Enhanced deposition rate by thermally isolated cover for GIS manipulator

Abstract

A system for depositing a 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 a sample evaluation process; a charged particle beam column configured to direct 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 process gas to a deposition region of the sample; and a thermal isolation shield spaced apart from and disposed between the gas injection system and the sample, where 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.

Description

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

[0002] In the study of electronic materials and the processes used to fabricate such materials into electronic structures, samples of electronic structures may be subjected to microscopic examination for the purposes of failure analysis and device verification. For example, a sample of a wafer such as a silicon, gallium nitride, or other type of wafer including 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 specific characteristics of the circuits or other structures formed on the wafer.

[0003] FIB and SEM tools are similar in that each includes a charged particle column that produces a charged particle beam and directs the beam toward the sample. However, as the names imply, the charged particle beam produced by a FIB column is a focused ion beam, while the charged particle beam produced by a SEM column is a focused electron beam.

[0004] Although FIB and SEM tools (and FIB-SEM tools that include both FIB columns and SEM columns) are often used to analyze and otherwise evaluate structures within a sample, these tools can also be used to etch or deposit materials on the sample. For example, according to a technique often referred to as focused ion beam enhanced deposition, or simply FIB enhanced deposition, a focused ion beam can be scanned over the surface of a sample while a gas injection system directs a flow of deposition precursor gas to the scanned area to selectively deposit material in the scanned area with nanometer precision. During the FIB enhanced deposition process, molecules of the injected gas adhere to the sample surface. As the ion beam scans over an area of ​​the sample, the energy released by the collision cascade of the bombarding ions causes the dissociation of the precursor molecules adsorbed on the surface, resulting in solid deposition on the surface while releasing volatile residues. As another example, a deposition gas can be introduced into the sample near where the electron beam scans the surface of the sample so as to deposit material below the SEM column.

[0005] Although FIB enhanced deposition has been used in many different situations and applications, improved deposition techniques are continually sought. Summary of the invention

[0006] Embodiments of the present 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. Although embodiments of the present disclosure can be used to increase the rate at which material is deposited over a variety of different types of samples, some embodiments are particularly useful when depositing material over samples that are semiconductor wafers or similar samples.

[0007] In some embodiments, a system for depositing a material in a localized region of a sample over a sample is provided. The system may include: a vacuum chamber; a thermal mass disposed outside the vacuum chamber; a sample support configured to hold the sample in the vacuum chamber during sample evaluation processing; a charged particle beam column configured to direct a charged particle beam toward the sample into the vacuum chamber 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 thermal isolation shield spaced from the gas injection system and the sample and disposed between the gas injection system and 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.

[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 isolation 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 to above room temperature. The thermal isolation shield may include aluminum. The gas injection system may include a gas nozzle including a channel formed through the distal end of the nozzle 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 include 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 include stainless steel and the distal end of the gas nozzle may be coated with aluminum. The distal end of the gas nozzle may include a low emissivity material. The distal end of the gas nozzle may comprise aluminum. The thermal mass may be a chamber lid. The thermal mass may weigh at least 100 kg.

[0009] In some embodiments, a method for depositing a material in a deposition region of a sample over a sample using a focused ion beam column is provided. The method may include: positioning the sample in a vacuum chamber so 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 using a gas injection system at a location adjacent to the deposition region; generating a focused ion beam using the focused ion beam column and focusing the ion beam in 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 that have adhered to the surface of the sample in the deposition region, and depositing material on the sample in the deposition region. In addition, while the focused ion beam is scanning over the deposition region, the method may shield the sample from heat radiated from the gas injection system using a thermal isolation shield comprising a high conductivity, 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 isolation shield may include aluminum. The gas injection system may include a gas nozzle including a channel formed through the distal end of the nozzle 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.

[0011] In order to better understand the nature and advantages of the present disclosure, reference should be made to the following description and 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 be a definition of limiting the scope of the present disclosure. In addition, as a general rule, and unless otherwise apparent from the description, where the same reference numerals are used for elements in different figures, these elements are generally the same or at least similar in function or purpose. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0015] Figure 4is a simplified cross-sectional illustration of a portion of a sample focused ion beam system;

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

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

[0018] Figure 6 is a simplified illustration of a gas injection system according to some embodiments disclosed herein;

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

[0020] Figure 8 is a simplified illustration of a sample that may have material deposited over portions of the sample according to embodiments disclosed herein. DETAILED DESCRIPTION

[0021] Embodiments of the present 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 change the chemical composition of the deposited material, thereby improving the deposition process.

[0022] Example Focused Ion Beam (FIB) Tool

[0023] In order to better understand and appreciate the present disclosure, first refer to Figure 1 , Figure 1 is a simplified schematic illustration of a previously known focused ion beam (FIB) evaluation system 100. The FIB system 100 may be used for particle enhanced deposition of various materials on a semiconductor wafer, among other operations.

[0024] like Figure 1 As shown, system 100 may include a vacuum chamber 110 along with a focused ion beam (FIB) column 120 and other components. Support element 140 may support a sample 130 (e.g., a semiconductor wafer) within chamber 110 during processing operations in which sample 130 (sometimes referred to herein as an "object" or "specimen") is subjected to a charged particle beam from SEM column 120.

[0025] During processing operations, one or more gases may be delivered into the chamber 110 via the gas injection system 150 for certain operations. Figure 1 , the gas injection system 150 is shown as a nozzle, but it is 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, among other components. In some embodiments, as opposed to 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 that is exposed to the scan 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 microns (e.g., between 400 and 500 microns), which is configured to deliver gas directly to a relatively small portion of the sample surface that covers the scan pattern of the charged particle beam.

[0026] The FIB column 120 is connected to the vacuum chamber 110 so that the charged particle beam generated by the FIB column propagates through the vacuum environment formed in the vacuum chamber 110 before impinging on the sample 130. Figure 1 As shown, the FIB column 120 can generate a focused ion beam 125 that passes through the vacuum environment of the chamber 110 before colliding with the sample 130.

[0027] The FIB column 120 can grind the sample 130 (e.g., drill a depression therein) to form a cross section by irradiating the sample with a charged particle beam 125, and, if desired, can also smooth the cross section. The FIB grinding process typically operates by positioning the sample in a vacuum environment and firing a focused ion beam toward the sample to etch or grind away material on the sample. In some cases, the vacuum environment can be purged by controlled concentrations of background gases that are used to help control the etching rate and quality or to help control material deposition. The accelerated ions can be generated from xenon, gallium, or other suitable elements, and are typically accelerated toward the sample by a voltage in the range of from 500 volts to 100,000 volts, and more typically falling in the range of from 3,000 volts to 30,000 volts. The beam current is typically in the range of from picoamps to several microamps, depending on the FIB instrument configuration and application, and the pressure is typically controlled in different parts of the system and in different operating modes. -10 Up to 10 -5 mbar.

[0028] The milling process can be accomplished, for example, by (i) locating a location of interest that should be milled to remove a portion of material (e.g., a portion of one or more layers) from the sample, (ii) moving the sample (e.g., via mechanical support element 140) so that the sample is below the field of view of the FIB unit, and (iii) milling the sample to remove the desired amount of material in the location of interest. The milling process can include forming a depression (typically a few microns to a few hundred microns in lateral dimension) in the sample.

[0029] The grinding process typically includes 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 ground sample. One or more lenses (not shown) coupled to the charged particle column can implement a scanning pattern 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 can be a semiconductor wafer with a diameter of 150, 200, or 300 mm, and each area scanned on the wafer (i.e., the ground area) can be a rectangular area with a width and / or length measured in microns or tens of microns. Each iteration (or frame) in which the ion beam scans over the ground area is typically measured in microseconds, and a very small amount of material is removed (e.g., using a low i probe (e.g., 10 pA) to remove as little as 0.01 atomic layers or using a high i probe (e.g., 1000 nA) to remove up to 1000 atomic layers), so that the scanning pattern is repeated thousands or even millions of times to etch the hole to the desired depth.

[0030] During the grinding operation, the charged particle beam 120 generated by the FIB column 120 propagates through the vacuum environment formed in the vacuum chamber 110 before hitting the sample 130. The grinding process produces byproducts, such as molecules, atoms and ions of the material being ground together with secondary electrons. For example, when ions bombard the sample surface with relatively high energy levels, the ions can start a collision cascade, transferring momentum and energy from the ions to the sample until the ions stop and are injected. The momentum and energy transfer during the collision cascade can cause atomic dislocation, atomic ionization and phonon (heat) generation. The cascade can reach the sample surface, causing atoms with sufficient momentum and energy to sputter to escape the solid sample, and produce secondary ions and electrons as a combination of ionization and sputtering, which also escape the sample surface. Secondary ions or secondary electrons can be detected by an appropriate detector (not shown). The secondary ions or secondary electrons detected subsequently can be used to analyze the characteristics of the grinding layer and structure.

[0031] Despite Figure 1Although not shown in the figure, 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 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 the like), a disk drive, an optical storage device, or a similar non-transitory computer-readable storage medium.

[0032] Charged Particle Enhanced Deposition Processing

[0033] Some embodiments of the present disclosure may 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 may be used in a deposition mode to initiate a focused ion beam enhanced deposition process. To this end, a deposition gas may be supplied to the sample 130 by a gas injection system 150 and energy from the FIB column 120 may generate an ion beam 125. The cascade of impinging ions may then activate the deposition gas, thereby causing material to be deposited on the sample, the material being positioned to the region of the sample over which the ion beam is scanned. Thus, deposition occurring according to such an embodiment does not occur simultaneously over the entire surface of the sample or wafer being processed. Instead, deposition occurs only when the ion beam (which, as a non-limiting example, may have a diameter in the range of 0.5 to 25 microns for a xenon plasma) impinges in a general region on the wafer and when the ion beam is scanned over those regions of the wafer. Thus, deposition according to some embodiments may be performed at micron-level resolution.

[0034] The rate at which material is deposited in such a focused ion beam (FIB) enhanced deposition process has a direct impact on the throughput of the process. Therefore, a higher deposition rate can be equivalent to a higher throughput. During a FIB deposition process, the rate at which material is deposited over a sample depends on several different factors, including the energy level of the charged particle beam, the precursor gas used for the deposition process, the type of material on the sample surface, and the temperature of the sample surface. For example, in a FIB enhanced deposition process, the molecular adhesion coefficient is one of the parameters that dominates the deposition rate. The adhesion coefficient is a measure of the probability that an airborne molecule adheres to the sample surface after contact. The deposition rate of a FIB enhanced deposition process increases with an increase in the adhesion coefficient of the deposition gas. For some precursor gases, the adhesion coefficient is inversely proportional to the temperature. That is, an increase in temperature reduces the adhesion coefficient, while a decrease in temperature increases the adhesion coefficient.

[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) in order to avoid deposition of material from the gas flowing through the gas injection system, which deposition could interfere with the flow of gas to the milling area or completely clog a portion of the gas injection system, such as a gas nozzle. The gas injection system 150 may include various components made of a metal with a relatively high emissivity (such as stainless steel), and the gas injection system may be operably 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 near the sample (e.g., a thermal mass at least as large as the sample itself).

[0036] 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 unduly increase 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 can then reduce the sticking coefficient of the deposition gas introduced to the sample surface by the gas injection system 150, thereby unduly reducing the deposition rate.

[0037] Increasing the deposition rate of charged particles to enhance the deposition process

[0038] To facilitate higher deposition rates, and therefore higher processing rates, some embodiments of the present disclosure may include a thermal isolation shield surrounding portions 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 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, including, for example, a vacuum chamber, a FIB column, a sample support (which can support the sample during processing (e.g., FIB enhanced deposition) operations), and a gas injection system. Therefore, for ease of reference, like reference numerals are used for like components, and to avoid unnecessary repetition, the description of those like components is not repeated.

[0039] The FIB system 200 further includes a thermal isolation shield 210 positioned between the gas injection system 150 and the sample 130. The thermal isolation shield 210 can 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 can be thermally coupled to a chamber lid or a similar large thermal mass that is remote from the sample 130 and disposed outside the vacuum chamber 110. For example, in some embodiments, the FIB system 200 includes a large, heavy chamber lid (not shown) on top of the vacuum chamber 110. The chamber lid, which can be electrically grounded and maintained at or near room temperature, can weigh more than 100 kg, and in some embodiments more than 200 kg, and can 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 the thermal isolation shield is positioned between the sample and portions of the gas injection system without being in physical contact with the gas injection system 150. Thus, 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 with and thermally coupled to a chamber lid (or other thermal mass) that is 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 lid. For example, as Figure 3 As shown, Figure 3 , which is an expanded view of a portion of FIB system 200, heat radiated from gas injection system 150 (indicated by arrow 155) is blocked or captured by thermal isolation shield 210 and transported away from sample 130 toward the chamber lid (or a similar large thermal mass located outside chamber 110 that may be maintained at, for example, room temperature), as indicated by arrow 215. Because thermal isolation shield 210 has a low emissivity, the heat it re-radiates toward 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 a tip positioned directly between the end of the FIB column and the sample. Figure 4A portion of a FIB system 400 is depicted that includes a gas injection system 450 that includes a gas nozzle 460 positioned between the distal end of the FIB column 120 and the sample 130. The gas nozzle 460 can be in a fixed relationship relative to the FIB column 120 in the X and Y planes and can be moved in the Z plane to allow the nozzle to be in close proximity (e.g., up to 300 microns in some embodiments) to the upper surface of the sample 130. As depicted, the gas nozzle 460 includes a hole or channel 462 formed through the gas nozzle and a nozzle opening 464. The channel 462 allows the 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, which can have a diameter greater than the diameter 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 is a simplified cross-sectional illustration of a FIB deposition system 500 according to some embodiments. Figure 5A As shown, the FIB deposition system 500 includes a gas injection system 550 similar to the gas injection system 450, the gas injection system including a gas nozzle 560, the gas nozzle including a channel 562 that allows the ion beam to pass through the gas injection nozzle and collide with the sample 130 at a position directly below the nozzle, and a nozzle opening 564 that allows the gas to exit the nozzle 560 at a position adjacent to the upper surface of the sample 130. The gas injection system 550 and the gas nozzle 560 are configured so 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., in some embodiments, as close as 300 microns).

[0043] The FIB deposition system 500 also includes a thermal isolation 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, Figure 5B As shown, Figure 5B 5 is a simplified cross-sectional illustration of a portion of a thermal isolation shield 510, which includes a bottom wall 512 and side walls 514 surrounding at least three sides of a gas injection system 550. To allow the gas opening 564 of the gas nozzle 560 to be positioned very close to the sample 130, in some embodiments, the thermal isolation 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 thermal isolation shield 510 does not result in significant heat radiating from the nozzle to the sample 130.

[0044] In addition, some embodiments of the gas nozzle 460 that is not covered by the thermal isolation shield 510 is coated with a low emissivity coating (such as aluminum). Thus, for example, in some embodiments, the gas nozzle 560 can 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 other embodiments, the gas injection nozzle 460 can be made of a low emissivity material (such as aluminum).

[0045] Although various embodiments discussed above include gas injection systems having relatively linearly shaped gas nozzles, in other embodiments, the gas nozzles may be curved to include various curves so that no right angles exist in the path that the gas traverses within the nozzle. An example of a suitable nozzle design is described in commonly assigned U.S. Pat. No. 6,992,288, the entire contents of which are incorporated herein by reference.

[0046] Reference Figure 6 , Figure 6 is a simplified illustration of a gas injection system 600 according to some embodiments. 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 the channel 612 that delivers 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 can be a relatively large metal object that is coupled to a heater (e.g., a resistive heater) to heat the gas injection system 600 including the nozzle 610 to a desired temperature for preventing or otherwise reducing deposition within the gas injection system, as discussed above. In some embodiments, the base portion 620 can be positioned within a vacuum chamber of a FIB tool (such as within the vacuum chamber 110) and radiate heat toward a sample being processed. Therefore, some embodiments of the present disclosure may include a thermal isolation shield disposed between the gas nozzle 610 and the base portion 620 to capture heat radiated from the nozzle 610 and the base portion 620. As described above, the thermal isolation shield can be thermally coupled to a heat sink having a large thermal mass, such as a chamber lid disposed outside the chamber, to dissipate heat from the sample, as described above. The thermal isolation shield 630 occupies an area of Figure 6600 are depicted in dashed lines, which represent the bottom surface of the thermal isolation shield 630, which is positioned below the gas injection system 600 and disposed between the gas injection system and the sample. Figure 6 As shown, the end of the gas nozzle 610 can extend beyond the perimeter of the thermal isolation shield 630 in a manner similar to that discussed above with respect to FIG. 5. The thermal isolation shield 630 can be made of a highly thermally conductive material with low emissivity as discussed above, and has sidewalls (not shown) extending from the bottom surface of the shield upward toward the chamber lid surrounding the nozzle 610 and the sides of the base portion 620. In some embodiments, the sidewalls of the thermal isolation shield are in physical contact with the chamber lid (acting as a large thermal mass), which allows the isolation shield to dissipate heat radiated from the gas injection system to the chamber lid.

[0048] Example FIB Deposition Process

[0049] To further illustrate the embodiments of the present disclosure, refer to Figure 7 and Figure 8 ,in Figure 7 is a flowchart depicting steps associated with method 700 according to some embodiments, and Figure 8 is a simplified illustration of a sample 800 that may represent sample 130. According to method 700, a material may be deposited on sample 800 via a charged particle beam enhanced deposition process. Method 700 begins by positioning a 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 may be operated in a deposition mode to deposit material in one or more localized regions above sample 800. 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 material to be deposited. For example, Figure 8 A top view of sample 800 is depicted along with two expanded views of specific portions of sample 800. For example, sample 800 may be a 150 mm, 200 mm, or 300 mm semiconductor wafer and may include a plurality of integrated circuits 810 formed thereon (fifty-two in the depicted example). Integrated circuits 810 may be in an intermediate stage of fabrication 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 of 810 depicts a plurality of regions 820 over which material may be deposited of one of the integrated circuits 810 in accordance with the techniques described herein. Expanded view B depicts one of those regions 820 in greater detail.

[0051] Return to see Figure 7 , the support 140 can be moved to a position that places the region where material is to be deposited above the sample (e.g., one of the regions 820, referred to herein as a "deposition region") directly below the tip of the focused ion beam column (step 720). Next, a deposition precursor gas can be injected into the chamber 110 at a location proximate to the deposition region by, for example, a gas injection system 150 (step 730), which can be heated as discussed above and shielded from radiant heat toward the sample 800 by a thermal isolation shield according to the present disclosure.

[0052] During step 730, molecules of the deposition precursor gas adhere to the sample surface according to the adhesion coefficient of the precursor gas. When the gas is delivered to the deposition area and when the deposition area is cooled, a charged particle beam (e.g., an ion beam) can be generated (e.g., step 740) and the charged particle beam can be focused and scanned over an area 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 using one or more deflection lenses (not shown). As discussed above, the cascade of charged particles from beam 125 can activate molecules of the deposition gas that adhere to the sample in the deposition area, thereby causing material to be deposited on the sample, which is located in the area of ​​the sample over 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, wherein the non-volatile components remain on the sample surface as deposition material. Although embodiments may be used to deposit many different types of materials and are not limited to use with any particular deposition precursor gas, as a specific example, the deposition precursor gas may be tungsten hexacarbonyl (W(CO)6), which may be dissociated by a charged particle beam, thereby leaving a layer of tungsten material deposited on the sample within a localized deposition area.

[0053] In actual practice, steps 740 and 750 may occur substantially simultaneously and very quickly, and step 730 may be maintained while steps 750 and 760 are performed (ie, deposition gas may continue to be 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 the material is to be deposited (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). If there are no additional areas, the deposition process is complete and the sample can be transferred out of the system 100 or otherwise processed (step 770).

[0055] Additional Implementations

[0056] For the purpose of explanation, the previous description uses 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 description of the specific embodiments described herein is presented for illustration and description purposes. They are not intended to be exhaustive or to limit the embodiments to the precise form disclosed. For example, although the embodiments described above describe the focused ion column as part of a tool having a single charged particle column, in some embodiments, the focused ion beam column can be positioned within a SEM-FIB tool having both a scanning electron microscope column and a focused ion beam column.

[0057] In addition, although different embodiments of the present disclosure are disclosed above, the specific details of a particular embodiment may be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present disclosure. In addition, it will be apparent to those skilled in the art that many modifications and variations are possible in view of the above teachings. Thus, it will be understood that the appended claims are intended to cover all such modifications and variations that fall within the true spirit of the embodiments of the present disclosure.

[0058] Furthermore, any reference in the above specification to a method shall apply mutatis mutandis to a system capable of performing the method, and shall apply mutatis mutandis to a computer program product storing instructions which, upon execution, result in the performance of the method. Similarly, any reference in the above specification to a system shall apply mutatis mutandis to a method executable by the system, and shall apply mutatis mutandis to a computer program product storing instructions which, upon execution, result in the performance of the method. And any reference in the specification to a computer program product shall apply mutatis mutandis to a method executable when the instructions stored in the computer program product are executed, and shall apply mutatis mutandis to a system configured to perform the instructions stored in the computer program product.

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

Claims

1. A system for depositing a material over a sample in a localized region of the sample, the system comprising: Vacuum chamber; a thermal mass disposed outside the vacuum chamber; a sample support configured to retain 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 so that the charged particle beam collides with the sample in a deposition region; The gas injection system is configured to deliver a process gas to the deposition region of the sample; and a thermal isolation shield spaced apart from and disposed between the gas injection system and the sample, wherein the thermal isolation 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. 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 above room temperature. The system of claim 1 , wherein the thermal isolation shield comprises aluminum.

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

6. The system of claim 1 , wherein the gas injection system comprises a base portion and a nozzle extending away from the base portion, wherein the base portion has a thermal mass significantly greater than a thermal mass of the nozzle, and the thermal 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 perimeter 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. 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 the distal end of the gas nozzle comprises aluminum.

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

14. The system of any one of claims 1 to 13, wherein the thermal mass is a chamber lid.

15. A method of depositing material in a deposition region over a sample using a focused ion beam column, the method comprising the steps of: Positioning the sample within the vacuum chamber so 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 using a gas injection system at a location adjacent to the deposition region; generating a focused ion beam using the focused ion beam column and focusing the ion beam within the deposition region of the sample; as well as scanning the focused ion beam over the deposition region of the sample to activate molecules of the deposition gas adhered to the sample surface in the deposition region and deposit material on the sample in the deposition region, Wherein, while the focused ion beam is scanned over the deposition area, a thermal isolation shield comprising a high conductivity, low emissivity material is used to shield the sample from heat radiated from the gas injection system.

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

18. The method of claim 15, wherein the thermal isolation shield comprises aluminum.

19. A method for depositing material above a sample according to claim 15, wherein the gas injection system includes a gas nozzle, the gas nozzle including a passage formed through a distal end of the nozzle and aligned to allow the focused ion beam to reach the sample through the channel.

20. A method for depositing material over a sample according to any one of claims 15 to 19, wherein the gas injection system includes a base portion and a nozzle extending away from the base portion, wherein the base portion has a thermal mass significantly greater than the thermal mass of the nozzle, and the thermal shield is disposed between the base portion and the sample and between a portion of the nozzle and the sample.

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