Charged Particle Beam Source

Abstract

To provide a charged particle beam source, e.g., for use in an electron microscope.SOLUTION: A charged particle beam source, e.g., for use in an electron microscope, can include an electrically conductive support member coupled to a base, a mounting member being coupled to the support member and defining a bore, and an emitter member received in the bore and retained by a fixative material layer flowed around the emitter member in the bore.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to charged particle beam sources, such as electron beam sources, and systems and methods for manufacturing same. [Background technology]

[0002] Charged particle beam (CPB) sources, such as those used in scanning and / or transmission electron microscopes, typically include a beam-generating element, such as a filament, that emits a beam of charged particles when electrically biased and / or thermally heated (e.g., in the case of a Schottky emitter). Such filaments are typically made from metallic materials, such as crystalline tungsten or rhenium, compound materials, such as lanthanum hexabromide (LaB6) or cesium hexabromide (CeB6), and / or other materials with low work functions. However, coupling a filament made of a low work function compound material to a heating element, such as a tungsten hairpin, can be problematic, as these materials typically cannot be attached by electrical spot welding. Thus, existing CPB sources made from compound materials typically rely on the application of a compressive force to the emitter filament by part of the heating element structure, such as by frictional engagement or clamping the filament between graphite sheets in a Vogel mount. Other approaches include fixing the filament by focused ion beam (FIB) welding when the emitter filament has a thickness of nanometers to micrometers. In each of these approaches, precise alignment of the emitter filament is difficult and time consuming. Vogel mounts also typically require relatively high electrical heating currents to clean the emitter and / or to initiate beam generation during source operation, which can, for example, cause thermal stability problems. FIB welding is time consuming, technically complex, and typically must be performed under vacuum, resulting in relatively high manufacturing costs and low productivity. Thus, there is a need for improved CPB source structures and manufacturing techniques. Summary of the Invention

[0003] Certain embodiments of the present disclosure relate to a charged particle beam source or module for use in a charged particle beam system such as an electron microscope. In an exemplary embodiment, the charged particle beam source may include a conductive support member coupled to a base, a mounting member coupled to the support member and defining a bore, and an emitter member received within the bore and retained by a layer of stationary material flowed around the emitter member.

[0004] In any or all of the disclosed embodiments, the mounting member defines a longitudinal axis and the bore extends along the longitudinal axis.

[0005] In any or all of the disclosed embodiments, the mounting member includes an opening along the length of the mounting member that is longitudinally offset from a free end of the mounting member, the opening communicating with the bore, and fastening material of the fastening material layer is received within the opening.

[0006] In any or all of the disclosed embodiments, the opening is a channel formed in the mounting member.

[0007] In any or all of the disclosed embodiments, the mounting member includes a plurality of channels spaced along its length and a plurality of retention portions extending around the emitter member.

[0008] In any or all of the disclosed embodiments, the mounting member includes a first end coupled to the support member, the free end being a free second end, and the opening being offset from the free second end toward the first end.

[0009] In any or all of the disclosed embodiments, the emitter member includes lanthanum hexabromide (LaB6) or cesium hexabromide (CeB6), or other emitter material that is not spot weldable.

[0010] In any or all of the disclosed embodiments, the layer of immobilizing material is formed from the dispersed phase of a colloidal liquid.

[0011] In any or all of the disclosed embodiments, the anchoring material layer includes graphite.

[0012] In any or all of the disclosed embodiments, the charged particle beam source is configured as an electron beam source.

[0013] In any or all of the disclosed embodiments, the emitter member is not clamped by other components of the charged particle beam source.

[0014] In another exemplary embodiment, a scanning electron microscope may include any or all of the charged particle beam sources of the disclosed embodiments.

[0015] In another exemplary embodiment, a method of making a charged particle beam source includes forming a bore in a mounting member, inserting an emitter member into the bore of the mounting member, and flowing a colloidal liquid around the emitter member and the mounting member to form a layer of immobilized material.

[0016] In another exemplary embodiment, a method of using a charged particle beam source includes heating an emitter member to generate a charged particle beam and directing the charged particle beam toward a target.

[0017] In another representative embodiment, a charged particle beam source comprises a conductive support member coupled to a base, a mounting member coupled to the support member and defining a bore, and an emitter member received within the bore, the mounting member comprising a retaining portion extending around the emitter member.

[0018] In any or all of the disclosed embodiments, the emitter member is retained within the bore by a layer of anchoring material that is flowed around the emitter member within the bore.

[0019] In any or all of the disclosed embodiments, the layer of immobilizing material is formed from the dispersed phase of a colloidal liquid.

[0020] In any or all of the disclosed embodiments, the charged particle beam source may further comprise a channel defined between the retaining portions.

[0021] In any or all of the disclosed embodiments, the bore and the emitter member each include a rectangular cross-section.

[0022] In another exemplary embodiment, a charged particle beam source includes an electrically conductive support member coupled to a base, a mounting member coupled to the support member and defining a bore, and an emitter member received in the bore and retained within the bore by a layer of fastener material, the bore having a cross-section larger than a cross-section of the emitter member.

[0023] In any or all of the disclosed embodiments, the emitter member is not clamped by the mounting member.

[0024] The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent with reference to the following detailed description and accompanying drawings. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic diagram of an exemplary embodiment of a charged particle beam system, in accordance with one embodiment. [Diagram 2] FIG. 2 is a side view of a charged particle beam source, according to one embodiment. [Diagram 3] FIG. 3 is an enlarged perspective view of the mounting member and emitter member of the charged particle beam source of FIG. 2. [Figure 4] 3 is a side view of the mounting member of FIG. 2 prior to forming the bores and channels. [Diagram 5]3 is an enlarged perspective view of a free end of the mounting member of FIG. 2 after forming the axial bore and the axially spaced channels according to one embodiment. [Figure 6] 3 is an enlarged perspective view of the free end of the mounting member of FIG. 2 showing the emitter member received within the axial bore; FIG. [Figure 7] 3 is an enlarged perspective view of the free end of the mounting member of FIG. 2, showing a layer of fastening material applied to secure the emitter member within the bore. FIG. [Figure 8] 3 is a perspective view of the free end of the mounting member and the emitter member of FIG. 2 prior to molding of the emitter member. [Figure 9] 3 is an enlarged perspective view of the free end of the mounting member and emitter member of FIG. 2, showing the emitter member configured as a cold field emitter, according to one embodiment. [Figure 10] 10 is an enlarged perspective view of a portion of the emitter member of FIG. 9. [Figure 11] 3 is a schematic diagram showing a cross-section of the emitter member of FIG. 2 superimposed on a cross-section of a bore of a mounting member. [Figure 12] 3 is a cross-sectional view of the charged particle beam source of FIG. 2 mounted within a portion of a charged particle microscope, according to one embodiment. [Figure 13] FIG. 1 is a process flow diagram illustrating a method of making a charged particle beam source, according to one embodiment. [Figure 14] 3 is an enlarged perspective view of a free end of the mounting member of FIG. 2, the free end comprising two channels circumferentially offset from one another; FIG. [Figure 15] 3 is an enlarged perspective view of a free end of the mounting member of FIG. 2, including a single channel. [Figure 16] 3 is an enlarged perspective view of a free end of the mounting member of FIG. 2, including a plurality of circular openings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The present disclosure relates to embodiments of charged particle beam (CPB) sources, such as electron beam sources, field emitters, electron guns, and the like, as well as systems and methods for their manufacture. The CPB sources disclosed herein are described in the context of CPB systems, such as CPB microscopes, but may also be useful in other applications, such as electron holography, x-ray sources, flat panel displays, and jet propulsion. The CPB sources described herein may include a conductive (e.g., metal) support member, such as a tungsten hairpin coupled to a pair of electrodes, and a metal (e.g., tungsten) mounting member coupled to and extending from an apex of the support member. The mounting member may define an axial bore in which an emitter member, such as a LaB6 or CeB6 filament, is received. The mounting member may further define at least one opening, aperture, or channel on a side of the mounting member and axially offset from a free end of the mounting member. The emitter member may be held within the bore of the mounting member by a layer of fastening material that flows around the mounting member and through at least one channel into the bore such that the inner surface of the bore, the corresponding surface of the emitter member, and / or the outer surface of the mounting member are coated with the layer of fastening material. The CPB sources disclosed herein may provide improved alignment of the beam generating emitter with the optical axis of the CPB system, as well as long-term stable and reliable operation at high temperatures, without significant degradation and without the need to clamp or hold the emitter in place with compressive forces applied by other elements of the structure.

[0027] Example 1 FIG. 1 illustrates an exemplary embodiment of a charged particle beam (CPB) system 100 comprising a beam column 102. The beam column 102 may be a charged particle microscope, such as, for example, a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a combination scanning and transmission electron microscope (STEM). In an exemplary embodiment, for ease of reference, but not by way of limitation, the beam column 102 is configured as a scanning electron microscope (SEM). The SEM 102 may comprise one or more CPB lenses, such as a condenser lens 116 and an objective lens 106. In some embodiments, the one or more CPB lenses may be magnetic lenses, and in particular, the objective lens 106 may be a magnetic objective lens. The SEM 102 is positioned to generate an image of a target or workpiece W.

[0028] The SEM 102 may be mounted to or within a vacuum chamber 108 that houses a positioning system 110 for holding and moving a workpiece W. The vacuum chamber 108 may be evacuated using a vacuum pump (not shown).

[0029] The SEM 102 may include a CPB source 112, which may be configured according to any of the embodiments of the CPB source described herein. The SEM 102 may be configured to manipulate the “raw” radiation beam from the CPB source 112 to perform operations on the radiation beam, such as focusing, aberration mitigation, cropping (using an aperture), filtering, scanning, etc. For example, the CPB source 112 may generate a beam of input charged particles (e.g., an electron beam) 114 propagating along a particle optical axis 115. The SEM 102 may generally include one or more lenses (e.g., a CPB lens), such as a focusing lens 116 and an objective lens 106, for focusing the beam 114 onto the workpiece W. In some embodiments, the SEM 102 may include a deflection unit 118, which may be configured to steer the beam 114. For example, the beam 114 may be steered in a scanning motion (e.g., a raster or vector scan) across a sample being investigated or a workpiece to be processed. In certain embodiments, additional CPB components such as other lenses, deflectors, stigmators, and / or apertures are used but are not shown for ease of illustration.

[0030] The CPB system 100 may further comprise a computer processor and / or controller 128 for controlling, among other things, the deflection unit 118, the charged particle beam (CPB) lenses 106, 116, the positioning system 110, and the detector (not shown), and for displaying information collected from the detector, such as images of the workpiece or portions thereof, position information, or system control data, on a display unit. In some cases, a control computer 130 is provided for establishing various excitations, recording image data, and generally controlling the operation of the SEM, the positioning system, etc.

[0031] Example 2 2 and 3 show a charged particle beam (CPB) source component, module, or assembly 200, according to one embodiment. CPB source 200 may include a base 201 that includes an insulating body 202 and two electrodes 204 and 206 disposed or embedded within insulating body 202. In certain embodiments, insulating body 202 may be made of a high temperature insulating material, such as any of a variety of ceramic materials (e.g., alumina, boron nitride, glass, machinable glass-ceramics, etc.).

[0032] The CPB source 200 may further comprise a curved or angled support member 208 (also referred to as a "hairpin") interconnecting the two electrodes 204 and 206 on one side of the insulating body 202. In an exemplary embodiment, the support member 208 may comprise a first portion 210 and a second portion 212 joined together at an apex 214. The first portion 210 of the support member 208 may be coupled or electrically connected to the electrode 204, and the second portion 212 of the support member may be coupled or electrically connected to the electrode 206. In certain examples, the first and second portions 210 and 212 may be coupled to opposite sides of the respective electrodes 204 and 206 (e.g., to points on the surface of the cylindrical electrodes offset 180° circumferentially) to align the apex 214 with the longitudinal axis (e.g., axis 218) of the insulating body 202. However, in other embodiments, portions 210 and 212 may be coupled to the same side of the electrode as each other, depending on the particular requirements of the system.

[0033] The CPB source 200 may further include a mounting member 216 coupled to and extending from the apex 214 of the support member 208. FIG. 3 shows the mounting member 216 in more detail. In the illustrated embodiment, the mounting member 216 is configured as a cylinder including a first end 220 coupled to the apex 214 of the support member 208 and a free second end 222, although in other embodiments the mounting member may have any shape. The mounting member 216 may define a longitudinal axis 218. The mounting member 216 may be separately formed and attached (e.g., by welding) to the support member 208 or may be integrally formed with the support member such that the support member and the mounting member are of unitary construction. As used herein, the terms "integrally formed" and "unitary construction" refer to a structure that does not include any welds, fasteners, or other means for fastening separately formed pieces of material to one another.

[0034] 5, the mounting member 216 may further comprise a shaft / lumen / cavity / bore 226 formed therein and extending from the free second end 222 in a direction along the longitudinal axis 218 (FIG. 3). For example, in the illustrated embodiment, the bore 226 includes an opening 228 at a free edge of the free second end 222 and may be configured to receive an emitter member or filament 224, as described further below. In certain embodiments, the bore 226 may extend along any portion of the length of the mounting member 216, depending, for example, on the length of the emitter member 224. In the illustrated embodiment, the bore 226 has a rectangular cross-section corresponding to the rectangular cross-section of the emitter member 224, although in other embodiments, the bore may have any cross-sectional shape, such as a round or circular cross-section, depending on the shape of the emitter.

[0035] In certain embodiments, the mounting member 216 may include one or more openings spaced along its length and configured as channels / recesses / trenches / slots 230. The channels 230 may be formed in the second end 222 of the mounting member 216 and may extend at least partially through a cross-section of the mounting member. With reference to FIGS. 3 and 5, the channels 230 may be in fluid communication with the bore 226 prior to application of the fastening material layer 242, described in more detail below. In certain embodiments, the channels 230 may extend perpendicular to the longitudinal axis 218 (FIG. 3) and may be axially spaced apart from one another along the length of the mounting member 216.

[0036] In certain embodiments, the channel 230 may be formed in the free second portion 222. For example, in the illustrated embodiment, the free second end 222 comprises two channels 230A and 230B axially spaced from one another along the longitudinal axis 218 and extending approximately to the middle of the thickness of the attachment member. The free second end 222 may further comprise curved protrusions or extensions configured as retaining members / portions 232 between successive channels 230 and / or disposed, in certain embodiments, on an end face of the free second end 222. For example, in the embodiment shown in FIG. 5, the attachment member 216 comprises a curved retaining portion 232A between the channels 230A and 230B and a curved retaining portion 232B located distal to the channel 230B. The bore 226 may extend through the retaining portions 232A and 232B.

[0037] 5, in the illustrated embodiment, the mounting member 216 may further include an extension or cradle portion 234 extending axially (e.g., distally) from the retaining portion 230B. The cradle portion 234 may define a longitudinally extending recess or channel 236 that is axially aligned with and in fluid communication with the bore 226 (at least prior to insertion of the emitter member 224 and application of the fixation material layer 242). In certain embodiments, the cradle portion 234 may include three axially extending pointed protrusions 248, 250, and 252 that together may define a notch 246.

[0038] In certain embodiments, the channels 230 may be circumferentially aligned with one another, as in the illustrated embodiment, or may be circumferentially offset. For example, in certain embodiments, the channels 230 may be formed anywhere around the circumference of the mounting member 216 and may have any angular spacing. For example, FIG. 14 shows another example in which channels 230A and 230B are circumferentially offset from one another by 180°. The channels 230 may also be formed with uniform axial spacing, as illustrated, or with different axial spacing between channels, depending on the particular requirements of the system. The channels 230 may also have any width measured axially and may extend around any percentage of the circumference of the mounting member. The channels also need not have the same width or circumferential length. In other embodiments, the mounting member may include only a single channel 230, as shown in FIG. 15. In still other embodiments, the channel 230 may be an opening or aperture of any size and / or shape in fluid communication with the bore 226 and may be formed in any number and at any location along and / or about the mounting member 216 to allow the fixative to enter the bore. For example, FIG. 16 shows a mounting member 216 including a plurality of round apertures 260, which may be angularly and longitudinally aligned with one another as shown, or may be angularly and / or longitudinally offset in any arrangement. The mounting member may also include multiple rows or bands of such apertures 260 axially spaced along the mounting member. In still other embodiments, the emitter member 224 may be received within the support member 208, for example, within a bore formed at the apex, and need not include a mounting member.

[0039] As noted above, the CPB source may further include an emitter member 224 coupled to the mounting member 216. More specifically, a base or first end 238 (FIG. 6) of the emitter member 224 may be received within a bore 226 of the mounting member 216, and the emitter member may extend axially from a free second end 222 of the mounting member in a direction along the longitudinal axis 218 (FIG. 3). In certain embodiments, the tip or free end of the emitter member 224 may be sharp or pointed. In the illustrated embodiment, the emitter member 224 has a rectangular cross-section corresponding to the rectangular bore 226, although the emitter member 224 and bore 226 may have any cross-sectional shape.

[0040] The emitter member 224 may be made of any of a variety of materials exhibiting a relatively low work function (e.g., 2.93 eV or less, such as 2.6 eV or less). Exemplary materials include crystalline lanthanum hexabromide (LaB6), cesium hexabromide (CeB6), crystalline tungsten (e.g., W(100)), ZrO-coated crystalline tungsten, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanocones, ZnO nanobelts, WOx nanowires, or other metal nanowires.

[0041] In certain embodiments, the emitter member 224 and the bore 226 have the same cross-sectional shape, but the cross-section (e.g., cross-sectional area) of the bore 226 may be larger than the cross-section (e.g., cross-sectional area) of the emitter member first end 238. This is illustrated in FIG. 11 , where the cross-section of the emitter member first end 238 is shown diagrammatically superimposed on the cross-section of the bore 226. Thus, prior to fastening or attaching the emitter member 224 to the mounting member 216, the emitter member may be free to move longitudinally within the bore 226 relative to the mounting member. Thus, unlike existing Vogel-type CPB sources, in the illustrated embodiment, the mounting member 216 does not clamp or apply a compressive force to the emitter member 224 to hold it in place.

[0042] Thus, a fastening material, bonding agent, or fastening or bonding means may be used to secure the emitter member 224 in place within the bore 226. In certain embodiments, the fastening material may be in the form of a layer of material that fastens / bonds / fastens / connects / attaches the emitter member 224 to the mounting member 216, referred to herein as fastening material layer 242 (FIGS. 3 and 7). In certain embodiments, the fastening material layer 242 may be a material that is applied in a liquid or flowable state, such as a colloidal liquid or the dispersed phase of a sol. In certain embodiments, the fastening material layer 242 may comprise a layer of graphite left after evaporation of the liquid phase or liquid medium of a colloidal graphite mixture. In certain embodiments, the fastening material layer 242 may extend at least partially around the periphery of the emitter member 224 within the bore 226 and / or around the outside of the mounting member 216 to bond or secure the emitter member 224 in place within the bore.

[0043] Exemplary materials that may be used to form the anchoring material layer 242 include graphite, graphene, buckyballs (e.g., C 60 ), carbon nanotubes, amorphous carbon, and the like. Such materials may be applied as part of a colloidal mixture (e.g., a dispersed phase) in which the liquid phase includes either water (e.g., an aqueous colloidal mixture), an alcohol (e.g., isopropanol), acetone, and the like. In other embodiments, the emitter member 224 may be fixed in place using other materials having relatively high melting temperatures, such as tungsten, rhenium, molybdenum, tantalum, and / or other processes including focused ion beam (FIB) welding, any of a variety of thin film deposition techniques, such as electron beam evaporation, thermal evaporation, sputtering, chemical vapor deposition, atomic layer deposition, and the like.

[0044] In certain embodiments, the support member 208 and / or the mounting member 216 may be made of any electrically conductive, high temperature material, such as any of a variety of metals having relatively high melting points. Non-limiting examples include tungsten (W) (e.g., polycrystalline tungsten), molybdenum (Mo), tantalum (Ta), rhenium (Re), niobium (Nb), and / or combinations or alloys of such metals.

[0045] 4-9 illustrate an exemplary process for fabricating a CPB source 200, according to one embodiment. FIG. 4 illustrates the mounting member 216 attached to the support member 208 in an unmachined state prior to forming the bores and channels. In certain embodiments, the free second end 222 of the mounting member 216 may include a pointed tip 244. In certain embodiments, the support member 208 and / or the insulating body 202 may be mounted in a suitable fixture, and the bores 226 may be formed by any of a variety of milling or micromachining techniques, such as, for example, laser beam machining, focused ion beam milling, etc. The channels 230 may be formed in a similar manner and / or by other techniques, including chemical etching (e.g., wet or dry etching), photolithography, etc.

[0046] FIG. 5 shows the mounting member 216 after forming the bore 226 and the channel 230. In an exemplary embodiment, a portion of the pointed tip 244 (FIG. 4) may be partially milled away to form the cradle portion 234 and the protrusions 248-252. In other embodiments, the pointed tip 244 may remain unmilled or may be milled away completely. Referring to FIG. 6, the emitter member 224 may then be inserted into the bore 226 in the direction of the arrow 254, for example, using a micromanipulator. Once received within the bore, the retaining portions 232A and 232B may extend around or over the emitter member 224 such that the emitter member is surrounded by the mounting member material at the retaining portions.

[0047] Referring to FIG. 7, the emitter member 224 may then be secured in place by applying a layer of securing material 242. In certain embodiments, the layer of securing material 242 may be applied in a liquid state (e.g., injected using a pipette), as in the case of colloidal graphite. The colloidal liquid may flow around and through the channel 230, into the bore 226 (FIG. 5) and around the emitter member 224, such that the emitter member 224 and the inner surface of the bore are wetted by the colloidal liquid along substantially the entire length of the bore 226. The liquid medium or liquid phase of the colloidal liquid may be allowed to evaporate, leaving behind a layer of securing material (e.g., a graphite layer) coating / covering / encapsulating / enveloping the surfaces of the emitter member, bore, and mounting member, holding the emitter member 224 in place. 7 and 8, the fastening material layer 242 may fill any gaps or cavities between the emitter member 224 and the oversized bore 226. In certain embodiments, the fastening material layer 242 and the mounting member 216 may bond / fuse / weld together at high temperatures to further help secure the emitter member 224 to the mounting member, such as in embodiments where the fastening material layer comprises carbon or graphite and the mounting member comprises tungsten. Such fusing or welding may occur during normal microscope operation and / or during a break-in period where the assembly is heated.

[0048] FIG. 8 illustrates emitter member 224 secured to mounting member 216. In certain embodiments, emitter member 224 may then undergo additional processing or shaping steps to operate as a cold field emitter, Schottky emitter, or the like. For example, in certain embodiments, emitter member 224 may be shortened to extend a specified distance beyond mounting member 216 (e.g., 200 μm in certain embodiments). In certain embodiments, the tip or free end of emitter member 224 may also be shaped / machined / milled to a point or other specified shape depending on the particular characteristics desired. For example, FIGS. 9 and 10 illustrate emitter members 224 configured as pyramids (FIG. 9) and nanorods (e.g., cylindrical or substantially cylindrical) (FIG. 10). Such emitters may be configured to operate as cold field emitters or Schottky emitters.

[0049] FIG. 12 shows a cross-sectional view of the CPB source 200 mounted in a charged particle microscope 300, which may be configured according to any of the CPB systems described herein. When mounted in the microscope 300, the emitter member 224 may be precisely aligned along the particle optical axis 302 of the microscope. By electrically biasing and / or heating the emitter member 224 (e.g., by passing a current through the support member 208) (depending on whether the emitter is configured as a cold field emitter or a Schottky emitter), the emitter member 224 may emit a beam of charged particles, which may be manipulated and focused by various elements of the beam column, as described above. In FIG. 12, only a portion of the second portion 212 of the support member 208, which is located behind the plane of the cross section, is visible.

[0050] One or more of the embodiments described herein may provide significant advantages over existing CPB sources. For example, inserting the emitter member into a bore in a mounting member and fixing the emitter member in place by flowing a fixing material into the bore allows for the manufacture of a significantly smaller CPB source than is possible using a conventional Vogel mount. The mounting member 216 of the CPB source described herein may be tens of micrometers or less in diameter, whereas a comparable Vogel mount may require a tungsten base mount or clamping member having a diameter or major dimension of hundreds of micrometers to several millimeters. Thus, the beam generating portion of a CPB source configured as described herein may be ten times smaller than a comparable CPB source including a Vogel mount. This may also reduce the current required to heat the emitter filament to an operating temperature, resulting in a corresponding increase in thermal stability.

[0051] Additionally, the time required to manufacture the CPB sources described herein may be significantly reduced as compared to existing sources while providing comparable or superior performance. More specifically, because the bore 226 may be formed in precise alignment with the axis of the mounting member 216, the emitter member 224 may be automatically precisely aligned to this axis when received within the bore, without the need for complex alignment procedures and fixtures. Additionally, because the emitter member is not clamped or held in place by a compressive force applied by a support structure, as in a Vogel mount, the complexity and time required to mount the emitter member 224 may also be significantly reduced. In particular, the configurations of the CPB sources described herein do not require the clamping members of the support structure to be spread apart to receive the emitter filament, or the placement of a member, such as a graphite sheet, between the clamping members and the emitter filament, all of which complicate assembly and alignment operations.

[0052] Additionally, any or all of the formation of the bore, formation of the channel, placement of the emitter member, and / or application of the fastening material layer may be performed at ambient laboratory conditions (e.g., "in air") and need not be performed under vacuum. This may significantly reduce the time required to fabricate the CPB source 200 as compared to existing beam sources, particularly those that require FIB welding or fastening of components under vacuum. The manufacture of the CPB sources described herein may also be automated and / or performed on a commercial scale.

[0053] A CPB source having the structure described herein was used to measure 10 -6 The CPB source embodiments described herein were heated to a temperature of 2200 K at a pressure of Torr for approximately 1 hour and essentially no mechanical drift or loss of material from the fixed material layer was observed, demonstrating that the CPB source embodiments described herein are robust and reliable.

[0054] The CPB sources described herein may be used in any of a variety of charged particle beam systems, such as the SEM, TEM, or STEM described above, including multi-beam systems in which such microscopes are combined with other beam columns, such as focused ion beam (FIB) mills.

[0055] 13 illustrates an exemplary method of making a CPB source 200. At process block 400, with the base member 202 mounted in a chuck or fixture, a bore 226 may be formed in the mounting member 216 using, for example, a pulsed or continuous wave focused or unfocused laser beam. At process block 402, an opening / aperture / channel 230 may be formed in the free second end 222 of the mounting member 216 by, for example, a pulsed or continuous wave focused or unfocused laser beam, etching, or a photolithography process. At process block 404, with the base member 202 held in one fixture and the emitter member 224 held in another fixture, such as a micromanipulator, the emitter member may be aligned with and inserted into the bore 226. At process block 406, an anchoring material layer 242 may be applied, such as by pipetting colloidal graphite liquid into the free second end 222 of the mounting member, such that the liquid flows through the channel 230 into the bore 226 and around the emitter member 224 to coat the surfaces of the emitter member, the bore, the retaining portion, and other portions of the mounting member. When the liquid phase of the colloidal liquid has evaporated, further shaping of the emitter member 224 may be performed depending on the particular requirements of the CPB system in which the source is used. Alternatively, the anchoring material layer may be applied in other ways, such as by thin film deposition, as described above.

[0056] Explanation of terms As used in this application and the claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Additionally, the term "comprises" means "comprises." Furthermore, the term "coupled" does not exclude the presence of intermediate elements between the coupled items.

[0057] The systems, devices, and methods described herein should not be construed as limiting in any way. Instead, the present disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, both alone and in various combinations and subcombinations with one another. The disclosed systems, methods, and devices are not limited to any particular aspect or feature, or combination thereof, nor do the disclosed systems, methods, and devices require that any one or more particular advantages exist or problems be solved. While any theory of operation is for ease of explanation, the disclosed systems, methods, and devices are not limited to such theory of operation.

[0058] Although some operations of the disclosed methods are described in a particular order for convenience of presentation, it should be understood that this method of description encompasses reordering, unless a particular order is required by specific language described herein. For example, operations described in a sequence may in some cases be reordered or performed simultaneously. Furthermore, for simplicity, the accompanying drawings may not show the various ways in which the disclosed systems, methods, and apparatuses may be used with other systems, methods, and / or apparatuses. In addition, the description may use terms such as "generate" and "provide" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible to those of ordinary skill in the art.

[0059] In some instances, values, procedures, or devices may be referred to as "lowest," "best," "smallest," etc. It will be understood that such descriptions are intended to indicate that a selection from among many functional options may be used, and that such a selection is not necessarily better, smaller, or otherwise preferable than other options.

[0060] Particular examples may be described with reference to directions indicated as "above," "below," "upper," "lower," etc. These terms are used for convenience of explanation and do not imply a particular spatial orientation.

[0061] The presence of alternatives for the various components, parameters, operating conditions, etc. described herein is not intended to imply that the alternatives are necessarily equivalent and / or will perform equally well, nor is it intended that the alternatives be listed in order of preference, unless otherwise specified.

[0062] In light of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are merely examples and should not be construed as limiting the scope of the disclosure. Rather, the scope of the disclosure is at least as broad as the following claims and the equivalents of the features recited therein. Accordingly, we claim all that comes within the scope and spirit of those claims.

[0063] [Appendix 1] 1. A charged particle beam source comprising: a conductive support member coupled to the base; a mounting member coupled to the support member and defining a bore; an emitter member received within the bore, the emitter member being retained within the bore by a layer of stationary material flowed around the emitter member. [Appendix 2] the mounting member defines a longitudinal axis; 2. The charged particle beam source of claim 1, wherein the bore extends along the longitudinal axis. [Appendix 3] the mounting member includes an opening along its length longitudinally offset from a free end of the mounting member, the opening communicating with the bore; 2. The charged particle beam source of claim 1, wherein the fixing material of the fixing material layer is received within the opening. [Appendix 4] 4. The charged particle beam source of claim 3, wherein the opening is a channel formed in the mounting member. [Appendix 5] 5. The charged particle beam source of claim 4, wherein the mounting member comprises a plurality of channels spaced along its length and at least one retaining portion extending around the emitter member. [Appendix 6] the mounting member has a first end connected to the support member and the free end is a free second end; 4. The charged particle beam source of claim 3, wherein the opening is offset from the free second end toward the first end. [Appendix 7] 2. The charged particle beam source of claim 1, wherein the emitter member comprises lanthanum hexabromide (LaB6) or cesium hexabromide (CeB6). [Appendix 8] 2. The charged particle beam source of claim 1, wherein the layer of immobilized material is formed from a dispersed phase of a colloidal liquid. [Appendix 9] 9. The charged particle beam source of claim 8, wherein the layer of stationary material comprises graphite. [Appendix 10] 2. The charged particle beam source of claim 1 configured as an electron beam source. [Appendix 11] 2. The charged particle beam source of claim 1, wherein the emitter member is not clamped by other components of the charged particle beam source. [Appendix 12] 2. A scanning electron microscope comprising a charged particle beam source according to claim 1. [Appendix 13] 2. A method of making a charged particle beam source according to claim 1, comprising the steps of: forming the bore in the mounting member; inserting the emitter member into the bore of the mounting member; and flowing a colloidal liquid around said emitter member and said mounting member to form said layer of anchoring material. [Appendix 14] 2. A method of using a charged particle beam source according to claim 1, comprising the steps of: heating the emitter member to generate a charged particle beam; and directing the charged particle beam at a target. [Appendix 15] 1. A charged particle beam source comprising: a conductive support member coupled to the base; a mounting member coupled to the support member and defining a bore; an emitter member received within the bore; A charged particle beam source, wherein the mounting member comprises a retaining portion extending around the emitter member. [Appendix 16] 16. The charged particle beam source of claim 15, wherein the emitter member is retained in the bore by a layer of stationary material flowed around the emitter member in the bore. [Appendix 17] 17. The charged particle beam source of claim 16, wherein the layer of immobilized material is formed from a dispersed phase of a colloidal liquid. [Appendix 18] 16. The charged particle beam source of claim 15, further comprising a channel defined in the mounting member. [Appendix 19] 16. The charged particle beam source of claim 15, wherein the bore and the emitter member each have a rectangular cross-section. [Appendix 20] 1. A charged particle beam source comprising: a conductive support member coupled to the base; a mounting member coupled to the support member and defining a bore; an emitter member received in the bore and retained therein by a layer of anchoring material; A charged particle beam source, wherein the cross section of the bore is larger than the cross section of the emitter member. [Appendix 21] 21. The charged particle beam source of claim 20, wherein the emitter member is not clamped by the mounting member.

Claims

1. 1. A charged particle beam source comprising: a mounting member having a first opening at a free end thereof and a bore extending from the first opening into the mounting member along a longitudinal axis of the mounting member; a second opening defined in a sidewall of the mounting member and extending between an outer surface of the mounting member and the bore, the second opening being spaced from the first opening along the longitudinal axis of the mounting member; an emitter member received within the bore and aligned along the longitudinal axis of the mounting member; a fastener received within the bore and within the second opening to retain the emitter member within the bore; the attachment member is coupled to and extends from a curved, electrically conductive hairpin member; Charged particle beam source.

2. the fastening material extends at least partially around an outer surface of the mounting member; 2. The charged particle beam source of claim 1.

3. the emitter member extends beyond the second opening in the sidewall of the mounting member in a direction toward the hairpin member.

2. The charged particle beam source of claim 1.

4. the second opening comprises a channel or a slot; 2. The charged particle beam source of claim 1.

5. The second opening is one of a plurality of second openings arranged around the periphery of the mounting member.

2. The charged particle beam source of claim 1.

6. the fastening material coats an inner surface of the bore and extends around the emitter member within the bore to cover the emitter member within the bore; 2. The charged particle beam source of claim 1.

7. The emitter member includes lanthanum hexaboride (LaB6) or cesium hexaboride (CeB6); 2. The charged particle beam source of claim 1.

8. The fastening material comprises graphite.

2. The charged particle beam source of claim 1.

9. A scanning electron microscope comprising the charged particle beam source according to claim 1.

10. 13. A method of making a charged particle beam source according to claim 1, comprising the steps of: forming the bore in the mounting member; inserting the emitter member into the bore of the mounting member; and flowing a colloidal liquid around the emitter member and the mounting member to form an anchoring material. method.

11. 2. A method of using the charged particle beam source of claim 1, comprising the steps of: heating the emitter member to generate a charged particle beam; directing the charged particle beam at a target; method.

12. 1. A charged particle beam source comprising: a curved hairpin member comprising an electrically conductive material; an attachment member coupled to and extending from an apex of the hairpin member and having a free end; a bore defined in the mounting member and extending along a longitudinal axis of the mounting member, the bore including an opening at the free end of the mounting member; an emitter member received within the bore and aligned along the longitudinal axis of the mounting member; a coating on an inner surface of the bore and extending around the emitter member within the bore; a layer of anchoring material covering the emitter member within the bore; the opening at the free end of the mounting member is a first opening; The mounting member further includes a second opening defined in a sidewall of the mounting member and extending between an outer surface of the mounting member and the bore, the second opening being spaced from the first opening along the longitudinal axis, and the layer of anchoring material being received within the second opening. Charged particle beam source.

13. the emitter member extends beyond the second opening in the sidewall of the mounting member in a direction toward the hairpin member.

13. The charged particle beam source of claim 12.

14. A charged particle beam source comprising: a curved hairpin member comprising an electrically conductive material; an attachment member coupled to and extending from an apex of the hairpin member and having a free end; a bore defined in the mounting member and extending along a longitudinal axis of the mounting member, the bore including an opening at the free end of the mounting member; an emitter member received within the bore and aligned along the longitudinal axis of the mounting member; a coating on an inner surface of the bore and extending around the emitter member within the bore; a layer of anchoring material covering the emitter member within the bore; the layer of fastening material extends at least partially around an outer surface of the mounting member; Charged particle beam source.

15. 1. A charged particle beam source comprising: a mounting member having a first opening at a free end of the mounting member and a bore extending from the first opening into the mounting member along a longitudinal axis of the mounting member; an emitter member received within the bore and aligned along the longitudinal axis of the mounting member; a fastener material received at least partially within the bore and about an outer surface of the mounting member to retain the emitter member within the bore; the attachment member is coupled to a curved conductive hairpin member and extends from the hairpin member along the longitudinal axis of the attachment member; the opening at the free end of the mounting member is a first opening; the mounting member further comprising a second opening defined in a sidewall of the mounting member and extending between an outer surface of the mounting member and the bore; the second opening is spaced from the first opening along the longitudinal axis; The stationary material is received within the second opening.

16. the fastening material coats an inner surface of the bore and extends around the emitter member within the bore to cover the emitter member within the bore; 16. The charged particle beam source of claim 15.

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