Material processing method and material processing system for performing the method

Abstract

A material processing system includes a particle beam column for guiding a particle beam to a first processing area and a laser scanner for guiding a laser beam to a second processing area. A method for operating the material processing system includes: scanning a first mark placed on an object with the particle beam; first scanning the first mark with the laser beam and generating a second mark on the object with the laser beam; scanning the second mark with the particle beam; and, based on scanning the second mark with the particle beam, second scanning the first mark with the laser beam and removing material from the object with the laser beam.

Description

Technical Field

[0001] The present invention relates to a material processing method and a material processing system for performing the material processing method. Background Technology

[0002] Conventional material processing systems include an electron microscope with an electron beam column for scanning an electron beam over a first processing region of an object and detecting electrons generated at the object by the scanning electron beam to produce an electron microscope image of the object. Conventional systems also include an ion beam column for guiding an ion beam to a selectable location within the first processing region to remove material from the object at that location. The material processing system can be used to expose a region of interest on an object by removing material with an ion beam, enabling the generation of an electron microscope image of the exposed region of interest. For example, the region of interest in the object may be a packaged integrated circuit or a circuit element within a potted integrated circuit.

[0003] Material removal using ion beams is precisely controllable, meaning that even small or thin structures can be exposed in desired areas of an object. However, the material removal rates achievable with ion beam processing are relatively low, resulting in significant time consumption for exposing regions of interest located beneath the object's surface.

[0004] Therefore, conventional material processing systems also include a laser scanner that guides a laser beam to a selectable location in a second processing area to remove material from an object at a greater removal rate than that achievable with an ion beam when the object is positioned in the second processing area.

[0005] Although the material removal rate achievable with a laser beam is greater than that achievable with an ion beam, the accuracy achievable during material removal with a laser beam is significantly lower than that achievable with an ion beam. For this reason, a laser beam is used to remove material from an object in a manner that leaves the region of interest (ROI) covered by remaining material, which is retained as a protective measure against damage to the RPI. This retained material is then removed using an ion beam to expose the RPI. Since the material removal rate of an ion beam is lower than that of a laser beam, removing the remaining material retained as a protective measure also requires a significant amount of time, and it is desirable to reduce this time. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a material processing method and a corresponding material processing system, wherein material can be removed by laser beam and by ion beam in a relatively short period of time to expose the region of interest on an object.

[0007] The present invention proposes a material processing method for a material processing system, the material processing system including at least one particle beam column and a laser scanner.

[0008] According to an embodiment of the invention, the at least one particle beam column is configured to guide at least one particle beam to a first processing area, and the laser scanner is configured to guide a laser beam to a second processing area. The second processing area may overlap with the first processing area. To avoid contamination of the electron beam column and / or ion beam column by particles that may be generated during the processing of an object with the laser beam, the second processing area may be arranged at a distance from the first processing area. If necessary, other possible features (such as baffles that can be specifically positioned as needed) may also provide protection against such contamination.

[0009] According to an embodiment, the at least one particle beam column includes an electron beam column configured to guide an electron beam to a first processing region. The electron beam can be used to remove material from an object disposed in the first processing region. For this purpose, the material processing system may include a process gas supply device to supply a suitable process gas that can be activated by the electron beam to the first processing region for material removal from the object by etching. Electron beam scanning can also be performed over a scanning region contained in the first processing region, wherein signals generated by the electron beam incident on the object during scanning (such as backscattered electrons) are detected to generate an electron microscope image representing, for example, the signal intensity detected in a spatially resolved manner. In this case, the electron beam column provides the functionality of an electron microscope.

[0010] The at least one particle beam column may also include an ion beam column configured to guide the ion beam to a first processing region. The ion beam can be used to remove material from an object disposed in the first processing region, for which process gases can also be supplied. The ion beam can also be used to generate signals (such as electrons) at the object, and these signals can be detected to generate an image based on the intensity of the generated signals (detected in a spatially resolved manner). In this case, the ion beam column provides the functionality of an ion microscope.

[0011] According to an exemplary embodiment, the material processing system includes both an electron microscope and an ion beam column, which are arranged such that both the electron beam and the ion beam can be guided to at least a plurality of portions of a first processing region.

[0012] The laser scanner is configured to guide a laser beam to a selectable location within a second processing area. Specifically, the laser beam can be turned on and off, and can be turned on to remove material from the object if the laser scanner's beam path is set such that it is guided to a desired location on the object. The laser beam can be a pulsed laser beam. Specifically, the pulse duration of the generated laser pulse can be in the nanosecond range. According to an exemplary embodiment, the pulse duration is in the femtosecond range. Within such a short pulse duration, relatively precise material processing can be achieved because the material incident on the surface of the object by the laser beam is removed through evaporation and other mechanisms, while the large volume of material remaining on the object is not damaged or destroyed by thermal effects. Therefore, laser scanners that generate short laser pulses (e.g., in the femtosecond range) are particularly suitable for use in embodiments of material processing systems and methods, as material removal with the laser beam can be performed up to a location immediately adjacent to the region of interest.

[0013] According to an exemplary embodiment, the material processing method includes first scanning a first mark placed on an object with a laser beam, and then generating a second mark on the object with the laser beam. Prior to the first scanning of the first mark, the object can be moved to a second processing area using a transport system. According to an exemplary embodiment, the first mark is already placed on the object at this point.

[0014] According to an exemplary embodiment, scanning the first mark with the laser beam for the first time includes determining the position of the first mark in the coordinate system of the laser scanner. This means that the first mark is configured to be recognizable as a mark when scanned with a laser beam by means of a laser scanner, resulting in the determination of the position of the first mark in the coordinate system of the laser scanner.

[0015] A second mark is generated on an object using a laser beam, for example, by removing material from the object using a laser beam, wherein the volume of the removed material has a predetermined shape, such as a line, a cross, multiple dots, or another geometric shape. According to an exemplary embodiment, the second mark generated by the laser beam is not necessarily suitable for recognition as a mark by a laser scanner. According to an exemplary embodiment, generating the second mark includes fixing a position in the coordinate system of the laser scanner based on scanning a first mark with the laser beam, and guiding the laser beam to that position determined in the coordinate system of the laser scanner. This position in the coordinate system of the laser scanner can be based on, for example, a model of the object's geometry. The model of the object's geometry can be, for example, a CAD model of the object or an image of the object, which is registered to the coordinate system of the laser scanner based on the determined position of the first mark.

[0016] According to an exemplary embodiment, the material processing method further includes scanning the first mark with the at least one particle beam. According to an exemplary embodiment, before scanning the mark with the at least one particle beam, an object is moved to a first processing area by a transport system. The first mark can be scanned with the at least one particle beam before or after scanning the first mark with a laser beam and generating a second mark with a laser beam.

[0017] According to an exemplary embodiment, the material processing method further includes scanning the second mark with the at least one particle beam. According to an exemplary embodiment, before scanning the second mark with the at least one particle beam, the object is moved to the first processing area by a transport system.

[0018] According to an exemplary embodiment, scanning the first marker with the at least one particle beam includes determining the position of the first marker in the coordinate system of the at least one particle beam column. Therefore, scanning the second marker with the at least one particle beam may include determining the position of the second marker in the coordinate system of the at least one particle beam column. This means that, during scanning with the at least one particle beam, both the first marker and / or the second marker can be identified as markers in their respective cases. This is, for example, if the first or second marker in the particle optical image (generated during scanning with the particle beam) can be identified with sufficient contrast. According to an exemplary embodiment, the first marker may be identified as a marker when scanned with a laser beam, while the second marker does not necessarily need to be identifiable or detectable by scanning with a laser beam. For this purpose, the first marker may include, for example, a combination of a photodetector for detecting the light of the laser beam and a mechanical baffle that partially blocks the photodetector.

[0019] According to an exemplary embodiment, the material processing method further includes determining the position of the second mark relative to the first mark based on scanning the first mark and scanning the second mark with the at least one particle beam.

[0020] According to an exemplary embodiment, the markers used in the method (i.e., the first marker and / or the second marker) can be configured such that the position and orientation of the marker in the coordinate system of the laser scanner and the coordinate system of the at least one particle beam column can be determined. For this purpose, the markers can have a spatial extent and a predetermined geometry, such as, for example, a horizontal bar, a cross, a circle, a triangle, or another geometric shape. In particular, the markers can also comprise multiple portions, which can be arranged as partial markers spaced a distance from each other. For example, two, three, or more partial markers can be provided. In this case, these partial markers can be configured such that their orientation cannot be determined by means of the laser beam or the at least one particle beam column. However, the orientation of a marker comprising multiple such partial markers can be determined by scanning with a laser scanner or by scanning with the at least one particle beam.

[0021] According to an exemplary embodiment, the material processing method further includes scanning the first mark a second time with a laser beam based on scanning the first mark with the at least one particle beam and scanning the second mark with the at least one particle beam, and removing material from the object with the laser beam. As a result, material removal using a laser beam can achieve very high precision, and thus particularly reach the region of interest immediately adjacent to the object.

[0022] According to an exemplary embodiment, the material processing method includes removing material from an object using a laser beam, and then removing material from the object using the at least one particle beam. The particle beam used here may be an ion beam or an electron beam. Removing material from the object using the at least one particle beam exposes a region of interest within the object. Therefore, the material processing method may further include scanning at least a portion of the object with the at least one particle beam after removing material from the object, and detecting a signal generated at the object due to the particle beam scanning. The particle beam used for scanning the portion of the object with the at least one particle beam may be an electron beam or an ion beam. The material processing method may then further include generating an image based on the detected signal and presenting the generated image using a display medium such as a screen. The material processing method may also include storing the generated image in a storage medium (e.g., a hard disk drive, a solid-state drive, or cloud storage).

[0023] Because removing material from an object with a laser beam can achieve very high precision, the material can be removed up to a position very close to the region of interest, where, for protection purposes, only a very small or thin volume of material remains in front of the region of interest. This very small or thin volume of material can then be removed in a relatively short time using at least one particle beam to expose the region of interest, and an image can be generated from it, for example, by scanning with the at least one particle beam.

[0024] According to an exemplary embodiment, the material processing method includes fixing a position in the coordinate system of a laser scanner relative to the position of a first mark (determined based on scanning the first mark with a laser beam), and guiding a laser beam to that position to generate a second mark. This position can be fixed, for example, based on a model of the object's geometry (e.g., a CAD model of the object). The method may then further include determining the position of the second mark relative to the first mark based on scanning the second mark with the at least one particle beam. If, during the generation of the second mark, the laser beam is indeed guided to a specific position on the object by means of a laser scanner, the location of the position to which the laser beam is guided should correspond to the location of the fixed position. In practice, technical defects in the system used (such as defects in the optical unit and laser beam alignment of the laser scanner, thermal effects, and inaccurate adjustments) cause the laser beam to be guided to a position deviating from the fixed position when it is perceived to be guided there. Therefore, the laser beam may not necessarily generate the second mark at the fixed position, but rather at a position where its location differs slightly from the location of the fixed position. This deviation can be determined by scanning the second mark with the at least one particle beam. Therefore, this method can further provide the fact that the material removal of an object by a laser beam is based on the difference between the position of the second mark (determined by scanning the second mark with the at least one particle beam) and the positioning of the position fixed for generating the second mark with the laser beam. In particular, the laser beam can be aligned with the position intended for material removal based on said difference.

[0025] According to an exemplary embodiment, the method involves scanning the first mark with the at least one particle beam and scanning at least a portion of the object with the at least one particle beam before first scanning the first mark with the laser beam and before generating the second mark. Prior to this step, the object may have been moved to a first processing area using a transport system. By scanning the portion of the object with the at least one particle beam, the surface shape of that portion of the object and the position and orientation of the object's surface relative to the region of interest can be captured. Therefore, the method can then include fixing a position on the surface of the object relative to the position of the first mark, the position of which is determined based on scanning the first mark with the at least one particle beam, wherein the fixing is based on scanning the portion of the object with the at least one particle beam. Then, in the coordinate system of the laser scanner, a position can be fixed in the coordinate system of the laser scanner (to which the laser beam is guided to generate the second mark) based on scanning the first mark with the laser beam and based on the fixed position. In this way, precise alignment of the volume of material to be removed by the laser beam with respect to the region of interest of the object can be achieved. Attached Figure Description

[0026] Embodiments of the present invention will now be explained in more detail with reference to the accompanying drawings, in which:

[0027] Figure 1 A schematic cross-section of a material processing system according to an embodiment is shown;

[0028] Figure 2 It shows Figure 1 A schematic top view of the sample holder of the material processing system shown;

[0029] Figure 3 A flowchart illustrating a material processing method according to a first embodiment is shown; and

[0030] Figure 4 A flowchart illustrating a material processing method according to a second embodiment is shown. Detailed Implementation

[0031] Figure 1 This is a schematic diagram of the material processing system 1 according to an embodiment.

[0032] The material processing system 1 includes two particle beam columns, specifically an electron beam column 3 for generating an electron beam 5 and an ion beam column 7 for generating an ion beam 9, which, like the electron beam 5, is guided to a selectable position within the scanning region 11.

[0033] Electron beam column 3 is used to guide electron beam 5 to the region of interest of the object arranged within processing area 11, and to detect secondary electrons or backscattered electrons. When electron beam 5 is guided to different positions on the object and the detected intensity is distributed to these positions, electron microscope images of the region of interest of the object can be generated.

[0034] Ion beam column 7 is used to guide ion beam 9 to selected locations. Ion beam 9 can remove material from the object at these locations. A process gas can also be supplied to the processing location here, which is activated by the ion beam and causes material removal from the object. Then, similar to an electron beam, the ion beam can also be used to generate an image of the object.

[0035] Material can only be removed from an object at a limited rate using the ion beam 9. If the desired material removal range results in too much time being taken at a given removal rate using the ion beam, a laser beam can be used for material removal. For this purpose, the object is transported to the processing area 13 of the laser beam 17 emitted by the laser scanner 15 so that material can be removed from the object using the laser beam 17. The material removal rate using the laser beam 17 is greater than that using the ion beam 9. Therefore, a relatively large material removal rate can be achieved using the laser beam 17.

[0036] The electron beam column 3 includes an electron source 21 having a cathode 23 and an anode 25, a condenser lens system 27 for generating the beam 5, a secondary electron detector 29 arranged, for example, within the column 3, and an objective lens 31 for focusing the electron beam 5 into the processing area 11. A beam deflector 33 is provided to change the incident position of the electron beam 5 on the object, and to scan, for example, the scanning area 11, and to detect, with the detector 29, the signals generated or released during this process (secondary electrons in this exemplary embodiment) in order to obtain an electron microscope image of the object in the scanned scanning area 11.

[0037] The ion beam column 7 includes an ion source 39, an electrode 41 for shaping and accelerating the ion beam 9, a beam deflector 43, and a focusing coil or focusing electrode 45 for focusing the ion beam 9 into the processing area of ​​the electron beam column 3 and for scanning the ion beam over the area of ​​the object.

[0038] Vacuum chamber 51 is defined by vacuum sleeve 53, which has a pump connector 55 connected to a vacuum pump and can be vented via connector 57. To permanently maintain electron source 21 under a sufficiently good vacuum (even when process gases are introduced into vacuum chamber 51), electron beam column 3 includes pressure stage baffles 59 and additional pump connector 61 to allow for pumping of the electron source 21 using a separate vacuum pump. The shared processing area of ​​electron beam column 3 and ion beam column 7 is arranged within vacuum chamber 51.

[0039] The laser scanner 15 includes a laser 71 and an optical unit 73 for shaping and focusing a laser beam 17. The laser beam 17 is guided via one or more mirrors 75 or one or more light guides to a position adjacent to the vacuum sleeve 53 of the vacuum chamber 83, and therein it is incident on one or more pivot mirrors 77, which guide the beam to the object to be processed and are pivotable in the process (as indicated by arrow 79) so that the beam 17 can scan the processing area 13.

[0040] In this configuration, the laser beam 17 enters the vacuum chamber 83 through the window 81. This vacuum chamber is also defined by the chamber wall 53, but can be separated from the vacuum chamber 51 by an openable door 85. Figure 1 The closing plate 87 of door 85 in the open state is shown in solid lines, and the closing plate of door 85 in the closed state is shown in dashed lines. The actuator rod 89 of the door is used to move the closing plate 87 to switch door 85 from its open state to its closed state and vice versa. Here, door 85 can be implemented as a vacuum seal relative to chamber wall 53 to maintain different vacuum pressures in vacuum chambers 51 and 83. Here, vacuum chamber 83 is evacuated via pump connector 91 connected to a vacuum pump and can be vented via another connector 93.

[0041] The object to be processed is mounted on the object holder 101 and can be transported between two locations together with the object holder 101. For this purpose, a transport device 103 is provided with a link 105, one end of which has a connector 108 through which the object holder 101 is gripped, so as to move the object holder from... Figure 1 The position on the right (where the object is positioned within the processing areas of particle beams 5 and 9) is pulled to... Figure 1 The left-hand position (in which the object is positioned within the processing area 13 of the laser beam 17). The object holder 101 can also be moved from the left-hand position using the transport device 103. Figure 1 Transported to the left side Figure 1 The position on the right. For this purpose, the transport device 103 also includes a vacuum seal 107 disposed in the vacuum sleeve 53 (through which the connecting rod 105 passes), and this vacuum seal allows the connecting rod 105 to be displaced to transport the object holder 101 between its two positions without venting the vacuum chambers 51 and 83. A guide rail 109 may also be provided to carry the object holder 101 during transport. When the object holder 101 is arranged in… Figure 1 When in the position of the vacuum chamber 51 on the right, the connecting part 108 of the connecting rod 105 can be released from the object holder 101, so that the connecting rod 105 can be removed from the vacuum chamber 51 and the door 85 can be closed.

[0042] When the object holder 101 is arranged in the vacuum chamber 51, it is carried by a positioning device 111 for moving the object holder 101 relative to the particle beams 5 and 9 to move a selectable region of the object into the scanning region 11 of the electron beam column 3 or the scanning region of the ion beam column 7. For this purpose, the positioning device 111 includes a base 113 and one or more intermediate components 115 that carry the component 117 to which the object holder 101 is secured. Components 113, 115, and 117 are movable relative to each other to allow the object holder 101 to be displaced in three spatial directions x, y, and z, and these components are also rotatable relative to each other to allow changes in the orientation of the object holder 101 relative to the particle beams 5 and 9. Figure 1 In the vacuum chamber 83 on the left, an object holder 101 is positioned on a positioning device 122, which allows the object holder 101 to be positioned within the processing area 13 of the laser scanner 15. The transport device 103, positioning device 111, and positioning device 122 together form a transport system for moving objects between the processing areas of the particle beam columns 3 and 7 and the processing area of ​​the laser scanner 15, and for positioning the desired area of ​​the object within the scanning areas of the particle beam columns 3 and 7 and the scanning area of ​​the laser scanner 15, respectively.

[0043] For example, background information relating to systems that use multiple particle beams and a laser beam to process objects can be found in the public documents US2010 / 0051828 A1 and US2011 / 0198326 A1, the disclosures of which are incorporated herein by reference in their entirety.

[0044] Figure 2 A top view of object 121 is shown, which can be mounted on object holder 101 so that the object, together with object holder 101, can be moved between the processing areas of particle beam columns 3, 7 and the processing area of ​​laser scanner 15 using transport device 103. A sample 123 to be inspected, and which may be, for example, a packaged integrated circuit or a potted integrated circuit, is mounted on object 121. Sample 123 is mounted on sample holder 125, which is mounted on mounting plate 127 of object 121. Figure 2 The cross 129 in the diagram represents a mark produced on the sample 123 by the laser beam 17 of the laser scanner 15. By scanning the mark 129 with the electron beam 5, the mark 129 can be captured in the electron microscope image generated in the process, and the position of the mark 129 in the coordinate system of the electron beam column 3 can also be determined, for example, based on such an electron microscope image.

[0045] Three additional sample holders 131 are mounted on the mounting plate 127 of the object 121, each sample holder providing a partial mark 133 to collectively form a mark that determines its position and orientation. Each partial mark 133 has a disk geometry and can be detected by scanning with particle beams 5 and 9 and also by scanning with laser beam 17. The disk is defined by a hole in a baffle plate. The circular hole can be identified in the resulting electron microscope image by scanning with an electron beam, for example, an electron beam column, and the position of the baffle and thus the partial mark in the coordinate system of the electron beam column 3 can also be determined. Light passing through the circular hole in the baffle plate is redirected to a photodetector 151 (see...). Figure 1 Once the laser beam 17 scanning the corresponding part marked 133 overlaps with the opening in the shield, the photodetector emits a signal. In their respective cases, the photodetector ( Figure 2(Not shown) Arranged below each circular hole in the baffle. The position of the baffle or partial mark 133 in the coordinate system of the laser scanner 15 can be determined by evaluating the signal provided by the photodetector, which depends on the scanning position of the laser beam 17. Details regarding marks that can be detected by both the laser scanner 15 and the particle beam columns 3, 7 can be found in the aforementioned US2011 / 0198326 A1. Other embodiments of such marks are possible. For example, a layer already deposited on the surface of an object and made of a reflective material (e.g., a layer of gold deposited in an area having the shape of the letter "L") can be used as such a second mark, wherein the laser scanner includes a photodetector that detects light when the laser beam is directed to the reflective layer.

[0046] The following will refer to Figure 3 The flowchart shown illustrates a material processing method according to a first embodiment, which can be performed using a material processing system 1. The method includes multiple steps, wherein a sample 123 is arranged in the processing regions of an electron beam column 3 and an ion beam column 7. These steps are described in... Figure 3 The image is shown within rectangle 201. The method further includes several steps, wherein the sample 123 is arranged in the processing area 13 of the laser scanner 5. These steps are described in... Figure 3 is shown within rectangle 203.

[0047] Assuming sample 123 is a packaged integrated circuit containing electronic circuit elements such as transistors, the aim is to generate an electron microscopy image of these electronic circuit elements. Therefore, these circuit elements form a region of interest within the packaged integrated circuit. The position of the region of interest relative to the outer surface of the integrated circuit is determined from a CAD model of the integrated circuit. The method begins by attaching sample 123 to sample holder 125, and mounting sample holder 125 onto mounting plate 127 of object 121. Similarly, sample holder 131, bearing partial markings 133, is mounted onto mounting plate 127.

[0048] Next, object 121 is mounted on object holder 101, and the transport system places the object in the processing area of ​​electron beam column 3. Subsequently, in step 205, the three partial marks 133 that together form the first mark are scanned, which can also be scanned by laser beam 17. Because the three partial marks 133 are arranged on sample holder 131 with a large distance between them, all three partial marks 133 cannot enter the scanning area 11 of electron beam column 3 simultaneously. Therefore, after scanning one of the partial marks 133, the actuation positioning device 111 is activated to bring the corresponding next partial mark 133 into the scanning area 11 of electron beam column 3. After scanning the three partial marks 133 and determining their positions in the coordinate system of electron beam column 3, the position and orientation of the first mark formed by the three partial marks 133 in the coordinate system of electron beam column 3 can also be determined.

[0049] Next, in step 207, after the target region on sample 123 has been moved into the scanning area 11 of electron beam column 3 by actuation positioning device 111, the target region is scanned with electron beam 5. The target region is a portion of the surface of sample 123, and the region of interest is arranged below this portion. In step 209, the position where the second mark 129 will be placed within the target region is determined using a CAD model of sample 123. This position can be determined either in the coordinate system of electron beam column 3 or in the coordinate system of object 121 (i.e., the position relative to the portion of mark 133 that forms the first mark). Since the target region is scanned with an electron beam, this position relative to the target region is also given and known.

[0050] Subsequently, the object 121 is moved to the processing area 13 of the laser scanner 15 via a transport system. In step 211, a first mark formed by partial marking 133 is scanned with a laser beam 17, and the position and orientation of the first mark in the coordinate system of the laser scanner 15 are determined. Next, in step 213, a second mark 129 is generated at the location in the target area determined in step 209. The second mark 129 may have, for example, a cross shape, and this mark can be generated by scanning the cross shape with a laser beam, since material has been removed from the sample along the path traversed by the laser beam.

[0051] Next, object 121 is transported back to the processing area of ​​particle beam columns 3 and 7, specifically, such that the target area is positioned within the scanning area of ​​electron beam column 3. Then, in step 216, the target area is scanned, wherein the second mark 129 generated by the laser beam is also scanned. For example, an electron microscope image of the target area can be generated based on electrons detected during the scan, wherein the image also includes an image of the second mark 219. Next, the position of the second mark 219 relative to the target area is determined, and this position is compared with the position relative to the target area determined in step 209. In step 219, a correction for the processing performed with laser beam 17 is determined based on the difference between these two positions.

[0052] Subsequently, object 121 is transported back to processing area 13 of laser scanner 15, and in step 221, the portion of mark 133 forming the first mark is scanned again with laser beam 17 to determine the position of the first mark in the coordinate system of laser scanner 15. Then, laser beam 17 is operated to remove material from sample 123 until a position immediately adjacent to the region of interest. Here, laser beam 17 is controlled based on the CAD model of the sample, wherein the correction determined in step 219 is used to compensate for the deviation between the perceived position where the laser beam is guided and the actual incident position of the laser beam in each case.

[0053] The volume of material to be removed is determined based on the CAD model of the sample, such that a material layer is left between the surface of the remaining material and the region of interest as a protective measure. The thickness of the material layer is selected such that even if too much material is removed due to anticipated errors in controlling material removal, no material will be removed from the region of interest. Due to the correction determined in step 219, the thickness of the material layer can be chosen to be relatively small.

[0054] Subsequently, object 121 is transported back to the processing area of ​​particle beam columns 3 and 7. In step 225, the first mark formed by partial marker 133 is scanned again with electron beam 5. Then, in step 227, the material layer retained in front of the region of interest in step 223 is removed with ion beam 9. Because the material layer to be removed with ion beam 9 has only a very small thickness due to the correction determined in step 219, this material removal can be performed with ion beam 9 in a relatively short amount of time.

[0055] Next, in step 229, the desired region of interest is scanned with electron beam 5 to generate an electron microscope image of the region of interest. In step 231, the image can be stored in a storage medium.

[0056] refer to Figure 4 The second embodiment of this method will now be described. This method is generally similar to the one described in the reference document. Figure 3 The method of the first embodiment is described below. Essentially, the method of the second embodiment will be described below, differing from the method of the first embodiment in its method steps. Similar steps between the two methods will not be described again to avoid repetition and will be indicated by the same reference numerals. To understand these steps, reference should be made to the section on... Figure 3 The first embodiment is described.

[0057] The main difference between the method of the second embodiment and the method of the first embodiment is that, before steps 211 and 213 for generating the second mark in the target area using a laser beam, the object 121 is not brought into the processing area of ​​the electron microscope to scan the baffle and the target area with the electron microscope (steps 205 and 207 of the first embodiment). Instead, the object 121 is immediately brought into the processing area of ​​the laser scanner. It is assumed here that the position of the target area relative to the first mark 133 (i.e., the baffle) is known precisely enough to determine the position of the second mark in the target area relative to the baffle in step 209. Therefore, in step 211, the mark 133 is then scanned with a laser beam to reference the coordinate system of the object 121 relative to the coordinate system of the laser scanner. Next, in step 213, the mark is placed on the object 121 at the position determined in step 209 using a laser beam.

[0058] Subsequently, object 121 is transported to the processing area of ​​particle beam columns 3 and 7, and in step 215, partial marker 133 is scanned to determine the position and orientation of the first marker in the coordinate system of electron beam column 3. Next, the target area on sample 123 is scanned with electron beam 5 to detect the second marker 129. Then, the position of the second marker 129 relative to the first marker is determined, and this position is compared with the position determined in step 209. In step 219, a correction for the processing performed with laser beam 117 is determined based on the difference between these two positions, after which the method continues as in the first embodiment.

[0059] In the methods of the first and second embodiments, after the correction is determined in step 219, the position of another second mark in the target area can be determined according to step 209, and such a second mark can be generated in the target area with a laser beam, taking the correction into account. Then, in a step corresponding to step 216 or 217, this additional second correction is scanned with an electron microscope to obtain an improved correction in a step corresponding to step 209. Then, in a step corresponding to step 223, during material removal with a laser beam, the improved correction is subsequently used to control the laser beam to further improve the accuracy of material removal. This process can be repeated further to iteratively improve the correction.

Claims

1. A material processing method performed by a material processing system, in, The material processing system includes: At least one particle beam column, the at least one particle beam column being configured to guide at least one particle beam into a first processing region, and A laser scanner configured to guide a laser beam to a second processing area, wherein the material processing method includes: The first mark placed on the object is scanned with at least one particle beam; The first mark is scanned with the laser beam, and a second mark is generated on the object using the laser beam. The second mark is scanned with the at least one particle beam; and Based on scanning the second mark with the at least one particle beam, scanning the first mark a second time with the laser beam, and removing the material of the object with the laser beam.

2. The material processing method according to claim 1, wherein, The first scan of the first mark with the laser beam includes determining the position of the first mark in the coordinate system of the laser scanner.

3. The material processing method according to claim 1 or 2, wherein, Generating the second mark includes: fixing a position in the coordinate system of the laser scanner based on scanning the first mark with the laser beam, and The laser beam is guided to the position determined in the coordinate system of the laser scanner.

4. The material processing method according to claim 3, wherein, Fixing the position in the coordinate system of the laser scanner is also based on a model of the geometry of at least a portion of the object.

5. The material processing method according to claim 1 or 2, wherein, The first scan of the first marker with the at least one particle beam includes determining the position of the first marker in the coordinate system of the at least one particle beam column.

6. The material processing method according to claim 1 or 2, wherein, Scanning the second marker with the at least one particle beam includes determining the position of the second marker in the coordinate system of the at least one particle beam column.

7. The material processing method according to claim 1 or 2, further comprising: The position of the second mark relative to the first mark is determined by scanning the first mark with the at least one particle beam and scanning the second mark with the at least one particle beam.

8. The material processing method according to claim 1 or 2, further comprising: In the coordinate system of the laser scanner, a position is fixed relative to the position of the first mark, which is determined based on the first scan of the first mark with the laser beam; The laser beam is directed to that location to generate the second mark; The position of the second mark relative to the first mark is determined based on a first scan of the first mark with the at least one particle beam and a second mark scanned with the at least one particle beam; The material of the object is removed by the laser beam based on the difference between the position of the second mark relative to the first mark and the position fixed for generating the second mark with the laser beam.

9. The material processing method according to claim 1 or 2, further comprising: Before the first mark is scanned with the laser beam for the first time and before the second mark is generated, the first mark is scanned a second time with the at least one particle beam, and at least a portion of the object is scanned with the at least one particle beam; A position is fixed relative to the position of the first mark by scanning the portion of the object with the at least one particle beam, the position of the first mark being determined by a second scan of the first mark with the at least one particle beam; Based on scanning the first mark with the laser beam and fixing a position in the coordinate system of the laser scanner based on the fixed position; and The laser beam is guided to the fixed position to produce the second mark.

10. The material processing method according to claim 1 or 2, further comprising: After the material of the object is removed with the laser beam, the material of the object is removed with the at least one particle beam.

11. The material processing method according to claim 10, wherein, The particle beam used during the removal of material from the object using the at least one particle beam is an ion beam.

12. The material processing method according to claim 1 or 2, further comprising: After the material of the object is removed with the laser beam, at least a portion of the object is scanned with the at least one particle beam; as well as The detection is based on the signal generated by scanning the object.

13. The material processing method according to claim 12, wherein, The particle beam used during the scanning of at least a portion of the object with the at least one particle beam is an electron beam.

14. The material processing method of claim 12, further comprising generating an image based on the detected signal; and Use a display medium to present the generated image and / or store the generated image in a storage medium.

15. The material processing method according to claim 1 or 2, wherein, The object includes a sample holder and a sample to be inspected held in the sample holder.

16. The material processing method according to claim 15, wherein, The first mark is separated from the sample and held in place by the sample holder.

17. The material processing method according to claim 1 or 2, wherein, The first marker includes at least one or more holes and at least one light detector.

18. The material processing method according to claim 1 or 2, wherein, The processing system also includes a conveying system configured to convey the object from the first processing area to the second processing area and from the second processing area to the first processing area.

19. The material processing method according to claim 18, wherein, The transport system is configured to move the object relative to the particle beam column, and the method includes: Before the first marker is scanned with the at least one particle beam, the object is moved relative to the particle beam column in such a manner that the first marker is positioned within the scanning area of ​​the particle beam column; and Before scanning the second mark with the at least one particle beam, the object is moved relative to the particle beam column in such a way that the second mark is arranged in the scanning area of ​​the particle beam column.

20. A material processing system, comprising: At least one particle beam column, the at least one particle beam column being configured to guide at least one particle beam into a first processing region, and A laser scanner configured to direct a laser beam to a second processing area, wherein the material processing system is configured to perform a material processing method according to any one of claims 1 to 19.

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