Patent Description:
In current systems, the sample is attached to the probe and/or the sample holder using a precursor gas or deposited liquid. Specifically, in some attachment methods a precursor gas is introduced to a volume around the sample, where the gas molecules form deposits on the sample, probe, and/or sample holder when irradiated by a charged particle beam. In another current attachment method, a liquid is first introduced to a sample, probe, and/or sample holder, and the liquid is irradiated with a charged particle beam such that it is cured, forming an attachment bond between the sample and the probe, and/or sample holder. However, while these systems work for many general applications, they each suffer from drawbacks that make them unsuitable for some microscopy investigations.

For example, charged particle microscopy systems investigate samples in sealed chambers to reduce contamination of the optical components, reduce the effects of undesired particulates on the charged particle beam, and have unwanted deposits on the sample. The introduction of a precursor gas and/or liquid adds additional materials to the charged particle microscopy systems' chamber, increasing these undesired effects. Additionally, introducing gas or liquid requires specifically tailored mechanisms that complicate the design and implementation of new charged particle systems, while also adding complex processing steps that are difficult for new users to implement accurately. Finally, for highly reactive samples, traditional precursor gases cannot be used as the introduction of the gases may cause degradation of the sample surface and/or cause the sample to be more reactive to a charged particle beam when subsequent post-attachment milling or imaging is performed. Because of this, there is a desire to have new attachment and sample manipulation systems and processes to allow for the imaging and investigation of highly reactive materials.

<NPL> relate to a site-specific, cryogenic focused ion beam (FIB) method for the preparation of atom probe-tomography (APT) specimens from a frozen liquid/solid interface.

Methods and systems for creating attachments between a sample manipulator and a sample within a charged particle systems are disclosed herein. Methods include translating a sample manipulator so that it is proximate to a sample, and milling portions of the sample manipulator such that portions are removed. The portion of the sample manipulator proximate to the sample is composed of a high sputter yield material, and the high sputter yield material may be the material milled with the charged particle beam such that it is removed from the sample manipulator. According to the present disclosure, the portions of the sample manipulator are milled such that at least some of the removed high sputter yield material redeposits to form an attachment between the sample manipulator and the sample. According to the present disclosure, a high sputter yield material corresponds to a material that yields a greater number of atoms per ion when irradiated with a specific ion beam species and voltage than silicon or tungsten.

Systems for creating attachments between a sample manipulator and a sample within a charged particle systems according to the present disclosure, may comprise a charged particle emitter configured to emit charged particles towards a sample, a sample holder configured to support the sample, an optical column configured to direct the charged particles to be incident on the sample, a detector system configured to detect emissions from the sample due to irradiation by the charged particles, a sample manipulator configured to be translated so that it is proximate to a sample, wherein a portion of the sample manipulator is composed of a high sputter yield material. The systems further include one or more processors, and a memory storing non-transitory computer readable instructions, that when executed by the one or more processors, cause the microscope system to translate a sample manipulator so that it is proximate to a sample, and milling high sputter yield portions of the sample manipulator such that material that is removed via the milling redeposits to form an attachment between the sample manipulator and the sample.

Although embodiments of the present invention employ a non transitory computer readable medium such as is set out in the appended claims, the invention can equally be embodied as a computer program, optionally embodied on a non transitory medium or otherwise carried by an electromagnetic signal or the like.

In the figures, the left-most digit(s) of a reference number identify the figure in which the reference number first appears. The same reference numbers in different figures indicates similar or identical items.

Methods and systems for performing sample lift-out and protective cap placement for highly reactive materials within charged particle microscopy systems are disclosed. More specifically, the disclosure includes methods and systems in which a nesting void is created in a support structure, a sample is translated such that at least a portion of the sample is located within the nesting void, and then material from a region of the support structure that defines the nesting void is milled away. The material from the region of the support structure is located proximate to the sample such that at least some of the removed material redeposits to form one or more attachment bonds between the sample and the remaining portions of the support structure. In this way, the sample can be attached to the sample holder without requiring a precursor gas or other type of attaching medium to be added to the charged particle system. Additionally, because the attachment is formed by the passive redeposition of milled material, there is much less opportunity for reactions and/or other types of damage to the sample. This allows for samples composed of highly reactive materials, such as those found in lithium-based battery technology, to be attached to a sample holder without damaging the sample. Once the sample is attached to the sample holder in this way, one or more regions of interest of the sample can be imaged and/or investigated using one or more methodologies, such as but not limited to, serial sectioning tomography on the sample, enhanced insertable backscatter detector (CBS) analysis on the sample, and electron backscatter diffraction (EBSD) analysis on the sample.

Additionally, methods and systems for creating attachments between a sample manipulator and a sample within a charged particle system are also disclosed herein. Specifically, the disclosure includes methods and systems in which a sample is attached to a holder or manipulator via irradiation of a high sputter yield material proximate to the sample. Initially, a sample manipulator is translated such that a portion of the manipulator that is made of a high sputter yield material is located proximate to the sample (e.g., within a micron). Then, a region of the high sputter yield material proximate to the sample is milled away using a charged particle beam such that at least some of the removed high sputter yield material redeposits to form an attachment between the sample manipulator and the sample. According to the present disclosure, a high sputter yield material corresponds to a material that yields a greater number of atoms per ion when irradiated with a specific ion beam species and voltage than silicon or tungsten. For example, a high sputter yield material is a high sputter yield material defined as a material that emits greater than <NUM>, <NUM>, <NUM>, or <NUM> atoms per ion when the material is irradiated with a <NUM> kV Ga+ focused ion beam, such as copper or zinc.

Generally, in the figures, elements that are likely to be included in a given example are illustrated in solid lines, while elements that are optional to a given example are illustrated in broken lines. However, elements that are illustrated in solid lines are not essential to all examples of the present disclosure, and an element shown in solid lines may be omitted from a particular example without departing from the scope of the present disclosure.

<FIG> illustrates example systems <NUM> for performing sample lift-out and protective cap placement for highly reactive materials, and/or for creating attachments between a sample manipulator and a sample within charged particle microscopy systems. Specifically, <FIG> shows an example environment <NUM> that includes an example microscope system(s) <NUM> for creating attachments between a sample manipulator <NUM> and a sample <NUM> and/or performing sample lift-out and protective cap placement for highly reactive materials in situ. It is noted that present disclosure is not limited to environments that include microscopes, and that in some embodiments the environments <NUM> may include a different type of system that is configured to manipulate and/or otherwise examine samples <NUM>.

The example microscope system(s) <NUM> may be or include one or more different types of optical, and/or charged particle microscopes, such as, but not limited to, a scanning electron microscope (SEM), a scanning transmission electron microscope (STEM), a transmission electron microscope (TEM), a charged particle microscope (CPM), a cryo-compatible microscope, focused ion beam (FIB) microscope, dual beam microscopy system, or combinations thereof. <FIG> shows the example microscope system(s) <NUM> as being a dual beam microscopy system including a STEM column <NUM> and a FIB column <NUM>.

<FIG> depicts the example microscope system(s) <NUM> as including STEM column <NUM> for irradiating the sample <NUM> with a charged particle beam <NUM>. The STEM column <NUM> includes an electron source <NUM> (e.g., a thermal electron source, Schottky-emission source, field emission source, etc.) that emits an electron beam <NUM> along an electron emission axis <NUM> and towards the sample <NUM>. The electron emission axis <NUM> is a central axis that runs along the length of the example microscope system(s) <NUM> from the electron source <NUM> and through the sample <NUM>. While <FIG> depicts the example microscope system(s) <NUM> as including an electron source <NUM>, in other embodiments the STEM column <NUM> may comprise a charged particle source, such as an ion source, configured to emit a plurality of charged particles toward the sample <NUM>.

An accelerator lens <NUM> accelerates/decelerates, focuses, and/or directs the electron beam <NUM> towards an electron focusing column <NUM>. The electron focusing column <NUM> focuses the electron beam <NUM> so that it is incident on at least a portion of the sample <NUM>. Additionally, the focusing column <NUM> may correct and/or tune aberrations (e.g., geometric aberrations, chromatic aberrations) of the electron beam <NUM>. In some embodiments, the electron focusing column <NUM> may include one or more of an aperture, deflectors, transfer lenses, scan coils, condenser lenses, objective lens, etc. that together focus electrons from electron source <NUM> onto a small spot on the sample <NUM>. Different locations of the sample <NUM> may be scanned by adjusting the electron beam direction via the deflectors and/or scan coils. In this way, the electron beam <NUM> may act as an imaging beam that is scanned across a surface layer of the sample (i.e., the surface of the layer proximate the STEM column <NUM> and/or that is irradiated by the electron beam <NUM>). This irradiation of the surface layer of the sample <NUM> causes the component electrons of the electron beam <NUM> to interact with component elements/molecules/features of the sample, such that component elements/molecules/features cause emissions <NUM> to be emitted by the sample <NUM>. The specific emissions that are released are based on the corresponding elements/molecules/features that caused them to be emitted, such that the emissions can be analyzed to determine information about the corresponding elements/molecules. Additionally, while <FIG> illustrates the emissions <NUM> as traveling downstream of the sample <NUM>, a person having skill in the art would understand that emissions may be released in other directions, including but not limited to towards the charged particle source <NUM>.

<FIG> further illustrates detector systems <NUM>(a) and <NUM>(b) for detecting emissions <NUM> resultant from the electron beam <NUM> being incident on the sample <NUM>. The detector system <NUM> may comprise one or more detectors positioned or otherwise configured to detect such emissions. For example, a charged particle system according to the present invention may include a detector system <NUM>(a) positioned below the sample <NUM>, a detector system <NUM>(b) positioned above the sample <NUM>, or both. In various embodiments, different detectors and/or different portions of single detectors may be configured to detect different types of emissions, or be configured such that different parameters of the emissions detected by the different detectors and/or different portions. The detector system <NUM> is further configured to generate a data/data signal corresponding to the detected emissions, and transmit the data/data signal to one or more computing devices <NUM>.

While <FIG> also depicts the example microscope system(s) <NUM> as including FIB column <NUM> for removing portions of the sample <NUM> or other object in the microscope chamber <NUM>. For example, the FIB column <NUM> may be used to mill away portions of a specimen body to reveal or otherwise create the sample <NUM>. In other embodiments the example microscope system(s) <NUM> may include other types of delayering components, such as a laser, a mechanical blade (e.g., a diamond blade), an electron beam, etc. The FIB column <NUM> is shown as including a charged particle emitter <NUM> configured to emit a plurality of ions <NUM> along an ion emission axis <NUM>.

The ion emission axis <NUM> is a central axis that runs from the charged particle emitter <NUM> and through the sample <NUM>. The FIB column <NUM> further includes an ion focusing column <NUM> that comprises one or more of an aperture, deflectors, transfer lenses, scan coils, condenser lenses, objective lens, etc. that together focus ions from charged particle emitter <NUM> onto a small spot on the sample <NUM>. In this way, the elements in the ion focusing column <NUM> may cause the ions emitted by the charged particle emitter <NUM> to mill away or otherwise remove one or more portions of the sample <NUM> or other body. For example, during slice and view imaging the FIB column <NUM> may be configured to cause a surface layer of the sample <NUM> having a known thickness to be removed from the sample <NUM> between image acquisitions.

<FIG> further illustrates the example microscope system(s) <NUM> as further including a sample holder <NUM>, a sample manipulator <NUM>, and a sample loading chamber <NUM>. The sample holder <NUM> is configured to hold the sample <NUM>, and can translate, rotate, and/or tilt the sample <NUM> in relation to the example microscope system(s) <NUM>. For example, the sample holder <NUM> may comprise a grid or structure on which a sample or a specimen is to be attached and/or otherwise held by. Additionally, the sample manipulator <NUM> is a mechanism in the microscope chamber <NUM> that is able to interact with the sample <NUM> such that the sample may be translated, angled, and/or rotated. For example, <FIG> shows the sample manipulator as comprising a probe portion that extends from a body, and to which the sample can be attached. The sample loading chamber <NUM> may be sealable from the microscope chamber <NUM>, and may allow the sample holder <NUM> to be retracted into it such that a user may be able to access and/or interact with the sample holder <NUM> while it is in the sample loading chamber <NUM>.

The environment <NUM> is also shown as including one or more computing device(s) <NUM>. Those skilled in the art will appreciate that the computing devices <NUM> depicted in <FIG> are merely illustrative and are not intended to limit the scope of the present disclosure. The computing system and devices may include any combination of hardware or software that can perform the indicated functions, including computers, network devices, internet appliances, PDAs, wireless phones, controllers, oscilloscopes, amplifiers, etc. The computing devices <NUM> may also be connected to other devices that are not illustrated, or instead may operate as a stand-alone system.

It is also noted that one or more of the computing device(s) <NUM> may be a component of the example microscope system(s) <NUM>, may be a separate device from the example microscope system(s) <NUM> which is in communication with the example microscope system(s) <NUM> via a network communication interface, or a combination thereof. For example, an example microscope system(s) <NUM> may include a first computing device <NUM> that is a component portion of the example microscope system(s) <NUM>, and which acts as a controller that drives the operation of the example charged particle microscope system(s) <NUM> (e.g., adjust the scanning location on the sample by operating the scan coils, etc.). In such an embodiment the example microscope system(s) <NUM> may also include a second computing device <NUM> that is a desktop computer separate from the example microscope system(s) <NUM>, and which is executable to process data received from the detector system <NUM> to generate images of the sample <NUM> and/or perform other types of analysis or post-processing of detector data. The computing devices <NUM> may further be configured to receive user selections via a keyboard, mouse, touchpad, touchscreen, etc. The computing device(s) <NUM> are configured to generate images of the surface layer of the sample <NUM> within the example microscope system(s) <NUM> based on data and/or the data signal from the detector system <NUM>.

Additionally, the computing device(s) <NUM> are configured to control the FIB column <NUM>, the sample manipulator <NUM>, and/or sample holder <NUM> to allow for the performance of sample lift-out and protective cap placement for highly reactive materials within charged particle microscopy systems <NUM>. For example, the computing devices <NUM> may cause the FIB column <NUM> to mill a nesting void in a support structure (e.g., a sample grid, a sample holder, or other structure which allows the sample to be imaged/investigated when the sample is attached to it) using the plurality of ions <NUM>. One or more user selections, an automation program, or a combination thereof may allow the computing devices <NUM> to cause a sample holder <NUM> or sample manipulation device <NUM> to be translated (e.g., translated, angled, and/or rotated) such that at least a portion of the sample <NUM> is positioned within the nesting void. Once the sample <NUM> is positioned at least partially within the nesting void, the computing device <NUM> may cause the FIB column <NUM> to mill away portions of the support structure near the part of the sample and/or which define the nesting. User selections, an automation program, or a combination thereof select the portions of the support structure that are to be milled in this way such that the milled material redeposits to form an attachment bond between the support structure and the portion of the sample <NUM> in the nesting void. In this way, interconnections are formed between the sample <NUM> and the support structure such that the sample <NUM> is held in place for further processing/imaging without requiring deposition gases or other material to be added to the microscope chamber <NUM>. In some embodiments, the computing devices <NUM> may be further configured to cause the example microscope system(s) <NUM> to prepare the sample <NUM> prior to attachment (e.g., remove it from a larger specimen body, reveal a surface/structure of interest), process the sample to prepare it for imaging/investigation, or perform an imaging/investigation of one or more regions of the sample <NUM>.

Alternatively, or in addition, the computing devices <NUM> may be configured to create one or more attachments between the sample manipulator <NUM> and the sample <NUM> within charged particle systems <NUM> without the need for additional deposition gases or other material to be added to the microscope chamber <NUM>. For example, the computing devices <NUM> may cause a high sputter yield material (e.g., copper) to be positioned proximate to the sample <NUM>. The high sputter yield material may be optionally attached to a sample manipulator, a sample manipulator may itself comprise the high sputter yield material (e.g., purchased with such a coating, or purchased without where the coating was added via deposition in situ or ex situ).

User selections, an automation program, or a combination thereof may then cause the computing devices <NUM> to activate the FIB column <NUM> to mill away portions of the high sputter yield material proximate to the sample while leaving one or more other portions of the high sputter yield material located close to the sample manipulator remaining unmilled. In this way, while some portions of the high sputter yield material near the sample are removed, there remain portions of the material that are still within <NUM> microns, <NUM> micron, or closer to the sample. Thus, when the milled high sputter yield material redeposits, it forms one or more attachment bonds between the sample and the sample manipulator.

<FIG> further includes a schematic diagram illustrating an example computing architecture <NUM> of the computing devices <NUM>. Example computing architecture <NUM> illustrates additional details of hardware and software components that can be used to implement the techniques described in the present disclosure. Persons having skill in the art would understand that the computing architecture <NUM> may be implemented in a single computing device <NUM> or may be implemented across multiple computing devices. For example, individual modules and/or data constructs depicted in computing architecture <NUM> may be executed by and/or stored on different computing devices <NUM>. In this way, different process steps of the inventive methods disclosed herein may be executed and/or performed by separate computing devices <NUM> and in various orders within the scope of the present disclosure. In other words, the functionality provided by the illustrated components may in some implementations be combined in fewer components or distributed in additional components. Similarly, in some implementations, the functionality of some of the illustrated components may not be provided and/or other additional functionality may be available.

In the example computing architecture <NUM>, the computing device includes one or more processors <NUM> and memory <NUM> communicatively coupled to the one or more processors <NUM>. While not intended to be limiting, example computing architecture <NUM> is shown as including a control module <NUM> stored in the memory <NUM>. As used herein, the term "module" is intended to represent example divisions of executable instructions for purposes of discussion, and is not intended to represent any type of requirement or required method, manner, or organization. Accordingly, while various "modules" are described, their functionality and/or similar functionality could be arranged differently (e.g., combined into a fewer number of modules, broken into a larger number of modules, etc.). Further, while certain functions and modules are described herein as being implemented by software and/or firmware executable on a processor, in other instances, any or all of modules can be implemented in whole or in part by hardware (e.g., a specialized processing unit, etc.) to execute the described functions. As discussed above in various implementations, the modules described herein in association with the example computing architecture <NUM> can be executed across multiple computing devices <NUM>.

The control module <NUM> can be executable by the processors <NUM> to cause a computing device <NUM> and/or example microscope system(s) <NUM> to take one or more actions and/or perform functions or maintenance of the systems. In some embodiments, the control module <NUM> may cause the example microscope system(s) <NUM> to perform a sample lift-out and/or protective cap placement for highly reactive materials within charged particle microscopy systems <NUM> For example, the control module <NUM> may cause the example microscope system(s) <NUM> to perform such a process using example processes described in the remarks regarding <FIG>. Alternatively, or in addition the control module <NUM> may be configured to cause the example microscope system(s) <NUM> to create one or more attachments between the sample manipulator <NUM> and the sample <NUM> within charged particle systems <NUM> without the need for additional deposition gases or other material to be added to the microscope chamber <NUM>. For example, the control module <NUM> may cause the example microscope system(s) <NUM> to perform such a process using example processes described in the remarks regarding <FIG>.

As discussed above, the computing devices <NUM> include one or more processors <NUM> configured to execute instructions, applications, or programs stored in a memory(s) <NUM> accessible to the one or more processors. In some examples, the one or more processors <NUM> may include hardware processors that include, without limitation, a hardware central processing unit (CPU), a graphics processing unit (GPU), and so on. While in many instances the techniques are described herein as being performed by the one or more processors <NUM>, in some instances the techniques may be implemented by one or more hardware logic components, such as a field programmable gate array (FPGA), a complex programmable logic device (CPLD), an application specific integrated circuit (ASIC), a system-on-chip (SoC), or a combination thereof.

The memories <NUM> accessible to the one or more processors <NUM> are examples of computer-readable media. Computer-readable media may include two types of computer-readable media, namely computer storage media and communication media. Computer storage media may include volatile and non-volatile, removable, and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that may be used to store the desired information and which may be accessed by a computing device. In general, computer storage media may include computer executable instructions that, when executed by one or more processing units, cause various functions and/or operations described herein to be performed. In contrast, communication media embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave, or other transmission mechanism. As defined herein, computer storage media does not include communication media.

Those skilled in the art will also appreciate that items or portions thereof may be transferred between memory <NUM> and other storage devices for purposes of memory management and data integrity. Alternatively, in other implementations, some or all the software components may execute in memory on another device and communicate with the computing devices <NUM>. Some or all of the system components or data structures may also be stored (e.g., as instructions or structured data) on a non-transitory, computer accessible medium or a portable article to be read by an appropriate drive, various examples of which are described above. In some implementations, instructions stored on a computer-accessible medium separate from the computing devices <NUM> may be transmitted to the computing devices <NUM> via transmission media or signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as a wireless link. Various implementations may further include receiving, sending, or storing instructions and/or data implemented in accordance with the foregoing description upon a computer-accessible medium.

<FIG> and <FIG> are flow diagrams of illustrative processes shown as a collection of blocks in a logical flow graph, which represent a sequence of operations that can be implemented in hardware, software, or a combination thereof. In the context of software, the blocks represent computer-executable instructions stored on one or more computer-readable storage media that, when executed by one or more processors, perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, and the like that perform particular functions or implement particular abstract data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described blocks can be combined in any order and/or in parallel to implement the processes.

Specifically, <FIG> is a flow diagram of an illustrative process <NUM> for performing sample lift-out and protective cap placement for highly reactive materials within charged particle microscopy systems. The process <NUM> may be implemented in example charged particle microscope setup(s) <NUM> and/or by the computing architecture <NUM> described above, or in other environments and architectures.

At <NUM>, the sample is optionally prepared. For example, the sample may be preprocessed to expose a region of interest that is to be imaged and/or investigated. In some embodiments, this may include using a process to form the sample from a larger specimen, such as a sample lift-out procedure where portions of the specimen are milled away to expose a chunk which includes a region of interest, the chunk is attached to a sample manipulator, the chunk is detached from the body of the specimen, and the sample manipulator and/or the specimen is translated so that the chunk moved away from the specimen body. Alternatively, or in addition, a surface of the sample may be milled away and/or polished to expose a region of interest and/or remove damage from the surface to allow for a high-quality image/investigation. In some embodiments, the specimen may correspond to a battery or a portion of a battery, and the sample may be a portion thereof that comprises at least one of lithium, manganese, lithium polymers, lithium cobalt oxides, lithium manganese oxide, lithium manganese cobalt oxides, etc..

At <NUM>, the nesting void is prepared in a support structure. Specifically, the nesting void is prepared in the support structure by removing a volume of material from the support structure to create a volume into which at least a portion of the sample can be housed. For example, a charged particle beam can be used to mill away material from the support structure. The nesting void may correspond to a hole, a pocket, or an inset volume into which a portion of the sample can be inserted. In some embodiments, the support structure may be a sample holder having a beveled edge (e.g., a <NUM>-degree beveled edge), and the nesting void may be a portion of the sample holder near the beveled edge that is milled away with a focused ion beam. Such a nesting void may be milled so that when the sample is inserted in the nesting void, at least a portion of the beveled holder extends beyond the sample.

In various embodiments, the support structure may correspond to one or more of a sample grid, a sample holder, or other structure which allows the sample to be imaged/investigated when the sample is attached to it. The support structure may be at least partially composed of many different materials, including but not limited to, silicon, aluminum, copper, etc. In some embodiments, the support structure is composed of an inert material that is not reactive to the charged particle beam.

At <NUM>, the sample is translated so that at least a portion of the sample is positioned within the nesting void. For example, the sample may be attached to a moveable sample manipulator (e.g., a sample probe) which is translated, angled, and/or rotated so that at least a portion of the sample is housed within the nesting void. That is, the sample is positioned such that the portion of the sample is located in a volume where the portion of the support structure that was milled away was located.

At <NUM>, portions of the support structure are milled away. Specifically, portions of the support structure near the portion of the sample and/or which define the nesting void are milled away from the support structure. In some embodiments, an edge/surface of the support structure that defines the nesting void is milled away along a depth of the sample. Alternatively, or in addition, multiple portions of the support structure that partially define the nesting void may be milled away in this manner. For example, a charged particle beam may be used to mill away multiple disparate portions of the support structure that each partially define the nesting void along one or more surfaces of the nesting void. Such multiple disparate portions of the support structure may be milled such that in between the milled portions, projections of the support structure remain proximate to the sample.

At <NUM>, the milled material is allowed to redeposit to form an attachment bond between the sample and the support structure. While the portions of the support structure are milled away at step <NUM> and immediately afterward, the sample is held in a constant position so that the material which was milled away is allowed to settle on the un-milled portion of the support structure and/or the sample. In this way, the milled material is allowed to form deposits that interconnect to form attachment bonds between the support structure and the sample. In this way, by allowing the milled material to redeposit, one or more attachment bonds may be created between the sample and the un-milled portions of the support structure that hold the sample in place. Not only are these attachment bonds easy for a user to create/easily automated, because these attachment bonds are created without the introduction of a precursor gas or a liquid, this process <NUM> can be used to attach samples composed of highly reactive materials to the support structure.

At <NUM>, the sample is optionally processed to prepare it for imaging and/ investigation. For example, portions of the sample can be milled away with a charged particle beam to expose a region of interest in the sample, polished to remove damage from the surface of the sample, or a combination thereof. In some embodiments, after the exposed surface is imaged/investigated, the sample may be processed one or more additional times so that different regions of interest are exposed for imaging/investigation. In some embodiments, when the sample is milled in step <NUM>, the charged particle beam is angled such that the charged particle beam first mills through a portion of the support structure before it begins removing portions of the sample. In this way, the portion of the support structure is able to be used as a protective cap to prevent curtaining in the exposed sample surface. Thus, in addition to the attachment bonds being created without the introduction of the precursor gas, process <NUM> may also allow for a protective cap to be utilized without the introduction of the precursor gas. In some embodiments, processing the sample may include milling away an attachment bond between the sample and the sample manipulator such that the sample is disconnected from the sample manipulator. In other embodiments, processing the sample may include milling away a portion of a sample probe such that a tip of the sample probe remains attached to the sample and a remaining portion of the sample probe is disconnected from the sample.

At <NUM>, the sample is imaged and/or investigated. In various embodiments, the imaging and/or investigation of the sample corresponds to performing one or more of serial sectioning tomography on a region of interest on the sample, enhanced insertable backscatter detector (CBS) analysis on the region of interest, and electron backscatter diffraction (EBSD) analysis on the region of interest. Steps <NUM> and <NUM> may be iterated so that multiple regions of interest within the sample may be imaged and/or investigated.

<FIG> and <FIG> are visual flow diagrams that illustrate example processes for performing sample lift-out and protective cap placement for highly reactive materials according to the present disclosure. Specifically, <FIG> shows a series of captured images <NUM> that demonstrate an example performance of an example process <NUM> described in the remarks regarding <FIG>.

Image <NUM> shows the optional creation of a sample <NUM> from a specimen body <NUM>. Specifically, image <NUM> shows a state where one or more volumes <NUM> of the specimen body <NUM> surrounding the sample <NUM> are milled away using a charged particle beam (e.g., an ion beam). Image <NUM> shows a subsequent state of the example process where a sample manipulator <NUM> is attached to the sample <NUM>. For example, the sample <NUM> may be attached to the sample manipulator <NUM> using a deposition gas, or by an attachment process described in association with <FIG>. Once the sample <NUM> is attached to the sample manipulator <NUM>, the final portions <NUM> of the specimen that had previously connected the sample to the specimen body are milled away. Once the sample <NUM> is fully detached from the specimen body in this way, the sample manipulator <NUM> can translate the sample <NUM> away from the specimen body <NUM>.

Image <NUM> shows a state where a nesting void <NUM> is prepared in a support structure <NUM>. For example, a charged particle beam can be used to mill away material from the support structure <NUM>. The nesting void <NUM> may correspond to a hole, a pocket, a cavity, or an inset volume into which a portion of the sample can be inserted. While not shown in image <NUM>, the nesting void may in some embodiments correspond to a region next to and/or abutting a raised structure/portion of the support structure such that when a sample is translated into the nesting void a portion of the sample is proximate to and/or abuts the raised structure/portion of the support structure. In various embodiments, the support structure <NUM> may correspond to one or more of a sample grid, a sample holder, or other structure which allows the sample to be imaged/investigated when the sample is attached to it. The support structure may be at least partially composed of many different materials, including but not limited to silicon, aluminum, copper, etc..

Image <NUM> shows the state after the sample <NUM> is translated, tilted, rotated, or otherwise manipulated in relation to the support structure so that at least a portion of the sample is positioned within the nesting void <NUM>. The sample is shown as being be attached to the moveable sample manipulator <NUM> (i.e., a sample probe), which has been translated, angled, and/or rotated so that at least a portion of the sample <NUM> is housed within the nesting void <NUM>.

Image <NUM> shows the state of image <NUM>, where a plurality of milling locations <NUM> have been mapped onto it. Specifically, Image <NUM> shows a plurality of milling locations <NUM> that each correspond to a portion of the support structure <NUM> that is to be milled using a charged particle beam. Image <NUM> shows a state of the process after the portions <NUM> of the sample holder <NUM> have been milled away, and the milled material is allowed to redeposit to form attachment bonds <NUM> between the sample <NUM> and the support structure <NUM>.

<FIG> are captured images that show example results of sample lift-out and protective cap placement for highly reactive materials according to the present disclosure, and according to the prior art. <FIG> is an image <NUM> of sample <NUM> from <FIG> after it has been further processed to prepare it for imaging and/ investigation. For example, portions of the sample <NUM> have be milled away with a charged particle beam to expose a clean surface <NUM> of a region of interest in the sample, and then polished to remove damage from the surface of the sample. Specifically, <FIG> shows an example where the portion of the sample <NUM> being removed and cleaned such that a clean reactive surface <NUM>(a) (i.e., a clean surface of a portion of the sample composed of a reactive material) and a clean stable surface <NUM>(b) (i.e., a clean surface of a portion of the sample composed of a non-reactive material) are exposed. In such embodiments where a sample is composed of both a stable and reactive material, milling may be performed through the stable material first such that the stable material acts as a cap that reduces curtaining in the clean reactive surface <NUM>(a). Alternatively, in some embodiments the milling may be performed such that portions of the support structure <NUM> are first milled through such that the support structure <NUM> acts as a cap that reduces curtaining in the clean reactive surface <NUM>(a). Using the processes described herein, high-quality EBSD maps and/or band contrast maps may be obtained for clean surfaces <NUM> of highly reactive materials, which were previously not possible with prior techniques.

Additionally, the processes described herein in some embodiments have been shown to preserve the crystallinity of highly reactive materials as evidenced by acquired Kikuchi patterns of portions of such clean surfaces <NUM>. <FIG> shows an image <NUM> where a sample <NUM> has been inserted into a nesting void <NUM> in a support structure <NUM> and attached using techniques according to the present disclosure. <FIG> further shows the use of <NUM> for aid in user processing and/or automated processing and investigation of regions of interest in the sample <NUM>.

<FIG> shows the results of a sample lift-out and protective cap placement for a highly reactive material using prior art techniques. As can be seen, when an attachment <NUM> was formed between the highly reactive sample <NUM> and the support structure <NUM>, the sample <NUM> underwent massive damage. This damage occurs at two separate steps of prior art systems. Firstly, the sample <NUM> may be damaged by a reaction with an outside material that is introduced to form the attachment (e.g., deposition gas, bonding liquid). Secondly, even if the damage in such an introduction of outside material is not catastrophic, the reactions between the outside material and the highly reactive material <NUM> can cause the surface of the sample <NUM> to have subsequent catastrophic reactions when irradiated with a charged particle beam. As shown in image <NUM>, because of these reactions, the prior art techniques for in situ attachment of samples do not work for highly reactive materials.

<FIG> is a flow diagram of an illustrative process <NUM> for creating attachments between a sample manipulator and a sample within a charged particle system. The process <NUM> may be implemented in example processes <NUM>-<NUM>, example charged particle microscope setup(s) <NUM>, and/or by the computing architecture <NUM> described above, or in other environments and architectures.

At <NUM>, a high sputter yield material is optionally attached to a sample manipulator. Specifically, a high sputter yield material, such as copper, may be attached to a sample manipulator within the chamber of a charged particle system, outside of such a chamber, or a combination thereof. For example, the high sputter yield material may be attached to a probe portion of a sample manipulator using gas deposition attachment where a precursor gas is introduced to a region between the sample manipulator and the high sputter yield material, and then a charged particle beam is used to induce the precursor gas to deposit to form an attachment bond. In another example process, the sample manipulator may be moved into immediate proximity with the high sputter yield material, a charged particle beam may be used to mill away portions of the high sputter yield material proximate to the sample, and the milled material may be allowed to settle to form one or more attachment bonds between the sample manipulator and the high sputter yield material.

Alternatively, in some embodiments of the present process, instead of needing to perform step <NUM>, the sample manipulator comprises a probe that is composed of the high sputter yield material (e.g., purchased with such a coating, or purchased without where the coating was added via deposition in situ or ex situ).

At <NUM>, a sample is caused to be proximate to the sample manipulator. Specifically, the sample and/or the sample manipulator may be moved such that a portion of the sample manipulator that is to be attached to the sample (e.g., a probe, an intermediate body made of high sputter yield material attached in step <NUM>, etc.) are within <NUM> microns of each other, within <NUM> micron of each other, or closer. For example, the sample and/or the sample manipulator may be attached to a movement component and/or otherwise configured to be translated, angled, and/or rotated.

At <NUM> the high sputter yield material is irradiated with a charged particle beam. Specifically, a charged particle beam is used to mill away one or more portions of the high sputter yield material while leaving one or more other portions of the high sputter yield material located close to the sample manipulator remaining unmilled. In this way, while some portions of the high sputter yield material near the sample are removed, there remain portions of the material that are still within <NUM> microns, <NUM> micron, or closer to the sample. For example, three portions located on an edge/surface of the high sputter yield material may be milled, while two portions of the material located between the three portions may remain un-milled.

At <NUM>, the milled high sputter yield material is allowed to redeposit to form an attachment bond between the sample and the sample manipulator. While the portions of the high sputter yield material are milled away at step <NUM> and immediately afterward the sample is held in a constant position so that the material which was milled away is allowed to settle on the un-milled portion of the high sputter yield material and/or the sample. In this way, the milled material is allowed to form deposits that interconnect to form attachment bonds between the high sputter yield material and the sample. By allowing the milled material to redeposit, one or more attachment bonds may be created between the sample and the un-milled portions of the high sputter yield material that hold the sample in place. Not only are these attachment bonds easy for a user to create/easily automated, because these attachment bonds are created without the introduction of a precursor gas or a liquid, this process <NUM> can be used to attach samples made of highly reactive materials to the support structure. Moreover, this process <NUM> allows for attachment bonds to be performed at cryogenic temperatures and/or in a vacuum without requiring specialized microscope mechanisms to be developed or included a charged particle system, and without users needing to learn complex processes.

At <NUM>, the sample is optionally translated by the sample manipulator. For example, the sample manipulator may translate, angle, and/or rotate the sample so that the sample is in a desired position within the charged particle system.

<FIG> show different example embodiments for creating attachments between a sample manipulator and a sample within a charged particle system. For example, <FIG> depicts an example <NUM> where the sample <NUM> is attached to a sample manipulator <NUM> that corresponds to a sample probe made of a high sputter yield material. In this way, when portions <NUM> of the sample probe proximate the sample <NUM> are milled away, the milled material at least partially redeposits to form attachment structures <NUM> between the sample <NUM> and the sample manipulator <NUM>.

<FIG> depicts an example <NUM> where a sample <NUM> is attached to a sample manipulator that corresponds to a sample probe <NUM> that is coated with a high sputter yield material <NUM>. In this way, when portions <NUM> of the coating proximate the sample <NUM> are milled away, the milled material at least partially redeposits to form attachment structures <NUM> between the sample <NUM> and the sample manipulator. <FIG> depicts an example <NUM> where a sample <NUM> is attached to a sample manipulator that corresponds to a sample probe <NUM> that is attached to an intermediary body <NUM> composed of a high sputter yield material. When portions <NUM> of the intermediary body <NUM> proximate the sample <NUM> are milled away, at least some of the milled material redeposits to form attachment structures <NUM> between the sample <NUM> and the intermediary body <NUM>.

<FIG> shows a series of images <NUM> that demonstrate an example performance of an example process for sample lift-out and protective cap placement for highly reactive materials using a sample holder having a beveled edge. Image <NUM> shows an example sample holder <NUM> that has a beveled edge <NUM>. According to the present invention, the beveled edge may be any angle less than <NUM>-degrees. In some embodiments, a charged particle beam may be used to mill away portions of the sample holder <NUM> to create the beveled edge <NUM>. Image <NUM> shows a state where a nesting void <NUM> is prepared in a support structure <NUM> proximate to the beveled edge <NUM>. For example, a charged particle beam can be used to mill away material from the support structure <NUM> such that a hole, a pocket, or an inset volume is created into which a portion of a sample can be inserted.

Image <NUM> shows a sample <NUM> in the process of being translated with a sample manipulator <NUM> such that at least a portion of the sample <NUM> is positioned within the nesting void <NUM>. Specifically, image <NUM> shows an embodiment where the sample <NUM> has been attached to the sample manipulator <NUM> using an intermediate body <NUM> made of high sputter yield material, as shown and described in association with <FIG> and <FIG>. Image <NUM> shows the state after the sample <NUM> has been translated so that at least a portion is positioned within the nesting void <NUM>, and then the sample <NUM> is attached to the sample holder <NUM> by milling away portions of the sample holder <NUM> proximate to the sample such that milled material redeposits forming attachment structures between the sample <NUM> and the sample holder <NUM>.

Claim 1:
A method for creating an attachment between a sample manipulator and a sample within a charged particle system, the method comprising the steps:
translating the sample manipulator (<NUM>, <NUM>, <NUM>, <NUM>) so that it is proximate to the sample (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the portion of the sample manipulator (<NUM>, <NUM>, <NUM>) proximate to the sample (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is composed of a high sputter yield material, wherein the high sputter yield material corresponds to a material that yields a greater number of atoms per ion when irradiated with a specific ion beam species and voltage than silicon or tungsten; and
milling, with a charged particle beam, the high sputter yield material such that portions (<NUM>, <NUM>, <NUM>) of the high sputter yield material is removed from the sample manipulator (<NUM>, <NUM>, <NUM>), and wherein at least some of the removed high sputter yield material redeposits to form an attachment (<NUM>, <NUM>, <NUM>) between the sample manipulator (<NUM>, <NUM>, <NUM>) and the sample (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>).