Plasma processing method and plasma processing apparatus

Abstract

A plasma processing method according to the present disclosure includes a process of arranging a substrate on a substrate support, a process of supplying a processing gas for processing the substrate into a chamber, a process of generating plasma of the processing gas in the chamber by a first high-frequency signal and a second high-frequency signal, and a process of applying a bias signal to the substrate support, the process of generating the plasma including a process of superimposing the second high-frequency signal on the first high-frequency signal based on a timing of the bias signal applied to the substrate support.

Description

Technical Field

[0001] Exemplary embodiments of this disclosure relate to plasma processing methods and plasma processing apparatus. Background Technology

[0002] As a technique for controlling the quantity and quality of free radicals and ions, there exists a plasma processing device described in Patent Document 1.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-4710 Summary of the Invention

[0006] This disclosure provides a technique for reducing the effects of high-frequency reflections.

[0007] In one exemplary embodiment of this disclosure, a plasma processing method is provided, in which a substrate is subjected to plasma processing in a plasma processing apparatus. The plasma processing apparatus includes: a chamber; and a substrate support disposed within the chamber and configured to support the substrate. The plasma processing method includes: a step of placing the substrate on the substrate support; a step of supplying a processing gas for processing the substrate into the chamber; a step of generating plasma of the processing gas in the chamber using a first high-frequency signal and a second high-frequency signal; and a step of supplying a bias signal to the substrate support, wherein the step of generating the plasma includes a step of superimposing the second high-frequency signal with the first high-frequency signal based on the timing of the bias signal being supplied to the substrate support.

[0008] In one exemplary embodiment of this disclosure, a plasma processing apparatus is provided. The plasma processing apparatus includes: a chamber; a substrate support disposed within the chamber and configured to support the substrate; and a control unit that performs the following control: disposing of the substrate on the substrate support; supplying a processing gas for processing the substrate into the chamber; generating plasma of the processing gas in the chamber using a first high-frequency signal and a second high-frequency signal; supplying a bias signal to the substrate support; and superimposing the second high-frequency signal with the first high-frequency signal based on the timing of the bias signal being supplied to the substrate support.

[0009] Invention Effects

[0010] According to an exemplary embodiment of this disclosure, a technique capable of reducing the effects of high-frequency reflections can be provided. Attached Figure Description

[0011] Figure 1This is a schematic diagram illustrating a substrate processing apparatus 1 according to an exemplary embodiment.

[0012] Figure 2 This is a partial enlarged view showing an example of the substrate support section 11 included in the substrate processing apparatus 1.

[0013] Figure 3 This is a flowchart illustrating an example of a plasma processing method according to an exemplary embodiment.

[0014] Figure 4 This is a timing diagram illustrating an example of the source RF signals and bias signals in this processing method.

[0015] Figure 5A This is a diagram illustrating an example of the electrical pulse P1 contained in the bias DC signal.

[0016] Figure 5B This is a diagram illustrating an example of the electrical pulse P1 contained in the bias DC signal.

[0017] Figure 5C This is a diagram illustrating an example of the electrical pulse P1 contained in the bias radio frequency signal.

[0018] Figure 6 This is a diagram illustrating an example of the electrical pulse P2 contained in the second source radio frequency signal.

[0019] Figure 7 This is a diagram illustrating an example of an electrical pulse P3 contained in a third-source radio frequency signal.

[0020] Figure 8 This is a timing diagram representing other examples of this processing method.

[0021] Figure 9 This is a timing diagram representing other examples of this processing method.

[0022] Figure 10 This is a timing diagram representing other examples of this processing method.

[0023] Figure 11 This is a timing diagram representing other examples of this processing method.

[0024] Figure 12 This is a timing diagram representing other examples of this processing method.

[0025] Figure 13 This is a timing diagram representing other examples of this processing method.

[0026] Figure 14 This is a timing diagram representing other examples of this processing method.

[0027] Figure 15This is a timing diagram representing other examples of this processing method.

[0028] Figure 16 This is a timing diagram representing other examples of this processing method.

[0029] Figure 17 This is a timing diagram representing other examples of this processing method.

[0030] Figure 18 This is a timing diagram representing other examples of this processing method.

[0031] Figure 19 This is a timing diagram representing other examples of this processing method.

[0032] Figure 20 This is a timing diagram representing other examples of this processing method.

[0033] Figure 21 This is a timing diagram representing other examples of this processing method.

[0034] Figure 22 This is a timing diagram representing other examples of this processing method.

[0035] Figure 23 This is a timing diagram representing other examples of this processing method.

[0036] Figure 24 This is a timing diagram representing other examples of this processing method.

[0037] Figure 25 This is a timing diagram representing other examples of this processing method. Detailed Implementation

[0038] The following describes various embodiments of this disclosure.

[0039] In one exemplary embodiment, a plasma processing method is provided, in which a substrate is subjected to plasma processing in a plasma processing apparatus. The plasma processing apparatus includes: a chamber; and a substrate support disposed within the chamber and configured to support the substrate. The plasma processing method includes: a step of placing the substrate on the substrate support; a step of supplying a processing gas for processing the substrate into the chamber; a step of generating plasma of the processing gas in the chamber using a first high-frequency signal and a second high-frequency signal; and a step of supplying a bias signal to the substrate support, wherein the step of generating the plasma includes a step of superimposing the second high-frequency signal and the first high-frequency signal based on the timing of the bias signal being applied to the substrate support.

[0040] In one exemplary embodiment, the bias signal is a pulse wave that periodically includes a first electrical pulse, the first high-frequency signal is a high-frequency continuous wave having a first frequency, and the second high-frequency signal is a pulse wave that periodically includes a second electrical pulse, wherein the second electrical pulse includes a high frequency having a second frequency different from the first frequency.

[0041] In one exemplary embodiment, the first electrical pulse comprises one or more pulse voltages.

[0042] In one exemplary embodiment, the first electrical pulse is constituted by a high-frequency continuous wave.

[0043] In one exemplary embodiment, the first period of the cycle in the bias signal that is the period in which the first electrical pulse repeats is equal to the second period of the cycle in the second high-frequency signal that is the period in which the second electrical pulse repeats.

[0044] In one exemplary embodiment, during the plasma generation process, a first high-frequency signal and a second high-frequency signal are supplied to the substrate support.

[0045] In one exemplary embodiment, the timing of the second electrical pulse occurrence is equal to the timing of the first electrical pulse termination.

[0046] In one exemplary embodiment, the second electrical pulse occurs earlier than the first electrical pulse stops.

[0047] In one exemplary embodiment, the timing of the second electrical pulse is later than the timing of the first electrical pulse stopping.

[0048] In one exemplary embodiment, the period during which the second electrical pulse stops in the second cycle is equal to the period during which the first electrical pulse occurs in the first cycle.

[0049] In one exemplary embodiment, the period during which the second electrical pulse stops in the second cycle is longer than the period during which the first electrical pulse occurs in the first cycle.

[0050] In one exemplary embodiment, the period during which the second electrical pulse stops in the second cycle is shorter than the period during which the first electrical pulse occurs in the first cycle.

[0051] In one exemplary embodiment, the timing of the second electrical pulse occurrence is equal to the timing of the start of the first electrical pulse.

[0052] In one exemplary embodiment, the second electrical pulse occurs earlier than the first electrical pulse.

[0053] In one exemplary embodiment, the timing of the second electrical pulse is later than the timing of the start of the first electrical pulse.

[0054] In one exemplary embodiment, the period during which the second electrical pulse is supplied in the second cycle is equal to the period during which the first electrical pulse occurs in the first cycle.

[0055] In one exemplary embodiment, the period during which the second electrical pulse is supplied in the second cycle is longer than the period during which the first electrical pulse occurs in the first cycle.

[0056] In one exemplary embodiment, the period during which the second electrical pulse is supplied in the second cycle is shorter than the period during which the first electrical pulse occurs in the first cycle.

[0057] In one exemplary embodiment, the plasma generation process includes a process of further superimposing a third high-frequency signal with a first high-frequency signal based on the timing of the bias signal supplied to the substrate support.

[0058] In one exemplary embodiment, the third high-frequency signal is a pulse wave that periodically includes a third electrical pulse. The third electrical pulse is composed of a high frequency having a third frequency that is different from the first frequency and the second frequency. At least a portion of the third electrical pulse is superimposed on the second electrical pulse in time and superimposed on the first high-frequency signal.

[0059] In one exemplary embodiment, the third high-frequency signal is a pulse wave that periodically includes a third electrical pulse. The third electrical pulse is composed of a high frequency having a third frequency that is different from the first frequency and the second frequency. The third electrical pulse does not superimpose with the second electrical pulse in time, but is superimposed with the first high-frequency signal.

[0060] In one exemplary embodiment, the second frequency is an integer multiple of the first frequency.

[0061] In one exemplary implementation, the pulse voltage includes a negative voltage.

[0062] In one exemplary embodiment of this disclosure, a plasma processing apparatus is provided. The plasma processing apparatus includes: a chamber; a substrate support disposed within the chamber and configured to support the substrate; and a control unit that performs the following control: disposing of the substrate on the substrate support; supplying a processing gas for processing the substrate into the chamber; generating plasma of the processing gas in the chamber using a first high-frequency signal and a second high-frequency signal; applying a bias signal to the substrate support; and superimposing the second high-frequency signal with the first high-frequency signal based on the timing of applying the bias signal to the substrate support.

[0063] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, the same or identical elements will be labeled with the same reference numerals in the drawings, and repeated descriptions will be omitted. Unless otherwise specified, positional relationships such as up, down, left, and right will be described based on the positional relationships shown in the drawings. The dimensions in the drawings are not actual scales, and the actual scale is not limited to the scale shown.

[0064] Figure 1 This diagram schematically illustrates a substrate processing apparatus 1 according to an exemplary embodiment. The substrate processing apparatus 1 is a capacitively coupled plasma processing apparatus. The substrate processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, an exhaust system 40, and a control unit 50. Furthermore, the substrate processing apparatus 1 includes a substrate support unit 11 and a gas inlet unit. The gas inlet unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet unit includes a nozzle 13. The substrate support unit 11 is disposed within the plasma processing chamber 10. The nozzle 13 is disposed above the substrate support unit 11. In one exemplary embodiment, the nozzle 13 constitutes at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the nozzle 13, the sidewall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas outlet for discharging gas from the plasma processing space. The frame 10a is grounded. The nozzle 13 and the substrate support 11 are electrically insulated from the frame of the plasma processing chamber 10.

[0065] Figure 2This is a partially enlarged view showing an example of a substrate support portion 11 included in a substrate processing apparatus 1. The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 includes a base 113, an electrostatic chuck 114, and an electrode plate 117. Furthermore, the main body portion 111 has a central region (substrate support surface) 111a for supporting a substrate (wafer) W and an annular region (annular support surface) 111b for supporting the ring assembly 112. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a top view. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 in such a way that it surrounds the substrate W on the central region 111a of the main body portion 111. The base 113 may include conductive components. The conductive components of the base 113 can function as a lower electrode. An electrostatic chuck 114 is disposed on a base. The upper surface of the electrostatic chuck 114 has a substrate support surface 111a. The ring assembly 112 includes one or more annular components. At least one of the one or more annular components is an edge ring.

[0066] The electrostatic chuck 114 internally includes a chuck electrode 115 and a bias electrode 116. The chuck electrode 115 has an electrode 115a disposed between the substrate support surface 111a and the base 113. The electrode 115a can be a planar electrode corresponding to the shape of the substrate support surface 111a. Furthermore, the chuck electrode 115 can have electrodes 115b and 115c disposed between the ring assembly 112 and the base 113. Electrodes 115b and 115c can be annular electrodes corresponding to the shape of the ring assembly 112. Additionally, electrode 115c is disposed outside electrode 115b. The bias electrode 116 has an electrode 116a disposed between electrode 115a (or substrate support surface 111a) and the base 113. Electrode 116a can be a planar electrode corresponding to the shape of the substrate support surface 111a and / or electrode 115a. Furthermore, the bias electrode 116 can have an electrode 116b disposed between the ring assembly and the base 113.

[0067] Furthermore, when the conductive component included in the base 113 functions as the lower electrode, the electrostatic chuck 114 may not include the bias electrode 116. Additionally, the chuck electrode 115 may also function as the lower electrode. When the chuck electrode 115 functions as the lower electrode, the electrostatic chuck 114 may not include the bias electrode 116. Furthermore, the electrostatic chuck 114 may be configured as a separate component comprising the portion including electrodes 115a and 116a, and the portion including electrodes 115b, 115c, and 116b.

[0068] Furthermore, although not shown in the figures, the substrate support 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck 114, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path, or a combination thereof. In the flow path, a heat transfer fluid such as brine or gas flows. Additionally, the substrate support 11 may include a heat transfer gas supply section configured to supply heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0069] Return to Figure 1 The nozzle 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The nozzle 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlets 13c. The processing gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s through the gas diffusion chamber 13b and the plurality of gas inlets 13c. Furthermore, the nozzle 13 includes a conductive component. The conductive component of the nozzle 13 functions as an upper electrode. In addition to the nozzle 13, the gas inlet may also include one or more side gas injectors (SGIs) mounted on one or more openings formed on the frame 10a.

[0070] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one exemplary embodiment, the gas supply unit 20 is configured to supply at least one processing gas from each corresponding gas source 21 to the nozzle 13 via each corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include one or more flow modulation devices for modulating or pulsedizing the flow rate of the at least one processing gas.

[0071] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to the conductive components of the substrate support 11 and / or the conductive components of the nozzle 13. Plasma is thus formed by at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the conductive components of the substrate support 11, a bias potential can be generated on the substrate W, introducing ionic components from the formed plasma into the substrate W.

[0072] In one exemplary embodiment, the radio frequency (RF) power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is configured to couple with a conductive component of the substrate support 11 and / or a conductive component of the nozzle 13 via at least one impedance matching circuit to generate a source RF signal (source RF power) for plasma generation. In one exemplary embodiment, the source RF signal is a continuous wave or pulse wave comprising a high frequency in the range of 13MHz to 150MHz. In one exemplary embodiment, the first RF generation unit 31a may be configured to generate multiple source RF signals with different frequencies. The generated one or more source RF signals are supplied to the conductive components of the substrate support 11 and / or the nozzle 13. The one or more source RF signals may be supplied in the substrate support 11 to the base 113, the suction cup electrode 115, or the bias electrode 116. The second RF generation unit 31b is configured to couple with a conductive component of the substrate support 11 via at least one impedance matching circuit to generate a bias RF signal (bias RF power). In one exemplary embodiment, the bias RF signal has a lower frequency than the source RF signal. In one exemplary embodiment, the bias radio frequency signal is a continuous wave or pulse wave consisting of a high frequency in the range of 400 kHz to 13.56 MHz. In one exemplary embodiment, the second radio frequency generation unit 31b may be configured to generate multiple bias radio frequency signals with different frequencies. One or more bias radio frequency signals generated are supplied to the base 113, chuck electrode 115, or bias electrode 116 of the substrate support unit 11. Furthermore, in various embodiments, at least one of the source radio frequency signal and the bias radio frequency signal may be pulsed.

[0073] Furthermore, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one exemplary embodiment, the first DC generation unit 32a is configured to be connected to a conductive component of the substrate support 11 to generate a first DC signal. The generated first bias DC signal is applied to the conductive component of the substrate support 11. In one exemplary embodiment, the first DC signal may be applied to electrodes 116a and / or 116b included in the base 113, suction cup electrode 115, or bias electrode 116 of the substrate support 11. In one exemplary embodiment, the second DC generation unit 32b is configured to be connected to a conductive component of the nozzle 13 to generate a second DC signal. The generated second DC signal is applied to the conductive component of the nozzle 13. In various embodiments, at least one of the first and second DC signals may be pulsed. Furthermore, the first and second DC generating units 32a and 32b can be provided in addition to the RF power supply 31, or the first DC generating unit 32a can replace the second RF generating unit 31b.

[0074] DC power supply 32 is generated and applied to suction cup electrode 115 (reference). Figure 2 The DC power supply 30 includes electrodes 115a, 115b, and 115c. Electrodes 115b and 115c can form a bipolar electrostatic chuck. Alternatively, electrodes 115a, 115b, and 115c can be integrally formed. The DC power supply 32 can be configured to apply different DC voltages to electrodes 115a, 115b, and 115c, or it can be configured to apply the same DC voltage. In addition to the DC power supply 32, the power supply 30 can also have a power source that generates the voltage applied to the chuck electrodes 115.

[0075] The exhaust system 40 can be connected to a gas outlet 10e, for example, located at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure within the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may also include a turbomolecular pump, a drying pump, or a combination thereof.

[0076] The control unit 50 processes computer-executable instructions that cause the substrate processing apparatus 1 to execute the various processes described herein. The control unit 50 can be configured to control various elements of the substrate processing apparatus 1 in a manner that executes the various processes described herein. In one exemplary embodiment, part or all of the control unit 50 may be provided as part of a configuration of an external device of the substrate processing apparatus 1. The control unit 50 may, for example, include a computer 50a. The computer 50a may, for example, include a processing unit (CPU: Central Processing Unit) 50a1, a storage unit 50a2, and a communication interface 50a3. The processing unit 50a1 can be configured to perform various control actions based on a program stored in the storage unit 50a2. The storage unit 50a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or combinations thereof. The communication interface 50a3 can communicate with other components of the substrate processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0077] In addition to capacitively coupled plasma (CCP), the plasma formed in the plasma processing space can also be inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR), helicon wave plasma (HWP), or surface wave plasma (SWP). Furthermore, various types of plasma generation units, including alternating current (AC) and direct current (DC) plasma generation units, can be used. In one embodiment, the AC signal (AC power) used in the AC plasma generation unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 200 kHz to 150 MHz.

[0078] Figure 3 This is a flowchart illustrating a plasma processing method (hereinafter also referred to as "this processing method") according to an exemplary embodiment. Figure 4This is an example of a timing diagram representing the first, second, and third source radio frequency signals and the bias DC signal in this processing method. Figures 5A to 5C This is a diagram illustrating an example of the electrical pulse P1 contained in the bias signal. Figure 6 This is a diagram illustrating an example of the electrical pulse P2 contained in the second source radio frequency signal. Figure 7 This diagram illustrates an example of the electrical pulse P3 contained in a third-source radio frequency signal. Figures 4 to 7 In the diagram, the horizontal axis represents time. Furthermore, in... Figures 4 to 7 In the diagram, the vertical axis represents the power level of each source RF signal (for example, the effective value of the power of each source RF signal) and / or the voltage, voltage level, or power level of the bias signal.

[0079] exist Figure 4 In this example, the bias DC signal is a bias signal. The "VL" and "VH" of the bias DC signal represent the voltage level of the bias DC signal (as an example, the effective value of the bias DC signal voltage). In... Figure 4 In the example shown, the bias applied to the substrate support 11 by the bias DC signal is larger during the H period than during the L period. Furthermore, as in... Figure 5C As will be described later, the bias signal can be a bias radio frequency signal.

[0080] In addition, Figure 4 In this context, "L1" in the first source radio frequency signal (an example of a "first high-frequency signal") indicates that the power level of the high frequency constituting the first source radio frequency signal is zero or lower than the power level represented by "H1". Furthermore, in... Figure 4 In this context, "L2" for the second source radio frequency signal (an example of a "second high-frequency signal") indicates that the power level of the high frequency constituting the second source radio frequency signal is zero or lower than the power level represented by "H2". "L3" for the third source radio frequency signal (an example of a "third high-frequency signal") indicates that the power level of the high frequency constituting the third source radio frequency signal is zero or lower than the power level represented by "H3".

[0081] like Figure 3As shown, this processing method includes a step of placing a substrate W on a substrate support 11 (ST1), a step of supplying processing gas into a plasma processing chamber 10 (ST2), a step of periodically supplying a first source radio frequency signal (as an example of a first high-frequency signal) to the substrate support 11 (ST3), a step of periodically supplying a second source radio frequency signal (as an example of a second high-frequency signal) to the substrate support 11 (ST4), a step of supplying a third source radio frequency signal (as an example of a third high-frequency signal) to the substrate support 11 (ST5), a step of supplying a bias signal (ST6), a step of determining the end of etching (ST7), and a step of stopping the supply of each signal (the first, second, and third source radio frequency signals and the bias signal) and the processing gas (ST8).

[0082] In process ST1, a substrate W is disposed on the substrate support 11. The substrate W can be, for example, a substrate on which a base film has been deposited on a silicon wafer, an etchable film etched by this process, or a mask film having a predetermined pattern. The etchable film can be, for example, a dielectric film, a semiconductor film, or a metal film.

[0083] In step ST2, a processing gas is supplied to the plasma processing chamber 10. The processing gas is a gas used to etch the film formed on the substrate W. The type of processing gas can be appropriately selected based on the material of the film to be etched, the material of the mask film, the material of the base film, the pattern of the mask film, the etching depth, etc.

[0084] In processes ST3 to ST5, first, second, and third source radio frequency signals are supplied to the substrate support unit 11. The first radio frequency generation unit 31a can either generate each source radio frequency signal as a separate signal and supply it to the substrate support unit 11, or it can supply a signal composed of a composite wave that combines the waveforms of each source radio frequency signal to the substrate support unit 11.

[0085] The first source radio frequency signal, as an example, is a high-frequency continuous wave with a power level of H1. The second source radio frequency signal is as follows... Figure 6 As shown, for example, it is a signal that alternately repeats the L period, which is a low-power period constituting the high frequency of the second source radio frequency signal, and the H period, which is a high-power period. Furthermore, the third source radio frequency signal is as follows... Figure 7 As shown, for example, it is a signal that alternately repeats a period L, which is a low-power period constituting the high frequency of the third source radio frequency signal, and a period H, which is a high-power period. That is, the second source radio frequency signal and the third source radio frequency signal are pulse waves that contain electrical pulses composed of high frequencies during the H period.

[0086] The high frequencies constituting the first, second, and third source radio frequency signals can each have different frequencies. For example, the frequencies of the high frequencies constituting the first, second, and third source radio frequency signals can be in the range of 1 to 200 MHz. Furthermore, the frequencies of each high frequency can be any one of 13.56 MHz, 40.68 MHz, 60 MHz, and 100 MHz. For example, the frequencies of the high frequencies constituting the first, second, and third source radio frequency signals are 40.68 MHz, 60 MHz, and 100 MHz, respectively. The high frequencies constituting the first, second, and third source radio frequency signals can each be an integer multiple of a certain frequency. In this processing method, the second and / or third source radio frequency signals are superimposed relative to the first source radio frequency signal to form a composite wave. In such cases... Figure 4 In the example shown, a composite wave is formed by superimposing two source radio frequency signals (the second and third source radio frequency signals) onto the first source radio frequency signal. The number of radio frequency signals superimposed on the first source radio frequency signal can be one or more, or three or more. Furthermore, the frequency of the source radio frequency signals superimposed on the first source radio frequency signal (e.g., the second and third source radio frequency signals) can be modulated according to the frequency at which the pulse voltage P recurs in the bias DC signal or the frequency of the high frequencies contained in the bias radio frequency signal. For example, the modulation amount of the frequency of the source radio frequency signals superimposed on the first source radio frequency signal (e.g., the second and third source radio frequency signals) can be the frequency at which the pulse voltage P recurs in the bias DC signal or the frequency of the high frequencies contained in the bias radio frequency signal is set to an upper and lower limit range. For example, when the frequency of the second source radio frequency signal is 40.68 MHz and the frequency at which the pulse voltage P recurs in the bias DC signal is 400 kHz, the frequency of the second source radio frequency signal can be modulated within the range of 40.68 MHz ± 400 kHz.

[0087] When the first, second, and / or third source radio frequency signals are supplied to the substrate support 11, plasma is formed by the processing gas supplied to the plasma processing chamber 10. In other embodiments, each source radio frequency signal can be supplied to the upper electrode included in the nozzle 13. Furthermore, this processing method can be performed using a substrate processing apparatus that uses any plasma source, such as inductively coupled plasma or microwave plasma, in addition to the capacitively coupled substrate processing apparatus 1. In this case, the first, second, and / or third source radio frequency signals can be supplied to any electrode or coil included in each substrate processing apparatus.

[0088] In process ST6, a bias signal is applied to the substrate support 11. As an example, if the bias signal is a bias DC signal, such as... Figure 4As shown, the bias DC signal can be a pulse wave that alternately repeats a period H during which the effective value of its voltage is VL and a period L during which the effective value of its voltage is VH, which is higher than VL. For example, the bias DC signal includes an electrical pulse P1 during the H period where the effective value of its voltage is negative. In the bias signal, the electrical pulse P1 appears periodically. The frequency at which the electrical pulse P1 repeats in the bias DC signal can be from 10Hz to 2MHz. Furthermore, this frequency can be from 10Hz to 100kHz. In one example, this frequency is... Figure 4 The reciprocal of PDa during the period. For example... Figure 4 As shown, in a biased DC signal, the electrical pulse P1 can appear periodically with a period of PDa. The electrical pulse P1 is as follows... Figure 5A as well as Figure 5B As shown, it can contain more than one pulse voltage P. Figure 5A This represents an example where the electrical pulse P1 contains two or more pulse voltages P. Furthermore, Figure 5B This represents an example where an electrical pulse P1 contains a pulse voltage P.

[0089] like Figure 5A as well as Figure 5B As shown, for example, the bias DC signal can be a certain voltage V1 (=VH) during L. V1 can be 0V, a positive voltage, or a negative voltage. Furthermore, as an example, such as... Figure 5A As shown, during the H period of the bias DC signal, the electrical pulse P1 of the bias DC signal can be constructed by including periodically repeating pulse voltage P. In the case of... Figure 5A In the example shown, the frequency at which the pulse voltage P recurs in the bias DC signal can be from 50 kHz to 2 MHz. Furthermore, this frequency can be from 100 kHz to 800 kHz. In one example, this frequency is... Figure 5A The reciprocal of the sum of the duration of a pulse voltage P and the duration of its cessation. Furthermore, as... Figure 5B As shown, during the L period of the bias DC signal, the electrical pulse P1 of the bias DC signal can be constituted by a pulse voltage P. In the case of... Figure 5B In the example shown, the frequency at which the pulse voltage P or electrical pulse P1 repeats in the bias DC signal can be from 50 kHz to 2 MHz. Furthermore, this frequency can be from 100 kHz to 800 kHz. In one example, this frequency is... Figure 5B The reciprocal of the sum of periods Ta1 and Ta2. In, for example... Figure 5A as well as Figure 5BIn the example shown, the pulse voltage P includes V2, which is a voltage lower than V1. V2 can be a negative voltage. In addition, the waveform of the one or more pulse voltages P included in the electrical pulse P1 can be a triangular wave, a trapezoidal wave, a pulse, etc., in addition to the rectangular wave shown in FIG5. The voltage can change at a certain period and apply a predetermined bias voltage to the upper electrode or the substrate support portion 11.

[0090] like Figure 5C As shown, the bias signal can also be a bias radio frequency signal. In, for example... Figure 5C In the example shown, the bias radio frequency signal can be a pulse wave containing an electrical pulse P1 during period H. The electrical pulse P1 can be composed of a high-frequency continuous wave. That is, in the example shown... Figure 5C In the example shown, the bias RF signal can be a signal that alternately repeats a high-power period (H period) and a low-power period (L period) constituting the high frequency of the bias RF signal. The power level of the bias RF signal can be zero during the L period. Furthermore, the frequency of the high frequency contained in the electrical pulse P1 can be, for example, 50 kHz to 15 MHz. Alternatively, this frequency can be 200 kHz to 15 MHz. Furthermore, the frequency at which the electrical pulse P1 repeats in the bias RF signal can be 10 Hz to 2 MHz. Alternatively, this frequency can be 10 Hz to 100 kHz.

[0091] Furthermore, processes ST3 through ST6 can start simultaneously or at different times. If processes ST3 through ST6 start at different times, their order can be arbitrary.

[0092] In step ST7, a decision is made as to whether to end the etching process of the film being etched. If the etching process continues, the process returns to step ST3 and continues from step ST3 to step ST7. On the other hand, if the etching process is to be ended, in step ST8, the supply of all signals and processing gas is stopped, and the etching process ends.

[0093] Figure 4 And from Figures 8 to 25 This is an example of a timing diagram of a bias DC signal and the first, second, and third source RF signals, which are examples of bias signals in processes ST3 to ST6. Figure 4 And from Figures 8 to 25 This indicates a portion of the period from process ST3 to process ST6. See below for reference. Figure 4 And from Figures 8 to 25 The relationships between the signals in processes ST3 to ST6 will be explained. Furthermore, in cases such as... Figure 4 And from Figures 8 to 25 In the example shown, the bias radio frequency signal can be supplied to the substrate support 11 instead of the bias DC signal.

[0094] Figure 4 This is a timing diagram illustrating an example of the processing method. In this example, when the first, second, and / or third source radio frequency signals are supplied to the substrate support 11, plasma of the processing gas is generated in the plasma processing chamber 10. On the other hand, the bias DC signal includes a pulse voltage P (refer to...). Figure 5A as well as Figure 5B The H-period and voltage level of the electrical pulse P1 constitute a certain L-period. Then, during the H-period, when the electrical pulse P1 (i.e., pulse voltage P) of the bias DC signal is applied to the substrate support 11, active species present in the plasma generated by the first, second, and / or third source radio frequency signals are introduced into the substrate W disposed on the substrate support 11. As a result, positive ions collide and form an etched film on the substrate W, etching the etched film.

[0095] Specifically, at time t1, the voltage level of the bias DC signal becomes VL. Consequently, an electrical pulse P1 appears in the bias DC signal, and this electrical pulse P1 is applied to the substrate support 11 (hereinafter, the appearance of the electrical pulse P1 in the bias signal will also be referred to as "electrical pulse P1 on"). Then, the electrical pulse P1 is applied to the substrate support 11 between time t1 and time t2 (during period Ta1). When the electrical pulse P1 is applied to the substrate support 11, active species present in the plasma are introduced into the substrate W disposed on the substrate support 11. As a result, positive ions collide with and form an etchable film on the substrate W, etching the etchable film.

[0096] At time t2, when the voltage level of the bias DC signal becomes VH, the electrical pulse P1 in the bias DC signal stops, and the application of electrical pulse P1 to the substrate support 11 ceases (hereinafter, the cessation of electrical pulse P1 in the bias signal will also be referred to as "electrical pulse P1 off"). Then, at time t3, after a period Ta2 from time T2, the period PDa, which is one cycle of the bias DC signal, ends. Furthermore, at time t3, the voltage level of the bias DC signal becomes VL again, and the next cycle of the bias DC signal begins.

[0097] The second source RF signal is phase-synchronized with the bias DC signal, and its power level changes periodically. In such cases... Figure 4 In the example shown, firstly, from time 0 to time t1, the voltage level of the second source radio frequency signal becomes H2. Consequently, an electrical pulse P2 (referencing) containing high frequency appears in the second source radio frequency signal. Figure 6The second source radio frequency signal is supplied to the substrate support section 11 (hereinafter, the appearance of electrical pulse P2 in the second source radio frequency signal will also be referred to as "electrical pulse P2 on"). Then, at time t1, when the electrical pulse P1 of the bias DC signal is turned on, the voltage level of the second source radio frequency signal becomes L2. As a result, the electrical pulse P2 of the second source radio frequency signal stops, and the supply of electrical pulse P2 to the substrate support section 11 stops (hereinafter, the stopping of electrical pulse P2 in the second source radio frequency signal will also be referred to as "electrical pulse P2 off").

[0098] At time t2, after a period Tb1 has elapsed from time t1, when electrical pulse P1 is turned off, electrical pulse P2 of the second source RF signal is turned on. Then, at time t3, after a period Tb2 has elapsed from time t2, PDb, which constitutes one cycle of the second source RF signal, ends. Furthermore, at time t3, electrical pulse P2 of the second source RF signal is turned on again, and the next cycle of the second source RF signal begins.

[0099] The third-source radio frequency signal is phase-synchronized with the bias DC signal, and its power level changes periodically. In such cases... Figure 4 In the example shown, firstly, from time 0 to time t1, the voltage level of the third source radio frequency signal becomes H3. Therefore, an electrical pulse P3 (referencing) consisting of high frequency appears in the third source radio frequency signal. Figure 6 An electrical pulse P3 is supplied to the substrate support section 11 (hereinafter, the appearance of the electrical pulse P3 in the third source RF signal will also be referred to as "electrical pulse P3 on"). Then, at time t1, when the pulse of the bias DC signal is turned on, the voltage level of the third source RF signal becomes L3. As a result, the electrical pulse P3 of the third source RF signal stops, and the supply of electrical pulse P3 to the substrate support section 11 stops (hereinafter, the stopping of electrical pulse P3 in the second source RF signal will also be referred to as "electrical pulse P3 off").

[0100] At time t2, after the period Tc1 has elapsed from time t1, the electrical pulse P1 of the bias voltage is turned off, and the electrical pulse P3 of the third source RF signal is turned on. Then, at time t3, after the period Tc2 has elapsed from time t2, PDc, which is one cycle of the third source RF signal, ends. Furthermore, at time t3, the electrical pulse P3 of the third source RF signal is turned on again, and the next cycle of the third source RF signal begins.

[0101] Thus, in such Figure 4In the example shown, during period Ta1, the high frequency of the first source radio frequency signal and the electrical pulse P1 (i.e., pulse voltage P) are supplied to the substrate support 11. Conversely, during period Ta2 when the electrical pulse P1 of the bias DC signal is off, a composite wave of the high frequencies contained in the first, second, and third source radio frequency signals is supplied to the substrate support 11. Therefore, during period Ta2 when the electrical pulse P1 is not applied to the substrate support 11, the effects of reflections of the first source radio frequency signal on the plasma density can be reduced. Thus, the plasma generation efficiency based on the source radio frequency signal can be improved. Furthermore, during period Ta2 when the electrical pulse P1 is not applied to the substrate support 11, the plasma density can be increased and the electron temperature in the plasma can be reduced. Furthermore, the plasma density and / or the electron temperature in the plasma can be controlled according to the timing of the electrical pulse P1 applied to the substrate support 11.

[0102] Figure 8 This is a timing diagram representing other examples of this processing method. Figure 8 Examples and in Figure 4 The examples described differ in the timing of the on / off of the electrical pulses P2 and P3 of the second and third source radio frequency signals. That is, in Figure 8 In the example, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt earlier than the time t1 when the electrical pulse P1 of the bias DC signal turns on. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are off are only Δt ahead in time compared to the period Ta1 during which the pulse voltage P1 of the bias DC signal turns on. Similarly, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt earlier than the time t2 when the electrical pulse P1 of the bias DC signal turns off. That is, the periods Tb2 and Tc2 during which the electrical pulses P2 and P3 of the second and third source RF signals are on are only Δt ahead in time compared to the period Ta2 during which the electrical pulse P1 of the bias DC signal turns off.

[0103] Thus, as Figure 8 The example shown is at the point where the lengths of periods PDb and PDc are equal to the length of period PDa. Figure 4 The examples are consistent. Furthermore, such as... Figure 8 The example shown has the duty cycles of the second and third source RF signals matching the duty cycle of the bias DC signal. On the other hand, as... Figure 8 The example shown is at points where periods Tb1 and Tb2 and periods Tc1 and Tc2 advance only Δt compared to periods Ta1 and Ta2, respectively. Figure 4 The examples are different.

[0104] Figure 9 This is a timing diagram representing other examples of this processing method. Figure 9Examples and in Figure 4 The examples described differ in the timing of the on / off of the electrical pulses P2 and P3 of the second and third source radio frequency signals. That is, in cases such as Figure 9 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt later than the time t1 when the electrical pulse P1 of the bias DC signal turns on. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are off are only Δt later in time than the period Ta1 during which the electrical pulse P1 of the bias DC signal turns on. Similarly, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt later than the time t2 during which the electrical pulse P1 of the bias DC signal turns off. That is, the periods Tb2 and Tc2 during which the electrical pulses P2 and P3 of the second and third source RF signals are on are only Δt later in time than the period Ta2 during which the electrical pulse P1 of the bias DC signal turns off.

[0105] Thus, as Figure 9 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 4 The examples shown are consistent. Furthermore, as... Figure 9 The example shown is at the points where the duty cycles of the second and third source RF signals are equal to the duty cycle of the bias DC signal, and as shown... Figure 4 The examples shown are consistent. On the other hand, as... Figure 9 The example shown is at points where periods Tb1 and Tb2 and periods Tc1 and Tc2 are only Δt later than periods Ta1 and Ta2, respectively. Figure 4 The examples shown are different.

[0106] Figure 10 This is a timing diagram representing other examples of this processing method. For example... Figure 10 The example shown is similar to that in Figure 4 The examples described differ in the timing of the activation of electrical pulses P2 and P3 of the second and third source radio frequency signals. That is, in the example described... Figure 10 In the example shown, the electrical pulses P2 and P3 of the second and third source radio frequency signals are turned on only Δt earlier than the time t2 when the electrical pulse P1 of the bias DC signal is turned off.

[0107] Thus, as Figure 10 The example shown compares the points where the lengths, start and end times of periods PDb and PDc are equal to those of period PDA. Figure 4 The examples shown are consistent. On the other hand, as... Figure 10 The example shown is at the points where the duty cycles of the second and third source RF signals differ from the duty cycle of the bias DC signal, as shown in the example. Figure 4 The examples shown are different.

[0108] Figure 11 This is a timing diagram representing other examples of this processing method. For example... Figure 11 The example shown is similar to that in Figure 4 The examples described differ in the timing of the shutdown of electrical pulses P2 and P3 of the second and third source RF signals. That is, in the example described... Figure 11 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt later than the time t1 when the electrical pulse P1 of the bias DC signal turns on. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn on at the time t2 when the electrical pulse P1 of the bias DC signal turns off.

[0109] Thus, as Figure 11 The example shown is related to the timing of the activation of electrical pulses P2 and P3 of the second and third source RF signals, as follows: Figure 4 The examples shown are consistent. Furthermore, as... Figure 11 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 4 The examples shown are consistent. On the other hand, as... Figure 11 The example shown compares the timings at points where the time series starting in period Tb1 and period Tc1 are only Δt later than the time series starting in period Ta1. Figure 4 The examples shown are different. Furthermore, as... Figure 11 The example shown is at the point where the timing of the end of period Tb2 and period Tc2 is only Δt later than the timing of the end of period Ta2, and is similar to... Figure 4 The examples shown are different. Furthermore, as... Figure 11 The example shown is at the points where the duty cycles of the second and third source RF signals differ from the duty cycle of the bias DC signal, as shown in the example. Figure 4 The examples shown are different.

[0110] Figure 12 This is a timing diagram representing other examples of this processing method. For example... Figure 12 The example shown is similar to that in Figure 4 The examples described differ in the timing of the shutdown of electrical pulses P2 and P3 of the second and third source RF signals. That is, in the example described... Figure 12In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt earlier than the time t1 when the electrical pulse P1 of the bias DC signal turns on. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn on at the time t2 when the electrical pulse P1 of the bias DC signal turns off. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are off begin only Δt earlier than the period Ta1 during which the bias DC signal is on, and end simultaneously with Ta1. Moreover, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt earlier than the time t3 when the electrical pulse P1 of the bias DC signal turns on.

[0111] Thus, as Figure 12 The example shown is related to the timing of the activation of electrical pulses P2 and P3 of the second and third source radio frequency signals as follows: Figure 4 The examples shown are consistent. Furthermore, as... Figure 12 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 4 The examples shown are consistent. On the other hand, as... Figure 12 The example shown has points where the timing of periods Tb1 and Tc1 begins Δt earlier than that of period Ta1 only in time. Figure 4 The examples shown are different. Furthermore, as... Figure 12 The example shown is at the point where the time series ending during period Tb2 and period Tc2 ends only Δt earlier than the time series ending during period Ta2, as shown in the example. Figure 4 The examples shown are different. Furthermore, as... Figure 12 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 4 The examples shown are different.

[0112] Figure 13 This is a timing diagram representing other examples of this processing method. For example... Figure 13 The example shown is similar to that in Figure 4 The examples described differ in the timing of the activation of electrical pulses P2 and P3 of the second and third source radio frequency signals. That is, in the example described... Figure 13 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt later than the time T2 when the electrical pulse P1 of the bias DC signal turns off. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are off begin simultaneously with the period Ta1, and end only Δt later than the period Ta1 during which the electrical pulse P1 of the bias DC signal turns on. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn off at the time t3 when the electrical pulse P1 of the bias DC signal turns on.

[0113] Thus, as Figure 13 The example shown is related to the timing of the shutdown of electrical pulses P2 and P3 of the second and third source RF signals as follows: Figure 4 The examples shown are consistent. Furthermore, as... Figure 13 The example shown is at the point where the lengths and start and end times of periods PDb and PDc are equal to those of period PDA, as shown in the example. Figure 4 The examples shown are consistent. On the other hand, as... Figure 13 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 4 The examples shown are different.

[0114] Figure 14 This is a timing diagram representing other examples of this processing method. For example... Figure 14 The example shown is similar to that in Figure 4 The examples described differ in the timing of the on and off of the electrical pulses P2 and P3 of the second and third source radio frequency signals. That is, in the example described... Figure 14 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt later than the time t1 when the electrical pulse P1 of the bias DC signal turns on, and turn on only Δt earlier than the time t2 when the electrical pulse P1 of the bias DC signal turns off. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are off begin only Δt later than the period Ta1, and end only Δt earlier. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt later than the time t3 when the electrical pulse P1 of the bias DC signal turns on.

[0115] Thus, as Figure 14 The example shown illustrates points where the lengths of periods PDb and PDc are equal to those of period PDa. Figure 4 The examples shown are consistent. On the other hand, as... Figure 14 The example shown is at the point where the timing of the electrical pulses P2 and P3 of the second and third source radio frequency signals turns on and off is different, as shown in the example. Figure 4 The examples shown are different. Furthermore, as... Figure 14 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 4 The examples shown are different.

[0116] Figure 15 This is a timing diagram representing other examples of this processing method. For example... Figure 15 The example shown is similar to that in Figure 4 The examples described differ in the timing of the on and off of the electrical pulses P2 and P3 of the second and third source radio frequency signals. That is, in the example described... Figure 15 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt earlier than the time t1 when the bias DC signal electrical pulse P1 turns on, and turn on only Δt later than the time t2 when the bias DC signal electrical pulse P1 turns off. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are off begin only Δt earlier than the period Ta1, and end only Δt later. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt earlier than the time t3 when the bias DC signal electrical pulse P1 turns on.

[0117] Thus, as Figure 15 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 4 The examples shown are consistent. On the other hand, as... Figure 15 The example shown differs from the example shown at the points where the electrical pulses P2 and P3 of the second and third source RF signals are turned on and off, respectively. Figure 4 The examples shown are different. Furthermore, as... Figure 15 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 4 The examples shown are different.

[0118] From Figures 8 to 15 In the example shown, besides based on such Figure 4 Beyond the effects shown in the example, the timing of the opening and closing of the electrical pulses P2 and P3 of the second and third source radio frequency signals can be controlled based on the timing of the opening and closing of the bias DC signal electrical pulse P1. That is, the timing of the closing or shutting down of the electrical pulses P2 and P3 of the second and third source radio frequency signals can be appropriately controlled according to the timing of the reflection of the first source radio frequency signal and the opening or closing of the bias DC signal electrical pulse P1, which affect the plasma density. Therefore, the plasma generation efficiency based on the source radio frequency signals can be improved. Consequently, plasma density and / or electron temperature can be controlled.

[0119] Figure 16 This is a timing diagram representing other examples of this processing method. For example... Figure 16 The example shown is similar to that in Figure 4 In the example described, the phases of the second and third source radio frequency signals are out of phase. That is, in the example described... Figure 16 In the example shown, when the bias DC signal pulse P1 is turned on or off, the second and third source RF signal pulses P2 and P3 are also turned on or off.

[0120] At time t1, the bias DC signal pulse P1 is turned on, and the second and third source RF signal pulses P2 and P3 are also turned on. Then, at time t2, after a period Ta1 (Tb1, Tc1) from time t1, when the bias DC signal pulse P1 is turned off, the second and third source RF signal pulses P2 and P3 are turned off. Then, at time t3, after a period Ta2 (Tb2, Tc2) from time t2, the period PDa (PDb, PDc), which is one cycle of the bias DC signal and the second and third source RF signals, ends. Furthermore, at time t3, the next cycle of the bias DC signal and the second and third source RF signals begins.

[0121] Thus, in such Figure 16 In the example shown, during the period Ta1 when the bias DC signal electrical pulse P1 is turned on, the electrical pulse P1 is supplied to the substrate support 11, and a composite wave of the first, second, and / or third source radio frequency signals is supplied. That is, during the period Ta1 when the bias DC signal electrical pulse P1 is turned on, i.e., the timing when active species in the plasma are introduced into the substrate W through the electrical pulse P1, the second and third source radio frequency signals are supplied to the substrate support 11 by superimposing the first source radio frequency signal. As a result, the plasma density can be increased during the timing when active species in the plasma are introduced into the substrate W. In addition, the electron temperature in the plasma can be increased. Furthermore, in the case of... Figure 16 In the example shown, a composite wave of the first, second, and / or third source radio frequency signals is supplied when the bias DC signal pulse P1 is turned on. Here, the first, second, and / or third source radio frequency signals can each have different frequencies. That is, when the bias DC signal pulse P1 is turned on, source radio frequency signals containing multiple frequencies can be supplied to the substrate support 11. Therefore, when the bias DC signal pulse P1 is turned on, reflection of the composite wave of the source radio frequency signals can be suppressed. Thus, plasma formation becomes easier. Furthermore, in the case of… Figure 16 In the example shown, even if the impedance of the synthesized wave relative to the first, second, and third source RF signals changes, impedance integration can be achieved through any one of the first, second, and third source RF signals. Therefore, when, for example, the electrical pulse P1 of the bias DC signal is turned on, if the impedance relative to the synthesized wave changes, even if the amount of reflection of the synthesized wave changes, the change can be suppressed.

[0122] In addition, in such Figure 16 (as well as Figures 17 to 24In the example shown, during a portion of the period when the bias DC signal pulse P1 is off (i.e., period Ta2), the power levels of the first, second, and third source RF signals can simultaneously be L1, L2, and L3, respectively. In this case, the power levels L1, L2, and L3 can all be zero. Furthermore, during a portion of the period when the bias DC signal pulse P1 is off (i.e., period Ta2), a composite wave with an out-of-phase phase to the first source RF signal can also be generated from the second and / or third source RF signals and superimposed on the first source RF signal. That is, a composite wave with a power level of zero can also be generated from the second and third source RF signals.

[0123] Figure 17 This is a timing diagram representing other examples of this processing method. For example... Figure 17 The example shown is similar to that in Figure 8 In comparison to the example described, the phases of the second and third source radio frequency signals are out of phase.

[0124] In such Figure 17 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt earlier than the time t1 when the electrical pulse P1 of the bias DC signal turns on. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are on advance by only Δt in time compared to the period Ta1 during which the electrical pulse P1 of the bias DC signal is on. Similarly, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt earlier than the time t2 when the electrical pulse P1 of the bias DC signal turns off. That is, the periods Tb2 and Tc2 during which the electrical pulses P2 and P3 of the second and third source RF signals are on advance by only Δt in time compared to the period Ta2 during which the electrical pulse P1 of the bias DC signal is off.

[0125] Thus, as Figure 17 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 16 The examples shown are consistent. Furthermore, as... Figure 17 The example shown illustrates that the duty cycles of the second and third source RF signals are consistent with the duty cycle of the bias DC signal. On the other hand, as... Figure 8 The example shown is at points where periods Tb1 and Tb2 and periods Tc1 and Tc2 advance by only Δt compared to periods Ta1 and Ta2, respectively, and as shown in the example. Figure 16 The examples shown are different.

[0126] Figure 18 This is a timing diagram representing other examples of this processing method. For example... Figure 18 The example shown is similar to that in Figure 9In comparison to the example described, the phases of the second and third source radio frequency signals are out of phase.

[0127] In such Figure 18 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt later than the time t1 when the electrical pulse P1 of the bias DC signal turns on. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are on are only Δt later than the period Ta1 during which the electrical pulse P1 of the bias DC signal turns on. Similarly, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt later than the time t2 when the electrical pulse P1 of the bias DC signal turns off. That is, the periods Tb2 and Tc2 during which the electrical pulses P2 and P3 of the second and third source RF signals are on are only Δt later than the period Ta2 during which the electrical pulse P1 of the bias DC signal turns on.

[0128] Thus, as Figure 18 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 16 The examples shown are consistent. Furthermore, as... Figure 18 The example shown is at the points where the duty cycles of the second and third source RF signals are equal to the duty cycle of the bias DC signal, and as shown... Figure 16 The examples shown are consistent. On the other hand, as... Figure 18 The example shown is at points where periods Tb1 and Tb2 and periods Tc1 and Tc2 are only Δt later than periods Ta1 and Ta2, respectively. Figure 16 The examples shown are different.

[0129] Figure 19 This is a timing diagram representing other examples of this processing method. For example... Figure 19 The example shown is similar to that in Figure 10 In comparison to the example described, the phases of the second and third source radio frequency signals are out of phase.

[0130] In such Figure 19 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals are turned on at the moment t1 when the electrical pulse P1 of the bias DC signal is turned on. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals are turned off only Δt earlier than the moment t2 when the electrical pulse P1 of the bias DC signal is turned off.

[0131] Thus, as Figure 19 The example shown is at the point where the lengths and start and end times of periods PDb and PDc are equal to those of period PDA, as shown in the example. Figure 16 The examples shown are consistent. On the other hand, as... Figure 19The example shown is at the points where the duty cycles of the second and third source RF signals differ from the duty cycle of the bias DC signal, as shown in the example. Figure 16 The examples shown are different.

[0132] Figure 20 This is a timing diagram representing other examples of this processing method. For example... Figure 20 The example shown is similar to that in Figure 11 In comparison to the example described, the phases of the second and third source radio frequency signals are out of phase.

[0133] In such Figure 20 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt later than the time t1 when the electrical pulse P1 of the bias DC signal turns on. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn off at the time t2 when the electrical pulse P1 of the bias DC signal turns off. Additionally, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt later than the time t3 when the electrical pulse P1 of the bias DC signal turns on.

[0134] Thus, as Figure 20 The example shown is similar to the timing of the pulse shutdown of the second and third source RF signals as follows. Figure 16 The examples shown are consistent. Furthermore, as... Figure 20 The example shown illustrates points where the lengths of periods PDb and PDc are equal to those of period PDa. Figure 16 The examples shown are consistent. On the other hand, as... Figure 20 The example shown compares the timings at points where the time series starting in period Tb1 and period Tc1 are only Δt later than the time series starting in period Ta1. Figure 16 The examples shown are different. Furthermore, as... Figure 20 The example shown is at the point where the timing of the end of period Tb2 and period Tc2 is only Δt later than the timing of the end of period Ta2, and is similar to... Figure 16 The examples shown are different. Furthermore, as... Figure 20 The example shown is at the points where the duty cycles of the second and third source RF signals differ from the duty cycle of the bias DC signal, as shown in the example. Figure 16 The examples shown are different.

[0135] Figure 21 This is a timing diagram representing other examples of this processing method. For example... Figure 21 The example shown is similar to that in Figure 12 In comparison to the example described, the phases of the second and third source radio frequency signals are out of phase.

[0136] In such Figure 21In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt earlier than the time t1 when the electrical pulse P1 of the bias DC signal turns on. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn off at the time t2 when the electrical pulse P1 of the bias DC signal turns off. Additionally, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt earlier than the time t3 when the electrical pulse P1 of the bias DC signal turns on.

[0137] Thus, as Figure 21 The example shown is related to the timing of the shutdown of electrical pulses P2 and P3 of the second and third source RF signals as follows: Figure 16 The examples shown are consistent. Furthermore, as... Figure 21 The example shown illustrates points where the lengths of periods PDb and PDc are equal to those of period PDa. Figure 16 The examples shown are consistent. On the other hand, as... Figure 21 The example shown has timing sequences starting at periods Tb1 and Tc1 that are only Δt earlier than period Ta1, similar to... Figure 16 The examples shown are different. Furthermore, as... Figure 21 The example shown is at the point where the time series ending during period Tb2 and period Tc2 ends only Δt earlier than the time series ending during period Ta2, as shown in the example. Figure 16 The examples shown are different. Furthermore, as... Figure 21 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 16 The examples shown are different.

[0138] Figure 22 This is a timing diagram representing other examples of this processing method. For example... Figure 22 The example shown is similar to that in Figure 13 In comparison to the example described, the phases of the second and third source radio frequency signals are out of phase.

[0139] In such Figure 22 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals are turned off only Δt later than the time t2 when the electrical pulse P1 of the bias DC signal is turned off. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals are turned on at the time t3 when the electrical pulse P1 of the bias DC signal is turned on.

[0140] Thus, as Figure 22 The example shown is related to the timing of the shutdown of electrical pulses P2 and P3 of the second and third source RF signals as follows: Figure 16 The examples shown are consistent. Furthermore, as... Figure 22 The example shown compares the points where the lengths, start and end times of periods PDb and PDc are equal to those of period PDA. Figure 16 The examples shown are consistent. On the other hand, as... Figure 22 The example shown compares the timings at the points where the time series ends during period Tb1 and period Tc1 are only Δt later than the time series ending during period Ta1. Figure 16 The examples shown are different. Furthermore, as... Figure 21 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 16 The examples shown are different.

[0141] Figure 23 This is a timing diagram representing other examples of this processing method. For example... Figure 23 The example shown is similar to that in Figure 16 In comparison to the example described, the phases of the second and third source radio frequency signals are out of phase.

[0142] In such Figure 23 In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt later than the turn-on time t1 of the bias DC signal pulse, and turn on only Δt earlier than the turn-off time t2 of the bias DC signal pulse P1. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are on begin only Δt later than the period Ta1, and end only Δt earlier. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn off only Δt later than the turn-on time t3 of the bias DC signal pulse P1.

[0143] Thus, as Figure 23 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 16 The examples shown are consistent. On the other hand, as... Figure 23 The example shown differs from the example shown at the points where the electrical pulses P2 and P3 of the second and third source RF signals are turned on and off, respectively. Figure 16 The examples shown are different. Furthermore, as... Figure 23 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 16 The examples shown are different.

[0144] Figure 24 This is a timing diagram representing other examples of this processing method. For example... Figure 24 The example shown is similar to that in Figure 15 In the example described, the phases of the second and third source radio frequency signals become out of phase. That is, in the case of... Figure 24In the example shown, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt earlier than the time t1 when the bias DC signal electrical pulse P1 turns on, and turn off only Δt later than the time t2 when the bias DC signal electrical pulse P1 turns off. That is, the periods Tb1 and Tc1 during which the electrical pulses P2 and P3 of the second and third source RF signals are on begin only Δt earlier than the period Ta1, and end only Δt later. Furthermore, the electrical pulses P2 and P3 of the second and third source RF signals turn on only Δt earlier than the time t3 when the bias DC signal electrical pulse P1 turns on.

[0145] Thus, as Figure 24 The example shown is at points where the lengths of periods PDb and PDc are equal to those of period PDa, as in... Figure 16 The examples shown are consistent. On the other hand, as... Figure 24 The example shown differs from the example shown at the points where the electrical pulses P2 and P3 of the second and third source RF signals are turned on and off, respectively. Figure 16 The examples shown are different. Furthermore, as... Figure 24 The example shown differs from the example shown at points where the duty cycles of the second and third source RF signals and the bias DC signal are different. Figure 16 The examples shown are different.

[0146] From Figures 17 to 24 In the example shown, besides based on such Figure 16 Beyond the effects shown in the example, the timing of the opening and closing of the electrical pulses P2 and P3 of the second and third source radio frequency signals can be controlled based on the timing of the opening and closing of the bias DC signal electrical pulse P1. Therefore, the plasma density can be increased in a suitable timing manner according to the timing of ion introduction into the substrate W in the plasma. Furthermore, the electron temperature in the plasma can be increased. Additionally, as in... Figures 17 to 24 In the example shown, the synthesized wave of the source radio frequency signal can be supplied to the substrate support 11 at an appropriate timing when the bias DC signal electrical pulse P1 is turned on. Therefore, the reflection of the synthesized wave of the source radio frequency signal can be suppressed when the bias DC signal electrical pulse P1 is turned on. Furthermore, as from... Figures 17 to 24 In the example shown, even if the impedance changes relative to the composite waveform of the first, second, and third source RF signals, impedance integration can be achieved through any one of the first, second, and third source RF signals. Therefore, even when the electrical pulse P1 of the bias DC signal is turned on, the change in the amount of reflection of the composite waveform relative to the impedance change of the composite waveform can be suppressed at an appropriate timing.

[0147] Figure 25 This is a timing diagram representing other examples of this processing method. In, for example... Figure 25In the example shown, the electrical pulse P2 of the second source RF signal is superimposed on the first source RF signal and supplied to the substrate support 11 during the period Tb2 corresponding to the period Ta2 during which the electrical pulse P1 of the bias DC signal is turned off. Furthermore, the electrical pulse P3 of the third source RF signal is superimposed on the first source RF signal and supplied to the substrate support 11 during the period Tc1 corresponding to the period Ta1 during which the electrical pulse P1 of the bias DC signal is turned off.

[0148] In such Figure 25 In the example shown, the electrical pulse P2 of the second source radio frequency signal can be generated as follows: Figures 4 to 15 The example shown illustrates various timing sequences superimposed on the first source RF signal. Furthermore, during the period Tb1 when the electrical pulse P2 of the second source RF signal is activated, electrical pulses of other RF signals can be further superimposed on the first source RF signal. The frequency or power of each RF signal including the second source RF signal can be arbitrarily set or adjusted according to its purpose.

[0149] In such Figure 25 In the example shown, the electrical pulse P3 of the third source radio frequency signal can be generated from... Figures 16 to 24 The example shown illustrates various timing sequences superimposed on the first source RF signal. Furthermore, during the period Tc1 when the electrical pulse P3 of the third source RF signal is activated, electrical pulses of other RF signals can be further superimposed on the first source RF signal. The frequency or power of each RF signal, including the third source RF signal, can be arbitrarily set or adjusted according to its purpose.

[0150] Furthermore, the examples illustrated in the above figures can be appropriately combined and implemented. Additionally, in the examples illustrated in the figures, the number or frequency of each radio frequency signal superimposed on the first source radio frequency signal can be changed based on the plasma processing of this method. That is, the synthesized wave supplied to the substrate support 11 can also be changed according to the plasma processing process based on this method.

[0151] For example, when the etched film etched by this processing method is a multilayer film, the synthetic wave used in etching a specific film within the multilayer film may differ from the synthetic wave used in etching other films within the multilayer film. For instance, if the substrate processing apparatus 1 has a configuration for identifying the type of film to be etched, the synthetic wave used in the etching process can be changed midway through the etching process based on this identification. Therefore, etching conditions can be controlled according to the type of etched film, improving the etch shape, etc. As an example, the configuration for identifying the type of etched film can be an optical emission spectrometer. Furthermore, as an example, the multilayer film can be a laminated film of silicon oxide and silicon nitride.

[0152] Furthermore, for example, when etching holes with high aspect ratios in an etch film using this processing method, the synthetic wave used in this processing method can be appropriately changed according to the progress of the etching (depth or time, etc.). This allows for control of etching conditions based on the etching progress, improving the etch shape, etc. Additionally, for example, the amount of byproducts such as polymers generated by the etching can be controlled by changing the synthetic wave used in this processing method, depending on the progress of the etching based on this processing method.

[0153] Furthermore, in the examples illustrated in the figures, the bias signal is not limited to a rectangular wave. The bias signal can be, for example, a trapezoidal wave, a triangular wave, a sawtooth wave, a sine wave, etc., with a voltage that changes periodically, and can apply a predetermined bias voltage relative to the upper electrode or the substrate support 11. Additionally, the bias DC signal can also be a pulsed radio frequency signal.

[0154] The above embodiments have been described for illustrative purposes and various modifications can be made without departing from the scope and spirit of this disclosure. For example, in addition to the capacitively coupled substrate processing apparatus 1, this processing method can be performed using a substrate processing apparatus that uses any plasma source such as inductively coupled plasma or microwave plasma. Furthermore, this disclosure may include, for example, the following configuration.

[0155] (Postscript 1)

[0156] A plasma processing method involves performing plasma processing on a substrate in a plasma processing apparatus.

[0157] The plasma processing device includes:

[0158] Chambers; and

[0159] A substrate support portion is disposed within the cavity and configured to support the substrate.

[0160] The plasma processing method includes:

[0161] The process of arranging a substrate on the substrate support portion;

[0162] A process of supplying processing gas for processing the substrate into the chamber;

[0163] The process of generating plasma of the processed gas in the chamber using a first high-frequency signal and a second high-frequency signal; and

[0164] The process of supplying a bias signal to the substrate support portion.

[0165] The process of generating the plasma includes a process of superimposing the second high-frequency signal with the first high-frequency signal based on the timing of the bias signal supplied to the substrate support.

[0166] (Postscript 2)

[0167] The plasma treatment method described in Appendix 1, wherein,

[0168] The bias signal is a pulse wave that periodically includes a first electrical pulse.

[0169] The first high-frequency signal is a high-frequency continuous wave with a first frequency.

[0170] The second high-frequency signal is a pulse wave that periodically contains a second electrical pulse.

[0171] The second electrical pulse is composed of a high-frequency continuous wave having a second frequency that is different from the first frequency.

[0172] (Note 3)

[0173] The plasma treatment method described in Appendix 2, among which,

[0174] The first electrical pulse is composed of one or more pulse voltages.

[0175] (Postscript 4)

[0176] The plasma treatment method described in Appendix 2, among which,

[0177] The first electrical pulse is composed of a high-frequency continuous wave.

[0178] (Note 5)

[0179] The plasma treatment method described in Appendix 2, among which,

[0180] The first period, which is the period during which the first electrical pulse repeats in the bias signal, is equal to the second period, which is the period during which the second electrical pulse repeats in the second high-frequency signal.

[0181] (Note 6)

[0182] The plasma treatment method described in any of the appendices 1 to 5, wherein,

[0183] In the process of generating the plasma, the first high-frequency signal and the second high-frequency signal are supplied to the substrate support.

[0184] (Note 7)

[0185] The plasma treatment method described in Appendix 2, among which,

[0186] The timing of the second electrical pulse is equal to the timing of the first electrical pulse stopping.

[0187] (Note 8)

[0188] The plasma treatment method described in Appendix 2, among which,

[0189] The second electrical pulse occurs earlier than the first electrical pulse stops.

[0190] (Note 9)

[0191] The plasma treatment method described in Appendix 2, among which,

[0192] The timing of the second electrical pulse is later than the timing of the first electrical pulse stopping.

[0193] (Postscript 10)

[0194] The plasma processing method described in any of the appendices 7 to 9, wherein,

[0195] The period during which the second electrical pulse stops in the second cycle is equal to the period during which the first electrical pulse occurs in the first cycle.

[0196] (Postscript 11)

[0197] The plasma treatment method described in any of the appendices 5 to 7, wherein,

[0198] In the second cycle, the period during which the second electrical pulse stops is longer than the period during which the first electrical pulse occurs in the first cycle.

[0199] (Postscript 12)

[0200] The plasma processing method described in any of the appendices 7 to 9, wherein,

[0201] The period during which the second electrical pulse stops in the second cycle is shorter than the period during which the first electrical pulse occurs in the first cycle.

[0202] (Postscript 13)

[0203] The plasma treatment method described in Appendix 6, among which,

[0204] The timing of the second electrical pulse is the same as that of the first electrical pulse.

[0205] (Postscript 14)

[0206] The plasma treatment method described in Appendix 6, among which,

[0207] The second electrical pulse occurs earlier than the first electrical pulse.

[0208] (Postscript 15)

[0209] The plasma treatment method described in Appendix 6, among which,

[0210] The timing of the second electrical pulse is later than that of the first electrical pulse.

[0211] (Postscript 16)

[0212] The plasma treatment method described in any of the appendices 13 to 15, wherein,

[0213] The duration of the second electrical pulse in the second cycle is equal to the duration of the first electrical pulse in the first cycle.

[0214] (Postscript 17)

[0215] The plasma treatment method described in any of the appendices 13 to 15, wherein,

[0216] The duration of the second electrical pulse in the second cycle is longer than the duration of the first electrical pulse in the first cycle.

[0217] (Postscript 18)

[0218] The plasma treatment method described in any of the appendices 13 to 15, wherein,

[0219] The duration of the second electrical pulse in the second cycle is shorter than the duration of the first electrical pulse in the first cycle.

[0220] (Postscript 19)

[0221] The plasma treatment method described in any of the appendices 1 to 6, wherein,

[0222] The process of generating the plasma includes a process of further superimposing a third high-frequency signal with the first high-frequency signal based on the timing of the bias signal supplied to the substrate support.

[0223] (Postscript 20)

[0224] The plasma processing method described in Appendix 19, among which,

[0225] The third high-frequency signal is a pulse wave that periodically contains a third electrical pulse.

[0226] The third electrical pulse is composed of a high frequency having a third frequency different from the first frequency and the second frequency.

[0227] At least a portion of the third electrical pulse is superimposed in time with the second electrical pulse and superimposed with the first high-frequency signal.

[0228] (Postscript 21)

[0229] The plasma processing method described in Appendix 19, among which,

[0230] The third high-frequency signal is a pulse wave that periodically contains a third electrical pulse.

[0231] The third electrical pulse is composed of a high frequency having a third frequency different from the first frequency and the second frequency.

[0232] The third electrical pulse does not overlap with the second electrical pulse in time, but overlaps with the first high-frequency signal.

[0233] (Postscript 22)

[0234] The plasma treatment method described in any of the appendices 2 to 22, wherein,

[0235] The second frequency is an integer multiple of the first frequency.

[0236] (Postscript 23)

[0237] The plasma treatment method described in any of the appendices 2 to 22, wherein,

[0238] The pulse voltage includes a negative voltage.

[0239] (Postscript 24)

[0240] A plasma processing device comprising:

[0241] Chamber;

[0242] A substrate support portion is disposed within the cavity and configured to support the substrate; and

[0243] Control Department

[0244] The control unit performs the following controls:

[0245] A substrate is disposed on the substrate support portion;

[0246] Processing gas for processing the substrate is supplied into the chamber;

[0247] Plasma of the processed gas is generated in the chamber by a first high-frequency signal and a second high-frequency signal;

[0248] Apply a bias signal to the substrate support portion; and

[0249] Based on the timing of applying the bias signal to the substrate support portion, the second high-frequency signal is superimposed on the first high-frequency signal.

[0250] Explanation of reference numerals in the attached figures

[0251] 1…substrate processing apparatus, 10…plasma processing chamber, 11…substrate support, 13…nozzle, 20…gas supply unit, 21…gas source, 22…flow controller, 30…power supply, 31…RF power supply, 32…DC power supply, 40…exhaust system, 50…control unit, 111…main body, 112…ring assembly, W…substrate.

Claims

1. A plasma treatment method, comprising performing plasma treatment on a substrate in a plasma treatment apparatus. The plasma processing device includes: Chambers; and A substrate support portion is disposed within the cavity and configured to support the substrate. The plasma processing method includes: The process of arranging a substrate on the substrate support portion; A process of supplying processing gas for processing the substrate into the chamber; The process of generating plasma of the processed gas in the chamber using a first high-frequency signal and a second high-frequency signal; and The process of supplying a bias signal to the substrate support portion. The process of generating the plasma includes a step of superimposing the second high-frequency signal with the first high-frequency signal based on the timing of the bias signal supplied to the substrate support. wherein, The bias signal is a pulse wave that periodically includes a first electrical pulse. The first high-frequency signal is a high-frequency continuous wave with a first frequency. The second high-frequency signal is a pulse wave that periodically contains a second electrical pulse. The second electrical pulse is composed of a high-frequency continuous wave having a second frequency that is different from the first frequency.

2. The plasma treatment method according to claim 1, wherein, The first electrical pulse is composed of one or more pulse voltages.

3. The plasma treatment method according to claim 1, wherein, The first electrical pulse is composed of a high-frequency continuous wave.

4. The plasma treatment method according to claim 1, wherein, The first period, which is the period during which the first electrical pulse repeats in the bias signal, is equal to the second period, which is the period during which the second electrical pulse repeats in the second high-frequency signal.

5. The plasma treatment method according to claim 1, wherein, In the process of generating the plasma, the first high-frequency signal and the second high-frequency signal are supplied to the substrate support.

6. The plasma treatment method according to claim 4, wherein, The timing of the second electrical pulse is equal to the timing of the first electrical pulse stopping.

7. The plasma treatment method according to claim 4, wherein, The second electrical pulse occurs earlier than the first electrical pulse stops.

8. The plasma treatment method according to claim 4, wherein, The timing of the second electrical pulse is later than the timing of the first electrical pulse stopping.

9. The plasma treatment method according to any one of claims 6 to 8, wherein, The period during which the second electrical pulse stops in the second cycle is equal to the period during which the first electrical pulse occurs in the first cycle.

10. The plasma processing method according to any one of claims 6 to 8, wherein, In the second cycle, the period during which the second electrical pulse stops is longer than the period during which the first electrical pulse occurs in the first cycle.

11. The plasma processing method according to any one of claims 6 to 8, wherein, The period during which the second electrical pulse stops in the second cycle is shorter than the period during which the first electrical pulse occurs in the first cycle.

12. The plasma treatment method according to claim 4, wherein, The timing of the second electrical pulse is the same as that of the first electrical pulse.

13. The plasma treatment method according to claim 4, wherein, The second electrical pulse occurs earlier than the first electrical pulse.

14. The plasma treatment method according to claim 4, wherein, The timing of the second electrical pulse is later than that of the first electrical pulse.

15. The plasma treatment method according to any one of claims 12 to 14, wherein, The duration of the second electrical pulse in the second cycle is equal to the duration of the first electrical pulse in the first cycle.

16. The plasma processing method according to any one of claims 12 to 14, wherein, The duration of the second electrical pulse in the second cycle is longer than the duration of the first electrical pulse in the first cycle.

17. The plasma processing method according to any one of claims 12 to 14, wherein, The duration of the second electrical pulse in the second cycle is shorter than the duration of the first electrical pulse in the first cycle.

18. The plasma processing method according to claim 1, wherein, The process of generating the plasma includes a process of further superimposing a third high-frequency signal with the first high-frequency signal based on the timing of the bias signal supplied to the substrate support.

19. The plasma processing method according to claim 18, wherein, The third high-frequency signal is a pulse wave that periodically contains a third electrical pulse. The third electrical pulse is composed of a high frequency having a third frequency different from the first frequency and the second frequency. At least a portion of the third electrical pulse is superimposed on the second electrical pulse in time, and is also superimposed on the first high-frequency signal.

20. The plasma processing method according to claim 18, wherein, The third high-frequency signal is a pulse wave that periodically contains a third electrical pulse. The third electrical pulse is composed of a high frequency having a third frequency different from the first frequency and the second frequency. The third electrical pulse does not overlap with the second electrical pulse in time, but overlaps with the first high-frequency signal.

21. The plasma processing method according to claim 1, wherein, The second frequency is an integer multiple of the first frequency.

22. The plasma treatment method according to claim 2, wherein, The pulse voltage includes a negative voltage.

23. A plasma processing apparatus, comprising: Chamber; A substrate support portion is disposed within the cavity and configured to support the substrate; and Control Department The control unit performs the following controls: A substrate is disposed on the substrate support portion; Processing gas for processing the substrate is supplied into the chamber; Plasma of the processed gas is generated in the chamber by a first high-frequency signal and a second high-frequency signal; A bias signal is applied to the substrate support portion; and The second high-frequency signal is superimposed on the first high-frequency signal based on a timing of applying the bias signal to the substrate support portion, wherein the bias signal is a pulse wave periodically including a first electric pulse, the first high-frequency signal is a continuous wave of high frequency having a first frequency, the second high-frequency signal is a pulse wave periodically including a second electric pulse, the second electric pulse includes a continuous wave of high frequency having a second frequency different from the first frequency.

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