Mixed gas type plasma source system

Abstract

An ion beam system, the ion beam system comprising a plasma source tube defining a plasma source chamber; a first gas reservoir containing a first gas; a second gas reservoir containing a second gas; a first controller fluidly coupled to the first gas reservoir and configured to control a first flow rate of the first gas; and a second controller fluidly coupled to the second gas reservoir and configured to control a second flow rate of the second gas. The system also includes a first capillary constriction including a first end fluidly coupled to the first controller and a second end fluidly coupled to the plasma source chamber, and a second capillary constriction including a second end fluidly coupled to the second controller. The second capillary constriction includes a third end fluidly coupled to the second controller and a fourth end fluidly coupled to the plasma source chamber, wherein the first capillary constriction and the second capillary constriction are different.

Description

BACKGROUND OF THE INVENTION

[0001] Charged particle beam systems are used in a variety of applications, including the fabrication, repair, and inspection of microdevices such as integrated circuits, magnetic recording heads, and lithography masks. In one type of charged particle beam system, ions are generated by ionizing a gas in an ion plasma source. These ions are then directed in a beam towards a sample for processing or imaging steps and to physically alter the sample. The ion species used for this purpose can be customized for a particular sample or process by changing the gas species ionized in the plasma source. Some samples or processes require a mixture of multiple unique ion species, which dictates a mixture of multiple unique gas species in the plasma source. There is a desire for a new charged particle beam system that optimizes such gas mixing. SUMMARY OF THE INVENTION

[0002] One aspect of the present disclosure provides an ion beam system. The ion beam system further includes a plasma source tube defining a plasma source chamber. The system further includes a first gas reservoir containing a first gas and a second gas reservoir containing a second gas. The system further includes a first controller and a second controller, the first controller being fluidly coupled to the first gas reservoir and configured to control a first flow rate of the first gas, the second controller being fluidly coupled to the second gas reservoir and configured to control a second flow rate of the second gas. The system further includes a first capillary constriction and a second capillary constriction, the first capillary constriction including a first end fluidly coupled to the first controller and a second end fluidly coupled to the plasma source chamber, the second capillary constriction including a third end fluidly coupled to the second controller and a fourth end fluidly coupled to the plasma source chamber, wherein the first capillary constriction and the second capillary constriction are different.

[0003] Another aspect of the present disclosure provides an ion beam system. The ion beam system further includes a plasma source tube defining a plasma source chamber. The system further includes a first gas reservoir containing a first gas species and a second gas reservoir containing a second gas species. The system further includes a first controller fluidly coupled to the first gas reservoir and configured to control a first flow rate of the first gas species. The system further includes a first capillary constriction including a first end fluidly coupled to the first controller and a second end fluidly coupled to the plasma source chamber. The system further includes a computer system in communication with the first controller and configured to provide instructions for operating the first controller.

[0004] Another aspect of the present disclosure provides a non-transitory computer-readable storage medium storing computer-readable instructions of a program. The non-transitory computer-readable storage medium further includes instructions to direct a first controller to open a first variable outlet pressure valve to release a first gas from a first gas reservoir at a first flow rate through a first capillary constriction into a plasma source chamber defined in a plasma source tube. The medium further includes instructions to direct a second controller to open a second variable outlet pressure valve to release a second gas from a second gas reservoir at a second flow rate through a second capillary constriction into the plasma source chamber such that the first gas and the second gas are mixed in the plasma source chamber, wherein the second capillary constriction is different from the first capillary constriction. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A further understanding of the nature and advantages of various embodiments may be realized by reference to the following drawings. In the drawings, like components or features may have the same reference numeral. Additionally, various components of the same type may be distinguished by following the reference numeral with a dash and a second numeral used to distinguish among similar components. If only the first reference numeral is used in the specification, the description applies to any one of the similar components having the same first reference numeral regardless of the second reference numeral.

[0006] Figure 1 A simplified cross-sectional view of an example charged particle system is depicted.

[0007] Figure 2A A simplified cross-sectional view of an example charged particle system according to an embodiment of the present disclosure is depicted.

[0008] Figure 2B Depicts a charged particle system for exhausting gas from a plasma source chamber Figure 2A of the present disclosure.

[0009] Figure 3 A diagram depicting a gas flow path of a plasma source system according to an embodiment of the present disclosure is shown.

[0010] Figure 4 A flowchart depicting a process for adjusting a ratio of gas species in a gas mixture using a plasma source system according to an embodiment of the present disclosure is shown.

[0011] Figure 5 A flowchart depicting a process for mixing gases in a plasma source chamber according to an embodiment of the present disclosure is shown.

[0012] Figure 6 A flowchart depicting a process for exhausting gas from a plasma source chamber according to an embodiment of the present disclosure is shown.

[0013] Figure 7 FIG. Figure 7 depicts a flowchart showing a process for providing instructions to a plasma source system for a mixed gas according to an embodiment of the present disclosure.

[0014] Figure 8 FIG. Figure 8 depicts a block diagram of an example computer system that can be used with the systems and methods according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0015] An ion beam system is a charged particle beam system for altering a sample (e.g., by milling). Specifically, a focused ion beam (FIB) mills by physically removing atoms and molecules from the surface of the sample through a process called physical sputtering. An FIB system typically operates by directing a focused ion beam onto the surface of the sample (such as a raster pattern). In one example, these ions can be extracted from a plasma source and accelerated and focused onto the sample using a series of apertures and electrostatic lenses. Specifically, these plasma sources ionize a gas or gas mixture in a plasma source chamber and extract ions to form a beam focused on the sample. A particular material of the sample or the process being performed on that material may require a specific ratio of process gas mixture in order to produce a mixed-species ion beam that optimally mills the sample. Providing a specific ratio of gas species in the gas mixture for each particular sample can be challenging.

[0016] One method of providing a gas mixture includes providing a pre-mixed gas mixture to the plasma source. While this may be feasible in cases where the pre-mixed gas mixture includes the exact ratio of gases for extracting an optimal ion beam to mill the sample (e.g., to mill through a non-uniform or varying type of material layer), problems can arise when the pre-mixed gas mixture does not include this specific ratio of gases. Specifically, since the gas mixture is pre-mixed, the gas ratio in the gas mixture cannot be dynamically changed (e.g., the gas ratio in the gas mixture cannot change as the sample is being milled). Thus, using a pre-mixed gas mixture provides less flexibility.

[0017] Another method of providing a gas mixture can include mixing gases at a high-pressure gas inlet (e.g., greater than 1 bar) located just outside the plasma chamber and using a constriction to introduce the gas mixture into the plasma source chamber. However, if mixing is performed at high pressure prior to the constriction, it may be difficult to control and regulate the desired partial pressure of each gas within the plasma unit. Additionally, due to manufacturing variability, the constriction region (e.g., formed by precisely curling a tube) can be different between each system, which can result in the constriction having an irregular cross-sectional shape and making it difficult to consistently control the pressure with this method. Inconsistencies in leak rates can be seen between different units or even over time within the same unit. Further still, changing the gas mixture can take a long time (e.g., about 10 minutes) and result in unnecessary waste of expensive gases, as the high-pressure gas from the entire gas supply line must be removed to provide a new gas mixture. Thus, using such a high-pressure drop for the constriction can be difficult, inconsistent, and expensive.

[0018] The present disclosure provides a plasma source system that includes controllers, each of which can selectively and individually control the delivery of a particular gas species. Specifically, each controller controls the pressure or differential flow rate of each gas species being mixed into the gas mixture such that the components of the gas mixture can be more dynamically and accurately controlled to accommodate different sample materials. The present disclosure also includes a capillary constriction that is fluidly separate from the gas supply line such that the gas within the capillary constriction can be evacuated without the need to evacuate the gas supply line. This can minimize gas waste and save costs. The capillary constriction can also be smaller than a conventional gas supply line to further minimize gas waste and save costs by evacuating less gas than a conventional plasma source system.

[0019] While the remainder of this specification will conventionally refer to FIB systems, those skilled in the art will readily understand that the technology is not limited thereto. The design of the present invention can be used with other types of charged particle microscopes, such as scanning electron microscopes (SEM), transmission electron microscopes (TEM), scanning transmission electron microscopes (STEM), dual-beam systems including an ion beam source and an electron beam source, reflection electron microscopes (REM), circuit edit microscopes, etc. Thus, the present disclosure and claims should not be considered limited to any particular example microscope discussed, but can be broadly used with any number of charged particle microscopes that can exhibit some or all of the electrical or chemical properties of the example discussed.

[0020] Figure 1Depicts an example charged particle system 100 (e.g., an FIB system). For simplicity, additional details regarding the charged particle system, such as the focusing column and the sample chamber, are not shown. Gas is supplied from an external gas supply line 104 through a gas filter 106 to a plasma source chamber 102 within a plasma source tube 103 and is then supplied to a tube 108 having a constriction 110. Energy is fed from a radio frequency (RF) power source 113 into the plasma source chamber 102 through an antenna coil 114, and ions are extracted through an extractor electrode 120 via a source electrode hole 116 in a source electrode 118.

[0021] Multiple gas sources, such as a first gas reservoir 130a, a second gas reservoir 130b, a third gas reservoir 130c, and a fourth gas reservoir 130d, supply gas into the gas supply line 104 through respective valves 131a, 131b, 131c, 131d (e.g., pressure regulators, bypass valves, etc.). Each of the gas reservoirs 130a, 130b, 130c, 130d may include a gas species for generating plasma (e.g., oxygen, xenon, krypton, argon, nitrogen, hydrogen, etc.). The gas flows from the gas reservoirs 130a, 130b, 130c, 130d in a downstream direction through the constriction 110 in the tube 108 into the plasma source chamber 102 and exits through the hole 116 in the source electrode 118. A pump 122 may be connected to the gas supply line 104 through a valve 123 and may be activated to remove gas from the plasma source chamber 102 through the tube 108 and the gas supply line 104. An ion getter pump (not shown) extracts gas from the plasma source chamber 102 through the source electrode hole 116. A beam voltage source 132 supplies a high voltage to the plasma in the chamber 102, and an extraction voltage source 134 supplies a voltage to the extractor electrode 120. The extracted ions or electrons are focused towards a sample chamber (not shown) accommodating a sample by using a focusing electrode 136. To remove gas from the interior of the plasma source chamber 102, the valve 123 may be activated to pump the gas out of the gas supply line 104 and the plasma source tube 103 in an upstream direction and out of the source electrode hole 116 from a main chamber vacuum pump (not shown) in a downstream direction.

[0022] The tube 108 may facilitate a calibrated leak from the gas supply line 104 to the plasma source chamber 102. Specifically, the portion of the plasma source system 100 upstream of the tube 108 may be pressurized to be greater than the portion of the plasma source system 100 downstream of the tube 108 (e.g., in the plasma source chamber 102), such that gas flows downstream from the gas supply line 104 to the plasma source chamber 102. Additionally, the tube 108 may define the constriction 110 to have a specific diameter (e.g., less than about 1 mm, such as about 5 to 10 microns), such that gas flows into the plasma source chamber 102 at a desired velocity.

[0023] As described above, because the various gas flow rates of the gas are mixed in the large gas supply line 104 before reaching the tube 108, it may be difficult to accurately control the partial pressure of each gas species in the gas mixture just upstream of the tube 108, and thus difficult to accurately control the flow rate. Additionally, because the constriction 110 requires an extremely precise diameter to ensure that the gas enters the plasma source chamber 102 at a precise flow rate, the diameter can vary with the manufacturer and may not be consistent. Therefore, it is even more difficult to control the pressure of the gas entering the plasma source chamber 102. Finally, when changing the gas mixture, the entire gas supply line 104 (e.g., the gas in the gas supply line 104 between valves 123, 131a, 131b, 131c, 131d to the tube 108) must be evacuated, resulting in gas waste and a need for long evacuation times.

[0024] These problems are solved by the described plasma source system with a separate controller and different methods of introducing a gas mixture into the plasma source chamber of the plasma source system and evacuating the gas mixture from the plasma source chamber of the plasma source system. For example, Figure 2A and Figure 2B FIG. depicts an example charged particle system 200 that includes a plasma source system 280 and a computer system 290 that communicates with the plasma source system 280 to provide instructions for operating the plasma source system 280 (similar to Figure 8 the computer system 810 shown). As described above, no additional details of the charged particle system 200, such as the focusing column and the sample chamber, are shown. It should be understood that features that end with reference numerals similar to those discussed above are similar, unless otherwise indicated below.

[0025] The plasma source system 280 includes a first gas reservoir 230a and a second gas reservoir 230b that are fluidly coupled to the chamber body 260 via respective gas valves 231a, 231b (e.g., pressure regulators, bypass valves, etc.), gas supply lines 204a, 204b, and controllers 240a, 240b. The chamber body 260 defines an internal volume 262 that houses a first capillary constriction 250a, a second capillary constriction 250b, a bypass manifold 252 that defines a bypass chamber 254, a plasma source tube 203 that defines a plasma source chamber 202, and an antenna coil 214. Each of the gas reservoirs 230a, 230b may include a respective gas supply line 204a, 204b, pump valve 223a, 223b, pump 222a, 222b, gas valve 231a, 231b, controller 240a, 240b, and capillary constriction 250a, 250b. Although only two gas reservoirs 230a, 230b are depicted, in other embodiments, any number of gas reservoirs may be present, such as one, three, four, five, etc. In these examples, each of the gas reservoirs may include a respective gas supply line, pump, gas valve, controller, and capillary constriction. The respective gas reservoirs 230a, 230b, gas supply lines 204a, 204b, pump valves 223a, 223b, pumps 222a, 222b, controllers 240a, 240b, and capillary constrictions 250a, 250b may be fluidly coupled to each other such that gas can flow from the gas reservoirs 230a, 230b through the gas supply lines 204a, 204b, controllers 240a, 240b, and capillary constrictions 250a, 250b to mix in the plasma source chamber 202.

[0026] Figure 2A Gas is depicted as flowing downstream from the gas reservoirs 230a, 230b through the gas supply lines 204a, 204b, controllers 240a, 240b, capillary constrictions 250a, 250b, bypass chamber 254, and into the plasma source chamber 202 to generate plasma 255. The ion species ratio of the ion beam extracted from the plasma 255 can be measured by a measurement unit 275 (e.g., residual gas analyzer, mass spectrometer, etc.) located on the sample, in the ion beam column, etc. Figure 2B Depicted is evacuating the gas used to generate plasma 255 by indicating the bypass actuator 242 to move the bypass manifold 252, as further described below. As discussed above, in other examples of plasma sources, it may be difficult, inconsistent, and wasteful to control the pressure and gas flow rate to obtain a more precise gas mixture composition. The capillary constrictions 250a, 250b and the controllers 240a, 240b address these problems.

[0027] Controllers 240a, 240b can be fluidly coupled between gas supply lines 204a, 204b and capillary constrictions 250a, 250b such that controllers 240a, 240b control the flow rate of gas entering capillary constrictions 250a, 250b from gas supply lines 204a, 204b. This in turn can control the flow rate of gas entering bypass chamber 254 and subsequently entering plasma source chamber 202. For example, controllers 240a, 240b can include variable outlet pressure valves that are capable of controlling the pressure from gas supply lines 204a, 204b to capillary constrictions 250a, 250b and providing a variable flow rate. In this way, controllers 240a, 240b can adjust the partial pressure of each gas species in the gas mixture used to generate plasma 255 to adjust the composition of the gas mixture. Controllers 240a, 240b allow for the dynamic adjustment of the gas mixture (e.g., in real time when ions are being extracted) without the need to purge the gas mixture. Controllers 240a, 240b can also include pressure sensors to detect the gas pressure in gas supply lines 204a, 204b and / or capillary constrictions 250a, 250b. Controllers 240a, 240b can be instructed to release gas into capillary constrictions 250a, 250b at least in part due to the pressure measurements detected by the pressure sensors.

[0028] In some embodiments, controllers 240a, 240b can control the pressure both upstream and downstream of controllers 240a, 240b. For example, controllers 240a, 240b can control the pressure downstream of controllers 240a, 240b by controlling a safety valve to allow gas to flow from gas supply lines 204a, 204b into capillary constrictions 250a, 250b. Controllers 240a, 240b can control the pressure upstream of controllers 240a, 240b by controlling bleed port valves 244a, 244b included in controllers 240a, 240b. Bleed port valves 244a, 244b can be in fluid communication with a vacuum source (e.g., internal volume 262, discussed below) to allow gas from gas supply lines 204a, 204b and capillary constrictions 250a, 250b to flow through bleed port valves 244a, 244b and toward the vacuum source. For example, bleed port valves 244a, 244b can allow gas in gas supply lines 204a, 204b to flow downstream through bleed port valves 244a, 244b and be evacuated to the vacuum source, while gas in capillary constrictions 250a, 250b can flow upstream in capillary constrictions 250a, 250b and through bleed port valves 244a, 244b and be evacuated to the vacuum source.

[0029] The controllers 240a, 240b can control the bleed port valves 244a, 244b such that the controllers 240a, 240b can vent the gas in the gas supply lines 204a, 204b. In this way, the gas in the gas supply lines 204a, 204b can be vented at one end by the controllers 240a, 240b and at the other end by the pumps 222a, 222b to accelerate the gas venting of the gas supply lines 204a, 204b. Additionally or alternatively, the controllers 240a, 240b can control the opening of the bleed port valves 244a, 244b to vent the gas in the capillary constrictions 250a, 250b. In this way, the gas in the capillary constrictions 250a, 250b can be vented in both the downstream direction and the upstream direction to further accelerate the gas venting of the capillary constrictions 250a, 250b without having to vent the gas in the gas supply lines 204a, 204b, as will be discussed further below. The controllers 240a, 240b can also control the bleed port valves 244a, 244b to vent the gas from both the supply lines 204a, 204b and the capillary constrictions 250a, 250b simultaneously to accelerate the venting of all the gas from the plasma source system 280.

[0030] Because the controllers 240a, 240b are fluidly coupled to the capillary constrictions 250a, 250b to individually control the flow rate of each gas species entering the gas mixture, the partial pressure of each gas from the gas reservoirs 230a, 230b can be more precisely controlled. Additionally, the capillary constrictions 250a, 250b can be different from each other to facilitate this increased precision by ensuring that each gas is delivered directly into the bypass chamber 254 at a specific pressure without being altered by the introduction of other gases. The capillary constrictions 250a, 250b can be different from each other, wherein the gas in each of the capillary constrictions 250a, 250b does not interact with other gases until they are mixed in the plasma source chamber 202. For example, the capillary constrictions 250a, 250b can be spaced apart from each other. The capillary constrictions 250a, 250b can also not intersect with each other. The capillary constrictions 250a, 250b can also be separated from each other. In this way, the controllers 240a, 240b can be individually adjusted to allow each gas to enter the bypass manifold 252 at a specific gas flow rate, thereby allowing for more precise control of the pressure of each gas in the total pressure of the gas mixture.

[0031] In addition, since each of the capillary constriction portions 250a, 250b is different from each other, each of the controllers 240a, 240b can sense the pressure for each gas species in the corresponding gas supply lines 204a, 204b, and the pressure of other gas species will not potentially interfere with the pressure sensors in each of the controllers 240a, 240b. In this way, the controllers 240a, 240b can more accurately sense the pressure of each gas species in the gas supply lines 204a, 204b. Subsequently, these more accurate pressure measurements can allow the controllers 240a, 240b to more accurately and precisely control the flow rate of the gas entering the capillary constriction portions 250a, 250b. Compared with other embodiments where the pressure of other gases may interfere with the pressure sensing of the controller (for example, if the controllers are positioned along the same gas supply line, similar to Figure 1 the valves 131a, 131b, 131c, 131d shown), this may be particularly beneficial. In such embodiments, the pressure of each gas in the gas from the supply line will be mixed together, such that the controller will not be able to sense the partial pressure of each gas species. Such an embodiment will not be able to accurately control the partial pressure of each gas species in the gas mixture and thus cannot precisely control the composition of the gas mixture. This problem may be complex in embodiments using constriction portions because the volume of the gas supply line between the controller and the constriction portion may increase the difficulty of controlling the composition of the gas mixture, since the actual pressure of each gas downstream of this volume may not likely represent the sensed pressure of each gas upstream of this volume (e.g., where the controller is positioned).

[0032] On the other hand, the controllers 240a, 240b directly connected to the corresponding capillary constriction portions 250a, 250b before the gases are mixed in the plasma source chamber 202 can more precisely control the composition of the gas mixture. By making small adjustments to the composition of the gas mixture specific to each layer of sample material, this may be beneficial for optimizing the grinding and polishing operations. This can also allow the grinding process for a specific material to be accelerated or decelerated as needed. In addition, such dynamic adjustment of the gas mixture can minimize the gas shielding effect by controlling the volatilization and re - deposition of the sputtered material.

[0033] The controllers 240a, 240b can release gas separately and independently of each other. For example, even when the gas supply lines 204a, 204b include the same pressure, the first controller 240a can release gas from the first gas supply line 204a downstream to the first capillary constriction portion 250a at a first flow rate different from the second flow rate at which the second controller 240b releases gas from the second gas supply line 204b to the second capillary constriction portion 250b. In this way, the gases from the gas reservoirs 230a, 230b can be released into the bypass chamber 254 simultaneously or cyclically.

[0034] The controllers 240a, 240b can simultaneously release gas by releasing gas into the corresponding capillary constrictions 250a, 250b at a flow rate greater than zero. This can include releasing gas from each of the gas supply lines 204a, 204b into the capillary constrictions 250a, 250b at the same flow rate or at different flow rates. The controllers 240a, 240b can release gas at a constant flow rate such that the components of the gas mixture remain constant over a period of time (e.g., when milling through a layer of sample material). The controllers 240a, 240b can additionally or alternatively release gas at a variable rate such that the components of the gas mixture change over a period of time (e.g., when milling through a transition in the sample material).

[0035] The controllers 240a, 240b can cyclically release gas by setting the first flow rate of the first gas to zero (e.g., stopping the downstream flow of gas) and the second flow rate of the second gas to non-zero during a first time period. After the first time period, the controllers 240a, 240b can then set the first flow rate to non-zero and can set the second flow rate to zero during a second time period. The controllers 240a, 240b can thus cyclically release gas by cycling at least one downstream gas flow rate to zero in this manner. In some embodiments, in the presence of more than two gas reservoirs, the controller can release some of the gases one after the other while also cycling out other gases. For example, the controller can release two or more gases at similar or different non-zero flow rates while setting one or more of the other gases to a zero flow rate for a period of time and cycling at least one gas to have a zero flow rate in each period.

[0036] Controllers 240a, 240b and capillary constrictions 250a, 250b are fluidly connectable, and at least one of controllers 240a, 240b and capillary constrictions 250a, 250b is directly connected to chamber body 260. Chamber body 260 may define an opening adjacent to controllers 240a, 240b such that capillary constrictions 250a, 250b are fluidly connectable to controllers 240a, 240b without being directly connected to each other. For example, a portion of controllers 240a, 240b may extend through chamber body 260 to fluidly connect capillary constrictions 250a, 250b to controllers 240a, 240b. As another example, capillary constrictions 250a, 250b may extend through chamber body 260 to fluidly connect capillary constrictions 250a, 250b to controllers 240a, 240b. In yet another different example, capillary constrictions 250a, 250b and controllers 240a, 240b may be connected to opposite sides of chamber body 260 but may be fluidly connected to each other through an opening in chamber body 260.

[0037] Controllers 240a, 240b may release gas from gas supply lines 204a, 204b at any flow rate between a maximum flow rate at which gas is released into capillary constrictions 250a, 250b at a pressure equal to the pressure in gas supply lines 204a, 204b and a minimum flow rate at which no gas is released into capillary constrictions 250a, 250b. In this way, controllers 240a, 240b may act as a stop in the gas flow path between gas supply lines 204a, 204b and capillary constrictions 250a, 250b such that the gas in gas supply lines 204a, 204b is fluidly isolated from capillary constrictions 250a, 250b. This allows the pressure in gas supply lines 204a, 204b to remain at a constant pressure and the pressure in capillary constrictions 250a, 250b to be variable. As will be described further below, this can be beneficial when evacuating a gas mixture because only the gas in capillary constrictions 250a, 250b will need to be evacuated rather than the entire gas supply lines 204a, 204b (as in Figure 1 gas supply line 104 in).

[0038] The capillary constriction portions 250a, 250b may each be tubes having respective first ends 251a, 251b coupled to the chamber body 260 and respective second ends 253a, 253b coupled to the bypass manifold 252. The diameters of the capillary constriction portions 250a, 250b may be dimensioned to improve their high voltage tolerance and thus minimize any plasma peristalsis within the capillary constriction portions 250a, 250b and minimize arc discharges. For example, the diameters may be dimensioned to reduce the mean free path length of the gas in the plasma cell. Due to the high electric field potential in the plasma region, this can help prevent high voltage breakdown by gradually reducing the pressure across the capillary constriction to a level that withstands Paschen breakdown. The capillary constriction portions 250a, 250b may be made of an electrically insulating material (e.g., plastic, rubber, etc.) to further prevent arc discharges. The inner surfaces of the capillary constriction portions 250a, 250b defining the inner diameter may further include a fused silica lining to resist carbonization due to arc discharges and resist gas permeation. The length may be dimensioned to provide sufficient flow rate to withstand the plasma cell pressure and allow for adjustability of the gas mixture.

[0039] For example, the capillary contraction 250a, 250b may have a diameter of about 100 μm, such as less than about 75 μm, less than about 50 μm, or less than about 25 μm. Since the diameter can be more consistent than the contraction defined in the tube of other plasma source systems, the gas delivery through the capillary contraction 250a, 250b can be more consistent and repeatable. The capillary contraction 250a, 250b may have a length between about 50 mm and 280 mm, such as between about 75 mm and 175 mm, or such as between about 100 mm and 150 mm. This length may allow components sensitive to plasma arc discharge (e.g., controllers 240a, 240b, grounded housings or other structural components) to be positioned sufficiently away from areas of high field potential to prevent arc discharge by approaching. In a preferred embodiment, the capillary contraction 250a, 250b may have a preferred diameter of about 50 μm and a length of about 150 mm. The capillary contractions 250a, 250b may have similar dimensions, however, in other embodiments, each of the capillary contractions may have different dimensions. In another alternative, where there are three or more capillary contractions, only some of the capillary contractions may have similar dimensions (e.g., two of the three capillary contractions have similar dimensions, etc.). These dimensions may minimize the pressure drop across the capillary contractions 250a, 250b (e.g., approximately 100 to 1000 millibars) compared to the larger pressure drop (e.g., approximately 2 to 3 bar) when the contraction is used in other plasma source systems, thereby allowing the pressure and flow rate of the gas entering the capillary contractions 250a, 250b to be more easily controlled than the gas entering the contraction in those other systems.

[0040] As will be discussed further below, the small size of the capillary contractions 250a, 250b, and thus the small volume of gas that each capillary contraction 250 can contain, can reduce gas waste when evacuating gas from the plasma source system 280. In addition, the capillary contractions 250a, 250b can be more compact than other components used to deliver gas, such as Figure 1 The tube 108 in FIG. 1 is cheaper because the capillary constrictions 250 a, 250 b can have a less complex geometry (e.g., not including a change in diameter along its length, such as Figure 1 The contraction 110 in the capillary tube may be of a uniform diameter and any type of material may be used, including glass (e.g., silicon dioxide), metal, etc.

[0041] The chamber body 260 can be in fluid communication with a vacuum source (e.g., a vacuum pump 270) such that the internal volume 262 is under vacuum. However, in other embodiments, the internal volume 262 may not be in fluid communication with the vacuum source, and instead, the vacuum source may be in fluid communication with other components of the charged particle system (such as a bypass chamber and / or a controller). Thus, as discussed further below, gas can be evacuated through the bypass chamber and / or the controller. The bypass manifold 252 can be a structure that defines a bypass chamber 254 such that when the bypass manifold 252 and the plasma source tube 203 are coupled together, as Figure 2A shown, the bypass manifold 252 can fluidly isolate the capillary constrictions 250a, 250b, the bypass chamber 254, and the plasma source chamber 202 from the internal volume 262. Thus, the gas in the capillary constrictions 250a, 250b, the bypass chamber 254, and the plasma source chamber 202 can be used to generate plasma 255 without escaping into the internal volume 262. In some embodiments, a controller can be fluidly coupled between the bypass chamber and the plasma source chamber. This is beneficial for controlling the gas flow into the plasma source until desired. For example, this controller can stop the gas from entering the plasma source until all the gas is well mixed in the bypass chamber to form a homogenized gas mixture. Once the gas mixture is formed, the controller can release the gas mixture from the bypass chamber into the plasma source chamber.

[0042] As described above, when switching the gas species used in the gas mixture, other plasma source systems typically require the gas in the entire system to be completely evacuated (e.g., the pump 122 evacuates the gas from all items in the plasma source chamber 102, the tube 108, and the gas supply line 104 in Figure 1 . This is costly because wasting such gas is expensive. Additionally, evacuating the entire system takes an unnecessarily long time. The plasma source system of the present disclosure addresses these problems by allowing the gas species to be changed by partially evacuating the system, resulting in considerably less gas waste.

[0043] The gas from the plasma source system 280 can be partially evacuated by evacuating only the gas in the plasma source chamber 202, the bypass chamber 254, and the capillary constrictions 250a, 250b. Specifically, the bypass actuator 242 can be instructed to move the bypass manifold 252 from Figure 2A the first state shown to Figure 2BThe second state shown. This allows the gas in the capillary constriction portions 250a, 250b, the bypass chamber 254, and the plasma source chamber 202 to escape into the internal volume 262 along the arrow A. Then, the gas can be evacuated from the charged particle system 200 by flowing to a vacuum source. It should be understood that the distance that the bypass manifold 252 moves from the first state to the second state is for illustrative purposes only, and the bypass manifold 252 can move any distance between the states to allow gas evacuation. In other embodiments where the bypass chamber and / or the controller are in fluid communication with the vacuum source rather than with the internal volume, the gas can be evacuated to the vacuum source through the bypass chamber and / or the controller.

[0044] Since the gas from the gas supply lines 204a, 204b does not need to be evacuated during this gas species change, the gas in the gas supply lines 204a, 204b is not wasted unnecessarily. In addition, this partial evacuation saves time because it is not necessary to evacuate the gas supply lines 204a, 204b to change the gas species. Further still, since the capillary constriction portions 250a, 250b can be much smaller (e.g., between about 50,000 times to 200,000 times smaller) than the gas supply lines used in other plasma source systems (e.g., the gas supply line 104 in Figure 1 ), less gas needs to be evacuated, thus saving even more time and further minimizing gas waste.

[0045] Additionally, changing the gas species can be faster overall, as shown in examples where there are more than two gas reservoirs and one or more gas species are swapped out. In this example, the gas valves can release three or more gas reservoirs to pressurize their respective gas supply lines. However, only the first controller releases the first gas species from the first gas reservoir into the first capillary constriction, and the second controller releases the second gas species from the second gas reservoir into the second capillary constriction to form a first gas mixture. Later in the process, it may be desirable to change the first gas species to a third gas species that has not been introduced into the plasma source chamber but has been released into the corresponding gas supply line. As described above, the first gas species and the second gas species can be evacuated from their respective capillary constrictions without evacuating the gas supply lines of all the gas reservoirs. Then, the second controller can release the second gas species back into the second capillary constriction, while the third controller can release the third gas species into the third capillary constriction to form a second gas mixture without the first gas species. This process highlights a further benefit of the capillary constrictions and the controllers, because not only is the evacuation of the first gas species and the second gas species faster and less wasteful as discussed above, but the introduction of the third gas species is also faster. Specifically, since the third gas supply line corresponding to the third gas reservoir has already been pressurized and is ready to be introduced into the third capillary constriction (and thus into the bypass chamber and the plasma source chamber), it takes less time to form this second gas mixture compared to other plasma source systems that require the entire gas supply to be evacuated and repressurized when changing the gas species.

[0046] By utilizing the bleed port valves 244a, 244b defined in the controllers 240a, 240b, the gases in the capillary constrictions 250a, 250b can be evacuated more conveniently without wasting the gases in the gas supply lines 204a, 204b. Specifically, the controllers 240a, 240b can control the bleed port valves 244a, 244b to evacuate the gases in the capillary constrictions 250a, 250b from the first ends 251a, 251b, while the gases are evacuated from the second ends 253a, 253b through the bypass chamber 254 into the internal volume 262. Since the controllers 240a, 240b can control the bleed port valves 244a, 244b to allow the evacuation of the gases in the capillary constrictions 250a, 250b without affecting the gases in the gas supply lines 204a, 204b, the gases in the gas supply lines 204a, 204b are not wasted by using the bleed port valves 244a, 244b to evacuate the gases in the capillary constrictions 250a, 250b.

[0047] When the entire plasma source system 280 is being evacuated (e.g., all gas supply lines 204a, 204b, capillary constrictions 250a, 250b, bypass chamber 254, and plasma source chamber 202), the charged particle system 200 can evacuate gas faster than other plasma source systems. Using the bleed port valves 244a, 244b, the gas in the gas supply lines 204a, 204b can be evacuated from both ends: evacuated from one end by pumps 222a, 222b, and evacuated from the other end by the corresponding bleed port valves 244a, 244b in the controllers 240a, 240b. In this way, compared with other plasma source systems that only use pumps (e.g., the pump 122 in Figure 1 to evacuate the gas supply line), the gas supply lines 204a, 204b can be evacuated more conveniently. In some embodiments, the gas in the gas supply line can be evacuated without evacuating the gas in the capillary constrictions, bypass chamber, and plasma source chamber.

[0048] Figure 3 FIG. 300 depicts a diagram showing the gas flow path of the plasma source system. It should be understood that features ended with reference numerals similar to those discussed above are similar, unless otherwise indicated below. As shown, the plasma source can have any number of gas reservoirs 330a, 330b, 330c, 330...n. The following description will focus on the gas flow path of the first gas from the first gas reservoir 330a. However, it should be understood that the gas flow paths of other gases from other gas reservoirs 330b, 330c, 330...n can follow corresponding similar paths as Figure 3 shown.

[0049] When introducing gas into the plasma source chamber 302, the first gas from the first gas reservoir 330a can be released (e.g., via a gas valve, such as Figure 2A and Figure 2B the valve 231a in to enter the corresponding gas supply line (e.g., gas supply line 204a). The first gas can flow along the gas supply line along the first flow path A1 to both the first controller 340a and the first pump 322a. At this time, the first pump 322a may not be started, and thus may not release the first gas to the vacuum source. The first controller 340a can be opened to release the first gas to the capillary constriction 350a and then to the bypass chamber 354 via the second gas flow path B1. This first gas can then flow from the bypass chamber 354 into the plasma source chamber 302 along the third gas flow path C to mix with one or more other gases (if any) from other gas reservoirs 330b, 330c, 330...n to form a gas mixture. Then this gas mixture can be used to generate plasma and ion beam extraction.

[0050] When only evacuating the gases in the capillary constriction 350a, the bypass chamber 354, and the plasma source chamber 302, the bypass actuator (e.g., the bypass actuator 242) can be instructed to move the bypass manifold (e.g., the bypass manifold 252) away from the plasma source tube (e.g., the plasma source tube 203), so that the gases in the capillary constriction 350a, the bypass chamber 354, and the plasma source chamber 302 flow into the internal volume 362 along the fourth flow path D. Then, these gases can flow along the fifth flow path E to the vacuum source. When the controller 340a opens the bleed port valve (e.g., Figure 2A and Figure 2B the bleed port valve 244a in), these gases can also be evacuated from the other end of the capillary constriction 350a to evacuate the gases through the capillary constriction 350a along the sixth flow path F1. When evacuating the gases from the gas supply line, the pump 322a can evacuate one end of the gas supply line, so that the gases flow from the gas supply line to the vacuum source along H1. The controller 340a can open the bleed port valve to evacuate the gases from the other end of the gas supply line, so that the gases flow to the vacuum source along the gas supply line along G1.

[0051] Figure 4 、 Figure 5 、 Figure 6 and Figure 7 illustrate example flowcharts showing the corresponding processes 400, 500, 600, and 700 as described herein. The processes 400, 500, 600, and 700 are illustrated as logic flowcharts, and each operation of the logic flowchart represents a sequence of operations that can be implemented in hardware, computer instructions, or a combination thereof. For example, the operations can be computer instructions provided by a computer system (such as Figure 2A and Figure 2B the computer system 290 in and Figure 8 the computer system 810 in). In the context of computer instructions, the operations represent computer-executable instructions stored on one or more computer-readable storage media, and the computer-executable instructions, when executed by one or more processors, perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, etc. that perform specific functions or implement specific data types. The order of describing the operations is not intended to be construed as a limitation, and any number of the described operations can be omitted or combined in any order and / or in parallel to implement the process.

[0052] Additionally, some, any, or all of these processes can be performed under the control of one or more computer systems configured with executable instructions and can be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) executed jointly on one or more processors, by hardware, or a combination thereof. As described above, the code can be stored, for example, in the form of a computer program including multiple instructions executable by one or more processors, on a computer-readable storage medium. The computer-readable storage medium is non-transitory.

[0053] Figure 4 FIG. depicts an example flowchart of a process 400 for using a plasma source to adjust the ratio of gas species in a gas mixture. It should be understood that features ending with reference numerals similar to those discussed above are similar, unless otherwise indicated below. As discussed above, any of the steps in the process can be instructions provided by a computer system. Such adjustment can be performed in real time or before plasma generation. Turning to step 410, a desired ion ratio can be provided to a computer system (e.g., computer system 290). For example, a user may desire an ion ratio of 70% oxygen and 30% xenon to grind a particular portion of a sample. Turning to step 420, the computer system can predict the gas mixture components for providing the desired ion ratio. For example, the computer system can predict that a gas mixture of 80% oxygen and 20% xenon can be used to achieve the desired ion ratio. Note that due to various factors, including physical and chemical effects in the chamber (e.g., RF power, temperature in the system, ionization efficiency of each gas, total pressure in the plasma chamber, generation of both atomic and molecular species such as O+ and O2+, or chemical interactions between gases or between gases and system components), the selected gas mixing ratio may not translate to the same ion mixing ratio. In some examples, different systems may give slightly different ion mixing ratios from the same gas mixture input.

[0054] This prediction can be based on a prediction model trained using machine learning techniques such as Hidden Markov models, convolutional neural networks, polynomial regression, and cluster analysis. Training the prediction model can include using a variety of different optimization techniques to optimize a loss function such that the address risk model outputs closely tracks the actual counterfeiting behavior of the training set. Such optimization techniques can include gradient descent, backpropagation, conjugate gradient, other gradient techniques, or hessian techniques such as Newton's method. The loss function can be the difference between the measured ion ratio and the predicted ion ratio at one or more time points. The prediction model can be a machine learning model trained using a large dataset including input parameters (e.g., gas mixture components, RF power, total pressure of the gas mixture, etc.) and the resulting ion ratios. Thus, the prediction model can find patterns between the gas mixture and the ion ratio such that the prediction model can output the gas mixture components predicted to produce a desired ion ratio. Alternatively, the prediction model can output the predicted ion ratio that can be produced by a certain gas mixture. In other embodiments, the prediction can be based on an estimation table pre-populated with estimated gas mixtures that will produce estimated ion gas ratios. In some embodiments, the estimation table is specific to a particular system because each system can produce different ion ratio outputs due to subtle differences in plasma generation based on each hardware implementation.

[0055] The plasma source system can generate the predicted gas mixture. For example, referring to Figure 2A , the controllers 240a, 240b can introduce at least one gas species from each of the gas reservoirs 230a, 230b into the corresponding capillary constrictions 250a, 250b such that each gas species can have a partial pressure within the plasma source chamber 202 to form the predicted gas mixture. Returning to Figure 4 , at step 430, this predicted gas mixture can be introduced into the plasma source chamber 202 in the plasma source tube 203. Moving to step 440, the gas mixture can be ionized to extract an ion beam from the gas mixture. Moving to step 450, it can be measured by a measuring unit (e.g., Figure 2A and Figure 2BThe measurement unit 275) in measures the ion ratio. Further details regarding the measurement of this ion ratio can be found in U.S.P.N. 10,763,079, the content of which is hereby incorporated by reference in its entirety. The ion ratio can be measured continuously (e.g., once every millisecond, 1 second, 5 seconds, 10 seconds, 1 minute, etc.) to provide data regarding the measured ion ratio while the ion beam mills the sample. In this way, data regarding the measured ion ratio can be continuously provided to the computer system as the ion beam mills through the respective sample layers and when the ion beam is adjusted to adjust the ion ratio. However, in other embodiments, the ion ratio can be measured only when instructed, such as when the user actively instructs the computer system to measure the ion ratio.

[0056] Moving to step 460, the computer system can determine whether the ion ratio is correct. Specifically, the computer system can compare whether the measured ion ratio is substantially similar to the desired ion ratio input in step 410. The ion ratio can be substantially similar when the measured ion ratio value is within about 20% deviation of the desired ion ratio value (such as about 10% deviation, such as about 5% deviation) or is exactly the same. If the ion ratio is substantially similar, the process can continue in step 470 (e.g., continue extracting the ion beam to mill the sample).

[0057] If the measured ion ratio is not substantially similar, one or more input parameters can be adjusted in step 480 to achieve the desired ion ratio. For example, one or more gas species in the gas mixture can be adjusted to adjust the ion ratio. This can include adjusting the partial pressure of a particular gas species in the gas mixture, as described above, to change the composition of the gas mixture. In some embodiments, all gas species can be swapped out with another gas species (or completely removed from the gas mixture). The RF power can also be adjusted to change the ion ratio of the ion beam. The total pressure of the gas mixture in the plasma source chamber can be adjusted to affect the change in the ion ratio. In some embodiments, only one of these parameters can be adjusted, however, in other embodiments, multiple parameters (e.g., all parameters) can be adjusted. Once the parameters are adjusted, the ion beam can be extracted and the ion ratio measured again. The computer system can compare whether the new ion ratio is substantially similar to the desired ion ratio. The computer can repeat the above process as needed until the measured ion ratio is substantially similar to the desired ion ratio.

[0058] In either case, the measured ion ratio can be provided to the prediction model as additional data for updating the prediction model. For example, if the measured ion ratio is substantially similar to the desired ion ratio, the data regarding the measured ion ratio can confirm the accuracy of the prediction model for these particular gas species (e.g., confirm that the parameters predicted by the prediction model provide an ion ratio that is substantially similar to the desired ion ratio). This can result in minimal or no change to the prediction model. If the measured ion ratio is not substantially similar to the desired ion ratio, the data regarding the measured ion ratio can indicate that the prediction model for these particular gas species is inaccurate. This can result in a change to the prediction model to account for this data such that future prediction models can provide a measured ion ratio that more accurately corresponds to the desired ion ratio (e.g., change the parameters predicted by the prediction model to provide the desired ion ratio). The prediction model can be updated in real-time (e.g., when data is provided to the prediction model) or can be updated at a later date (e.g., once enough data has been collected before a new version of the prediction model is provided to the computer system).

[0059] In some examples, changes to the prediction model can be used to perform system health monitoring. The computer system can maintain a history of updates to the prediction model (e.g., in a storage device or memory). When the system is in a steady state (i.e., healthy), the frequency of updates to the prediction model can be low because the measured ion ratio is typically substantially similar to the desired ion ratio. However, when one or more components of the system begin to degrade, the updates to the prediction model become more frequent and / or the deviation between the measured ion ratio and the desired ion ratio can become larger. In some examples, the computer can analyze the history of updates to the prediction model to determine that the system may need maintenance. Upon determining that the system needs maintenance, the computer can notify the user to schedule service or use a message on a graphical user interface such as a monitor to check for degradation of the components of the system, as described below with respect to Figure 8 as described.

[0060] Figure 5 FIG. 500 depicts an example flow diagram showing a process 500 for mixing gases in a plasma source chamber. It should be understood that features with reference numerals ending in a reference numeral similar to those discussed above are similar, unless otherwise indicated below. For example, Figure 5 the flow diagram in Figure 4 can provide a more detailed process for step 430 in the flow diagram shown in Figure 2AA plasma source system 280 as shown is described. As discussed above, any of the steps in the process can be instructions provided by a computer system. Moving to step 510, valves 231a, 231b can be opened to release gas from gas reservoirs 230a, 230b into gas supply lines 204a, 204b until a desired pressure (e.g., about 100 mbar to 1000 mbar) is reached. Moving to step 520, controllers 240a, 240b can be opened to release each of the gases in a controlled rate or volume from gas supply lines 204a, 204b into capillary constrictions 250a, 250b. Each of controllers 240a, 240b can release gas from gas supply lines 204a, 204b into capillary constrictions 250a, 250b to achieve a desired gas mixture and ion ratio in plasma source chamber 202. Specifically, each of controllers 240a, 240b can release each gas species in the gas species at an individualized pressure such that each gas species in the gas species will have a partial pressure within the gas mixture and thus achieve a specific gas mixture composition. As described above, this gas mixture in plasma source chamber 202 will then be ionized to extract an ion beam for abrading a sample.

[0061] Figure 6 An example flowchart depicting a process 600 for evacuating gas from a plasma source is shown. It should be understood that features ending with reference numerals similar to those discussed above are similar unless otherwise indicated below. Figure 6 The flowchart in will be referenced Figure 2BThe plasma source system 280 shown is described. As discussed above, any of the steps in the process can be instructions provided by a computer system. Turning to step 610, to partially evacuate the plasma source system 280, the bypass manifold 252 can be disengaged from the plasma source tube 203. Specifically, the bypass actuator 242 can be actuated to move the bypass manifold 252 away from the plasma source tube 203. Disengaging the bypass manifold 252 from the plasma source tube 203 will allow the gas in the capillary constrictions 250a, 250b, the bypass chamber 254, and the plasma source chamber 202 to be evacuated into the internal volume 262, which will in turn flow towards the vacuum source. This will partially evacuate the plasma source system 280 such that when the controllers 240a, 240b fluidly isolate the gas supply lines 204a, 204b from the capillary constrictions 250a, 250b, the gas in the capillary constrictions 250a, 250b, the bypass chamber 254, and the plasma source chamber 202 can be evacuated without evacuating the gas in the gas supply lines 204a, 204b. In some embodiments, turning to step 620, the controllers 240a, 240b can open the bleed port valves 244a, 244b to allow the gas to be evacuated from the capillary constrictions 250a, 250b at the first ends 251a, 251b to more rapidly evacuate the gas from the capillary constrictions 250a, 250b, the bypass chamber 254, and the plasma source chamber 202. The plasma source system 280 can be fully evacuated by also opening the pumps 222a, 222b to release the gas in the gas supply lines 204a, 204b at the first ends and / or opening the bleed port valves 244a, 244b of the controllers 240a, 240b to release the gas in the gas supply lines 204a, 204b at the second ends.

[0062] Figure 7 The example flowchart of process 500 is depicted that shows the process for a computer system to provide instructions to a plasma source for a mixed gas. It should be understood that features ending with reference numerals similar to those discussed above are similar, unless otherwise indicated below. Figure 7 The flowchart in will be referenced Figure 2AA description is given of the charged particle system 200 shown. Turning to step 710, the computer system 290 may instruct the first controller 240a to open the first variable outlet pressure valve to release the first gas from the first gas reservoir 230a at a first flow rate via the first capillary constriction 250a into the plasma source chamber 202. Turning to step 720, the computer system 290 may instruct the second controller 240b to open the second variable outlet pressure valve to release the second gas at a second flow rate from the second gas reservoir 230b via the second capillary constriction 250b into the plasma source chamber 202. The second capillary constriction 250b may be different from the first capillary constriction 250a. As described above, the gas may flow from the capillary constrictions 250a, 250b into the bypass chamber 254 and then into the plasma source chamber 202 before being ionized. Thus, the computer system 290 may facilitate precise control of the partial pressure of each gas species from the gas reservoirs 230a, 230b to achieve a specific composition of the gas mixture.

[0063] To partially evacuate the charged particle system 200, the computer system 290 may also instruct the bypass actuator 242 to move the bypass manifold 252 away from the source tube 203 such that the first capillary constriction 250a and the second capillary constriction 250b, the bypass chamber 254, and the plasma source chamber 202 are in fluid communication with a vacuum source. The computer system 290 may also open a first bleed port valve 244a defined in the first controller 240a to fluidly couple the first capillary constriction 250a to the vacuum source and open a second bleed port valve 244b defined in the second controller 240b to fluidly couple the second capillary constriction 250b to the vacuum source.

[0064] Any of the computer systems mentioned herein may utilize any suitable number of subsystems. Examples of such subsystems are shown in Figure 8 in the computer system 810. In some embodiments, the computer system comprises a single computer device, where the subsystems may be components of the computer device. In other embodiments, the computer system may comprise multiple computer devices, each computer device being a subsystem with internal components. The computer system may include desktop computers and laptop computers, tablet computers, mobile phones, and other mobile devices.

[0065] Figure 8 The subsystems shown are interconnected via a system bus 875. Peripherals and input / output (I / O) devices such as a printer 874, a keyboard 878, a storage device 879, a monitor 876 (e.g., a display screen such as an LED) coupled to a display adapter 882, etc. are shown. Peripheral devices and input / output (I / O) devices coupled to the I / O controller 871 may be connected through, for example, input / output (I / O) ports 877 (e.g., USB, Any number of means known in the art, such as the like, are connected to the computer system. For example, the I / O port 877 or the external interface 881 (e.g., Ethernet, Wi-Fi, etc.) can be used to connect the computer system 810 to a wide area network such as the Internet, a mouse input device, or a scanner. The interconnection via the system bus 875 allows the central processing unit 873 to communicate with each subsystem and control the execution of multiple instructions from the system memory 872 or the storage device 879 (e.g., a fixed hard disk such as a hard disk drive or an optical disk), as well as the exchange of information between subsystems. The system memory 872 and / or the storage device 879 can be embodied as a computer-readable medium. Another subsystem is the data collection device 885, such as a camera, a microphone, an accelerometer, etc. Any data mentioned herein can be output from one component to another component and can be output to the user.

[0066] The computer system can include multiple identical components or subsystems, for example, connected together via the external interface 881, via an internal interface, or via a removable storage device that can be connected to and removed from one component to another. In some embodiments, the computer system, subsystem, or device can communicate via a network. In such instances, one computer can be considered a client, and another computer can be considered a server, where the client and the server can each be part of the same computer system. The client and the server can each include multiple systems, subsystems, or components.

[0067] Aspects of the embodiments can be implemented using hardware circuits (e.g., application-specific integrated circuits or field-programmable gate arrays) and / or in a modular or integrated manner using computer software stored in a memory with a general programmable processor in the form of control logic, and thus the processor can include a memory storing software instructions for configuring the hardware circuit and an FPGA or ASIC with configuration instructions. As used herein, the processor can include a single-core processor, a multi-core processor on the same integrated chip, or multiple processing units on a single circuit board or networked, as well as dedicated hardware. Based on the disclosure and teachings provided herein, those of ordinary skill in the art will know and appreciate other ways and / or methods of implementing the embodiments of the present disclosure using hardware and combinations of hardware and software.

[0068] Any of the software components or functions described in this application (such as processes 400, 500, 600, or 700) can be implemented as software code to be executed by a processor using any suitable computer language (such as, for example, Java, C, C++, C#, Objective-C, Swift) or scripting language (such as Perl or Python using, for example, conventional or object-oriented techniques). The software code can be stored on a computer-readable medium as a series of instructions or commands for storage and / or transmission. Suitable non-transitory computer-readable media can include random access memory (RAM), read-only memory (ROM), magnetic media (such as a hard disk drive or a floppy disk), or optical media (such as a compact disc (CD) or a digital versatile disc (DVD) or a Blu-ray disc), flash memory, etc. The computer-readable media can be any combination of such devices. Additionally, the order of operations can be rearranged. The process can terminate when its operations are complete, but can have additional steps not included in the figures. The process can correspond to a method, function, procedure, subroutine, subprogram, etc. When the process corresponds to a function, its termination can correspond to the function returning to the calling function or the main function

[0069] Such programs can also be encoded and transmitted using a carrier signal suitable for transmission via wired, optical, and / or wireless networks (including the Internet) that comply with various protocols. In this way, a computer-readable medium can be created using the data signal encoded with such a program. The computer-readable medium encoded with the program code can be packaged with a compatible device or provided separately from other devices (for example, downloaded via the Internet). Any such computer-readable medium can reside on a single computer product (such as a hard disk drive, a CD, or an entire computer system) or within a single computer product, and can be present on different computer products or within different computer products in a system or network. The computer system can include a monitor, a printer, or other suitable display for providing any of the results mentioned herein to a user.

[0070] Any of the methods described herein may be performed, in whole or in part, by a computer system including one or more processors that may be configured to perform the steps. Any operations performed by the processor (e.g., aligning, determining, comparing, calculating, measuring) may be performed in real time. The term "real time" may refer to a computational operation or process that is completed within a specific time constraint. The time constraint may be 1 minute, 1 hour, 1 day, or 7 days. Accordingly, embodiments may relate to a computer system configured to perform the steps of any of the methods described herein, potentially having different components for performing the corresponding steps or groups of corresponding steps. Although presented as numbered steps, the steps of the methods herein may be performed simultaneously or at different times or in a different order. Additionally, portions of these steps may be used in conjunction with portions of other steps from other methods. Additionally, all or part of the steps may be optional. Additionally, any of the steps of any of the methods herein may be performed by a module, unit, circuit, or other means of a system for performing those steps.

[0071] In the foregoing specification, embodiments of the present disclosure have been described with reference to numerous specific details, which may vary according to the embodiments. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive. The sole and exclusive indication of the scope of the present disclosure, and what the applicant intends to be the scope of the present disclosure, is the literal and equivalent scope of this set of claims as issued in the specific form from this application, including any subsequent amendments. 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.

[0072] Additionally, spatial relative terms such as "bottom" or "top" may be used to describe the relationship of an element and / or feature to another element and / or feature, as illustrated, for example, in the figures. It should be understood that spatial relative terms are intended to encompass different orientations of the device in use and / or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as the "bottom" surface may be oriented "above" other elements or features. The device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial descriptors used herein may be interpreted accordingly.

[0073] As used herein, the terms "and", "or", and "and / or" can include a variety of meanings, which are also expected to depend at least in part on the context in which such terms are used. Generally, if used in an associative list such as A, B, or C, "or" is intended to mean A, B, and C (used here in an inclusive sense), as well as A, B, or C (used here in an exclusive sense). In addition, as used herein, the term "one or more" can be used to describe any feature, structure, or property in the singular form, or can be used to describe a certain combination of features, structures, or properties. However, it should be noted that this is only an illustrative example, and the claimed subject matter is not limited to this example. In addition, if used in an associative list such as A, B, or C, the term "at least one of" can be interpreted to mean any combination of A, B, and / or C, such as A, B, C, AB, AC, BC, AA, AAB, ABC, AABBCCC, etc.

[0074] References throughout this specification to "an example", "example", "certain examples", or "exemplary embodiments" mean that a particular feature, structure, or property described in connection with that feature and / or example can be included in at least one feature and / or example of the claimed subject matter. Thus, the appearances of the phrases "in one example", "example", "in certain examples", "in certain embodiments", or other similar phrases throughout this specification are not necessarily all referring to the same feature, example, and / or limitation. In addition, particular features, structures, or properties can be combined in one or more examples and / or features.

[0075] In some embodiments, an operation or process can involve the physical manipulation of physical quantities. Generally but not necessarily, such quantities can take the form of electrical or magnetic signals that can be stored, transferred, combined, compared, or otherwise manipulated. For primarily reasons of common usage, it has proven convenient at times to refer to such signals as bits, data, values, elements, symbols, characters, items, quantities, numbers, etc. However, it should be understood that all of these or similar terms will be associated with appropriate physical quantities and are merely convenient labels. Unless otherwise specifically stated, as will be apparent from the discussion herein, it should be understood that throughout this specification, discussions using terms such as "processing", "computing", "estimating", "determining", etc. refer to the actions or processes of a particular apparatus (such as a special-purpose computer, a special-purpose computing device, or a similar special-purpose electronic computing device). Thus, in the context of this specification, a special-purpose computer or a similar special-purpose electronic computing device can manipulate or transform signals that are typically represented as physical electrical or magnetic quantities within the memory, registers, or other information storage devices, transmission devices, or display devices of the special-purpose computer or similar special-purpose electronic computing device.

[0076] In the foregoing detailed description, numerous specific details have been set forth in order to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter may be practiced without these specific details. In other instances, methods and devices that are well known to one of ordinary skill in the art have not been described in detail so as not to obscure the claimed subject matter. Accordingly, it is intended that the claimed subject matter not be limited to the specific examples disclosed, but that the claimed subject matter also include all aspects falling within the scope of the appended claims and their equivalents.

Claims

1. An ion beam system comprising: a plasma source tube defining a plasma source chamber; a first gas reservoir containing a first gas and a second gas reservoir containing a second gas; a first controller fluidly coupled to the first gas reservoir and configured to control a first flow rate of the first gas and a second controller fluidly coupled to the second gas reservoir and configured to control a second flow rate of the second gas; and A first capillary contraction and a second capillary contraction, the first capillary contraction including a first end fluidly coupled to the first controller and a second end fluidly coupled to the plasma source chamber, the second capillary contraction including a third end fluidly coupled to the second controller and a fourth end fluidly coupled to the plasma source chamber, wherein the first capillary contraction and the second capillary contraction are different. 2 . The ion beam system of claim 1 , wherein the first capillary contraction and the second capillary contraction are separated from each other. 3 . The ion beam system of claim 1 , wherein the first capillary contraction and the second capillary contraction do not intersect each other.

4. The ion beam system of claim 1, wherein at least one of the first controller or the second controller comprises a variable outlet pressure valve.

5. The ion beam system of claim 1 , further comprising a first gas supply line and a second gas supply line, the first gas supply line fluidly connecting the first gas reservoir and the first controller, the second gas supply line fluidly connecting the second gas reservoir and the second controller, wherein the first controller is configured to fluidly isolate the first gas supply line from the first capillary contraction, and the second controller is configured to fluidly isolate the second gas supply line from the second capillary contraction.

6. The ion beam system of claim 1 , further comprising a bypass manifold coupled to the plasma source tube, wherein: The bypass manifold defines a bypass chamber in fluid communication with the plasma source chamber; and The second end of the first capillary contraction is coupled to the bypass manifold, and the fourth end of the second capillary contraction is coupled to the bypass manifold.

7. The ion beam system of claim 6, wherein: In a first state, the bypass manifold is coupled to the plasma source tube, and the first and second capillary contractions, the bypass chamber, and the plasma source chamber are fluidly isolated from a vacuum source: and In a second state, the bypass manifold is remote from the plasma source tube, and the first and second capillary contractions, the bypass chamber, and the plasma source chamber are in fluid communication with the vacuum source.

8. The ion beam system of claim 7, further comprising a chamber body defining an interior volume housing the plasma source tube and the bypass manifold, wherein the interior volume is in fluid communication with the vacuum source.

9. The ion beam system of claim 7, wherein: The first controller includes a first bleed port valve fluidly coupled to the vacuum source, and the second controller includes a second bleed port valve fluidly coupled to the vacuum source; and In the second state, the first controller is configured to fluidly couple the first capillary contraction to the first bleed port valve and the second controller is configured to fluidly couple the second capillary contraction to the second bleed port valve.

10. An ion beam system comprising: a plasma source tube defining a plasma source chamber; a first gas reservoir containing a first gas species and a second gas reservoir containing a second gas species; a first controller fluidly coupled to the first gas reservoir and configured to control a first flow rate of the first gas species; a first capillary contraction including a first end fluidly coupled to the first controller and a second end fluidly coupled to the plasma source chamber; and A computer system is in communication with the first controller and is configured to provide instructions for operating the first controller.

11. The ion beam system of claim 10, further comprising: a second controller fluidly coupled to the second gas reservoir and configured to control a second flow rate of the second gas species; and A second capillary contraction includes a third end fluidly coupled to the second controller and a fourth end fluidly coupled to the plasma source chamber, wherein the first capillary contraction and the second capillary contraction are separated from one another.

12. The ion beam system of claim 10, wherein the first controller comprises a variable outlet pressure valve.

13. The ion beam system of claim 10, further comprising a first gas supply line fluidly coupling the first gas reservoir and the first controller, wherein the first controller is configured to fluidly isolate the first gas supply line from the first capillary constriction.

14. The ion beam system of claim 10, further comprising a bypass manifold coupled to the plasma source tube, wherein: The bypass manifold defines a bypass chamber in fluid communication with the plasma source chamber; and The second end of the first capillary contraction is coupled to the bypass manifold.

15. The ion beam system of claim 14, wherein: In a first state, the bypass manifold is coupled to the plasma source tube, and the first capillary contraction, the bypass chamber, and the plasma source chamber are fluidly isolated from a vacuum source: and In a second state, the bypass manifold is remote from the plasma source tube, and the first capillary contraction, the bypass chamber, and the plasma source chamber are in fluid communication with the vacuum source.

16. The ion beam system of claim 15, further comprising a chamber body defining an interior volume housing the plasma source tube and the bypass manifold, wherein the interior volume is in fluid communication with the vacuum source.

17. The ion beam system of claim 15, wherein: The first controller includes a first bleed port valve fluidly coupled to the vacuum source; and In the second state, the first controller is configured to fluidly couple the first capillary contraction to the first bleed port valve.

18. A non-transitory computing device readable storage medium having computing device readable instructions of a program stored thereon, the instructions, when executed by one or more computing devices, causing the one or more computing devices to perform operations, the operations comprising: instructing a first controller to open a first variable outlet pressure valve to release a first gas from a first gas reservoir through a first capillary constriction into a plasma source chamber defined in a plasma source tube at a first flow rate; as well as A second controller is directed to open a second variable outlet pressure valve to release a second gas from a second gas reservoir into the plasma source chamber through a second capillary contraction at a second flow rate such that the first gas and the second gas mix in the plasma source chamber, wherein the second capillary contraction is different from the first capillary contraction.

19. The non-transitory computing device readable storage medium of claim 18, wherein: the first gas and the second gas are released from the first capillary contraction and the second capillary contraction, respectively, into a bypass chamber defined in a bypass manifold; The bypass manifold is coupled to the plasma source tube; and The bypass chamber is fluidly isolated from a vacuum source; and The operations also include instructing a bypass actuator to move the bypass manifold away from the plasma source tube such that the first and second capillary contractions, the bypass chamber, and the plasma source chamber are in fluid communication with the vacuum source.

20. The non-transitory computing device readable storage medium of claim 19, wherein the operation further comprises opening a first bleed port valve included in the first controller to fluidly couple the first capillary constriction to the vacuum source, and opening a second bleed port valve included in the second controller to fluidly couple the second capillary constriction to the vacuum source.

Images