Water pressure supply system for ion source

Abstract

The ion source has an arc chamber defining an arc chamber volume. A reservoir is connected to the arc chamber and defines a reservoir volume. The reservoir receives a source species and defines a liquid within the reservoir volume. A conduit fluidly connects the reservoir volume to the arc chamber volume. First and second openings of the conduit open to the respective reservoir and arc chamber volumes. A heat source selectively heats the reservoir to melt the source species at a predetermined temperature. A liquid controller controls a first volume of liquid within the reservoir volume to define a predetermined supply of liquid to the arc chamber volume. The liquid controller is a pressurized gas source fluidly connected to the reservoir to supply gas to the reservoir and a predetermined amount of liquid to the arc chamber.

Description

Detailed Description of the Invention

[0001] REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Application No. 17 / 588,999, filed January 31, 2022, entitled "HYDRAULIC FEED SYSTEM FOR AN ION SOURCE," the entire contents of which are incorporated herein by reference in their entirety.

[0002] [Technical field] FIELD OF THE DISCLOSURE The present disclosure relates generally to ion implantation systems, and more particularly to apparatus, systems and methods for supplying source material to an ion source.

[0003] [Background technology] There is an increasing demand for ion implants using metal ions. For example, aluminum implants are important to the power device market, which is a small but very fast growing segment. For many metals, including aluminum, the feed material to the ion source is an issue. While gas molecules containing aluminum or other metals can be utilized, the metal atoms tend to combine with many carbon and / or hydrogen atoms, which can cause problems for the ion source. Previously, systems have been provided that utilize a vaporizer, a small oven outside the arc chamber of the ion source, which heats the metal salt and creates enough vapor pressure to provide the vapor to the ion source. However, the oven is located remotely from the arc chamber and takes time to heat to the desired temperature, establish the vapor flow, start the plasma, start the ion beam, etc. Furthermore, if a change from one metal species to another is required, there is a waiting period until the oven cools down sufficiently to the point where no vapor from the vaporizer is present in the arc chamber.

[0004] Another conventional technique is to place a metal-containing material inside the arc chamber. In the case of aluminum implants, the metal-containing material may consist of aluminum oxide, aluminum fluoride, or aluminum nitride, all of which can withstand the temperatures of the plasma chamber at approximately 800°C. In such systems, atoms are removed from the metal-containing material by sputtering or chemical action, and the atoms enter the plasma. Etchant gases such as fluorine can be used to further chemically etch the material. Although acceptable beam currents can be achieved using these various techniques, aluminum oxide, aluminum chloride, and aluminum nitride compounds are all good electrical insulators and tend to deposit on the electrodes adjacent to the ion source in a relatively short time (e.g., 5-10 hours). This can result in a variety of adverse effects, including high voltage instability and associated variations in ion implantation yield.

[0005] 〔overview〕 Aspects of the present disclosure facilitate an ion implantation process to increase the operational life of an ion source in an ion implantation system, reduce transition times between implants of various implant species, and improve the purity of the plasma associated with each implant species. The present disclosure further increases the time between preventive maintenance cycles, increasing the overall productivity and life of the ion implantation system.

[0006] According to one embodiment of the present disclosure, an ion source for an ion implantation system is provided, the ion source including an arc chamber defining an arc chamber volume, a reservoir operatively connected to the arc chamber and defining a reservoir volume, the reservoir volume configured to contain a source species, for example, in liquid form therein, the source species being, for example, initially provided as a solid source species.

[0007] The conduit fluidly connects the reservoir volume to the arc chamber volume. The conduit has a first opening and a second opening, the first opening operably connected to the reservoir and the second opening located above the first opening and opening to the arc chamber volume. The liquid controller is further operably connected to the reservoir, the liquid controller configured to control a first volume of liquid defined within the reservoir volume. The first volume of liquid within the reservoir volume further defines a predetermined supply of liquid to the arc chamber volume.

[0008] The liquid control device may, for example, comprise a gas source fluidly connected to the reservoir, the gas source configured to selectively supply gas to the reservoir at a predetermined pressure and / or flow rate. In one embodiment, a gas pressure control device is provided and configured to control a pressure of the gas within the reservoir, the pressure of the gas defining a first volume of liquid within the reservoir volume.

[0009] In another embodiment, the liquid control device further comprises a gas exhaust orifice, the gas exhaust orifice defining a fluid connection between the reservoir volume and the external environment. The gas exhaust orifice, for example, defines a predetermined fluid conductance between the reservoir volume and the external environment. The gas flow control device may be further configured to control a flow rate of gas to the reservoir, where the flow rate and the predetermined fluid conductance define a first volume of liquid within the reservoir volume. The gas exhaust orifice may be further configured, for example, to selectively exhaust gas from the reservoir volume at a predetermined flow rate to the external environment, thereby maintaining the first volume of liquid within the reservoir volume.

[0010] According to one example embodiment, a cup is disposed within the arc chamber, the cup defining a cup volume. The second opening of the conduit is defined, for example, in a bottom surface of the cup. The cup includes, for example, a stem extending from the bottom surface of the cup and penetrating a wall of the arc chamber, the conduit is defined within the stem, and the reservoir is disposed below the cup. The liquid control device can control a second volume of liquid within the cup volume, for example, via control of a first volume of liquid within the reservoir volume.

[0011] According to another embodiment, the repeller apparatus is operably connected to a bottom of the arc chamber and a cup is defined within the repeller apparatus. The repeller apparatus can be electrically connected to the arc chamber or electrically isolated from the arc chamber, such that the repeller apparatus can be further configured to selectively heat the liquid via the plasma within the arc chamber.

[0012] In another embodiment, a heat source is provided in thermal communication with the reservoir, the heat source configured to selectively heat the reservoir. The heat source comprises, for example, one or more of an electric cartridge heater and a heat lamp operably connected to the reservoir. The heat source can be comprised of any electrical or physical heating device or source, such as an electric heater, a plasma column heater, or other heating source available to the ion source. For example, the arc chamber can comprise a sidewall defining the heat source, the sidewall of the arc chamber configured to transfer heat associated with the plasma within the arc chamber volume to the reservoir. In a particular embodiment, the reservoir is selectively connected to the arc chamber, the reservoir volume configured to selectively receive a solid source species for placement therein. In this manner, the heat source can be further configured to melt the solid source species to define a liquid.

[0013] In other examples, the liquid control device may be comprised of one or more of a bladder, a syringe, or a mechanical device configured to mechanically control the size or position of the first volume. For example, the liquid control device may include an elevator mechanism operably connected to the reservoir, the elevator mechanism selectively varying a vertical position of the reservoir relative to the arc chamber to define a predetermined supply of liquid to the arc chamber volume by gravity.

[0014] In another aspect of the present disclosure, an ion source is provided comprising an arc chamber defining an arc chamber volume. A cup is disposed within the arc chamber, the cup defining the cup volume. The cup, for example, comprises a stem extending from a bottom surface of the cup and penetrating a wall of the arc chamber. A reservoir is further operably connected to the arc chamber and defining a reservoir volume, the reservoir volume configured to contain a liquid therein.

[0015] A conduit may be defined within the stem, the conduit fluidly connecting the reservoir volume to the arc chamber volume. Additionally, a heat source is provided in thermal communication with the reservoir, the heat source configured to selectively heat the reservoir. A liquid controller is also operatively connected to the reservoir. The liquid controller is configured to control a first volume of liquid defined within the reservoir volume, the first volume of liquid within the reservoir volume further defining a second volume of liquid within the cup volume.

[0016] The liquid control device may, for example, be comprised of a pressurized gas source fluidly connected to the reservoir. The pressurized gas source in this example is configured to selectively supply gas to the reservoir. The gas exhaust orifice, for example, defines a predetermined fluid conductance between the reservoir volume and the external environment, whereby the gas flow control device is configured to control a flow rate of gas to the reservoir, where the flow rate and the predetermined fluid conductance define a first volume of liquid within the reservoir volume.

[0017] The reservoir can be selectively connected, for example, to a bottom of the arc chamber, the reservoir volume configured to selectively receive a solid source species for placement therein, and the heat source configured to melt the solid source species to define a liquid.

[0018] According to yet another exemplary aspect, an ion source for an ion implantation system is provided, the ion source comprising an arc chamber defining an arc chamber volume. A reservoir is selectively operably connected to a bottom of the arc chamber defining a reservoir volume, the reservoir configured to selectively receive a solid source species for placement within the reservoir volume. A repeller apparatus is further operably connected to the arc chamber, the repeller apparatus comprising a cup defining a cup volume. The repeller apparatus, for example, comprises a stem extending from a bottom surface of the cup and penetrating a bottom surface of the arc chamber, whereby a conduit is defined within the stem, the conduit fluidly connecting the reservoir volume to the arc chamber volume. A heat source is further provided in thermal communication with the reservoir, the heat source configured to selectively heat the reservoir and melt the solid source species to define a liquid.

[0019] In this exemplary embodiment, the liquid control device is further operably connected to the reservoir, the liquid control device configured to control a first volume of liquid defined within the reservoir volume. The first volume of liquid within the reservoir volume further defines a second volume of liquid within, for example, a cup volume. The liquid control device can include, for example, a pressurized gas source fluidly connected to the reservoir, the pressurized gas source configured to selectively supply gas to the reservoir. The gas exhaust orifice, for example, defines a predetermined fluid conductance between the reservoir volume and the external environment, whereby the gas flow control device controls a flow rate of gas to the reservoir. The flow rate of gas and the predetermined fluid conductance, for example, defines a first volume of liquid within the reservoir volume.

[0020] The above summary is intended merely to outline some features of some embodiments of the present disclosure, other embodiments may comprise additional and / or different features from those described above. In particular, this summary should not be construed as limiting the scope of the present application. Thus, to the accomplishment of the foregoing and related ends, the present disclosure comprises the features hereinafter described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the present disclosure. However, these embodiments are indicative of some of the various ways in which the principles of the present disclosure may be employed. Other objects, advantages and novel features of the present disclosure will become apparent from the following detailed description of the disclosure when considered in conjunction with the drawings. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a block diagram of an exemplary vacuum system in accordance with some aspects of the present disclosure. [Diagram 2] FIG. 1 is a schematic diagram of an ion source according to various embodiments of the present disclosure. [Figure 3A] 1A-1D are schematic diagrams of an ion source having source material at various stages of introduction into a source chamber in accordance with various embodiments of the present disclosure. [Figure 3B] 1A-1D are schematic diagrams of an ion source having source material at various stages of introduction into a source chamber in accordance with various embodiments of the present disclosure. [Figure 3C] 1A-1D are schematic diagrams of an ion source having source material at various stages of introduction into a source chamber in accordance with various embodiments of the present disclosure. [Figure 4A] 1 is a schematic diagram illustrating a reservoir level sensor according to various embodiments of the present disclosure. [Figure 4B] 1 is a schematic diagram illustrating a reservoir level sensor according to various embodiments of the present disclosure. [Figure 4C] 1 is a schematic diagram illustrating a reservoir level sensor according to various embodiments of the present disclosure. [Diagram 5] 1 is a partial cross-sectional view of an ion source according to various embodiments of the present disclosure. [Figure 6] 5 is a flow chart illustrating an exemplary method for forming ions from a solid source material according to another embodiment of the present disclosure.

[0022] Detailed Description The present disclosure is directed generally to various apparatus, systems, and methods related to implanting ions into a workpiece. More specifically, the present disclosure is directed to an ion source configured to supply a liquid metal into an arc chamber for extraction of ions therefrom.

[0023] Thus, the present disclosure will now be described with reference to the drawings, where like reference numerals may be used to refer to like elements throughout. It should be understood that the description of these aspects is merely illustrative and should not be construed in a limiting sense. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that the present disclosure can be practiced without these specific details. Furthermore, the scope of the present disclosure is not intended to be limited by the embodiments or examples described below with reference to the accompanying drawings, but only by the appended claims and their equivalents.

[0024] It should also be noted that the drawings are provided to provide illustrations of some aspects of the embodiments of the present disclosure and are therefore to be considered as schematic only. In particular, the elements shown in the drawings are not necessarily to scale relative to each other, and the arrangement of various elements in the drawings has been selected to provide a clear understanding of the respective embodiments and should not necessarily be interpreted as representing the actual relative positions of various components in implementations according to the embodiments of the present disclosure. Furthermore, the features of the various embodiments and examples described herein can be combined with each other, unless otherwise specified.

[0025] It should also be understood that in the following description, direct connections or couplings between functional blocks, devices, components, circuit elements, or other physical or functional units shown in the drawings or described herein may also be implemented by indirect connections or couplings. Furthermore, it should also be understood that functional blocks or units shown in the drawings may be implemented as separate functions, circuits, or components in one embodiment and fully or partially implemented in a common function, circuit, or component in another embodiment. Furthermore, for example, some functional blocks may be implemented as software running on a common processor or controller.

[0026] In the manufacture of semiconductor devices, ion implantation is performed to dope semiconductors with impurities. Ion implantation systems are often utilized to dope workpieces, such as semiconductor wafers, with ions from an ion beam to produce doping of n-type or p-type materials or to form passivation layers during the manufacture of integrated circuits. Such beam processes are often used to selectively implant impurities of a given dopant material into a workpiece at a predetermined energy level and at a controlled concentration to produce a desired semiconductor material during the manufacture of integrated circuits. For example, when used to dope semiconductor wafers, ion implantation systems implant selected ion species into the workpiece to produce a desired extrinsic material. For example, implanting ions generated from source materials such as antimony, arsenic, and phosphorus results in an "n-type" extrinsic material wafer, while "p-type" extrinsic material wafers are often obtained from ions generated from source materials such as boron, gallium, and indium.

[0027] An ion implanter includes an ion source, an ion extraction device, a mass analysis device, a beam transport device, and a workpiece processing device. The ion source produces ions of the desired atomic or molecular dopant species. These ions are extracted from the ion source by an extraction system, such as an electrode that is energized to direct the flow of ions from the ion source to form an ion beam. The desired ions are separated from the ion beam with a mass analysis device, such as a magnetic dipole, which performs mass dispersion or separation of the extracted ion beam. A beam transport device, such as a vacuum system including a series of focusing devices, transports the ion beam to a workpiece processing device while maintaining the desired characteristics of the ion beam. Finally, a workpiece, such as a semiconductor wafer, is transferred to or from the workpiece processing device via a workpiece handling system. The workpiece handling system may include one or more robotic arms for positioning the workpiece to be processed in front of the ion beam and removing the processed workpiece from the ion implanter.

[0028] The present disclosure appreciates the interest in novel species for use in ion implantation. A variety of non-traditional elements have been considered for use in ion implantation, e.g., gallium (Ga), aluminum (Al), indium (In), lanthanum (La), tin (Sn), and selenium (Se), and these non-traditional elements share several common attributes. For example, convenient and simple gaseous compounds containing such elements are not readily available, and the elements have melting temperatures that approximate temperatures typically found in the vicinity of the ion source of an ion implanter (e.g., room temperature up to about 900° C.). Furthermore, the molten elements generally have low vapor pressures (e.g., less than a few mtorr) at such temperatures associated with ion sources.

[0029] Two common approaches have traditionally been utilized to generate ions from such species: vaporizers and solid targets. For example, if a suitable salt or other compound containing the element is present, the element may first be heated in an oven to vaporize it into the gas phase, and the vapor may then be delivered to the ion source chamber through a communication channel connecting the oven and the ion source chamber. Such ovens are commonly used when aluminum is selected as the ion species, and compounds such as aluminum iodide (AlI3) or aluminum chloride (AlCl3) may be utilized along with a vaporizer. However, vaporizers generally have long warm-up and cool-down times, and because there are no valves in the communication channel between the oven and the ion source chamber, it takes a lot of time (e.g., 20-30 minutes) to melt and / or vaporize the compound before delivering the vaporized material to the ion source chamber, and a similar amount of time to transition to cool-down.

[0030] Additionally, material vaporized from the compounds may contain undesirable atoms such as Fluorine (F), Chlorine (Cl), Oxygen (O), etc., which can dramatically reduce the beam current and / or coat electrically active components of the ion implanter with by-products, thus causing instability and shortening the lifetime of the ion source.

[0031] Another approach to producing ions from such ion species is to identify a compound of the element with a high melting point and provide that compound as a solid target in the ion source. For example, for aluminum ion species, aluminum nitride (AlN) or aluminum oxide (Al2O3) targets are known not to melt at typical ion source temperatures. Such targets can be placed in the ion source chamber, where the target is held in the plasma column, placed in a pocket in the sidewall of the ion source chamber, or held in the ion source repeller. Atoms of the desired element can then be incorporated into the plasma by physical sputtering or chemical etching of the target by the plasma generated in the ion source. However, such approaches are limited by the physical amount of solid source material contained in the ion source, as well as the presence of additional atoms in the target can reduce the beam current or produce undesirable by-products that shorten the ion source's lifetime.

[0032] This disclosure recognizes that efforts have been made by using a material held within a cup-like repeller within the arc chamber, the repeller being covered by a cap with a hole through the cap, as disclosed in commonly owned U.S. Pat. No. 11,170,967, the entire contents of which are incorporated herein by reference. Such an approach uses a combination of vaporization of the material to deliver the gas and surface tension to attract the liquid to the surface of the cap exposed to the plasma to deliver the liquid material directly to the ion source chamber. Such an approach has demonstrated high current capabilities. However, the amount of material that can be held within the cup is limited, and the flow of the liquid is difficult to control and is affected by plasma parameters. Furthermore, it can be difficult to stop the flow of material from the cup when different species are desired to flow, and such an approach is best suited for systems where the axis defined between the cathode and the repeller is vertical.

[0033] The present disclosure appreciates the desire to provide systems, devices, and methods for controlling the introduction or flow rate of pure elements into an ion source from a reservoir having a large capacity, where the reservoir is large enough to last at least the life of the ion source, and where fast switching capabilities are provided for changing between different ion species.

[0034] To provide a general understanding and context for the present disclosure, an exemplary vacuum system 100 is shown in Figure 1. In this example, the vacuum system 100 comprises an ion implantation system 102, although various other types of vacuum systems are contemplated, such as a plasma processing system or other semiconductor processing system. The ion implantation system 102 includes, for example, a terminal 104, a beamline assembly 106, and an end station 108.

[0035] In general, an ion source 110 in the terminal 104 is connected to a power supply 112, which provides a supply of source material 114 (also called dopant material) to an arc chamber 116, which is ionized into a plurality of ions to form an ion beam 118, which passes through an extraction aperture 120 and is extracted. The ion beam 118 in this example passes through a beam steering device 122 (also called a source magnet) and exits through an aperture 124 towards an end station 108. At the end station 108, the ion beam 118 is directed at a workpiece 126 (e.g., a semiconductor such as a silicon wafer, display panel, etc.) that is selectively clamped or attached to a chuck 128 (e.g., an electrostatic chuck or ESC). When embedded in the lattice of the workpiece 126, the implanted ions change the physical and / or chemical properties of the workpiece. For this reason, ion implantation is used in semiconductor device manufacturing and metal finishing, as well as for various applications in materials science research.

[0036] The ion beam 118 of the present disclosure may take any form, such as a pencil or spot beam, a ribbon beam, a scanning beam, or any other form in which ions are directed toward the end station 108, and all such forms are contemplated as being within the scope of the present disclosure.

[0037] According to one exemplary embodiment, the end station 108 comprises a process chamber 130, such as a vacuum chamber 132, and a process environment 134 associated with the process chamber. The process environment 134 generally resides within the process chamber 130 and, in one embodiment, comprises a vacuum generated by a vacuum source 136 (e.g., a vacuum pump) connected to the process chamber and configured to substantially evacuate the process chamber. Additionally, a controller 138 is provided for overall control of the vacuum system 100 and its components.

[0038] It should be understood that the systems, apparatus, and methods of the present disclosure may be implemented in other semiconductor processing equipment, such as CVD equipment, PVD equipment, MOCVD equipment, etching equipment, and various other semiconductor processing equipment, and all such implementations are contemplated as falling within the scope of the present disclosure. The present disclosure provides systems, apparatus, and methods that advantageously increase the usage period of the ion source 110 between preventive maintenance cycles, thus increasing the overall productivity and life of the vacuum system 100.

[0039] The arc chamber 116 of the ion source 110 is shown, for example, in schematic form in FIG. 2, whereby the ion source of the present disclosure may be configured to provide the ion beam 118 of FIG. 1. High beam currents are thereby achieved by providing the source material 114 to the arc chamber 116 in a novel manner in pure, elemental, solid form, as opposed to providing a gaseous compound or solid target as is conventional. For example, in accordance with the present disclosure, the source material 114 may be initially provided to the ion source 110 of FIG. 2 in solid form and may be comprised of elemental aluminum, indium, gallium, lanthanum, tin, antimony, or other elements useful for ion implantation. For example, pure elemental materials may be used, with alloys being preferred where the alloy has a more convenient melting temperature. It is further noted that while the source material 114 is described in one embodiment as being an elemental metal, the source material may be comprised of any metallic or non-metallic element, combination element or compound, and all such source materials are contemplated as falling within the scope of the present disclosure.

[0040] 2, the arc chamber 116 generally defines an arc chamber volume 140 in which a plasma 142 is formed from the source material 114. According to one exemplary embodiment, a reservoir 144 (e.g., a crucible) is operably connected to the arc chamber 116, where the reservoir generally defines a reservoir volume 146. The reservoir 144 is configured to contain, for example, the source material 114 in liquid form within the reservoir volume 146.

[0041] The reservoir 144 may further be selectively connected, for example, to one or more side walls 148A-148E of the arc chamber 116. In this embodiment, the reservoir 144 is operably connected to the bottom side wall 148A of the arc chamber 116. However, it should be noted that the present disclosure contemplates that the reservoir 144 may be operably connected to any of the one or more side walls 148A-148E of the arc chamber 116 (e.g., bottom, top, left, right, front, rear, or other walls), whereby the reservoir may be directly or indirectly connected to one or more side walls and may be either stationary or translating relative to the arc chamber.

[0042] The reservoir volume 146 is selectively accessible, for example, to selectively place and contain the source material 114 (e.g., in solid form) therein. For example, one or more fasteners 150 (e.g., one or more bolts, latches, screws, levers, plates, or other connection devices) may be provided for selectively accessing the reservoir volume 146 to selectively operably connect the reservoir 144 to the arc chamber 116. In this embodiment, the reservoir 144 can be selectively removed from the arc chamber 116 so that the source material 114 can be placed within the reservoir volume, and the reservoir can then be reconnected to the arc chamber.

[0043] In one embodiment, a heat source 152 is further provided in thermal communication with the reservoir 144. The heat source 152, in one embodiment, is controllable and configured to selectively heat the reservoir to a predetermined temperature associated with the source material 114 becoming in a liquid state. The predetermined temperature can be based, for example, on a selection of the source material 114, whereby the predetermined temperature is equal to or greater than the melting point of the selected source material 114 disposed within the reservoir volume 146.

[0044] The heat source 152 may consist of, for example, one or more electric heaters operably connected to the reservoir 144, as discussed in further detail below. Note that the present disclosure contemplates the heat source 152 as consisting of any heat source, such as radiant heat lamps, heat pumps, heat associated with the plasma 142 formed within the arc chamber 116, or any other heating device in thermal communication with the reservoir 144. The reservoir 144 may, for example, be thermally connected to the arc chamber 116, whereby the heat associated with the plasma 142 provides heating of the source material 114 within the reservoir. In this manner, the arc chamber 116 may itself act as a heat source 152, whereby the formation of the plasma 142 selectively heats the reservoir 144 via the transfer of heat through the bottom sidewall 148A of the arc chamber. In another embodiment, connection of the reservoir 144 to the arc chamber 116 can advantageously augment the heating provided by the electric heater described above such that the source material 114 in the reservoir 144 is heated to or maintained in a liquid state.

[0045] This disclosure further appreciates that, based on the selection of source material 114 and the ambient temperature of the environment associated with terminal 104 of FIG. 1, heat source 152 may be omitted. As such, source material 114 may be provided as a liquid in reservoir 144, such that no additional heating of the source material is required to maintain the liquid state. Source material 114 may be comprised of, for example, gallium, indium, or other materials having melting temperatures near room temperature, such that no additional heating is required to maintain the source material in a liquid state.

[0046] 2 illustrates a conduit 154 fluidly connecting the reservoir volume 146 to the arc chamber volume 140. For example, the conduit 154 includes a first opening 156 and a second opening 158, the first opening being operatively connected to the reservoir 144 and opening into the reservoir volume 146, and the second opening being located vertically above the first opening and opening into the arc chamber volume 140.

[0047] For example, liquid controller 160 is further operatively connected to reservoir 144, where liquid controller 160 is configured to control a first volume 162 of source material 114 defined within reservoir volume 146 when the source material is in a liquid state. Controlling first volume 162 of source material 114 within reservoir volume 146 defines a predetermined supply of source material to arc chamber volume 140, for example, via transfer of source material from between first opening 156 and second opening 158 of conduit 154. Source material 114 is further vaporized within arc chamber 116 to form plasma 142. Source material 114 is, for example, directly exposed to arc chamber volume 140.

[0048] In one embodiment, a cup 164 is further disposed within the arc chamber 116, the cup generally defining a cup volume 166 exposed to the arc chamber volume 140. A second opening 158 of the conduit 154 is defined, for example, in a bottom surface 168 of the cup 164 and opens into the cup volume 166, such that source material can be further transferred between the reservoir volume 146 and the cup volume 166 via the liquid control device 160. For example, the cup 164 includes a stem 170 extending from the bottom surface 168 of the cup and penetrating a bottom sidewall 148A of the arc chamber 116, the conduit 154 being defined within the stem, and the reservoir 144 being disposed below the cup. The liquid control device 160 thus controls, for example, a second volume 172 of source material 114 within the cup 164 volume via control of the first volume 162 of source material within the reservoir volume 146.

[0049] According to one embodiment, the liquid controller 160 comprises a pressurized fluid source 174 fluidly connected to the reservoir 144. The pressurized fluid source 174 is configured to selectively supply a fluid, such as, for example, a gas, to the reservoir 144 at a predetermined pressure and / or flow through a supply orifice 176 associated with the reservoir, the pressure within the reservoir 144 defining a first volume 162 of the source material 114 within the reservoir volume 146. The liquid controller 160 can thus, for example, further control the second volume 172 of the source material 114 within the cup volume 166 via a pressure differential between the pressurized fluid source 174 and the pressure within the arc chamber volume 140. In a preferred embodiment, the fluid supplied by the pressurized fluid source 174 comprises an inert gas, such as argon or other gas. However, the present disclosure further contemplates that the pressurized fluid source may supply any fluid (e.g., gas or liquid) that is non-reactive with the source material 114 and generally not detrimental to the desired formation and / or composition of the ion beam 118.

[0050] A gas exhaust orifice 178 may be further provided, for example, in association with the reservoir 144, where the gas exhaust orifice defines a fluid connection between the reservoir volume 146 and an external environment 180. The external environment 180 may be associated, for example, with an environment external to the arc chamber 116 or with the arc chamber volume 140 within the arc chamber 116. The gas exhaust orifice 178 may be further configured, for example, to selectively exhaust gas from the reservoir volume 146 to the external environment 180, thereby controlling the first volume 162 of liquid within the reservoir volume. In this manner, control of the second volume 172 of source material 114 within the cup 164 may be further controlled via a pressure differential between the pressurized fluid source 174, the pressure within the arc chamber volume 140, and the flow of gas through the gas exhaust orifice 178.

[0051] The gas exhaust orifice 178 can be sized, for example, to define a predetermined gas conductance between the reservoir volume 146 and the external environment 180. For example, the ion source 110 and / or ion implantation system 102 of FIG. 1 can be configured to have an acceptable tolerance of approximately 1 sccm of additional gas flow into the system before adverse consequences are experienced from pressure or material changes within the system. Thus, the gas exhaust orifice 178 can be sized to provide less than the aforementioned 1 sccm of gas flow to provide a predetermined gas conductance from the reservoir volume 146 and the external environment 180 without adverse effects to the remainder of the system.

[0052] Thus, in this embodiment, the liquid control device 160 may further comprise a flow control device 182 (e.g., a mass flow controller) configured to control the flow of gas provided from the pressurized fluid source 174 to the reservoir volume 146, whereby the gas is exhausted through the gas exhaust orifice 178. Based on a predetermined gas conductance associated with the gas exhaust orifice, the flow control device 182 may thus advantageously control the pressure differential between the reservoir volume 146 and the external environment 180, thereby driving the flow of the source material 114 between the first volume 162 and the second volume 172.

[0053] For example, for a given size of gas exhaust orifice 178, the pressure in reservoir volume 146 is controlled via a controller that controls the flow rate of gas into the reservoir volume. If the pressure in reservoir volume 146 is greater than a predetermined allowable pressure, the flow rate of gas can be reduced via flow controller 182 to allow excess gas to vent or escape through exhaust orifice 178 until the predetermined allowable pressure is reached. For example, vacuum source 136 of FIG. 1 can further remove excess gas from the system.

[0054] 2 and / or to regulate the flow of source material 114 between the first volume 162 and the second volume 172 based on feedback associated with the flow controller 182. Thus, the liquid controller 160 may be further controlled to provide a desired amount of supply source material 114 in one or more of the first volume 162 and the second volume 172.

[0055] The present disclosure further provides for removal of source material 114 from the second volume 172 in the cup 164 of FIG. 2, for example, such that stopping or reducing the flow of gas via the flow control device 182 can quickly empty or transfer the source material from the second volume to the first volume 162 (e.g., over a period of a few seconds), thereby allowing the gas to more freely exit the reservoir 144 via the exhaust orifice 178.

[0056] It should be noted that the present disclosure further contemplates controlling the pressure in the reservoir volume 146 to control the second volume 172 of source material 114 in the cup 164, thereby eliminating the exhaust orifice 178 and controlling the pressure by a pressure controller (not shown) instead of the flow control device 182.

[0057] According to another exemplary embodiment of the present disclosure, the cup 164 further defines or is a component of a repeller device 184 operably connected to the arc chamber 116. The repeller device 184 may be negatively biased with respect to the arc chamber 116, for example, by a bias voltage 186 (e.g., 0-500 V) provided by a repeller power supply 188. For example, the bias voltage 186 (e.g., repeller supply voltage) may be altered in response to changes in the arc current, extraction current, or other factors for control purposes. For example, the controller 138 of FIG. 1 may control the bias voltage 186, input parameters to the source magnet 122, and / or other parameters associated with the plasma 142 of FIG. 2, such that the amount of power from the plasma may be controlled and delivered to the source material 114 in the cup 164, thus raising its temperature sufficiently high for the vapor pressure to sustain the plasma in the arc chamber 116.

[0058] To further maintain the plasma 142, for example, a support gas 190 can be optionally introduced into the arc chamber 116, whereby the support gas can be inert (e.g., argon) or chemically reactive (e.g., fluorine, chlorine) with the source material 114. The support gas 190 can further increase the efficiency of the ion source 110, for example, by sputtering material that condenses on one or more walls 148 (also referred to as sidewalls) generally surrounding the arc chamber 116 and converting the sputtered material back into the plasma 142. The bias voltage 186 can be further provided, controlled, or augmented by, for example, an arc voltage 192 (e.g., 0-150 V) applied to a cathode 194 associated with the arc chamber 116.

[0059] Thus, according to various aspects of the disclosure, the heat source 152, comprising heat and / or additional heaters associated with the arc chamber 116 of the ion source 110, is configured to melt and / or maintain a liquid state of the source material 114 comprising the desired elements for ionization in a reservoir 144 disposed proximate to the arc chamber, whereby the hydrostatic pressure associated with the liquid control device 160 is utilized to introduce the desired elements into the arc chamber at a controlled rate. The disclosure provides, for example, that a reduction in pressure provided by the liquid control device 160 can relatively quickly control the second volume 172 of the source material 114 provided in the arc chamber volume 140, such that the source material flows (e.g., by gravity) from the cup 164 through the conduit 154 back to the reservoir 144, thereby depleting the second volume 172 to zero, advantageously reducing material waste when switching from one ion species to another. In this manner, when it is desired to change operation of the ion source 110 from a first source material 114 to a second source material, wasteful use of the first source material can be avoided and the output of the second source material can be maximized.

[0060] According to various exemplary aspects of the disclosure, FIGS. 3A-3C show a simplified example of an ion source 200 including a reservoir 202 (e.g., a crucible) operably connected to an arc chamber 204. In operation, the reservoir 202 can be loaded with source material 206 at room temperature in FIG. 3A. For example, the source material 206 is in a solid form 208 (e.g., a solid block, powder, granules, pellets, shot, etc.) when provided to the reservoir, the source material comprising or configured with the desired elements for implantation. For example, the reservoir 202 generally defines a first chamber 210 (e.g., a first volume) and a second chamber 212 (e.g., a second volume). In this example, a partition 214 is disposed between the first chamber 210 and the second chamber 212. As shown in FIG. 3A, the first chamber 210 can be filled with source material 206 in solid form 208 (e.g., pellets, powder, shot, etc.), which can flow into the second chamber 212. The divider 214 can comprise a heat source 216, such as, for example, an electric heating element. The heat source 216 can be further provided separately from the divider 214. Alternatively, when implanting ions from a source material 206 having a low melting point (e.g., gallium), the divider 214 can comprise, for example, a fin without a heating element associated therewith. The second chamber 212 is fluidly connected to the arc chamber 204 by a conduit 218, which in one embodiment comprises or includes a flow throttling device 220, such as a capillary, a restrictive opening, or a metal mesh or porous structure.

[0061] 3A-3C are illustrated as being directly connected to the arc chamber 204, it should be noted that the reservoir can be indirectly connected to the arc chamber such that the reservoir is generally isolated from the arc chamber while still being fluidly connected to the arc chamber via a conduit 218. For example, based on the orientation of the reservoir 202 relative to the orientation of the arc chamber 204, the conduit 218 can be an elongated channel, a tube, and / or can include one or more bends and runs. The heat source 216 can be further configured to selectively heat the conduit 218, for example, such that the conduit can be further heated by a resistive heating apparatus or other heating device (not shown), which can be separate from the heating of the reservoir 202.

[0062] The heat source 216 is configured to, for example, initially melt the source material 206 in solid form 208 of FIG. 3A to transform the source material into liquid form 222, as illustrated in FIG. 3B. In this embodiment, the first chamber 210 of the reservoir 202 is further fluidly connected to a liquid control device 224, such as a gas source 226, whereby the liquid control device is configured to control the volume of liquid defined in the first chamber 210 of the reservoir 202, and thus further control the volume of liquid in the second chamber 212 of the reservoir. The gas source 226 can, for example, first be evacuated and brought to a low pressure (e.g., 5 mtorr) before supplying gas to the first chamber 210. Although not illustrated, the liquid control device 224 can alternatively comprise a gas box, another fluid source, a bladder, a hydraulic ram, an elevator, or other mechanism configured to control the respective volumes within the reservoirs 202.

[0063] In one example, the liquid control device 224 can include an elevator mechanism 227 (e.g., one or more of a piston / cylinder arrangement, a linear actuator, a lever, or other mechanism) operably connected to the reservoir 202, the elevator mechanism configured to selectively vary the vertical position of the reservoir relative to the arc chamber 204 to define a predetermined supply of source material 206 to the arc chamber by gravity.

[0064] In one embodiment, a gas such as argon, or one or more other gases that do not chemically interact with the source material 206, is supplied to the first chamber 210 of the reservoir 202 from a gas source 226. A partition 214, for example, generally separates the first chamber 210 from the second chamber 212 and extends from a top 228 of the reservoir 202 to approximately a bottom 230 of the reservoir, such that the gas source 226 can selectively provide a pressure differential that lowers a first level 232 of the source material 206 in the first chamber and raises a second level 234 of the source material in the second chamber, as illustrated in FIG.

[0065] According to one embodiment, a temperature sensing device 236 is provided and may be configured to monitor the temperature of the reservoir 202 or the source material 206 for feedback in heating the source material. In an alternative example, the heat source 216 may be configured to monitor or infer the temperature of the source material 206 in the reservoir 202.

[0066] According to one embodiment, a valve arrangement 238 is provided in association with the first chamber 210, the second chamber 212, and the arc chamber 204. The valve arrangement 238 provides a first pressure 240 associated with the first chamber that can be equal to or slightly elevated from the arc chamber pressure 242 (e.g., about 0.1 torr or less) when, for example, melting the source material 206 from the solid form 208 of FIG. 3A to the liquid form 222 of FIG. 3B. The first chamber 210 can be selectively fluidly connected to the arc chamber 204 such that the first chamber and the arc chamber are at a common pressure when melting the source material 206 to the liquid form 222 shown in FIG. 3B. When the source material 206 is in its liquid form 222, the first chamber 210 can be held at a low pressure such that a pressure differential between the first chamber and the second chamber 212 has only a small effect on the level of the source material in either chamber.

[0067] 3C, gas from the gas source 226 is supplied to the first chamber 210 at a second pressure 244, which is greater than the arc chamber pressure 242. The second pressure 244 may be, for example, in the range of 1 to 25 torr, but the pressure may vary depending on various facts such as the shape of the reservoir 202, the location of the reservoir relative to the arc chamber 204, and the density of the source material 206 in liquid form 222. Thus, the pressure difference between the first chamber 210 and the second chamber 212 of the reservoir raises the level in the second chamber relative to the level in the first chamber, thereby forcing the source material 206 through the conduit 218 and into the arc chamber 204.

[0068] The present disclosure appreciates that for control purposes, it may be advantageous to vent a portion of the gas supplied to the first chamber of the reservoir 202 to a pump system (not shown) such that the second pressure 244 is automatically reduced unless a constant supply of gas is provided from the gas source 226 to the first chamber 210. Additionally, the present disclosure contemplates various other devices and methods for controlling and / or applying the first pressure 240 and the second pressure 244 to the first chamber 210 of the reservoir. For example, if the first chamber 210 is maintained as a closed system, the gas within the first chamber may be heated to increase the pressure from the first pressure 240 to the second pressure 244, or the volume of the first chamber 210 may be reduced to increase the pressure, such as via a bladder, syringe, movable or deformable wall (not shown), whereby hydrodynamic action provides the fluctuation in pressure. Additionally, the reservoir 202 may itself be physically moved vertically relative to the arc chamber 204 such that the level of the supply source within the first chamber 210 is controlled by the positional height of the reservoir.

[0069] In an example where the source material 206 includes gallium, a pressure difference between the first chamber 210 and the second chamber 212 of about 10 torr will cause the liquid level in the second chamber to rise by about 40 mm. Because the liquid form 222 of the source material 206 in this elemental form is significantly denser than gases typically used for implantation source materials, a relatively low flow rate of the elemental source material of the present disclosure through the conduit is sufficient. For example, in the case of gallium, a liquid flow rate of 3e-3 cc / min of the liquid material will introduce the same amount of gallium into the arc chamber 204 as a gas flow rate of 5 sccm (assuming) of pure gallium in gas form. Thus, a reasonably sized reservoir with internal dimensions of about 30 mm x 30 mm x 20 mm will contain enough material to provide the equivalent of 100 hours of gas flow at a flow rate of 5 sccm.

[0070] When it is desired to stop operation of the arc chamber 204 or to change from a first type to a second type of source material 206, the second pressure 244 shown in FIG. 3C in the first chamber 210 can be lowered by active pumping or by selectively allowing evacuation or venting of gas to the atmosphere or vacuum environment in which the ion source 200 resides. As the pressure difference between the first chamber 210 and the second chamber 212 decreases, the liquid level in the second chamber drops and source material 206 is no longer supplied to the arc chamber 204 through the conduit 218. Additionally, any source material 206 present in the arc chamber 204, such as may be present in the cup 164 of FIG. 2, is thus allowed to return by gravity to the second chamber 212 of FIG. 3C.

[0071] The present disclosure further appreciates that it may be advantageous to measure the amount of source material remaining in the reservoir 202. As such, one or more level sensors 250 may be provided, as illustrated in FIG. 3C. It should be noted that one or more level sensors 250 may be provided in association with one or more of the first chamber 210 and the second chamber 212 to measure the respective levels of the source material 206 therein. The one or more level sensors 250 may, for example, comprise one or more conductive probes 252 extending into the source material 206 in the first chamber 210. Based at least in part on the length of each probe 252, electrical continuity, resistance, or capacitance between each probe and the source material 206 may be measured. For example, a single probe 252 extending proximate to the bottom 230 of the reservoir 202 may be utilized to simply determine a "low level" or "empty level" of the source material 206 in the reservoir, while multiple probes of different lengths may be utilized to determine a range of levels of source material in the reservoir.

[0072] In another embodiment, for a conductive source material 206, a level sensor 300 is shown in Figures 4A-4C whereby two parallel conductive traces 302 are deposited on an insulating refractory material 304, such as alumina or boron nitride. When the traces are below the surface 308 of the source material, fluctuations in the level of the source material 306 electrically short the traces 302, thus lowering the resistance of the level sensor below the resistance of the traces themselves. For example, Figure 4A shows the source material 306 contacting the traces 302, thus indicating a full level 310, Figure 4B shows a low level 312 of source material contacting the traces, and Figure 4C shows an empty level 314 of source material. As the level of source material 306 decreases, the resistance 316 measured between the traces 302 increases to a value associated with the empty level 314. The resistance 316 may be based, for example, on the temperature and source material 306 utilized, but is a repeatable function for a given material. For example, the level sensor 300 of FIGS. 4A-4C is suitable for conductive materials such as Ga, In, Sn, Zn, Sb, Al, La, and Pb.

[0073] The present disclosure further contemplates various arrangements of the reservoir in a myriad of configurations. For example, the reservoir 202 shown in Figures 3A-3C is illustrated generally as one example, but other configurations are contemplated, such as where the first chamber 210 and the second chamber 212 are concentrically arranged, as illustrated in Figure 5. However, it should be noted that all configurations provided herein are only some examples of what is contemplated, and the present disclosure contemplates various other structural configurations of the arc chamber and ion source as further within the scope of the present disclosure.

[0074] 5, for example, an ion source 400 is shown having an arc chamber 402 generally defining an arc chamber volume 404. A cup 406, for example, is disposed within the arc chamber 402, the cup defining a cup volume 408. The cup 406 includes a stem 410, for example, extending from a bottom surface 412 of the cup and penetrating a wall 414 of the arc chamber 402.

[0075] Additionally, a reservoir 416 is operably connected to the arc chamber 402 and generally defines a reservoir volume 418. The reservoir volume 418 is configured to contain, for example, a source material 420 therein, the source material being initially in solid form. For example, a conduit 422 is defined within the stem 410, the conduit fluidly connecting the reservoir volume 418 to the arc chamber volume 404 via the cup volume 408.

[0076] The heat source 424 may be in thermal communication with the reservoir 416, for example, and configured to selectively heat the reservoir, such that the heat source converts and / or maintains the source material 420 in a liquid form. The heat source 424 may include, for example, one or more electric heaters 426 operably connected to the reservoir 416. The one or more electric heaters 426 may comprise, for example, one or more cartridge heaters embedded in the structure of the reservoir 416, such that the reservoir may include one or more of graphite, boron nitride, alumina, tungsten, or another refractory material. Additionally, one or more thermocouples 428 may be provided in thermal contact with the reservoir 416 to provide control of the heat source 424.

[0077] For example, the liquid controller 430 is further operably connected to the reservoir 416, where the liquid controller is configured to control a first volume 432 of source material 420 in liquid form defined within the reservoir volume 418. The first volume 432 of source material 420 in liquid form within the reservoir volume, as controlled by the liquid controller 430, further defines a second volume 434 of source material within the cup volume 408.

[0078] The liquid control device 430 may, for example, comprise a pressurized gas source 436 fluidly connected to the reservoir 416, the pressurized gas source configured to selectively supply gas to the reservoir at a predetermined pressure. The predetermined pressure supplied by the pressurized gas source 436 may, for example, define a first volume 432 of liquid in the reservoir volume 418, and thus further define a second volume 434 of liquid in the cup volume 408. In this manner, the level of source material 420 in the cup 406 is based, at least in part, on the predetermined pressure provided by the pressurized gas source 436.

[0079] A pressurized gas source 436 can, for example, provide argon or another gas through a top 438 of the reservoir 416, forcing the source material 420 through a conduit 422 and into the arc chamber volume 404, where the source material defines a second volume 434 within the cup 406. The cup 406 can, for example, comprise a repeller 440, as described above. The area of ​​the cup 406 defining the top surface of the second volume 434 can be sized, for example, to maximize the available beam current associated with ion implantation.

[0080] Additionally, the reservoir 416 and repeller 440 may be electrically isolated from the remainder of the arc chamber 402 and biased relative to the arc chamber. Thus, heating of the repeller 440 by ions from the plasma can further advantageously control the heating of the source material 420 within the arc chamber 402, thereby allowing the present disclosure to provide multiple heat sources to the source material.

[0081] The present disclosure further appreciates that, for example, controlling the size (e.g., length and diameter) of the conduit 422 can provide further control of the flow of source material 420 therethrough. Additionally, the present disclosure appreciates that a static pressure can be implemented on the pressurized gas source 436 to control the level of source material 420 in the cup 406. However, a dynamic system can alternatively be implemented whereby gas is continuously fed through the top 438 of the reservoir 416, and gas is further permitted to be exhausted through head space 442 and pumped through the arc chamber 402 to the orifice 444. The orifice 444 can be sized to controllably maintain the pressure in the head space 442 over a range of up to 100 torr while maintaining the gas flow rate at a level below 10 sccm. Alternatively, a needle valve (not shown) can be provided with the pressurized gas source to further control the flow of gas and therefore the pressure and level of source material in the reservoir 416.

[0082] The present disclosure thus provides a source material to an arc chamber of an ion implantation system whereby the source material is provided as a liquid or as a solid and melted to liquid form. The systems and apparatus of the present disclosure allow for rapid introduction and removal of liquids from the plasma chamber, thus improving throughput, reducing cross-contamination, and reducing waste of source material.

[0083] According to another exemplary embodiment, a method 500 for supplying liquid metal to an ion source for forming an ion beam for ion implantation into a workpiece is provided in FIG. 6. Although the exemplary method is illustrated and described herein as a series of steps or events, it will be appreciated that the disclosure is not limited by the illustrated order of such steps or events, as some steps may occur in different orders and / or simultaneously with other steps other than those illustrated and described herein, in accordance with the present disclosure. In addition, not all of the illustrated steps may be required to practice a method in accordance with the present disclosure. Furthermore, it will be appreciated that the method may be practiced in association with other systems not illustrated, as well as the systems illustrated and described herein.

[0084] It should be noted that the controller 138 of Figure 1 may be configured to execute the method 500 of Figure 6, whereby control of the various components discussed above may be accomplished in the manner described herein. As shown in Figure 6, the illustrated method 500 begins at step 502, where a material, such as a metal in elemental form, is provided to an ion source in solid form. The metal may be a powder or other solid form. The metal is provided, for example, to a cup of a reservoir device disposed within the arc chamber, as described above in some examples.

[0085] In step 504, a metal is heated to a liquid state, and in step 506, the liquefied metal is provided to an interior region of the arc chamber. Steps 504 and 506 can be performed sequentially or simultaneously in various orders. In one example, the metal is heated to a liquid state outside the arc chamber in step 504, and then provided to the interior region of the arc chamber in step 506. In step 508, the liquid metal is vaporized to form a plasma.

[0086] Although the present disclosure has been shown and described with respect to a particular embodiment or embodiments, it should be noted that the above-mentioned embodiments merely serve as examples of some embodiments of the present disclosure, and the application of the present disclosure is not limited to these embodiments. In particular, with respect to the various functions performed by the above-mentioned components (assemblies, devices, circuits, etc.), the terms used to describe such components (including references to "method") are intended to correspond to any components that perform the specified function of the described components (i.e., are functionally equivalent), even if they are not structurally equivalent to the disclosed structures that perform the function in the exemplary embodiments of the present disclosure illustrated herein, unless otherwise indicated. In addition, although a particular feature of the present disclosure may be described only with respect to one of several embodiments, such feature can be combined with one or more other features of other embodiments, as may be desired and advantageous for any given or particular application. Thus, the present disclosure is not intended to be limited to the above-mentioned embodiments, but only by the appended claims and their equivalents.

Claims

1. 1. An ion source for an ion implantation system, comprising: The ion source comprises: an arc chamber defining an arc chamber volume; a reservoir operatively connected to the arc chamber and defining a reservoir volume; a conduit fluidly connecting the reservoir volume to the arc chamber volume; a fluid control device operatively connected to the reservoir; The reservoir volume is configured to contain a liquid therein; the conduit having a first opening and a second opening; the first opening is operably connected to the reservoir; the second opening is located above the first opening and is open to the arc chamber volume; the liquid control device is configured to control a first volume of the liquid defined within the reservoir volume; The first volume of the liquid within the reservoir volume further defines a predetermined supply of the liquid to the arc chamber volume.

2. The liquid control device includes: a gas source fluidly connected to the reservoir and configured to selectively supply gas to the reservoir; a gas pressure control device configured to control the pressure of the gas in the reservoir; The ion source of claim 1 , wherein a pressure of the gas defines the first volume of the liquid within the reservoir volume.

3. The liquid control device includes: a pressurized gas source fluidly connected to the reservoir and configured to selectively supply gas to the reservoir; a gas exhaust orifice defining a predetermined fluid conductance between the reservoir volume and an external environment; a gas flow control device configured to control a flow of the gas to the reservoir; The ion source of claim 1 , wherein the flow rate and a predetermined fluid conductance define the first volume of the liquid within the reservoir volume.

4. 10. The ion source of claim 1, wherein the liquid control device comprises one or more of a bladder, a syringe, or a mechanical device configured to mechanically control the size of the first volume.

5. the fluid control device comprising an elevator mechanism operatively connected to the reservoir; 2. The ion source of claim 1, wherein the elevator mechanism is configured to selectively vary a vertical position of the reservoir relative to the arc chamber to define the predetermined supply of the liquid to the arc chamber volume by gravity.

6. a cup disposed within the arc chamber; the cup defines a cup volume; The ion source of claim 1 , wherein the second opening of the conduit is defined in a bottom surface of the cup.

7. the cup includes a stem extending from the bottom surface of the cup and penetrating a wall of the arc chamber; the conduit is defined within the stem; The ion source of claim 6 , wherein the reservoir is disposed below the cup.

8. 8. The ion source of claim 7, wherein the liquid control device controls a second volume of the liquid in the cup volume through the control of the first volume of the liquid in the reservoir volume.

9. the liquid control device comprises a source of pressurized gas fluidly connected to the reservoir; the pressurized gas source is configured to selectively supply gas to the reservoir to maintain a predetermined pressure within the reservoir; 9. The ion source of claim 8, wherein the predetermined pressure defines the first volume of the liquid within the reservoir volume and the second volume of the liquid within the cup volume.

10. The liquid control device includes: a gas exhaust orifice defining a predetermined fluid conductance between the reservoir volume and an external environment; a gas flow control device configured to control a flow of the gas to the reservoir; The ion source of claim 9 , wherein the flow rate and a predetermined fluid conductance define the first volume of the liquid within the reservoir volume.

11. a repeller device operably connected to a bottom of the arc chamber; The ion source of claim 9 , wherein the cup is defined within the repeller apparatus.

12. a heat source in thermal communication with the reservoir; The ion source of claim 1 , wherein the heat source is configured to selectively heat the reservoir.

13. The ion source of claim 12 , wherein the heat source comprises one or more of an electric cartridge heater and a heat lamp operably connected to the reservoir.

14. the arc chamber includes a sidewall defining the heat source; The ion source of claim 12 , wherein the sidewall of the arc chamber is configured to transfer heat associated with a plasma within the arc chamber volume to the reservoir.

15. the reservoir is selectively connected to the arc chamber; the reservoir volume is configured to selectively receive a solid source species for placement therein; The ion source of claim 12 , wherein the heat source is configured to melt the solid source species to define the liquid.

16. 1. An ion source for an ion implantation system, comprising: The ion source comprises: an arc chamber defining an arc chamber volume; a cup disposed within the arc chamber, the cup defining a cup volume and including a stem extending from a bottom surface of the cup and penetrating a wall of the arc chamber; a reservoir operatively connected to the arc chamber and defining a reservoir volume; a conduit defined within the stem; and a heat source in thermal communication with the reservoir; a fluid control device operatively connected to the reservoir; The reservoir volume is configured to contain a liquid therein; the conduit fluidly connects the reservoir volume to the arc chamber volume; the heat source is configured to selectively heat the reservoir; the liquid control device is configured to control a first volume of the liquid defined within the reservoir volume; The first volume of the liquid within the reservoir volume further defines a second volume of the liquid within the cup volume.

17. The liquid control device includes: a pressurized gas source fluidly connected to the reservoir and configured to selectively supply gas to the reservoir; a gas exhaust orifice defining a predetermined fluid conductance between the reservoir volume and an external environment; a gas flow control device configured to control a flow of the gas to the reservoir; 17. The ion source of claim 16, wherein the flow rate and a predetermined fluid conductance define the first volume of the liquid within the reservoir volume.

18. the reservoir is selectively connected to a bottom of the arc chamber; the reservoir volume configured to selectively receive a solid source species for placement therein; The ion source of claim 16 , wherein the heat source is configured to melt the solid source species to define the liquid.

19. 1. An ion source for an ion implantation system, comprising: The ion source comprises: an arc chamber defining an arc chamber volume; a reservoir selectively operatively connected to a bottom of the arc chamber and defining a reservoir volume; a repeller device operatively connected to the arc chamber; a heat source in thermal communication with the reservoir; a fluid control device operatively connected to the reservoir; the reservoir is configured to selectively receive a solid source species for placement within the reservoir volume; the repeller apparatus comprising a cup defining a cup volume; the repeller device includes a stem extending from a bottom surface of the cup and penetrating a bottom of the arc chamber; A conduit is defined within the stem; the conduit fluidly connects the reservoir volume to the arc chamber volume; the heat source is configured to selectively heat the reservoir to melt the solid source species to define a liquid; the liquid control device is configured to control a first volume of the liquid defined within the reservoir volume; The first volume of the liquid within the reservoir volume further defines a second volume of the liquid within the cup volume.

20. The liquid control device includes: a pressurized gas source fluidly connected to the reservoir and configured to selectively supply gas to the reservoir; a gas exhaust orifice defining a predetermined fluid conductance between the reservoir volume and an external environment; a gas flow control device configured to control a flow of the gas to the reservoir; 20. The ion source of claim 19, wherein the flow rate and a predetermined fluid conductance define the first volume of the liquid within the reservoir volume.

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