Multi-step pulse DC waveform generator

Abstract

A pulse generator according to an embodiment of the present invention comprises: a pulse DC generator for providing a pulse DC waveform to a capacitively coupled load; a step waveform generator for providing a step waveform to the capacitively coupled load and which is connected in parallel with the pulse DC generator; and a control part for controlling the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. A waveform applied to the capacitively coupled load comprises a first decrease section in which the voltage decreases from a positive voltage to a negative first voltage, a first maintaining section in which the voltage is maintained at the negative first voltage for a predetermined time, a second decrease section in which the voltage decreases from the first voltage to a second voltage, and a second maintaining section in which the voltage is maintained at the second voltage.

Description

Multi-step pulse DC waveform generator

[0001] The present invention relates to a pulse DC waveform generator, and more particularly, to a multi-step pulse DC waveform generator at a negative voltage at a frequency of tens to hundreds of kHz for controlling ion energy in a plasma process.

[0002] Recent semiconductor processes require advanced technologies such as high-precision technology for forming micropatterns and rapid substrate processing. In semiconductor processes, plasma is generally generated by an RF generator with a frequency of 2 MHz or higher. To increase the processing speed of semiconductor processes, various methods are used, such as increasing the power of the RF generator or changing the frequency. More specifically, a first power supply unit that generates plasma by supplying power of hundreds of watts or more at a frequency of MHz or higher and supplies appropriate plasma particles to the target substrate are used together, and a second power supply unit with a frequency range of tens to hundreds of kHz, whose main purpose is to accelerate the generated plasma particles and inject them into the semiconductor substrate to be processed, are used together.

[0003] Recent semiconductor processes require advanced technologies such as high-precision technology for forming micropatterns and rapid substrate processing. In semiconductor processes, plasma is generally generated using an RF generator with a frequency of 2 MHz or higher. To increase the processing speed of semiconductor processes, various methods are used, such as increasing the power of the RF generator or changing the frequency. More specifically, a first power supply unit that generates plasma by supplying power of hundreds of watts or more at a frequency of MHz or higher and supplies appropriate plasma particles to the target substrate is used together, and a second power supply unit with a frequency range of tens to hundreds of kHz is used to control the energy of the generated plasma particles and inject them into the semiconductor substrate.

[0004] Conventional RF generators can be categorized into primary, secondary, or tertiary power supplies, depending on their respective needs. These conventional RF generators supply sinusoidal power to the plasma load. However, it is well known that power supplies using sinusoidal power supplies, particularly those for supplying ion energy from the plasma to a semiconductor process substrate, have a wide energy range in the ion energy distribution of the plasma due to the sinusoidal nature of the supplied power.

[0005] This existing ion energy distribution causes problems such as etch uniformity, etch selectivity, and etch pattern distortion in increasingly advanced micro-semiconductor processes measuring tens or even nanometers. Furthermore, these problems can negatively impact the yield of semiconductor devices.

[0006] In contrast, a pulsed DC generator is one way to meet the requirements of these high-precision, high-miniaturization semiconductor processing processes. By applying a non-sinusoidal voltage waveform, the incident energy of ions incident from the plasma onto the substrate can be controlled. A pulsed DC generator is characterized by supplying a pulsed voltage waveform to the plasma load, rather than supplying a sinusoidal voltage to the plasma load or the semiconductor processing substrate.

[0007] Conventional pulsed DC generators, which generate square waves, are widely known and used, along with sinusoidal wave generators, even in applications beyond the semiconductor industry. However, when these simple square-wave pulsed DC generators are used for ion energy control in semiconductor plasma reaction processes, the absolute value of the voltage on the wafer or substrate decreases over time. This decrease in wafer voltage can cause the ion energy distribution function (IEDF) to be distributed over a wide energy range. Therefore, simple square-wave pulse waveforms have limitations in controlling the ion energy distribution.

[0008] Therefore, the pulse DC voltage generated by the pulse DC generator proposed in the present invention is not a simple pulse waveform such as a square wave, but rather generates a step-shaped waveform with a negative voltage. The present invention provides a multi-step pulse generator. The multi-step pulse generator can control the ion energy distribution of the plasma, thereby enabling more efficient operation of the plasma process.

[0009] The technical problem to be solved by the present invention is to provide a pulse DC waveform generator that provides an ion energy distribution having at least two peaks by controlling ion energy.

[0010] According to one embodiment of the present invention, a pulse generator includes: a pulse DC generator for providing a pulse DC waveform to a capacitor-coupled load; a step waveform generator for providing a step waveform to the capacitor-coupled load and connected in parallel with the pulse DC generator; and a control unit for controlling the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. The waveform applied to the capacitor-coupled load includes a first decreasing section for decreasing from a positive voltage to a negative first voltage, a first sustaining section for maintaining the negative first voltage for a predetermined period of time, a second decreasing section for decreasing from the first voltage to a second voltage, and a second sustaining section for maintaining the second voltage.

[0011] In one embodiment of the present invention, the pulse DC generator may include a first source stage including at least one of a first voltage source and a first current source; and a first switching stage that switches and outputs an output of the first source stage.

[0012] In one embodiment of the present invention, the first switching stage may be a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter.

[0013] In one embodiment of the present invention, the step waveform generator may include a second source stage including at least one of a second voltage source and a second current source; and a second switching stage that switches and outputs an output of the second source stage.

[0014] In one embodiment of the present invention, the second switching stage may be a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter.

[0015] In one embodiment of the present invention, the pulse DC generator can form a first decreasing section in which the capacitor-coupled load decreases from a positive voltage to a negative first voltage. The step waveform generator can provide the capacitor-coupled load with the first sustain section in which the voltage is maintained at the first voltage, the second decreasing section in which the voltage is reduced from the first voltage to the second voltage, and the second sustain section in which the voltage is maintained at the second voltage.

[0016] In one embodiment of the present invention, the second current source provides a step current, and the second switching stage can provide the step current to the capacitor-coupled load in the second reduction section.

[0017] In one embodiment of the present invention, the step current forms a ramp waveform in the capacitor-coupled load, and the ramp waveform can provide an ion flux between a first energy peak caused by the first voltage and a second energy peak caused by the second voltage.

[0018] In one embodiment of the present invention, the step waveform generator may include a plurality of sub-step waveform generators. Each of the sub-step waveform generators includes a second source stage including a second voltage source; and a second switching stage connected to the second voltage source, and the outputs of the sub-step waveform generators may be connected to each other in a cascade manner.

[0019] In one embodiment of the present invention, the pulse DC waveform generator may include a plurality of sub-pulse DC waveform generators. Each of the sub-pulse DC waveform generators includes a first source stage including a first voltage source; and a first switching stage connected to the first voltage source, and the outputs of the sub-pulse DC waveform generators may be connected to each other in a cascade manner.

[0020] In one embodiment of the present invention, the step waveform generator may include a plurality of sub-step waveform generators. Each of the sub-step waveform generators includes a second source stage including a second current source; and a second switching stage connected to the second current source, and the outputs of the sub-step waveform generators may be connected in parallel with each other.

[0021] In one embodiment of the present invention, the second switching stage includes a first transistor and a second transistor connected in parallel to an output terminal of the second current source; a first diode connected between the first transistor and ground; and a second diode connected in series with the second transistor, and an output of the second switching stage can be provided through the second transistor and the second diode.

[0022] In one embodiment of the present invention, the step waveform generator may include a first sub-step waveform generator and a second sub-step waveform generator. The first sub-step waveform generator may provide a first step current, and the second sub-step waveform generator may provide a second step current different from the first step current.

[0023] In one embodiment of the present invention, the first step current can form a first ramp waveform in the capacitor coupling load, and the second step current can form a second ramp waveform in the capacitor coupling load.

[0024] In one embodiment of the present invention, the pulse DC generator may include a first source stage including a first current source; and a first switching stage that switches and outputs an output of the first source stage. The step waveform generator may include a second source stage including a second current source; and a second switching stage that switches and outputs an output of the second source stage.

[0025] In one embodiment of the present invention, the pulse DC generator provides a pulse current and can control the ion flux according to the ion energy by controlling the application time of the pulse current.

[0026] In one embodiment of the present invention, the step waveform generator provides a step current and can control the ion flux according to the ion energy by controlling the application time of the step current.

[0027] In one embodiment of the present invention, the waveform applied to the capacitor-coupled load may further include a third decreasing section decreasing from the second voltage to a third voltage, and a third maintaining section maintaining the third voltage for a certain period of time.

[0028] According to one embodiment of the present invention, a pulse generator includes: a pulse DC generator providing a pulse DC waveform to a capacitor-coupled load; a step waveform generator providing a step waveform to the capacitor-coupled load and connected in parallel with the pulse DC generator; and a control unit controlling the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator, wherein the waveform applied to the capacitor-coupled load includes a first decreasing section decreasing from a positive voltage to a negative first voltage, a first sustaining section maintained at the negative first voltage for a predetermined period of time, a second decreasing section decreasing from the first voltage to a second voltage, and a second sustaining section maintained at the second voltage. A method of operating the pulse generator includes the steps of: setting the pulse DC waveform and the step waveform; operating the pulse DC generator to form the pulse DC waveform to the capacitor-coupled load; and operating the step waveform generator to form the step waveform to the capacitor-coupled load. The pulse DC waveform includes a first decreasing section decreasing from the positive voltage to a negative first voltage. The step waveform includes a first sustain period in which the first voltage is maintained at a negative level for a predetermined period of time, a second decreasing period in which the first voltage is decreased to a second voltage, and a second sustain period in which the second voltage is maintained.

[0029] According to one embodiment of the present invention, a pulse generator includes: a pulse DC generator for providing a pulse DC waveform to a capacitor-coupled load; a step waveform generator for providing a step waveform to the capacitor-coupled load and connected in parallel with the pulse DC generator; a switching unit for switching outputs of the pulse DC generator and the step waveform generator; and a control unit for controlling the pulse DC generator and the step waveform. The waveform applied to the capacitor-coupled load includes a first decreasing section for decreasing from a positive voltage to a negative first voltage, a first sustaining section for maintaining the negative first voltage for a predetermined period of time, a second decreasing section for decreasing from the first voltage to a second voltage, and a second sustaining section for maintaining the second voltage.

[0030] In one embodiment of the present invention, the pulse DC generator (710) is branched from the output terminal of the current source rectifier (705) and connected to one end of a first inductor (712) to generate a pulse current (Ip), and the step waveform generator (720) is branched from the output terminal of the current source rectifier (705) and connected to one end of a second inductor (722) to generate a step current (Is).

[0031] In one embodiment of the present invention, the pulse DC generator (710) includes: a first transistor having a source connected to the other end of the first inductor; a second transistor having a source connected to the other end of the first inductor; and a first diode connected in series to a drain of the first transistor. The first diode may be connected to one end of the first inductor, and the drain of the second transistor may be connected to an input terminal of the switching unit.

[0032] In one embodiment of the present invention, the step waveform generator includes a third transistor having a source connected to the other terminal of the second inductor; a fourth transistor having a source connected to the other terminal of the second inductor; and a second diode connected in series with a drain of the third transistor. The second diode is connected to one terminal of the second inductor, and the drain of the fourth transistor is connected to an input terminal of the switching unit.

[0033] In one embodiment of the present invention, the switch unit includes: a fifth transistor connected to an output terminal of the pulse DC generator; a sixth transistor connected in series with the fifth transistor; a seventh transistor connected to an output terminal of the pulse DC generator; an eighth transistor connected in series with the seventh transistor; a first inverter diode disposed between the fifth transistor and the output terminal of the pulse DC generator; a second inverter diode disposed between the fifth transistor and the sixth transistor; a third inverter diode disposed between the seventh transistor and the output terminal of the pulse DC generator; and a fourth inverter diode disposed between the seventh transistor and the eighth transistor. A contact point between the fifth transistor and the second diode is connected to one end of the load. A contact point between the seventh transistor and the fourth diode is connected to the other end of the load.

[0034] A pulse DC waveform generator according to one embodiment of the present invention can control a bi-modal ion energy distribution (IEDF) from a low ion energy flux to a high ion energy flux by controlling ion energy.

[0035] A pulse DC waveform generator according to one embodiment of the present invention controls, as major control result factors, a low ion energy level and its peak, a high energy level and its peak, a width of low energy and a width of high energy, and a flux of incident ion energy in an intermediate energy band within the two energies.

[0036] A pulse DC waveform generator according to one embodiment of the present invention can control a bi-modal ion energy distribution (IEDF) from a low ion energy flux to a high ion energy flux by controlling ion energy.

[0037] A pulse DC waveform generator according to one embodiment of the present invention controls, as major control result factors, a low ion energy level and its peak, a high energy level and its peak, a width of low energy and a width of high energy, and a flux of incident ion energy in an intermediate energy band within the two energies.

[0038] FIG. 1 is a conceptual diagram showing a plasma processing device according to one embodiment of the present invention.

[0039] FIG. 2a is a conceptual diagram illustrating a pulse generator according to one embodiment of the present invention.

[0040] Figures 2b and 2c are graphs showing ion flux according to the output voltage and ion energy of the pulse generator of Figure 2a.

[0041] FIG. 3 is a conceptual diagram and output waveform showing a pulse DC generator according to another embodiment of the present invention.

[0042] Figure 4 is a conceptual diagram showing the first source stage of the pulse DC generator of Figure 3.

[0043] FIG. 5 is a conceptual diagram showing a pulse DC generator according to one embodiment of the present invention.

[0044] Figure 6a is a conceptual diagram showing a pulse DC generator according to one embodiment of the present invention.

[0045] Figure 6b is a conceptual diagram showing a pulse DC generator according to one embodiment of the present invention.

[0046] Figure 7 is a conceptual diagram showing a step waveform generator according to one embodiment of the present invention.

[0047] FIG. 8 is a conceptual diagram illustrating a second source stage of a step waveform generator according to one embodiment of the present invention.

[0048] FIG. 9 is a conceptual diagram showing a second switching stage of a step waveform generator according to one embodiment of the present invention.

[0049] FIG. 10A and FIG. 10B are conceptual diagrams showing a second switching stage of a step waveform generator according to one embodiment of the present invention.

[0050] FIG. 11 and FIG. 12 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0051] FIGS. 13 and 14 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0052] FIGS. 15 and 16 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0053] FIG. 17 and FIG. 18 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0054] FIGS. 19 and 20 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0055] FIG. 21 and FIG. 22 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0056] Figure 23 is a flowchart explaining an operating method of a pulse generating device according to one embodiment of the present invention.

[0057] Fig. 24 is a conceptual diagram illustrating a pulse generating device according to another embodiment of the present invention.

[0058] Fig. 25 is a circuit diagram illustrating a pulse DC generator and a step waveform generator of the pulse generator of Fig. 24.

[0059] Fig. 26 is a timing diagram showing the waveform applied to the load of the pulse generator of Fig. 24.

[0060] Figures 27 and 28 are drawings showing the current paths of the pulse DC generator and step waveform generator of Figure 25.

[0061] A pulse generator according to one embodiment of the present invention includes: a pulse DC generator providing a pulse DC waveform to a capacitor-coupled load; a step waveform generator providing a step waveform to the capacitor-coupled load and connected in parallel with the pulse DC generator; and a control unit controlling the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator.

[0062] Each of the pulse DC generator and the step waveform generator can be a current type that outputs current or a voltage type that outputs voltage. Each of the pulse DC generator and the step waveform generator can output voltage and current simultaneously.

[0063] A pulse generator according to one embodiment of the present invention provides pulse DC to a semiconductor processing substrate of an accumulation-coupled or, although not shown in this embodiment, an inductively coupled plasma or electron cyclotron resonance plasma generator or other plasma generator, thereby controlling ion energy distribution in a plasma process, thereby increasing the efficiency of the plasma process.

[0064] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosure is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art. In the drawings, components are exaggerated for clarity. Parts denoted by the same reference numerals throughout the specification represent the same components.

[0065] FIG. 1 is a conceptual diagram showing a plasma processing device according to one embodiment of the present invention.

[0066] Referring to FIG. 1, a plasma processing device (10) includes a chamber (102) forming a vacuum region, an upper electrode (104) disposed within the chamber (102) and supplied with RF power to form plasma, a substrate holder (106) facing the upper electrode (104) and mounting a substrate (W / F), an electrode (108) disposed within the substrate holder (106), and a pulse generator (100) applying a pulse DC waveform to the electrode (108).

[0067] The RF generator (105) applies a sine wave RF power to the upper electrode (104) to generate plasma. The RF generator (105) can generally use a frequency faster than a pulse generator. The frequency of the RF generator (105) is generally 2 MHz or more, and the power value can be hundreds of watts to tens of kilowatts depending on the process. The RF generator (105) can supply power to the upper electrode (104) in the form of a pulse that operates for a predetermined period of time and does not operate for a predetermined period of time, or in the form of a multi-stage pulse in which the applied power varies over time.

[0068] Plasma semiconductor processing devices can typically be divided into capacitively coupled plasma (CCP) structures and inductively coupled plasma (ICP) structures. The plasma within the chamber can process various plasma processes depending on variables such as the type and pressure of the gas. The detailed description of the present invention is based on the capacitively coupled plasma structure, but can be applied to all semiconductor process plasma generating devices including the capacitively coupled plasma and inductively coupled plasma.

[0069] A pulse generator (100) is connected to an electrode (108) of a substrate holder (106). That is, the pulse generator (100) can apply a pulse waveform to a capacitive coupling load. The pulse generator (100) serves to control the energy of ions incident on the substrate. That is, ions incident on the substrate (W / F) can have two or more energy peaks.

[0070] The above substrate (W / F) is separated from the electrode (108) by an insulator. When the substrate (W / F) is treated as a conductor, the electrode, the insulator, and the substrate form a capacitor. The plasma has a plasma potential, and the potential difference between the substrate potential and the plasma potential can determine the energy incident on the substrate (W / F).

[0071] FIG. 2a is a conceptual diagram illustrating a pulse generator according to one embodiment of the present invention.

[0072] Figures 2b and 2c are graphs showing ion flux according to the output voltage and ion energy of the pulse generator of Figure 2a.

[0073] Referring to FIG. 2a, FIG. 2b, and FIG. 2c, the pulse generator (100) is a capacitor-coupled load (Z L) provides a pulse DC waveform to the capacitor-coupled load; a step waveform generator (120) provides a step waveform to the capacitor-coupled load and is connected in parallel with the pulse DC generator (110); and a control unit (130) controls the pulse DC waveform of the pulse DC generator (110) and the step waveform of the step waveform generator (120). The capacitor-coupled load (Z) L ) includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first sustaining section (②) maintained at the negative first voltage (V1) for a certain period of time, a second decreasing section (③) decreasing from the first voltage (V1) to a second voltage (V2), and a second sustaining section (④) maintained at the second voltage (V2).

[0074] A multi-step pulse DC waveform generator (100) according to one embodiment of the present invention determines a relatively low ion energy of a first pulse amplitude (V0-V1) by a positive voltage (V0) and a negative first voltage (V1).

[0075] The first sustain period (②) of the first pulse determines the peak of the incident ion flux with ion energy determined by the first pulse amplitude (V0-V1). That is, as the first sustain period (②) of the first pulse increases, the peak of the ion flux increases.

[0076] The second pulse amplitude (V0-V2) determines a relatively high ion energy by the positive voltage (V0) and the negative second voltage (V2).

[0077] The second sustain period (④) of the second pulse determines the peak of the incident ion flux with ion energy determined by the second pulse amplitude (V0-V2). That is, as the second sustain period (④) of the second pulse increases, the peak of the ion flux increases.

[0078] Capacitor-coupled load (Z L ) may include a substrate and an electrode (108) forming a capacitor. The substrate (W / F) may be a semiconductor substrate. Plasma may be formed on the substrate (W / F) by another energy application means.

[0079] The pulse DC generator (110) may include a first source stage (112) including a first voltage source and / or a first current source; and a first switching stage (114) that switches and outputs an output of the first source stage. The first switching stage (112) may be a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter. The pulse DC generator (110) may form a first decreasing section that decreases from a positive voltage (V0) to a negative first voltage (V1). The above pulse DC generator (110) can increase from a negative first voltage (V1) to a positive voltage (V0).

[0080] The step waveform generator (120) may include a second source stage (122) including a second voltage source and / or a second current source; and a second switching stage (124) that switches and outputs an output of the second source stage (122). The second switching stage (124) may be a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter.

[0081] The step waveform generator (120) can provide the first sustain section maintained at the first voltage (V1), the second decreasing section decreasing from the first voltage (V1) to the second voltage (V2), and the second sustain section maintained at the second voltage (V2).

[0082] The control unit (130) can control the pulse DC generator (110) to form the pulse DC waveform. The pulse DC waveform can be a square wave having a positive voltage (V0) and a negative first voltage (V1).

[0083] The control unit (130) can control the step waveform generator (120) to form the step waveform. The step waveform can include at least one section in which the voltage decreases. The pulse DC waveform and the step waveform can be synchronized. The step waveform can be formed only in a section in which the pulse DC waveform has a negative voltage. The step waveform of the step waveform generator (120) can be synchronized with the pulse DC waveform.

[0084] The sensor unit (140) can detect the voltage (Vo) and / or current of the output terminal of the pulse generator (100). The sensor unit (140) can detect the capacitor coupling load (Z L ) can detect the voltage (Vo) applied to the control unit (130) and provide it to the control unit (130). The control unit (130) can control the step waveform or the pulse DC waveform based on the detected voltage.

[0085] Referring to FIG. 2c, the waveform applied to the capacitor-coupled load includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first sustaining section (②) maintained at the negative first voltage (V1) for a certain period of time, a second decreasing section (③) decreasing from the first voltage (V1) to a second voltage (V2), and a second sustaining section (④) maintained at the second voltage (V2), a third decreasing section (⑤) decreasing from the second voltage (V2) to a third voltage (V3), and a third sustaining section (⑥) maintained at the third voltage (V3) for a certain period of time.

[0086] The third pulse amplitude (V0-V3) determines a relatively high ion energy by the positive voltage (V0) and the negative third voltage (V3).

[0087] The third sustain period (⑥) of the third pulse determines the peak of the incident ion flux with ion energy determined by the third pulse amplitude (V0-V3). That is, as the third sustain period (⑥) of the third pulse increases, the peak of the ion flux increases.

[0088] Accordingly, the peak energy and peak height of the ion flux are determined by the number of steps and the time of the maintenance interval.

[0089] FIG. 3 is a conceptual diagram and output waveform showing a pulse DC generator according to another embodiment of the present invention.

[0090] Referring to FIG. 3, the pulse DC generator (110) may include a first source stage (112) including a first voltage source and / or a first current source; and a first switching stage (114) that switches and outputs an output of the first source stage (112). The first switching stage (114) may be a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter. The pulse DC waveform may be a square wave having a positive voltage (V0) and a negative first voltage (V1).

[0091] Figure 4 is a conceptual diagram showing the first source stage of the pulse DC generator of Figure 3.

[0092] Referring to FIG. 4, the first source stage (112a) may be a voltage source including a capacitor (C) between a pair of output terminals. The first source stage (112b) may be a current source including an inductor (L) at a positive output terminal. The first source stage (112c) may be a current and voltage source including a capacitor (C) between a pair of output terminals and an inductor (L) and a switch (S) connected in parallel to each other at the positive output terminal.

[0093] FIG. 5 is a conceptual diagram showing a pulse DC generator according to one embodiment of the present invention.

[0094] Referring to FIG. 5, a pulse DC generator (110) may include a first source stage (112) including a first voltage source; and a first switching stage (114) that switches and outputs an output of the first source stage (112). The first switching stage (114) may be a full-bridge converter.

[0095] Figure 6a is a conceptual diagram showing a pulse DC generator according to one embodiment of the present invention.

[0096] Referring to FIG. 6A, a pulse DC generator (110) may include a first source stage (112) including a first voltage source; and a first switching stage (114) that switches and outputs an output of the first source stage (112). The first switching stage (114) may be a full-bridge converter.

[0097] Figure 6b is a conceptual diagram showing a pulse DC generator according to one embodiment of the present invention.

[0098] Referring to FIG. 6b, the pulse DC generator (110) may include a first source stage (112) including a pair of first voltage sources; and a first switching stage (114) that switches and outputs an output of the first source stage (112). The first switching stage (114) may be a three-level neutral point clamp converter (3L-NPC).

[0099] Figure 7 is a conceptual diagram showing a step waveform generator according to one embodiment of the present invention.

[0100] Referring to FIG. 7, the step waveform generator (120) may include a second source stage (122) including a second voltage source and / or a second current source; and a second switching stage (124) that switches and outputs an output of the second source stage (122). The second switching stage (124) may be a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter. For a capacitor-coupled load, the output voltage (Vs) of the step waveform generator (120) may have a step shape in which the negative voltage decreases over time.

[0101] FIG. 8 is a conceptual diagram illustrating a second source stage of a step waveform generator according to one embodiment of the present invention.

[0102] Referring to Fig. 8, the second source stage (122a) may be configured with a plurality of inductors (L1) and switches (S1) connected in series with each other. The inductors (L1) and switches (S1) connected in series with each other can provide step currents. In order to provide different step currents, the number of inductors (L1) and switches (S1) connected in series with each other may be plural. The plurality of inductors and switches connected in series with each other may be connected in parallel with each other. Accordingly, the current stored in each inductor may be transmitted to the second switching stage (124) through the switches.

[0103] Referring to FIG. 8, the second source stage (122b) may be a voltage source including a capacitor (C) between a pair of output terminals.

[0104] FIG. 9 is a conceptual diagram showing a second switching stage of a step waveform generator according to one embodiment of the present invention.

[0105] Referring to FIG. 9, the step waveform generator (120) may include a second source stage (122) including a second current source; and a second switching stage (124) that switches and outputs the output of the second source stage (122). The second switching stage (124) may be a full-bridge converter. The second current source may output a constant step current (Is).

[0106] The second switching stage (124) outputs a step current (Is) periodically over time to the capacitor coupled load (Z L ) can be applied. Accordingly, the capacitor coupling load (Z L ), the step current (Is) is expressed as a voltage (Vs) in the form of a step.

[0107] FIG. 10A and FIG. 10B are conceptual diagrams showing a second switching stage of a step waveform generator according to one embodiment of the present invention.

[0108] Referring to FIG. 10A, the step waveform generator (220) may include a plurality of sub-step waveform generators (220a to 220n). Each of the sub-step waveform generators (220a to 220n) includes a second source stage (222) including a second voltage source; and a second switching stage (224) connected to the second voltage source. The outputs of the sub-step waveform generators (220a to 220n) are connected to each other in a cascade manner.

[0109] The negative output of the first sub-step waveform generator (220a) can be connected to the positive output of the second sub-step waveform generator (220b). Additionally, the negative output of the second sub-step waveform generator (220b) can be connected to the positive output of the third sub-step waveform generator.

[0110] In order for the output voltage (Vs_DC) of the second voltage source of the first sub-step waveform generator (220a) to operate as the output voltage (Vs) of the step waveform generator (220), the second switching stage (224) may provide a current path as indicated by the red line. That is, in the second switching stage (224) of the second to nth sub-step waveform generators, the lower transistors (Q2, Q4) may be turned on, so that the voltage of the voltage source may not be applied to the output terminals of each sub-step waveform generator (220b, 220n).

[0111] Referring to FIG. 10b, in order for the output voltage (Vs_DC) of the second voltage source of the first sub-step waveform generator (220a) and the output voltage (Vs_DC) of the second voltage source of the second sub-step waveform generator (220b) to operate as the output voltage (Vs_DC X 2) of the step waveform generator (220), the second switching stage (224) may provide a current path as indicated by the red line. That is, in the second switching stage (224) of the third to nth sub-step waveform generators, the transistors (Q2, Q4) at the bottom may be turned on, so that the voltage of the voltage source may not be applied to the output terminal of each sub-step waveform generator.

[0112] FIG. 11 and FIG. 12 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0113] Referring to FIG. 11 and FIG. 12, the pulse generator (100a) is a capacitor-coupled load (Z L) provides a pulse DC waveform to the capacitor-coupled load; a step waveform generator (220) connected in parallel with the pulse DC generator (110) and provides a step waveform to the capacitor-coupled load; and a control unit (130) that controls the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. The capacitor-coupled load (Z) L ) includes a first decreasing section (①) in which the voltage decreases from a positive voltage to a negative first voltage, a first sustaining section (②) in which the voltage is maintained at the negative first voltage for a certain period of time, a second decreasing section (③) in which the voltage decreases from the first voltage to a second voltage, and a second sustaining section (④) in which the voltage is maintained at the second voltage.

[0114] The step waveform generator (220) may include a plurality of sub-step waveform generators (220a to 220n). Each of the sub-step waveform generators (220a to 220n) includes a second source stage (222) including a second voltage source; and a second switching stage (224) connected to the second voltage source. The outputs of the sub-step waveform generators (220a to 220n) are connected to each other in a cascade configuration.

[0115] The pulse DC generator (110) can output a square wave having a positive voltage (V0) and a negative first voltage (V1).

[0116] The step waveform generator (220) can output a voltage in a step form. The step waveform generator (220) can provide the first sustaining section (②) maintained at the first voltage (V1), the second decreasing section (③) decreased from the first voltage (V1) to the second voltage (V2), the second sustaining section (④) maintained at the second voltage (V2), the third decreasing section (⑤) decreased from the second voltage to a third voltage, and the third sustaining section (⑥) maintained at the third voltage. The voltage difference between the first voltage (V1) and the second voltage (V2) can be the voltage difference (Vs_DC) of the second voltage source. The voltage difference between the second voltage (V2) and the third voltage (V3) can be the voltage difference (Vs_DC) of the second voltage source. The step waveform generator (220) can provide voltage steps corresponding to the number of sub-step waveform generators.

[0117] FIGS. 13 and 14 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0118] Referring to FIGS. 13 and 14, the pulse generator (100b) is a capacitor-coupled load (Z L ) provides a pulse DC waveform to the capacitor-coupled load; a step waveform generator (320) connected in parallel with the pulse DC generator (110) and provides a step waveform to the capacitor-coupled load; and a control unit (130) that controls the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. The capacitor-coupled load (Z) L ) includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first sustaining section (②) maintained at the negative first voltage (V1) for a certain period of time, a second decreasing section (③) decreasing from the first voltage (V1) to a second voltage (V2), and a second sustaining section (④) maintained at the second voltage (V2).

[0119] The pulse DC generator (110) can output a square wave having a positive voltage (V0) and a negative first voltage (V1).

[0120] The step waveform generator (320) may include a second source stage (322) including a second current source; and a second switching stage (324) that switches and outputs the output of the second source stage (322).

[0121] The above step waveform generator (320) can output a pulse-shaped step current (Is). The pulse-shaped step current (Is) is applied to the capacitor-coupled load (Z L ) can be converted into a step-shaped voltage.

[0122] The above step waveform generator (320) is the load (Z L ) can provide a first maintenance section (②) maintained at the first voltage (V1), a second decrease section (③) decreasing from the first voltage (V1) to the second voltage (V2), a second maintenance section (④) maintained at the second voltage (V2), a third decrease section (⑤) decreasing from the second voltage to a third voltage, and a third maintenance section (⑥) maintained at the third voltage. The voltage difference between the first voltage (V1) and the second voltage (V2) may depend on the amount of charge charged to the load by the step current (Is) and the capacitance of the load. The voltage difference between the second voltage (V2) and the third voltage (V3) may depend on the amount of charge charged to the load by the step current (Is) and the capacitance of the load.

[0123] The above step waveform generator (320) can provide voltage steps corresponding to the number of step currents (Is).

[0124] FIGS. 15 and 16 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0125] Referring to FIGS. 15 and 16, the pulse generator (100c) is a capacitor-coupled load (Z L ) provides a pulse DC waveform to the capacitor-coupled load; a step waveform generator (320) connected in parallel with the pulse DC generator (410) and provides a step waveform to the capacitor-coupled load; and a control unit (130) that controls the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. The capacitor-coupled load (Z) L ) includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first sustaining section (②) maintained at the negative first voltage (V1) for a certain period of time, a second decreasing section (③) decreasing from the first voltage (V1) to a second voltage (V2), and a second sustaining section (④) maintained at the second voltage (V2).

[0126] A pulse DC generator (410) may include a first source stage (412) including a first current source; and a first switching stage (414) that switches and outputs an output of the first source stage (412). The pulse DC generator (410) may output a pulse current (Ip) in a pulse form. The pulse current (Ip) in a pulse form is applied to the capacitor coupling load (Z). L ) can be converted into a voltage (Vp) in the form of a square wave. The voltage difference between the positive voltage (V0) and the first voltage (V1) may depend on the amount of charge charged to the load by the pulse current (Ip) and the capacitance of the load.

[0127] The step waveform generator (320) may include a second source stage (322) including a second current source; and a second switching stage (324) that switches and outputs the output of the second source stage (322). The step waveform generator (320) may output a pulse-shaped step current (Is). The pulse-shaped step current (Is) may be applied to the capacitor-coupled load (Z). L ) can be converted into a step-type voltage (Vs).

[0128] The above step waveform generator (320) is the load (Z L ) can provide a first maintenance section (②) maintained at the first voltage (V1), a second decrease section (③) decreasing from the first voltage (V1) to the second voltage (V2), a second maintenance section (④) maintained at the second voltage (V2), a third decrease section (⑤) decreasing from the second voltage to a third voltage, and a third maintenance section (⑥) maintained at the third voltage. The voltage difference between the first voltage (V1) and the second voltage (V2) may depend on the amount of charge charged to the load by the step current (Is) and the capacitance of the load. The voltage difference between the second voltage (V2) and the third voltage (V3) may depend on the amount of charge charged to the load by the step current (Is) and the capacitance of the load.

[0129] Each switching element can have inherently unique physical characteristics that can be easily predicted during practical implementation. These physical characteristics may include on-off delay time, rise and fall times, circuit connection characteristics, and load characteristics. Circuit connection characteristics may include parasitic inductance, parasitic capacitance, and parasitic resistance.

[0130] Considering the inherent physical properties, time-varying potential characteristics can exist during the transition from a positive to a negative potential (①) and the transition from a negative potential to a lower negative potential (③). The ion energy distribution due to this time-varying characteristic can appear differently, and this can be controlled to obtain the desired ion energy distribution.

[0131] FIG. 17 and FIG. 18 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0132] Referring to FIG. 17 and FIG. 18, the pulse generator (100d) is a capacitor-coupled load (Z L ) provides a pulse DC waveform to the capacitor-coupled load; a step waveform generator (320) connected in parallel with the pulse DC generator (110) and provides a step waveform to the capacitor-coupled load; and a control unit (130) that controls the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. The capacitor-coupled load (Z) L ) includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first sustaining section (②) maintained at the negative first voltage (V1) for a certain period of time, a second decreasing section (③) decreasing from the first voltage (V1) to a second voltage (V2), and a second sustaining section (④) maintained at the second voltage (V3).

[0133] The pulse DC generator (110) can output a square wave having a positive voltage (V0) and a negative first voltage (V1).

[0134] The step waveform generator (320) may include a second source stage (322) including a second current source; and a second switching stage (324) that switches and outputs the output of the second source stage (322).

[0135] The above step waveform generator (320) can output a pulse-shaped step current (Iso). The pulse-shaped step current (Is0) is applied to the capacitor-coupled load (Z L ) can be converted into a step-type voltage (Vs).

[0136] The above step waveform generator (320) is the load (Z L ) can provide the first maintenance section (②) maintained at the first voltage (V1), the second decreasing section (③) decreased from the first voltage (V1) to the second voltage (V2), and the second maintaining section (④) maintained at the second voltage (V2). The voltage difference between the first voltage (V1) and the second voltage (V2) can depend on the amount of charge charged to the load by the step current (Iso) and the capacitance of the load.

[0137] In the second decreasing section (③) where the first voltage (V1) decreases to the second voltage (V2), the step current (Iso) can be maintained for a certain period of time. The step voltage waveform (Vs) by the step current (Iso) can have a predetermined slope. Accordingly, an ion flux having an intermediate energy between the first ion energy corresponding to the first voltage (V1) and the second ion energy corresponding to the second voltage (V2) can be provided by the slope of the step voltage (Vs). That is, the ion flux can have a predetermined energy range.

[0138] FIGS. 19 and 20 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0139] Referring to FIGS. 19 and 20, the pulse generator (500) is a capacitor-coupled load (Z L) provides a pulse DC waveform to the capacitor-coupled load; a step waveform generator (520) provides a step waveform to the capacitor-coupled load and is connected in parallel with the pulse DC generator (510); and a control unit (130) controls the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. The capacitor-coupled load (Z) L ) includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first sustaining section (②) maintained at the negative first voltage (V1) for a certain period of time, a second decreasing section (③) decreasing from the first voltage (V1) to a second voltage (V2), and a second sustaining section (④) maintained at the second voltage (V2).

[0140] The pulse DC generator (510) may include a plurality of sub-pulse DC generators (510a, 510b). Each of the sub-pulse DC generators (510a, 510b) includes a second source stage (512) including a first voltage source; and a second switching stage (514) connected to the second voltage source. The outputs of the sub-pulse DC generators (510a, 510b) are connected to each other in a cascade configuration.

[0141] The pulse DC generator (510) can output a square wave having a positive voltage (V0) and a negative first voltage (V1).

[0142] The step waveform generator (520) can form a step-shaped voltage (Vs) to the capacitor-coupled load. The step waveform generator (520) can provide the first sustaining section (②) maintained at the first voltage (V1), the second decreasing section (③) decreasing from the first voltage (V1) to the second voltage (V2), the second sustaining section (④) maintained at the second voltage (V2), the third decreasing section (⑤) decreasing from the second voltage (V2) to a third voltage (V3), and the third sustaining section (⑥) maintained at the third voltage.

[0143] The step waveform generator (520) may include a plurality of sub-step waveform generators (520a, 520b). Each of the sub-step waveform generators (520a, 520b) includes a second source stage (522) including a second current source; and a second switching stage (524) connected to the second current source. The outputs of the sub-step waveform generators (520a, 520b) are connected in parallel with each other. The first sub-step waveform generator (520a) may output a first step current (Is1). The second sub-step waveform generator (520b) may output a second step current (Is2).

[0144] In the second decreasing section (③) where the first voltage (V1) decreases to the second voltage (V2), the first step current (Is1) can be maintained for a certain period of time. Accordingly, the step voltage by the first step current (Is1) can have a predetermined slope. Accordingly, an ion flux having a first intermediate energy between the first ion energy corresponding to the first voltage (V1) and the second ion energy corresponding to the second voltage (V2) can be provided by the slope of the step voltage.

[0145] In the third decreasing section (⑤) where the second voltage (V2) decreases to the third voltage (V3), the second step current (Is2) can be maintained for a certain period of time. Accordingly, the step voltage by the second step current (Is2) can have a predetermined slope. Accordingly, an ion flux having a second intermediate energy between the second ion energy corresponding to the second voltage (V2) and the third ion energy corresponding to the third voltage (V3) can be provided by the slope of the step voltage. That is, the ion flux can have a predetermined energy range.

[0146] FIG. 21 and FIG. 22 are drawings illustrating a pulse generating device according to another embodiment of the present invention.

[0147] Referring to FIGS. 21 and 22, the pulse generator (600) is a capacitor-coupled load (Z L ) provides a pulse DC waveform to the capacitor-coupled load; a step waveform generator (620) provides a step waveform to the capacitor-coupled load and is connected in parallel with the pulse DC generator (610); and a control unit (130) controls the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator. The capacitor-coupled load (Z) L ) includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first sustaining section (②) maintained at the negative first voltage (V1) for a certain period of time, a second decreasing section (③) decreasing from the first voltage (V1) to a second voltage (V2), and a second sustaining section (④) maintained at the second voltage (V2).

[0148] A pulse DC generator (610) generates a square wave having a positive voltage (V0) and a negative first voltage (V1) to the capacitor-coupled load (Z). L) can be formed. The pulse DC generator (610) may include a first source stage (612) including a first current source; and a first switching stage (614) that switches and outputs the output of the first source stage (612). The pulse DC generator (610) may output a pulse current (Ipo) in a pulse form for a certain period of time. The pulse current (Ipo) in a pulse form may be outputted to the capacitor coupling load (Z L ) can be converted into a voltage (Vp) in the form of a square wave. The voltage difference between the positive voltage (V0) and the first voltage (V1) may depend on the amount of charge charged to the load by the pulse current (Ipo) and the capacitance of the load. The amplitude and duration of the pulse current (Ipo) may provide a slope of the pulse voltage (Vp). The first slope (a), the second slope (b), and the third slope (c) may be determined by different amplitudes and durations of the pulse currents (Ipo). The slope of the pulse voltage (Vp) may provide an offset between the first ion energy corresponding to the first voltage (V1) at zero ion energy. The offset may depend on the duration (t1, t2, t3) of the slope. The slope of the pulse voltage (Vp) may depend on the electrical characteristics of the pulse DC generator (610).

[0149] The step waveform generator (620) may include a second source stage (622) including a second current source; and a second switching stage (624) that switches and outputs the output of the second source stage (622).

[0150] The above step waveform generator (620) can output a step current (Iso) in a pulse form. The step current (Iso) in a pulse form is output by the capacitor coupling load (Z L ) can be converted into a step-type voltage (Vs).

[0151] The above step waveform generator (320) is the load (ZL ) can provide the first maintenance section (②) maintained at the first voltage (V1), the second decreasing section (③) decreased from the first voltage (V1) to the second voltage (V2), and the second maintaining section (④) maintained at the second voltage (V2). The voltage difference between the first voltage (V1) and the second voltage (V2) can depend on the amount of charge charged to the load by the step current (Iso) and the capacitance of the load.

[0152] In the second decreasing section (③) where the first voltage (V1) decreases to the second voltage (V2), the step current (Iso) can be maintained for a certain period of time. Accordingly, the step voltage waveform by the step current (Iso) can have a predetermined slope (a', b', c'). Accordingly, an ion flux having an intermediate energy between the first ion energy corresponding to the first voltage (V1) and the second ion energy corresponding to the second voltage (V2) can be provided by the slope (a', b', c') of the step voltage. That is, the ion flux can have a predetermined energy range.

[0153] Figure 23 is a flowchart explaining an operating method of a pulse generating device according to one embodiment of the present invention.

[0154] Referring to Fig. 23, the operating method of the pulse generator includes the steps of setting a pulse DC voltage waveform and setting a step voltage waveform (S110); operating the pulse DC generator (110) to generate a capacitor-coupled load (Z L ) to apply a pulse DC voltage waveform (Vp) (S120); and operate the step waveform generator (120) to generate the capacitor-coupled load (Z L ) includes a step (S120) of applying a step voltage waveform (Vs);

[0155] The above pulse DC generator (110) is operated to generate a capacitor-coupled load (Z L) in which a pulse DC voltage waveform (Vp) is applied (S120), the voltage of the capacitor-coupled load can be measured with a voltage sensor to control the current or voltage until the set pulse DC voltage waveform is reached (S122, S123, S124).

[0156] The step waveform generator (120) is operated to generate the capacitor-coupled load (Z L ) in which a step waveform voltage is applied (S130), the voltage of the capacitor-coupled load can be measured with a voltage sensor to control the current or voltage until the set step voltage waveform (Vs) is reached (S131, S132, S133, S134).

[0157] Fig. 24 is a conceptual diagram illustrating a pulse generating device according to another embodiment of the present invention.

[0158] Fig. 25 is a circuit diagram illustrating a pulse DC generator and a step waveform generator of the pulse generator of Fig. 24.

[0159] Fig. 26 is a timing diagram showing the waveform applied to the load of the pulse generator of Fig. 24.

[0160] Figures 27 and 28 are drawings showing the current paths of the pulse DC generator and step waveform generator of Figure 25.

[0161] Referring to FIGS. 24 to 27, a pulse generating device according to one embodiment of the present invention is a capacitor-coupled load (Z L ) pulse DC generator (710) providing a pulse DC waveform to the capacitor-coupled load (Z); L ) and a step waveform generator (720) connected in parallel with the pulse DC generator; a switching unit (750) for switching the outputs of the pulse DC generator and the step waveform generator; and a control unit (130) for controlling the pulse DC generator (710) and the step waveform generator (720).

[0162] The waveform applied to the above-mentioned capacitor-coupled load includes a first decreasing section (①) decreasing from a positive voltage (V0) to a negative first voltage (V1), a first maintaining section (②) maintained at the negative first voltage for a certain period of time, a second decreasing section (③) decreasing from the first voltage to a second voltage, and a second maintaining section (④) maintained at the second voltage.

[0163] The pulse DC generator (710) is branched from the output terminal of the current source rectifier (705) and connected to one end of the first inductor (712) to generate a pulse current (Ip). The step waveform generator (720) is branched from the output terminal of the current source rectifier (705) and connected to one end of the second inductor (722) to generate a step current (Is).

[0164] The pulse DC generator (710) includes a first transistor (Q1) having a source connected to the other end of the first inductor (712); a second transistor (Q2) having a source connected to the other end of the first inductor (712); and a first diode (D1) connected in series to a drain of the first transistor (Q1). The first diode (D1) is connected to one end of the first inductor (712), and the drain of the second transistor (Q2) is connected to an input terminal of the switching unit (750).

[0165] The step waveform generator (720) includes a third transistor (Q3) having a source connected to the other end of the second inductor (722); a fourth transistor (Q4) having a source connected to the other end of the second inductor (722); and a second diode (D2) connected in series to the drain of the third transistor. The second diode (D2) is connected to one end of the second inductor (722). The drain of the fourth transistor is connected to the input terminal of the switching unit.

[0166] The above switch unit (750) includes a fifth transistor (Q5) connected to an output terminal of the pulse DC generator (710); a sixth transistor (Q6) connected in series with the fifth transistor (Q5); a seventh transistor (Q7) connected to an output terminal of the pulse DC generator (710); an eighth transistor (Q8) connected in series with the seventh transistor (Q7); a first inverter diode (ID1) disposed between the fifth transistor (Q5) and an output terminal of the pulse DC generator (710); a second inverter diode (ID2) disposed between the fifth transistor (Q5) and the sixth transistor (Q6); a third inverter diode (ID3) disposed between the seventh transistor (Q7) and an output terminal of the pulse DC generator (710); and a fourth inverter diode (ID4) disposed between the seventh transistor (Q7) and the eighth transistor (Q8).

[0167] The contact between the fifth transistor (Q5) and the second diode (ID2) is connected to the load (Z L ) is connected to one end of the load (Z). The contact point between the seventh transistor (Q7) and the fourth diode (ID4) is connected to the load (Z L ) is connected to the other end.

[0168] A three-phase power supply can be connected to a current source rectifier (705). The three-phase power supply can have a first terminal (Va), a second terminal (Vb), and a third terminal (Vc) with a phase difference of 120 degrees.

[0169] The current source rectifier (705) may include a first diode (CD1), a first control switch (TR1), a second diode (CD2), and a second control switch (TR2) that are sequentially connected in series. The first terminal (Va) may be connected between the first control switch (TR1) and the second diode (CD2).

[0170] The current source rectifier (705) may include a third diode (CD3), a third control switch (TR3), a fourth diode (CD4), and a fourth control switch (TR4) that are sequentially connected in series. The second terminal (Vb) may be connected between the third control switch (TR3) and the fourth diode (CD4).

[0171] The current source rectifier (705) may include a fifth diode (CD5), a fifth control switch (TR5), a sixth diode (CD6), and a seventh control switch (TR6) that are sequentially connected in series. The third terminal (Vc) may be connected between the fifth control switch (TR5) and the sixth diode (CD6).

[0172] The first diode (CD1), the third diode (CD3), and the fifth diode (CD5) can be connected to each other to provide a first output terminal.

[0173] The second control switch (TR2), the fourth control switch (TR4), and the sixth control switch (TR6) may be connected to each other to provide a second output terminal. The first to sixth control switches (TR1 to TR6) may be transistors.

[0174] The control unit (130) can control the path of the pulse current (Ip) in the first reduction section (①). The pulse current (Ip) is controlled by the first inductor (712), the second transistor (Q2), the third inverter diode (ID3), the seventh transistor (Q7), and the load (Z). L ), can flow through the path of the second inverter diode (ID2) and the sixth transistor (Q6).

[0175] The above control unit (130) can control the path of the step current (Is) in the second reduction section (③). The step current (Is) can flow through the path of the second inductor (722), the fourth transistor (Q4), the third inverter diode (ID3), the seventh transistor (Q7), the load (190), the second inverter diode (ID2), and the sixth transistor (Q6).

[0176] When the pulse current (Ip) does not flow to the switching unit (750), the pulse current (Ip) flows to the first inductor (712) and the first transistor (Q1) to form a closed loop and can operate in a free-wheeling mode.

[0177] When the step current (Is) does not flow to the switching unit (750), the step current (Is) flows to the second inductor (722) and the second transistor (Q13) to form a closed loop and can operate in a free-wheeling mode.

[0178] Although the present invention has been illustrated and described with respect to preferred embodiments of the features, the present invention is not limited to these embodiments, and includes various forms of embodiments that can be implemented by a person having ordinary skill in the art to which the invention pertains without departing from the technical spirit of the present invention claimed in the claims.

[0179] Description of the symbol

[0180] 100: Pulse generator

[0181] 110: Pulse DC generator

[0182] 120: Step Waveform Generator

[0183] 130: Control unit

Claims

1. A pulse DC generator that provides a pulse DC waveform to a capacitor-coupled load; A step waveform generator providing a step waveform to the above-mentioned capacitor-coupled load and connected in parallel with the pulse DC generator; and A control unit for controlling the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator is included, A pulse generator, characterized in that the waveform applied to the capacitor-coupled load includes a first decreasing section decreasing from a positive voltage to a negative first voltage, a first holding section maintained at the negative first voltage for a certain period of time, a second decreasing section decreasing from the first voltage to a second voltage, and a second holding section maintained at the second voltage.

2. In paragraph 1, The above pulse DC generator: A first source stage comprising at least one of a first voltage source and a first current source; and A pulse generator comprising a first switching stage that switches and outputs the output of the first source stage.

3. In paragraph 2, A pulse generator characterized in that the first switching stage is a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter.

4. In paragraph 1, The above step waveform generator: a second source stage comprising at least one of a second voltage source and a second current source; and A pulse generator comprising a second switching stage that switches and outputs the output of the second source stage.

5. In paragraph 4, A pulse generator characterized in that the second switching stage is a half-bridge converter, a full-bridge converter, a three-level neutral point clamped converter (3L-NPC), a three-level active neutral point clamped converter (3L-ANPC), or a multi-level converter.

6. In paragraph 1, The pulse DC generator forms a first decreasing section decreasing from a positive voltage to a negative first voltage in the capacitor-coupled load, A pulse generator characterized in that the step waveform generator provides the capacitor-coupled load with the first sustain period maintained at the first voltage, the second decreasing period reduced from the first voltage to the second voltage, and the second sustain period maintained at the second voltage.

7. In paragraph 4, The second current source provides a step current, A pulse generator characterized in that the second switching stage provides the step current to the capacitor-coupled load in the second reduction section.

8. In paragraph 7, The above step current forms a slope waveform in the above capacitor coupled load, A pulse generator characterized in that the above ramp waveform provides an ion flux between a first energy peak caused by the first voltage and a second energy peak caused by the second voltage.

9. In paragraph 1, The step waveform generator comprises a plurality of sub-step waveform generators, Each of the above sub-step waveform generators: a second source stage including a second voltage source; and A second switching stage connected to the second voltage source is included, A pulse generator characterized in that the outputs of the above sub-step waveform generators are connected to each other in a cascade form.

10. In paragraph 1, The above pulse DC waveform generator comprises a plurality of sub-pulse DC waveform generators, Each of the above sub-pulse DC waveform generators: a first source stage including a first voltage source; and comprising a first switching stage connected to the first voltage source; A pulse generator, characterized in that the outputs of the above sub-pulse DC waveform generators are connected to each other in a cascade form.

11. In paragraph 1, The step waveform generator comprises a plurality of sub-step waveform generators, Each of the above sub-step waveform generators: a second source stage including a second current source; and comprising a second switching stage connected to the second current source; A pulse generator, characterized in that the outputs of the above sub-step waveform generators are connected in parallel with each other.

12. In paragraph 11, The second switching stage is: A first transistor and a second transistor connected in parallel to the output terminal of the second current source; a first diode connected between the first transistor and ground; and including a second diode connected in series with the second transistor, A pulse generator, characterized in that the output of the second switching stage is provided through the second transistor and the second diode.

13. In paragraph 12, The step waveform generator comprises a first sub-step waveform generator and a second sub-step waveform generator, The first sub-step waveform generator provides a first step current, A pulse generator, characterized in that the second sub-step waveform generator provides a second step current different from the first step current.

14. In paragraph 13, The first step current forms a first ramp waveform in the capacitor coupling load, A pulse generator characterized in that the second step current forms a second slope waveform in the capacitor coupling load.

15. In paragraph 1, The above pulse DC generator: a first source stage including a first current source; and It includes a first switching stage that switches and outputs the output of the first source stage, The above step waveform generator: a second source stage including a second current source; and A pulse generator comprising a second switching stage that switches and outputs the output of the second source stage.

16. In paragraph 15, The above pulse DC generator provides a pulse current, A pulse generator characterized in that it controls the ion flux according to the ion energy by controlling the application time of the pulse current.

17. In paragraph 15, The above step waveform generator provides a step current, A pulse generator characterized in that it controls the ion flux according to the ion energy by controlling the application time of the above step current.

18. In paragraph 1, A pulse generator, characterized in that the waveform applied to the above-mentioned capacitor-coupled load further includes a third decreasing section decreasing from the second voltage to a third voltage, and a third maintaining section maintained at the third voltage for a certain period of time.

19. A pulse DC generator providing a pulse DC waveform to a capacitor-coupled load; a step waveform generator providing a step waveform to the capacitor-coupled load and connected in parallel with the pulse DC generator; and a control unit controlling the pulse DC waveform of the pulse DC generator and the step waveform of the step waveform generator, wherein the waveform applied to the capacitor-coupled load includes a first decreasing section decreasing from a positive voltage to a negative first voltage, a first sustaining section maintained at the negative first voltage for a predetermined time, a second decreasing section decreasing from the first voltage to a second voltage, and a second sustaining section maintained at the second voltage. In this method of operating a pulse generator, A step of setting the pulse DC waveform and the step waveform; A step of operating the pulse DC generator to form the pulse DC waveform in the capacitor-coupled load; and A step of operating the step waveform generator to form the step waveform in the capacitor-coupled load, The pulse DC waveform includes a first decreasing section decreasing from the positive voltage to the negative first voltage, A method of operating a pulse generator, characterized in that the step waveform includes a first holding period in which the first voltage is maintained at a negative level for a certain period of time, a second decreasing period in which the first voltage is decreased to a second voltage, and a second holding period in which the second voltage is maintained.

20. A pulse DC generator that provides a pulse DC waveform to a capacitor-coupled load; A step waveform generator providing a step waveform to the above capacitor-coupled load and connected in parallel with the pulse DC generator; A switching unit that switches the outputs of the pulse DC generator and the step waveform generator; and It includes a control unit that controls the pulse DC generator and the step waveform, A pulse generator, characterized in that the waveform applied to the capacitor-coupled load includes a first decreasing section decreasing from a positive voltage to a negative first voltage, a first holding section maintained at the negative first voltage for a certain period of time, a second decreasing section decreasing from the first voltage to a second voltage, and a second holding section maintained at the second voltage.

21. In paragraph 20, The above pulse DC generator is branched from the output terminal of the current source rectifier and connected to one end of the first inductor to generate a pulse current (Ip), A pulse generator characterized in that the step waveform generator is branched from the output terminal of the current source rectifier and connected to one end of a second inductor and generates a step current (Is).

22. In paragraph 21, The above pulse DC generator: A first transistor having a source connected to the other terminal of the first inductor; A second transistor having a source connected to the other end of the first inductor; and a first diode connected in series to the drain of the first transistor; The above first diode is connected to one end of the above first inductor, A pulse generating device characterized in that the drain of the second transistor is connected to the input terminal of the switching unit.

23. In paragraph 21, The above step waveform generator: A third transistor having a source connected to the other terminal of the second inductor; A fourth transistor, the source of which is connected to the other end of the second inductor; and a second diode connected in series to the drain of the third transistor; The second diode is connected to one end of the second inductor, A pulse generating device characterized in that the drain of the fourth transistor is connected to the input terminal of the switching unit.

24. In paragraph 21, The above switch part: A fifth transistor connected to the output terminal of the pulse DC generator; A sixth transistor connected in series with the fifth transistor; A seventh transistor connected to the output terminal of the pulse DC generator; An eighth transistor connected in series with the seventh transistor; A first inverter diode disposed between the fifth transistor and the output terminal of the pulse DC generator; A second inverter diode disposed between the fifth transistor and the sixth transistor; A third inverter diode arranged between the seventh transistor and the output terminal of the pulse DC generator; and a fourth inverter diode disposed between the seventh transistor and the eighth transistor; The contact between the fifth transistor and the second diode is connected to one end of the load, A pulse generator, characterized in that the contact between the seventh transistor and the fourth diode is connected to the other end of the load.

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