Plasma uniformity control system and method using multiple pulsing

Abstract

The plasma uniformity control system according to one embodiment includes a plasma generating unit that generates plasma by applying pulsed power to a plasma source gas; an ion supply unit that is connected to the plasma generating unit and receives the plasma generated in the plasma generating unit; a plurality of segmented electrodes that are located inside or below the ion supply unit, are electrically independent from each other, and are individually applied with a voltage; and a control unit that controls the supply amount of ions moving to each of the plurality of segmented electrodes in the ion supply unit.

Description

[Technical Field]

[0001] A plasma uniformity control system and method using multiple pulsing is provided. [Background technology]

[0002] Plasma refers to a collection of quasi-neutral ionized gases or particles generated by adding energy to a gas, including neutral particles, electrons, ions, radicals, etc. Here, electrons have a particle number distribution depending on energy, and can be classified into high-energy electrons and low-energy electrons depending on their energy level.

[0003] Ion source technology, including an anion source, is being actively utilized in various technical fields, particularly in the fields of nuclear fusion, semiconductors, and aerospace, such as neutral particle beam injectors for fusion reactor systems in the nuclear fusion field, plasma dry etching process technology in the semiconductor field, and ion thrusters for space propulsion in the aerospace field.

[0004] Mechanisms for generating anions using ion source technology include the surface production mechanism, which generates anions on the surface of an ion source device coated with a material with a low work function, and the volume production mechanism, which generates highly vibrationally excited molecules using high-energy electrons and then generates anions by the reaction between the highly vibrationally excited molecules and low-energy electrons.

[0005] In the field of ion sources, plasma pulsing technology is being used for various purposes, such as increasing the efficiency of negative ion generation. Research is also being conducted on multi-plasma pulsing technology, which can continuously supply plasma ions generated by pulsing and adjust the amount of ion supply according to settings.

[0006] In the field of ion sources, a technology that can control large area uniformity is required to maximize the utility of multi-plasma pulsing technology.

[0007] As related prior art documents, Korean Patent No. 10-1886755 discloses a system and method for continuous negative ion supply using multi-pulse plasma, Korean Patent No. 10-1465542 discloses a plasma process and process control with enhanced charge neutralization, Korean Patent No. 10-0485034 discloses a plasma processing system and method, and Korean Patent No. 10-1328800 discloses a method for controlling pulsed plasma characteristics using multi-frequency RF pulse power. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Registration No. 10-1886755 [Patent Document 2] Korean Patent No. 10-1465542 [Patent Document 3] Korean Patent Registration No. 10-0485034 [Patent Document 4] Korean Patent Registration No. 10-1328800 Summary of the Invention [Problem to be solved by the invention]

[0009] One embodiment is for continuously providing pulsed plasma ions and controlling large area uniformity.

[0010] One embodiment is to control the pulsed plasma ion supply rate over time to exhibit shaping on a time-ion supply rate graph.

[0011] One embodiment is intended for application in a variety of technologies, including neutral particle beam injectors in fusion reactor systems, plasma dry etching process technologies, and ion thrusters in space propulsion.

[0012] In addition to the above object, the embodiments of the present invention can be used to achieve other objects not specifically mentioned. [Means for solving the problem]

[0013] In one embodiment, the plasma uniformity control system controls the pulse power to the plasma. original The plasma generating unit generates plasma by applying a voltage to a source gas; an ion supply unit connected to the plasma generating unit and receiving the plasma generated by the plasma generating unit; a plurality of segmented electrodes located inside or below the ion supply unit, electrically independent from each other, and to which voltages are applied individually; and a control unit that controls the supply amount of ions moving to each of the plurality of segmented electrodes in the ion supply unit.

[0014] In one embodiment, the plasma uniformity control system controls the first pulse power to the first plasma. original a first plasma generating unit that applies a second pulse power having a phase difference with the first pulse power to the source gas to generate a first plasma; original a second plasma generating section for applying a voltage to a source gas to generate a second plasma; an ion supplying section located between the first plasma generating section and the second plasma generating section, connected to the first plasma generating section and the second plasma generating section, and receiving and accommodating the first plasma and the second plasma; a first segmented electrode to which a first voltage is applied; and a second segmented electrode to which a second voltage is applied, the second segmented electrode being located farther from the first plasma generating section than the first segmented electrode and closer to the second plasma generating section than the first segmented electrode; and in the afterglow of the first plasma generating section, the first voltage is greater in magnitude in the negative direction than the second voltage, and the second plasma generating section is in an active glow state.

[0015] A plasma uniformity control method according to one embodiment includes the steps of: measuring the amount of ion supply or the distribution of ion supply at each position for a given time in the ion supply unit or ion utilization unit corresponding to each divided electrode after the plasma generated in the plasma generation unit is transferred to the ion supply unit; individually applying voltages to the plurality of electrically independent divided electrodes by a control unit; and determining whether the amount of ion supply or the distribution of ion supply at each position for a given time in the ion supply unit or ion utilization unit conforms to a user's design based on changes in the voltages of the plurality of divided electrodes. [Effects of the Invention]

[0016] In one embodiment, ions generated by plasma pulsing can be supplied continuously and uniformly over a large area or in a desired distribution, and the amount of ion supply can be controlled over time to shape the amount of ion supply over time. This can be applied to various technologies, including neutral particle beam injectors in nuclear fusion reactor systems, plasma dry etching processes, and ion thrusters for space propulsion systems. [Brief explanation of the drawings]

[0017] [Figure 1a] 1 is a cross-sectional view schematically illustrating a plasma uniformity control system using multiple pulsing according to an embodiment. [Figure 1b] FIG. 1b is a plan view showing multiple segmented electrodes in the system of FIG. 1a. [Figure 1c] 1 is a cross-sectional view schematically illustrating a plasma uniformity control system using multiple pulsing according to an embodiment. [Figure 2a] 1A is a graph showing a pulse power profile applied to each plasma generating unit and a voltage profile over time applied to each electrode for multiple plasma generating units and divided electrodes in the plasma uniformity control system using multiple pulsing of FIG. 1A. [Figure 2b]1A is a graph showing a pulse power profile applied to each plasma generating unit and a voltage profile over time applied to each electrode for multiple plasma generating units and divided electrodes in the plasma uniformity control system using multiple pulsing of FIG. 1A. [Figure 3a] 2a is a graph showing the amount of anion supply versus time for each position (AE) obtained by applying the pulse power and electrode voltage set in FIG. 2a in the system of FIG. 1a. [Figure 3b] 2A is a graph showing time-dependent negative ion density at each position (ae) in the ion source, which appears when the pulse power of FIG. 2A is applied to the system of FIG. 1A. [Figure 4a] 2b is a graph showing the time-dependent amount of positive ions supplied at each position (AE) in the system of FIG. 1a, according to the pulse power and electrode voltage application set in FIG. 2b. [Figure 4b] 2B is a graph showing the time-positive ion density at each position (ae) in the ion source, which is generated by applying the pulse power of FIG. 2B in the system of FIG. 1A. [Figure 5a] 1 is a cross-sectional view schematically illustrating a plasma uniformity control system using multiple pulsing according to an embodiment. [Figure 5b] FIG. 5b is a plan view showing multiple segmented electrodes in the system of FIG. 5a. [Figure 6] FIG. 2 is a plan view illustrating multiple segmented electrodes in a plasma uniformity control system using multiple pulsing according to one embodiment. [Figure 7] FIG. 2 is a perspective view showing a plurality of segmented electrodes according to an embodiment. [Figure 8] 1 is a flowchart showing a method for setting a time-dependent electrode voltage profile to be applied to each segmented electrode by a control unit when a user attempts to form a time-dependent ion (beam) supply amount and distribution desired on an electrode or substrate in an ion supply unit or in an ion utilization unit. [Figure 9] 1 is a graph showing various examples of time-negative ion supply shaping using multiple plasma pulsing techniques. [Figure 10]1 is a flow chart illustrating a control diagram for a plasma uniformity control system using multiple pulsing. DETAILED DESCRIPTION OF THE INVENTION

[0018] With reference to the accompanying drawings, the present invention will be described in detail with reference to the embodiments so that those skilled in the art can easily carry out the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts unnecessary for explanation are omitted, and the same reference numerals are used throughout the specification for the same or similar components. Furthermore, in the case of well-known publicly known technologies, detailed descriptions thereof are omitted.

[0019] Throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0020] Throughout the specification, ion supply is meant to include either ion density or ion flux.

[0021] Throughout the specification and drawings, points A to E and points a to e refer to the surface of the object or the space at that point.

[0022] Throughout the specification and drawings, the plasma uniformity control system according to one embodiment may include the components of the system described in Korean Patent Registration No. 10-1886755, if necessary.

[0023] Hereinafter, a plasma uniformity control system and method using multi-pulsing according to an embodiment will be described.

[0024] FIG. 1a is a cross-sectional view of a plasma uniformity control system using multi-pulsing according to an embodiment. FIG. 1b is a plan view of multiple segmented electrodes in the system of FIG. 1a. FIG. 1c is a cross-sectional view of a plasma uniformity control system using multi-pulsing according to an embodiment. FIG. 2a is a graph showing the pulse power profile applied to each plasma generation unit and the time-dependent voltage profile of the voltage applied to each electrode for multiple plasma generation units and segmented electrodes in the plasma uniformity control system using multi-pulsing of FIG. 1a. As an example, the time-dependent voltage profile is set to provide the target anion supply amount X' under the uniform distribution of FIG. 3a or the target anion density X under the uniform distribution of FIG. 3b corresponding to X' at the AE position on the electrode or substrate. FIG. 3a is a graph showing the time-dependent anion supply amount per position (AE) obtained by applying the pulse power and electrode voltage set as shown in FIG. 2a in the system of FIG. 1a. Since the target anion supply amount per position (AE) is the same as X', the distribution of the target anion supply amount is uniform. Figure 3b is a graph showing the time-anion density for each position (ae) when there is no ion flux control by multiple segmented electrodes or when the same voltage is applied to multiple segmented electrodes, where X is the target anion density at the corresponding ae position when attempting to provide the same ion supply (or flux) of X' at the AE position on the electrode or substrate.

[0025] 1a and 1b, a plasma uniformity control system 1 using multiple pulsing includes a plasma generating unit 110, an ion supply unit 120, a plurality of segmented electrodes 160, and a control unit .

[0026] The plasma uniformity control system 1 can control the uniformity of the ion supply rate at various positions over a large area by adjusting the voltages individually applied to the multiple segmented electrodes 160 using the controller 130. For example, the ion supply rate at points A to E may be substantially the same, or the overall distribution of the ion supply rate at points A to E may have various shapes, such as a bell-shaped, angular, or sloped shape.

[0027] The plasma generator 110 may include a plurality of plasma generators 110a and 110b and may be controlled by the controller 130. The plasma generator 110 may include additional components, such as an impedance matcher, a power supply, and an antenna, required for plasma generation, as needed. The plasma generating unit 110 may be supplied with gas by a gas supply device. The plasma generating unit 110 may include two or more plasma generating units as needed. Referring to FIG. 2a, the plurality of plasma generating units 110a and 110b have a phase difference and apply pulsed power to generate plasma. original The plasma source gas is applied to generate plasma. Therefore, at a specific position in the ion supply unit 120 of FIG. 1(a), ions of a specific density can be continuously supplied regardless of time. Multiple plasma pulsing in the system 1 makes the supply of pulsed plasma ions continuous, making the system 1 suitable for devices that require constant or continuous ion supply and utilization.

[0028] For example, plasma original The source gas may include an electronegative gas that can produce negative ions in a plasma state. original When the source gas includes an electronegative gas, the generated plasma may include anions, highly vibrationally excited molecules of the anion precursor, high energy electrons, and low energy electrons.

[0029] Pulsed power refers to pulsed plasma generating power and includes both an ON state in which power is applied and an OFF state in which power is not applied. The ON state or its time period in which power is applied is called active glow, and the OFF state or its time period in which power is not applied is called afterglow. For example, referring to FIG. 3b, in the first plasma generating unit 110a, the active glow is in the time periods t1-t2 and t3-t4, and the afterglow is in the time period t2-t3. In the second plasma generating unit 110b, the active glow is in the time period t5-t6, and the afterglow is in the time period t6-t7.

[0030] In the active glow, the density of highly vibrationally excited molecules is high because there are many high-energy electrons involved in anion annihilation reactions and the generation of highly vibrationally excited molecules due to the power in the ON state, but the density of highly vibrationally excited molecules is low compared to the afterglow. In the afterglow, the density of highly vibrationally excited molecules and low-energy electrons involved in anion annihilation reactions is very low, and the density of highly vibrationally excited molecules and low-energy electrons is maintained at a level necessary for the anion generation reaction, so the density of highly vibrationally excited molecules is high compared to the active glow. Subsequently, the density of highly vibrationally excited molecules gradually decreases due to factors such as the consumption of low-energy electrons and highly vibrationally excited molecules due to the anion generation reaction. Therefore, by connecting multiple plasma generators 110a and 110b to the ion supply unit 120, when one plasma generator 110 is in the active glow and the amount of anions supplied is low, the other plasma generators 110 are in the afterglow to compensate for the amount of anions supplied, the total amount of anions supplied to the ion supply unit 120 from the multiple plasma generators 110a and 110b at a specific position can be maintained constant over time. For example, since negative ions are generated at a high density in the afterglow, the supply of negative ions that decreases in the active glow of the first plasma generating unit 110a (the period t3-t4 at point c in Figure 3b) can be compensated for by supplying negative ions generated in the afterglow of the second plasma generating unit 110b (the same time period at point c in Figure 3b).

[0031] Each of the plurality of plasma generators 110a, 110b may include an inductively coupled plasma (ICP) device, an electron cyclotron resonance (ECR) plasma device, a microwave plasma device, a filament discharge plasma device, a radio frequency plasma device, a helicon plasma device, a capacitively coupled plasma (CCP) device, etc. The plurality of plasma generators 110a, 110b may be the same or different from each other, and may be configured with various combinations of plasma devices.

[0032] The plasma generated in each of the plasma generators 110a and 110b is transferred to the ion supplier 120 connected to the plasma generators 110a and 110b. For example, the ion supplier 120 may receive and accommodate anions generated in the plasma generators 110. The ion supplier 120 may also include a space where anions are generated by reaction between anion precursors transferred from the plasma generator 110 and low-energy electrons.

[0033] A plurality of segmented electrodes 160 may be located in the lower interior of the ion supply unit 120. For example, a plurality of segmented electrodes 160 may be used in a semiconductor process using a large-area substrate, thereby enabling ions to be supplied to the substrate while appropriately controlling the desired ion supply amount, ion distribution, ion energy, etc. The plurality of segmented electrodes 160 are electrically independent, and may be configured in various numbers and have various shapes.

[0034] The multiple segmented electrodes 160 may be positioned on substantially the same plane or curved surface. The control unit 130 may individually apply a voltage that varies over time to each of the multiple segmented electrodes 160, or the multiple segmented electrodes 160 may have different potentials. By setting the difference between the potential of each of the multiple segmented electrodes 160 and the plasma space potential inside the neighboring ion supplier 120 to be different, the flux of ions moving to each of the multiple segmented electrodes 160 within the internal space of the ion supplier 120 can be controlled. The ion density distribution at a position (ae) inside the ion supplier 120 varies in distance from each of the multiple plasma generators 110a and 110b, resulting in non-uniformity in the ion supply amount (see FIG. 3b) that varies over time. This non-uniformity can lead to non-uniformity in the ion flux distribution on the segmented electrodes 160. Therefore, the non-uniformity in the ion flux distribution can be alleviated by controlling the ion flux, or the distribution can be adjusted to have a specific shape at any time according to user design.

[0035] Referring to FIG. 2A as an example relating to the control of uniform distribution of anions, at a specific time point (t2+t3) / 2 of the afterglow of the first plasma generation unit 110a, the multiple segmented electrodes 160 can be controlled so that their potentials have a greater negative (-) value the closer they are to the first plasma generation unit 110a. For example, the potentials of the ε-segmented electrode, the δ-segmented electrode, the γ-segmented electrode, the β-segmented electrode, and the α-segmented electrode can be controlled to have a greater negative (-) value in this order. Also, at a specific time point (t6+t7) / 2 of the afterglow of the second plasma generation unit 110b, the multiple segmented electrodes 160 can be controlled so that their potentials have a greater negative (-) value the closer they are to the second plasma generation unit 110b. For example, the potentials of the α-segmented electrode, the β-segmented electrode, the γ-segmented electrode, the δ-segmented electrode, and the ε-segmented electrode can be controlled to have a greater negative (-) value in this order.

[0036] Referring to FIG. 3b, at a specific time point ((t2 + t3) / 2) in the afterglow of the first plasma generator 110a, point a is closer to the first plasma generator 110a, where a large amount of anions and anion precursors are generated, than point c. Therefore, the amount (flux) of ions reaching point a is greater than the amount (flux) of ions reaching point c. Therefore, if the ion flux is not controlled by the multiple segmented electrodes 160 or the same voltage is applied to the multiple segmented electrodes 160, the amount (flux) of ions reaching point A will also be greater than the amount (flux) of ions reaching point C. Therefore, if the α-segmented electrode potential is significantly increased in the negative direction compared to the γ-segmented electrode potential at a specific time point ((t2 + t3) / 2) in the afterglow, the change in the flux of anions moving from point a to point A due to the distribution of the electric field at that point will be smaller than the change in the flux of anions moving from point c to point C. Because the anion density at point a is higher than the anion density at point c, the anion flux at points A and C can be controlled to be equal to X', as shown in Figure 3a. However, at a specific point (t2 + t3) in the afterglow of the first plasma generator 110a, point e is farther from the first plasma generator 110a than point c, so the amount (flux) of ions reaching point e from the first plasma generator 110a is smaller than the amount (flux) of ions reaching point c. If the ion flux were not controlled by the multiple segmented electrodes 160 or if the same voltage were applied to the multiple segmented electrodes 160, the anion flux at point E would also be smaller than the anion flux at point C. As a result, by significantly increasing the potential applied to the ε-segmented electrode in the positive direction relative to the γ-segmented electrode potential at a specific time point ((t2+t3) / 2) of the afterglow, the change in the flux of anions moving from point e to point E can be made greater than the change in the flux of anions moving from point c to point C. Because the anion density at point e is lower than the anion density at point c, the amount of ions supplied from the first plasma generating unit 110a to point E can be controlled to be substantially the same as that at point C and X'.In this manner, the potentials of the β and δ divided electrodes can be adjusted to control the amount of ions supplied to points B and D. In a similar manner, the amount of ions supplied to point AE can be controlled to be substantially the same as X', as shown in FIG. 3a, by controlling the voltage applied to the divided electrodes at a specific time point (t6+t7) / 2 of the afterglow of second plasma generator 110b.

[0037] An example relating to the control of uniform distribution of cations will be described below with reference to FIGS. 2b, 4a and 4b.

[0038] FIG. 2b is a graph showing the applied pulse power profile of each plasma generator and the applied voltage profile of each electrode over time, which differ from the configuration of FIG. 2a, for multiple plasma generators and segmented electrodes in the plasma uniformity control system using multiple pulsing of FIG. 1a. As an example, the time-dependent voltage profile here is a profile set to provide the target cation supply amount Y' under the uniform distribution of FIG. 4a or the target cation density Y under the uniform distribution of FIG. 4b below, which corresponds to Y', at the AE position on the electrode or substrate. FIG. 4a is a graph showing the cation supply amount over time by position (AE) obtained by applying the pulse power and electrode voltage set as shown in FIG. 2b in the system of FIG. 1a. Here, since the target cation supply amount per position (AE) is the same as Y', the distribution of the target cation supply amount is a uniform distribution. FIG. 4b is a graph showing the cation density over time by position (AE) in the ion supply unit when the pulse power profile of FIG. 2b is applied to the system of FIG. 1a, and there is no ion flux control by multiple segmented electrodes or when the same voltage is applied to multiple segmented electrodes. Here, Y is the target positive ion density at the corresponding ae position when the ion supply amount (or flux) is to be the same as Y' at the AE position on the electrode or substrate.

[0039] The specific time t of the active glow of the first plasma generating unit 110a A2b, the divided electrodes 160 can be controlled so that the closer they are to the first plasma generating unit 110a, the greater their potentials become in the positive (+) direction. For example, the divided electrodes 160 can be controlled so that the potentials become greater in the positive (+) direction in the order of the ε-divided electrode, the δ-divided electrode, the γ-divided electrode, the β-divided electrode, and the α-divided electrode.

[0040] Also, at a specific time t B The multiple divided electrodes 160 can be controlled so that the closer they are to the second plasma generating unit 110b, the greater their potentials will be in the positive (+) direction. For example, the α-divided electrode, the β-divided electrode, the γ-divided electrode, the δ-divided electrode, and the ε-divided electrode can be controlled so that their potentials have greater values ​​in the positive (+) direction in this order.

[0041] Referring to FIG. 4b, at a specific time t A Since point a is closer to the first plasma generating unit 110a where a large amount of positive ions are generated than point c, the amount (flux) of ions reaching point a is greater than the amount (flux) of ions reaching point c. Therefore, if there is no control of ion flux by the multiple divided electrodes 160 or if the same voltage is applied to the multiple divided electrodes 160, the amount (flux) of ions reaching point A will also be greater than the amount (flux) of ions reaching point C. As a result, at a specific time t of the active glow, A Therefore, if the α-split electrode potential is increased more positively than the γ-split electrode potential, the change in the cation flux moving from point a to point A due to the distribution of the electric field at that point will be smaller than the change in the cation flux moving from point c to point C. Since the cation density at point a is higher than the cation density at point c, the cation flux at points A and C can be controlled to be equal to Y' as shown in FIG. 4a. However, at a specific time t of the active glow of the first plasma generating unit 110a, ASince point e is farther from the first plasma generating unit 110a than point c, the amount (flux) of ions reaching point e from the first plasma generating unit 110a is smaller than the amount (flux) of ions reaching point c. If there is no control of ion flux by the multiple segmented electrodes 160 or if the same voltage is applied to the multiple segmented electrodes 160, the positive ion flux at point E will also be smaller than the positive ion flux at point C. At a specific time t of the active glow A Therefore, by increasing the potential applied to the ε-segmented electrode in the negative direction more than the γ-segmented electrode potential, the change in the flux of cations moving from point e to point E can be made larger than the change in the flux of cations moving from point c to point C. Since the cation density at point e is lower than the cation density at point c, the ion supply amount reaching point E from the first plasma generating unit 110a can be controlled to be substantially the same as point C and Y'. In this manner, the ion supply amount to points B and D can be controlled by adjusting the β- and δ-segmented electrode potentials. In a similar manner, the ion supply amount to points B and D can be controlled at a specific time t of the active glow of the second plasma generating unit 110b. B By controlling the voltage applied to the split electrodes, the ion supply amount reaching the AE point can be controlled to be substantially the same as Y', as shown in FIG. 4a.

[0042] The control unit 130 can control the plurality of plasma generators 110a and 110b. For example, the control unit 130 can appropriately control the magnitude, application time point, repetition frequency, pulse width, duty cycle, and phase difference between the plurality of power pulses supplied to the plasma generator 110. The control unit 130 can also control the voltage characteristics of the plurality of segmented electrodes 160. For example, the control unit 130 can individually control the magnitude of the voltage supplied to each of the plurality of segmented electrodes 160 over time.

[0043] The plasma uniformity control system 1 using multiple pulsing may optionally include a magnetic field filter 150 .

[0044] The magnetic field filter 150 is disposed between the plasma generator 110 and the ion supplier 120 and configured to form a magnetic field. The magnetic field filter 150 may be disposed at the connection portions 151a and 151b where the plasma generator 110 is connected to the ion supplier 120. Alternatively, the magnetic field filter 150 may be disposed near the plasma generator 110 or the ion supplier 120. The magnetic field filter 150 may be configured to form a magnetic field to restrict high-energy electrons generated in the plasma generator 110 in an active glow state from moving to the ion supplier 120, thereby maintaining a high density of anions in the ion supplier 120 and improving the continuity of the anion supply.

[0045] The magnetic field filter 150 may include multiple magnetic field filters 150a and 150b, and may be an electromagnetic magnetic field filter, a permanent magnet magnetic field filter, or the like. Each of the multiple magnetic field filters 150a and 150b may be configured with various combinations of magnetic field filters. Here, the electromagnetic magnetic field filter may include an electromagnet power supply device and an electromagnet, and the magnitude of the magnetic field may be adjusted according to the operating state of the plasma generator 110 in conjunction with (or synchronized with) the phase difference of the pulsed power by the controller 130. For example, the electromagnetic magnetic field filter may form a magnetic field using the active glow of the plasma generator 110 to restrict high-energy electrons generated within the plasma generator 110 from moving to the ion supplier. The electromagnetic magnetic field filter may also form a constant magnetic field without changing over time, or may operate with a delay for a specific time.

[0046] The permanent magnetic field filter is easy to install, more economical than the electromagnetic magnetic field filter, and capable of restricting the movement of high-energy electrons.

[0047] Instead of providing a magnetic field filter 150, the ions and ion precursors can be diffused or transported to the ion supply section 120 while controlling the electron temperature by adjusting the volume or shape of the plasma generation section 110 or the ion supply section 120, or by adjusting the size or shape of the connection sections 151a, 151b between the plasma generation section 110 and the ion supply section 120.

[0048] Referring to FIG. 1c, multiple segmented electrodes 160 can be used in a dual or multiple configuration to locally adjust the electric field between the ae point and the AE point. In FIG. 1c, the upper electrode 160 and the lower electrode 190 may be positioned on either side of an ion irradiation target, such as a wafer (not shown), in the ion supply unit 120. Either the upper electrode 160 or the lower electrode 190 may be configured with multiple segmented electrodes, or both may be configured with multiple segmented electrodes. For example, the segmentation methods shown in FIG. 6 or FIG. 7 may be applied to both electrodes in the same or different ways. For example, the ion irradiation target or substrate may be placed on a single electrode 190 located below the ion supply unit 120, and multiple segmented electrodes 160 may be located above the ion supply unit 120. The plasma uniformity control system 1 using multiple pulsing shown in FIG. 1c can be effectively used to overcome the situation in which it is difficult to place an ion irradiation target on multiple segmented electrodes 160 to which different voltages are applied, as shown in FIG. 1a. For example, if a metal conductor is placed on split electrodes to treat an ion irradiation target and the system is operated by applying different voltages to each electrode, a short circuit may occur between the split electrodes because metal conductors conduct electricity. This may cause a malfunction of the system or the voltage supply device. However, if the substrate itself is placed below the ion supply unit or if the substrate is placed on a single lower electrode and an upper split electrode is used, short circuits and malfunctions may not occur.

[0049] Depending on the purpose of use, a substrate (not shown) may be simply placed in place of the single electrode 160b located below the ion supply unit 120 in Fig. 1c. In this case, the plurality of segmented electrodes 160 are not dualized or multi-dimensional, but are placed only above the ion supply unit 120, and locally adjust the electric field between the ae point and the AE point on the substrate.

[0050] 1a and 1b, the principles of the plasma uniformity control system 1 using multi-pulsing of FIG. 1a and 1b described above can be applied to the configuration of the plasma uniformity control system 1 using multi-pulsing of FIG. 1c that overlaps with the configuration of the plasma uniformity control system 1 using multi-pulsing of FIG. 1a and 1b. Furthermore, the plasma uniformity control system 1 using multi-pulsing of FIG. 1c can partially apply the explanations of the graphs of FIG. 2a and 2b showing pulse power profiles applied to multiple plasma generators and segmented electrodes and voltage profiles applied to each electrode over time for controlling the distribution of anion and cation supply amounts, the graph of FIG. 3a showing the anion supply amount versus time at each position resulting from the application of a set pulse power and electrode voltage, the graph of FIG. 3b showing the anion density versus time at each position in the ion supply unit resulting from the application of pulse power, the graph of FIG. 4a showing the cation supply amount versus time at each position resulting from the application of a set pulse power and electrode voltage, and the graph of FIG. 4b showing the cation density versus time at each position in the ion supply unit resulting from the application of pulse power. The principle of this technology to be considered when applying it is to locally control the magnitude of the electric field with time between the ae point and the AE point to adjust the amount of ions supplied to the AE point.

[0051] Figure 5a is a schematic cross-sectional view of a plasma uniformity control system using multiple pulsing that can be used when using an ion beam or when using ions and an ion beam in a space different from the ion source, according to one embodiment, and Figure 5b is a plan view showing multiple segmented electrodes in the system of Figure 5a.

[0052] 5a and 5b, the plasma uniformity control system 1 using multi-pulsing may include an ion utilization unit 170. The ion utilization unit 170 is a space from which an ion beam with controlled uniformity can be extracted and utilized through the plurality of segmented electrodes 160. Each of the plurality of segmented electrodes 160 may have a plurality of holes formed therein, and an ion beam with controlled uniformity can be extracted from the ion supply unit 120 to the ion utilization unit 170 through the plurality of holes. The plurality of holes may be configured in various shapes, sizes, numbers, positions, and arrangements. The plurality of segmented electrodes 160 may also include spaces through which cooling water flows, thereby increasing the cooling efficiency of the plurality of segmented electrodes 160.

[0053] Among the configurations of the plasma uniformity control system 1 using multiple pulsing of Figures 5a and 5b, the description of the plasma uniformity control system 1 using multiple pulsing of Figures 1a and 1b above can be applied to the configurations that overlap with those of the plasma uniformity control system 1 using multiple pulsing of Figures 1a and 1b. 5a and 5b, the plasma uniformity control system 1 using multiple pulsing can be applied to the graphs of FIGS. 2a and 2b showing pulse power profiles applied to multiple plasma generators and segmented electrodes and voltage profiles over time applied to each electrode for controlling the distribution of anion (beam) and cation (beam) supply, the graph of FIG. 3a showing the amount of anion (beam) supply versus time at each position resulting from the application of a set pulse power and electrode voltage, the graph of FIG. 3b showing the amount of anion density versus time at each position in the ion supply unit resulting from the application of pulse power, the graph of FIG. 4a showing the amount of cation (beam) supply versus time at each position resulting from the application of a set pulse power and electrode voltage, and the graph of FIG. 4b showing the amount of cation density versus time at each position in the ion supply unit resulting from the application of pulse power. Ions can be supplied in the form of a beam at the AE point.

[0054] FIG. 6 is a plan view of a plurality of segmented electrodes of a plasma uniformity control system using multiple pulsing that can be utilized to adjust radial and circumferential ion (beam) supply distributions, according to one embodiment.

[0055] 6, the plurality of segmented electrodes 160 includes 18 segmented electrodes a1-a6, b1-b6, and c1-c6. Two to six plasma generators (not shown) may be arranged surrounding the plurality of segmented electrodes 160, and pulsed plasma may be generated alternately by pulsed power having a phase difference. Voltages having a voltage profile for a specific time are applied to the plurality of segmented electrodes a1-a6, b1-b6, and c1-c6 individually by the control unit 130 in coordination with the phase difference of the pulsed power, thereby adjusting the amount of ion (beam) supply at various positions and controlling its distribution. For example, for uniform distribution control of the amount of negative ions (beam) supplied, when the plasma generating unit located outside the c1 segmented electrode becomes an afterglow and the plasma generating unit located outside the c4 segmented electrode becomes an active glow, the potentials of the c4 segmented electrode, b4 segmented electrode, a4 segmented electrode, a1 segmented electrode, b1 segmented electrode, and c1 segmented electrode applied to the plurality of segmented electrodes 160 can be set to have increasing values ​​in the negative (-) direction, as shown in Figure 2a. In contrast, when the plasma generating unit located outside the c4 segmented electrode becomes an afterglow and the plasma generating unit located outside the c1 segmented electrode becomes an active glow, the potentials of the c1 segmented electrode, b1 segmented electrode, a1 segmented electrode, a4 segmented electrode, b4 segmented electrode, and c4 segmented electrode applied to the plurality of segmented electrodes 160 can be set to have increasing values ​​in the negative (-) direction. Similarly, the a2, b2, c2 divided electrode, a3, b3, c3 divided electrode, a5, b5, c5 divided electrode, and a6, b6, c6 divided electrode can also adjust the voltage magnitude for each time depending on the state of multiple plasma generating units that can be located outside c2-3 and c5-6, thereby allowing the user to obtain the desired ion (beam) supply distribution.

[0056] FIG. 7 is a perspective view showing a plurality of segmented electrodes when a multi-structure electrode is to be applied to a plasma uniformity control system using multi-pulsing according to an embodiment.

[0057] Referring to FIG. 7, a plurality of segmented electrodes 161 in a first layer and a plurality of segmented electrodes 162 in a second layer are spaced apart in the vertical direction. This structure allows for more flexible control of ion beam extraction and acceleration than a structure with multiple segmented electrodes. Each of the multiple segmented electrodes 161 in the first layer and the multiple segmented electrodes 162 in the second layer can be configured with a specific shape, and the spacing between them, voltage, etc. can be set. Alternatively, the multiple segmented electrodes 160 can be configured in a multi-layered form with three or more layers.

[0058] Furthermore, a magnetic field generating and controlling device can be added to the multiple segmented electrodes 160 to adjust the movement of electron (beam), ion (beam), etc. For example, by including an electromagnet or permanent magnet around the multiple segmented electrodes 160 or by passing a current through the multiple segmented electrodes 160 to form a magnetic field, it is possible to adjust the electron (beam), ion (beam) flux, etc.

[0059] 8 is a flowchart showing a method for setting a time-dependent electrode voltage profile to be applied to each of a plurality of segmented electrodes by the control unit when a user desires to obtain a time-dependent ion (beam) supply amount and distribution in the ion supply unit 120 or the ion utilization unit 170. The plasma uniformity control system 1 using multi-pulsing shown in FIGS. 1 to 7 can be applied to the flowchart of FIG. 8.

[0060] The setting of the voltage profile for the segmented electrodes can be explained with reference to FIG. 8. First, the user installs a diagnostic device capable of measuring the ion (beam) supply amount (density, current, or flux) over time at the AE point (or a nearby area corresponding to the AE) in the ion supply unit 120 of FIG. 1A or the AE point (or a nearby area corresponding to the AE) in the ion utilization unit 170 of FIG. 5A corresponding to each segmented electrode 160. In the first step, the user measures the ion (beam) supply amount over the entire plasma pulsing period for each point for initial setup (S10). Here, the ion (beam) supply amount can be measured using a diagnostic device such as an electrostatic probe or a small Faraday cup. Based on the diagnostic data, the user can obtain information on the ion (beam) supply amount and distribution over time and at each position.

[0061] Next, voltages are applied individually to the plurality of divided electrodes 160 (S20). Voltages that vary over time can be applied individually to each of the plurality of divided electrodes 160 by the control unit 130. This can change the amount and distribution of ions (beams) supplied over time at the AE point.

[0062] Next, through diagnosis, the amount of change in the amount of ion (beam) supply and the degree of change in distribution at each position over time during the entire plasma pulsing period associated with each voltage change are confirmed (S30).

[0063] Next, it is confirmed whether the changed ion (beam) supply amount and distribution per position match the user's target, and a suitable voltage profile for each segmented electrode is searched for through a feedback process (S40). If the ion (beam) supply amount and distribution per position over time match the user's design (YES), the voltage profile for each segmented electrode set in step S20 is finally applied to the corresponding segmented electrode 160. If the ion (beam) supply amount and distribution per position over time do not match the user's design (NO), the process returns to step S20, where the voltage profiles set in step S20 are corrected and then applied to the multiple segmented electrodes 160.

[0064] In steps S10 and S30, by providing an additional diagnostic device capable of measuring the time-dependent ion (beam) supply amount and distribution at the ae point (or a nearby area corresponding to ae) in the ion supply unit 120 of Figure 1a or Figure 5a corresponding to each divided electrode 160, and utilizing the time-dependent ion (beam) supply amount and distribution at the ae point and the time-dependent ion (beam) supply amount information of ions moving from the ae point to the AE point, the search work for the voltage profile of each divided electrode in step S40 can be performed more efficiently.

[0065] 9 is a graph showing various examples of time-negative ion supply (or density) shaping using multiple plasma pulsing techniques. The plasma uniformity control system 1 using multiple pulsing shown in FIGS. 1 to 7 can be applied to the graph of FIG. 9.

[0066] Referring to FIG. 9, various time-anion supply profile shaping is possible within the ion supply section by adjusting the number of plasma pulsings in one cycle, pulse sequence, power magnitude, power pulse length, phase difference between pulses, pulse repetition frequency, etc.

[0067] Referring to the first graph of FIG. 9, it can be seen that the ion supply time obtained with a single plasma pulsing can be extended by alternately applying pulsed power only once between the first plasma generator 110a and the second plasma generator 110b. After power is applied, the density of the anions generated by the first plasma generator 110a gradually increases and then gradually decreases due to the afterglow of the first plasma generator 110a. At this time, pulsed power from the second plasma generator 110b, which has the same power magnitude and power pulse length as the power pulse of the first plasma generator 110a, is applied with a certain phase difference. Then, similar to the afterglow of the first plasma generator 110a, the density of the anions generated by the second plasma generator 110b gradually increases and then gradually decreases due to the afterglow of the second plasma generator 110b. The anions generated by the first and second plasma generators 110a and 110b are supplied to the ion supplier 120, so that the amount of anions supplied over time in the ion supplier 120 can have a profile that is similar to an overlapping profile (or a profile that is longer than the supply time from a single plasma generator). By controlling this process, the time period for anion supply in the ion supplier 120 can be extended as desired by the user.

[0068] 9, it can be seen that increasing the phase difference between the power pulses applied to the first and second plasma generators 110a and 110b results in a saddle-shaped time-anion supply rate profile. Conversely, decreasing the phase difference between the power pulses applied to the first and second plasma generators 110a and 110b results in a hill-shaped time-anion supply rate profile that is convex upward.

[0069] 9 with the first graph, it can be seen that when the pulse power magnitudes applied to the first and second plasma generators 110a and 110b are different from each other, an asymmetric anion supply rate profile based on the midpoint of the ion supply time is formed. For example, when the pulse power magnitude applied to the second plasma generator 110b is set to be greater than the pulse power magnitude applied to the first plasma generator 110a, it can be seen that a saddle-shaped time-anion supply rate profile is formed in which the anion supply rate in the midpoint-to-end point region is greater than the anion supply rate in the ion supply start-to-midpoint region.

[0070] 9 compared with the first graph, a method of applying pulsed power to rapidly decrease the anion supply rate in a time-anion supply rate profile can be seen. For example, if power is applied again to the second plasma generator 110b as shown in the fourth graph during a time period in which the anion density gradually decreases due to the afterglow of the second plasma generator 110b in the first graph, the state of the second plasma generator 110b becomes an active glow, and a large number of high-energy electrons are generated, eliminating the anions and rapidly decreasing the anion supply rate.

[0071] 10 is a flow chart showing a control diagram of the plasma uniformity control system using multiple pulsing. The plasma uniformity control system 1 using multiple pulsing shown in FIGS. 1 to 7 and the graph shown in FIG. 9 can be applied to the flow chart of FIG.

[0072] 10, first, the characteristics of the pulsed power applied to the plurality of plasma generators 110, which can change over time, such as the divided electrode voltage and the electromagnet power (or current), are adjusted by the control unit 130. For example, the characteristics of the pulsed power include the number of plasma pulsations per cycle, the pulse sequence, the power magnitude, the power pulse length, the phase difference between pulses, and the pulse repetition frequency.

[0073] The adjusted pulsed power is then applied to the plurality of plasma generating units 110 to form a time-negative ion supply profile that meets the user's design.

[0074] Furthermore, by selectively adjusting not only the pulse power of the plasma generating unit 110 but also the power (or current) applied to each of the multiple electromagnetic magnetic field filters and the voltage characteristics applied to each of the multiple segmented electrodes, it is possible to realize a plasma uniformity control system 1 using multiple pulsing with ion (beam) supply amount and distribution (or uniformity) by time and position that matches the user's design, or to achieve more precise time-anion supply amount profile control.

[0075] The plasma uniformity control system 1 using multi-pulsing described in Figures 1 to 10 can be applied to various technologies including neutral particle beam injectors in nuclear fusion reactor systems, plasma dry etching process technologies, ion thrusters in the space propulsion field, and ion sources for accelerators.

[0076] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims

1. a plasma generating unit that applies pulsed power to a plasma raw material gas to generate plasma; an ion supplier connected to the plasma generator and configured to receive and store the plasma generated by the plasma generator; a plurality of segmented electrodes that are electrically independent of one another and to which voltages are applied individually; and a control unit that controls the supply amount of ions that move to each of the plurality of segmented electrodes by the ion supply unit; the control unit applies voltages to the plurality of divided electrodes without polarity restriction, and applies voltages that change over time to the plurality of divided electrodes individually; the plurality of divided electrodes include a first divided electrode and a second divided electrode, the first divided electrode is located closer to the plasma generating unit than the second divided electrode, and when the plasma generating unit is in an after-glow state, a potential applied to the second divided electrode is higher than a potential applied to the first divided electrode; When the plasma generating unit is in an active-glow state, a potential applied to the second divided electrode is lower than a potential applied to the first divided electrode.

2. The plasma uniformity control system of claim 1 , wherein the control unit adjusts the magnitude of the voltage applied to each of the plurality of segmented electrodes at any given time.

3. The plasma uniformity control system of claim 1 , wherein each of the plurality of segmented electrodes includes a plurality of holes.

4. 2. The plasma uniformity control system of claim 1, wherein the plurality of segmented electrodes are configured in multiple layers, including a first layer of segmented electrodes and a second layer of segmented electrodes.

5. The plasma uniformity control system of claim 1 , further comprising an ion utilization section that extracts the ions.

6. 2. The plasma uniformity control system of claim 1, further comprising a magnetic field filter that forms a magnetic field to restrict high-energy electrons generated in the plasma generating unit in an active-glow state from moving to the ion supply unit.

7. a first plasma generating unit that applies first pulsed power to a first plasma raw material gas to generate a first plasma; a second plasma generating unit that applies second pulse power having a phase difference with the first pulse power to a second plasma raw material gas to generate a second plasma; an ion supplier located between the first plasma generator and the second plasma generator, connected to the first plasma generator and the second plasma generator, and configured to receive and receive the first plasma and the second plasma; a first segmented electrode to which a first voltage is applied; and a second divided electrode to which a second voltage is applied, the second divided electrode being located farther from the first plasma generating portion than the first divided electrode and closer to the second plasma generating portion than the first divided electrode; applying a voltage to the first divided electrode and the second divided electrode without polarity restriction, and applying a voltage that varies with time to the first divided electrode and the second divided electrode individually; When the first plasma generating unit is in an afterglow state, the first voltage has a magnitude greater in a negative direction than the second voltage, and a potential applied to the second divided electrode is higher than a potential applied to the first divided electrode.

10. The plasma uniformity control system according to claim 9, wherein when the second plasma generating unit is in an active glow state, a potential applied to the second divided electrode is lower than a potential applied to the first divided electrode.

8. 8. The plasma uniformity control system of claim 7, wherein when the second plasma generating unit is in an afterglow state, the first voltage has a magnitude greater than that of the second voltage in a positive direction, and the first plasma generating unit is in an active glow state.

9. a plasma generating unit; an ion supply unit; A plurality of segmented electrodes; Aeon Use Department and a controller; and a plasma uniformity control system, the method comprising: After the plasma generated in the plasma generating unit is transferred to the ion supply unit, measuring the amount of ions supplied or the distribution of the amount of ions supplied at any time by position in the ion supply unit or the ion utilization unit corresponding to the segmented electrode; applying voltages individually to the plurality of electrically independent divided electrodes by the control unit; and determining whether the amount of ions supplied or the distribution of the amount of ions supplied by each position at any time in the ion supply unit or the ion utilization unit conforms to a user's design based on the voltage changes of the plurality of segmented electrodes; the control unit applies voltages to the plurality of divided electrodes without polarity restriction, and applies voltages that change over time to the plurality of divided electrodes individually; the plurality of divided electrodes include a first divided electrode and a second divided electrode, the first divided electrode is located closer to the plasma generating portion than the second divided electrode; When the plasma generating unit is in an after-glow state, a potential applied to the second divided electrode is higher than a potential applied to the first divided electrode. When the plasma generating unit is in an active-glow state, a potential applied to the second divided electrode is lower than a potential applied to the first divided electrode.

10. The method of claim 9, wherein the plasma generating unit generates plasma by multiple pulsing.

11. 10. The method of claim 9, wherein the step of individually applying voltages to the plurality of segmented electrodes comprises controlling an amount of ions supplied to each position by each of the plurality of segmented electrodes.

12. 10. The plasma uniformity control method of claim 9, further comprising the step of: applying a corrected voltage to each of the plurality of segmented electrodes individually if the voltage does not match the user's design.

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