Apparatus and method for manipulating microscopic samples

Abstract

A sample handling system for a sample to be used in a charged particle beam process. The sample handling system includes: a carrier defining a passageway; a wire slidably supported by the carrier and at least partially received; and a feed mechanism. The wire is configured to slide through the passageway. The wire includes a supported portion and a protruding portion. The supported portion is disposed in the passageway, and the protruding portion extends from the carrier for engaging the sample. The feed mechanism is configured to drive the wire through the pathway to control a length of the protruding portion.

Description

Technical Field

[0001] The present disclosure relates to a sample manipulation system, and more particularly to a sample manipulation system in a charged particle microscope. Summary of the invention

[0002] In one aspect, the present disclosure provides a sample manipulation system for a sample to be used in a charged particle beam process. The sample manipulation system includes: a carrier that defines a passage; a wire that is slidably supported and at least partially contained by the carrier; and a feed mechanism. The wire is configured to slide through the passage. The wire includes a supported portion and a protruding portion. The supported portion is disposed in the passage, and the protruding portion extends from the carrier for engaging the sample. The feed mechanism is configured to drive the wire through the passage to control the length of the protruding portion.

[0003] In another aspect, the present disclosure provides a method for manipulating a sample using the sample manipulation system. The method includes: acquiring an image; driving the wire through the passage to a predetermined length of the protruding portion of the wire via a first actuator of the sample manipulation system; and adjusting the distance between the distal end of the wire and the sample via a second actuator coupled to the sample manipulation system.

[0004] In another aspect, the present disclosure provides a charged particle microscope. The microscope includes a sample holder for holding a sample; a sample manipulation system, the sample manipulation system including: a carrier defining a passage; a wire that is slidably supported and at least partially contained by the carrier, the wire including a supported portion and a protruding portion, wherein the supported portion is disposed in the passage and the protruding portion extends from the carrier for engaging the sample; and a feed mechanism, the feed mechanism including a first actuator for driving the wire along the passage; a second actuator, the second actuator being coupled to the sample manipulation system; at least a detector; and a controller, the controller including a processor and a non-volatile memory for storing computer-readable instructions, by executing the instructions in the processor, the charged particle microscope is configured to: acquire an image via the detector; adjust the length of the protruding portion of the wire from the carrier via the first actuator based on the acquired image; and adjust the relative position between the sample and the distal end of the wire via the second actuator.

[0005] Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of the steps of the peeling process.

[0007] Figure 2 is a schematic diagram of another step of the stripping process.

[0008] Figure 3 is a schematic diagram of another step of the stripping process.

[0009] Figure 4 is a schematic diagram of the sample manipulation system.

[0010] Figure 5 is a schematic diagram of another embodiment of a sample manipulation system.

[0011] Figure 6 is a schematic diagram of yet another embodiment of a sample manipulation system.

[0012] Figure 7 is a schematic diagram of a dual-beam charged particle microscope (CPM) system including a sample manipulation system.

[0013] Figure 8 is a flow chart depicting a method of manipulating a sample using a sample manipulation system. DETAILED DESCRIPTION

[0014] In order to prepare samples for charged particle beam processes (such as detection by transmission electron microscopy (TEM), scanning electron microscopy (SEM), etc.), the samples have been ground into thin slices. Some techniques for preparing TEM samples may involve cleavage, chemical polishing, mechanical polishing, or wide beam low energy ion milling. Combinations of these techniques are also possible. These techniques generally require the starting material to be cut into smaller and smaller fragments, thereby destroying most of the original sample. Other techniques, commonly referred to as "peeling" procedures, use a focused ion beam (FIB) to cut samples from a substrate while greatly limiting or eliminating damage to the surrounding areas of the substrate. For example, these techniques are useful for analyzing the results of semiconductor manufacturing.

[0015] The distal end of the wire (or needle) can be attached to the sample (such as a sample after grinding) for removing the sample from the bulk material. The sample can be held by the wire for further processing or transfer to be detected by another tool (such as TEM). The transmission to the TEM grid can occur without removing the sample from the grinding chamber. The sample can be attached to the TEM grid, and the wire can be cut off subsequently so that the sample remains with the TEM grid. A small portion of the wire can also remain with the sample. Since the wire is cut, the small portion of the wire is lost, thereby reducing the length of the remaining wire. This process can be referred to as a "stripping" process. Other details of the stripping process are described in U.S. Patent No. 7,005,636, the entire contents of which are incorporated herein by reference.

[0016] Automating the process of lamella handling (e.g., peeling lamellae from a wafer and transferring them to a TEM grid) to scale up production encounters many difficulties, such as the need to replace wires due to wire loss. Replacing wires is a time-consuming process that requires venting the chamber and then restoring operating conditions after wire replacement. Moreover, after severing the wire attached to the sample, it may be necessary to reduce the diameter of the wire, such as by milling with a focused ion beam before performing another peel, which is also time-consuming.

[0017] For consistency across multiple strippings, and to reduce or eliminate grinding time, the width / diameter of the wire is preferably constant or nearly constant. In addition, the sample manipulation system is preferably able to provide a sufficiently long wire to accommodate many strippings (e.g., thousands or tens of thousands of strippings) before replacement is required. This can greatly reduce or eliminate the number of times the wire must be replaced. The present disclosure provides a sample manipulation system and method for advancing the wire when the wire is worn, thereby reducing or eliminating the need for frequent needle replacement.

[0018] Disclosed herein is a sample manipulation system and method for manipulating microscopic samples. The sample manipulation system includes a wire, a carrier and a feed mechanism. The carrier defines a passage through which the wire can slide. At least a portion of the wire in the passage is supported by the carrier or the passage formed by the carrier. The passage may be straight and may have different cross-sectional areas along the length of the passage. The wire in the passage may be substantially straight. The portion of the passage supporting the wire may have the minimum cross-sectional area of ​​the entire passage so as to limit the lateral movement of the wire in the passage. A distal end of the wire protruding outside the carrier may be attached to the sample and support the sample during the stripping process. The feed mechanism may be configured to drive the wire along the passage to control the length of the wire protruding from the carrier. In some examples, some or all of the passages in the passage may be curved.

[0019] In one example, the wire has a uniform width or diameter. The cross section of the wire may be circular, square or any other suitable cross section. The width of the wire (which may also be referred to as the diameter of the wire in this article, for example, when the wire has a circular cross section) may be 10 microns or less. In other examples, the width may be 5 microns or less. In other examples, the width may be 2 microns or less. In other examples, the width may be 50 microns or less. In other examples, a part of the wire (for example, relative to the distal end protruding from the carrier) may be wrapped around a reel. If the width or diameter of the wire is less than 5 microns, such as 2 microns, the step of FIB thinning of the wire tip may be skipped.

[0020] The carrier may at least partially contain and support at least a portion of the wire. The carrier may be tubular, channeled, a combination thereof, or any suitable shape for receiving, supporting and at least partially containing the wire. Tubular may include a cylindrical or any shaped cross-section of a tube. Channeled may include grooves for forming the passageway for receiving the wire and may have any shaped cross-section. The passageway defined by the carrier may have any suitable shaped cross-section.

[0021] The feeding mechanism drives the wire rod along the length of the passage and controls the length of the protruding portion of the wire rod. For example, the feeding mechanism can drive the wire rod in the feeding direction to increase the length of the protruding portion. The feeding mechanism may include an actuator (which may also be referred to as the first actuator in this article), which is used to drive the wire rod along the passage. The wire rod may be operably coupled to the actuator. The actuator may use any suitable member to drive the wire rod. For example, the actuator may be a piezoelectric actuator or a motor or any other suitable electric drive device.

[0022] The actuator may be coupled to the wire via a clamping mechanism or a pinch roller. In one example, the clamping mechanism may be positioned at the end of the passage opposite to the end of the protruding wire to drive the wire along the passage. The clamping mechanism may be fixed at the location of the wire and move with the wire when the wire moves along the passage. The clamping mechanism may be partially or completely enclosed in the carrier. That is, at least a portion of the clamping mechanism is within the passage.

[0023] In another example, the actuator can be coupled to the wire by a plurality of rollers, such as a pinch roller. The roller can be positioned at any position along the path. In one example, the roller can engage with the wire at the end of the carrier opposite to the protruding wire. In another example, the roller can engage with the wire through an opening on the carrier. In yet another example, the roller can be enclosed in the carrier. The wire can be arranged between the plurality of rollers so that the roller sandwiches the wire and drives the wire in the feed direction. The roller can clamp and drive the wire directly or indirectly.

[0024] In yet another example, the actuator may be coupled to the wire via a reel. The end of the wire opposite the end protruding from the carrier may be wound on a reel positioned within the shield. The actuator may rotate the reel to move the wire along the pathway.

[0025] The sample manipulation system can be incorporated in a charged particle microscope for sample processing. The sample manipulation system can be coupled to one or more second actuators for adjusting the relative position of the distal end of the wire and the sample. The second actuator can translate and rotate the sample attached to the wire. The second actuator can be a precision manipulator that provides at least four degrees of freedom (i.e., X translation, Y translation, Z translation, and rotation) for moving and positioning the sample in three-dimensional space.

[0026] In one example, the charged particle microscope system may include a first detector for detecting the length of the protruding portion of the wire. The actuator of the feed mechanism may be actuated based on the detected length of the protruding portion. The first detector may be an optical detector or a charged particle detector. The first detector may acquire an image including a portion of the carrier. The feed mechanism may be configured to drive the wire to a predetermined feed length in response to the detected length of the protruding portion. The charged particle microscope system may also include a second detector for detecting the relative position of the distal end of the wire and the sample. The second detector may acquire an image including the sample and the distal end of the wire. The second actuator may be actuated based on the detected relative position. In one example, the first detector and the second detector are the same detector, such as an electronic detector for acquiring a SEM image.

[0027] Before explaining any embodiments of the present disclosure in detail, it should be understood that the present disclosure is not limited in its application to the details of construction and arrangement of components set forth in the following description or shown in the following drawings. The present disclosure is capable of other embodiments and can be practiced or carried out in various ways.

[0028] The present disclosure relates to a sample manipulation system 10 (which may be referred to simply as a manipulation system 10), mainly in Figures 4 to 6 1 is shown for a sample 14 to be analyzed or processed by a charged particle beam (e.g., a transmission electron microscope TEM as an example). The application shown is only one example, and the manipulation system 10 can be used in any sample manipulation application. The sample manipulation process may also be referred to as a "peeling" process, and includes: picking up the sample 14 ( Figure 1 ); attaching the sample 14 to another object (which may be referred to herein as a holder) such as a TEM grid 22 ( Figure 2 ); and cutting wire 18 ( Figure 3 ).

[0029] Figures 1 to 3 An exemplary stripping process is shown, and Figure 4 A sample manipulation system 10 is shown, wherein Figure 5 and Figure 6Depicted is an alternative sample manipulation system. Figures 1 to 4 The manipulation system 10 may be configured to remove the sample 14 from the wafer 30 ( Figure 1 ) and then carry the sample 14 and transport the sample 14 to the TEM grid 22 ( Figure 2 ) for analysis by TEM. Figure 4 ) includes a carrier 38, a wire 18 and a feeding mechanism 54.

[0030] In the illustrated embodiment, particular reference is made to Figure 4 , the carrier 38 is configured to at least partially support the wire 18. The carrier 38 includes at least a solid body for at least partially supporting the wire 18, but may include other structures. Any configuration of the carrier 38 for supporting the wire 18 is possible. As an example, the carrier 38 has a first carrier end 58 and a second carrier end 62 and defines a passage 66, through which the wire 18 can be arranged. The passage 66 defines a hole 86, through which the wire 18 can be fed. In the example shown, the carrier 38 can be formed as a hollow cylinder. The carrier 38 can be tubular, channeled, a combination thereof, or any suitable shape for receiving, supporting and at least partially accommodating the wire 18. The tubular may include a cylindrical or a tube with a cross section of any shape. The channeled may include a groove for forming the passage for receiving the wire 18, and may have a cross section of any shape.

[0031] The carrier 38 includes a distal end 83 from which the wire 18 protrudes. As an example, the carrier 38 can be made of a polymer. As another example, the carrier 38 can be made of a metal, a ceramic, a polymer, or any combination thereof.

[0032] In the illustrated embodiment, the wire 18 has a uniform width W ( Figure 4 ). The width W of the wire 18 may be 5 microns or less. As an example, the width W is 5 microns. As another example, the width W is 2.5 microns. In other embodiments, the width W may be 50 microns or less. The wire 18 may have any suitable wire length. In one example, the wire 18 has a wire length 140 of at least 10 mm. In some embodiments, the wire length 140 may be longer than 50 mm. In the illustrated embodiment, the wire 18 may be substantially straight. In other embodiments, the wire 18 may be curved, bent, wound, or any combination thereof, particularly at the first carrier end 58.

[0033] Continue to refer Figure 4, the wire 18 is slidably supported and at least partially contained by the carrier 38. The wire 18 can be characterized as a flexible strand (e.g., the wire is easily manipulated or can be extended) or a rigid strand. In embodiments where the wire 18 is a flexible strand, the wire 18 can be provided as a generally straight length of wire or wound around a reel 108 (e.g., Figure 6 , which will be described in more detail below). The wire 18 may be partially or completely made of a metal such as tungsten or any other suitable metal or combination of metals. In some embodiments, the material may additionally or alternatively include plastic, polymer, glass, ceramic, synthetic fiber or other material. The wire 18 may be configured to slide through the passage 66 in a feed direction 106. The feed direction 106 (i.e., the Z direction or Z axis) may be away from the carrier 38, so that the length of the protruding portion 26 of the wire 18 (from the distal end 82 of the wire 18 to the distal end 83 of the carrier 38) increases. Further, the feed direction 106 may be toward the sample 14.

[0034] The wire 18 includes a supported portion 110 and a protruding portion 26. The supported portion 110 may be disposed within the passage 66. The supported portion 110 may be at least partially supported by the carrier 38. The protruding portion 26 of the wire 18 extends from the carrier 38 and passes through the hole 86. The protruding portion 26 may be understood as any portion of the wire 18 that extends from the carrier 38 in the feed direction 106 (e.g., not contained within the carrier 38). The protruding portion 26 may be configured to engage the sample 14. The protruding portion 26 may further be configured to support the sample 14 when attached to the sample.

[0035] like Figure 4 As shown, the feeding mechanism 54 is configured to move the wire 18 relative to the carrier 38, such as to slide the wire 18 through the passage 66. The feeding mechanism 54 includes at least an actuator 126 (which may be referred to as a first actuator in this article), which is used to move the wire 18 relative to the carrier 38. In the illustrated embodiment, an actuator 126 may be adopted. In other embodiments, a combination of one or more actuators 126 may be adopted. The actuator 126 may be a piezoelectric actuator, a motor, any type of linear actuator or any other suitable actuator or motor type. The actuator 126 may be electric. In response to being activated, the actuator 126 drives the wire 18 drive length, which may be any desired length. As an example, the drive length may be 15 microns. As another example, the drive length may be any length in the range of 1 micron to 20 microns.

[0036] Thus, the feed mechanism 54 can be configured to drive the wire 18 through the passage 66 in a feed direction 106 (e.g., parallel to or along the Z-axis 106 in the illustrated orientation). A portion of the feed mechanism 54 can be housed within the carrier 38, or the feed mechanism 54 can be disposed entirely within the carrier 38. Alternatively, the feed mechanism 54 can be located proximate to the carrier 38. Any location is contemplated depending on the application.

[0037] The other components of the feed mechanism 54 may take any suitable form, such as for gripping and / or guiding the wire 18 during movement driven by the actuator 126 .

[0038] As an example, Figure 4 The feeding mechanism 54 is shown to include a clamp 56, which is configured to apply a clamping force to the wire 18 so that the wire 18 is firmly clamped. The actuator 126 may be configured to move the clamp 56 linearly, for example, in the Z direction 106, to move the wire 18 accordingly. The clamp 56 may be in direct contact with the wire 18 at one or more locations of the wire 18. The clamp 56 may include two or more jaws 57, which are pushed toward each other and are configured to apply a clamping force on the wire 18, and in other examples, any other suitable configuration may be provided for coupling the wire 18 to the actuator 126. For example, the clamp 56 is in direct contact with the wire 18 in the circumferential direction. When the wire 18 travels along the passage 66, the clamp 56 may travel with the wire 18.

[0039] The passage 66 may have different cross-sectional areas along its length (Z axis). The cross-sectional area on the first carrier end 58 may be larger than the second carrier end 62 to accommodate the clamping mechanism (eg, clamp 56) when the wire 18 is driven in the feed direction 106.

[0040] In another example, in Figure 5 As shown in , the feeding mechanism 54 may include a plurality of pinch rollers 144 . Figure 5 An example use of Figure 4 Many of the components in the examples are identical, and only the differences are described herein. Similar components are used with Figure 4126 to mark, and this article refers to their description, and there is no need to repeat.Pinch roller 144 can be driven by actuator 126, so that the activation of actuator 126 rotates pinch roller 144.Therefore, pinch roller 144 can drive wire 18 in response to the activation of actuator 126.One, some or all pinch rollers 144 can be actively driven, and any remaining pinch rollers can be passively driven.Pinch roller 144 can clamp wire 18.Wire 18 can be sandwiched between pinch rollers 144, so that pinch roller 144 directly engages wire 18, applies clamping force thereto, and drives wire 18 during the rotation of pinch roller 144.As another example, pinch roller 144 can be pressed around sleeve (not shown) on wire 18 (because wire 18 itself can be very thin). Such a sleeve (not shown) may be embodied similarly to clamp 56, and movement of pinch roller 144 feeds the sleeve (not shown) and thereby also feeds wire 18. In some examples, passage 66 may have a constant cross-section along its length.

[0041] In yet another example, Figure 6 , the wire 18 can be driven by an actuator 126 connected to the reel 108. The end of the wire 18 opposite the distal end 82 is wound on the reel 108. The reel 108 is enclosed in a shield 109, wherein the wire 18 extends through the shield 109. By rotating the reel 108 with the actuator 126, the wire 18 moves along the passage 66.

[0042] Figure 7 1 is a highly schematic depiction of an embodiment of a dual beam charged particle microscope (CPM) system (such as microscope 1) in which a sample manipulation system 10 may be implemented; more specifically, it shows an embodiment of a FIB-SEM. Microscope 1 includes an electron optical column 10000 that produces a charged particle beam 3 (in this case an electron beam) propagating along an electron optical axis 1010. The electron optical axis 1010 may be aligned with the Y axis 102 of the system. Column 10000 is mounted on a vacuum chamber 5, which includes a sample holder 7 and an associated actuator 8 for holding / positioning a wafer 30 / sample 14. Wire 18 may be finely moved in space by a precision manipulator 146 (which may also be referred to herein as a second actuator), which in turn manipulates sample 14. The vacuum chamber 5 is evacuated using a vacuum pump (not shown). Also shown is a vacuum port 9, which may be opened to introduce an object (component, sample) into or remove it from the interior of the vacuum chamber 5. If desired, the microscope 1 may include a plurality of such ports 9 .

[0043] The column 10000 comprises an electron source 1000 and an illuminator 2. This illuminator 2 comprises lenses 1100 and 1300 for focusing the electron beam 3 onto the sample 14, and a deflection unit 1500 (for performing beam steering / scanning of the beam 3). The microscope 1 further comprises a controller 130 for controlling, among other things, the deflection unit 1500, the lenses 1100, 1300, the wire 18, the detectors 1900, 2100, and a display unit 2700 for displaying the information collected from the detectors 1900, 2100.

[0044] In addition to the electron column 10000 described above, the microscope 1 also includes an ion optical column 3100. This includes an ion source 3900 and an illuminator 3200, and these generate / guide an ion beam 3300 along an ion optical axis 3400. In order to facilitate easy access to the sample, the ion axis 3400 is tilted relative to the electron axis 1010. As described above, such an ion (FIB) column 3100 can be used, for example, to perform processing / machining operations on the sample 14, such as cutting, milling, etching, deposition, etc. The ion column 3100 can be used to produce an image of the sample 14. It should be noted that the ion column 3100 is capable of generating a variety of different types of ions at will; therefore, reference to the ion beam 3300 does not have to be regarded as specifying a specific type in the beam at any given time - in other words, the beam 3300 may include ion species A for operation A (such as milling) and ion species B for operation B (such as implantation), where species A and B can be selected from a variety of possible options. The ion source 3900 may be a liquid metal ion source or a plasma ion source.

[0045] Also illustrated is a gas injection system (GIS) 4300 that can be used to perform localized injection of gases such as etching or precursor gases for the purpose of performing gas-assisted etching or deposition. For example, such gases can be stored / cached in a reservoir 4100 and can be applied through a narrow nozzle 4200 so as to be ejected near the intersection of axes 1010 and 3400.

[0046] Detectors 1900, 2100 are selected from a variety of possible detector types that can be used to detect different types of "stimulated" radiation emitted from sample 14 in response to irradiation by (impact) beam 3 and / or beam 3300. For example, detector 1900 can be an X-ray detector, such as a silicon drift detector (SDD) or a silicon lithium (Si(Li)) detector. For example, detector 2100 may include an electron detector in the form of a solid-state photomultiplier tube (SSPM) or a vacuum photomultiplier tube (PMT). This can be used to detect backscattered and / or secondary electrons emitted from the sample. The skilled person will understand that many different types of detectors can be selected in a setup such as that depicted, including, for example, annular / segmented detectors. By scanning beam 3 or beam 3300 over sample 14, stimulated radiation including, for example, X-rays, infrared / visible / ultraviolet light, secondary ions, secondary electrons (SE) and / or backscattered electrons (BSE) is emitted from the sample. Since such stimulated radiation is position sensitive (due to the scanning motion), the information obtained from detectors 1900 and 2100 will also be position dependent. Thus, detectors 1900, 2100 may be embodied as charged particle cameras, but in some embodiments, any optical detector may be employed.

[0047] Signals from detectors 1900 and 2100 are transmitted along control line (bus) 2500, processed by controller 130, and displayed on display unit 2700. Such processing may include operations such as combination, integration, subtraction, false coloring, edge enhancement, and other processing known to technicians. In addition, automatic identification processes may be included in such processing. The controller includes a non-transitory memory 170, which is used to store computer-readable instructions; and a processor 166. The method disclosed herein can be implemented by executing computer-readable instructions in the processor. For example, the controller 130 can control the microscope 1 to mill and image the sample 14, collect data, and process the collected data to generate a 3D model of the internal features of the sample 14. The controller 130 can control the microscope 1 to mill the sample 14 mounted on the TEM grid 22, image the milled sample 14, and display the image on the display 2700. The controller 130 can adjust the ion beam energy by adjusting one or more lenses 1100, 1300 and / or the ion source 3900. The controller 130 can adjust the direction of the ion beam relative to the sample 14 by adjusting the sample orientation and / or optical components in the ion column 3100.

[0048] The precision manipulator 146 can be operably coupled to move the sample manipulation system 10 in three-dimensional space. The precision manipulator 146 can provide fine position adjustment, for example, in increments of about tens or hundreds of nanometers. As an example, the fine position adjustment can be made in increments of 100 nm. Thus, the precision manipulator 146 is configured to move the wire 18 to a position of the sample 14 (e.g., Figure 1 ), the sample can then be cut from the wafer 30, and the sample 14 can then be moved to the TEM grid 22 (as shown in FIG. Figure 2 Once the sample 14 has been transferred to the TEM grid 22, the wire 18 is cut (as shown). Figure 3 ). The cut portion 16 of the wire 18 remains attached to the sample 14. The cut portion 16 typically has a cut length 20 ( Figure 3 ), but can have any length depending on the operation.

[0049] Continue to refer Figure 7 , the sample manipulation system 10 may be in operative communication with the detectors 1900, 2100. The sample manipulation system 10 may also be in operative communication with the controller 130. The controller 130 may include a processor 166 (e.g., a microprocessor 166, a microcontroller 130, or another suitable programmable device) and a non-transitory memory 170. The memory 170 may include, for example, a program storage area 174 and a data storage area 178. The program storage area 174 and the data storage area 178 may include a combination of different types of memory 170, such as a read-only memory ("ROM"), a random access memory ("RAM") (e.g., a dynamic RAM ["DRAM"], a synchronous DRAM ["SDRAM"], etc.), an electrically erasable programmable read-only memory ("EEPROM"), a flash memory, a hard disk, an SD card, or other suitable magnetic memory device, an optical memory device, a physical memory device, an electronic memory device, or other data structure. The programming may be encoded or learned, such as by a neural network, or a combination of both. For example, the neural network may be trained to measure the length and / or relative position between components in the field of view of one of the detectors 1900, 2100, or such programming may be encoded.

[0050] The controller 130 may include one or more inputs and outputs to and from various components, as described above with respect to Figure 7Described. Controller 130 may be configured to provide control signals to output and receive data and / or signals (e.g., detector data, user input signals, etc.) from input. The one or more inputs may include, but are not limited to, detectors 1900, 2100, which are configured to monitor the position of one or more of the wire 18, sample 14, and carrier 38 of sample manipulation system 10. The one or more outputs may include, but are not limited to, actuator 126, precision manipulator 146, and may include other components. Therefore, controller 130 may be programmed to control the position and feeding mechanism 54 of wire 18 based on feedback from one or both of detectors 1900, 2100. For example, controller 130 may be programmed to automatically or semi-automatically adjust the length 138 of protruding portion 26 and the distal end 82 of wire 18 in space based on the feedback.

[0051] The detectors 1900, 2100 may be configured to send a signal, such as an image and / or video, to the controller 130. The controller 130 may, for example, be configured with an image recognition system to detect the length 138 of the protruding portion 26.

[0052] In operation, in response to the length 138 being less than the first predetermined length, the controller 130 may activate the actuator 126 to drive the wire 18 through the hole 86. The first predetermined length may be set by the user to indicate that the length 138 is shorter than the value required to perform the stripping. As an example, the first predetermined length may be between 1 micron and 10 microns, such as 5 microns in one example. In other examples, the first predetermined length may be any suitable length. The controller 130 may be configured to drive the wire 18 to the drive length. The controller 130 may be configured to drive the wire 18 until the detector 1900, 2100 detects that a second predetermined length has been reached, wherein the second predetermined length is greater than the first predetermined length. The second predetermined length may be set by the user to indicate that the length 138 is suitable for performing the stripping. As an example, the second predetermined length may be 20 microns. As another example, the second predetermined length may be any length in the range of 10 microns to 20 microns. In other examples, the second predetermined length may have any suitable value. In some examples, the first predetermined length and the second predetermined length are the same, which may enable ultra-fine control of the length 138 .

[0053] Controller 130 may, for example, be configured with the image recognition system to extract data from the detector signal, such as the location of wire 18 relative to sample 14. However, in some embodiments, the location of wire 18 relative to sample 14 may be detected by a detector separate from detectors 1900, 2100.

[0054] In another embodiment, feedback from the detectors 1900, 2100 need not be employed. Instead, the controller 130 may record the number of peeling processes that have occurred and activate the actuator 126 in response to n peeling processes (eg, at least 100 peeling processes).

[0055] Continue to refer Figure 7 , the electronic controller 130 may be configured to automatically or semi-automatically control the actuator 126 and the precision manipulator 146 in response to the detector feedback. Therefore, the controller 130 controls the movement of the wire 18 in response to the detector feedback. More specifically, the electronic controller 130 may be configured to control the position of the distal end 82 of the wire 18 in 3-dimensional space, for example, to move the distal end 82 of the wire 18 to engage with the sample 14 while the sample is still attached to the wafer 30, or to move the sample 14 to the TEM grid 22. Controlling the position may include moving the carrier 38 (which in turn moves the wire 18) in any combination or orientation in the X direction, Y direction, Z direction and / or rotation. The electronic controller 130 may be further configured to control the length 138 of the protruding portion 26. The length 138 may be between 1 micron and 20 microns. The electronic controller 130 may be further configured to activate the actuator 126 (for example, when the length 138 is less than the first predetermined length or when n peeling processes have occurred).

[0056] Figure 8 800 is a flow chart showing a method 800 for sample processing in a charged particle microscope. The method may include any one or more of steps 801 to 808 in any combination, as well as other additional steps and intermediate steps apparent from this disclosure. Some or all of the methods in the method may be performed by the electronic controller 130.

[0057] In step 801 , a sample 14 , such as a thin section, is processed using a charged particle microscope 1 .

[0058] At step 802, one or more first images of the carrier 38 are acquired, and the length of the protruding portion 26 of the wire 18 is determined from the first images. For example, the length 138 of the protruding portion 26 is determined based on the images acquired from the detectors 1900, 2100. Step 802 may include moving at least a portion of the carrier 38 into the field of view of the detectors 1900, 2100 before acquiring the first images.

[0059] At step 803, the controller determines whether the protrusion length is less than a first predetermined length. It should be understood that "less than" can also mean "less than or equal to". If not, go to step 805. If yes, go to step 804. For example, the controller 130 determines whether the length 138 is less than the first predetermined length.

[0060] In step 804, in response to the length 138 being less than the first predetermined length, the controller 130 activates the actuator 126 so that the length 138 of the protruding portion 26 increases. Step 804 may additionally or alternatively include: using feedback to control the protruding length 138, or feeding the wire 18 by a predetermined length. Once the protruding length has increased, the method returns to step 802. Steps 802, 803, and 804 are repeated until the length 138 of the protruding portion 26 is not less than the predetermined length (no at step 803).

[0061] At step 805, a second actuator (such as precision manipulator 146) is controlled to move distal end 82 of wire 18 to sample 14 (see also Figure 1 ). In step 805, one or more second images may be acquired. Step 805 may include using one or both of the detectors 1900, 2100 to detect the location of the sample 14 relative to the distal end 82 of the wire 18. In one example, one or both of the detectors 1900, 2100 detect the location of the sample 14 based on the second image. The second image may include both the sample 14 and the distal end 82 of the wire 18. Then, the wire 18 may be moved to the vicinity of the sample 14 with high precision under the guidance of the second image. In one example, the carrier 38 supports the wire 18 supporting the sample 14.

[0062] At step 806, wire 18 is attached to sample 14, such as by welding. Sample 14 may be attached to wire 18 using any suitable bonding means.

[0063] At step 807, the sample 14 is processed while attached to the wire 18. In one example, the carrier 38 transfers the sample 14 to the TEM grid 22 (see also Figure 2 ). Step 807 may also include attaching the sample 14 to the TEM grid 22. The sample 14 may be attached to the TEM grid 22 by any suitable bonding means or by simply placing the sample 14 onto the TEM grid 22. In another example, the sample 14 is further processed or imaged in the charged particle microscope 1 while being attached to the wire 18.

[0064] In step 808, the wire 18 is cut (see also Figure 3 ), so that the cut portion 16 is separated from the rest of the wire 18. The cut portion 16 of the protruding portion 26 of the wire 18 remains attached to the sample 14. The sample 14 and the wire 18 can be separated in any suitable manner. For example, any suitable separation device (such as one or more blades configured to cut the wire 18, one or more clamps configured to stretch and break the wire 18, etc.) can be used to cut the wire 18. After cutting the wire 18, the microscope 1 can be used for another peeling process, and thus returns to step 801.

[0065] Other methods of manipulating the sample 14 with the carrier 38 are possible.

[0066] Therefore, method 800 generally includes determining whether the protrusion length is less than the predetermined length, and, if necessary, increasing the protrusion length by activating actuator 126 to provide a sufficient length of wire 18 to attach to sample 14. Feedback (e.g., image data) from one or more detectors can be used to determine the protrusion length. The method generally also includes using feedback (e.g., image data) from one or more detectors in the detector to control precision manipulator 146 to move wire 18 to sample 14. Method 800 generally also includes: using carrier 38 (also through precision manipulator 146) to transfer sample 14 to TEM grid 22, connecting sample 14 to TEM grid 22, and cutting wire 18. Some steps in steps 801 to 808 can be performed in other suitable orders. Additional method steps in subsequent or intermediate steps in method 800 can be obvious from the above disclosure.

[0067] The feed mechanism 54 of the sample manipulation system 10 provides advantages. If a needle is used (as is typical in stripping processes), the needle will likely require a sharpening process to reduce the size (such as width / diameter) of the needle tip. Needle sharpening may take hours. The wire 18 used in the present feed mechanism 54 has a constant diameter so that the sharpening time can be reduced or eliminated. In addition, the number of strippings that can occur before replacing the wire 18 is increased by the sample manipulation system 10 of the present disclosure. The uniform width / diameter of the wire 18 further improves automation repeatability and increases the yield of the stripping process.

[0068] Thus, the present disclosure provides a sample manipulation system 10 and method 800 of feeding a wire 18. Various features and advantages of the present disclosure are set forth in the following claims.

Claims

1. A sample manipulation system for a sample to be used in a charged particle beam process, the sample manipulation system comprising: a carrier, the carrier defining a passage; a wire slidably supported and at least partially contained by the carrier, the wire being configured to slide through the passage, the wire comprising a supported portion and a protruding portion, wherein the supported portion is disposed in the passage and the protruding portion extends from the carrier for engaging the sample; and A feeding mechanism is configured to drive the wire through the passage to control the length of the protruding portion.

2. A sample manipulation system according to claim 1, wherein the width of the wire is 10 microns or less.

3. A sample manipulation system according to claim 1, wherein the wire is made of tungsten.

4. A sample manipulation system according to claim 1, wherein the length of the protrusion is between 1 micron and 20 microns.

5. A sample manipulation system according to claim 1, wherein the feeding mechanism includes an actuator for driving the wire through the passage.

6. A sample manipulation system according to claim 5, wherein the actuator comprises a motor or a piezoelectric actuator.

7. A sample manipulation system according to claim 5, wherein the feeding mechanism further includes a clamping mechanism or a pinch roller, and wherein the actuator is operatively connected to one or both of the clamping mechanism or the pinch roller to drive the wire.

8. A method for manipulating a sample using the sample manipulation system according to claim 1, the method comprising: Get the image; driving the wire through the passageway to a predetermined length of the protruding portion of the wire via a first actuator of the sample manipulation system; as well as The distance between the distal end of the wire and the sample is adjusted via a second actuator coupled to the sample manipulation system.

9. The method according to claim 8, further comprising: One or more second images are acquired that include a portion of the sample and the distal end of the wire, and a distance between the distal end of the wire and the sample is adjusted based on the second images.

10. The method of claim 9, wherein the second image is a scanning electron microscope (SEM) image.

11. The method of claim 8, wherein the second actuator is configured to translate and rotate the sample manipulation system with at least four degrees of freedom.

12. The method of claim 8, wherein the image includes at least a portion of the carrier.

13. The method of claim 8, wherein the image is a SEM image or an optical image.

14. The method of claim 8, further comprising attaching the distal end of the wire to the sample.

15. A charged particle microscope, comprising: A sample holder, the sample holder is used to hold the sample; A sample manipulation system, the sample manipulation system comprising: a carrier, the carrier defining a passage; a wire slidably supported and at least partially contained by the carrier, the wire comprising a supported portion and a protruding portion, wherein the supported portion is disposed in the passageway and the protruding portion extends from the carrier for engaging the sample; and a feed mechanism including a first actuator configured to drive the wire along the pathway; a second actuator coupled to the sample manipulation system; at least one detector; and A controller, the controller comprising a processor and a non-transitory memory, the non-transitory memory being used to store computer-readable instructions, wherein by executing the instructions in the processor, the charged-particle microscope is configured to: acquiring an image via the detector; adjusting, via the first actuator, a length of a portion of the wire protruding from the carrier based on the acquired image; and The relative position between the sample and the distal end of the wire is adjusted via the second actuator.

16. A charged particle microscope according to claim 15, further comprising a charged particle source for generating a charged particle beam, and the charged particle microscope is further configured to: guide the charged particle beam toward the sample to attach the sample to the distal end of the wire.

17. The charged particle microscope of claim 15, further comprising an electron source, wherein the detector comprises an electron detector for acquiring one or more SEM images, and wherein adjusting the length of the protruding portion of the wire from the carrier based on the acquired images comprises: The length of the protruding portion of the wire is determined based on the one or more SEM images, and the length of the protruding portion is adjusted based on the determined length of the protruding portion.

Images