Deposition rate is enhanced by a thermal insulation cover for GIS manipulators.

Abstract

A system for depositing material over a sample in a localized region of the sample, the system comprising: a vacuum chamber; a thermal mass disposed outside the vacuum chamber; a sample support configured to hold the sample within the vacuum chamber during sample evaluation processing; a charged particle beam column configured to guide a charged particle beam toward the sample into the vacuum chamber such that the charged particle beam collides with the sample in the deposition region; a gas injection system configured to deliver a processing gas to the deposition region of the sample; and a thermally insulating shield spaced apart from the gas injection system and the sample and disposed between the gas injection system and the sample, wherein the thermally insulating shield has high thermal conductivity and low emissivity, and is thermally coupled to the thermal mass to transfer heat radiated from the gas injection system to the thermal mass.

Description

[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 the processing of such materials into electronic structures, samples of electronic structures can be used for microscopic examination for purposes of fault analysis and device verification. For example, samples of wafers such as silicon, gallium nitride, or other types, including one or more integrated circuits (ICs) or other electronic structures formed thereon, can be ground with a focused ion beam (FIB) and / or analyzed with a scanning electron microscope (SEM) to study the specific characteristics of the circuits or other structures formed on the wafer.

[0003] The similarity between FIB and SEM tools lies in the fact that they each include a charged particle column that generates a beam of charged particles and directs that beam toward the sample. However, as their names suggest, the charged particle beam generated by the FIB column is a focused ion beam, while the charged particle beam generated by the SEM column is a focused electron beam.

[0004] While FIB and SEM tools (and FIB-SEM tools, which include both FIB columns and SEM columns) are frequently used to analyze and otherwise assess the structure within samples, these tools can also be used to etch or deposit material onto samples. For example, according to a technique often called focused ion beam enhanced deposition, or simply FIB-enhanced deposition, a focused ion beam scans the surface of a sample while a gas injection system directs a flow of deposition precursor gas to the scanning area to selectively deposit material with nanometer precision within that area. During the FIB-enhanced deposition process, molecules of the injected gas adhere to the sample surface. As the ion beam scans across the sample area, the energy released by the collisional cascade of bombarding ions causes the surface-adsorbed precursor molecules to dissociate, resulting in a solid deposition on the surface while simultaneously releasing volatile residues. As another example, a deposition gas can be introduced into the sample in the vicinity of where an electron beam scans the sample surface to deposit material beneath an SEM column.

[0005] Although FIB-enhanced deposition has been used in many different situations and applications, there is a continuous search for improved deposition techniques. Summary of the Invention

[0006] Embodiments of this disclosure relate to an improved method and system for charged particle beam enhanced deposition (such as focused ion beam enhanced deposition). Embodiments can be used to increase the deposition rate of charged particle beam enhanced deposition and thereby increase the throughput of processes employing charged particle beam enhanced deposition. While embodiments of this disclosure can be used to increase the rate of material deposition over various types of samples, some embodiments are particularly useful when depositing material over samples such as semiconductor wafers or similar samples.

[0007] In some embodiments, a system is provided for depositing material over a sample in a localized region of the sample. The system may include: a vacuum chamber; a thermal mass disposed outside the vacuum chamber; a sample support configured to hold the sample within the vacuum chamber during sample evaluation processing; a charged particle beam column configured to guide a charged particle beam toward the sample into the vacuum chamber such that the charged particle beam collides with the sample in the deposition region; a gas injection system configured to deliver processing gas to the deposition region of the sample; and a thermally insulating shield spaced apart from the gas injection system and the sample and disposed between the gas injection system and the sample, wherein the thermally insulating shield has high thermal conductivity and low emissivity, and is thermally coupled to the thermal mass to transfer heat radiated from the gas injection system to the thermal mass.

[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 thermal shield may have an emissivity coefficient of 0.1 or less. The system may further include a heating element operatively coupled to heat the gas injection system to above room temperature. The thermal shield may comprise aluminum. The gas injection system may include a gas nozzle including a channel formed through and aligned to allow the focused ion beam to reach the sample through the channel. 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 the thermal mass of the nozzle, and the thermal 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 comprise a high emissivity material. The distal end of the gas nozzle may extend beyond the outer periphery of the thermal shield. The distal end of the gas nozzle may be coated with a low emissivity material. The gas nozzle may comprise stainless steel and the distal end of the gas nozzle may be coated with aluminum. The distal end of the gas nozzle may comprise a low emissivity material. The distal end of the gas nozzle may contain aluminum. The thermal mass may be a chamber cover. The thermal mass may weigh at least 100 kg.

[0009] In some embodiments, a method is provided for depositing material in a deposition region of a sample above a sample using a focused ion beam column. The method may include: positioning the sample within a vacuum chamber such that the deposition region is below the 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 using 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 over the deposition region of the sample to activate molecules of the deposition gas already adhered to the sample surface in the deposition region, and depositing material on the sample within the deposition region. Furthermore, while the focused ion beam scans over the deposition region, the method may utilize a thermally insulating shield comprising a material with high conductivity and low emissivity to shield the sample from heat radiated from the gas injection system.

[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 shield may comprise aluminum. The gas injection system may include a gas nozzle including a channel formed through and aligned to allow the focused ion beam to reach the sample through the channel. 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 that of the nozzle, and the thermal shield may be disposed between the base portion and the sample and between a portion of the nozzle and the sample.

[0011] To better understand the nature and advantages of this disclosure, reference should be made to the following description and accompanying drawings. However, it will be understood that each of the drawings is provided for illustrative purposes only and is not drawn to scale, and is not intended to limit the scope of this disclosure. Furthermore, as a general rule, and unless clearly contrary to the description, where elements in different drawings use the same reference numerals, these elements are substantially the same or at least similar in function or purpose. Attached Figure Description

[0012] Figure 1 This is a simplified schematic illustration of a sample particle beam deposition system;

[0013] Figure 2 This is a simplified schematic illustration of a particle beam deposition system based on some embodiments disclosed herein;

[0014] Figure 3 yes Figure 2 An unfolded view of a portion of the particle beam deposition system shown;

[0015] Figure 4This is a simplified cross-sectional illustration of a part of a sample focusing ion beam system;

[0016] Figure 5A This is a simplified cross-sectional illustration of a sample focusing ion beam system according to some embodiments disclosed herein;

[0017] Figure 5B yes Figure 5A A simplified cross-sectional illustration of a portion of the thermal insulation shield shown;

[0018] Figure 6 This is a simplified description of a gas injection system based on some embodiments disclosed herein;

[0019] Figure 7 This is a flowchart depicting steps associated with a method for depositing material over a sample using a focused ion beam, according to some embodiments; and

[0020] Figure 8 This is a simplified description of a sample that may have material deposited on a portion of the sample according to the embodiments disclosed herein. Detailed Implementation

[0021] Embodiments of this disclosure relate to an improved method and system for charged particle beam enhanced deposition (such as focused ion beam enhanced deposition). Embodiments can be used to increase the deposition rate of charged particle beam enhanced deposition and thereby increase the throughput of processes employing charged particle beam enhanced deposition. In some examples, embodiments can also be used to modify the chemical composition of the deposition material, thereby improving the deposition process.

[0022] Example Focused Ion Beam (FIB) Tool

[0023] To better understand this disclosure, please refer to [the relevant documentation / reference]. Figure 1 , Figure 1 This is a simplified schematic illustration of a previously known focused ion beam (FIB) evaluation system 100. The FIB system 100 can be used for particle-enhanced deposition of various materials over semiconductor wafers, as well as other operations.

[0024] like Figure 1 As shown, system 100 may include a vacuum chamber 110 together with a focused ion beam (FIB) column 120 and other elements. A support element 140 may support a sample 130 (e.g., a semiconductor wafer) within the chamber 110 during processing operations, during which the sample 130 (sometimes referred to herein as the “object” or “sample”) is subjected to a beam of charged particles from the SEM column 120.

[0025] During processing operations, one or more gases may be delivered into chamber 110 via gas injection system 150 for certain operations. For simplicity, in... Figure 1 The gas injection system 150 is shown as a nozzle, but it should be noted that the gas injection system 150 may include a gas reservoir, a gas source, a valve, one or more inlets and one or more outlets, and other elements. In some embodiments, instead of delivering gas to the entire upper surface of the sample, the gas injection system 150 may be configured to deliver gas to a localized area of ​​the sample 130 exposed to the scanning pattern of the charged particle beam. For example, in some embodiments, the gas injection system 150 has a nozzle opening diameter measured in hundreds of micrometers (e.g., between 400 and 500 micrometers), which is configured to deliver gas directly to a relatively small portion of the sample surface covering the scanning pattern of the charged particle beam.

[0026] FIB column 120 is connected to vacuum chamber 110, such that the charged particle beam generated by the FIB column propagates through the vacuum environment formed within vacuum chamber 110 before impacting sample 130. For example, as Figure 1 As shown, the FIB column 120 can generate a focused ion beam 125, which passes through a vacuum environment in the chamber 110 before colliding with the sample 130.

[0027] FIB column 120 can grind sample 130 (e.g., drill indentations therein) to form a cross section by irradiating the sample with charged particle beam 125, and, if desired, smooth the cross section. FIB grinding is typically performed by positioning the sample in a vacuum environment and firing a focused ion beam toward the sample to etch or grind away material. In some cases, the vacuum environment can be purified by a background gas of controlled concentration, which helps control etching rate and quality or helps control material deposition. Accelerating ions can be generated from xenon, gallium, or other suitable elements, and are typically accelerated toward the sample by voltages ranging from 500 volts to 100,000 volts, and more typically from 3,000 volts to 30,000 volts. Beam current is typically in the range from picoamperes to several microamperes, depending on the FIB instrument configuration and application, and pressure is typically controlled at 10 volts in different parts of the system and in different operating modes. -10 Up to 10 -5 Between mbar.

[0028] The grinding process can be accomplished, for example, by: (i) locating the location of interest to be ground in order to remove a portion of the material (e.g., a portion of one or more layers) from the sample; (ii) moving the sample (e.g., via mechanical support element 140) such that the sample is positioned below the field of view of the FIB cell; and (iii) grinding the sample to remove the desired amount of material from the location of interest. The grinding process may include forming a depression in the sample (typically a few micrometers to several hundred micrometers in the lateral dimension).

[0029] Polishing typically involves scanning a charged particle beam back and forth (e.g., in a raster or other scanning mode) over a specific area of ​​the imaged or polished sample. One or more lenses (not shown) coupled to the charged particle beam can implement scanning patterns as known to those skilled in the art. The scanned area is typically a very small portion of the overall area of ​​the sample. For example, the sample may be a semiconductor wafer with a diameter of 150, 200, or 300 mm, and each area scanned on the wafer (i.e., the polished area) may be a rectangular area with a width and / or length measured in micrometers or tens of micrometers. Each iteration (or frame) of the ion beam scanning over the polished area is typically measured in microseconds and removes a very small amount of material (e.g., removing as little as 0.01 atomic layers using a low-i probe (e.g., 10 pA) or up to 1000 atomic layers using a high-i probe (e.g., 1000 nA), allowing the scanning pattern to be repeated thousands or even millions of times to etch holes to the desired depth.

[0030] During the grinding operation, a beam 120 of charged particles generated by the FIB column 120 propagates through a vacuum environment created within the vacuum chamber 110 before impacting the sample 130. The grinding process produces byproducts, such as molecules, atoms, and ions of the material being ground, along with secondary electrons. For example, when ions bombard the sample surface at relatively high energy levels, they can initiate a collisional cascade, transferring momentum and energy from the ions to the sample until the ions stop and are implanted. The momentum and energy transfer during the collisional cascade can lead to atomic dislocations, atomic ionization, and the generation of phonons (thermal). The cascade can reach the sample surface, resulting in the sputtering of atoms with sufficient momentum and energy to escape from the solid sample, and generating secondary ions and electrons as a combination of ionization and sputtering, which also escape from the sample surface. These secondary ions or electrons can be detected by a suitable detector (not shown). The subsequently detected secondary ions or electrons can be used to analyze the properties of the ground layer and structure.

[0031] Despite Figure 1Not illustrated, but the FIB system 100 may include one or more controllers, processors, or other hardware units that control the operation of the system 100 by executing computer instructions stored in one or more computer-readable memories, as is known to those skilled in the art. For example, the computer-readable memory may include solid-state memory (such as random access memory (RAM) and / or read-only memory (ROM), which may be programmable, flash-updatable, and / or similar), disk drives, optical storage devices, or similar non-transitory computer-readable storage media.

[0032] Charged particle enhanced deposition treatment

[0033] Some embodiments of this disclosure can deposit material over a sample positioned on a support 140 by initiating a deposition process below the FIB column 120. For example, in some embodiments, the FIB column 120 can be used in a deposition mode to initiate a focused ion beam enhanced deposition process. For this purpose, a deposition gas can be supplied to the sample 130 by a gas injection system 150, and energy from the FIB column 120 can generate an ion beam 125. The cascade of impacting ions can then activate the deposition gas, resulting in the deposition of material on the sample, which is positioned over a region of the sample over which the ion beam is scanning. Therefore, the deposition that occurs according to this embodiment does not simultaneously occur on the entire surface of the sample being processed or the wafer. Instead, deposition occurs only in general areas of the wafer where the ion beam (by way of a non-limiting example, for xenon plasma, it can have a diameter in the range of 0.5 to 25 micrometers) impacts and when the ion beam scans over those areas of the wafer. Therefore, deposition according to some embodiments can be performed at micrometer-level resolution.

[0034] The deposition rate of materials in this focused ion beam (FIB) enhanced deposition process directly affects the throughput. Therefore, a higher deposition rate can be equated to a higher throughput. During FIB deposition, the deposition rate of material over the sample depends on several different factors, including the energy level of the charged particle beam, the precursor gas used for deposition, the type of material on the sample surface, and the temperature of the sample surface. For example, in FIB enhanced deposition, the molecular adhesion coefficient is one of the parameters that dominates the deposition rate. The adhesion coefficient is a measure of the probability that gaseous molecules adhere to the sample surface after contact. The deposition rate of FIB enhanced deposition increases with increasing adhesion coefficient of the deposition gas. For some precursor gases, the adhesion coefficient is inversely proportional to temperature. That is, increasing temperature decreases the adhesion coefficient, while decreasing temperature increases it.

[0035] For some applications, it is important to heat the gas injection system 150 to well above room temperature (e.g., to about 85 to 95 degrees Celsius in some applications) to avoid deposition of material from the gas flowing through the gas injection system. Such deposition could interfere with gas flow to the grinding area or completely block a portion of the gas injection system, such as the gas nozzle. The gas injection system 150 may include various components made of a metal with relatively high emissivity, such as stainless steel, and may be operatively coupled to a heater element (not shown) that heats the gas injection system to a sufficient temperature to prevent or otherwise reduce deposition within the gas injection system. In some embodiments, in addition to the gas nozzle, the gas injection system may include one or more components that are combined to present a relatively large thermal mass (e.g., at least as large as the thermal mass of the sample itself) in the vicinity of the sample.

[0036] During FIB-enhanced deposition, the heated gas injection system 150 radiates heat toward the sample 130 (as indicated by arrow 155). This radiant heat unduly increases the temperature at the surface of the sample 130 in the region where the ion beam 125 collides with the sample. The increased surface temperature then reduces the adhesion coefficient of the deposition gas introduced to the sample surface by the gas injection system 150, thus unduly reducing the deposition rate.

[0037] Increase the deposition rate of charged particle-enhanced deposition treatment

[0038] To promote higher deposition rates and thus higher throughput, some embodiments of this disclosure may include thermally insulating shielding around a portion of the gas injection system 150 to reduce or prevent heat radiated from the gas injection system from reaching the surface of the sample. Figure 2 This is a simplified schematic illustration of a sample FIB system 200 according to some embodiments disclosed herein. The FIB system 200 includes many of the same components as the system 100 discussed above, such as: a vacuum chamber, a FIB column, a sample support (which supports the sample during processing (e.g., FIB-enhanced deposition) operations), and a gas injection system. Therefore, for ease of reference, similar reference numerals are used for similar components, and descriptions of those similar components are not repeated to avoid unnecessary repetition.

[0039] The FIB system 200 further includes a thermally insulating shield 210 positioned between the gas injection system 150 and the sample 130. The thermally insulating 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 a similarly large thermal mass located away from the sample 130 and positioned outside the vacuum chamber 110. For example, in some embodiments, the FIB system 200 includes a large, heavy chamber cover (not shown) on top of the vacuum chamber 110. The chamber cover, which may be electrically grounded and maintained at or near room temperature, may weigh more than 100 kg, and in some embodiments more than 200 kg, and may be made of a thermally conductive metal, such as stainless steel or aluminum.

[0040] The thermal isolation shield 210 is spaced apart from the gas injection system 150, such that it is positioned between the sample and the gas injection system without physical contact with the gas injection system 150. Therefore, there is no thermal conduction between the thermal isolation shield 210 and the gas injection system 150. Instead, the thermal isolation shield 210 can be in direct physical contact and thermally coupled to a chamber cover (or other thermal mass) maintained at a lower temperature than the gas injection system. In this way, the thermal isolation shield can dissipate heat generated along the gas injection system 150 from the sample 130 to the chamber cover. For example, as... Figure 3 As shown, Figure 3 This is an unfolded view of part of the FIB system 200. Heat radiated from the gas injection system 150 (indicated by arrow 155) is blocked or captured by the thermal isolation shield 210 and transferred away from the sample 130 toward the chamber cover (or a similar large thermal mass located outside the chamber 110 that can be maintained, for example, at room temperature), as indicated by arrow 215. Because the thermal isolation shield 210 has a low emissivity, the heat it re-radiates toward the sample 130 is minimal (and significantly less than the heat radiated by the gas injection system).

[0041] Some FIB systems include a gas injection system in which the gas nozzle has an end positioned directly between the end of the FIB column and the sample. For example, Figure 4A portion of a FIB system 400 is depicted, including a gas injection system 450 comprising a gas nozzle 460 positioned between the distal end of a FIB column 120 and a sample 130. The gas nozzle 460 may be fixed relative to the FIB column 120 in the X and Y planes and movable in the Z plane to allow close approach (e.g., up to 300 micrometers in some embodiments) to the upper surface of the sample 130. As depicted, the gas nozzle 460 includes an orifice or channel 462 formed through the gas nozzle and a nozzle opening 464. The channel 462 allows an ion beam 125 to pass through the gas nozzle and collide with the sample 130 at a location directly below the nozzle. The nozzle opening 464, whose diameter may be larger than that of the channel 462, allows the gas to exit the nozzle 460 at a location adjacent to the surface of the sample 130.

[0042] Figure 5A This is a simplified cross-sectional illustration of a FIB deposition system 500 according to some embodiments. For example... Figure 5A As shown, the FIB deposition system 500 includes a gas injection system 550 similar to the gas injection system 450. This gas injection system includes a gas nozzle 560, which includes 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 at a location adjacent to the upper surface of the sample 130. The gas injection system 550 and the gas nozzle 560 are configured such that the nozzle opening 564 of the gas nozzle 560 can be positioned very close to the sample 130 in the Z-plane (e.g., up to 300 micrometers in some embodiments).

[0043] The FIB deposition system 500 also includes a thermal isolation shield 510, which 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 Figure 5B As shown, Figure 5B This is a simplified cross-sectional illustration of a portion of a thermally insulating shield 510, which includes a bottom wall 512 and side walls 514 surrounding at least three sides of the gas injection system 550. In some embodiments, to allow the gas opening 564 of the gas nozzle 560 to be positioned very close to the sample 130, the thermally insulating shield 510 does not extend between the end of the nozzle 560 and the sample 130. The end of the nozzle 560 represents a relatively small portion of the overall thermal mass of the gas injection system 550. Therefore, not covering the end of the nozzle 560 with the thermally insulating shield 510 does not result in significant heat radiated from the nozzle to the sample 130.

[0044] Furthermore, in some embodiments, at least a portion of the gas nozzle 460 not covered by the thermal insulation shield 510 is coated with a low-emissivity coating (such as aluminum). Thus, for example, in some embodiments, the gas nozzle 560 may be made of a relatively high-emissivity metal (such as stainless steel) coated with a low-emissivity layer (such as aluminum). The aluminum coating can be applied using any known and suitable coating technique (such as electroplating). In yet another embodiment, the gas injection nozzle 460 may be made of a low-emissivity material (such as aluminum).

[0045] While the various embodiments discussed above include gas injection systems with gas nozzles having relatively linear shapes, in other embodiments, the gas nozzles may be curved to include various curves such that there are no right angles in the path the gas travels within the nozzle. An example of a suitable nozzle design is described in commonly assigned U.S. Patent No. 6,992,288, the entire contents of which are incorporated herein by reference.

[0046] For reference Figure 6 , Figure 6 This is a simplified description of a gas injection system 600 according to some embodiments. For example... Figure 6 As shown, the gas injection system 600 may include a gas nozzle 610 and a base portion 620. The gas nozzle 610 includes a channel 612 that allows an ion beam (e.g., ion beam 125) to pass through the gas nozzle and collide with the sample at a location directly below the nozzle, as described above with respect to channel 562. The gas nozzle 610 also includes a nozzle opening 614 at the bottom surface of the gas nozzle in the region of channel 612, which delivers the gas introduced into the gas injection system to the upper surface of the sample.

[0047] The base portion 620 supplies gas to the nozzle portion 610 and may be a relatively large metallic object coupled to a heater (e.g., a resistance heater) to heat the gas injection system 600, including the nozzle 610, to a desired temperature to prevent or otherwise reduce deposition within the gas injection system, as discussed above. In some embodiments, the base portion 620 may be positioned within a vacuum chamber of the FIB tool (such as within vacuum chamber 110) and radiate heat toward the sample being processed. Therefore, some embodiments of this disclosure may include a thermal isolation shield disposed between both the gas nozzle 610 and the base portion 620 to capture heat radiated from both the nozzle 610 and the base portion 620. As described above, the thermal isolation shield may be thermally coupled to a heat sink with a large thermal mass, such as a chamber cover disposed outside the chamber, to dissipate heat from the sample, as described above. The thermal isolation shield 630 occupies an area of... Figure 6The image is depicted with dashed lines, representing the bottom surface of the thermal isolation shield 630, which is positioned below the gas injection system 600 and between the gas injection system and the sample. Figure 6 As shown, the end of the gas nozzle 610 may extend beyond the periphery of the thermal isolation shield 630 in a manner similar to that discussed above with respect to Figure 5. The thermal isolation shield 630 may be made of a high thermal conductivity material with low emissivity as discussed above, and has sidewalls (not shown) extending upward from the bottom surface of the shield toward the chamber cover surrounding the sides of the nozzle 610 and the base portion 620. In some embodiments, the sidewalls of the thermal isolation shield are in physical contact with the chamber cover (which acts as a large thermal mass), allowing the isolation shield to dissipate heat radiated from the gas injection system to the chamber cover.

[0048] Example FIB deposition process

[0049] To further illustrate the implementation of this disclosure, please refer to... Figure 7 and Figure 8 ,in Figure 7 This is a flowchart depicting the steps associated with method 700 according to some implementation methods, and Figure 8 This is a simplified description of sample 800, which may represent sample 130. According to method 700, material can be deposited on sample 800 via charged particle beam enhanced deposition. Method 700 begins by positioning the sample within a processing chamber of a sample evaluation system (block 710). The processing chamber (which may be, for example, chamber 200) may include one or more charged particle beam columns that can operate in deposition mode to deposit material over sample 800 in one or more localized regions. Block 710 may include positioning sample 800 on a sample support (such as support 140) within a vacuum chamber.

[0050] In many cases, sample 800 will include multiple different regions of the material to be deposited. For example, Figure 8 A top view of sample 800 is depicted along with two unfolded views of a specific portion of sample 800. For example, sample 800 may be a 150 mm, 200 mm, or 300 mm semiconductor wafer and may include multiple integrated circuits 810 formed thereon (fifty-two in the depicted example). The integrated circuits 810 may be at an intermediate stage of manufacturing, and method 700 may be used to deposit material over one or more regions 820 of the integrated circuits. For example, Figure 8 Expanded view A depicts multiple regions 820 on which material is deposited, one of the integrated circuits 810 according to the technology described herein. Expanded view B depicts one of those regions 820 in more detail.

[0051] See back Figure 7 The support 140 can be moved to a position where the region in which material will be deposited above the sample (e.g., one of regions 820, referred to herein as the “deposition region”) is placed directly below the tip of the focused ion beam column (step 720). Next, a deposition precursor gas can be injected into the chamber 110 near the deposition region by, for example, a gas injection system 150, which can be heated as discussed above and shielded from radiant heat toward the sample 800 by a thermally insulating shield according to this disclosure.

[0052] During step 730, molecules of the deposition precursor gas adhere to the sample surface based on the adhesion coefficient of the precursor gas. When the gas is delivered to the deposition region and when the deposition region is cooled, a charged particle beam (e.g., an ion beam) can be generated (e.g., 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 a region of the substrate using one or more deflecting lenses (not shown). As discussed above, the cascade of charged particles from beam 125 can activate molecules of the deposition gas adhered to the sample in the deposition region, resulting in the deposition of material on the sample, which is localized to the region of the sample above which the ion beam is scanned. For example, the charged particle beam can dissociate the precursor gas, thereby decomposing the gas into volatile and non-volatile components, with the non-volatile components remaining on the sample surface as the deposition material. Although the implementation can be used to deposit many different types of materials and is not limited to using any particular deposition precursor gas, as a specific example, the deposition precursor gas can be tungsten hexacarbonyl (W(CO)6), which can be dissociated by a charged particle beam to leave a layer of tungsten material deposited on the sample in a local deposition region.

[0053] In practice, steps 740 and 750 can occur almost simultaneously and very quickly, and step 730 can be maintained while steps 750 and 760 are being performed (i.e., the deposited gas can be continuously introduced into the chamber).

[0054] Once the material from the precursor gas has been deposited in the first deposition, if there are additional areas on the sample where material will be deposited (step 760), the sample can be moved via the substrate support to position the next or subsequent deposition area below the tip of the charged particle column (block 720). If there are no additional areas, the deposition process is complete and the sample can be transferred out of system 100 or otherwise processed (step 770).

[0055] Additional Implementation Methods

[0056] For purposes of explanation, the preceding descriptions have used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to those skilled in the art that specific details are not required to practice the described embodiments. Therefore, the foregoing descriptions of the specific embodiments described herein are presented for illustrative and descriptive purposes. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. For example, although the embodiments described above describe a focused ion column as part of a tool having a single column of charged particles, in some embodiments, the focused ion beam column may be positioned within a SEM-FIB tool having both a scanning electron microscope column and a focused ion beam column.

[0057] Furthermore, although different embodiments of this 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 this disclosure. Additionally, it will be apparent to those skilled in the art that many modifications and variations are possible in light of the foregoing teachings. Therefore, it will be understood that the appended claims are intended to cover all such modifications and variations falling within the true spirit of the embodiments of this disclosure.

[0058] Furthermore, any references to methods in the above specification should be modified as necessary to apply to systems capable of executing the methods, and should be modified as necessary to apply to computer program products storing instructions that, upon execution, result in the execution of the methods. Similarly, any references to systems in the above specification should be modified as necessary to apply to methods executable by a system, and should be modified as necessary to apply to computer program products storing instructions executable by a system; and any references to computer program products in the specification should be modified as necessary to apply to methods executable when instructions stored in the computer program product are executed, and should be modified as necessary to apply to systems configured to execute instructions stored in the computer program product.

[0059] Furthermore, although most of the embodiments described in this disclosure can be implemented using electronic components and circuits known to those skilled in the art, such details have not been interpreted to any greater extent than deemed necessary above in order to understand and comprehend the basic concepts of this disclosure and so as not to obscure or distract from its teachings.

Claims

1. A system for depositing material in a local area of a sample above the sample, the system comprising: a vacuum chamber; a thermal mass disposed outside the vacuum chamber; a sample support configured to hold a sample within the vacuum chamber during sample evaluation processing; 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 impacts the sample in a deposition area; a gas injection system configured to deliver a process gas to the deposition area of the sample; and a thermal isolation shield spaced apart from and disposed between the gas injection system and the sample to block or capture heat radiated from the gas injection system toward the sample, wherein the thermal isolation shield has a high thermal conductivity and a low emissivity and is thermally coupled to the thermal mass to transfer heat radiated from the gas injection system to the thermal mass.

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 above room temperature.

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

5. The system of claim 2, wherein the gas injection system comprises a gas nozzle including a passage formed through a distal end of the gas nozzle and aligned to allow the focused ion beam to pass through the passage to the sample.

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

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

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 a distal end of the gas nozzle comprises a low emissivity material.

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

13. The system of claim 1, wherein the thermal mass is a chamber lid.

14. The system of claim 1, wherein the thermal mass weighs at least 100 kg. ​ 15. A method of depositing material over a sample in a deposition region of the sample with a focused ion beam column, the method comprising the steps of: positioning a sample within a vacuum chamber such that the deposition region is located below a field of view of the focused ion beam column; injecting a deposition gas into the vacuum chamber with a gas injection system at a location proximate to the deposition region; generating a focused ion beam with the focused ion beam column and focusing the ion beam within the deposition region of the sample; and scanning the focused ion beam over the deposition region of the sample to activate molecules of the deposition gas adhered to the surface of the sample in the deposition region and deposit material on the sample within the deposition region, wherein the sample is shielded from heat radiated from the gas injection system with a thermally isolating shield comprising a high thermal conductivity, low emissivity material while the focused ion beam is scanned over the deposition region, wherein the thermally isolating shield is disposed between the gas injection system and the sample to block or capture heat radiated from the gas injection system toward the sample.

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

17. The method of depositing material over a sample of claim 15, wherein the thermally isolating shield comprises aluminum.

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

19. The method of depositing material over a sample of claim 15, wherein the gas injection system comprises a base portion and a gas nozzle extending away from the base portion, wherein the base portion has a thermal mass that is substantially greater than a thermal mass of the thermal mass of the gas nozzle, and the thermally isolating shield is disposed between the base portion and the sample and between a portion of the gas nozzle and the sample.

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