Carbon-containing precursors for beam-induced deposition

Abstract

This disclosure describes systems, components, and methods for beam induced deposition. A charged particle beam system may include a vacuum chamber. The system may include a charged particle beam source operably coupled with the vacuum chamber and including an emitter section and a column section, the charged particle beam source configured to generate a charged particle beam and direct the charged particle beam into the vacuum chamber. The system may include a precursor source operably coupled with the vacuum chamber and configured to direct a flow of gas containing a precursor into the vacuum chamber. The precursor may comprise a hydrocarbon having a vapor pressure of greater than about 1.6 x 10-4 mbar at about 293 K and about 101.3 kPa, and wherein the hydrocarbon is not naphthalene.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Non - Provisional Application S / N 18 / 512,815, filed on November 17, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments of the present disclosure relate to charged particle beam systems and materials, algorithms, and methods for their operation. Specifically, some embodiments relate to techniques for beam - induced deposition of materials. Background Art

[0004] Charged particle beam systems can be used to prepare samples for further microanalysis, such as in a transmission electron microscope (“TEM”). In the case of extracting a sample from a larger material, such as a multi - layer CMOS wafer, the sample preparation procedure can include deposition and removal operations using a focused ion beam (“FIB”) and an electron beam system. Dual - beam instruments, including an FIB and a scanning electron microscope (“SEM”), can be used to locate and extract a sample from a region of interest (“ROI”) in a wafer for further microanalysis.

[0005] The energy from a charged particle beam (e.g., an ion beam and / or an electron beam) can be used to cause a chemical reaction in a precursor near a substrate surface. In one example, a dual - beam system can include a gas injector system (“GIS”) that delivers a precursor to near the ROI. The gaseous precursor can decompose and / or otherwise activate at least partially near the ROI, resulting in a reaction that forms a material deposit on the sample surface. Material deposition in this manner (referred to as beam - induced deposition) allows for the setting of local and / or patterned layers of material onto the surface of a substrate and / or sample. Additionally, the deposition rate can be controlled using the operating parameters of the charged particle beam and / or the concentration and flux of the precursor near the surface. In this way, beam - induced deposition provides a flexible method for precisely applying materials to a surface. For example, a metal - containing precursor can be decomposed and deposited on a sample to form a conductive trace. Another example is that a carbon - containing material can be formed by the decomposition of a carbon - containing precursor.

[0006] Unfortunately, carbon precursors may contain polycyclic aromatic hydrocarbons (PAHs). Increasingly, environmental health and safety issues associated with the exposure, use, and disposal of PAHs make their application in these technologies undesirable. For example, naphthalene is a common carbon precursor used for depositing carbon films using a dual-beam system. Based on factors including exposure risk, health risk, and environmental degradation risk, the Agency for Toxic Substances and Disease Registry of the Centers for Disease Control and Prevention of the United States lists naphthalene as a more concerning chemical in its Substance Priority List than other more readily identifiable hazards (including plutonium). Therefore, there is a need for a carbon precursor that can reduce the risk to human users and the environment without sacrificing performance and compatibility with existing charged particle beam systems. SUMMARY OF THE INVENTION

[0007] The upcoming aspects and embodiments can be practiced alone or in combination. In a first aspect, a charged particle beam system may include a vacuum chamber. The system may include a charged particle beam source operably coupled to the vacuum chamber and including an emitter section and a column section, the charged particle beam source configured to generate a charged particle beam and direct the charged particle beam into the vacuum chamber. The system may include a precursor source operably coupled to the vacuum chamber and configured to direct a gas stream containing a precursor into the vacuum chamber. The precursor may include a hydrocarbon having a vapor pressure greater than about 1.6×10−4 mbar at about 293K and about 101.3 kPa, and wherein the hydrocarbon is not naphthalene.

[0008] In some embodiments, the hydrocarbon is not included in the Substance Priority List compiled by the Agency for Toxic Substances and Disease Registry of the Centers for Disease Control and Prevention of the United States and publicly available as of 2023. The hydrocarbon may be or may include biphenyl. The biphenyl may include one or more substituents selected from the group consisting of methyl, ethyl, propyl, butyl, amine, amide, acetyl, carboxyl, phosphine, ketone, and ether. The hydrocarbon may be or may include substituted naphthalene. The hydrocarbon may be selected from the group consisting of methane, ethylene, propane, styrene, camphor, menthol, benzoic acid, cyclohexane, cyclohexanone, cyanononane, acetone, methanol, nitromethane, acetonitrile, formic acid, acetic acid, propionic acid, and acrylic acid.

[0009] In some embodiments, under a given set of environmental conditions in the vacuum chamber and for a given sample, the precursor achieves a equilibrium surface coverage θ that is substantially equal to or greater than that of naphthalene, where θ is defined using a relevant adsorption isotherm model. The precursor is characterized by having a substantially equal or greater adsorbed molecular surface mobility than naphthalene under a given set of environmental conditions in the vacuum chamber and for a given sample.

[0010] In some embodiments, the system further includes a sample stage disposed in the vacuum chamber and defining a site therein such that the charged particle beam source and the precursor source are configured to direct a charged particle beam and a gas flow toward the site, respectively.

[0011] In some embodiments, the system further includes: a control circuit operatively coupled to the charged particle beam source and the precursor source; and one or more non-transitory machine-readable storage media operatively coupled to the control circuit and storing instructions. When executed by the system, the instructions cause the system to perform operations. The operations may include directing a gas flow containing a precursor into the vacuum chamber toward a site defined therein, and irradiating a region including the site with a charged particle beam. Irradiating the region may include directing a current density of from about 0.1 pA / μm2 to about 300 pA / μm2 to a surface substantially located at the site. The operations may further include heating the precursor at a temperature of from about 273 K to about 385 K.

[0012] In a second aspect, a method of generating a carbon-containing material in a charged particle beam system includes directing a gas flow containing a precursor into the vacuum chamber of the charged particle beam system, and irradiating a region of a sample with a charged particle beam. The precursor may include a hydrocarbon having a vapor pressure greater than about 1.6×10−4 mbar at about 293 K and about 101.3 kPa, wherein the hydrocarbon is not naphthalene.

[0013] In some embodiments, the charged particle beam may include argon ions, xenon ions, and / or gallium ions. The charged particle beam may include electrons. The charged particle beam may have a current density of from about 0.1 pA / μm 2 to about 300 pA / μm 2 . The charged particle beam may have a beam energy of from about 1 keV to about 50 keV. In some embodiments, the method further includes heating the precursor to a temperature of from about 273 K to about 385 K.

[0014] The terms and expressions employed are used as descriptive terms and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the subject matter claimed. Accordingly, it should be understood that although the subject matter claimed in this disclosure has been specifically disclosed by way of embodiments and optional features, those skilled in the art may make modifications and variations to the concepts disclosed herein, and such modifications and variations are considered to be within the scope of this disclosure as defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The foregoing aspects of the present disclosure and many accompanying advantages will become more readily understood when taken in conjunction with the following detailed description, with reference to the accompanying drawings.

[0016] Figure 1 is a schematic diagram illustrating an example charged particle beam system in accordance with some embodiments of the present disclosure.

[0017] Figure 2 is a schematic diagram illustrating an example charged particle beam system for operating a beam-induced deposition process in accordance with some embodiments of the present disclosure.

[0018] Figure 3 is a block diagram illustrating an example process 300 for beam-induced deposition in accordance with some embodiments of the present disclosure.

[0019] Figure 4A is an electron micrograph of an example sample surface prepared in accordance with some embodiments of the present disclosure, on which a carbon-containing material has been deposited using a biphenyl precursor.

[0020] Figure 4B is prepared in accordance with some embodiments of the present disclosure Figure 4A is an electron micrograph of a partial front view of an example carbon-containing material.

[0021] Figure 4C is an electron micrograph of an example sample surface prepared in accordance with some embodiments of the present disclosure, on which a carbon-containing material has been deposited using an acrylic acid precursor.

[0022] Figures 5A to 5D is a data graph illustrating the influence of the operating parameters of an example charged particle beam system in accordance with the embodiments of the present disclosure on the performance of beam-induced deposition using a biphenyl precursor.

[0023] Figures 6A to 6D is a data graph illustrating the influence of the operating parameters of an example charged particle beam system in accordance with the embodiments of the present disclosure on the performance of beam-induced deposition using an acrylic acid precursor.

[0024] Figures 7A to 7C is a data graph illustrating comparative data generated in electron beam-induced deposition using an example charged particle beam system in accordance with the embodiments of the present disclosure with a biphenyl precursor and a naphthalene precursor.

[0025] Figures 8A to 8B is a data graph illustrating comparative data generated in gallium ion beam-induced deposition using an example charged particle beam system in accordance with the embodiments of the present disclosure with a biphenyl precursor and a naphthalene precursor.

[0026] Figures 9A to 9BIt is a data graph exemplifying comparative data generated in xenon ion beam induced deposition using a biphenyl precursor and a naphthalene precursor under various operating conditions using an exemplary charged particle beam system according to an embodiment of the present disclosure.

[0027] Figures 10A to 10C It is a data graph exemplifying comparative data generated in gallium ion beam induced deposition using a biphenyl precursor and a naphthalene precursor using an exemplary charged particle beam system according to an embodiment of the present disclosure.

[0028] Figures 11A to 11C It is a data graph exemplifying comparative data generated in argon ion beam induced deposition using a biphenyl precursor and a naphthalene precursor using an exemplary charged particle beam system according to an embodiment of the present disclosure.

[0029] In the drawings, unless otherwise noted, the same reference numerals represent the same components in each view. Where appropriate, not all instances of an element need to be labeled to reduce clutter in the drawings. The drawings are not necessarily drawn to scale, but rather focus on illustrating the described principles. Detailed Description

[0030] Although exemplary embodiments have been described, it should be understood that various changes can be made therein without departing from the spirit and scope of the present disclosure. In the following paragraphs, embodiments of charged particle beam instrument systems, components, and methods for beam-induced deposition are described.

[0031] Embodiments of the present disclosure include systems, methods, algorithms, and non-transitory media storing computer-readable instructions for beam-induced deposition. In one exemplary example, a charged particle beam system includes: a vacuum chamber; a charged particle beam source operably coupled to the vacuum chamber and including an emitter section and a column section, the charged particle beam source configured to generate a charged particle beam and direct the charged particle beam into the vacuum chamber; and a precursor source operably coupled to the vacuum chamber and configured to direct a gas stream containing a precursor into the vacuum chamber. In this example, the precursor includes a hydrocarbon having a vapor pressure greater than about 1.6×10 -4 mbar at about 293K and about 101.3kPa, where the hydrocarbon is not naphthalene or does not contain a naphthalene group. As described in the following sections, embodiments of the present disclosure, including those according to the above example, exhibit comparable or improved performance in beam-induced deposition (e.g., carbon-containing materials, films, layers, etc.), while also reducing the environmental, health, and safety risks of such processes.

[0032] For simplicity of description, the following detailed description is centered on embodiments of electron beam assisted deposition and dual beam systems, but it is contemplated that additional and / or alternative instrument systems may be improved by using the techniques described. To this end, the embodiments are not limited to such systems, but are contemplated for use in analytical instrument systems in which chemically stable precursors can be decomposed and / or otherwise induced to form material deposits on a substrate by irradiation. In one illustrative example, a focused ion beam, a broad ion beam, a focused electron beam, a divergent electron beam, high energy photons (e.g., lasers, flash lamps, x-rays, etc.), and other forms of electromagnetic radiation (individually or in combination) can be applied to assist deposition techniques. Similarly, while embodiments of the present disclosure are centered on carbon precursors, additional and / or alternative precursor compositions are contemplated, including but not limited to organometallic compounds (e.g., metallocenes, bis(ferrocenes), metalloaromatics, etc.).

[0033] Figure 1 FIG. 4 is a schematic illustration of an exemplary charged particle beam system 100 in accordance with some embodiments of the present disclosure. Exemplary system 100 includes an electron source 105, an electron beam column 107, an ion source 110, a focused ion beam (“FIB”) column 111, a gas injection system (“GIS”) 115, a vacuum chamber 120, and a sample stage 125. Electron beam column 105 is illustrated as a scanning electron microscope (SEM) column such that exemplary system 100 corresponds to a dual beam FIB-SEM system. Electron beam column 107, FIB column 111, and GIS 115 are illustrated as being operatively coupled to vacuum chamber 120, wherein electron beam column 107 defines a first beam axis A and FIB column 111 defines a second beam axis B. Axes A and B are illustrated as converging on a region of sample 130, wherein GIS 115 is oriented toward this region of sample 130 and is configured to direct a gas stream containing a precursor into the vacuum chamber.

[0034] Electron source 105 may include one or more emitters configured to generate electrons and direct the electrons into electron beam column 107. These emitters may include thermionic emitters, Schottky emitters, field emission source emitters, or combinations thereof, which are operatively coupled to a power system configured to apply a high voltage (e.g., on the order of kilovolts to hundreds of kilovolts) to an emission region of the emitter material. For example, electron source 105 may include lanthanum hexaboride (LaB 6) An emitter crystal to which a high electrical potential is applied to cause electrons to be emitted from the tip of the emitter crystal. In this way, an electron beam is directed into an electron beam column. The electron beam column 107 includes electromagnetic optical devices (e.g., electrostatic lenses, electromagnetic lenses, monochromators, etc.) and apertures configured to shape, focus, defocus, and direct the electron beam according to a set of operating parameters such that the electron beam is focused onto a sample 130. These operating parameters can include beam current, beam energy (e.g., in volts, in electron volts, etc.), magnification parameters, scan pattern, dwell time, and / or one or more pulse parameters. In this way, example system 100 can be used as an SEM to image portions of sample 130 and / or can be used to electron beam assisted deposit material onto sample 130 (e.g., in coordination with GIS 115). In one illustrative example, the beam energy can be from about 1 keV to about 50 keV (including its sub-ranges, fractions, or interpolations). Beam energies below about 1 keV may correspond to reduced pattern fidelity, while beam energies above about 50 keV may reduce the secondary electron yield to levels where deposition may be significantly impaired or nearly ineffective. For this reason, precursor decomposition and deposition reactions can be mediated by secondary electrons emitted from sample 130, which are characterized by energies lower than the primary electrons of the beam (e.g., about 50 eV or less). In this way, the beam energy can be selected at least in part based on the secondary electron emission function of the material of sample 130, which can depend at least in part on the beam energy.

[0035] Ion source 110 may include one or more components configured to generate an ion beam and direct the ions into FIB column 111. These ions may include metal ions and / or non-metal ions (e.g., inert gases, halogens, oxygen, nitrogen, etc.). To this end, ion source 110 may include a plasma source (e.g., inductively coupled plasma source) and / or a metal ion source (e.g., liquid metal ion source). Similar to electron beam column 107, the FIB column may include electromagnetic optics (e.g., electrostatic lenses, electromagnetic lenses, monochromators, etc.) and apertures configured to shape, focus, defocus, and direct the ion beam according to a set of operating parameters such that the ion beam is focused onto sample 130. These operating parameters may include beam current, beam energy (e.g., in volts, in electron volts, etc.), magnification parameters, scan pattern, dwell time, and / or one or more pulse parameters. In this manner, example system 100 may be used as an FIB to remove portions of sample 130 and / or may be used to ion beam assisted deposit material onto sample 130 (e.g., in coordination with GIS 115). Similar to the energy described above with reference to the electron beam, the ion beam energy may be selected (e.g., by the user, by an algorithm initiated by the user, and / or automatically without user intervention) such that the beam delivers sufficient energy for beam-induced deposition to occur, but does not cause the beam to degrade the sample or the precursor without forming a deposited material layer on sample 130. In some embodiments, additional and / or alternative precursor decomposition mechanisms (e.g., surface activation and / or secondary electron re-emission) may be used as the precursor decomposition mechanism, thereby allowing the ion beam energy to be determined at least in part based on the relationship between the beam energy, the sample material properties, and the energy characteristics of the precursor deposition reaction mechanism. Advantageously, ion beam induced deposition may result in a relatively high yield compared to electron beam induced deposition, at least in part based on the combined effect of multiple energy transfer paths.

[0036] The GIS 115 includes constituent elements that jointly allow the GIS 115 to generate a gas stream containing a precursor and direct the gas stream to a vacuum chamber. The components of the GIS 115 may include a carrier gas inlet, a nozzle 119, and a conduit fluidly coupling the nozzle 119 to a precursor reservoir 117. The precursor reservoir 117 may include a substantially non-reactive container (e.g., a ceramic crucible, a PTFE housing, a non-reactive metal or alloy, etc.) that is at least partially exposed to the conduit. In this way, the vapor generated from the precursor disposed in the precursor reservoir 117 can be directed to the nozzle and into the vacuum chamber (e.g., by pressure-driven flow caused by a pressure gradient relative to the vacuum of the vacuum chamber). In some embodiments, the GIS 115 includes a carrier gas inlet fluidly coupled to the nozzle 119 via a conduit. In this way, the precursor can be entrained in the carrier gas stream and directed to the nozzle and into the vacuum chamber. Additionally and / or alternatively, the precursor may include a gas under standard conditions and may be introduced into the GIS 115 via a gas inlet provided as part of the GIS 115.

[0037] In an illustrative example, the precursor may be or may include a material that is solid at standard temperature and pressure and at least partially sublimes at reduced pressure and a temperature above about 273 K to form a vapor. To this end, the GIS 115 may include a heating circuit that is thermally coupled to the precursor reservoir and is configured to heat the precursor to a temperature range that causes at least partial evaporation into the carrier gas stream. In some embodiments, the temperature may be in the range of about 273 K to about 385 K (including its sub-ranges, fractions, and interpolations). As part of controlling the composition of the gas stream entering the vacuum chamber, the temperature may be selected at least in part based on an estimate of the vapor pressure of the precursor. Such an estimate may be determined using empirically derived heuristics for a given charged particle beam system and / or may be derived using the first principles of thermodynamics. In some cases, the temperature and carrier gas flow rate may be selected at least in part based on an operating window determined from experimental calibration of a given charged particle beam system (e.g., for a given sample material and precursor material). Examples of the experimental data are described in more detail. Figures 5A to 6C Examples of the experimental data are described in more detail.

[0038] The operation of one or more components of the example system 100 may be controlled by a control circuit (e.g., Figure 2The control system 215) coordinates according to machine-executable instructions (e.g., software, firmware, etc.) that can be stored in a machine-readable storage medium and / or received from an external system via wired and / or wireless communication technologies (e.g., via a WiFi or Bluetooth link). For this purpose, the components of the example system can be automatic (e.g., operate without human intervention), pseudo-automatic (e.g., operate with limited human intervention to initiate operations, analyze outputs, confirm, etc.), or manually operated (e.g., where the various operations of the example system 100 are performed by a human user). In an illustrative example, the sample stage 125 can be mechanically coupled to the automation stage controller 127, allowing the sample 130 to be reversibly tilted relative to the beam axes A and B such that the surface of the sample is substantially perpendicular to a given beam axis during the operation of the corresponding charged particle beam source. In this way, the operation of the given beam source can be coordinated with the operation of the stage controller 127. Similarly, the operation of the GIS 115 can be coordinated with the operation of the stage controller 127 and the given beam source (e.g., the electron beam source 105 and the column 107), as described in more detail with reference to Figures 2 to 3 is described in more detail.

[0039] Embodiments of the present disclosure omit one or more components of the example system 100. For example, one or more of the sources 105 and 110 and / or the columns 107 and 111 can be omitted. In an illustrative example, an SEM system can be configured to perform the operations of the beam-induced deposition process of the present disclosure. Similarly, a FIB system other than a dual-beam FIB-SEM (e.g., a FIB system in which two or more beam axes do not converge on a given area of the sample 130) can include a GIS 115 that is oriented to converge with the second beam axis B.

[0040] Figure 2 is a schematic diagram of an example charged particle beam system 200 that performs the operations of a beam-induced deposition process according to some embodiments of the present disclosure. The example system 200 can include and / or omit some of the components of the example system 100 described with reference to Figure 1 For this purpose, the example system 200 includes an SEM 205 (e.g., including an electron source 105 and an electron beam column 107), a FIB 210 (e.g., including an ion source 110 and a FIB column 111), a GIS 115, a vacuum chamber 120, and a sample stage 125 to which the sample 130 can be mechanically coupled. The example system 200 includes an electronic control circuit 215, as described in more detail with reference to Figure 3 By the operation of this electronic control circuit, at least a part of the beam-induced deposition process can be coordinated.

[0041] Operations for a beam-induced deposition process can include positioning a sample in a vacuum chamber such that an SEM 205, FIB 210, and / or GIS 115 are configured to direct a charged particle beam 220 and / or a gas stream 225 to an area of interest (ROI) 230 on the surface of the sample 235, respectively. In the case where the charged particle beam 220 and the gas stream 225 substantially converge, the ROI 230 can include a site in the vacuum chamber 120. In such a case, the site can be at least partially defined by the intersection of the beam axes A and B and the position of the gas stream 225 and the sample stage 125 in the vacuum chamber 120. In some embodiments, the GIS 115 can be repositioned relative to the site such that the GIS nozzle 119 can be moved relative to the sample 130, and the average concentration of the precursor at the surface of the sample 235 can be controlled independently of the composition of the gas stream 225 itself (e.g., as determined by the operating parameters of the GIS 115).

[0042] A variety of techniques can be used to estimate and / or measure the offset between the surface of the sample 235 and the sample stage, including using focal length estimation and / or ranging or profilometry techniques in the imaging mode of the SEM 205. Thus, the deposition process can include positioning the sample stage 125 in the vacuum chamber 120 such that the surface of the sample 130 (more generally, the ROI 230) at least partially coincides with the site. Positioning the sample stage 125 can include tilting the sample stage 125, as described in more detail with reference to Figure 1 such that the charged particle beam 220 is oriented at an angle “α” relative to the surface of the sample 235. The angle α can range from about 0 radians to about π radians, or about 0 degrees to about 180 degrees, where a value of about π / 2 radians or 90 degrees corresponds to substantially normal incidence of the charged particle beam 220 with the surface of the sample 235. In some cases, the value of the angle α can be selected at least partially based on the topography of the surface of the sample 235. For example, in the case where the sample 130 includes surface features such as sidewalls or other features oriented at a non-zero angle relative to the overall surface of the sample 235, the sample stage 125 can be oriented such that the angle α corresponds to substantially normal incidence of the charged particle beam 220 and the local surface of the feature.

[0043] In some embodiments, the angle α can be dynamic during the deposition process. Advantageously, the tilting stage can be used during the deposition process to form a substantially conformal coating in the ROI 230 that includes topographies that would otherwise create shadows. In some embodiments, portions of the sample 130 can be used to generate secondary electrons rather than directly irradiating the surface of the ROI 230. In this way, coating of hidden surfaces (e.g., outside the line of sight of the charged particle beam 220) can be facilitated by directing the charged particle beam 220 to locations around and / or within the ROI 230. To this end, for the SEM 205 and / or FIB 210, the charged particle beam 220 can be scanned across the surface of the sample 235 within and / or outside the ROI 230 according to the scan pattern 240. The scan pattern 240 can include linear translations across the surface of the sample 235, but can also include more complex patterns such as raster patterns, geometric patterns, and discontinuous patterns.

[0044] The charged particle beam 220 irradiates a portion of the surface of the sample 235 described by the spot size 241. To this end, the scan pattern 240 can be defined (e.g., as a time-dependent voltage signal or a signal generated to control the scan coils of the SEM 205) such that the beam spots at least partially overlap as the beam spots are rasterized or otherwise traversed across the surface of the sample 235. The overlap percentage of the scan pattern 240 can be used to manipulate the average energy provided to the sample surface and the local secondary electron emission, and the overlap percentage can be determined at least in part based on the spot size 241 and the geometric aspects of the scan pattern 240. Advantageously, this provides multiple control parameters to improve the quality of the deposited material layer 245.

[0045] As described in more detail with reference to the subsequent figures, the size, composition, spatial characteristics, surface properties, chemical properties, and physical properties of the deposited material layer 245 can be affected by selecting a set of operating parameters of the exemplary system 200. For example, the composition of the gas flow 225, the distance between the GIS nozzle 119 and the surface of the sample 235, and the volumetric flow rate of the gas flow 225 can independently affect the concentration of precursors near the surface of the sample 235 and / or the equilibrium surface coverage θ of the precursors on the surface. Since the equilibrium surface coverage θ also depends on environmental factors including the local temperature of the surface in the ROI 230, the pressure in the vacuum chamber 120, and the composition of the sample 130, beam-induced deposition can be adjusted by multiple variables that do not involve the operating parameters of the SEM 205 or FIB 210. Parameters regarding the SEM 205 and / or FIB 210, beam current, beam energy, spot size 241, dwell time, overlap percentage, and other aspects of the scan pattern 240 can be adjusted to affect some or all of the same material properties of the layer 245.

[0046] Figure 3is a block diagram illustrating an example process 300 for beam-induced deposition in accordance with some embodiments of the present disclosure. One or more operations of the example process 300 may be performed by a computer system in communication with additional systems including, but not limited to, a characterization system, a network infrastructure, a database, and a user interface device. In some embodiments, at least a subgroup of the operations Figure 3 described are performed automatically (e.g., without human intervention) or semi-automatically (e.g., initiated by a human and / or with limited human intervention). In one illustrative example, an analytical instrument system (e.g., Figure 1 example system 100) is used to perform the following operations: generate a gas stream (e.g., Figure 2 gas stream 225), direct the gas stream towards a region of interest on a sample (e.g., Figure 2 ROI 230), and irradiate a region of the sample.

[0047] At operation 305, the example process 300 includes directing a gas stream into a vacuum chamber. As described in more detail with reference to Figures 1 to 2 the vacuum chamber may be a component of a charged particle beam system (e.g., FIB, SEM, electron beam apparatus, dual beam apparatus, etc.). Operation 305 may include operations for flowing a carrier gas through a gas injection system (e.g., Figure 1 GIS115) and for introducing a gaseous or vapor precursor into the carrier gas. The carrier gas may be an inert gas (e.g., a noble gas) or a reactive gas (e.g., a halogen-containing gas). For example, the carrier gas may include an inert component and a reactive component. The carrier gas may include components that react with one or more fragments of the decomposed precursor and / or the precursor itself to form a material layer.

[0048] In some embodiments, the precursor has a vapor pressure greater than about 1.6×10 - 4Hydrocarbons in mbar. In some embodiments, the hydrocarbon comprises one or more compounds other than naphthalene. Since naphthalene is included in the Substance Priority List compiled and publicly available by the Agency for Toxic Substances and Disease Registry of the US Centers for Disease Control and Prevention in 2023, excluding naphthalene from the precursor reduces the environmental, health, and safety risks of the exemplary method 300. In some embodiments, the hydrocarbon comprises biphenyl. Biphenyl is not included in the same publicly available Substance Priority List in 2023. Biphenyl may be at least partially substituted. The substituents may include one or more of methyl, ethyl, propyl, butyl, amine, amide, acetyl, carboxyl, phosphine, ketone, ether, etc. In some embodiments, the biphenyl does not include polychlorinated biphenyls. The hydrocarbon may include at least partially substituted naphthalene. Substituted naphthalene includes one or more substituents characterized by reduced hazard and negligible or no reduction in performance as a deposition precursor. The hydrocarbon may include methane, ethylene, propane, styrene, camphor, menthol, benzoic acid, cyclohexane, cyclohexanone, cyanononane, acetone, methanol, nitromethane, acetonitrile, formic acid, acetic acid, propionic acid, acrylic acid, etc., which each provide reduced hazard compared to naphthalene in the beam-induced deposition of a carbon layer (e.g., Figure 2 the material layer 245).

[0049] Analysis of precursor performance in deposition using first principles of thermodynamics can be complicated by unknown sample composition, local variations in surface conditions, challenges associated with precise measurement of gas stream composition, etc. Thus, the performance improvement of a given precursor relative to naphthalene can be estimated by comparing the surface precursor behavior in an ideal system. In this way, the range of chemicals that can be used as carbon deposition precursors can be understood to include those precursors that achieve a substantially equal or greater equilibrium surface coverage θ relative to naphthalene under a given set of environmental conditions in a vacuum chamber and for a given sample, where θ is defined using a relevant adsorption isotherm model. Without being bound by a specific physical model or mechanism, it is understood that molecules having an affinity for a given surface will perform well as deposition precursors, where the volatility of the decomposition products and the chemical reactivity with the substrate do not mitigate this effect. In a complementary method, the precursor is characterized by having a substantially equal or greater surface mobility of adsorbed molecules under a given set of environmental conditions in a vacuum chamber and for a given sample. The effect of surface mobility can be understood as improving the flux of the adsorbed substance towards regions of low concentration, which is due to, for example, precursor depletion caused by beam-induced decomposition.

[0050] In some embodiments, operation 305 includes an operation for generating a vapor of a solid or liquid precursor by sublimation and / or vaporization. In an illustrative example, biphenyl can be sublimated under vacuum at a temperature in the range of about 273K to about 385K (including its sub-ranges, fractions, and interpolations). To this end, operation 305 may include sub-operations by which a reservoir of the precursor (e.g.,Figure 1 The heating element in thermal contact with the precursor reservoir 117 raises the temperature of the precursor from ambient temperature by about 10K, 20K, 30K, 40K, 50K, 60K, 70K, 80K, 90K, 100K, 110K or more (including fractions and interpolations thereof). Heating the precursor can increase the pressure of the precursor vapor in the GIS 115 such that the temperature of the precursor can be used to regulate the flow rate, the precursor flux at the sample surface, and / or the partial pressure of the precursor gas flow, and to control the consumption of the precursor near the sample surface. To this end, heating at temperatures below about 273K may result in deposition with limited consumption, while heating at temperatures above about 385K may introduce excessive precursor into the chamber, thereby creating a risk of contaminating the charged particle beam column and / or vacuum chamber components due to deposition on the chamber and column surfaces.

[0051] At operation 310, example process 300 includes irradiating an area of the sample surface. As described in more detail with reference to Figures 1 to 2 Operation 310 can include radiation by a charged particle beam and / or a photon beam. In some embodiments, operation 310 includes sub-operations for generating an ion beam and directing the ion beam towards a site defined in the vacuum chamber of the charged particle beam system. As described in more detail with reference to Figure 2 The site can be defined by the intersection of the beam axes (e.g., Figure 1 beam axes A and B) in a dual-beam system, but can also be defined by the intersection of the flow path of the GIS system with the beam axis of the charged particle source where the sample is located. Irradiating the area can include generating a charged particle beam with a beam energy in the range of about 1keV to about 50keV (including sub-ranges, fractions, and interpolations thereof). Irradiating the area can include directing a current density of about 0.1pA / μm 2 to about 300pA / μm 2 (including sub-ranges, interpolations, and fractions thereof) to a surface located substantially at the site. As described in more detail with reference to Figures 5A to 6C The volumetric yield of the deposited material can be effectively controlled by adjusting the current density. The current density can in turn be adjusted using beam parameters, including beam current, the size of the scan pattern, and spot size.

[0052] The operations of example process 300 are presented in an exemplary order, but one or more operations can be reordered, repeated, omitted, and / or parallelized. Additionally, additional and / or alternative operations can be included as part of example process 300, and some operations before and / or after those described with reference to Figure 3 can form part of the processing workflow. For example, the operations of example process 300 can be performed in conjunction with using an FIB (e.g., Figure 2After one or more operations to remove at least a portion of the sample by the FIB 210), and may be before one or more operations such as extracting a portion of the sample using TEM for further microanalysis. Also, for example, SEM imaging operations can be implemented during the execution of the operations of the exemplary process 300. To this end, in some embodiments, the exemplary process 300 includes an operation for beam-induced deposition, which can form part of a larger sample preparation procedure.

[0053] Example 1 - Ion Beam Induced Deposition

[0054] Figure 4A is an electron micrograph of an exemplary sample surface prepared according to some embodiments of the present disclosure, on which a carbon-containing material has been deposited using a biphenyl precursor. The micrograph shows that the biphenyl precursor can be used to deposit a substantially conformal coating on the surface region that has been irradiated with an ion beam. In Figure 4A this case, the surface is irradiated using a scanning pattern to reproduce the word "biphenyl" in a rectangular frame. The volumetric properties of the deposition are illustrated in Figure 4B in.

[0055] Figure 4B is prepared according to some embodiments of the present disclosure Figure 4A is an electron micrograph of a partial front view of an exemplary carbon-containing material. As shown, the deposition is located and retained in the irradiated area, while also producing a substantially uniform deposition height. This deposition height can in turn be controlled using beam and / or gas flow parameters, as demonstrated by the raised and recessed areas of the frame. When the text presents a substantially uniform height, the four areas of the frame are recessed relative to the text.

[0056] Figure 4C is an electron micrograph of an exemplary sample surface prepared according to some embodiments of the present disclosure, on which a carbon-containing material has been deposited using an acrylic precursor. Similar to the images in Figure 4A and Figure 4B the acrylic precursor is shown to form a local deposition corresponding to the ion beam irradiation.

[0057] Figures 5A to 5BIt is a data graph showing the influence of the operating parameters of an exemplary charged particle beam system according to an embodiment of the present disclosure on the performance of beam-induced deposition using a biphenyl precursor. In each graph, the horizontal x-axis depicts the current density as the independent variable, while the vertical y-axis depicts the volume yield as the dependent variable. The volume yield describes the volume of deposited material per unit charge and is a useful metric for measuring the effectiveness of precursor deposition material. Advantageously, the biphenyl precursor used in these experiments did not exhibit the same environmental, health, or safety risks as those presented by continuous use of naphthalene, while still performing well as a deposition precursor in both liquid metal and gas ion sources. As described in more detail with reference to Embodiment 2 below.

[0058] In Figure 5A , data for three operating conditions are given. The first set of data is marked with circles "○" and corresponds to deposition using a Xe + ion beam at 5 keV and 1 nA. The second set of data is marked with diamonds "◇" and corresponds to deposition using a Xe + ion beam at 12 keV and 1 nA. The third set of data is marked with triangles "Δ" and corresponds to deposition using a Xe + ion beam at 12 keV and 70 nA. Figure 5A It shows that each operating condition produced a measurable volume yield of the deposited carbon-containing layer. The volume yield increased at lower beam energy values of 5 keV and tended to decrease at higher current densities for all beam energy and beam current values.

[0059] In Figure 5B , for a single beam energy of 30 keV using Ga + ions, the relative influence of the beam current is illustrated in a set of data generated using three different beam current values of 77 pA ("○"), 0.77 nA ("◇"), and 8.9 nA ("Δ"). Increasing the current beyond about 1 nA seems to have an adverse effect on the volume yield. Similar to the trend observed in Figure 5A , the current density and the volume yield seem to be negatively correlated.

[0060] In Figure 5C , for two different currents of 1 nA ("◇") and 70 nA ("Δ") using Xe + ions, the influence of the current density on the vertical growth rate is illustrated in a set of data generated using two different beam energy values of 5 keV ("○") and 12 keV. Increasing the current density beyond about 100 pA / μm 2 seems to have an adverse effect on the rate. Different from the previous data, Figure 5CThe data indicate a direct correlation between the growth rate and the current density, which exhibits a decreasing growth with increasing current density. For different beam energy values, the growth rate appears to be consistent and relatively insensitive to the beam current, with a growth rate reduction of approximately 20% observed between a current of 1 nA and 70 nA. Advantageously, the current behavior indicates that biphenyl is a suitable precursor for carbon deposition under a wide range of operating conditions, including plasma - FIB gas ion sources.

[0061] In Figure 5D a set of data generated using Ga + ions with a beam energy of 30 keV and three different beam currents 77 pA nA (“○”), 0.77 nA (“◇”), and 8.9 nA (“Δ”), the effect of current density on the vertical growth rate is illustrated. Similar to Figure 5C the data, Figure 5D the data indicate a direct correlation between the growth rate and the current density, which exhibits a decreasing growth with increasing current density. The growth rate appears to be relatively insensitive to the beam current, with a growth rate reduction of approximately 40% observed in the range greater than 0.077 nA to 100 times the lower limit of 8.9 nA. Advantageously, the current behavior indicates that biphenyl is a suitable precursor for carbon deposition under a wide range of operating conditions, including in a liquid metal ion source.

[0062] Figures 6A to 6B is a data plot illustrating the effect of the operating parameters of an exemplary charged particle beam system according to an embodiment of the present disclosure on the performance of beam - induced deposition using an acrylic precursor. In each plot, the horizontal x - axis depicts the current density as the independent variable, while the vertical y - axis depicts the volume yield as the dependent variable. The volume yield describes the volume of deposited material per unit charge and is a useful metric for measuring the effectiveness of precursor deposition material. Advantageously, the acrylic precursor used in these trials does not exhibit the same environmental, health, or safety risks presented by the continuous use of naphthalene, while still performing well as a deposition precursor.

[0063] In Figure 6A a set of data generated using Xe + ions with a current of 1 nA, the relative effect of beam energy is illustrated in a set of data generated using three different beam energy values 5 keV (“○”), 12 keV (“□” and “Δ”), and 30 keV (“◇”). Increasing the current density beyond approximately 10 pA / μm 2 appears to have an adverse effect on the volume yield. Similar to the trend observed in Figures 5A to 5B , the current density and the volume yield appear to be negatively correlated. Advantageously, Figure 6A the data show that acrylic performs well at relatively low current densities (e.g., below approximately 10 pA / μm 2) is a suitable carbon deposition precursor that allows deposition to be carried out with a relatively low risk of damage to the sample by the charged particle beam.

[0064] In Figure 6B , among a set of data generated using a beam energy of 30 keV (“○”) and a current of 0.8 nA of Ga + ions, the relative effect of the beam energy is illustrated. Similar to the trends observed in Figures 5A to 5B and Figure 6A , the current density and the volume yield appear to be negatively correlated. Advantageously, Figure 6B the data shows that acrylic acid is a suitable carbon deposition precursor for a liquid metal ion source that allows deposition to be carried out with a relatively low risk of damage to the sample by the charged particle beam. 2 )

[0065] In Figure 6C , among a set of data generated using a beam energy of 30 keV (“◇”) and a current of 0.8 nA of Ga + ions, the effect of the current density on the vertical growth rate is illustrated. Increasing the current density beyond about 100 pA / μm 2 appears to have an adverse effect on the vertical growth rate. Different from the previous data, Figure 6C the data shows a non-linear relationship between the growth rate and the current density that is related to a threshold density beyond which material deposition may degrade due to excessive ion flux. When observed in the context of the data in Figure 6B , these data support Figure 6B the volume yield in and the results using acrylic acid as the carbon deposition precursor.

[0066] In Figure 6D , for Xe + ions with a beam current of 1 nA, the effect of the current density on the vertical growth rate is illustrated among a set of data generated using three different beam energy values of 5 keV (“Δ”), 12 keV (“○” and “□”), and 30 keV (“◇”). Similar to the trends observed in Figures 5C to 5D , Figure 6D the data shows a direct correlation between the growth rate and the current density for beam energy values below about 15 keV, which exhibits a decreasing growth with increasing current density. However, for the data collected at 30 keV, an inverse correlation is observed. Except for the data at 30 keV, the growth rate appears to be consistent for different beam energy values. These data support Figure 6A the volume yield and the results using acrylic acid as the carbon deposition precursor at beam energies below about 30 keV.

[0067] Example 2 - Deposition Improved Relative to Naphthalene

[0068] Figures 7A to 7C It is a data graph exemplifying comparative data generated in electron beam induced deposition using a biphenyl precursor and a naphthalene precursor by using an example charged particle beam system according to an embodiment of the present disclosure. In each graph, the horizontal x-axis describes the pattern time as an independent variable in seconds, and the vertical y-axis describes the vertical height as a dependent variable in micrometers (μm). The pattern time describes the duration for which the sample is irradiated with a charged particle beam in the presence of the precursor and can be used as an input parameter for adjusting the charged particle dose.

[0069] Figure 7A It exemplifies comparative data of electron beam induced deposition of carbon-containing materials from a biphenyl precursor shown as solid circles (“●”) and a naphthalene precursor shown as hollow circles (“○”). In the experiment for generating the data, the primary electron beam had an energy of about 1 kilo-electron volt (keV) and a beam current of about 2000 picoamperes. In terms of height as a function of pattern time, biphenyl performs better than naphthalene as a precursor. Advantageously, the relatively rapid deposition of material from the biphenyl precursor as a function of pattern time allows for the formation of a material of comparable thickness in a relatively short time, thereby reducing the electron dose and preparation time of the sample, each representing an improvement in the performance of the overall sample preparation process.

[0070] Figures 7B to 7C It exemplifies comparative data of electron beam induced deposition of carbon-containing materials from a biphenyl precursor shown as solid circles (“●”) and a naphthalene precursor shown as hollow circles (“○”). In the experiment for generating the data, Figure 7B the primary electron beam in [[]] had an energy of about 2 keV and a beam current of about 2000 picoamperes. Figure 7C the primary electron beam in [[]] had an energy of about 5 keV and a beam current of about 2000 picoamperes.

[0071] As Figure 7A shown in the data of [[]], the experiments at relatively high beam energies show that, in terms of height as a function of pattern time, biphenyl performs better than naphthalene as a precursor. Advantageously, the relatively rapid deposition of material from the biphenyl precursor as a function of pattern time allows for the formation of a material of comparable thickness in a relatively short time, thereby reducing the electron dose and preparation time of the sample, each representing an improvement in the performance of the overall sample preparation process.

[0072] Figures 8A to 8B It is a data graph exemplifying comparative data generated in gallium ion beam induced deposition using a biphenyl precursor and a naphthalene precursor by using an example charged particle beam system according to an embodiment of the present disclosure. In each graph, the horizontal x-axis describes the current density as an independent variable. In [[]] Figure 8AIn [reference], the vertical y-axis describes the vertical rate as the dependent variable in units of micrometers per minute (μm / min). In Figure 8B In [reference], the vertical axis describes the volume yield, which is a measure of the volume of deposited material per unit charge and is a useful measure for gauging the effectiveness of the precursor deposition material.

[0073] Figure 8A Illustrates comparative data for the deposition of ion beam-induced carbon-containing materials from a biphenyl precursor shown as solid circles (“●”) and a naphthalene precursor shown as open circles (“○”). In the experiment that generated the data, the primary ion beam had an energy of approximately 30 kiloelectron volts (keV) and a beam current of approximately 770 picoamperes. In terms of the deposition rate as a function of current density, biphenyl performed better as a precursor than naphthalene. Advantageously, as a function of the dose per unit surface area, the relatively rapid deposition of material from the biphenyl precursor allows for the formation of a material of comparable thickness in a relatively short time, thereby reducing the ion dose and preparation time of the sample, each representing an improvement in the performance of the overall sample preparation process.

[0074] Figure 8B Illustrates comparative data for the deposition of ion beam-induced carbon-containing materials from a biphenyl precursor shown as solid circles (“●”) and a naphthalene precursor shown as open circles (“○”). In the experiment that generated the data, Figure 8B the primary ion beam in [reference] had an energy of approximately 30 keV and a beam current of approximately 770 picoamperes. As shown in the data of Figure 8A the data in Figure 8B show that biphenyl performed better as a precursor than naphthalene, having a relatively high volume yield at each current density value. Advantageously, for a given current density, the relatively high material yield from the biphenyl precursor allows for the formation of a material of comparable volume in a relatively short time, thereby reducing the electron dose and preparation time of the sample, each representing an improvement in the performance of the overall sample preparation process.

[0075] Figures 9A to 9B is a data plot illustrating comparative data generated in xenon ion beam-induced deposition using a biphenyl precursor and a naphthalene precursor under various operating conditions using an exemplary charged particle beam system according to embodiments of the present disclosure. In each plot, the horizontal x-axis describes the current density as the independent variable in units of seconds. In Figure 9A In [reference], the vertical y-axis describes the vertical rate as the dependent variable in units of micrometers per minute (μm / min). In Figure 9B In [reference], the vertical axis describes the volume yield. In the experiment that generated the data, the primary ion beam had an energy of approximately 12 keV and a beam current of approximately 1000 picoamperes.

[0076] Figure 9AIllustrates comparative data for the deposition of carbon-containing materials induced by a xenon ion beam from a biphenyl precursor shown as a solid circle (“●”) and a naphthalene precursor shown as an open circle (“○”). In terms of deposition rate as a function of current density, biphenyl performs better as a precursor than naphthalene. Similarly, Figure 9B Illustrates comparative data for the deposition of carbon-containing materials induced by a xenon ion beam from a biphenyl precursor shown as a solid circle (“●”) and a naphthalene precursor shown as an open circle (“○”). As Figure 9A shown in the data of Figure 9B the data in

[0077] Figures 10A to 10C show that biphenyl performs better as a precursor than naphthalene, with a relatively high volumetric yield at each current density value. Advantageously, for a given current density, the relatively high material yield from the biphenyl precursor allows for the formation of a comparable volume of material in a relatively short time, thereby reducing the ion dose and preparation time of the sample, each representing an improvement in the performance of the overall sample preparation process. Figures 10A to 10C reproduces Figures 8A to 8B the findings of Figures 10A to 10C for gallium ion beams with energies of approximately 2 keV, 5 keV, and 30 keV and beam currents of 340 picoamperes, 690 picoamperes, and 770 picoamperes, respectively. As in the previous figure, the data for the biphenyl precursor are shown as solid circles (“●”), and the data for the naphthalene precursor are shown as open circles (“○”). Advantageously,

[0078] Figures 11A to 11C is a data graph illustrating comparative data generated by an exemplary charged particle beam system in argon ion beam-induced deposition using biphenyl and naphthalene precursors according to an embodiment of the present disclosure. In each graph, the horizontal x-axis depicts the patterning time as the independent variable in seconds, and the vertical y-axis depicts the vertical height as the dependent variable in micrometers (μm).

[0079] Figures 11A to 11C reproduces Figures 7A to 7C and Figures 10A to 10C the findings of Figures 11A to 11CThe data in [ ] show that biphenyl performs better than naphthalene as a deposition precursor for ion beam induced deposition and electron beam induced deposition within a relatively wide operating window. Additionally, Figures 11A to 11C show that biphenyl performs well as a deposition precursor for various inert gas ion sources and metal ion sources.

[0080] In the foregoing description, various embodiments have been described. For purposes of explanation, specific configurations and details have been set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to those skilled in the art that the embodiments may be practiced without these specific details. In addition, well-known features may have been omitted or simplified in order not to obscure the described embodiments. While the example embodiments described herein are centered around charged particle beam systems and particularly ion beam systems, these are meant to be non-limiting illustrative embodiments. The embodiments of the present disclosure are not limited to such embodiments, but are intended to address analytical instrument systems for which various material samples can be processed to prepare samples for further microanalysis of chemical, biological, physical, structural, or other properties, and other aspects, including but not limited to phase structure, trace element composition, and the like.

[0081] Some embodiments of the present disclosure include a system having one or more data processors and / or logic circuits. In some embodiments, the system includes a non-transitory computer-readable storage medium containing instructions that, when executed on the one or more data processors and / or logic circuits, cause the one or more data processors and / or logic circuits to perform some or all of one or more of the methods disclosed herein and / or some or all of one or more processes and workflows. Some embodiments of the present disclosure include a computer program product tangibly embodied in a non-transitory machine-readable storage medium, the computer program product including instructions configured to cause one or more data processors and / or logic circuits to perform some or all of one or more of the methods disclosed herein and / or some or all of one or more processes.

[0082] The terms and expressions employed herein are used as descriptive terms and not of limitation, and in using such terms and expressions, there is no intention to exclude any equivalents of the features shown and described or portions thereof, but it should be recognized that various modifications are possible within the scope of the claims. Accordingly, it should be understood that while the present disclosure includes specific embodiments and optional features, those skilled in the art may make modifications and variations to the concepts disclosed herein, and such modifications and variations are considered to be within the scope of the appended claims.

[0083] When a term is used without an express definition, it should be understood that unless the term has a special and / or specific meaning in the field of charged particle microscopy systems or other relevant fields, the term refers to the ordinary meaning of the word. The terms "about" or "substantially" are used to denote a deviation from the stated property, where the deviation has little or no effect on the corresponding function, property, or attribute of the described structure. In an illustrated example where one dimensional parameter is described as "substantially equal" to another dimensional parameter, the term "substantially" is intended to reflect that the two parameters being compared may be unequal within an admissible limit (such as manufacturing tolerances or the confidence interval inherent in system operation). Similarly, in cases where a geometric parameter (such as alignment or angular orientation) is described as "about" perpendicular, "substantially" perpendicular, or "substantially" parallel, the terms "about" or "substantially" are intended to reflect that the alignment or angular orientation may differ from the precisely stated condition within an admissible limit (e.g., not precisely perpendicular). For dimensional values (such as diameter, length, width, etc.), the term "about" may be understood to describe a deviation of up to ±10% from the stated value. For example, a dimension of "about 10 mm" may describe a dimension ranging from 9 mm to 11 mm.

[0084] This description provides exemplary embodiments and is not intended to limit the scope, applicability, or configuration of the present disclosure. Instead, the subsequent description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing various embodiments. It should be understood that various changes may be made to the function and arrangement of the elements without departing from the spirit and scope set forth in the appended claims. Specific details are given in the description to provide a thorough understanding of the embodiments. However, it should be understood that the embodiments may be practiced without these specific details. For example, specific system components, systems, processes, and other elements of the present disclosure may be shown in schematic form or omitted from the illustrations to avoid obscuring the embodiments with unnecessary details. In other instances, well-known circuits, processes, components, structures, and / or techniques may be shown without unnecessary details.

Claims

1. A charged particle beam system, comprising: Vacuum chamber; a charged particle beam source operably coupled to the vacuum chamber and comprising an emitter section and a column section, the charged particle beam source being configured to generate a charged particle beam and direct the charged particle beam into the vacuum chamber; and a precursor source operably coupled to the vacuum chamber and configured to direct a flow of a gas containing a precursor into the vacuum chamber, wherein the precursor comprises a vapor pressure greater than about 1.6×10 -4 mbar of hydrocarbons, and wherein the hydrocarbons are not naphthalene.

2. The system of claim 1, wherein the hydrocarbon is not included in a priority list of substances compiled by the Agency for Toxic Substances and Disease Registry of the Centers for Disease Control and publicly available as of 2023.

3. The system of claim 1, wherein the hydrocarbon comprises biphenyl.

4. The system of claim 3, wherein the biphenyl comprises one or more substituents selected from the group consisting of methyl, ethyl, propyl, butyl, amine, amide, acetyl, carboxyl, phosphine, ketone, and ether.

5. The system of claim 1, wherein the hydrocarbon comprises a substituted naphthalene.

6. The system of claim 1, wherein the hydrocarbon is selected from the group consisting of methane, ethylene, propane, styrene, camphor, menthol, benzoic acid, cyclohexane, cyclohexanone, cyanononane, acetone, methanol, nitromethane, acetonitrile, formic acid, acetic acid, propionic acid, and acrylic acid.

7. The system of claim 1, wherein under a given set of environmental conditions in the vacuum chamber and for a given sample, the precursor achieves an equilibrium surface coverage θ that is substantially equal to or greater than naphthalene, wherein θ is defined using a relevant adsorption isotherm model.

8. The system of claim 1, wherein the precursor is characterized by having an adsorbed molecular surface mobility substantially equal to or greater than naphthalene under a given set of environmental conditions in the vacuum chamber and for a given sample.

9. The system of claim 1, further comprising a sample stage disposed in the vacuum chamber and defining a location in the vacuum chamber such that the charged particle beam source and the precursor source are configured to direct the charged particle beam and the gas flow, respectively, toward the location.

10. The system of claim 1, further comprising: a control circuit operatively coupled to the charged particle beam source and the precursor source; and one or more non-transitory machine-readable storage media operably coupled to the control circuitry and storing instructions that, when executed by the system, cause the system to perform operations including: directing the gas flow into the vacuum chamber toward a defined location in the vacuum chamber; and An area including the site is irradiated using the charged particle beam.

11. The system of claim 10, wherein irradiating the area comprises irradiating about 0.1 pA / μm 2 To about 300pA / μm 2 The current density is directed onto the surface substantially at the site.

12. The system of claim 10, wherein the operations further comprise heating the precursor at a temperature of about 273K to about 385K.

13. A method for generating a carbonaceous material in a charged particle beam system, the method comprising: directing a gas stream into a vacuum chamber of the charged particle beam system, the gas stream comprising a precursor, wherein the precursor comprises a vapor pressure greater than about 1.6×10 -4 mbar of hydrocarbons, and wherein the hydrocarbons are not naphthalene; and An area of ​​the sample is irradiated using a charged particle beam.

14. The method of claim 13, wherein the hydrocarbon is biphenyl.

15. The method of claim 14, wherein the biphenyl comprises one or more substituents selected from the group consisting of methyl, ethyl, propyl, butyl, amine, amide, acetyl, carboxyl, phosphine, ketone, and ether.

16. The method of claim 13, wherein the charged particle beam comprises argon ions, xenon ions, or gallium ions. The method of claim 13 , wherein the charged particle beam comprises electrons.

18. The method of claim 13, wherein the charged particle beam has a charge current of about 0.1 pA / μm 2 To about 300pA / μm 2 of current density.

19. The method of claim 13, wherein the charged particle beam has a beam energy of about 1 keV to about 50 keV.

20. The method of claim 13, further comprising heating the precursor to a temperature of about 273K to about 385K.

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