Fluoride ion implantation method and system

Abstract

The present invention describes a method and system for fluorine ion implantation, wherein a fluorine compound capable of forming a plurality of fluorine ion species is introduced into an ion implanter at a predetermined flow rate. The fluorine ion species are generated at a predetermined arc power and source magnetic field to provide an optimized beam current for a desired fluorine ion species. The desired fluorine ion species (e.g., ion species having a plurality of fluorine atoms) are implanted into a substrate under selected operating conditions.

Description

Technical Field

[0001] The present invention relates to a fluoride ion implantation method and system. Background Art

[0002] Fluorine implantation is used in advanced semiconductor device fabrication for defect engineering, shallow junction formation, and material modification. A common setup for fluorine implantation includes feeding a fluoride dopant source gas into an ion source to provide fluorine (F) as one of the decomposition byproducts.

[0003] However, conventional fluorine implantation processes are generally limited with respect to the type of fluorine ions implanted and the specificity of the fluorine ion implantation, such as with respect to the fluorine ion implantation depth. In addition, ionic species generated upon decomposition of fluorine-containing compounds may also be undesirably co-implanted with fluorine.

[0004] Furthermore, the use of fluorine-containing feed gases creates a halogen cycle that can adversely affect ion source performance, source lifetime, implant tool productivity, and cost of tool ownership.Given the wide range of potential applications for fluoride ion beams, various challenges continue to exist in the art for improving fluoride ion beam performance. Summary of the invention

[0005] The present invention relates to methods and systems for implanting one or more desired fluoride ion species into a substrate in an ion implantation process. The methods and systems allow multiple fluoride ion species to be generated from fluorine-containing compounds. Using predetermined flow rate, arc power, and source magnetic field conditions, an optimized beam current can be generated for the desired fluoride ion species, which in turn can be targeted for implantation into the substrate. Thus, the current method achieves greater control over the implanted fluoride species and how they are implanted into the substrate, which in turn provides a substrate with a higher level of chemical modification, such as a microelectronic device with improved electronic properties.

[0006] According to one embodiment, a fluorine ion implantation method comprises the steps of flowing a composition comprising a fluorine compound into an ion implanter at a predetermined flow rate, the fluorine compound comprising one non-fluorine atom and one or more fluorine atoms, the implanted ions being configured for fluorine ion implantation into a substrate. The method further comprises operating the ion implanter to produce fluorine ion species from the fluorine compound at a predetermined arc power and magnetic field, wherein the fluorine ion species comprises a desired fluorine ion species for substrate implantation. During operation, the flow rate, arc power, and magnetic field are selected to provide an optimized beam current for the desired fluorine ion species. Thus, the desired fluorine ion species is implanted into the substrate under the selected operating conditions.

[0007] In some embodiments, the method may be useful for implanting F + The ion implantation system is operated at a predetermined flow rate, arc power, and source magnetic field to provide fluorine ion species F +Under the selected operating conditions, the fluoride ion species F + In some embodiments, the fluoride ion species F + Fluorine-containing compounds such as SiF4, BF3, GeF4, and CF4 may be used to obtain the fluorine-containing compounds, but are not limited to these compounds. In some cases, when compared to fluoride species F generated from SiF4, BF3, or GeF4 under the same or similar conditions, the fluoride species F + When fluoride ion species F is generated from CF4 under certain conditions + Higher beam currents were observed when CF4 was added to the mixture. Higher beam currents appear to be obtainable at lower gas flow rates. Furthermore, the addition of a hydrogen (H2) co-gas to the CF4 gas stream does not appear to significantly affect the beam current for mixtures or co-flow gas streams containing up to 33% hydrogen.

[0008] Other embodiments relate to methods for implanting ionic species having multiple fluorine atoms, referred to herein as "molecular implantation" or "cluster implantation," by obtaining an optimal beam current for such ionic species. Cluster implantation can be accomplished with fluorinated compounds including atoms such as boron, silicon, germanium, antimony, arsenic, xenon, molybdenum, carbon, selenium, sulfur, and nitrogen. An exemplary fluorine compound is SiF4, which produces a fluorine-containing compound. + 、SiF + 、SiF2 + 、SiF3 + and SiF4 + Another exemplary fluorine compound is BF3, which produces fluoride ions including F + , BF + 、BF2 + and BF3 + An exemplary fluorine compound is GeF4, which produces fluoride ions including F + , GeF + 、GeF2 + 、GeF3 + and GeF4 + Another exemplary fluorine-containing compound is CF4, which produces fluoride ions including F + 、F2 + CF + CF2 + CF3 + and CF4 + of fluoride ion substances.

[0009] For cluster implantation, higher beam currents can be achieved using the method of the present invention. +Ionic fluoride species (molecules or clusters) can be more easily ionized, resulting in reduced arc power and stress on the ion source and implantation tool. In addition, the desired implantation depth can be achieved at higher energies, which can be easily achieved and with less stress on the implantation tool. Molecular or cluster implantation, which can be performed at lower beam currents using the method of the present invention, can also extend source life. In addition, the method of the present invention can optionally be used to implant atoms or chemicals other than fluorine, thereby allowing an overall reduction in the number of implantation steps.

[0010] Embodiments of the present invention also include flowing a hydrogen-containing gas other than a fluorine compound into the ion implanter. Embodiments of the present invention also include flowing an oxygen-containing gas other than a fluorine compound into the ion implanter. Even further, embodiments of the present invention may also include flowing an inert gas into the ion implanter. The method of the present invention includes flowing one or more of these gases independently of the fluorine compound or mixed with each other. In some embodiments, hydrogen (H2) and the fluorine-containing gas may be flowed independently (co-flow) or mixed. The use of one or more of these gases other than a fluorine compound may improve implant beam current, source lifetime performance, or both. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic illustration of an ion implantation system including an arc chamber having a gas feed line for feeding a dopant source gas into the arc chamber for ionization thereof in the chamber.

[0012] Figure 2 for Figure 1 Cross-section of an ion implantation system schematically illustrating the generation of a plasma in an arc chamber of such a system.

[0013] Figure 3 is a cross-sectional perspective view of an ion source assembly including an ion source device and a heat sink device for thermal management of the ion source device.

[0014] Figure 4 is a schematic illustration of an ion implantation processing system including a storage and dispensing vessel containing a gas supplied for ion implantation doping of a substrate in the illustrated ion implantation chamber.

[0015] Figure 5 Beam spectrum data is shown using SiF4 at different flow rates in the presence of a tungsten arc chamber with a tungsten liner.

[0016] Figure 6 F from experiments using GeF4 gas in the presence of a tungsten backing versus a graphite backing is shown. + Beam current data.

[0017] Figure 7 Demonstration from using GeF4 gas and less W when using graphite liner + and WF x + beam experiments to ionize matter.

[0018] Figure 8 Shows F from experiments using a mixture of BF3 and H2 gases + Beam current data.

[0019] Fig. 9 The results show that the W decreases when H2 is mixed with BF3 gas using BF3 / H2 mixture. + and WF x + beam experiments to ionize matter.

[0020] Fig.10 Comparison of the F generated at different flow rates for different fluorine-containing gases + Beam current.

[0021] Fig.11 The beam spectrum data of CF4 gas at different flow rates in the presence of a tungsten arc chamber with a tungsten liner are shown.

[0022] Fig.12 Shows F plotted against the percentage of hydrogen in a gas mixture containing CF4 and H2 + Beam current data.

[0023] Fig.13 Shows HF plotted against the percentage of hydrogen in a gas mixture containing CF4 and H2 + and W + Beam current data.

[0024] Fig.14 Show that when CF4 gas undergoes ionization in an ion implantation system, F + Plot of beam current evolution over time for CF4 gas, the ion implantation system comprising a tungsten arc chamber with a tungsten liner.

[0025] Fig.15 The beam current trends are shown as a function of time for F+, W+, C+, and CF+ beam currents generated from CF4 gas in the presence of a tungsten arc chamber with a tungsten liner. DETAILED DESCRIPTION

[0026] The present invention relates to fluoride ion implantation and, in various aspects, to methods and systems using fluorine compounds that produce a plurality of fluoride ion species, and the systems are operated at a predetermined flow rate of the fluorine compound, a predetermined arc power, and a predetermined source magnetic field. The operating conditions provide an optimized beam current for a desired fluoride ion species, which in turn can be targeted for implantation into a substrate. In some cases, the desired fluoride ion species can be a monatomic F. + In other cases, the desired fluorine species may contain polyatomic or molecular or clustered fluorine ion species, such as F2 used in "cluster implantation". + or SiF3+.

[0027] In the process of the present invention, one or more fluorine compounds are used that are capable of being ionized to form fluoride-containing ion species.

[0028] One type of fluorine compound consists of a compound having the formula Q x F y The compound is represented by x F y In the formula Q, Q is an element capable of forming a bond with fluorine (F), and both x and y are integers of 1 or greater. In an embodiment, x is an integer in the range of 1 to 3, and y is an integer in the range of 1 to 8; in an embodiment, x is 1 or 2, and y is an integer in the range of 1 to 6. For some formulas Q x F y For some compounds of formula Q x F y For compounds of formula Q, y is greater than x. For example, y is twice x, y is three times x, y is four times x, y is five times x, or y is six times x. x F y The compound wherein y is 1+x, y is 2+x, y is 3+x, y is 4+x or y is 5+x.

[0029] When ionized using the conditions described herein, a x F y The compounds may produce compounds including those of formula F + , Formula Q u F v + Japanese style F2 + The fluorine ion substance of the compound. Substances with multiple fluorine atoms are called molecules or cluster substances. Both u and v are integers and can be used for formula Q x F y , wherein x is an integer greater than or equal to u, and u is an integer greater than or equal to 1; and wherein y is an integer greater than or equal to v, and v is an integer greater than or equal to 1. Therefore, for the formula Q u F v+ ionic species, and both u and v are integers of 1 or greater. In an embodiment, u is an integer in the range of 1 to 3, and v is an integer in the range of 1 to 8; in an embodiment, u is 1 or 2, and v is an integer in the range of 1 to 6. For some formula Q u F v + For ionic species, u is equal to v, for example, both u and v are 1. u F v + For ionic substances, v is greater than u. For example, v is twice u, v is three times u, v is four times u, v is five times u, or v is six times u. For some formula Q u F v + For ionic substances, v is 1+u, v is 2+u, v is 3+u, v is 4+u or v is 5+u.

[0030] Examples of silicon- and fluorine-containing compounds include those having the formula SiF4 and the formula Si2F6, which can be ionized to produce fluoride ion species, including ion species selected from the group consisting of: F + 、F2 + 、SiF + 、SiF2 + 、SiF3 + 、SiF4 + 、Si2F + 、Si2F2 + 、Si2F3 + 、Si2F4 + 、Si2F5 + and Si2F6 + In a preferred aspect, SiF4 is ionized to produce two or more selected from F + 、SiF + 、SiF2 + 、SiF3 + and SiF4 + The substance that makes up the group.

[0031] Examples of boron-containing and fluorine-containing compounds include those of formula BF3 and formula B2F4, which can be ionized to produce fluoride ion species, including ion species selected from the group consisting of: F + 、F2 + , BF + 、BF2 + 、BF3 + 、B2F + 、B2F2 + 、B2F3 + and B2F4+ In a preferred aspect, BF3 is ionized to produce two or more selected from F + , BF + 、BF2 + and BF3 + The substance that makes up the group.

[0032] Examples of germanium- and fluorine-containing compounds include those of the formula GeF4 and Ge2F6, which can be ionized to produce fluoride ion species, including ion species selected from the group consisting of: F + 、F2 + , GeF + 、GeF2 + 、GeF3 + 、GeF4 + ,Ge2F + 、Ge2F2 + 、Ge2F3 + 、Ge2F4 + 、Ge2F5 + and Ge2F6 + In a preferred aspect, GeF4 is ionized to produce two or more selected from F + , GeF + 、GeF2 + 、GeF3 + and GeF4 + The substance that makes up the group.

[0033] Examples of phosphorus- and fluorine-containing compounds include those of formula PF3 and formula PF5, which can be ionized to produce fluoride ion species, including ion species selected from the group consisting of: F + 、F2 + and PF + PF2 + PF3 + PF4 + and PF5 + .

[0034] Examples of arsenic- and fluorine-containing compounds include those of the formula AsF3 and AsF5, which can be ionized to produce fluoride species, including those selected from the group consisting of F + 、F2 + and AsF + 、AsF2 + 、AsF3 + 、AsF4 + and AsF5 + A group of ionic substances.

[0035] Examples of antimony-containing and fluorine-containing compounds include compounds of the formula SbF5, which can be ionized to produce fluoride ion species, including those selected from the group consisting of F + 、F2 + and SbF + 、SbF2 + 、SbF3 + 、SbF4 + and SbF5 + A group of ionic substances.

[0036] Examples of tungsten- and fluorine-containing compounds include those of formula WF6, which can be ionized to produce fluoride ion species, including those selected from the group consisting of F + 、F2 + and WF + 、WF2 + 、WF3 + 、WF4 + 、WF5 + and WF6 + A group of ionic substances.

[0037] Examples of nitrogen-containing and fluorine-containing compounds include those of formula NF3 and formula N2F4, and the fluoride ion species include two or more species selected from the group consisting of: F + 、F2 + NF + NF2 + NF3 + 、N2F + 、N2F2 + 、N2F3 + 、N2F4 + 、N2F5 + and N2F6 + .

[0038] Examples of carbon-containing and fluorine-containing compounds include those of the formula CF4 and C2F6, and the fluoride ion species include two or more species selected from the group consisting of: F + 、F2 + CF + CF2 + CF3 + CF4 + 、C2F + 、C2F2 + 、C2F3 + 、C2F4 + 、C2F5 + and C2F6 + .

[0039] Other types of fluorine-containing compounds that can generate fluoride ion species include those of formula Qx R z F y A compound wherein Q and R are elements capable of forming a bond with fluorine (F), and x, z, and y are integers of 1 or greater. In an embodiment, Q is selected from the group consisting of B, Si, Ge, P, As, C, and N; and R is selected from H and O. In an embodiment, x is an integer in the range of 1 to 3, and preferably 1 or 2; z is an integer in the range of 1 to 4, and preferably 1, 2, or 3; and y is an integer in the range of 1 to 8, preferably 1 to 6.

[0040] After ionization using the conditions described herein, a compound having the formula Q x R z F y Compounds that can generate fluoride ion species include those of formula Q u R w F v + Japanese style F + 、Formula F2 + u, w and v are all integers and can be related to the formula Q x R z F y , wherein x is an integer greater than or equal to u, and u is an integer greater than or equal to 1; and wherein y is an integer greater than or equal to v, and v is an integer greater than or equal to 1, and wherein z is an integer greater than or equal to w, and w is an integer greater than or equal to 1. Therefore, for the formula Q u R w F v + ionic species, u, w and v are all integers of 1 or greater. Preferably, u is an integer in the range of 1 to 3, and preferably 1 or 2; w is an integer in the range of 1 to 4, and preferably 1, 2 or 3; and v is an integer in the range of 1 to 8, preferably 1 to 6.

[0041] With formula Q x R z F y Examples of compounds include, but are not limited to, those such as BHF, BHF2, SiHF3, SiH2F2, SiH3F, Si2H3F3, Si2H5F, Si2HF5, GeHF3, GeH2F2, GeH3F, PHF2, PH2F, PH3F2, P2HF, AsHF2, AsH2F, AsH3F2, C n H x F 2n+2-x , C n H x F 2n-x , C n Hx F 2n-2-x , COF2, NHF2, NH2F, NHF and N2H3F, wherein n is an integer in the range of 1 to 3, and x is 0, 1 or 2.

[0042] Other types of fluorine-containing compounds that can generate fluoride ion species include those of formula F y The fluoride ion substance includes a compound of formula F v + A compound wherein y is an integer greater than or equal to v, and v is an integer greater than or equal to 1.

[0043] The method of the present disclosure may also include using two or more of the formula Q x F y , Formula Q x R z F y Japanese style F y If two or more different fluorine-containing compounds are used, these compounds can be flowed into the implant chamber independently, or can be flowed into the chamber as a mixture.

[0044] In the methods of the present invention, one or more fluorine-containing compounds are flowed into the implant chamber to produce fluoride ion species. The fluoride ion species may include species with the maximum number of fluorine atoms. In the methods of the present invention, the flow rate, arc power, and source magnetic field are selected so that the species with the desired number of fluorine atoms is optimized for maximum beam current. In other methods, the flow rate, arc power, and source magnetic field are selected so that the fluoride ion species F + Optimized for maximum beam current.

[0045] Operation of the system for fluorine ion implantation may be described in terms of arc power and arc voltage. In some practice modes, the system is operated to provide an arc power in the range of about 5 W to about 2500 W, or in some practice modes, an arc power in the range of about 90 W to about 1500 W. To achieve an arc power in one of these ranges, the system may be operated to produce an arc voltage in the range of about 30 V to about 150 V, or more specifically, in the range of about 60 V to about 125 V.

[0046] The operation of the system for fluorine ion implantation may also be described in terms of the flow rate of the fluorine-containing compound flowing into the ion implantation chamber. In some embodiments, the fluorine-containing compound flows into the chamber at a rate of no more than 10 sccm, and in embodiments, the fluorine-containing compound flows at a rate in a range of 0.1 sccm to 6 sccm. In other embodiments, the fluorine-containing compound flows to the system at a flow rate in a range of 0.2 sccm to 4 sccm, and more particularly in a range of 0.2 sccm to 2 sccm.

[0047] In some specific practice modes, the fluorine compound is BF3, and the fluoride ion species includes a fluoride selected from the group consisting of F + , F2+, BF + 、BF2 + and BF3 + A group of two or more substances consisting of; an arc power in the range of 50W to 2500W generated at an arc voltage in the range of 30V to 150V, and a flow rate in the range of 1.25sccm to 1.75sccm.

[0048] In some specific practice modes, the fluorine compound is SiF4, and the fluorine ion species includes a fluorine ion selected from the group consisting of F + 、F2+、SiF + 、SiF2 + 、SiF3 + and SiF4 + A group of two or more substances consisting of; an arc power in the range of 50W to 2500W generated at an arc voltage in the range of 75V to 125V, and a flow rate in the range of 1.0sccm to 1.5sccm.

[0049] In some specific practice modes, the fluorine compound is GeF4, and the fluorine ion species includes a fluorine ion selected from the group consisting of F + 、F2+、GeF + 、GeF2 + 、GeF3 + and GeF4 + A group of two or more substances consisting of; an arc power in the range of 50W to 2500W generated at an arc voltage in the range of 30V to 150V, and a flow rate in the range of 0.2sccm to 0.8sccm.

[0050] In some specific practice modes, the fluorine compound is CF4 and the fluoride ion species include F+, F2 + CF + CF2 + and CF3 + At least one of; an arc power in the range of 50W to 2500W generated by an arc voltage in the range of 30V to 150V, and a flow rate in the range of 0.2sccm to 1.5sccm and more specifically in the range of 0.3sccm to 1.0sccm.

[0051] Optionally, the method of the present disclosure may include flowing a (non-fluorinated) hydrogen-containing or hydride-containing compound other than a fluorine compound to the ion implanter. Examples of such compounds include, but are not limited to, compounds such as H2, B2H6, SiH4, Si2H6, GeH4, Ge2H6, PH3, AsH3, CH4, C2H6, C x H y (where x and y are equal to or greater than 1), NH3 and N2H4. In an exemplary mode of practice, a hydrogen-containing or hydride-containing compound flows into the arc chamber at a rate of 0.05 sccm to 10 sccm.

[0052] Optionally, the method of the present disclosure may include flowing a (non-fluorinated) oxygen-containing compound other than a fluorine compound to the ion implanter. Examples of such compounds include, but are not limited to, compounds such as O2, O3, H2O, H2O2, CO, CO2, NO, NO2, N2O, N4O, N2O3, N2O4, N2O5, and N2O6.

[0053] Optionally, the methods of the present disclosure may include flowing an inert gas to the ion implanter. Examples of inert gases include nitrogen, helium, neon, argon, krypton, and xenon.

[0054] In a practice mode, one of a hydrogen- or hydride-containing gas, an oxygen-containing gas, or an inert gas is flowed to the implanter along with the fluorine-containing compound; in other practice modes, two of the gases are flowed; and in still other practice modes, all three gases are flowed to the implanter along with the fluorine-containing compound.

[0055] If more than one gas is flowed to the chamber, the gases may flow separately. Alternatively, the gases may flow mixed. For example, any two or more of a fluorine-containing gas, a hydrogen-containing gas, an oxygen-containing gas, and / or an inert gas may be premixed in the cylinder package. In yet other embodiments, two or more gases are mixed and then another gas is flowed separately to the chamber. In one embodiment, hydrogen is flowed or premixed with the fluorine-containing gas in the same direction.

[0056] The method of the present invention can be performed using an ion source device for ion implantation. Any type of ion implantation system can be used for the fluorine implantation method as described herein. The system includes an arc chamber formed of one or more tungsten-containing materials or non-tungsten-containing materials. In some embodiments, the combination of carbon-containing and fluorine-containing compounds (such as CF4 or C2F6) with a tungsten arc chamber and / or a tungsten-containing liner for fluorine ion implantation can improve F+ implantation performance (including beam current and source life) and reduce the amount of tungsten fluoride formed during the implantation process.

[0057] Exemplary non-tungsten-containing materials may include, but are not limited to, graphite-containing materials, carbide-containing materials, fluoride-containing materials, nitride-containing materials, oxide-containing materials, or ceramics. Exemplary systems using non-tungsten-containing materials are described in U.S. Provisional Application No. 62 / 780,222, which is incorporated herein by reference in its entirety for all purposes. The presence of these non-tungsten materials in the chamber can replace tungsten, which in some embodiments can improve F+ implant performance (including beam current and source lifetime). Specifically, these materials can reduce the amount of tungsten fluoride formed during the implant process.

[0058] The ion source device may include a structural component disposed in the ion source chamber, such as a liner or other structural component of the ion source chamber. The liner may be flat, such as a planar structural piece having two opposing main surfaces and a thickness therebetween. The liner may be rectangular, curved (e.g., circular), angular, or other shapes. The liner may be removable, meaning that the liner may be inserted into the interior space of the ion source chamber and removed from the interior space. In other cases, the liner may be permanent and may not be removed from the chamber.

[0059] Now refer to the diagram, Figure 1 1 is a schematic illustration of an ion implantation system 10, which includes an arc chamber 12 having a gas feed line 14 for feeding a fluorine-containing gas into the arc chamber for ionization thereof in the chamber. The arc chamber 12 thus provides an ion source chamber. In some embodiments, the arc chamber may include a tungsten arc chamber and a tungsten liner. In other embodiments, the arc chamber may include a tungsten arc chamber and a non-tungsten-containing material liner. In other embodiments, both the arc chamber and the liner may include a non-tungsten-containing material. Suitable non-tungsten-containing materials may include, but are not limited to, graphite-containing materials, carbide-containing materials, fluoride-containing materials, nitride-containing materials, oxide-containing materials, or ceramics to reduce the amount of tungsten fluoride formed during the implantation process and / or improve the fluorine implantation beam current.

[0060] Figure 2 for Figure 1 A cross section of an ion implantation system 10 schematically illustrating the generation of a plasma 16 in an arc chamber 12 of such a system. A fluorine-containing gas is caused to flow in the direction indicated by arrow A into a fluorine-containing gas feed line 14 having monitoring thermocouples TC1 and TC2 secured thereto in monitoring relationship to determine the quality of the thermal state of the feed line and the gas entering the arc chamber, as may be desired for use in conjunction with a thermal management system for the ion implantation system.

[0061] Figure 3is a cross-sectional perspective view of an ion source assembly including an ion source assembly 70 and an optional heat sink assembly 50 for thermal management of the system. This cross-sectional view shows a fluorine-containing gas feed line 72 connected to a gas flow channel 84 in a gas feed plug and to a gas flow channel 86 in a gas sleeve associated with the ion source.

[0062] Figure 3 The ion source device shown in includes a substrate 80. The substrate 80 may be coated or modified with a tungsten-containing material, or may be coated or modified with a graphite-containing material, a carbide-containing material, a fluoride-containing material, a nitride-containing material, an oxide-containing material, or a ceramic. The substrate 80 may include an opening 82 therein.

[0063] Figure 4 is a schematic illustration of an ion implantation process system 300 including a storage and dispensing vessel 302 containing a reactant gas supplied for in situ reaction with a fluorine-containing gas in an ion source chamber to produce fluorine ion species for ion implantation of a substrate 328 in the illustrated ion implantation chamber 301.

[0064] The storage and dispensing vessel 302 includes a vessel wall 306 that encloses an interior volume containing fluorine gas.

[0065] The container may be a conventional type of cylinder in which the interior volume is configured to contain only the gas, or alternatively, the container may contain an adsorbent material having an adsorptive affinity for the reactant gas and in which the co-reactant source gas is desorbable under dispensing conditions to be exhausted from the container.

[0066] The storage and dispensing vessel 302 includes a valve head 308 coupled in gas flow communication with a discharge line 312. A pressure sensor 310 is disposed in the line 312 along with a mass flow controller 314. Other monitoring and sensing components may be coupled to the line and interface with control components such as actuators, feedback systems and computer control systems, cycle timers, etc.

[0067] The ion implantation chamber 301 contains an ionizer 316 that receives a dispensed fluorine-containing gas from a line 312, which reacts with a dopant source reactant disposed in or associated with the ionizer chamber to produce fluoride ion species that, under ionization conditions in the ionizer chamber, produce an ion beam 305. The ion beam 305 passes through a mass analyzer unit 322, which selects desired ions and rejects non-selected ions.

[0068] The selected ions pass through acceleration electrode array 324 and then through deflection electrodes 326. The resulting focused ion beam impinges on substrate 328, which is disposed on a rotatable holder 330 mounted on an opening shaft 332, to form a doped (fluorine-doped) substrate as an ion implantation product.

[0069] Corresponding portions of ion implantation chamber 301 are exhausted via lines 318, 340, and 344 by means of pumps 320, 342, and 346, respectively.

[0070] Example 1

[0071] According to the present invention, fluorine-containing gas SiF4 is flowed into the ionization chamber at various flow rates (0.5, 1.5 and 2.5 sccm) under predetermined arc power and magnetic field. The beam current of the ion species is measured at different flow rates. Figure 5 As shown in + Materials are adjusted to optimize conditions and beams to obtain high SiF3 + Beam current.

[0072] Example 2

[0073] Fluorine-containing gas GeF4 was flowed into an ionization chamber with a tungsten liner and an ionization chamber with a graphite liner. The system was operated at an arc voltage of 110V and a source beam of 20mA. The F+ ion beam current was measured at various gas GeF4 flow rates. At each flow rate tested, the system with the graphite liner provided higher F+ ion beam current than the system with the tungsten liner. + The results are shown in Figure 6 middle.

[0074] Example 3

[0075] The beam spectra of various ionized species produced by the process described in Example 2 were measured. The results show that with the graphite liner, significantly less W is visible from the GeF4 beam spectrum. + and WF x + See also Figure 7 .

[0076] Example 4

[0077] Fluorine-containing gas BF3 was flowed into the ionization chamber alone and in the presence of hydrogen (H2). The flow rate of BF3 was 1.5 sccm, and the system was operated at an arc voltage of 110 V and a source beam of 20 mA. Figure 8 Shows F under increasing concentrations of H2 + The beam current was shown to be only slightly affected when H2 was increased to 50%. However, when the BF3 beam spectrum of the ionized species was analyzed, it showed a significant reduction in the W+ and WFx+ beams when H2 was mixed with BF3. Fig. 9 .

[0078] Example 5

[0079] The F+ beam current produced from different fluorine gases (BF3, SiF4, GeF4, CF4) under the same operating conditions was evaluated. The gases were flowed independently into an ionization chamber with a tungsten chamber (with a tungsten liner). The system was operated at an arc voltage of 110V and an arc voltage of 90V and a source beam of 20mA. For each of the gases, the F+ ion beam current was measured at various flow rates. At lower flow rates, CF4 produced significantly higher F+ than BF3, SiF4, and GeF4. + The results are shown in Fig.10 middle.

[0080] Example 6

[0081] Fig.11 The F generated from CF4 at different gas flow rates under the conditions described in Example 5 is shown. + As can be seen, a higher F + When the gas flow rate increases from 0.42 sccm to 1 sccm, F + and W ++ The beam current decreases and W + , C + and CF + The beam current increases.

[0082] Example 7

[0083] A gas mixture containing CF4 and H2 was flowed into an ion implantation system including a tungsten arc chamber (with a tungsten liner) at a fixed flow rate of 0.5 seem, an arc voltage of 110 V, and a source beam of 20 mA. Fig.12 Shows the variation of F with the percentage of hydrogen in the mixture + For mixtures containing up to 33% hydrogen, a decrease in the amount of F + The beam current had no significant effect. Fig.13 Shows HF plotted against the amount of hydrogen in the gas mixture + and W + As expected, W + The beam current is significantly reduced and the HF + The beam current increases.

[0084] Example 8

[0085] The F generated by the ionization of CF4 in a tungsten arc chamber with a tungsten liner was studied at a fixed flow rate of 0.5 sccm, an arc voltage of 110 V and a source beam of 20 mA. + Beam current stability. Fig.14 Display F+ The beam current increased with time and became stable after 2-3 hours. Fig.15 Compare Fig.14 The F+ and C + CF + , W + The beam current. C + The beam current decreases during the first half period and begins to increase during the second half period. + The initial decrease in C can be attributed to the removal of carbon residues from the previous CO bundle. + The late increasing trend of beam current may be related to carbon deposition from CF4 itself. + The beam current has a + The contact increase trend of beam current alignment.

Claims

1. A fluorine ion implantation method, comprising: Flowing a composition comprising a fluorine compound into an ion implanter at a predetermined flow rate, the fluorine compound comprising one non-fluorine atom and more than one fluorine atom, the implanted ions being configured to implant fluorine ions into a substrate, wherein the fluorine compound comprises a compound of formula Q x R z F y , wherein Q and R are elements capable of forming a bond with fluorine F, and x, z and y are integers of 1 or greater; operating the ion implanter to produce fluoride ion species from the fluorine compound at a predetermined arc power and magnetic field, wherein the fluoride ion species includes a clustered species having a plurality of fluorine atoms; wherein the flow rate, arc power, and magnetic field are selected to provide an optimized beam current for the fluoride ion species; The fluoride ion material comprises at least one of the following: F2 + 、SiF2 + 、SiF3 + 、SiF4 + 、Si2F + 、Si2F2 + 、Si2F3 + 、Si2F4 + 、Si2F5 + 、Si2F6 + 、BF2 + 、BF3 + 、B2F + 、B2F2 + 、B2F3 + 、B2F4 + PF2 + PF3 + PF4 + PF5 + 、AsF2 + 、AsF3 + 、AsF4 + 、AsF5 + 、SbF2 + 、SbF3 + 、SbF4 + 、SbF5 + 、WF2 + 、WF3 + 、WF4 + 、WF5 + 、WF6 + CF2 + CF3 + CF4 + 、C2F2 + 、C2F3 + 、C2F4 + 、C2F5 + 、C2F6 + 、GeF2 + 、GeF3 + 、GeF4 + ,Ge2F + 、Ge2F2 + 、Ge2F3 + 、Ge2F4 + 、Ge2F5 + or Ge2F6 + ;and The fluoride ion species are implanted into the substrate.

2. The fluorine ion implantation method of claim 1 , wherein the fluorine ion species comprises a species having a maximum number of fluorine atoms, and the flow rate, arc power, and source magnetic field are selected so that a beam current of the species having a maximum number of fluorine atoms is greater than one or more beam currents of one or more species having a lesser number of fluorine atoms.

3. The fluorine ion implantation method of claim 1, wherein the fluorine ion species is implanted into the substrate at a desired depth with a selected energy and using a selected flow rate, arc power, and source magnetic field.

4. The fluorine ion implantation method according to claim 1, wherein the arc power is in the range of 5 W to 2500 W. The fluorine ion implantation method according to claim 1 , wherein the flow rate is not greater than 10 sccm.

6. The fluorine ion implantation method according to claim 1, wherein the flow rate is in the range of 0.2 sccm to 6 sccm.

7. The fluorine ion implantation method of claim 1, wherein the fluorine compound is selected from the group consisting of: BHF, BHF2, SiHF3, SiH2F2, SiH3F, Si2H3F3, Si2H5F, Si2HF5, GeHF3, GeH2F2, GeH3F, PHF2, PH2F, PH3F2, P2HF, AsHF2, AsH2F, AsH3F2, C n H x F 2n+2-x , C n H x F 2n-x , C n H x F 2n-2-x , COF2, NHF2, NH2F, NHF and N2H3F, wherein n is an integer in the range of 1 to 3, and x is 0, 1 or 2.

8. The fluorine ion implantation method of claim 1, wherein flowing further comprises flowing a hydrogen-containing compound different from the fluorine compound into the ion implanter, wherein the hydrogen-containing compound is selected from the group consisting of: H2, B2H6, SiH4, Si2H6, GeH4, Ge2H6, PH3, AsH3, CH4, C2H6, C x H y , C x H y F z (wherein x and y and z are equal to or greater than 1), NH3 and N2H4, wherein flowing further comprises flowing an oxygen-containing compound other than the fluorine compound into the ion implanter, wherein the oxygen-containing compound is selected from the group consisting of: O2, O3, H2O, H2O2, CO, CO2, NO, NO2, N2O, N4O, N2O3, N2O4, N2O5, N2O6 and COF2, wherein flowing further comprises flowing an inert gas into the ion implanter, wherein the inert gas is selected from the group consisting of: nitrogen, helium, neon, argon, krypton and xenon.

9. The fluorine ion implantation method of claim 8, wherein the hydrogen-containing compound flows into the ion implanter at a rate of 0.01 sccm to 10 sccm.

10. The method of claim 8, wherein two or more of the fluorine compound, the hydrogen-containing compound, the oxygen-containing compound, and / or the inert gas are premixed in a cylinder package.

11. The method of claim 8, wherein two or more of the fluorine compound, the hydrogen-containing compound, the oxygen-containing compound, and / or the inert gas are premixed in a cylinder package and flow together in the same direction.

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