Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/02—Details
  • H01J37/20—Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/20—Positioning, supporting, modifying or maintaining the physical state of objects being observed or treated
  • H01J2237/208—Elements or methods for movement independent of sample stage for influencing or moving or contacting or transferring the sample or parts thereof, e.g. prober needles or transfer needles in FIB/SEM systems

Definitions

• the invention relates to a device for mounting a cassette with a lamellae holder and a method of operation thereof for use in particular in microscopy.
• lamella which is a part of the sample containing the area of interest.
• Such lamellae are usually created using a charged particle beam device, in particular using a focused ion beam. The whole process usually takes place in such a way that a sample containing the area of interest is inserted into the microscope. The said area of interest is found using a scanning electron microscope and a lamella is then created from the sample using a focused ion beam. The lamella thus created is transferred using a manipulator to a lamellae holder, where it can subsequently be further processed using a focused ion beam.
• the lamellae holder can further be held in a cassette.
• the lamella placed on the lamellae holder can then be transferred with this lamellae holder and optionally with the cassette to other observation or machining devices, such as a transmission electron microscope, ion polisher, etc.
• a broad ion beam with low energy penetrates only to a small depth and thus removes at least part of the damage to the lamella caused by the focused ion beam. Furthermore, due to the low energy, the broad ion beam does not create as much new damage to the lamella as compared to the focused ion beam.
• Known solutions provide a device with a broad ion beam which is made as a separate device, where it is necessary to move the lamella placed on the lamellae holder which is optionally placed in a cassette from the device with a focused ion beam to this device.
• Such a solution is unsuitable, since these are very small parts and the risk of mechanical damage is high, furthermore, the lamella may be contaminated during transport, and this solution is also time-consuming.
• Another known solution provides a device with a broad ion beam which is made as part of a system further containing a device with a focused ion beam. In such a solution, it is necessary to use a device for mounting the lamellae holder or the cassette, said mounting device allowing both processing using a device with a focused ion beam and a device with a broad ion beam.
• stages are usually used to mount the lamellae holder.
• stages for mounting the lamellae holder or cassette for systems containing a focused ion beam device and not containing a broad ion beam device are unsuitable for use in systems containing both a focused ion beam device and a broad ion beam device.
• the lamellae holder or cassette is usually fixedly (non-movably) mounted in such stages, so it is not possible to change their position and orientation depending on the device currently used for processing the lamella. This complicates the processing and preparation of the lamella, since in some cases collisions with devices located in the microscope chamber may occur.
• the broad ion beam has a large halfwidth of the track, so it is necessary that the processed lamella placed in the lamellae holder is distanced from other elements, e.g. stage, so that they are not irradiated by a broad ion beam and possible redeposition of the sputtered material on the lamella is prevented.
• other elements e.g. stage
• redeposition of the sputtered material on the lamella is prevented.
• the lamella can be placed close to the surface of the stage, since the footprint of the focused ion beam is sufficiently small and therefore does not irradiate the surrounding elements.
• a device for mounting a cassette with a lamellae holder comprising a body adapted to receive a sample holder with a sample on the surface of the body, wherein the device further comprises an arm which is rotatably connected to the body, and the end of the arm which moves away from the body when the arm is rotated is adapted to hold the cassette with the lamellae holder.
• the device for mounting the cassette fulfils the above-mentioned objectives by comprising a rotatable arm, the end of which, which is adapted to mount the cassette to which the lamellae holder is attached, moves away from the body of the device when the arm is rotated, thus creating a distance between the lamella which is attached to the lamellae holder attached to the cassette and the said body.
• the cassette mounting device also enables, by means of a rotary connection of the arm with the body, a change in the angle of rotation of the lamella relative to other elements, for example columns with charged particle sources, detectors or other elements located in the working chamber, when placing the cassette mounting device in the working chamber of the device with a charged particle beam, as described below.
• the body and the arm are further adapted so that the arm is rotatable relative to the body around an axis of rotation into at least two fixed positions, with the arm forming an angle of 0° with the body surface in the first position and an angle of 90° in the second position.
• the advantage of rotatability into two fixed positions of 0° and 90° is that in these positions the distance between the body and the end of the arm with the mounted cassette is the smallest or the largest, which is advantageous for irradiation with various types of charged particle beams.
• the device for mounting a cassette with a lamellae holder further comprises an arm locking mechanism adapted to lock the arm in fixed positions.
• the arm comprises an element for rotating the arm, the element for rotating the arm being any element from the group of a recess, a hole or a pin.
• the end of the arm is adapted to allow the cassette to be mounted so that the side of the cassette with the largest area forms an angle of 90° with the axis of the arm.
• a device with a charged particle beam comprising a device for mounting the cassette, and at least one column and a working chamber connected to the column, wherein the column contains a source of charged particles and is adapted to create and direct the charged particles, and further comprising a stage displaceable in at least two axes, rotatable about a central axis and tiltable about at least one axis perpendicular to the central axis, wherein the said device comprises a device for mounting the cassette with a lamellae holder, having a body placed on the stage, wherein the device with a charged particle beam further comprises a manipulation element located in the working chamber, the free end (the end which is not connected to anything further) of which forms a counterpart to the element for rotating the arm.
• the free end is an end which is not connected to anything.
• the charged particle beam device achieves the above-mentioned objectives by having a device for mounting a cassette placed on a stage, thereby enabling the processing of the lamella using different charged particle beams, since different charged particle beams preferably require a different arrangement and orientation of the lamella relative to other elements, as mentioned above.
• the manipulation element is separately and immovably located in the working chamber, thereby reducing the risk of inaccuracy in adjusting the position of the manipulation element relative to the body or the arm rotation element.
• the manipulation element is attached to the column.
• the charged particle beam device is a broad ion beam device.
• the charged particle beam device includes at least two columns.
• the body and the stage are adapted for mutual sliding arrangement, wherein the body is displaceable with respect to the stage between at least two fixed positions, wherein in the first fixed position, the lamella is located approximately on the axis of rotation of the stage and is held in the lamellae holder held in the cassette, and in the second fixed position, the body is located with respect to the stage in a position different from the first fixed position.
• the advantage of the possibility of moving the body with respect to the stage is the possibility of optimizing the position of the body with respect to the stage when processing the lamella or sample with different types of charged particle beams, since a different position of the body with respect to the stage is more advantageous for each type of processing, for example, when creating a lamella from a sample and transferring it to the lamellae holder, it is advantageous to have the center of the body at the center of the stage, but when processing the lamella using a broad ion beam, it is advantageous to have the center of the lamella at the center of the stage.
• a method of changing the position of the arm of a device for mounting a cassette with a lamellae holder wherein in the first step of changing the position of the arm, the stage with the body is moved so that the manipulation element comes into contact with the element for rotating the arm, in the second step of changing the position of the arm, the stage with the body is moved so that the arm rotates to the opposite fixed position than the one in which it is in the first step, while during the movement the manipulation element remains in contact with the element for rotating the arm, in the third step of changing the position of the arm, the stage with the body is moved so that the manipulation element and the element for rotating the arm are no longer in contact.
• the advantage of this method of changing the position of the arm is that it is not necessary to use a separately movable manipulation element, thus eliminating inaccuracies in adjusting its position and the need for an additional actuator, since sufficient movement options are already provided by the movable stage.
• a method of changing the position of the body of a device for mounting a cassette with a lamellae holder consisting in that in the first step of changing the position of the body, the stage with the body is moved so that the manipulation element comes into contact with the body, in the second step of changing the position of the body, the stage is moved so that the body remains in contact with the manipulation element and only the stage moves with respect to the working chamber, namely by moving it relative to the body to the opposite fixed position of the body than the one in which it is located in the first step, and in the third step of changing the position of the body, the stage with the body is moved so that the manipulation element and the body are no longer in contact.
• Fig. 1 shows a device for mounting a cassette with a lamellae holder in a position where the arm axis forms an angle of approximately 0° with the body surface;
• Fig. 2 shows a device for mounting a cassette with a lamellae holder in a position in which the arm axis forms an angle of approximately 90° with the body surface;
• Fig. 3 shows a pin whose axis forms the axis of rotation of the arm and an arm locking mechanism
• Fig. 4 shows a detail of a device with a beam of charged particles with a body placed on a stage in a position in which the arm axis forms an angle of approximately 0° with the body surface;
• Fig. 5 shows a detail of a device with a beam of charged particles with a body placed on a stage in a position in which the arm axis forms an angle of approximately 90° with the body surface;
• Fig. 6 shows a detail of a device with a beam of charged particles with a body placed on a stage in a position in which the body is in a second fixed position relative to the stage;
• Fig. 7 shows a detail of a device with a beam of charged particles with a body placed on a stage in a position in which the body is in a first fixed position relative to the stage;
• Fig. 8 is a detail of a cassette in one embodiment and its mounting to the arm and a lamellae holder;
• Fig. 9 is a detail of a cassette in another embodiment and its mounting to the arm and a lamellae holder;
• Fig. 10 is a schematic illustration of a device with a beam of charged particles and a device for mounting a cassette with a lamella holder;
• Fig. 11 shows a stage with a body and a column to which a manipulation element is connected, in a position where the stage with the body and the arm is distant from the manipulation element and the arm is in a position where the arm axis forms an angle of approximately 0° with the body surface;
• Fig. 12 shows a stage with a body and a column to which a manipulation element is connected, in a position where the stage with the body and the arm is relative to the manipulation element such that the end of the manipulation element is inserted into the arm rotation element and the arm is in a position where the arm axis forms an angle of approximately 0° with the body surface
• Fig. 13 shows a stage with a body and a column to which a manipulation element is connected, in a position where the stage with the body and the arm is relative to the manipulation element such that the end of the manipulation element is inserted into the arm rotation element and the arm is in a position where it transitions from one fixed position to another fixed position relative to the body;
• Fig. 14 shows a stage with a body and a column to which a manipulation element is connected, in a position where the stage with the body and the arm is relative to the manipulation element such that the end of the manipulation element is inserted into the element for rotating the arm and the arm is in a position where the axis of the arm forms an angle of approximately 90° with the body surface;
• Fig. 15 shows a stage with a body and a column to which a manipulation element is connected, in a position where the stage with the body and the arm is distant from the manipulation element and the arm is in a position where the axis of the arm forms an angle of approximately 90° with the body surface;
• Fig. 16 shows a stage with a body and a column, in a position where the body with the stage is distant from the manipulation element and the body is in a second fixed position relative to the stage;
• Fig. 17 shows a stage with a body and a column, in a position where the body is in contact with the manipulation element and the body is in a second fixed position relative to the stage;
• Fig. 18 shows a stage with a body and a column, in a position where the body is in contact with the manipulation element and the body is in a first fixed position relative to the stage;
• Fig. 19 shows a stage with a body and a column, in a position where the body with the stage is distant from the manipulation element and the body is in a first fixed position relative to the stage.
• An example of an embodiment of the invention is a device for mounting a cassette 4 with a lamellae holder 5 as shown in Figures 1 to 19 and a charged particle beam device containing a device for mounting a cassette 4 shown in Figures 4 to 7 and 10 to 19.
• the device for mounting a cassette 4 with a lamellae holder 5 consists of a body 1 and an arm 3.
• the body 1 is adapted for placing a sample holder 2 with a sample 12 on the surface of the body 1 as seen in Figure 3.
• Such an adaptation is, for example, a recess 13 in the surface of the body 1 for placing a sample holder 2 with a sample 12, wherein this sample holder 2 is provided with a pin on the opposite side of the sample holder 2 than the spot for placing the sample 12 and the dimensions of this pin correspond to the said recess 3.
• the arm 3 is rotatably connected to the body 1 about an axis of rotation perpendicular to the axis of the arm 3.
• the axis of the arm 3 is understood to be the longest axis.
• the rotating connection is realized, for example, by means of a pin 14 passing through the arm 3 and attached to the body 1, see figure 3.
• the rotating connection is attached to the body 1 on the surface of the body T
• the rotating connection is attached to the body 1 below the surface of the body 1.
• the arm 3 is rotatable relative to the body 1 into at least two fixed positions, see figures 1 and 2 and 1 1 to 15.
• the axis of the arm 3 In the first fixed position of the arm 3, the axis of the arm 3 forms an angle of approximately 0° with the surface of the body 1, see figures 1 , 1 1 and 12. In the second fixed position of the arm 3, the axis of the arm 3 forms an angle of approximately 90° with the surface of the body 1, see figures 2, 14 and 15.
• the locking of the arm 3 in the fixed positions is performed in the first example embodiment by means of a ball latch 1_5, see Figure 3.
• the locking of the arm 3 in fixed positions can be performed using any mechanism that allows automatic engagement and release of the arm 3 when a sufficient amount of force is applied, but without damaging the mechanism.
• the locking mechanism of the arm 3 is located along the axis of the arm 3 above or below the axis of rotation of the arm 3.
• the arm 3 further includes an element 6 for rotating the arm 3.
• the element 6 for rotating the arm 3 is any element selected from a recess, a hole or a pin.
• the axis of the element 6 for rotating the arm 3 is oriented parallel to the axis of rotation of the arm 3.
• the end of the arm 3, which moves away from the surface of the body 1 when the arm 3 is rotated, is adapted to mount the cassette 4.
• the cassette 4 can be mounted, for example, by means of prestressed clamps, screw clamps or by means of any other method of mounting that allows automatically or manually detachable mounting of the cassette 4.
• the cassette 4 is also adapted so that the side of the cassette 4 with the largest area, when the cassette 4 is mounted in the cassette 4 holder, forms an angle of 90° with the axis of the arm 3. In other words, if the axis of the arm 3 forms an angle of 0° with the surface of the body 1, the largest area of the cassette 4 mounted in the cassette holder forms an angle of 90° with the surface of the body 1_. In the case where the axis of the arm 3 forms an angle of 90° with the surface of the body 1, the largest surface of the cassette 4 mounted in the cassette holder forms an angle of 0° with the surface of the body 1.
• the cassette 4 is also adapted to mount the lamellae holder 5, on which the lamella is subsequently placed.
• the cassette 4 is adapted to mount the lamellae holder 5 in such a way that it allows the lamella to be processed using a focused ion beam and using a broad ion beam.
• the cassette 4 is adapted so that in the vicinity of the lamellae holder 5 (the vicinity is limited by five times the half-width of the broad ion beam track), there is a minimum number of surfaces on which the broad ion beam can impinge when processing the lamella.
• the cassette 4 is adapted as shown in Figure 8 or Figure 9.
• the cassette 4 is always adapted so that the lamellae holder 5 is contacted only by two retaining elements 17, the length of which is such that the rest of the cassette 4 is at a distance greater than two half-widths of the broad ion beam spot from the center of the lamella holder 5, while the shape and size of the retaining elements 17, on which the broad ion beam impinges when processing the lamella using the broad ion beam, is such that the lamellae holder 5 is held so firmly that it cannot be released spontaneously during various movements and orientations of the stage 1_1_, the body 1 and the arm 3, but at the same time so that the lamellae holder 5 can be removed or inserted as desired from the cassette 4.
• An example embodiment of the invention is further a charged particle beam device with a device for mounting a cassette 4 as shown in figures 4 to 7 and 10 to 19.
• the charged particle beam device comprises at least one column 7 and a working chamber 8 connected to the column 7.
• the column 7 comprises a source 9 of charged particles.
• the column 7 with a source 9 of charged particles is a column with an ion source adapted for irradiation using a focused ion beam, or an ion column with an ion source adapted for irradiation using a broad ion beam.
• the column 7 is connected to the working chamber 8 so that the charged particle beam emitted from the column 7 outlet enters the working chamber 8.
• the charged particle beam device also comprises an electron column for observation using an electron beam scanned over the sample 12 or over the lamella in two mutually perpendicular axes.
• the charged particle beam device further comprises a stage 11 movable in at least two mutually perpendicular axes, rotatable about a central axis and tiltable about at least one axis perpendicular to the central axis.
• the stage is displaceable in at least three mutually perpendicular axes and rotatable about a central axis and tiltable about at least one axis perpendicular to the central axis.
• the charged particle beam device in another example embodiment of the charged particle beam device further comprises a transition chamber connected to the working chamber 8, wherein between the working chamber 8 and the transition chamber there is a gate adapted to maintain a different pressure in the working chamber 8 and in the transition chamber in the closed state or for free connection of both chambers in the open state.
• the transition chamber further comprises a sliding element, the end of which in one of the positions is located in the transition chamber and in the other position the same end is located in the working chamber 8.
• the manipulation element 10 is on one side immovably connected to another element in the working chamber 8, which is the column 7, the working chamber 8 itself or any other suitable element, which is not the stage 11 .
• the individual immobility of the manipulation element 10 means that the manipulation element 10 itself is not equipped with any actuator, which could move it independently of the other elements, but if the manipulation element 10 is connected, for example, to a movable column 7, the manipulation element 10 will move with this column 7.
• the manipulation element 10 is adapted to form a counterpart of the element 6 for rotating the arm 3.
• the ..counterpart implies such a shape of the manipulation element 10 that allows the manipulation element 10 to be inserted into a recess or hole forming the element 6 for rotating the arm, for example a cylindrical shape, or in the case where the element 6 for rotating the arm 3 is a pin, the manipulation element 10 has the shape of a hollow cylinder with an inner diameter approximately corresponding to the diameter of the pin.
• the body 1 is placed on the stage Ij..
• the body 1 and the stage 1 1 are adapted for mutual sliding placement, whereby the body 1 is displaceable relative to the stage 11 between at least two fixed positions, see figures 6 and 7 and 16 to 19.
• Such an adaptation for mutual sliding placement is, for example, a guide groove in the stage 1 1 and the corresponding shape of a guide insert on the body 1-
• a lamella In the first fixed position, a lamella is located approximately on the axis of rotation of the stage 1_L, held in the lamellae holder 5 mounted in the cassette 4, and in the second fixed position, the body 1 is located relative to the stage 1 1 in a position different from the first fixed position.
• the ..approximate position" on the axis of rotation refers to a tolerance within ⁇ 0.2 half-widths of a broad ion beam spot from the exact position.
• the ..position different from the first fixed position refers to a position where the body 1 is still on the stage Ij., but its position is different from the first fixed position.
• the second fixed position is defined in one of the example embodiments, for example, by a stop 16 in the guide groove of the stage Ij., as shown for example in Figures 6 and 7.
• Holding the body 1 relative to the stage 1 1 in fixed positions is, in the first example embodiment of the method of holding the body 1 relative to the stage Ij., performed by means of increased friction between, for example, the guide groove and the guide insert, to such an extent to allow moving the guide insert in the guide groove when using another element exerting a force against or on the body 1, but the guide insert alone does not start moving in the guide groove.
• the holding is performed using a ball latch.
• the holding is performed using any other mechanism allowing automatic capture and release of the body 1 relative to the stage 1 1 when a sufficient amount of force is applied, but without damaging the mechanism.
• the sliding arrangement is further adapted so that the body 1 can be ejected, for example, from the guide groove of the stage 11 and if the charged particle beam device includes a transition chamber with a sliding element, the sliding element can be adapted to receive the body 1 ejected from the stage 1j_.
• a first step of the method of changing the position of the arm 3 the stage 11 with the body 1 is moved so that the manipulation element 10 comes into contact with the element 6 for rotating the arm 3, see figures 1 1 and 12. In this step, therefore, regardless of the current position of the stage 1 1 within the working chamber 8, the stage 1 1 is moved so that the manipulation element 10 comes into contact with the element 6 for rotating the arm 3, for example, the manipulation element 10 is inserted into the hole in the arm 3.
• the stage 11 with the body 1 is moved so that the arm 3 rotates to the opposite fixed position than the one in which it is in the first step, while during the movement the manipulation element 10 remains in contact with the element 6 for rotating the arm, see figures 13 and 14.
• the arm 3 In this step, if the arm 3 is in the first fixed position of the arm 3 in relation to the body 1, it moves to the second fixed position of the arm 3 and, vice versa, if it is in the second fixed position of the arm 3, it moves to the first fixed position of the arm 3.
• the manipulation element 10 in contact with the element 6 for rotating the arm does not move, but the arm 3 rotates around the manipulation element 10 due to the movement of the stage H, for example, the arm 3 rotates around the manipulation element 10 inserted into the hole in the arm.
• the stage 1 1 with the body 1 is moved so that the manipulation element 10 and the element 6 for rotating the arm are no longer in contact, see figure 15.
• the stage 11 and simultaneously the body 1 with the arm 3 and the element 6 for rotating the arm 3 are moved away from the manipulation element , for example, the manipulation element 10 is ejected from the hole in the arm 3.
• a first step of the method of changing the position of the body 1 relative to the stage 1_1_ the stage 1 1 is moved with the body 1 so that the manipulation element 10 comes into contact with the body 1, see figures 16 and 17.
• the stage 11 is moved so that the manipulation element 10 comes into contact with the body 1, while the place where the manipulation element 10 comes into contact with the body 1 is any suitable place that allows the stage 11 to be moved relative to the body 1 without the need for the body 1 to be interconnected with the manipulation element 10.
• the place where the manipulation element 10 comes into contact with the body 1 is any suitable place that allows to use pushing the manipulation element 10 relative to the body 1, and when the manipulation element 10 is approximately perpendicular to the direction of movement of the body 1_re lati ve to the stage H, also to use pulling the manipulation element 10 relative to the body 1, to change the position of the stage 11 relative to the body 1.
• the stage 1 1 is moved so that the body 1 remains in contact with the manipulation element , and only the stage 11 moves relative to the working chamber 8, namely by moving it to the opposite fixed position of the body 1 than the one in which it was located in the first step, see Figure 18.
• the body 1 if the body 1 is in the first fixed position of the body 1 relative to the stage 1_, it moves to the second fixed position of the body 1, and vice versa, if it is in the second fixed position of the body 1, it moves to the first fixed position of the body 1. In other words, during the movement to the opposite fixed position, the moving stage 1 1 presses the body 1 against the manipulation element 1.0, which causes it to move to the opposite fixed position of the body 1.
• the stage 11 and the body 1 are moved so that the manipulation element 10 and the body 1 are no longer in contact, see Figure 19. In this step, the stage 1 1 and simultaneously the body 1 are moved away from the manipulation element 10.
• the manipulation element 10 is rotatable around its own axis and the element 6 for rotating the arm 3 is located on the axis of rotation of the arm 3 and is adapted so that after the manipulation element 10 comes into contact with the element 6 for rotation of the arm 3, by rotating the manipulation element 10 around its axis, the arm 3 also rotates simultaneously.

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Citations (1)

• 2023
  • 2023-12-13 CZ CZ2023-483A patent/CZ2023483A3/cs unknown
• 2024
  • 2024-12-11 WO PCT/CZ2024/050082 patent/WO2025124626A1/en active Pending

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