Increasing deposition rate with insulating covers for GIS manipulators

Abstract

A system for depositing material on a sample in a localized region of the sample is provided, the system including a vacuum chamber, a heat reservoir disposed outside the vacuum chamber, a sample support configured to hold the sample within the vacuum chamber during a sample evaluation process, a charged particle beam column configured to direct a charged particle beam into the vacuum chamber toward the sample so that the charged particle beam collides with the sample in a deposition region, a gas injection system configured to deliver a process gas to the deposition region of the sample, and a heat shield spaced from and disposed between the gas injection system and the sample, the heat shield having high thermal conductivity and low emissivity and thermally coupled to the heat reservoir to transfer heat radiated from the gas injection system to the heat reservoir.

Description

[Technical Field]

[0001] This application claims the benefit of U.S. Patent Application No. 17 / 891,028, filed August 18, 2022, the entire disclosure of which is incorporated herein by reference for all purposes. [Background technology]

[0002] In the study of electronic materials and processes for fabricating such materials into electronic structures, samples of the electronic structures may be used for microscopy for failure analysis and device validation purposes. For example, a sample such as a silicon, gallium nitride, or other type of wafer containing one or more integrated circuits (ICs) or other electronic structures formed thereon may be milled with a focused ion beam (FIB) and / or analyzed with a scanning electron microscope (SEM) to study the intrinsic properties of the circuits or other structures formed on the wafer.

[0003] FIB and SEM tools are similar in that they each include a charged particle column that generates a charged particle beam and directs that beam toward a sample. However, as their names suggest, the charged particle beam generated by a FIB column is a focused beam of ions, while the charged particle beam generated by an SEM column is a focused beam of electrons.

[0004] While FIB and SEM tools (and FIB-SEM tools, including both FIB and SEM columns) are often used to analyze and otherwise characterize structures within a sample, they can also be used to etch or deposit materials on a sample. For example, a focused ion beam can be scanned across the surface of a sample while a gas injection system directs a flow of deposition precursor gas to the scanned area, selectively depositing material in the scanned area with nanometer precision, according to a technique often referred to as focused ion beam-enhanced deposition, or FIB-enhanced deposition for short. During the FIB-enhanced deposition process, molecules of the injected gas attach to the surface of the sample. As the ion beam is scanned across an area of ​​the sample, energy released by the collision cascade of bombarding ions causes dissociation of precursor molecules adsorbed on the surface, resulting in a solid deposit on the surface along with the release of volatile residues. As another example, a deposition gas can be introduced to the sample near where an electron beam is scanned across the surface of the sample to deposit material under an SEM column.

[0005] Although FIB-enhanced deposition is used in many different applications and uses, improved deposition techniques are continually being sought. Summary of the Invention

[0006] Embodiments of the present disclosure relate to improved methods and systems for charged particle beam-enhanced deposition, such as focused ion beam-enhanced deposition. The embodiments can be used to increase the deposition rate of charged particle beam-enhanced deposition, thereby increasing the throughput of processes that use charged particle beam-enhanced deposition. While embodiments of the present disclosure can be used to increase the rate at which material is deposited on a variety of different types of samples, some embodiments are particularly useful when depositing material on samples that are semiconductor wafers or similar specimens.

[0007] In some embodiments, a system for depositing material on a sample in a localized region of the sample is provided, the system including a vacuum chamber, a heat reservoir disposed outside the vacuum chamber, a sample support configured to hold the sample within the vacuum chamber during a sample evaluation process, a charged particle beam column configured to direct a charged particle beam into the vacuum chamber toward the sample so that the charged particle beam collides with the sample in a deposition region, a gas injection system configured to deliver a process gas to the deposition region of the sample, and a heat shield spaced apart from and disposed between the gas injection system and the sample, the heat shield having high thermal conductivity and low emissivity and thermally coupled to the heat reservoir to transfer heat radiated from the gas injection system to the heat reservoir.

[0008] In various embodiments, the system may include one or more of the following features. The charged particle beam column may be a focused ion beam column, and the charged particle beam may be a focused ion beam. The heat-insulating shield may have an emissivity coefficient of 0.1 or less. The system may further include a heating element operably coupled to heat the gas injection system above room temperature. The heat-insulating shield may include aluminum. The gas injection system may include a gas nozzle including a channel formed through a distal end of the nozzle, the channel aligned to allow the focused ion beam to pass through the channel to the sample. The gas injection system may include a base portion and a nozzle extending away from the base portion. The base portion may have a thermal mass significantly greater than a thermal mass of the nozzle, and a heat shield may be disposed between the base portion and the sample and between a portion of the nozzle and the sample. The gas nozzle may include a high-emissivity material. The distal end of the gas nozzle may extend beyond the outer periphery of the heat shield. The distal end of the gas nozzle may be coated with a low-emissivity material. The gas nozzle may include stainless steel, and the distal end of the gas nozzle may be coated with aluminum. The distal end of the gas nozzle can include a low-emissivity material. The distal end of the gas nozzle can include aluminum. The thermal mass can be a chamber cover. The thermal mass can weigh at least 100 kg.

[0009] In some embodiments, a method for depositing material on a sample at a deposition region of the sample using a focused ion beam column is provided. The method includes: placing the sample in a vacuum chamber such that the deposition region is within a field of view of the focused ion beam column; injecting a deposition precursor gas into the vacuum chamber at a location adjacent to the deposition region with a gas injection system; generating a focused ion beam using the focused ion beam column and focusing the ion beam within the deposition region of the sample; and scanning the focused ion beam across the deposition region of the sample to excite molecules of a deposition gas adhering to the sample surface in the deposition region and deposit material on the sample in the deposition region. Additionally, while the focused ion beam is scanned across the deposition region, the method can protect the sample from heat radiated from the gas injection system using a thermal insulation shield comprising a highly conductive, low emissivity material.

[0010] In various embodiments, the method may include one or more of the following: The charged particle beam column may be a focused ion beam column, and the charged particle beam may be a focused ion beam. The method may further include heating the gas injection system to above room temperature. The thermal insulating shield may include aluminum. The gas injection system may include a gas nozzle including a channel formed through a distal end of the nozzle, the channel aligned to allow the focused ion beam to pass through the channel to the sample. The gas injection system may include a base portion and a nozzle extending away from the base portion. The base portion may have a thermal mass significantly greater than a thermal mass of the nozzle, and a thermal shield may be disposed between the base portion and the sample and between a portion of the nozzle and the sample.

[0011] For a better understanding of the nature and advantages of the present disclosure, reference should be made to the following description and accompanying drawings. It should be understood, however, that each of the figures is provided for illustrative purposes only, is not to scale, and is not intended as a definition of the limits of the scope of the present disclosure. Also, as usual, and unless otherwise apparent from the description, when elements in different figures use the same reference numerals, those elements are generally identical or at least similar in function or purpose. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a simplified schematic diagram of a sample particle beam deposition system. [Figure 2] FIG. 1 is a simplified schematic diagram of a particle beam deposition system according to certain embodiments disclosed herein. [Figure 3] FIG. 3 is an enlarged view of a portion of the particle beam deposition system shown in FIG. 2. [Figure 4] FIG. 1 is a simplified cross-sectional view of a portion of a sample focused ion beam system. [Figure 5A] FIG. 1 is a simplified cross-sectional view of a portion of a sample focused ion beam system according to certain embodiments disclosed herein. [Figure 5B] 5B is a simplified cross-sectional view of a portion of the heat shield shown in FIG. 5A. [Figure 6] 1 is a simplified diagram of a gas injection system according to certain embodiments disclosed herein. [Figure 7] 1 is a flowchart illustrating steps associated with a method for depositing material using a focused ion beam, according to some embodiments. [Figure 8] 1 is a simplified diagram of a sample on which a material may be deposited according to embodiments disclosed herein; DETAILED DESCRIPTION OF THE INVENTION

[0013] Embodiments of the present disclosure relate to improved methods and systems for charged particle beam-enhanced deposition, such as focused ion beam-enhanced deposition. The embodiments can be used to increase the deposition rate of charged particle beam-enhanced deposition, thereby increasing the throughput of processes that use charged particle beam-enhanced deposition. In some cases, the embodiments can also be used to modify the chemical composition of the deposited material to improve the deposition process.

[0014] Example Focused Ion Beam (FIB) Tool To better understand and appreciate the present disclosure, reference is first made to Figure 1, which is a simplified schematic diagram of a previously known focused ion beam (FIB) characterization system 100. FIB system 100 can be used for particle-enhanced deposition of various materials on semiconductor wafers, among other processes.

[0015] 1, system 100 can include, among other elements, a vacuum chamber 110 along with a focused ion beam (FIB) column 120. A support element 140 can support a sample 130 (e.g., a semiconductor wafer) within chamber 110 during processing, where the sample 130 (sometimes referred to herein as a "target" or "specimen") receives a charged particle beam from FIB column 120.

[0016] During a process, one or more gases can be delivered into chamber 110 by gas injection system 150 for a particular process. For ease of illustration, gas injection system 150 is depicted in FIG. 1 as a nozzle; however, it should be noted that gas injection system 150 can include, among other elements, a gas reservoir, a gas source, a valve, one or more inlets, and one or more outlets. In some embodiments, gas injection system 150 can be configured to deliver gas to a localized portion of sample 130 exposed to the scanning pattern of the charged particle beam, as opposed to delivering gas to the entire upper surface of sample 130. For example, in some embodiments, gas injection system 150 has a nozzle opening diameter measured in the hundreds of microns (e.g., 400-500 microns) that is configured to deliver gas directly to a relatively small portion of the surface of the sample that encompasses the scanning pattern of the charged particle beam.

[0017] The FIB column 120 is connected to the vacuum chamber 110 such that the charged particle beam generated by the FIB column propagates through the vacuum environment created within the vacuum chamber 110 before striking the sample 130. For example, as shown in FIG. 1 , the FIB column 120 can generate a focused ion beam 125 that travels through the vacuum environment of the chamber 110 before colliding with the sample 130.

[0018] The FIB column 120 can machine the sample 130 (e.g., drill a recess in the sample 130) to create a cross-section by irradiating the sample with a charged particle beam 125, and can also smooth the cross-section if desired. The FIB machining process generally involves placing the sample in a vacuum environment and directing a focused beam of ions toward the sample to etch or machine away material on the sample. In some cases, the vacuum environment can be purged with a controlled concentration of background gas, which serves to help control the etch rate and quality or to help control material deposition. The accelerated ions can be generated from xenon, gallium, or other suitable elements and are accelerated toward the sample by a voltage typically in the range of 500 to 100,000 volts, more typically in the range of 3,000 to 30,000 volts. Beam currents are typically in the range of a few picoamps to a few microamps, depending on the FIB instrument configuration and application, and pressures generally range from 10 to 100 psi in different parts of the system and in different processing modes. -10 From 10 -5 It is controlled between mbar.

[0019] The mechanical treatment process may be performed, for example, by (i) locating a location to be mechanically treated to remove a portion of material (e.g., a portion of one or more layers) from the sample, (ii) moving the sample (e.g., by mechanical support element 140) so that the sample is within the field of view of the FIB unit, and (iii) mechanically treating the sample to remove the desired amount of material at the location. The mechanical treatment process may include forming an indentation in the sample (typically a few microns to a few hundred microns in size in lateral dimensions).

[0020] Mechanical processing generally involves scanning a charged particle beam back and forth (e.g., in a raster or other scanning pattern) over a specific area of ​​the sample being imaged or machined. As known to those skilled in the art, one or more lenses (not shown) coupled to the charged particle column can implement the scanning pattern. The scanned area is generally a very small fraction of the total area of ​​the sample. For example, the sample may be a semiconductor wafer having a diameter of 150, 200, or 300 mm, but each scanned area on the wafer (i.e., the machined area) may be a rectangular area having a width and / or length measured in microns or tens of microns. Each iteration (or frame) of the ion beam scanned over the area being machined is typically measured in microseconds and removes an extremely small amount of material (e.g., as low as 0.01 atomic layers using a low i probe (e.g., 10 pA), or as much as 1000 atomic layers using a high i probe (e.g., 1000 nA)), and the scan pattern is then repeated thousands or even millions of times to etch holes to the desired depth.

[0021] During mechanical processing, the charged particle beam 120 generated by the FIB column 120 propagates through a vacuum environment formed within the vacuum chamber 110 before striking the sample 130. The mechanical processing generates by-products, such as molecules, atoms, and ions of the material being mechanically processed, along with secondary electrons. For example, when ions strike the sample surface with relatively high energy levels, they can initiate a collision cascade, transferring momentum and energy from the ions to the sample until they are stopped and implanted. The momentum and energy transfer during the collision cascade can cause atomic rearrangement, ionization of atoms, and the generation of phonons (heat). The cascade can reach the sample surface, causing sputtering of atoms with sufficient momentum and energy to escape the solid sample, generating secondary ions and electrons as a combination of ionization and sputtering, which also escape the sample surface. The secondary ions or electrons can be detected by an appropriate detector (not shown). The detected secondary ions or electrons can then be used to analyze the properties of the machined layers and structures.

[0022] 1, FIB system 100 may include one or more controllers, processors, or other hardware units that control the operation of system 100 by executing computer instructions stored in one or more computer-readable memories, as would be known to one of ordinary skill in the art. By way of example, the computer-readable memories may include solid-state memory (such as random access memory (RAM) and / or read-only memory (ROM), which may be programmable, flash-updateable, etc.), disk drives, optical storage devices, or similar non-transitory computer-readable storage media.

[0023] Charged particle enhanced deposition process Some embodiments of the present disclosure can deposit material onto a sample disposed on a support 140 by initiating a deposition process beneath the FIB column 120. As an example, in some embodiments, the FIB column 120 can be used in a deposition mode to initiate a focused ion beam-enhanced deposition process. To this end, a deposition gas can be supplied to the sample 130 by the gas injection system 150, and energy from the FIB column 120 can generate an ion beam 125. A cascade of incident ions then excites the deposition gas, resulting in deposition of material on the sample that is localized to the region of the sample scanned by the ion beam. Thus, deposition occurring according to such embodiments does not occur simultaneously across the entire surface of the sample or wafer being processed. Instead, deposition occurs only in the approximate area where the ion beam strikes the wafer (which, by way of non-limiting example, can have a diameter in the range of 0.5 to 25 microns for a xenon plasma) as the ion beam is scanned across those areas of the wafer. Thus, deposition according to some embodiments can be performed with micron-level resolution.

[0024] The rate at which material is deposited in such a focused ion beam (FIB)-enhanced deposition process can directly affect the throughput of the process. Thus, a higher deposition rate can equivalently increase throughput. During a FIB deposition process, the rate at which material is deposited on a sample depends on many different factors, including the energy level of the charged particle beam, the precursor gas used in the deposition process, the type of material on the surface of the sample, and the temperature of the sample surface. For example, in a FIB-enhanced deposition process, the molecular sticking coefficient is one of the parameters that governs the deposition rate. The sticking coefficient is a measure of the probability that airborne molecules will stick when they come into contact with the surface of the sample. As the deposition gas sticking coefficient increases, the deposition rate of the FIB-enhanced deposition process increases. For some precursor gases, the sticking coefficient is inversely dependent on temperature. That is, as the temperature increases, the sticking coefficient decreases, but as the temperature decreases, the sticking coefficient increases.

[0025] In some applications, it is important to heat gas injection system 150 to temperatures well above room temperature (e.g., to about 85-95 degrees Celsius in some applications) to avoid deposition of materials from gases flowing through the gas injection system, which may interfere with gas flow to the machine processing area or completely clog portions of the gas injection system, such as the gas nozzle. Gas injection system 150, which can include various components made from metals such as stainless steel with relatively high emissivity, can be operably coupled to a heater element (not shown) that heats the gas injection system to a sufficient temperature to prevent or reduce deposition within the gas injection system. In some embodiments, the gas injection system can include one or more components in addition to the gas nozzle in combination with a component that exhibits a relatively large thermal mass near the sample (e.g., a thermal mass at least as large as the sample itself).

[0026] During the FIB-enhanced deposition process, the heated gas injection system 150 radiates heat (as indicated by arrows 155) toward the sample 130. The radiated heat can unnecessarily increase the temperature at the surface of the sample 130 in the area where the ion beam 125 impacts the sample. The increased surface temperature can then reduce the sticking coefficient of the deposition gas introduced to the sample surface by the gas injection system 150, unnecessarily slowing the deposition rate.

[0027] Enhancement of deposition rate in charged particle enhanced deposition processes To facilitate higher deposition rates, and thus higher throughput rates, some embodiments of the present disclosure may include a thermal insulation shield around a portion of the gas injection system 150 to reduce or prevent heat radiating from the gas injection system from reaching the surface of the sample. Figure 2 is a simplified schematic diagram of a sample FIB system 200 according to some embodiments disclosed herein. FIB system 200 includes many of the same components as system 100 discussed above, including, for example, a vacuum chamber, a FIB column, a sample support capable of supporting a sample during processing (e.g., FIB-enhanced deposition), and a gas injection system. Thus, for ease of reference, like reference numbers are used for like components, and descriptions of such like components will not be repeated to avoid unnecessary repetition.

[0028] The FIB system 200 further includes a heat shield 210 disposed between the gas injection system 150 and the sample 130. The heat shield 210 may be made of a material with good thermal conductivity but low emissivity (i.e., an emissivity coefficient of 0.1 or less), such as aluminum, and may be thermally coupled to a chamber cover or similar large heat storage material disposed outside the vacuum chamber 110, away from the sample 130. For example, in some embodiments, the FIB system 200 includes a large, heavy chamber cover (not shown) over the vacuum chamber 110. The chamber cover, which may be electrically grounded and kept at or near room temperature, may weigh 100 kg or more, and in some embodiments, 200 kg or more, and may be made of a thermally conductive metal such as stainless steel or aluminum.

[0029] Adiabatic shield 210 is spaced from gas injection system 150 such that the adiabatic shield is positioned between the sample and a portion of the gas injection system without physical contact with gas injection system 150. Thus, there is no thermal conductivity between adiabatic shield 210 and gas injection system 150. Instead, adiabatic shield 210 may be in direct physical contact with and thermally coupled to the chamber cover (or other heat reservoir) so as to be kept at a temperature lower than that of the gas injection system. In this manner, the adiabatic shield may dissipate heat generated by gas injection system 150 away from sample 130 and toward the chamber cover. For example, as shown in FIG. 3 , which is a close-up view of a portion of FIB system 200, heat radiating from gas injection system 150 (indicated by arrows 155) is blocked or captured by adiabatic shield 210 and directed, as indicated by arrows 215, away from sample 130 toward the chamber cover (or a similarly large heat reservoir outside chamber 110, which may be kept at room temperature, for example). Because the adiabatic shield 210 has low emissivity, the amount of heat it re-radiates towards the sample 130 is minimal (and significantly less than the heat radiated by the gas injection system).

[0030] Some FIB systems include a gas injection system in which the tip portion of the gas nozzle is positioned directly between the end of the FIB column and the sample. For example, FIG. 4 shows a portion of a FIB system 400 including a gas injection system 450 including a gas nozzle 460 positioned between the distal end of the FIB column 120 and the sample 130. The gas nozzle 460 has a fixed relationship in the X and Y planes with respect to the FIB column 120 and may be movable in the Z plane to allow the nozzle to be in close proximity to the upper surface of the sample 130 (e.g., as close as 300 microns in some embodiments). As shown, the gas nozzle 460 includes a hole or channel 462 formed therethrough and a nozzle opening 464. The channel 462 allows the ion beam 125 to pass through the gas nozzle and impact the sample 130 at a location directly below the nozzle. The nozzle opening 464, which may have a diameter larger than the diameter of the channel 462, allows gas to exit the nozzle 460 adjacent to the surface of the sample 130.

[0031] 5A is a simplified cross-sectional view of a FIB deposition system 500, according to some embodiments. As shown in FIG. 5A, the FIB deposition system 500 includes a gas injection system 550 similar to the gas injection system 450, which includes a gas nozzle 560 including a channel 562 that allows the ion beam to pass through the gas injection nozzle and collide with the sample 130 at a location directly below the nozzle, and a nozzle opening 564 that allows the gas to exit the nozzle 560 adjacent an upper surface of the sample 130. The gas injection system 550 and the gas nozzle 560 are positionable in the Z plane such that the nozzle opening 564 of the gas nozzle 560 is very close to the sample 130 (e.g., as close as 300 microns in some embodiments).

[0032] The FIB deposition system 500 also includes a heat-insulating shield 510 that partially surrounds a portion of the gas injection system 550 and is positioned between the gas injection system 550 and the sample 130. For example, as shown in FIG. 5B , which is a simplified cross-sectional view of a portion of the heat-insulating shield 510, the shield 510 includes a bottom wall 512 and a sidewall 514 that surrounds the gas injection system 550 on at least three sides. To allow the gas opening 564 of the gas nozzle 560 to be positioned very close to the sample 130, in some embodiments, the heat-insulating shield 510 does not extend between the tip portion of the gas nozzle 560 and the sample 130. The end of the nozzle 560 represents a relatively small fraction of the overall thermal mass of the gas injection system 550. Thus, not covering the tip portion of the nozzle 560 with the heat-insulating shield 510 does not result in a significant amount of heat being radiated from the nozzle to the sample 130.

[0033] Additionally, in some embodiments, at least a portion of gas nozzle 460 not covered by thermal adiabatic shield 510 is coated with a low-emissivity coating, such as aluminum. Thus, for example, in some embodiments, gas nozzle 560 may be made from a relatively high-emissivity metal, such as stainless steel, and coated with a low-emissivity layer, such as aluminum. The aluminum coating may be applied using any known suitable coating technique, such as electroplating. In yet other embodiments, gas injection nozzle 460 may be made from a low-emissivity material, such as aluminum.

[0034] While the various embodiments discussed above include gas injection systems having gas nozzles with relatively straight shapes, in other embodiments, the gas nozzles may be curved to include various curves such that there are no right angles in the path that delivers gas across the nozzle. One example of a suitable nozzle design is described in commonly assigned U.S. Patent No. 6,992,288, which is incorporated herein by reference in its entirety.

[0035] Reference is now made to Figure 6, which is a simplified diagram of a gas injection system 600, according to some embodiments. As shown in Figure 6, gas injection system 600 can include a gas nozzle 610 and a base portion 620. Gas nozzle 610 includes a channel 612, as described above with respect to channel 562, that allows an ion beam (e.g., ion beam 125) to pass through the gas nozzle and collide with a sample at a location directly below the nozzle. Gas nozzle 610 also includes a nozzle opening 614 at a bottom surface of the gas nozzle in the region of channel 612 that delivers gas introduced into the gas injection system to an upper surface of the sample.

[0036] Base portion 620 may be a relatively large metal object that supplies gas to nozzle portion 610 and is coupled to a heater (e.g., a resistance heater) to heat gas injection system 600, including nozzle 610, to a desired temperature to prevent or reduce deposition within the gas injection system, as discussed above. In some embodiments, base portion 620 may be disposed within a vacuum chamber of a FIB tool, e.g., within vacuum chamber 110, and may radiate heat toward a sample being processed. Accordingly, some embodiments of the present disclosure may include a heat shield disposed between both gas nozzle 610 and base portion 620 to capture heat radiated from nozzle 610 and base portion 620. As described above, the heat shield may be thermally coupled to a heat sink, such as a chamber cover, having a large thermal mass disposed outside the chamber to dissipate heat away from the sample, as described above. The footprint of adiabatic shield 630, representing the bottom surface of adiabatic shield 630 positioned directly below gas injection system 600 and disposed between the gas injection system and the sample, is shown in dashed lines in FIG. 6. As shown in FIG. 6, the tip portion of gas nozzle 610 can extend beyond the periphery of adiabatic shield 630, similar to that discussed above with respect to FIG. 5. Adiabatic shield 630 can be made from a highly thermally conductive material with low emissivity, as discussed above, and can have a sidewall (not shown) and a base portion 620 that extend from the bottom surface of the shield upward toward the chamber cover that surrounds the sides of nozzle 610. In some embodiments, the sidewall of the adiabatic shield is in physical contact with the chamber cover (acting as a large heat sink), allowing the adiabatic shield to dissipate heat radiated from the gas injection system to the chamber cover.

[0037] Example FIB Deposition Process To further illustrate embodiments of the present disclosure, reference is made to FIGS. 7 and 8. FIG. 7 is a flowchart illustrating steps associated with a method 700 according to some embodiments, and FIG. 8 is a simplified diagram of a sample 800, which may be representative of sample 130. According to method 700, material can be deposited on sample 800 by a charged particle beam-enhanced deposition process. Method 700 begins by placing the sample in a processing chamber of a sample evaluation system (block 710). The processing chamber, which may be, for example, chamber 200, can include one or more charged particle beam columns operable in a deposition mode to deposit material on sample 800 in one or more localized regions. Block 710 can include placing sample 800 in a vacuum chamber on a sample support, such as support 140.

[0038] In many cases, sample 800 will include multiple different regions onto which material is deposited. For example, FIG. 8 shows a top view of sample 800 along with two enlarged views of specific portions of sample 800. Sample 800 may be, for example, a 150 mm, 200 mm, or 300 mm semiconductor wafer and may include multiple integrated circuits 810 (52 in the example shown) formed thereon. The integrated circuits 810 may be at an intermediate stage of fabrication, and method 700 may be used to deposit material onto one or more regions 820 of the integrated circuits. For example, enlarged view A of FIG. 8 shows multiple regions 820 of one of the integrated circuits 810 onto which material may be deposited according to the techniques described herein. Enlarged view B shows one of those regions 820 in more detail.

[0039] 7, support 140 can be moved and positioned so that the area where material is to be deposited on the sample (e.g., one of regions 820, referred to herein as the "deposition region") is located directly beneath the tip of the focused ion beam column (step 720). A deposition precursor gas can then be injected into chamber 110 at a location proximate to the deposition region by gas injection system 150, which can be heated as discussed above and protected from radiating heat toward sample 800 by a thermal insulating shield according to the present disclosure (step 730).

[0040] During step 730, molecules of the deposition precursor gas attach to the surface of the sample according to the sticking coefficient of the precursor gas. While the gas is being delivered to the deposition region and the deposition region is cooling, a charged particle beam (e.g., an ion beam) can be generated (step 740) and focused and scanned over a region of interest on the sample (step 750). The charged particle beam can be focused by a focusing lens and scanned over an area of ​​the substrate by one or more deflection lenses (not shown). As discussed above, a cascade of charged particles from beam 125 can excite molecules of the deposition gas attached to the sample in the deposition region, resulting in the deposition of material on the sample that is localized in the region of the sample scanned by the ion beam. For example, the charged particle beam can dissociate the precursor gas, breaking it down into volatile and non-volatile components. In this case, the non-volatile components remain on the surface of the sample as the deposited material. Although embodiments can be used to deposit many different types of materials and are not limited to the use of any particular deposition precursor gas, as one specific example, a deposition precursor gas that can be dissociated by a charged particle beam can be tungsten hexacarbonyl (W(CO)), leaving a layer of tungsten material deposited on the sample in a localized deposition region.

[0041] In a practical embodiment, steps 740 and 750 may be performed very rapidly, essentially simultaneously, and step 730 may be maintained while steps 750 and 760 are performed (i.e., deposition gases may continue to be injected into the chamber).

[0042] Once material from the precursor gas is deposited during the first deposition, if there are additional areas on the sample on which to deposit material (step 760), the sample can be moved via the substrate support to position the next or subsequent deposition area under the tip of the charged particle column (block 720). Otherwise, the deposition process is complete and the sample can be transferred from the system 100 or processed (step 770).

[0043] Additional Embodiments The above description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that specific details are not required to practice the described embodiments. Accordingly, the above description of the specific embodiments described herein is presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. For example, while the above embodiments describe a focused ion column as part of a tool having a single charged particle column, in some embodiments, the focused ion beam column can be located in a SEM-FIB tool having both a scanning electron microscope column and a focused ion beam column.

[0044] Also, while different embodiments of the present disclosure have been disclosed above, the specific details of particular embodiments may be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present disclosure. Moreover, it will be apparent to those skilled in the art that many modifications and variations are possible in light of the above teachings. It should therefore be understood that the appended claims are intended to cover all such modifications and variations as fall within the true spirit and scope of the embodiments of the present disclosure.

[0045] Additionally, any reference in this specification above to a method should apply mutatis mutandis to a system capable of carrying out the method, and should apply mutatis mutandis to a computer program product storing instructions that, when executed, result in the performance of the method. Similarly, any reference in this specification above to a system should apply mutatis mutandis to a method that may be performed by the system, and should apply mutatis mutandis to a computer program product storing instructions that may be executed by the system. Any reference in this specification to a computer program product should apply mutatis mutandis to a method that may be performed upon execution of instructions stored in the computer program product, and should apply mutatis mutandis to a system configured to execute instructions stored in the computer program product.

[0046] Also, to the extent that the illustrated embodiments of the present disclosure can be implemented, in large part, using electronic components and circuits known to those skilled in the art, the details of such will not be described to a greater extent than is deemed necessary, as explained above, for an understanding and appreciation of the concepts underlying the present disclosure and in order not to obscure or detract from the teachings of the present disclosure.

Claims

1. 1. A system for depositing material on a sample to a localized area of ​​the sample, comprising: a vacuum chamber; a heat storage material disposed outside the vacuum chamber; a sample support configured to hold a sample within the vacuum chamber during a sample evaluation process; a charged particle beam column configured to direct a charged particle beam into the vacuum chamber toward the sample such that the charged particle beam collides with the sample in a deposition region; a gas injection system configured to deliver a process gas to the deposition region of the sample; a heat-insulating shield spaced from and disposed between the gas injection system and the sample, the heat-insulating shield having high thermal conductivity and low emissivity and thermally coupled to the heat storage material to transfer heat radiated from the gas injection system to the heat storage material.

2. The system of claim 1 , wherein the charged particle beam column is a focused ion beam column and the charged particle beam is a focused ion beam.

3. The system of claim 1 , further comprising a heating element operably coupled to heat the gas injection system to a temperature above room temperature.

4. The system of claim 1 , wherein the heat shield comprises aluminum.

5. 10. The system of claim 1, wherein the gas injection system comprises a gas nozzle including a channel formed through a distal end of the gas nozzle and aligned to allow a focused ion beam to pass through the channel to the sample.

6. 2. The system of claim 1, wherein the gas injection system comprises a base portion and a nozzle extending away from the base portion, the base portion having a thermal mass significantly greater than a thermal mass of the nozzle, and the adiabatic shield is disposed between the base portion and the sample and between a portion of the nozzle and the sample.

7. The system of claim 6 , wherein the gas nozzle comprises a high-emissivity material.

8. The system of claim 7 , wherein a distal end of the gas nozzle extends beyond an outer periphery of the heat shield.

9. The system of claim 8 , wherein the distal end of the gas nozzle is coated with a low-emissivity material.

10. 10. The system of claim 9, wherein the gas nozzle comprises stainless steel and the distal end of the gas nozzle is coated with aluminum.

11. The system of claim 6 , wherein the distal end of the gas nozzle comprises a low-emissivity material.

12. The system of claim 11 , wherein the distal end of the gas nozzle comprises aluminum.

13. 10. The system of claim 1, wherein the thermal mass weighs at least 100 kg.

14. The system according to any one of claims 1 to 13, wherein the heat storage material is a chamber cover.

15. 1. A method for depositing material on a sample using a focused ion beam column in a deposition region of the sample, comprising: placing a sample in a vacuum chamber such that the deposition region is within a field of view of the focused ion beam column; injecting a deposition precursor gas into the vacuum chamber adjacent to the deposition region with a gas injection system; generating a focused ion beam using the focused ion beam column and focusing the focused ion beam within the deposition region of the sample; scanning the focused ion beam across a deposition region of the sample to excite molecules of a deposition gas adhering to a surface of the sample in the deposition region and deposit material on the sample in the deposition region; The method further comprising using a thermal insulating shield comprising a highly conductive, low emissivity material to protect the sample from heat radiated from the gas injection system while the focused ion beam is scanned across the deposition region.

16. 16. The method of depositing a material on a sample according to claim 15, wherein the charged particle beam column is a focused ion beam column and the charged particle beam is a focused ion beam.

17. 16. The method of claim 15, further comprising heating the gas injection system to a temperature above room temperature.

18. 16. The method of depositing a material on a sample of claim 15, wherein the thermal insulating shield comprises aluminum.

19. 16. The method of depositing a material on a sample of claim 15, wherein the gas injection system comprises a gas nozzle including a channel formed through a distal end of the gas nozzle and aligned to allow the focused ion beam to pass through the channel to the sample.

20. 20. The method of claim 15, wherein the gas injection system comprises a base portion and a nozzle extending away from the base portion, the base portion having a thermal mass significantly greater than a thermal mass of the nozzle, and the adiabatic shield is disposed between the base portion and the sample and between a portion of the nozzle and the sample.

Images