KR-102962375-B1 - Fluorinated molecular cavity gas when running dimethylaluminum chloride as a source material to generate an aluminum ion beam

KR102962375B1KR 102962375 B1KR102962375 B1KR 102962375B1KR-102962375-B1

Abstract

An ion implantation system, an ion source, and a method are provided, comprising a gaseous aluminum-based ion source material. The gaseous aluminum-based ion source material may be dimethylaluminum chloride (DMAC) or may contain it, and DMAC is a liquid that transitions to a vapor phase at room temperature. The ion source receives the gaseous aluminum-based ion source material to form an ion beam. A low-pressure gas bottle is passed through a primary gas line DMAC is supplied as a gas to the arc chamber of the ion source. A separate secondary gas line supplies a cavity gas, such as a fluorine-containing molecule, to the ion source, and the cavity gas and DMAC reduce energetic carbon cross-contamination and/or increase dual-charged aluminum.

Inventors

콜빈, 네일
바솜, 네일
무어, 에드워드

Assignees

액셀리스 테크놀러지스, 인크.

Dates

Publication Date: 20260507
Application Date: 20211101
Priority Date: 20201030

Claims (20)

As an ion implantation system for implanting aluminum ions, Electrode power supply; An arc chamber including an electrode—the electrode is electrically coupled to the electrode power supply—; A process gas source containing dimethylaluminum chloride (DMAC); A process gas supply line fluidically coupled to the process gas source and the arc chamber—the process gas supply line is configured to selectively deliver the DMAC from the process gas source to the arc chamber, and the electrode is configured to form a plasma from the DMAC within the arc chamber based at least partially on energy provided to the electrode from the electrode power supply, thereby decomposing the DMAC to form at least C₂H₃ having a mass close to that of atomic aluminum— ; A co-gas source containing a co-gas containing fluorine; and An ion implantation system comprising: a cavity-gas supply line fluidically coupled to the cavity-gas source and the arc chamber—the cavity-gas supply line is configured to selectively deliver the cavity-gas from the cavity-gas source to the arc chamber, the cavity-gas supply line is distinguished from the process gas supply line, and the fluorine is configured to react with at least the C₂H₃ , thereby forming CF₆x and minimizing the amount of C₂H₃ available within the arc chamber.
In paragraph 1, The above process gas source is an ion implantation system that maintains the DMAC in a liquid state.
In paragraph 2, The above process gas source comprises an ion implantation system including a pressurized gas bottle configured to contain the DMAC.
In paragraph 1, An ion implantation system in which the above cavity gas contains a fluorine-containing molecule.
In paragraph 4, An ion implantation system in which the above fluorine-containing molecule comprises BF₃ , SiF₄ , PF₃ , PF₅ , or NF₃ .
In paragraph 1, An ion implantation system comprising a cavity gas including fluorine gas ( F₂ ) and an inert gas mixed at a predetermined concentration.
In paragraph 6, The above inert gas comprises one or more of helium and argon, in an ion implantation system.
In paragraph 1, The above-mentioned joint-gas source comprises one or more pressurized gas sources, in an ion implantation system.
In paragraph 1, An extraction electrode configured to extract an aluminum-based ion beam from the arc chamber based on biasing of the extraction electrode with respect to the arc chamber; and An ion implantation system further comprising: a mass spectrometer located downstream of the extraction electrode—the mass spectrometer is configured to mass analyze the aluminum-based ion beam and remove CF x , thereby defining the mass-analyzed aluminum ion beam and thereby minimizing energetic cross-contamination caused by C₂H₃ in the mass-analyzed aluminum ion beam .
In Paragraph 9, A ceramic target located within the arc chamber is additionally included, An ion implantation system wherein the ceramic target comprises aluminum, and the fluorine is configured to etch the ceramic target.
In Paragraph 10, The above aluminum-based ion beam is an ion implantation system comprising dual-charged aluminum ions.
As a system for injecting aluminum ions into a workpiece, Ion source including the following: An arc chamber comprising one or more electrodes operably coupled to an electrode power supply—the arc chamber further comprises an extraction opening—; A process gas source containing dimethylaluminum chloride (DMAC); A process gas supply line fluidically coupling the process gas source to the arc chamber—the process gas supply line is configured to selectively deliver the DMAC from the process gas source to the arc chamber, and the one or more electrodes are configured to form a plasma from the DMAC within the arc chamber based at least partially on energy provided to the electrodes from the electrode power supply, thereby decomposing the DMAC to form at least C₂H₃ having a mass close to that of atomic aluminum— ; A cavity-gas source containing a cavity-gas containing fluorine; and A cavity-gas supply line fluidically coupling the cavity-gas source to the arc chamber—the cavity-gas supply line is configured to selectively deliver the cavity-gas from the cavity-gas source to the arc chamber, the cavity-gas supply line is distinguished from the process gas supply line, and the fluorine is configured to react with at least the C₂H₃ , thereby forming CF₆x and minimizing the amount of C₂H₃ available within the arc chamber—; An extraction electrode adjacent to the extraction opening of the arc chamber—the extraction electrode is configured to extract an aluminum-based ion beam from the arc chamber based on the biasing of the extraction electrode with respect to the arc chamber—; and A system comprising: a mass spectrometer located downstream of the extraction aperture—the mass spectrometer is configured to mass analyze the aluminum-based ion beam and remove CF x , thereby defining the mass-analyzed aluminum ion beam and thereby minimizing energetic cross-contamination due to C₂H₃ in the mass-analyzed aluminum ion beam .
In Paragraph 12, A system comprising a pressurized gas bottle configured to contain the DMAC, wherein the process gas source described above comprises the above process gas source.
In Paragraph 12, A system in which the above cavity gas comprises one or more of BF₃ , SiF₄ , PF₃ , PF₅ , or NF₃ .
In Paragraph 12, A system comprising a cavity gas including a fluorine gas ( F₂ ) and an inert gas mixed at a predetermined concentration.
In Paragraph 12, A ceramic target located within the arc chamber is additionally included, A system in which the ceramic target comprises aluminum, and the fluorine is configured to etch the ceramic target and increase the beam current of the aluminum-based ion beam.
In Paragraph 16, The above aluminum-based ion beam is a system comprising dual-charged aluminum ions.
As a system for injecting aluminum ions into a workpiece, Ion source including the following: Arc chamber including an extraction opening; One or more electrodes electrically coupled to an electrode power supply; A ceramic target located within the arc chamber—the ceramic target comprises aluminum—; A process gas source containing dimethylaluminum chloride (DMAC) in liquid form; A process gas supply line fluidically coupling the process gas source to the arc chamber—the process gas supply line is configured to selectively deliver the DMAC in gaseous form from the process gas source to the arc chamber, and the one or more electrodes are configured to form a plasma from the DMAC within the arc chamber based at least partially on energy provided to the one or more electrodes from the electrode power supply, thereby decomposing the DMAC to form at least C₂H₃ having a mass close to that of atomic aluminum—; A cavity-gas source containing a cavity-gas containing fluorine; and A cavity-gas supply line fluidically coupling the cavity-gas source to the arc chamber—the cavity-gas supply line is configured to selectively deliver the cavity-gas from the cavity-gas source to the arc chamber, the cavity-gas supply line is distinguished from the process gas supply line, and the fluorine is configured to react with at least the C₂H₃ , thereby forming CF₆x and minimizing the amount of C₂H₃ available within the arc chamber, and the fluorine is configured to etch the ceramic target—; An extraction electrode adjacent to the extraction opening of the arc chamber—the extraction electrode is configured to extract an aluminum-based ion beam from the arc chamber based on the biasing of the extraction electrode with respect to the arc chamber—; and A system comprising: a mass spectrometer located downstream of the extraction aperture—the mass spectrometer is configured to mass analyze the aluminum-based ion beam and remove CF x , thereby defining the aluminum ion beam and thereby minimizing energetic cross-contamination due to C₂H₃ in the aluminum ion beam.
In Paragraph 18, A system configured such that the fluorine etches the ceramic target to increase the beam current of the aluminum-based ion beam.
In Paragraph 16, The above ceramic target is a system comprising Al₂O₃ or AlN .

Description

Fluorinated molecular cavity gas when running dimethylaluminum chloride as a source material to generate an aluminum ion beam <Reference to related applications> This application claims the benefit of U.S. Provisional Application No. 63/107,729 filed on October 30, 2020, the entire contents of which are incorporated herein by reference. Technology Field The present invention generally relates to an ion implantation system, and more specifically, to an ion implantation system configured to generate an ion beam containing aluminum ions from gaseous dimethylaluminum chloride (DMAC). There is an increasing demand for ion implantation using metal ions. For example, aluminum implantation is important in the power device market, which is a small but rapidly growing sector of the market. For many metals, including aluminum, the problem lies in supplying the feed material to the ion source. Systems using a vaporizer, which is a small oven located outside the arc chamber of the ion source, have been previously provided, in which metal salts are heated to generate the appropriate vapor pressure to supply steam to the ion source. However, the oven is located away from the arc chamber, and it takes time to heat to the desired temperature, set the steam flow, start the plasma, and start the ion beam. Furthermore, if a change from one metal species to another is required, time is required to wait for the oven to cool properly for such a change. Another conventional technique involves placing a metal-containing material, such as aluminum or other metals, inside the arc chamber. In the case of aluminum, the metal-containing material may include aluminum oxide, aluminum fluoride, or aluminum nitride, all of which can withstand a temperature of approximately 800°C in the plasma chamber. In such a system, ions are sputtered directly from the material inside the plasma. Another technique involves using a plasma containing an etchant, such as fluorine, to achieve chemical etching of the metal. While acceptable beam currents can be obtained using these various techniques, compounds of aluminum oxide, aluminum chloride, and aluminum nitride, all of which are good electrical insulators, can be used for relatively short periods of time (e.g., (5 to 10 hours) It tends to be deposited on electrodes adjacent to the ion source. As such, various harmful effects are observed, such as high voltage instability and related fluctuations in the dosage of the injected ions. FIG. 1 is a block diagram of an exemplary vacuum system using dimethylaluminum chloride as an ion source material according to some aspects of the present invention. Figure 2 is a graph illustrating various spectra of an aluminum ion beam according to some examples. Figure 3 is a chart illustrating a comparison of various spectral values according to several examples. FIG. 4 illustrates an exemplary method for injecting aluminum ions into a workpiece using dimethylaluminum chloride as a gaseous ion source material. The present invention generally relates to an ion implantation system and an associated ion source material. More specifically, the present invention relates to components for said ion implantation system using dimethylaluminum chloride as an ion source material for generating atomic ions to electrically dope silicon, silicon carbide, or other semiconductor substrates at various temperatures. The present invention advantageously minimizes energetic cross-contamination of carbon in aluminum implantation when using dimethylaluminum chloride as an ion source material. Furthermore, the present invention minimizes various depositions on the extraction electrodes and source chamber components. Thus, the present invention will reduce associated arcing and glitching and further increase the overall lifetime of the ion source and associated electrodes. Accordingly, the present invention will now be described with reference to the drawings, and throughout, the same reference numerals are used to refer to the same components. It will be understood that the description of these embodiments is merely illustrative and should not be interpreted in a restrictive sense. In the following description, numerous specific details are provided for illustrative purposes to provide a complete understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without these specific details. Furthermore, the scope of the invention is not intended to be limited by the embodiments or examples described below with reference to the accompanying drawings, but is intended to be limited only by the appended claims and their equivalents. It should also be noted that the drawings are provided to provide examples of some aspects of the embodiments of the present invention and are therefore to be regarded merely as schematic. In particular, the components depicted in the drawings are not necessarily scaled to one another, and the arrangement of