Plasma processing apparatus and plasma processing method

Abstract

To measure an in-surface interior division of a self bias voltage of a substrate support part.SOLUTION: A plasma processing apparatus comprises: a plasma processing chamber; a base; an electrostatic chuck; a plurality of electrode layers arranged in the same in-surface in the electrostatic chuck; a switch group constructed by a plurality of switches electrically connected to each of the plurality of electrode layers; a power supply part and a measurement part that are electrically connected to the switch group; the other switch that selects a connection destination of the switch group from any one of the power supply part and the measurement part; and a control part. The power supply part comprises a power supply that supplies a power to the plurality of electrode layers. The measurement part comprises a voltmeter that measures a resistance and a voltage applied to the resistance. The control part is constructed so as to execute a control of switching the connection destination of the switch group to the measurement part, and after that, switching the plurality of switches constructing the switch group to an on state one by one.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a plasma processing apparatus and a plasma processing method. [Background technology]

[0002] Patent Document 1 discloses a method of applying a voltage to an electrode for clamping a substrate embedded in an electrostatic chuck and determining the self-bias voltage Vdc from the current that flows at that time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 9,601,301 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique according to the present disclosure measures the in-plane distribution of the self-bias voltage of the substrate support. [Means for solving the problem]

[0005] One aspect of the present disclosure is a plasma processing apparatus comprising: a plasma processing chamber; a base disposed within the plasma processing chamber; an electrostatic chuck disposed on top of the base; a plurality of electrode layers disposed on the same plane within the electrostatic chuck; a switch group consisting of a plurality of switches electrically connected to each of the plurality of electrode layers; a power supply unit and a measurement unit electrically connected to the switch group; another switch that selects whether the switch group is connected to the power supply unit or the measurement unit; and a control unit, wherein the power supply unit includes a power supply that supplies power to the plurality of electrode layers, and the measurement unit includes a resistor and a voltmeter that measures a voltage across the resistor, and the control unit is configured to perform control including switching the switch group to the measurement unit and then switching the switch group to an on state one by one. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to measure the in-plane distribution of the self-bias voltage of the substrate support. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram illustrating a configuration example of a plasma processing system according to an embodiment. [Figure 2] 1 is a cross-sectional view showing a configuration example of a plasma processing apparatus according to an embodiment. [Figure 3] 10 is a graph showing the relationship between a bias voltage, a self-bias voltage, and a bias RF signal. [Figure 4] FIG. 2 is a plan view seen from above, illustrating an outline of divided regions of the electrostatic chuck according to the embodiment. [Figure 5] 1 is a cross-sectional view showing an outline of electrical connections in a substrate support part according to an embodiment; [Figure 6] 1 is a sequence chart showing an outline of a plasma processing method according to an embodiment. [Figure 7] 1 is a flowchart illustrating an outline of a plasma processing method according to an embodiment. [Figure 8] 3 is a cross-sectional view schematically showing the electrical relationship between a substrate, a ceramic member, and a heater element in a plasma processing method according to an embodiment. FIG. [Figure 9] 3 is an equivalent circuit diagram illustrating an electrical relationship between a substrate and a substrate support in a plasma processing method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the semiconductor device manufacturing process, various plasma processing steps are performed in which a plasma of a desired process gas is generated in a processing module containing a semiconductor wafer (hereinafter referred to as "substrate") to perform the desired processing on the substrate. As semiconductor devices become increasingly miniaturized, plasma processing that achieves a high aspect ratio is becoming increasingly important. To achieve a high aspect ratio, a method has been proposed in which ion energy is increased by increasing the bias voltage of the substrate support. However, increasing the bias voltage increases the likelihood of arcing and further impairs the stability and uniformity of the plasma. Therefore, to prevent arcing and improve the stability and uniformity of the plasma, it is desirable to constantly detect the self-bias voltage contained in the bias voltage and control the bias voltage. Furthermore, to predict the distribution of etching characteristics, it is desirable to measure the in-plane distribution of the self-bias voltage.

[0009] To address this issue, a method has been proposed in the past in which an electrode is provided inside the electrostatic chuck and the self-bias voltage is constantly monitored by measuring the voltage applied to the electrode. Also, Patent Document 1 discloses a method in which a voltage is applied to a clamping electrode and the self-bias voltage is calculated from the current that flows at that time.

[0010] However, conventional methods require a design change to install a new electrode inside the electrostatic chuck. Such a design change in an existing device is difficult due to the impact on temperature control using a heater or heat transfer medium. Furthermore, Patent Document 1 does not disclose a method for measuring the in-plane distribution of the self-bias voltage, and does not consider predicting the in-plane distribution of etching characteristics.

[0011] Therefore, the technology disclosed herein measures the in-plane distribution of the self-bias voltage of a substrate support. Specifically, a heater electrode layer including multiple heater elements is disposed inside an electrostatic chuck in the substrate support, and a measurement unit is provided to measure the voltage of each heater element. Furthermore, the voltage of each heater element is measured, and a calculation is performed to calculate the self-bias voltage in each region of the substrate support corresponding to each heater element based on the measured voltage.

[0012] The configuration of the plasma processing apparatus according to this embodiment will be described below with reference to the drawings. In this specification, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0013] <Plasma processing system> FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0014] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generating units may be used, including alternating current (AC) plasma generating units and direct current (DC) plasma generating units. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0015] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0016] <Plasma processing equipment> The following describes a configuration example of a capacitively coupled plasma processing apparatus 1 as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining the configuration example of the capacitively coupled plasma processing apparatus 1.

[0017] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms 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 showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0018] The substrate support 11 includes a main body 50 and a ring assembly 52. ​​The main body 50 has a central region 50a for supporting a substrate W and an annular region 50b for supporting the ring assembly 52. ​​A wafer is an example of a substrate W. The annular region 50b of the main body 50 surrounds the central region 50a of the main body 50 in a plan view. The substrate W is disposed on the central region 50a of the main body 50, and the ring assembly 52 is disposed on the annular region 50b of the main body 50 so as to surround the substrate W on the central region 50a of the main body 50. Therefore, the central region 50a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 50b is also referred to as a ring support surface for supporting the ring assembly 52.

[0019] In one embodiment, the main body 50 includes a base 60 and an electrostatic chuck 62. The base 60 includes a conductive member. The conductive member of the base 60 can function as a lower electrode. The electrostatic chuck 62 is disposed on the base 60. The electrostatic chuck 62 includes a ceramic member 64, an attraction electrode layer 66 disposed within the ceramic member 64, and a heater electrode layer 68. The heater electrode layer 68 is disposed on top of the attraction electrode layer 66. Details of the heater electrode layer 68 will be described later. The ceramic member 64 has a central region 50a. In one embodiment, the ceramic member 64 also has an annular region 50b. Note that another member surrounding the electrostatic chuck 62, such as an annular electrostatic chuck or an annular insulating member, may also have the annular region 50b. In this case, the ring assembly 52 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 62 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32 (described later) may be disposed within the ceramic member 64. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 60 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the attraction electrode layer 66 may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0020] The ring assembly 52 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0021] The substrate support 11 also includes a temperature adjustment module configured to adjust at least one of the electrostatic chuck 62, the ring assembly 52, and the substrate W to a target temperature. The temperature adjustment module may include a heater electrode layer 68, a heat transfer medium, a flow passage 70, or a combination thereof. A heat transfer fluid, such as brine or a gas, flows through the flow passage 70. In one embodiment, the flow passage 70 is formed in the base 60. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 50a.

[0022] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0023] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0024] 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) to at least one lower electrode and / or at least one upper electrode. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generating unit 12. In addition, a bias RF signal is supplied to the at least one lower electrode, thereby generating a bias voltage V B The bias voltage V B Details will be given later.

[0025] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0026] The second RF generating unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0027] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0028] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof. In one embodiment, a waveform generator for generating a sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0029] Here, the self-bias voltage V generated in the substrate support portion 11 dc As described above, when a source RF signal is supplied to the plasma processing apparatus 1, the gas introduced into the plasma processing space 10s is ionized into electrons and positive ions to form plasma PM. At this time, since the electrons have a small mass, they move within the plasma processing space 10s in response to the high-frequency voltage changes of the source RF signal and flow into the lower electrode, i.e., the substrate support 11. On the other hand, since the positive ions have a large mass, they cannot follow the high-frequency voltage changes of the source RF signal, and most of them remain in the plasma processing space 10s. As a result, the substrate support 11 is negatively charged with respect to the plasma processing space 10s. In this state, the voltage of the substrate support 11 is a self-bias voltage V dc is.

[0030] In one embodiment, a bias RF signal is applied to the lower electrode. Figure 3 shows the bias voltage V B1 is a graph showing an example of the amount of change per time of the bias voltage V B The dotted line indicates the self-bias voltage V dc The dashed line represents the bias RF signal voltage V rf In the example shown in Figure 3, the bias voltage V B is the self-bias voltage V dc and the bias RF signal voltage V rf That is, the bias RF signal voltage V rf is the self-bias voltage V dc The graph is offset in the negative direction by the bias voltage V B The graph is as follows.

[0031] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided 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 regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0032] Next, a detailed description will be given of the main body 50 of the substrate support 11. Fig. 4 is a plan view seen from above showing the outline of the configuration of the main body 50 of the substrate support 11 according to this embodiment.

[0033] 4, only the electrostatic chuck 62 is shown in the main body 50 of the substrate support 11. As described above, the electrostatic chuck 62 in the main body 50 includes the central region 50a and the annular region 50b. Of the circles shown by solid lines, the portion surrounded by the inner circle is the central region 50a, and the portion sandwiched between the inner and outer circles is the annular region 50b.

[0034] The central region 50a and the annular region 50b are divided into multiple regions. One of these multiple regions is referred to as a divided region 80. In the figure, the central region 50a and the annular region 50b are radially divided by dashed lines and concentric circles, and the hatched region is one of the divided regions 80 thus divided. All of the divided regions other than the hatched divided region 80 are also divided regions 80, but the hatching and symbols have been omitted for clarity. Note that "divided" refers to the division of a region for convenience, not to the actual separation of the region. Each divided region 80 is provided with one of the heater elements 100, which are multiple heater electrode layers included in the heater electrode layer 68. In this specification, to avoid duplication of names, each of the multiple heater electrode layers included in the heater electrode layer 68 is referred to as a heater element 100. In the figure, one heater element 100, indicated by a dotted line, is provided corresponding to each hatched divided region 80. Each of the heater elements 100 is one of the electrodes constituting part of the heater electrode layer 68. Each of the heater elements 100 is embedded in the electrostatic chuck 62 near the corresponding divided region 80, and all are provided on the same plane. Each of the heater elements 100 heats its corresponding divided region 80 when AC power is supplied to it. Only one of the heater elements 100 is shown in the figure; the other heater elements 100 corresponding to the other divided regions 80 are similar and therefore not shown. The shape of the divided region 80 is not limited to the example shown in the figure; the central region 50a and the annular region 50b may be divided into multiple regions of different shapes. In this case, only the central region 50a may be divided into multiple regions, and the annular region 50b may not be divided into multiple regions of different shapes. Furthermore, the shape of the heater elements 100 is not limited to the example shown in the figure, and the shape and number of the heater elements 100 may correspond to the shape and number of the divided regions 80 .

[0035] FIG. 5 is a partial cross-sectional view of the plasma processing apparatus 1, illustrating an outline of the electrical connection configuration in the substrate support 11. For clarity, components unnecessary for describing the electrical connection in the substrate support 11 are omitted. In this specification, "electrically connected" refers to a connection in which one component is connected to another component to form an electrical circuit. This connection may be a wired connection via a conductor or a wireless connection via electric or magnetic field coupling. This connection may be direct, i.e., without any additional components in between, or indirect, i.e., with additional components in between. Hereinafter, "electrically connected" may simply be referred to as "connected." Furthermore, a state in which one component is electrically connected to another component is defined as the "on" state of that component, and a state in which the component is not electrically connected is similarly defined as the "off" state. Furthermore, for components whose connection state can be switched on or off via a switch (described below), the state of the switch that turns the component on is defined as the "on" state of that switch, and the state of the switch that turns the component off is defined as the "off" state of that switch.

[0036] In FIG. 5 , each of the multiple heater elements 100 is electrically connected to a power supply unit 104 or a measurement unit 106 via a switch group consisting of multiple first switches 102. The first switches 102 are configured to switch each of the multiple heater elements 100 on or off relative to the power supply unit 104 or the measurement unit 106. In the example of FIG. 5 , only the first switch corresponding to the heater element 100 shown on the far right is on, and the first switches corresponding to all of the other heater elements 100 are off. In this way, the multiple first switches 102 can be used to turn all of the multiple heater elements 100 on or off, or to turn on a desired number of the multiple heater elements 100 and turn off the others. Specifically, the first switches 102 may be relays that can be switched on or off by the control unit 2 using an electrical signal.

[0037] The power supply unit 104 and the measurement unit 106 are electrically connected to the multiple heater elements 100 via a second switch 110. The second switch 110 is configured to be able to switch the power supply unit 104 and the measurement unit 106 for the multiple heater elements 100 on or off. In other words, the second switch selects and switches the connection destination of the multiple first switches to either the power supply unit 104 or the measurement unit 106. The second switch 110 can switch between turning the power supply unit 104 on and the measurement unit 106 off, turning the power supply unit 104 off and the measurement unit 106 on, or turning both off. In the example of FIG. 5, both the power supply unit 104 and the measurement unit 106 are off, which is a floating state. Specifically, the second switch 110 may be a relay that can be switched on or off by the control unit 2 using an electrical signal.

[0038] With the first switch 102 and the second switch 110, for example, all of the first switches 102 can be turned on simultaneously, and the second switch 110 can be used to turn on the power supply unit 104 and turn off the measurement unit 106, thereby connecting all of the heater elements 100 to the power supply unit 104. Also, for example, it is possible to connect only one of the heater elements 100 to the measurement unit 106 by turning on only one of the first switches 102 and turning off all of the other first switches 102, and using the second switch 110 to turn on the measurement unit 106 and turn off the power supply unit 104. In addition to the above, it is possible to connect any or all of the multiple heater elements 100 to any of the power supply units 104 and the measurement units 106 in a desired combination.

[0039] The power supply unit 104 includes a heater power supply 120 that supplies power to the heater electrode layer 68, and a heater control panel 122. The heater control panel 122 is configured to control the power supply from the heater power supply 120. For example, the control unit 2 may control the power supply from the heater power supply 120 via the heater control panel 122 using an electrical signal.

[0040] An RF filter 124 is provided between the power supply unit 104 and the plurality of first switches 102. During plasma generation, RF noise originating from the high-frequency power supplied from the RF power supply 31 may enter the power supply unit 104 through the heater electrode layer 68. If the RF noise reaches the heater power supply 120, it may impair the operation or performance of the heater power supply 120, or the efficiency of plasma generation may decrease due to high-frequency power consumption by the heater electrode layer 68. The RF filter 124 can protect the power supply unit 104 by attenuating or blocking the RF noise. For this reason, the RF filter 124 may be a known filter configured to attenuate or block AC current of a desired frequency, and may specifically include a coil, a capacitor, a resistor, or a combination thereof.

[0041] Measurement unit 106 includes RF filter 124, resistor 130, and voltmeter 132 that measures the voltage across resistor 130. RF filter 124 in measurement unit 106 removes the effects of RF noise from the voltage measured by voltmeter 132. That is, voltmeter 132 can measure a voltage from which RF noise has been removed. In addition, measurement unit 106 includes a desired configuration that can transmit the voltage measured by voltmeter 132 to control unit 2 and record each value.

[0042] <Plasma treatment method> Next, a description will be given of a plasma processing method MT that can be performed in the above-described plasma processing apparatus 1. In the plasma processing method MT, the self-bias voltage V of the substrate support member 11 during plasma generation is dc is calculated for each divided region 80. Specifically, by sequentially executing steps ST1 to ST9 described below, the heater elements 100 corresponding to each divided region 80 are connected to the measurement unit 106 one by one, and the voltage V2 is measured for each heater element 100. Subsequently, in step ST10, a calculation is performed based on the voltage V2, and the self-bias voltage V dc6 and 7 are a sequence chart (FIG. 6) and a flowchart (FIG. 7) showing an example of steps of a plasma processing method MT according to this embodiment.

[0043] In FIG. 6, "on" or "off" in (a) means whether RF power is supplied from the RF power supply 31 in a chronological order. "on" or "off" in (b) means whether power is supplied to the chucking electrode layer 66 as the lower electrode in a chronological order. "All on," "only one on," or "all off" in (c) means whether the first switches 102 are on or off in a chronological order. "Power supply unit on," "measurement unit on," or "floating" in (d) means whether the power supply unit 104 or the measurement unit 106 is on or both are off (floating) in the second switch in a chronological order. Note that when the power supply unit 104 is on, the measurement unit 106 is off, and when the measurement unit 106 is on, the power supply unit 104 is off.

[0044] 6 and 7, the plasma processing method MT is started with no RF power supplied, no power supplied to the attraction electrode layer 66, all first switches 102 turned off, and the second switches 110 floating. At the start, the substrate W is assumed to have been loaded into the plasma processing chamber 10 and placed on the substrate support 11.

[0045] In step ST1, a desired gas for plasma generation is supplied, followed by the supply of RF power. The RF power includes at least a source RF signal for plasma generation, and plasma PM is generated in the plasma processing space 10s. The RF power may also include a bias RF signal that attracts plasma ions to the substrate W. The bias RF signal may be supplied before, after, or simultaneously with the source RF signal.

[0046] In step ST2, power supply to the attraction electrode layer 66 is started. This causes the substrate W to be attracted to the upper surface 62a of the electrostatic chuck 62. After the substrate W is attracted, a heat transfer medium may be supplied to the gap between the back surface of the substrate W and the central region 50a.

[0047] In step ST3, power is supplied to the heater electrode layer 68. Specifically, all of the first switches 102 are turned on, and the second switches 110 turn on the power supply units 104. This connects all of the heater elements 100 to the power supply units 104, and AC power is supplied from the heater power supply 120 to all of the heater elements 100.

[0048] In step ST4, when one heater element 100 is turned on, the voltage V2 in the measurement unit 106 is measured. Specifically, of the multiple first switches 102 that were all turned on in step ST3, only one desired one is left on, and all the other first switches 102 are turned off. At the same time, the measurement unit 106 is turned on in the second switch 110. As a result, only one heater element 100 corresponding to the first switch 102 that was turned on is connected to the measurement unit 106. In the measurement unit 106, the voltage V2 applied to the resistor 130 is measured by the voltmeter 132.

[0049] In step ST5, power is supplied to the heater electrode layer 68. Specifically, this is the same as in step ST3.

[0050] In step ST6, when one heater element 100 whose voltage has not been measured is turned on, the voltage V2 is measured in the measurement unit 106. The one heater element 100 whose voltage has not been measured is a heater element 100 other than the one heater element 100 whose voltage V2 was measured in step ST4, and is a heater element 100 whose voltage V2 has not yet been measured even when step ST6 is repeatedly performed as described below. In step ST6, only the first switch 102 corresponding to the one heater element 100 whose voltage has not been measured is turned on, and all other first switches 102 are turned off. At the same time, the second switch 110 turns on the measurement unit 106. As a result, only the one heater element 100 whose voltage has not been measured is connected to the measurement unit 106. In the measurement unit 106, the voltage V2 across the resistor 130 is measured by the voltmeter 132. The heater element 100 whose voltage V2 was measured in step ST6 is not included in the heater elements 100 whose voltage has not been measured.

[0051] After step ST6 is performed, it is determined whether voltage measurement has been completed for all heater elements 100. If voltage measurement has not been completed for all heater elements 100 and there is one or more heater elements 100 whose voltage has not been measured, steps ST5 and ST6 are performed again. As a result, step ST6 is repeatedly performed, and the number of heater elements 100 whose voltage has not been measured decreases. When voltage measurement has finally been completed for all heater elements 100 and there are no heater elements 100 whose voltage has not been measured, the process proceeds to step ST7.

[0052] In step ST7, the first switch 102 turns off all the heater elements 100, and the second switch 110 turns off the power supply unit 104 and the measurement unit 106 (floating).

[0053] In step ST8, the supply of RF power is terminated. In step ST9, the surface of the electrostatic chuck 62 and the substrate W are neutralized, and then the supply of power to the attracting electrode layer 66 is terminated.

[0054] In step ST10, a self-bias voltage V is calculated for each divided region 80 based on the voltage V2 measured for each heater element 100. dc 6 and 7, step ST10 is executed after step ST9 is executed, and calculations are performed collectively based on the voltages V2 for all heater elements 100 acquired in steps ST4 and ST6, but this is not limiting. For example, step ST10 may be executed sequentially immediately after measuring the voltages V2 in steps ST4 and ST6. The calculation may be performed in the control unit 2 by having the measurement unit 106 transmit the value of the voltage V2 to the control unit 2.

[0055] The calculation performed in step ST10 will be described below with reference to Fig. 8 and Fig. 9. Fig. 8 is a cross-sectional view schematically showing the electrical relationship between the substrate W, the ceramic member 64, and the heater element 100 in steps ST4 and ST6. Fig. 9 is an equivalent circuit for the substrate W and the substrate support part 11 when an i-th heater element 100 (described later) is on and the measurement part 106 is on in steps ST4 and ST6.

[0056] 8, parasitic capacitances exist between the substrate W and the upper surface 62a of the electrostatic chuck 62 in the central region 50a, and between the upper surface 62a and the heater elements 100, and can be considered to be equivalent to capacitive elements. The electrostatic capacitance between the substrate W and the upper surface 62a of the electrostatic chuck 62 is denoted by C1, and the electrostatic capacitance between the upper surface 62a of the electrostatic chuck 62 and the heater elements 100 is denoted by C2. Here, when i heater elements 100 are provided, the electrostatic capacitance between the upper surface 62a of the electrostatic chuck 62 and the i-th heater element 100 is denoted by C 2i The capacitance C1 and the capacitance C 2i can be calculated as a fixed value from design parameters including the area, length (distance), and dielectric constant of each part of the substrate W, the upper surface 62a of the electrostatic chuck 62, the ceramic member 64, and the heater element 100.

[0057] In Figure 9, C1 and C 2i are the capacitances between the substrate W and the upper surface 62a of the electrostatic chuck 62, and between the upper surface 62a and the i-th heater element 100, respectively, as shown in FIG. 8. C3 is the capacitance when the RF filter 124 in the measurement unit 106 is considered equivalent to a capacitive element. R is the resistance value of the resistor 130. V0 is the sum of voltages in the equivalent circuit. V1 is the voltage between the substrate W and the heater electrode layer 68. V2 is the voltage measured by the voltmeter 132 in step ST4 or step ST6. Q1 is the charge accumulated between the substrate W and the upper surface 62a of the electrostatic chuck 62. Q 2i is the charge accumulated between the upper surface 62a of the electrostatic chuck 62 and the i-th heater element 100. Q3 is the charge accumulated in the RF filter 124.

[0058] Charges Q1 and Q2 in the equivalent circuit of Figure 9 2i , Q3, the following relationship holds according to the law of conservation of charge: Q1+Q 2i -Q3=0 Transform this into Q1+Q 2i =Q3 (1)

[0059] Charges Q1 and Q2 in the equivalent circuit of Figure 9 2i , Q3, voltages V1, V2 and capacitances C1, C 2i , C3, the following relationship holds: Q1+Q 2i =(C1+C 2i )V1···(2) Q3=C3V2 (3)

[0060] Substituting equations (2) and (3) into equation (1) gives equation (4) relating V1 and V2. (C1+C 2i )V1=C3V2 Transform this into V1=C3 / (C1+C 2i )·V2···(4)

[0061] The voltage V0 in the equivalent circuit of FIG. 9 is the sum of the voltages V1 and V2. V0=V1+V2 Substitute equation (4) into this. V0=C3 / (C1+C 2i )·V2+V2···(5)

[0062] Here, the voltage V0 is the voltage of the entire equivalent circuit of FIG. 9 when the i-th heater element 100 is turned on, and the self-bias voltage V of the divided region 80 corresponding to the i-th heater element 100 is dc From this and equation (5), V dc =C3 / (C1+C 2i )·V2+V2···(6)

[0063] According to equation (6), the self-bias voltage V of the divided area 80 corresponding to the i-th heater element 100 is dc can be expressed using the voltage V2 measured by the measurement unit 106. That is, in step ST10, the self-bias voltage V of the divided region 80 corresponding to the i-th heater element 100 is calculated based on the voltage V2 using equation (6). dc can be calculated.

[0064] In steps ST4 and ST6, the voltage V2 is measured for all the heater elements 100 from 1 to i. Therefore, in step ST10, the self-bias voltage V is measured for each of the divided regions 80 corresponding to all the heater elements 100 from 1 to i. dc can be calculated.

[0065] The above description shows the case where the i-th heater element 100 is located in the central region 50a of the substrate support 11 facing the substrate W. On the other hand, if the heater element 100 is located in the annular region 50b of the substrate support 11 facing the ring assembly 52, the self-bias voltage V dc8, the calculation of step ST10 is performed by setting the capacitance between the ring assembly 52 and the upper surface 62b of the electrostatic chuck 62 in the annular region 50b as C1, the voltage between the ring assembly 52 and the heater electrode layer 68 as V1, and the charge accumulated between the ring assembly 52 and the upper surface 62b of the electrostatic chuck 62 as Q1.

[0066] According to the above disclosure, the self-bias voltage V dc can be calculated based on the voltage V2 measured for each of the plurality of heater elements 100. Therefore, by using the substrate support 11 including the heater electrode layer 68 including the plurality of heater elements 100 inside the electrostatic chuck 62, the self-bias voltage V can be calculated without changing the design inside the electrostatic chuck 62. dc Furthermore, the in-plane distribution of the self-bias voltage V dc By using the in-plane distribution of the etching amount, the in-plane etching characteristics of the substrate W can be predicted.

[0067] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0068] For example, in this embodiment, the substrate support part 11 in the capacitively coupled plasma processing apparatus 1 is disclosed, but this is not limited to this, and the same effect can be obtained by configuring the substrate support part 11 in the inductively coupled plasma processing apparatus 1 in the same way.

[0069] In addition, for example, in steps ST4 and ST6, the plurality of heater elements 100 are turned on one by one and the voltage V2 is measured one by one, but this is not limited to this. dcare predicted to have similar values, the process may be performed by simultaneously turning on a plurality of heater elements 100 corresponding to the divided region 80 and turning off all other heater elements 100. In this case, the voltage V2 measured by the measurement unit 106 can be treated as the average value of the voltages V2 measured by turning on the heater elements 100 one by one and performing the process.

[0070] Furthermore, for example, although the measuring unit 106 is provided with the RF filter 124, the present invention is not limited to this. That is, instead of the RF filter 124, another component that can be regarded as equivalent to the capacitive element in the equivalent circuit in the example of Fig. 9 may be provided. In this case, the capacitance when the component is regarded as equivalent to the capacitive element can be set to C3, and the calculation of step ST10 can be performed.

[0071] Furthermore, for example, the components of the above-described embodiments can be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components of the combination, as well as other functions and effects that will be apparent to those skilled in the art from the description herein. Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology disclosed herein may provide other effects that will be apparent to those skilled in the art from the description herein, in addition to or in place of the above-described effects.

[0072] The following configurations also fall within the technical scope of the present disclosure. (1) a plasma processing chamber; a base disposed within the plasma processing chamber; an electrostatic chuck disposed on the upper part of the base; a plurality of electrode layers disposed in the same plane within the electrostatic chuck; a switch group including a plurality of switches electrically connected to the plurality of electrode layers, respectively; a power supply unit and a measurement unit electrically connected to the group of switches; another switch that selects the connection destination of the group of switches to either the power supply unit or the measurement unit; a control unit, the power supply unit includes a power supply that supplies power to the plurality of electrode layers; the measuring unit includes a resistor and a voltmeter that measures a voltage across the resistor; The control unit The control unit is configured to be able to execute control including switching the connection destination of the switch group to the measurement unit, and then switching the plurality of switches constituting the switch group to an on state one by one. Plasma processing equipment. (2) The plasma processing apparatus according to (1), wherein the measurement unit includes a capacitance element disposed between the power supply unit and the group of switches. (3) The plasma processing apparatus according to (1) or (2), wherein the electrode layer is a heater electrode layer. (4) The electrostatic chuck includes an attraction electrode layer; The plasma processing apparatus according to any one of (1) to (3), wherein the plurality of electrode layers are disposed above the attraction electrode layer. (5) The plasma processing apparatus according to any one of (1) to (4), wherein the group of switches is arranged inside the base. (6) The plasma processing apparatus according to (2), wherein the capacitive element constitutes an RF filter. (7) The plasma processing apparatus described in any one of (1) to (6), wherein the control unit is configured to be capable of executing control including switching the connection destination of the switch group to the power supply unit and switching all of the multiple switches constituting the switch group to an on state, then switching the connection destination of the switch group to the measurement unit, and then switching the multiple switches to an on state one by one. (8) A plasma processing method in a plasma processing apparatus, comprising: The plasma processing apparatus includes: a plasma processing chamber; a base disposed within the plasma processing chamber; an electrostatic chuck disposed on the upper part of the base; a plurality of electrode layers disposed in the same plane within the electrostatic chuck; a switch group including a plurality of switches electrically connected to the plurality of electrode layers, respectively; a power supply unit and a measurement unit electrically connected to the group of switches; another switch that selects the connection destination of the group of switches to either the power supply unit or the measurement unit; a control unit, the power supply unit includes a power supply that supplies power to the plurality of electrode layers; the measuring unit includes a resistor and a voltmeter that measures a voltage across the resistor; The plasma processing method includes: a first step of switching the connection destination of the switch group to the measurement unit, and then switching the plurality of switches constituting the switch group to an on state one by one; a second step of measuring a voltage in the measurement unit when one of the plurality of switches constituting the switch group is in an on state. (9) The power supply circuit further includes a step of switching the connection destination of the switch group to the power supply unit and switching all of the switches constituting the switch group to an on state, The plasma processing method according to (8), wherein the first step and the second step are performed after the step. (10) The plasma processing method according to (8) or (9), further comprising a step of calculating a self-bias voltage of an area corresponding to one of the plurality of switches in the substrate support part based on the voltage measured in the second step. [Explanation of symbols]

[0073] 1. Plasma processing equipment 2. Control section 60 Foundations 62 Electrostatic Chuck 68 heater electrode layer 100 heater element 102 First Switch 104 Power supply section 106 Measuring section 110 Second Switch 120 Heater power supply 130 Resistance 132 Voltmeter

Claims

1. a plasma processing chamber; a base disposed within the plasma processing chamber; an electrostatic chuck disposed on an upper portion of the base; A plurality of electrode layers disposed in the same plane within the electrostatic chuck; a switch group including a plurality of first switches electrically connected to the plurality of electrode layers, respectively; a power supply unit and a measurement unit electrically connected to the group of switches; a second switch that selects a connection destination of the group of switches to either the power supply unit or the measurement unit; A control unit, the power supply unit includes a power supply that supplies power to the plurality of electrode layers; The measurement unit includes a resistor and a voltmeter that measures a voltage across the resistor. The control unit is controlling the voltmeter to measure a voltage across the resistor while turning on one of the first switches in the switch group, turning off all of the first switches in the switch group except for the first switch in the on state, and electrically connecting a destination of the first switch in the on state to the measurement unit via the second switch; Plasma processing equipment.

2. The plasma processing apparatus according to claim 1 , wherein the measurement unit includes a capacitive element disposed between the power supply unit and the group of switches.

3. 3. The plasma processing apparatus according to claim 1, wherein the electrode layer is a heater electrode layer.

4. The electrostatic chuck includes an attraction electrode layer, The plasma processing apparatus according to claim 1 , wherein the plurality of electrode layers are disposed above the attraction electrode layer.

5. The plasma processing apparatus according to claim 1 , wherein the group of switches is disposed inside the base.

6. The plasma processing apparatus according to claim 2 , wherein the capacitive element constitutes an RF filter.

7. the control unit calculates a self-bias voltage of a region of the electrostatic chuck corresponding to one of the first switches based on a measurement value of the voltage across the resistor.

3. The plasma processing apparatus according to claim 1 or 2.

8. the control unit turns one of the first switches in the switch group to an on state and turns all of the first switches in the switch group except for the first switch in the on state to an off state; turning on all the first switches of the switch group and electrically connecting the connection destinations of the first switches in the on state to the power supply unit by the second switches.

3. The plasma processing apparatus according to claim 1 or 2.

9. The control unit turns one of the first switches in the switch group to an on state, and turns all of the first switches in the switch group except for the first switch in the on state to an off state; 9. The plasma processing apparatus according to claim 8, further comprising: a step of turning on all of the first switches in the switch group and electrically connecting the connection destinations of the first switches in the on state to the power supply unit by the second switches, the step being repeated in sequence.

10. A plasma processing method in a plasma processing apparatus, comprising: The plasma processing apparatus includes: a plasma processing chamber; a base disposed within the plasma processing chamber; an electrostatic chuck disposed on an upper portion of the base; A plurality of electrode layers disposed in the same plane within the electrostatic chuck; a switch group including a plurality of first switches electrically connected to the plurality of electrode layers, respectively; a power supply unit and a measurement unit electrically connected to the group of switches; a second switch that selects a connection destination of the group of switches to either the power supply unit or the measurement unit; A control unit, the power supply unit includes a power supply that supplies power to the plurality of electrode layers; The measurement unit includes a resistor and a voltmeter that measures a voltage across the resistor. The plasma processing method includes: a first step of turning on one of the first switches in the switch group, turning off all of the first switches in the switch group except for the first switch in the on state, and electrically connecting a connection destination of the first switch in the on state to the measurement unit by a second switch; a second step of measuring the voltage across the resistor with the voltmeter.

11. a third step of turning on all of the first switches constituting the switch group and electrically connecting a connection destination of the first switches in the on state to the power supply unit by a second switch; The plasma processing method according to claim 10 , wherein the third step is performed before or after the first step and the second step.

12. 12. The plasma processing method according to claim 10, further comprising a step of calculating a self-bias voltage of a region of the electrostatic chuck corresponding to one of the plurality of first switches based on the voltage measured in the second step.

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