be provided by a loading device, which can also facilitate loading of the sample holder by providing guide rails for inserting the sample into the sample holder. Both the sample holder with the retaining mechanism and the loading device that can be used to provide mechanical action can facilitate and speed up the insertion of the sample into the sample holder, thus reducing the time required and potentially improving the quality and success rate of sample preparation.
[0010] Various aspects of this disclosure relate to a sample holder. The sample holder comprises a main component having a first surface area. The sample holder further comprises a retaining mechanism having a retaining component. The retaining mechanism is configured to hold a sample between the retaining component of the retaining mechanism and the first surface area when the retaining mechanism is closed. The retaining mechanism is configured to be open when the mechanical operation of the retaining mechanism is performed. The open state allows for the insertion and removal of a sample. The retaining mechanism is configured to return to a closed state when the mechanical operation is released. By opening in response to mechanical operation and returning to a closed state when the mechanical operation is released, the insertion of a sample into the sample holder is facilitated, thus reducing the time required and improving the quality and success rate of sample preparation.
[0011] As outlined above, the sample holder can be used in combination with a loading device, which is provided to operate a retaining mechanism. For example, the retaining mechanism can be configured to open when the mechanical components of the loading device are mechanically activated. This makes it easier to insert the sample into the sample holder because the operation of the retaining mechanism is assisted by the loading device.
[0012] The sample holder and loading device can be designed to be parallel to each other, and the mechanical components of the loading device will automatically align with the respective components of the sample holder's holding mechanism when the sample holder is attached to the loading device (e.g., fixed in place). The sample holder can have an interface for accommodating the mechanical components of the loading device when the sample holder is attached to the loading device. In other words, the sample holder can be designed so that its interface aligns with the mechanical components when the sample holder is attached to the loading device.
[0013] The automatic return of a clamping mechanism can be achieved using an elastic element such as a spring. For example, the clamping mechanism may be equipped with a spring that is compressed when the clamping mechanism is actuated. In its preloaded state, the spring presses the retaining component of the clamping mechanism toward a first surface area of the main component, thereby tightening the specimen between the retaining component and the first surface area. Thus, the spring can provide an automatic return to the closed state when the mechanical action is released.
[0014] In various examples, in addition to inserting the sample into a sample holder, the sample can be inserted between two support layers to support thin and / or brittle samples. The holding mechanism can be configured to hold the laminate containing the sample. A first surface area can be provided to form a first boundary area with the longitudinal surface area of the laminate. The main component may further include a second surface area provided to form a second boundary area with the transverse surface area of the laminate. The laminate can be pressed against the first surface area (when the holding mechanism is closed), thereby holding the laminate in the sample holder due to increased mechanical friction. The second surface area can be used to align the laminate within the sample holder. For example, the laminate can be slid into the sample holder until it is pressed against the second surface area, so that the laminate and the sample holder are aligned and the layers of the sample holder are aligned with each other.
[0015] In various examples, the main component may include a fixing device for securing the sample holder to the loading device (or sample stage). This can assist in the alignment of the mechanical components with the sample holder and the alignment of the sample holder with the (optional) guide rail for inserting the sample into the sample holder.
[0016] As outlined above, various examples of this disclosure relate to concepts for holding laminates during an ion milling process, for example, as preparations for electron microscopy. Accordingly, a sample holder may be suitable for holding a laminate containing a sample during an ion milling process. Generally, such samples are small. For example, the laminate may have a vertical height of at most 10 mm (or at most 5 mm or at most 2 mm). Accordingly, the vertical distance between the holding component of the holding mechanism and the first surface region may be at most 10 mm (or at most 5 mm or at most 2.5 mm) when the holding mechanism is open.
[0017] Generally, a sample holder can surround the main portion of a sample or a laminate containing a sample. Therefore, cooling may be applied through the sample holder to cool the sample. In the proposed concept, the sample or laminate is pressed against a first surface area. For example, at least the first surface area may contain a metal such as copper having a thermal conductivity of at least 250 W / m*K. This can assist in the cooling of the sample. Other components, such as the springs of the holding and / or pressing mechanism, may similarly contain such metals.
[0018] Various examples of this disclosure relate to loading devices for sample holders, for example, the loading devices for sample holders described above. The loading device comprises mechanical components for activating the retaining mechanism of the sample holder to release the retaining mechanism of the sample holder. The release state allows for the insertion of a sample into the sample holder and the removal of a sample from the sample holder. As outlined in relation to sample holders, the loading device can further facilitate the insertion of a sample into the sample holder because the operation of the retaining mechanism is assisted by the loading device.
[0019] In some configurations, the mechanical components may be movable. For example, the loading device may include a mechanism for moving the movable mechanical components. In this way, the sample holder retaining mechanism can be activated and deactivated while the sample holder is attached to the loading device.
[0020] For example, a lever and an eccentric element can be used to move a movable mechanical component, thereby activating a retaining mechanism. The mechanism may comprise a lever and an eccentric element. The lever may be configured to rotate the eccentric element, and the eccentric element may be configured to move the movable mechanical component. Such a lever can be easily used even inside a glove box.
[0021] The loading device may have further affordances for aligning the sample holder with the loading device and / or for inserting the sample into the sample holder. For example, the loading device may have a first recess for accommodating the sample holder. For example, the first recess may be used to align the sample holder with the loading device in a first lateral dimension. The loading device may further have a stop surface area, which is positioned so that when the sample holder is inserted into the first recess up to the stop surface area, the sample holder aligns with the mechanical components. This facilitates the alignment of the sample holder with the loading device in a second lateral dimension. For example, this alignment in two dimensions may allow the sample holder (particularly the interface of the retaining mechanism) to align with the mechanical components of the loading device.
[0022] Another affordance relates to the process of sliding the sample into the sample holder. For example, the loading device may have a second recess to guide the insertion of the sample, such as a laminate containing the sample, into the sample holder. This can further facilitate the insertion process.
[0023] Therefore, the combination of the first recess, the stop surface region, and the second recess can facilitate the sample insertion process. For example, a sample holder can be inserted into the first recess and slid toward the stop surface region until it is pressed against the stop surface region. In this position, the sample holder can be aligned with mechanical components. For example, the sample holder can be fixed to the loading device so that it remains in this position. After the retaining mechanism is activated, the second recess can be used to guide the insertion of the sample into the sample holder. This can be achieved mechanically by arranging the two recesses at different heights. For example, the loading device may comprise a first part having a first vertical height and a second part having a second vertical height. The first part may comprise the first recess, and the second part may comprise the second recess. The second vertical height may be greater than the first vertical height. For example, a sample holder can be slid toward a second part of the loading device while being guided by a first recess. When the sample holder is pressed toward the second part, the sample can be slid toward the sample holder by being guided by the second recess, which may be at a vertical height that aligns with the first surface area when the sample holder is inserted into the first recess. Substantially, the stopping surface area mentioned above may be provided by the surface area of the second part facing the first part. In other words, the surface area of the second part facing the first part may comprise a stopping surface area for aligning the sample holder with the mechanical components.
[0024] In some examples, the loading device further includes threads for accommodating screws or bolts for securing the sample holder to the loading device. Once the sample holder is secured to the loading device, alignment with the mechanical components and alignment with the second recess can be maintained.
[0025] Some aspects of the present disclosure relate to a method for inserting a sample into a sample holder for holding the sample during an ion milling process. The method includes placing the sample between a first support layer and a second support layer to form a laminate including the sample. The method includes inserting the laminate into the sample holder. By using the laminate, a fragile and / or thin sample can be stably held during the ion milling process and the insertion process.
[0026] Generally, the first support layer and the second support layer can not only provide additional stability during the ion milling process and the insertion process, but also facilitate the removal of surplus materials. For example, the method can include cutting the surplus materials of the sample at the edges of the first support layer and the second support layer after placing the sample between the first support layer and the second support layer. Therefore, the sample does not need to be accurately shaped before insertion, thereby further facilitating the preparation of the sample. For example, the surplus materials of the sample can be cut after inserting the laminate into the sample holder.For example, the alignment between the layers can be forced by the sample holder, for example, by the surface area, and / or by the pressing mechanism of the sample holder, facilitating the accurate cutting of the surplus materials.
[0027] For example, as outlined in relation to the sample holder introduced above, the sample holder can include a main component with a first surface area for accommodating the longitudinal surface area of the laminate, and a pressing mechanism. The act of inserting the laminate into the sample holder can include sliding the laminate into an opening between the first surface area of the main component and the holding component of the pressing mechanism. For example, when the laminate is inserted into the sample holder, the pressing mechanism can be in a closed state, and the pressing mechanism can clamp the laminate towards the first surface area, thus holding the laminate in the sample holder.
[0028] In some examples, the main component of the sample holder can further include a second surface area for accommodating a lateral surface area of the laminate. The act of inserting the laminate into the sample holder can include sliding the laminate into an opening between the first surface area and the holding component until the laminate is pressed against the second surface area of the main component. For example, the second surface area can be used to align the laminate with the sample holder and to align the layers of the laminate with each other.
[0029] As outlined in relation to the sample holder, the clamping mechanism can have two states: an open state in which the laminate can be inserted, and a closed state in which the laminate is clamped by the clamping mechanism. To switch between the two states, the clamping mechanism can be actuated mechanically. Thus, the method can include actuating the clamping mechanism of the sample holder to place the clamping mechanism in the open state to provide an opening between the first surface area and the holding component. The laminate can be inserted into the sample holder while the clamping mechanism is in the open state. In other words, the clamping mechanism can be (temporarily) actuated to enable easy insertion of the laminate into the sample holder.
[0030] To facilitate this actuation, a loading device such as the aforementioned loading device can be used. For example, the method can include attaching the sample holder to the loading device. The method can include moving a movable mechanical component of the loading device to actuate the clamping mechanism of the sample holder to place the clamping mechanism in the open state. For example, the act of moving the mechanical component can include rotating an eccentric element that moves a movable mechanical component of the loading device and thus rotating a lever of the loading device to actuate the clamping mechanism of the sample holder. This can facilitate opening (closing) the clamping mechanism and thus facilitate the sample insertion process.
[0031] Once the laminate is inserted into the sample holder, the sample holder can be removed from the loading device and inserted into the sample stage (for alignment and / or used in the ion milling process). For example, the method may include inserting the sample holder with the laminate into the sample stage and aligning the laminate with a mask for use in the ion milling process. For example, aligning the laminate with the mask may include aligning the laminate with the mask in the first and second dimensions, and then rotating the sample stage to align the laminate with the mask in the third dimension. By rotating the sample stage with the sample holder, it is possible to align the mask in the third dimension with the same microscope used for alignment in the first and second dimensions.
[0032] In some examples, one of the support layers may have an inclined edge, which can facilitate the alignment process. For example, one of the first and second support layers may have an inclined edge for aligning the laminate with the mask during the ion milling process. For example, to make the process more economical, the reuse of each support layer can be made possible by providing a laterally square support layer with two or more inclined edges, for example, four inclined edges. In this case, the support layer can be used four times before a new support layer is needed.
[0033] As outlined in relation to the sample holder, a major consideration during the ion milling process is the cooling of the sample. Methods may include ion milling the sample. Cooling can be applied to the sample during the ion milling process via the first and second support layers and the surface area of the sample holder. For example, the support layers may be metallic, which improves heat conduction and thus provides heat dissipation and cooling. This can protect samples sensitive to thermal damage.
[0034] Some examples of apparatus and / or methods are described below, for illustrative purposes only, with reference to the attached diagrams. [Brief explanation of the drawing]
[0035] [Figure 1a] This is a schematic diagram showing an example of a sample holder. [Figure 1b] This is a schematic diagram showing an example of a sample holder. [Figure 1c] This is a schematic diagram showing an example of a laminate containing a sample. [Figure 1d] This is a schematic diagram showing an example of a sample holder fixed to a loading device. [Figure 2a] This is a schematic diagram showing an example of a loading device for a sample holder. [Figure 2b] This is a schematic diagram showing an example of a loading device equipped with a sample holder, before the sample is inserted into the sample holder and with the sample holder's retaining mechanism in the closed position. [Figure 2c] This is a schematic diagram showing an example of a loading device equipped with a sample holder, before the sample is inserted into the sample holder and with the sample holder's retaining mechanism in the closed position. [Figure 2d] This is a cross-sectional view showing an example of a mechanism for moving the mechanical components of a loading device. [Figure 2e] This is a schematic diagram showing an example of a loading device equipped with a sample holder, where the sample holder's retaining mechanism is in the open position. [Figure 2f] This is a schematic diagram showing an example of a loading device equipped with a sample holder, where the sample holder's retaining mechanism is in the open position. [Figure 2g] This is a schematic diagram showing an example of a loading device equipped with a sample holder, where the sample holder's retaining mechanism is in the open position. [Figure 2h] This is a schematic diagram showing the insertion of the laminate into the sample stage via the recess of the loading device. [Figure 2i] This is a cross-sectional view showing an example of a mechanism for moving the mechanical components of a loading device after a sample has been inserted into a sample holder attached to the loading device. [Figure 3]This is a flowchart illustrating an example of a method for inserting a sample into a sample holder. [Figure 4a] This is a schematic diagram illustrating the process for aligning the mask with the sample in preparation for the ion milling process. [Figure 4b] This is a schematic diagram illustrating the process for aligning the mask with the sample in preparation for the ion milling process. [Figure 4c] This is a schematic diagram illustrating the process for aligning the mask with the sample in preparation for the ion milling process. [Figure 4d] This is a schematic diagram showing an example of alignment between a laminate containing a sample and a mask. [Figure 4e] This is a schematic diagram illustrating an example of an ion milling process. [Modes for carrying out the invention]
[0036] Here, various examples are illustrated in more detail with reference to the attached diagrams. In the diagrams, line thickness, layer thickness and / or area thickness may be exaggerated for clarity.
[0037] The sample holder, loading device, and method for inserting the sample into the sample holder are described in more detail below with reference to the attached diagrams. Furthermore, the proposed sample holder, loading device, and method are shown to be applied to the preparation of samples for observation with a scanning electron microscope.
[0038] To accurately image the structure of a sample with a scanning electron microscope, the prepared sample must be free from artifacts induced during preparation. A proven common method is to cut and polish the sample with a broad ion beam. When using such ion beam cutting and polishing, no mechanical stress is applied to the sample. However, the ion beam can heat the sample. To avoid thermal damage, the holder can be cooled during processing.
[0039] Such a preparation process is particularly suitable for the preparation of highly sensitive battery thins. Care can be taken to ensure that such samples remain mechanically and chemically intact to avoid damage. The proposed sample holder, loading device, and method can provide an improved concept for preparing samples for such ion milling processes.
[0040] Figures 1a and 1b show schematic diagrams of an example of a sample holder 100. Figure 1a shows a side view of the sample holder 100, while Figure 1b shows an isometric view. The sample holder 100 comprises a main component 110 having a first surface area 112. The sample holder comprises a pressing mechanism 120 having a retaining component 122. In the closed state of the pressing mechanism 120, the pressing mechanism 120 is configured to press the sample 14 between the retaining component 122 of the pressing mechanism and the first surface area 112. The pressing mechanism is configured to open when the mechanical operation of the pressing mechanism is performed. The open state allows for the insertion and removal of the sample. The pressing mechanism is configured to return to the closed state when the mechanical operation is released.
[0041] The proposed sample holder comprises two components: a main component 110 (also referred to as the “retaining block”) which may be a metal block, and a pressing mechanism 120 which has one or more (metal) components that are movable (or compressible) relative to the main component. For example, the main component may be a machined or molded (single) metal block, and the main component may accommodate other components or other components of the sample holder. The pressing mechanism 120 may be separate from the main component 110 but attached to the main component 110, or it may be completely separate from the main component. For example, as shown in Figure 1a, the pressing mechanism 120 may comprise a retaining component 122 and a spring 124. The spring 124 may be attached to the main component 110 and / or to the bottom component 128 of the clamp comprising the retaining component 122, for example, by welding, adhesive, shape fitting or pressure fitting. Alternatively, the spring 124 may not be attached to the main component 110 and / or the bottom component 128. For example, the spring 124 may simply be packed between the main component 110 and the bottom component 128 of the clamp.
[0042] In the examples shown in Figures 1a, 1b, and 1d, the retaining component 122 is part of a bent metal piece (also referred to as a "clamp") comprising the retaining component 122, a lateral component 126, and a bottom component 128. The clamp comprises or is constructed from a thin, highly thermally conductive, bent metal sheet, and the clamp can enclose the main component. The clamp may have an opening on the front side, i.e., between the two parts of the retaining component. The clamp can be used to uniformly press a specimen, or a laminate containing a specimen, against the main component on both sides via a spring. For example, when the pressing mechanism is actuated, the spring 124 may be compressed. The spring 124 is positioned vertically between the bottom component 128 and the main component 110 of the bent metal piece. In the context of this disclosure, the vertical dimension can be defined perpendicular to the first surface region 112. Correspondingly, the lateral dimension can be defined parallel to the first surface region 112. As shown in Figure 1a, the preloaded (e.g., normal) spring 124 presses the retaining component 122 of the holding mechanism toward the first surface region 112 of the main component, thereby tightening the sample 14 (which is a portion of the laminate 10 in Figures 1a, 1b, and 1d) between the retaining component 122 and the first surface region 112. The lateral component 126 of the bent metal piece and the second surface region 114 of the main component 110 can further restrain the lateral movement of the sample 14.
[0043] The holding mechanism 120 has two states: an open state that allows the sample to be inserted into the sample holder, and a closed state in which the sample is held down within the sample holder, particularly between the retaining component 122 and the first surface region 112. For example, the holding mechanism 120 can be configured to hold down the sample or a laminate containing the sample in the closed state, and to release the sample or laminate in the open state. In this context, "holding down" means, for example, that the sample or a laminate containing the sample is held down between the retaining component and the first surface region, strongly held, and / or tightened, so that in the closed state of the holding mechanism 120, the sample or laminate cannot be moved or removed without applying excessive force. Correspondingly, "releasing" means loosening the sample or laminate so that, as a result, the sample or laminate can be moved with little force in the open state of the holding mechanism.
[0044] In the proposed concept, the sample holder is suitable for small and / or thin samples. Figure 1c shows a schematic diagram of an example of a laminate containing a sample. For example, as shown in Figure 1c, the sample may be a thin film sample 14, which can be placed between a first support layer (i.e., plate) 12 and a second support layer (i.e., plate) 16 to form a laminate containing the sample 14. In other words, the sample can be placed (e.g., inserted, clamped) between the two support layers, thus forming a "sample sandwich". Therefore, the sample holder may be suitable for holding a laminate containing a sample during the ion milling process. A holding mechanism may be configured to hold the laminate 10 containing the sample 14. Therefore, the sample holder may be a device for holding fragile, thermosensitive samples for use in particle beam systems. With the use of a laminate and the assistance of a holding mechanism, it is not necessary to fix or embed the sample with adhesive.
[0045] In various examples, sample 14 may be a sample thin, such as a thin section of a lithium-ion battery. Therefore, the vertical opening provided by the open-state retaining mechanism may be small, for example, having a vertical height of at most 10 mm. For example, the vertical distance between the retaining component of the retaining mechanism and the first surface region may be at most 10 mm (or at most 5 mm or at most 2.5 mm) when the retaining mechanism is open. Therefore, the sample holder may be suitable for samples or laminates having a vertical height of less than 10 mm (or less than 5 mm or less than 2.5 mm). In the example of the lithium-ion battery thin section described above, the resulting laminate has a vertical height of about 2 mm.
[0046] To avoid damaging the sensitive holder material, care can be taken to ensure that the force is applied uniformly when tightening the holder. In other words, the force can be applied uniformly to the sample. This can be ensured by positioning the sample between two support layers that can help distribute the force across the entire sample, and / or by using a retaining component 122 with a large surface area. For example, the retaining component 122 can cover at least 25% (or at least 30%, or at least 40%, or at least 50%) of the surface area portion (facing the retaining component 122) of the support layer that is positioned between the sample and the retaining component 122 when the laminate is inserted into the sample holder.
[0047] As shown in Figures 1a to 1d, one of the support layers (for example, the support layer designated to face the ion beam) may have an inclined edge, i.e., the support layer may be beveled at an angle. In other words, one of the first and second support layers may have an inclined edge for aligning the laminate with the mask during the ion milling process. This inclined edge or bevel facilitates alignment with the mask during preparation. The support layer (facing the ion beam and thus away from the first surface region) may be symmetrical, for example, having a square lateral shape with the same inclined edge on all four sides. Thus, the other layers of the laminate may also have a square lateral shape. The support layers wear down during the preparation process. Due to symmetry, the support layer can be used four times (on the four beveled edges) and then needs to be replaced.
[0048] In various examples, care is taken to assist in the cooling of the sample during the ion milling process. For this reason, the main component 110, the holding mechanism 120 and / or the support layer may be made of a metal, for example, a metal with high thermal conductivity, or may include one. For example, at least the first surface region (e.g., at least one of the first surface region, the entire main component, the holding component, the spring, the lateral component and the bottom component) may contain a metal having a thermal conductivity of at least 250 W / m*K, such as copper, silver, or gold. Both the sample holder and the beam shielding mask can be actively cooled so that the heat-sensitive sample is sufficiently cooled.
[0049] The sample, or a laminate containing the sample, is placed on a first surface area 112 of the main component. As a result, the first surface area can be provided to form a first boundary area with the longitudinal surface area 10a (shown in Figure 1c) of the sample or laminate, the longitudinal surface area 10a facing the first surface area 112. In some examples, the first surface area 112 on which the sample or laminate is placed may be smooth. In this case, the sample or laminate may be constrained by the (multiple) lateral components of the pressing mechanism in both directions of the first transverse dimension, and may remain unconstrained in the second transverse dimension (perpendicular to the first transverse dimension). Alternatively, a stopper may be included adjacent to the first surface area, and the sample or laminate (i.e., sample sandwich) may be pressed against this stopper. In other words, the main component may further comprise a second surface region 114 provided to form a second boundary region with the lateral surface region 10b (shown in Figure 1c) of the sample or laminate, the lateral surface region 10b facing the second surface region 114. The second surface region 114 can be provided by a portion of the main component 110, such as a rim of the main component 110, and the second surface region 114 is provided to restrain the movement of the sample or laminate in one direction of the second lateral dimension, thereby providing a stopping point for the sample or laminate when it slides between the holding component 122 and the first surface region 112.
[0050] To simplify the secure loading of the sample, the proposed concept uses the (spring-based) retaining mechanism described above. To further facilitate the process, the retaining mechanism can be used in combination with a special loading aid referred to as a "loading device," which is particularly easy to handle (even under difficult conditions). Such a loading device 200 is shown in Figures 1d and 2a-2i. Figure 1d shows a schematic diagram of an example of a sample holder 100 fixed to the loading device 200 and a schematic diagram of an example of a system comprising the loading device 200 and the sample holder 100. One possible task of such a loading device 200 is to actuate the retaining mechanism 120. As outlined above, the retaining mechanism is configured to be open when the mechanical actuation of the retaining mechanism occurs and to return to a closed state when the mechanical actuation is released. This mechanical actuation can be provided by the loading device. For example, the retaining mechanism can be configured to be open when the mechanical actuation of the retaining mechanism occurs by the mechanical components 210 of the loading device 200. In other words, the loading device may include a mechanical component 210, which may be a piston, that can be configured to actuate a retaining mechanism 120 when the sample holder 100 is attached to the loading device 200. For example, the retaining mechanism 120 can be actuated by the mechanical component 210 pressing against a bottom component 128 of the retaining mechanism 120, and thus compressing a spring 124. The sample holder may include an interface 130, such as a recess or opening, for accommodating the mechanical components of the loading device when the sample holder is attached to the loading device. More details regarding the actuation of the mechanical component 210 and, by extension, the retaining mechanism 120, are shown in relation to Figures 2a to 2i. However, the actuation of the retaining mechanism 120 is not generally limited to being carried out by the loading device. In more general terms, the retaining mechanism 120 can be designed to be actuated with or without the loading device by including, for example, a surface area such as a bottom component 128 suitable for manual compression of the spring 124 of the retaining mechanism 120.
[0051] To assist the loading / attaching process, the sample holder 100 can be fixed (i.e., mounted) to the loading device. Therefore, the main component may further comprise a fixing device 140, such as a recess or hole, for fixing the sample holder to the loading device 200 or sample stage using, for example, screws or bolts 255 (e.g., shown in Figures 2c and 2d). The main component 110 shown in Figure 1b has an opening 140 (e.g., a recess) to which the sample holder can be fixed to an instrument (e.g., a sample stage) or onto the loading device 200 (shown in Figure 1d). For example, as shown in Figures 1b and 1d, the main component 110 may comprise a U-shaped recess (with an angled edge) for accommodating screws or bolts.
[0052] By simplifying the handling and design of sample holders, it is possible to help maintain the integrity of thin, unstable, and fragile samples throughout the preparation process, from insertion into the sample holder to insertion into the electron microscope. This saves time, prevents sample loss, and supports reproducible high-quality sample preparation.
[0053] More details and embodiments of the sample holder, loading device, and sample are referred to in relation to the proposed concept or one or more examples described above or below (e.g., Figures 2a to 4e). The sample holder, loading device, and sample may have one or more additional optional features corresponding to one or more embodiments of the proposed concept or one or more examples described above or below.
[0054] Figure 2a shows a schematic diagram of an example of a loading device 200 (i.e., a loading device) for a sample holder 100, for example, for the sample holder 100 shown in relation to Figures 1a to 1d. The loading device 200 includes a mechanical component 210 for activating the sample holder's retaining mechanism to release the retaining mechanism, which allows for the insertion of a sample into the sample holder and the removal of a sample from the sample holder.
[0055] In relation to Figures 1a to 1d, the use of a loading device 200 in combination with a sample holder 100 is shown. To insert a sample into the sample holder, the sample holder can be placed on the loading device. Using a mechanism (which may include mechanical components 210) within the loading station, the spring 124 of the retaining mechanism 120 of the sample holder 100 can be compressed, thereby moving the clamp with the retaining component 122 away from the holding block (i.e., the main component). This creates a free space into which a sample or laminate (i.e., a sample sandwich) can be inserted. Here, the sample or laminate may simply be pressed between the retaining component 122 and the first surface area 112. After the mechanism is released, the spring relaxes, and the sample or laminate is secured to the holding block (i.e., the main component) via the clamp (e.g., by the retaining component 122 of the clamp). Here, any protruding sample material can be cut on the rear support plate to obtain a smooth edge for subsequent preparation.
[0056] A mechanical component 210 is used to operate the retaining mechanism. In particular, a movable mechanical component 210 may be used, as shown in relation to Figures 2a to 2i, that is, the mechanical component 210 can move relative to the sample holder and / or other components of the loading device 200. In other words, the mechanical component may be a movable mechanical component. For example, as will be apparent in relation to Figures 2d and 2f, the mechanical component 210 may be a piston configured to move toward the sample holder and away from the sample holder (when the sample holder is attached to the loading device), and to alternately operate the retaining mechanism (i.e., open the retaining mechanism by compressing the spring 124, for example) and not operate the retaining mechanism (i.e., close the retaining mechanism by ceasing to apply force to the spring 124, resulting in the spring returning to a preloaded state). To provide movement for the mechanical components 210, the loading device 200 may include a mechanism 220 for moving the movable mechanical components.
[0057] In the example shown in Figures 2a to 2i, the movable mechanical component is rotated by an eccentric element 224 (shown in Figures 2d, 2f, and 2i), and the eccentric element is rotated by a lever 222. In other words, the mechanism for moving the movable mechanical component 210 can include a lever 222 and an eccentric element 224, the lever being configured to rotate the eccentric element, and the eccentric element being configured to move the movable mechanical component.
[0058] Next, the procedure for inserting the sample (or the laminate containing the sample) will be explained with reference to Figures 2a to 2i.
[0059] Figure 2a shows the loading device 200 without the sample holder 100, for example, before or after the sample holder 100 is attached to the loading device 200. Figure 2a shows the loading device 200 comprising a movable mechanical component 210 (in the retracted position), a lever 222, a first recess (or first groove) 230, a stop surface area 235, a second recess 240, and threads 250 for a screw or bolt. The purpose of the first recess 230, the stop surface area 235, the second recess 240, and the threads 250 will become clear below.
[0060] Figures 2b and 2c show schematic diagrams of an example of a loading device equipped with a sample holder 100. In Figure 2b, the sample holder 100 is positioned within a first recess 230 configured to accommodate the sample holder 100. In particular, the first recess 230 can be used to guide the sample holder 100 toward alignment with a mechanical component 210. For example, the sample holder may be inserted into the first recess and slid toward the stop surface region 235 (as shown in Figure 2a) until the sample holder is pressed toward the stop surface region 235, where it is aligned (laterally) with the mechanical component. The stop surface region 235 is positioned so that the sample holder aligns with the mechanical element once the sample holder is inserted into the first recess up to the stop surface region. In Figure 2b, the sample holder is shown in the aligned position with the mechanical element before a sample is inserted into the sample holder and when the sample holder's retaining mechanism is closed.
[0061] In this position, the sample holder can be fixed (e.g., mounted) to the loading device, and the alignment is maintained. For this purpose, a thread 250 can be used. The thread 250 may be suitable for housing a screw or bolt 255 for fixing the sample holder to the loading device. The screw or bolt 255 (shown in Figure 2c) can be inserted into the thread 250 through the recess 140 of the sample holder 100, so that the sample holder is fixed (i.e., mounted, fastened) to the loading device.
[0062] Figure 2d shows a cross-sectional view of an example of a mechanism for moving the mechanical component 210 of the loading device. At this point, the mechanical component (e.g., piston 210) and the eccentric element 224 are also in the “down” (i.e., retracted) position where the retaining mechanism is not acting. Guide markers are provided to the user to help the user distinguish between the positions. The mechanical component 210 for raising and lowering the spring 124 can be actuated via the eccentric element 224, which is rotated by the lever 222.
[0063] When the sample holder is attached to the loading device, the lever may be rotated to the opposite side (see Figure 2e), as a result of rotating the eccentric element 224, which presses the mechanical component 210 toward the bottom component of the retaining mechanism of the sample holder 100 (through the interface 130), ultimately compressing the spring 124 (thus activating the retaining mechanism and releasing it), providing an opening between the holding component 122 and the first surface area 112 (see Figure 2f). In effect, the holding component is lifted, providing access for loading a sample or laminate into the sample holder. Figures 2e to 2g show schematic diagrams of an example of a loading device with a sample holder, where the retaining mechanism of the sample holder is in the open position.
[0064] After the retaining mechanism is activated and subsequently released, the second recess 240 can be used to guide the insertion of the sample into the sample holder. In particular, the second recess 240 can be used to guide the insertion of a sample, such as a laminate containing the sample, into the sample holder. This can be mechanically achieved by arranging the two recesses at different heights. For example, as shown in Figures 2a to 2i, the loading device may comprise a first part having a first lower vertical height and a second part having a second higher vertical height. The first part may comprise a first recess 230, and the second part may comprise a second recess 240. In practice, the first recess 230 is lower in height compared to the second recess 240. The first recess 230 can be used to guide the sample holder 100 (its sliding motion) toward the second portion having the second recess 240 until the sample holder 100 contacts a stop surface region 235 located on the surface region of the second portion facing the first portion. When the sample holder is pressed against the stop surface region 235, the sample holder may be aligned with both the mechanical component 210 and the second recess 240. For example, the second recess may be at a vertical height that aligns with the first surface region 112 of the main component of the sample holder when the sample holder 100 is inserted into the first recess 230. As shown in Figure 2g, at this position, the sample, or laminate 10, can be guided by the second recess 240 and slid into the sample holder 100.
[0065] Figure 2h shows a schematic diagram of inserting the laminate of layers 12;14,16 into the sample stage through the second recess 240 of the loading device. As can be seen in Figure 2h, the laminate may comprise a support layer 16, a sample 14, and a thin section mask support layer 12. As shown in Figure 2h, the thin section mask support layer 12 may have two openings, which may be suitable for picking up the thin section mask support layer 12 with tweezers.
[0066] After the sample or laminate is inserted, the lever can be returned to its initial position, which may cause the mechanical component 210 and the eccentric element 224 to return to the "down" position, and the sample holder returns to the closed position. Figure 2i shows a cross-sectional view of an example of a mechanism for moving the mechanical components of the loading device after the insertion of a sample into the sample holder attached to the loading device. As seen in Figure 2i, due to the height of the laminate, the spring 124 remains compressed and therefore exerts force on the laminate, which is pressed down and held correctly by the sample holder. In effect, the spring of the pressing mechanism secures the sample within the holder. Here, the sample is tightened within the sample holder. The sample holder can then be loosened (e.g., by loosening a screw or bolt) and (if necessary) any excess sample protrusions can be cut off. The sample holder is then ready to be transferred to the sample stage (e.g., for alignment with a mask used in an ion milling process).
[0067] More details and embodiments of the loading device, sample holder, and sample or laminate are referred to in relation to the proposed concept or one or more examples described above or below (e.g., Figures 1a-1d, 3-4e). The loading device, sample holder, and sample or laminate may have one or more additional optional features corresponding to one or more embodiments of the proposed concept or one or more examples described above or below.
[0068] Figure 3 shows a flowchart illustrating an example of a method for inserting a sample, such as those described in Figures 1a to 2i, into a sample holder, such as those described in Figures 1a to 1d, where the sample holder is suitable for holding and particularly holding the sample during the ion milling process. As will become clear, many features of the method have been described in relation to Figures 1a to 2i. Further details of other features will be described below.
[0069] The method begins with positioning the sample 14 between the first support layer 12 and the second support layer 16 to form a laminate 10 containing the sample 14 (as shown, for example, in Figure 1c). As outlined in relation to the previous figure, the sample 14 can be positioned between the support layers with appropriate alignment and pre-cutting of the sample 14. Due to the nature of the insertion process, the final alignment of the layers can be performed by the sample holder, because the layers are pressed against the second surface region and constrained by the (multiple) lateral components of the clamp of the holding mechanism.
[0070] After the sample is placed between the support layers, thereby forming a laminate, the laminate is inserted into the sample holder. As is evident in relation to Figures 1a to 2i, this insertion process can be further assisted by the sample holder's holding mechanism and optionally by a loading device.
[0071] The following assumes that a loading device will be used to assist the user when inserting the laminate into the sample holder. However, the use of the loading device is optional. For example, the user may manually operate the holding mechanism to insert the laminate into the sample holder.
[0072] When a loading device is used to assist the user, the method may include attaching the sample holder to the loading device 320. For example, attaching the sample holder 320 may include inserting the sample holder into a first recess of the loading device and sliding the sample holder along the first recess until the sample holder contacts the stopping surface area of the loading device, such that, for example, the interface and retaining mechanism are aligned with the mechanical components of the loading device and the fixing device of the sample holder (e.g., recess or opening) is aligned with the threads of the loading device. The sample holder can then be fixed to the loading device, for example, by fastening screws or bolts to the loading device via the threads.
[0073] The method may include activating the clamping mechanism of the sample holder 330 such that the clamping mechanism is in an open state, providing an opening between the first surface area and the retaining component. The laminate can then be inserted into the sample holder while the clamping mechanism is in an open state. As outlined in relation to the loading device, the clamping mechanism can be activated by moving the movable mechanical components of the loading device 330. The movable mechanical components can be actuated, in turn, by a lever and an eccentric element. Thus, the act of moving the mechanical components 336 may include rotating the lever of the loading device 332, and thus activating the clamping mechanism of the sample holder 330, in order to rotate the eccentric element 334 that moves the movable mechanical components of the loading device 336.
[0074] When the retaining mechanism is released, the laminate can be slid into the opening between the holding component of the sample holder and the first surface region of the main component. As outlined in relation to Figures 1a to 1d, the sample holder comprises a main component having a first surface region for accommodating the longitudinal surface region of the laminate and the retaining mechanism, and optionally a second surface region for accommodating the lateral surface region of the laminate. The act of inserting the laminate into the sample holder may include, for example, sliding the laminate into the opening between the first surface region of the main component and the holding component of the retaining mechanism until the laminate is pressed against the second surface region of the main component.
[0075] When the laminate is inserted into the sample holder, the retaining mechanism of the sample holder may be closed (for example, via a lever on the loading device), so that the retaining mechanism holds the laminate in place and the sample holder can be removed from the loading device. Furthermore, excess sample material (extending beyond the support layers) can be removed after the sample is positioned between the support layers (and held firmly by the retaining mechanism). Thus, the method may include cutting the excess sample material at the edges of the first and second support layers after the sample has been positioned between the first and second support layers.350 In general, excess sample material may be cut after the laminate is inserted into the sample holder, for example, when the laminate is held in place by the retaining mechanism. For example, the excess material may be cut after (or before) the sample holder is removed from the loading device.
[0076] Subsequently, the sample holder is inserted into the sample stage together with the laminate, where the sample holder can be aligned with the mask used in the ion milling process. Thus, the method may include inserting the sample holder with the laminate into the sample stage (of the preparation instrument, i.e., the ion mill) 360 and aligning the laminate with the mask for use in the ion milling process 370. For example, in the instrument (used to align the sample with the mask), the projection of the sample (including the laminate) onto the edge of the mask can be prepared by known methods used in optical microscopes and / or cameras. For example, firstly, the sample stage with the sample can be rotated 90° (downward) to align the sample horizontally and vertically with respect to the mask. Thus, aligning the laminate with the mask may include aligning the laminate with the mask in a first dimension and a second dimension (e.g., a horizontal dimension and a vertical dimension) 372. Next, to adjust the distance between the sample and the mask, the sample stage equipped with the sample holder may be rotated (returned) so that the sample stage is again in an upright position. In other words, the method may include aligning the laminate in the first and second dimensions, then rotating the sample stage 374, and aligning the laminate with the mask in the third dimension 376. Using the adjustment mechanism of the sample stage and the optical microscope / camera of the preparation apparatus, the sample can be positioned behind the edge of the mask so that the sample protrudes 20 μm to 100 μm parallel to the edge of the mask. The edge of the mask may be in loose contact with the sample across its entire width.
[0077] Figures 4a to 4e illustrate the alignment process. Figures 4a to 4c show schematic diagrams of the process for aligning the mask 410 with the sample 14 for the preparation of the ion milling process. In Figure 4a, the apparatus used for alignment is shown together with the sample stage 400, sample holder 420, and mask 410. As indicated by arrows 430 and 435, the sample can be moved vertically (430) and laterally (435). Alignment is performed using a microscope. Figure 4b shows a magnified view of the sample 14 and the edge of the mask 410. Figure 4c shows the spatial arrangement of the sample holder 420, sample 14, and mask 410. Figure 4c further shows the set screw 440 for setting the distance between the edge of the mask 410 and the sample 14.
[0078] Figure 4d shows a schematic diagram of an example of alignment between a laminate of layers 12;14;16 containing sample 14 and a mask 410. As shown in Figure 4d, one of the first and second support layers (in this case, the first support layer 12) has an inclined edge for aligning the laminate with the mask 410 during the ion milling process. The inclined / chamfered edge also facilitates the alignment process.
[0079] At this point, a preparation process (e.g., ion milling) may be initiated. Figure 4e shows a schematic diagram of an example of an ion milling process. The method (of Figure 3) may further include ion milling the sample 380. The mask 410 shields a portion of the (argon) ion beam emitted from the ion gun 450. The remaining portion of the beam strikes a sample sandwich 10 comprising or composed of a front support plate 12, the sample 14, and a rear support plate 16, removing the material to the height of the mask's edge by a sputtering process. By clamping the sample between the two support layers, bending can be prevented even with thin, soft, or brittle samples.
[0080] In general, irradiation with an ion beam can cause significant heat generation at the point of impact of the ion beam. The design of the sample holder may take into account that a heat-sensitive sample may be cooled during the preparation process in order to avoid damage to the heat-sensitive sample. Therefore, both support plates of a thin-section sample holder can have good thermal contact with the sample holder, and as a result, the support plates can be actively cooled via the stage and thus effectively cooled. In addition, the mask adjacent to the sample can be cooled, and if necessary, all the thermal energy introduced by the beam can be effectively dissipated. In fact, cooling may be applied to the sample during ion milling via the first and second support layers and the surface areas (e.g., the first and second surface areas) of the sample holder (and the entire sample holder, which includes a clamp with holding components, (multiple) lateral components, bottom components, and springs). To assist in cooling, the sample holder may contain or be made of metal, as described in relation to Figures 1a to 1d.
[0081] More details and embodiments of the method will be referenced in relation to the proposed concept or one or more examples described above or below (e.g., Figures 1a to 2i). The method may have one or more additional optional features corresponding to one or more embodiments of the proposed concept or one or more examples described above or below.
[0082] As used herein, the term "and / or" includes all possible combinations of one or more of the items listed herein and may be abbreviated as " / ".
[0083] While several embodiments have been described in the context of the apparatus, it is clear that these embodiments also represent descriptions of the corresponding methods, where blocks or apparatus correspond to steps or features of steps. Similarly, embodiments described in the context of steps also represent descriptions of the corresponding blocks, items, or features of the corresponding apparatus. [Explanation of symbols]
[0084] 10 Laminate 10a Longitudinal surface region 10b Transverse surface region 12. First support base 14 samples 16. Second support base 100 sample holders 110 Main components 112 First surface region 114 Second surface region 120 Retaining Mechanism 122 Retention Component 124 springs 126 Lateral components 128 Bottom component 130 Interfaces 140 Fixing devices, recesses, openings 200 Loading device 210 Mechanical components, pistons 220 Mechanism 222 Lever 224 Eccentric element 230 First recess 235 Stop surface area 240 Second recess 250 threads 255 Screws or bolts 310. Place the sample between the first support layer and the second support layer. 320 Attach the sample holder to the loading device. 330 Activate the retaining mechanism. 332 Rotating the lever 334 Rotating the eccentric element 336 Moving mechanical components 340 Insert the laminate into the sample holder. 342 To slide the laminate 350 Cutting off excess material 360 Insert the sample holder into the sample stage. 370 Aligning the laminate with the mask. 372 Aligning the laminate between the first and second dimensions. 374 Rotate the sample stage. 376 Aligning the laminate in a third dimension 380 Ion milling 382 Apply cooling 400 sample stages 410 masks 420 Sample holder 430 Lateral movement 435 Vertical movement 440 Set screw 450 Ion Gun
Claims
1. A sample holder (100), wherein the sample holder (100) is A main component (110) having a first surface region (112), A retaining mechanism (120) having a retaining component (122), Equipped with, The pressing mechanism (120) is configured to hold the sample (14) between the holding component (122) of the pressing mechanism and the first surface region (112) when the pressing mechanism is closed. The retaining mechanism is configured to be in an open state when the mechanical operation of the retaining mechanism is performed, and this open state allows for the insertion and removal of the sample. The retaining mechanism is configured to return to the closed state when the mechanical operation is released. Sample holder (100).
2. The retaining mechanism is configured to be in the open state when the mechanical components (210) of the loading device (200) are mechanically operated. The sample holder according to claim 1.
3. The aforementioned retaining mechanism includes a spring (124), the spring being compressed when the retaining mechanism is operated. A sample holder according to claim 1 or 2.
4. The pressing mechanism is configured to press down the laminate (10) containing the sample (14), the first surface region is provided to form a first boundary region with the longitudinal surface region (10a) of the laminate, and the main component further comprises a second surface region (114) provided to form a second boundary region with the transverse surface region (10b) of the laminate. A sample holder according to claim 1 or 2.
5. A loading device (200) for a sample holder, The loading device (200) includes a mechanical component (210) for activating the holding mechanism of the sample holder to open the holding mechanism of the sample holder, and the open state allows for the insertion of a sample into the sample holder and the removal of the sample from the sample holder. Loading device (200).
6. The loading device includes a first recess (230) for housing the sample holder. The loading device according to claim 5.
7. The loading device includes a stop surface region (235), the stop surface region being positioned such that when the sample holder is inserted into the first recess up to the stop surface region, the sample holder aligns with the mechanical components. The loading device according to claim 6.
8. The loading device includes a second recess (240) for guiding the insertion of a sample, such as a laminate containing the sample, into the sample holder. The loading device according to claim 6 or 7.
9. The loading device comprises a first portion having a first vertical height and a second portion having a second vertical height, wherein the first portion includes a first recess (230), and the second portion includes a second recess (240), and the second vertical height is greater than the first vertical height. The loading device according to claim 8.
10. The surface area of the second portion facing the first portion includes a stop surface area (235) for aligning the sample holder with the mechanical components. The loading device according to claim 9.
11. The loading device is provided with a screw thread (250) for housing a screw or bolt (255) for fixing the sample holder to the loading device. The loading device according to claim 5 or 6.
12. A method for inserting a sample into a sample holder for holding the sample during an ion milling process, wherein the method is Step (310) of placing the sample between a first support layer (12) and a second support layer (16) in order to form a laminate containing the sample, The step (340) of inserting the laminate into the sample holder, A method that includes this.
13. The method includes the step (350) of placing the sample between the first support layer and the second support layer, and then cutting off the excess material of the sample at the edges of the first support layer and the second support layer. The method according to claim 12.
14. One of the first support layer and the second support layer is provided with an inclined edge for aligning the laminate with a mask during the ion milling process. The method according to claim 12 or 13.
15. The method includes the step of ion milling the sample (380), wherein cooling is applied to the sample (382) via the first support layer and the second support layer and the surface region of the sample holder during the ion milling process. The method according to claim 12 or 13.