Plasma processing apparatus and electrostatic chuck

Abstract

To provide a plasma processing apparatus and an electrostatic chuck that suppress abnormal discharge.SOLUTION: In a substrate support part that is arranged within a plasma processing chamber, an electrostatic chuck comprises: a ceramic member 1111a that has a substrate support surface 111a and a rear surface 1111f; a chuck electrode layer 1111b that is arranged under the substrate support surface within the ceramic member; a bias electrode layer 1111d that is arranged under the chuck electrode layer; and a gas diffusion channel that extends under the bias electrode layer in a horizontal direction. The gas diffusion channel is composed of a main path 214 and a plurality of branch paths 215 that are branched from the main path, and has a gas inlet which extends from a ceramic member rear surface to the gas diffusion channel in a longitudinal direction and a plurality of gas outlets 216 which communicate with the gas diffusion channel, and the gas outlet has a gas diffusion channel 218 and a cavity part 217 having a ceramic porous material inserted.SELECTED DRAWING: Figure 5

Description

Technical Field

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[0001] The present disclosure relates to a plasma processing apparatus and an electrostatic chuck.

Background Art

[0002] Patent Document 1 discloses an electrostatic chuck for use in a substrate processing chamber, comprising a plate having a first surface and a second surface facing the first surface, a first electrode embedded in the plate close to the first surface, a second electrode embedded in the plate close to the second surface, a plurality of conductive elements connecting the first electrode to the second electrode, a first gas channel disposed in the plate and between the first electrode and the second electrode, a gas inlet extending from the second surface of the plate to the first gas channel, and a plurality of gas outlets extending from the first surface of the plate to the first gas channel.

[0003] Patent Document 2 discloses an electrostatic chuck comprising a dielectric, an electrode embedded in the dielectric, and a dielectric insert disposed at an outlet of a gas conduit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] On one side, the present disclosure provides a plasma processing apparatus and an electrostatic chuck that suppress abnormal discharge.

Means for Solving the Problems

[0006] To solve the above problems, according to one embodiment, a plasma processing chamber and a substrate support portion disposed within the plasma processing chamber, wherein the substrate support portion comprises a ceramic member having a substrate support surface and a back surface, a chuck electrode layer disposed below the substrate support surface within the ceramic member, a bias electrode layer disposed below the chuck electrode layer within the ceramic member, and a gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel comprises a main path and a plurality of branch paths branching from the main path, and within the ceramic member A substrate support portion comprising: a gas inlet extending vertically from the back surface to the gas diffusion channel; a plurality of gas outlets communicating with the gas diffusion channel, each gas outlet having a cavity portion extending horizontally from at least one of the plurality of branch paths and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with ceramic porous material; a heat transfer gas supply portion configured to supply heat transfer gas to the gas inlet; a DC power supply configured to apply a DC voltage to the chuck electrode layer; and a bias power supply configured to apply a sequence of voltage pulses to the bias electrode layer. The aforementioned cavity portion has a vertical dimension of less than 180 μm. A plasma processing device is provided. [Effects of the Invention]

[0007] In one respect, it is possible to provide a plasma processing apparatus and an electrostatic chuck that suppress abnormal discharge. [Brief explanation of the drawing]

[0008] [Figure 1] An example of a diagram illustrating the configuration of a capacitively coupled plasma processing apparatus. [Figure 2] A diagram illustrating RF pulse signals and DC pulse signals. [Figure 3] An example of a top view of an electrostatic chuck. [Figure 4] An example of a cross-sectional view of the main body of the circuit board support. [Figure 5] An example of a magnified cross-sectional view of the main body of the substrate support. [Figure 6] An example of a top view of an electrostatic chuck, magnified near the gas outlet. [Figure 7] Another example of a top view of an electrostatic chuck, magnified near the gas outlet. [Figure 8] Another example of a magnified top view of an electrostatic chuck near the gas outlet. [Figure 9] Another example of a cross-sectional view of the main body of the circuit board support. [Modes for carrying out the invention]

[0009] Various exemplary embodiments will be described in detail below with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals.

[0010] [Plasma Processing System] The following describes an example of the configuration of a plasma processing system. Figure 1 is an example of a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus 1.

[0011] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is located inside the plasma processing chamber 10. The shower head 13 is located above the substrate support unit 11. In one embodiment, the shower head 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 shower head 13, the side walls 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 10s. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support portion 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0012] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region 111a for supporting the substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan view. The substrate W is placed on the central region 111a of the main body portion 111, and the ring assembly 112 is placed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. Therefore, the central region 111a is also called the substrate support surface for supporting the substrate W, and the annular region 111b is also called the ring support surface for supporting the ring assembly 112.

[0013] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is placed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a, a chuck electrode layer 1111b disposed within the ceramic member 1111a, an annular chuck electrode layer 1111c disposed within the ceramic member 1111a, a bias electrode layer 1111d disposed within the ceramic member 1111a, and an annular bias electrode layer 1111e disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b.

[0014] The chuck electrode layer 1111b is located within the central region 111a of the ceramic member 1111a. The plasma processing apparatus 1 includes a DC power supply 15 configured to apply a DC voltage to the chuck electrode layer 1111b. The chuck electrode layer 1111b is coupled to the DC power supply 15. The annular chuck electrode layer 1111c is located within the annular region 111b of the ceramic member 1111a. The plasma processing apparatus 1 includes a DC power supply 16 configured to apply a DC voltage to the annular chuck electrode layer 1111c. The annular chuck electrode layer 1111c is coupled to the DC power supply 16. Although the chuck electrode layers 1111b and 1111c are shown as examples of unipolar electrodes, they may also be bipolar electrodes. Other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may also have an annular region 111b. In this case, the ring assembly 112 may be placed on an annular electrostatic chuck or an annular insulating member, or it may be placed on both the electrostatic chuck 1111 and the annular insulating member.

[0015] The bias electrode layer 1111d is disposed within the central region 111a of the ceramic member 1111a and is disposed below the chuck electrode layer 1111b (on the side away from the substrate support surface). The annular bias electrode layer 1111e is disposed within the annular region 111b of the ceramic member 1111a and is disposed below the annular chuck electrode layer 1111c (on the side away from the substrate support surface). The bias electrode layer 1111d and the annular bias electrode layer 1111e are each coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32, which will be described later. The bias electrode layer 1111d and the annular bias electrode layer 1111e are also referred to as RF / DC electrodes. In this case, the bias electrode layer 1111d and the annular bias electrode layer 1111e function as lower electrodes. A bias RF signal and / or a DC signal, which will be described later, is supplied to the bias electrode layer 1111d and the annular bias electrode layer 1111e. Note that the conductive members of the base 1110 and the bias electrode layer 1111d and the annular bias electrode layer 1111e may function as a plurality of lower electrodes. Also, the chuck electrode layer 1111b and the annular chuck electrode layer 1111c may function as lower electrodes. Therefore, the substrate support portion 11 includes at least one lower electrode.

[0016] The ring assembly 112 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 ring is formed of a conductive material or an insulating material, and the cover ring is formed of an insulating material.

[0017] Further, the substrate support portion 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate W to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. Further, the substrate support portion 11 may include a heat transfer gas supply portion 17 configured to supply a heat transfer gas to the gap between the back surface of the substrate W and the central region 111a. The heat transfer gas supply portion 17 is configured to supply a heat transfer gas (e.g., He gas) to a communication path 200 formed in the electrostatic chuck 1111.

[0018] The shower head 13 is configured to introduce at least one process gas from the gas supply portion 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The process 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 plurality of gas introduction ports 13c. Further, the shower head 13 includes at least one upper electrode. Note that the gas introduction portion may include, in addition to the shower head 13, one or more side gas injection portions (SGI: Side Gas Injector) attached to one or more openings formed in the side wall 10a.

[0019] 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 processing gas to the shower head 13 from a corresponding gas source 21 via a 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 that modulate or pulse the flow rate of at least one processing gas.

[0020] 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 plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, 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. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, and ionic components in the formed plasma can be drawn into the substrate W.

[0021] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a, a second RF generation unit 31b, and an RF generator (bias power supply) 31c. The first RF generation 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 generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. One or more generated source RF signals are supplied to at least one lower electrode and / or at least one upper electrode. The RF generator 31c is configured to generate an RF signal (a sequence of RF pulse signals).

[0022] The second RF generation unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is 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 generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. One or more generated 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.

[0023] 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 generation unit 32a, a second DC generation unit 32b, and a DC generator (bias power supply) 32c. In one embodiment, the first DC generation unit 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to at least one lower electrode. In one embodiment, the second DC generation unit 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 at least one upper electrode. The DC generator 32c is configured to generate a DC signal (a sequence of DC pulse signals).

[0024] In various embodiments, at least one of 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 pulse waveform. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses from a DC signal is connected between the first DC generation unit 32a and at least one lower electrode. Thus, the first DC generation unit 32a and the waveform generation unit constitute a voltage pulse generation unit. When the second DC generation unit 32b and the waveform generation unit constitute a voltage pulse generation unit, the voltage pulse generation unit is connected to at least one upper electrode. The voltage pulses may have positive or negative polarity. The sequence of voltage pulses may also include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. The first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, and the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0025] The exhaust system 40 may be connected to, for example, a gas outlet 10e 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 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.

[0026] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described herein. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform the 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 is implemented, for example, by a computer 2a. The processing unit 2a1 may be configured to perform various control operations by reading a program from the storage unit 2a2 and executing the read program. This program may be stored in the storage unit 2a2 in advance, or it may be obtained via a medium when needed. The obtained program is stored in the storage unit 2a2 and read from the storage unit 2a2 and executed by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or it may be a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The memory unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).

[0027] Hereinafter, the pulsed RF signal supplied to the upper or lower electrode will be referred to as the "RF signal." The pulsed DC signal applied to the lower electrode will be referred to as the "DC signal." In the following explanation, the pulsed RF signal is supplied to the lower electrode; however, it may also be supplied to the upper electrode.

[0028] [RF signal / DC signal] Figure 2 is a diagram illustrating RF signals and DC signals. In the following diagram, RF signals will be abbreviated as "RF" and DC signals as "DC". In the following explanation, the RF signal will be explained using a pulsed source RF signal as an example. The source RF signal is the RF signal used for plasma generation. In Figure 2, the horizontal axis represents time, the vertical axis for RF represents the power level, and the vertical axis for DC represents the voltage level.

[0029] In one embodiment, the RF signal and DC signal are ON from time t0 to time t1, and OFF from time t1 to time t2, repeating this ON / OFF state as one cycle. The pulse frequency F1 of the RF signal and DC signal is in the range of 1kHz to 50kHz. In the illustrated example, the ON and OFF states of the DC signal are synchronized with the ON and OFF states of the RF signal, but this is not limited to this. For example, the ON state of the DC signal may be offset from the ON state of the RF signal, and the duration of the ON state of the DC signal may differ from the ON state of the RF signal.

[0030] In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz while in the ON state and a zero power level while in the OFF state. The DC signal has a sequence of voltage pulses PS1 while in the ON state. The sequence of voltage pulses PS1 alternates between an ON state (negative polarity voltage level) and an OFF state (zero voltage level) in a second pulse period (pulse frequency F2). That is, the sequence of voltage pulses PS1 has a pulse frequency F2 that is greater than the pulse frequency F1. In one embodiment, the pulse frequency F2 is in the range of 100 kHz to 1 MHz. In another embodiment, the pulse frequency F2 is in the range of 300 kHz to 600 kHz.

[0031] The DC signal has a sequence of voltage pulses PS1 having a first voltage level while in the off state and a second voltage level while in the on state. The absolute value of the second voltage level is greater than the absolute value of the first voltage level. In one embodiment, the first voltage level has a zero voltage level, the second voltage level has a negative polarity, and the sequence of voltage pulses PS1 repeats the zero voltage level and the negative voltage level at a pulse frequency F2.

[0032] Thus, the RF generator 31c and / or DC generator 32c, acting as bias power supplies, apply a sequence of voltage pulses (for example, the RF pulse signal and / or DC pulse signal shown in Figure 2) to the bias electrode layer 1111d and the annular bias electrode layer 1111e, which serve as lower electrodes.

[0033] [Electrostatic Chuck 1111] Next, the electrostatic chuck 1111 will be explained further. Figure 3 is an example of a top view of the electrostatic chuck 1111. Figure 4 is an example of a cross-sectional view of the main body 111 of the substrate support part 11. Figures 5(a) and 5(b) are examples of partially enlarged cross-sectional views of the main body 111 of the substrate support part 11.

[0034] As shown in Figure 4, the ceramic member 1111a of the electrostatic chuck 1111 has a substrate support surface (central region 111a) for supporting the substrate W and a ring support surface (annular region 111b) for supporting the ring assembly 112. The ceramic member 1111a also has a back surface 1111f, which is the surface opposite to the substrate support surface and the ring support surface (the lower surface in Figure 4). The chuck electrode layer 1111b is located within the central region 111a of the ceramic member 1111a, below the substrate support surface. The bias electrode layer 1111d is located within the central region 111a of the ceramic member 1111a, below the chuck electrode layer 1111b. The annular chuck electrode layer 1111c is located within the annular region 111b of the ceramic member 1111a, below the ring support surface. The annular bias electrode layer 1111e is positioned below the annular chuck electrode layer 1111c within the annular region 111b of the ceramic member 1111a.

[0035] Furthermore, the ceramic member 1111a of the electrostatic chuck 1111 has a communication passage 200 through which the heat transfer gas supplied from the heat transfer gas supply unit 17 (see Figure 1) flows. The communication passage 200 includes, for example, communication passages 210, 220, 230, and 240.

[0036] The connecting passage 210 has a gas inlet 211, a gas diffusion channel 212, and a plurality of gas outlets 216. The gas diffusion channel 212 also has an introduction portion 213, an annular portion 214, and a plurality of branching portions 215.

[0037] The gas inlet 211 is formed within the ceramic member 1111a, extending vertically from the back surface 1111f of the ceramic member 1111a to the gas diffusion channel 212. The heat transfer gas supply unit 17 (see Figure 1) is configured to supply heat transfer gas to the gas inlet 211 formed on the back surface 1111f of the ceramic member 1111a.

[0038] The gas diffusion channel 212 is located within the ceramic member 1111a, below the bias electrode layer 1111d. The gas diffusion channel 212 is formed extending horizontally. The introduction portion 213 has one end communicating with the gas inlet 211 and the other end communicating with the annular portion 214. The annular portion 214 is formed in a substantially ring shape concentric with the center of the electrostatic chuck 1111. The introduction portion 213 and the annular portion 214 are also referred to as the main path (main part) of the gas diffusion channel 212. Multiple branched portions 215 are formed branching from the annular portion 214. One end of each branched portion 215 communicates with the annular portion 214 (main path) and the other end communicates with the gas outlet 216. The branched portions 215 are also referred to as branched paths. Thus, the gas diffusion channel 212 has a main path and multiple branched paths branching from the main path.

[0039] The gas outlet 216 has one end communicating with the gas diffusion channel 212 and the other end communicating with the space facing the substrate support surface (the space between the back surface of the substrate W supported by the substrate support surface and the substrate support surface). The gas outlet 216 has a cavity portion 217 and a porous portion 218. The cavity portion 217 extends horizontally from at least one of the multiple branch portions 215. The porous portion 218 extends vertically from the cavity portion 217 to the substrate support surface (central region 111a) and is filled with ceramic porous material. The porous portion 218 also extends vertically from a position lower than the lower surface of the bias electrode layer 1111d to the substrate support surface (central region 111a). The porous portion 218 is formed so that heat transfer gas can flow from the cavity portion 217 to the space facing the substrate support surface. Furthermore, the porous portion 218 shortens the distance in the voltage application direction (vertical direction, up and down direction) of the space through which the heat transfer gas can flow within the porous portion 218. This suppresses abnormal discharge of the heat transfer gas, as will be described later.

[0040] The porous portion 218 may be formed, for example, by placing a mixture of ceramic material and resin material in a hole that will become a gas outlet 216 formed in the ceramic member 1111a before sintering, and then sintering the ceramic member 1111a. The electrostatic chuck 1111 may also be formed by laminating a thin plate-shaped ceramic material that will become the ceramic member 1111a, a conductive material that will become the electrode layers (chuck electrode layer 1111b, annular chuck electrode layer 1111c, bias electrode layer 1111d, annular bias electrode layer 1111e), and a mixture of ceramic material and resin material that will become the porous portion 218, and then sintering them.

[0041] Figure 6 is an example of a top view of the electrostatic chuck 1111, magnified near the gas outlet 216. In Figure 6, the position where the bias electrode layer 1111d is located is clearly indicated by a dot pattern.

[0042] The bias electrode layer 1111d, which is placed inside the ceramic member 1111a, is formed in a substantially disc shape. Furthermore, the bias electrode layer 1111d has an opening 1111d1 that avoids the position where the gas outlet 216 is formed.

[0043] Furthermore, the introduction portion 213 and the annular portion 214, which are the main paths of the gas diffusion channel 212, are positioned below the bias electrode layer 1111d in a plan view. When a sequence of voltage pulses is applied to the base 1110, which functions as the lower electrode, and the bias electrode layer 1111d, the base 1110 and the bias electrode layer 1111d become at the same potential. That is, because the base 1110, which is positioned below the main path (introduction portion 213, annular portion 214), and the bias electrode layer 1111d, which is positioned above the main path (introduction portion 213, annular portion 214), are at the same potential, no vertical potential difference occurs in the main path (introduction portion 213, annular portion 214). In other words, abnormal discharge within the introduction portion 213 and the annular portion 214 can be suppressed.

[0044] On the other hand, the gas outlet 216 is positioned to pass through the opening 1111d1 of the bias electrode layer 1111d. As a result, a potential difference is generated in the vertical direction between the substrate W supported by the substrate support surface and the base 1110 which functions as the lower electrode. Due to this potential difference, there is a risk of abnormal discharge occurring in the gas outlet 216 when the substrate W is subjected to plasma treatment.

[0045] In contrast, the gas outlet 216 is provided with a porous portion 218, which allows for the passage of heat transfer gas while shortening the mean free path of ionized electrons in the vertical direction. This suppresses abnormal discharge within the gas outlet 216.

[0046] Furthermore, the gas outlet 216 has a cavity 217 below the porous portion 218. As a result, the heat transfer gas supplied from the heat transfer gas supply unit 17 to the gas inlet 211 flows into the cavity 217 via the introduction portion 213, the annular portion 214, and the branching portion 215. The heat transfer gas then flows into the porous portion 218 from the lower side of the porous portion 218 facing the cavity 217 and into the space facing the substrate support surface (the space between the back surface of the substrate W supported by the substrate support surface and the substrate support surface). This makes it possible to increase the conductance of the communication passage 210.

[0047] Furthermore, the vertical dimension H1 of the cavity portion 217 and the vertical dimension H2 of the branch portion 215 are less than 180 μm. This suppresses abnormal discharge in the cavity portion 217. The vertical dimension is also called the height dimension or the voltage gradient direction between the substrate W and the base 1110.

[0048] In one embodiment, the vertical dimension H1 of the cavity portion 217 and the vertical dimension H2 of the branch portion 215 are 50 μm or more. This makes it possible to increase the conductance of the connecting passage 210.

[0049] In one embodiment, the vertical dimension H1 of the cavity portion 217 is the same as the vertical dimension H2 of the branch portion 215, as shown in Figure 5(a).

[0050] Note that the vertical dimension H1 of the hollow portion 217 may be different from the vertical dimension H2 of the branch portion 215. In one embodiment, the vertical dimension H1 of the hollow portion 217 is smaller than the vertical dimension H2 of the branch portion 215, as shown in Figure 5(b).

[0051] Furthermore, the vertical dimension H2 of the branch section 215 is smaller than the vertical dimension H3 of the annular section 214, which is the main path. This allows for an increase in the flow path cross-sectional area of ​​the main path, thereby increasing the conductance of the connecting passage 210.

[0052] Furthermore, the plasma processing apparatus 1 can increase the pressure of the heat transfer gas while suppressing abnormal discharge within the heat transfer gas communication passage 210. This improves the heat transfer between the substrate W and the main body 111. Therefore, even if the bias voltage is increased and the heat input from the plasma to the substrate W increases, the substrate W can be cooled effectively. Also, if the plasma processing apparatus 1 is a device that performs plasma etching, increasing the bias voltage improves the verticality and productivity during the etching process.

[0053] Similarly, as shown in Figure 3, the communication passage 220 has a gas inlet 221, a gas diffusion channel 222, and a plurality of gas outlets 226. The gas diffusion channel 222 has an introduction portion 223, an annular portion 224, and a plurality of branching portions 225. The communication passage 230 has a gas inlet 231, a gas diffusion channel 232, and a plurality of gas outlets 236. The gas diffusion channel 232 has an introduction portion 233, an annular portion 234, and a plurality of branching portions 235. The communication passage 240 has a gas inlet 241, a gas diffusion channel 242, and a plurality of gas outlets 246. The gas diffusion channel 242 has an introduction portion 243, an annular portion 244, and a plurality of branching portions 245. The communication passages 220, 230, and 240 are the same as the communication passage 210, and redundant explanations are omitted.

[0054] The communication passage 200 is not limited to the configuration shown in Figures 2 and 3. For example, the back surface 1111f of the ceramic member 1111a may have one gas inlet, and the gas inlet may branch off midway to supply heat transfer gas to each of the gas diffusion channels 212, 222, 232, and 242. Alternatively, the electrostatic chuck 1111 may have one main path formed, for example, in a spiral shape, from which multiple branch paths branch off and communicate with their respective gas outlets.

[0055] Although the description assumes that the cavity portion 217 of the gas outlet 216 extends horizontally from one branch portion 215, it is not limited to this configuration.

[0056] The cavity portion 217 of the gas outlet 216 may extend horizontally from at least two of the multiple branching paths. Figure 7 is another example of a top view of the electrostatic chuck 1111 magnified near the gas outlet 216. The gas outlet 216 extends horizontally from three branching portions 215a, 215b, and 215c to form the cavity portion 217 (see Figure 5). This can increase the conductance of the branching portion 215.

[0057] Figure 8 is yet another example of a top view of the electrostatic chuck 1111, magnified near the gas outlet 216. Furthermore, a cavity portion 217 (see Figure 5) is formed extending horizontally from a branch portion 215 (branch path) communicating with the annular portion 214 (main path) of one gas diffusion channel 212 and from a branch portion 229 (other branch path) communicating with the annular portion 224 (other main path) of another gas diffusion channel 222. This makes it possible to increase the conductance of the communication passage 200.

[0058] Figure 9 is another example of a cross-sectional view of the main body 111 of the substrate support 11. The heat transfer gas communication passage 200 may be provided on the ring support surface. The communication passage 250 has a second gas inlet (not shown), a second gas diffusion channel, and a plurality of second gas outlets 256. The second gas diffusion channel has a second introduction portion (second main path), a second annular portion (second main path) 254, and a plurality of second branch portions (second branch paths) 255. The second gas outlet 256 has a second cavity portion 257 and a second porous portion 258.

[0059] The second gas inlet (not shown) of the communication passage 250 is formed within the ceramic member 1111a, extending vertically from the back surface 1111f of the ceramic member 1111a to the second gas diffusion channel. The heat transfer gas supply unit 17 (see Figure 1) is configured to supply heat transfer gas to the second gas inlet formed on the back surface 1111f of the ceramic member 1111a.

[0060] The second gas diffusion channel is located within the ceramic member 1111a, below the annular bias electrode layer 1111e. The second gas diffusion channel is formed extending horizontally. One end of the second introduction portion communicates with the second gas inlet, and the other end communicates with the second annular portion 254. The second annular portion 254 is formed in a substantially ring shape concentric with the center of the electrostatic chuck 1111. The second introduction portion and the second annular portion 254 are also referred to as the second main path (or second main part) of the second gas diffusion channel. Multiple second branch portions 255 are formed by branching from the second annular portion 254. One end of the second branch portion 255 communicates with the second annular portion 254 (second main path), and the other end communicates with the second gas outlet 256. The second branch portion 255 is also referred to as the second branch path. Thus, the second gas diffusion channel has a second main pathway and a plurality of second branch pathways branching off from the second main pathway.

[0061] The second gas outlet 256 has one end communicating with the second gas diffusion channel and the other end communicating with the space facing the ring support surface (the space between the back surface of the edge ring supported by the ring support surface and the ring support surface). The second gas outlet 256 has a second cavity portion 257 and a second porous portion 258. The second cavity portion 257 extends horizontally from at least one of the plurality of second branch portions 255. The second porous portion 258 extends vertically from the second cavity portion 257 to the ring support surface (annular region 111b) and is filled with ceramic porous material. The second porous portion 258 also extends vertically from a position lower than the lower surface of the annular bias electrode layer 1111e to the ring support surface (annular region 111b). The second porous portion 258 is formed to allow heat transfer gas to flow from the second cavity portion 257 to the space facing the ring support surface. Furthermore, the second porous portion 258 shortens the distance in the voltage application direction (vertical direction, up and down direction) of the space through which the heat transfer gas can flow within the second porous portion 258. This suppresses abnormal discharge of the heat transfer gas, as will be described later.

[0062] Furthermore, the second gas outlet 256 has a second cavity portion 257 located below the second porous portion 258. As a result, the heat transfer gas supplied from the heat transfer gas supply unit 17 to the second gas inlet flows into the second cavity portion 257 via the second introduction portion, the second annular portion 254, and the second branching portion 255. The heat transfer gas then flows into the second porous portion 258 from the lower side of the second porous portion 258 facing the second cavity portion 257, and into the space facing the ring support surface (the space between the back surface of the edge ring supported by the ring support surface and the ring support surface). This increases the conductance of the communication passage 250.

[0063] Furthermore, the vertical dimensions of the second cavity portion 257 and the second branch portion 255 are less than 180 μm. This makes it possible to suppress abnormal discharge in the second cavity portion 257.

[0064] In one embodiment, the vertical dimensions of the second cavity portion 257 and the second branch portion 255 are 50 μm or more. This makes it possible to increase the conductance of the communication passage 250.

[0065] In one embodiment, the vertical dimension of the second cavity portion 257 is the same as the vertical dimension of the second branch portion 255.

[0066] The vertical dimension of the second cavity portion 257 may differ from the vertical dimension of the second branch portion 255. In one embodiment, the vertical dimension of the second cavity portion 257 is smaller than the vertical dimension of the second branch portion 255.

[0067] Furthermore, the vertical dimension of the second branch section 255 is smaller than the vertical dimension of the second annular section 254, which is the second main path. This increases the flow path cross-sectional area of ​​the second main path and increases the conductance of the connecting passage 250.

[0068] The embodiments disclosed above include, for example, the following aspects: (Note 1) Plasma processing chamber and The substrate support portion is disposed within the plasma processing chamber, and the substrate support portion is A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, A plurality of gas outlets communicating with the gas diffusion channel, each gas outlet having a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with ceramic porous material, A substrate support section, A heat transfer gas supply unit configured to supply heat transfer gas to the aforementioned gas inlet, A DC power supply configured to apply a DC voltage to the chuck electrode layer, The system comprises a bias power supply configured to apply a sequence of voltage pulses to the bias electrode layer, Plasma processing equipment. (Note 2) The aforementioned cavity portion has a vertical dimension of less than 180 μm. The plasma processing apparatus described in Appendix 1. (Note 3) The aforementioned cavity portion has the same vertical dimension as the corresponding branch path. A plasma processing apparatus as described in Appendix 1 or Appendix 2. (Note 4) The branch path has a vertical dimension smaller than the vertical dimension of the main path. A plasma processing apparatus as described in any one of the items 1 to 3 of the appendix. (Note 5) The porous portion extends from a position lower than the bias electrode layer to the substrate support surface. A plasma processing apparatus as described in any one of the items 1 through 4 of the appendix. (Note 6) The aforementioned cavity extends horizontally from at least two of the plurality of branch paths. A plasma processing apparatus as described in any one of the items 1 through 5 of the appendix. (Note 7) The substrate support portion further includes other gas diffusion channels extending horizontally within the ceramic member and below the bias electrode layer, The other gas diffusion channel has another main path and a plurality of other branch paths branching off from the other main path. The aforementioned cavity extends horizontally from at least one of the plurality of other branch paths. A plasma processing apparatus as described in any one of the items 1 through 5 of the appendix. (Note 8) The ceramic member further has a ring support surface, The substrate support portion is, At least one edge ring is disposed on the ring support surface so as to surround the substrate on the substrate support surface, Within the ceramic member, at least one annular chuck electrode layer is disposed below the ring support surface, The ceramic member includes an annular bias electrode layer disposed below at least one annular chuck electrode layer, A plasma processing apparatus as described in any one of the items 1 through 5 of the appendix. (Note 9) The substrate support portion is, A second gas diffusion channel extending horizontally within the ceramic member and below the annular bias electrode layer, the second gas diffusion channel having a second main path and a plurality of second branch paths branching from the second main path, A plurality of second gas outlets communicating with the second gas diffusion channel, each second gas outlet having a second cavity portion extending horizontally from at least one of the plurality of second branch paths, and a second porous portion extending vertically from the second cavity portion to the ring support surface and filled with ceramic porous material, The plasma processing apparatus described in Appendix 8. (Note 10) The second cavity portion has a vertical dimension of less than 180 μm. The plasma processing apparatus described in Appendix 9. (Note 11) An electrostatic chuck used in a plasma processing apparatus, A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, The gas outlets are in communication with the gas diffusion channel, and each gas outlet has a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface, which is filled with a ceramic porous material. Electrostatic chuck. (Note 12) The aforementioned cavity portion has a vertical dimension of less than 180 μm. The electrostatic chuck described in Appendix 11. (Note 13) The aforementioned cavity portion has the same vertical dimension as the corresponding branch path. The electrostatic chuck described in Appendix 11 or Appendix 12. (Note 14) The branch path has a vertical dimension smaller than the vertical dimension of the main path. An electrostatic chuck as described in any one of the items in Appendix 11 to Appendix 13. (Note 15) The porous portion extends from a position lower than the bias electrode layer to the substrate support surface. An electrostatic chuck as described in any one of the items in Appendix 11 to Appendix 14. (Note 16) The aforementioned cavity extends horizontally from at least two of the plurality of branch paths. An electrostatic chuck as described in any one of the items in Appendix 11 to Appendix 15. (Note 17) The ceramic member further includes other gas diffusion channels extending horizontally within the ceramic member and below the bias electrode layer, The other gas diffusion channel has another main path and a plurality of other branch paths branching off from the other main path. The aforementioned cavity extends horizontally from at least one of the plurality of other branch paths. An electrostatic chuck as described in any one of the items in Appendix 11 to Appendix 15.

[0069] It should be noted that the present invention is not limited to the configurations shown in the above embodiments, including combinations with other elements. These aspects can be modified without departing from the spirit of the present invention and can be appropriately determined according to their application. [Explanation of Symbols]

[0070] 1. Plasma processing equipment 11. Substrate support section 15 DC power supply 16 DC power supply 17 Heat transfer gas supply unit 31c RF generator (bias power supply) 32C DC generator (bias power supply) 111 Main body 111a Central area (board support surface) 111b Annular region (ring support surface) 112 Ring Assembly 1110 base 1111 Electrostatic Chuck 1111a Ceramic component 1111b Chuck electrode layer 1111c Annular Chuck Electrode Layer 1111d bias electrode layer 1111d1 Aperture 1111e Annular bias electrode layer 1111f Back side H1 Vertical dimension 200, communication path 210,220,230,240,250 Communication path 211 Gas Inlet 212 Gas diffusion channels 213 Introduction (Main Route) 214 Circular section (main path) 215 Branching section (branching route) 216 Gas outlet 217 Hollow part 218 Porous portion 254 Second Circular Section (Second Main Path) 255 Second branching point (second branching route) 256 Second gas outlet 257 Second cavity 258 Second porous section

Claims

1. Plasma processing chamber and The substrate support portion is located within the plasma processing chamber, and the substrate support portion is A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, A plurality of gas outlets communicating with the gas diffusion channel, each gas outlet having a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with ceramic porous material, A substrate support section, A heat transfer gas supply unit configured to supply heat transfer gas to the aforementioned gas inlet, A DC power supply configured to apply a DC voltage to the chuck electrode layer, The system comprises a bias power supply configured to apply a sequence of voltage pulses to the bias electrode layer, The aforementioned cavity portion has a vertical dimension of less than 180 μm. Plasma processing equipment.

2. The aforementioned cavity portion has the same vertical dimension as the corresponding branch path. The plasma processing apparatus according to claim 1.

3. The branch path has a vertical dimension smaller than the vertical dimension of the main path. The plasma processing apparatus according to claim 2.

4. Plasma processing chamber and The substrate support portion is located within the plasma processing chamber, and the substrate support portion is A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, A plurality of gas outlets communicating with the gas diffusion channel, each gas outlet having a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with ceramic porous material, A substrate support section, A heat transfer gas supply unit configured to supply heat transfer gas to the aforementioned gas inlet, A DC power supply configured to apply a DC voltage to the chuck electrode layer, The system comprises a bias power supply configured to apply a sequence of voltage pulses to the bias electrode layer, The aforementioned cavity extends horizontally from at least two of the plurality of branch paths. Plasma processing equipment.

5. Plasma processing chamber and The substrate support portion is located within the plasma processing chamber, and the substrate support portion is A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, A plurality of gas outlets communicating with the gas diffusion channel, each gas outlet having a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with ceramic porous material, A substrate support section, A heat transfer gas supply unit configured to supply heat transfer gas to the aforementioned gas inlet, A DC power supply configured to apply a DC voltage to the chuck electrode layer, The system comprises a bias power supply configured to apply a sequence of voltage pulses to the bias electrode layer, The substrate support portion further includes other gas diffusion channels extending horizontally within the ceramic member and below the bias electrode layer, The other gas diffusion channel has another main path and a plurality of other branch paths branching off from the other main path. The aforementioned cavity extends horizontally from at least one of the plurality of other branch paths. Plasma processing equipment.

6. Plasma processing chamber and The substrate support portion is located within the plasma processing chamber, and the substrate support portion is A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, A plurality of gas outlets communicating with the gas diffusion channel, each gas outlet having a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with ceramic porous material, A substrate support section, A heat transfer gas supply unit configured to supply heat transfer gas to the aforementioned gas inlet, A DC power supply configured to apply a DC voltage to the chuck electrode layer, The system comprises a bias power supply configured to apply a sequence of voltage pulses to the bias electrode layer, The ceramic member further has a ring support surface, The substrate support portion is, At least one edge ring is disposed on the ring support surface so as to surround the substrate on the substrate support surface, Within the ceramic member, at least one annular chuck electrode layer is disposed below the ring support surface, The ceramic member includes an annular bias electrode layer disposed below at least one annular chuck electrode layer, The substrate support portion is, A second gas diffusion channel extending horizontally within the ceramic member and below the annular bias electrode layer, the second gas diffusion channel having a second main path and a plurality of second branch paths branching from the second main path, A plurality of second gas outlets communicating with the second gas diffusion channel, each second gas outlet having a second cavity portion extending horizontally from at least one of the plurality of second branch paths, and a second porous portion extending vertically from the second cavity portion to the ring support surface and filled with ceramic porous material, comprising a plurality of second gas outlets, Plasma processing equipment.

7. The second cavity portion has a vertical dimension of less than 180 μm. The plasma processing apparatus according to claim 6.

8. The porous portion extends from a position lower than the bias electrode layer to the substrate support surface. A plasma processing apparatus according to any one of claims 1 to 7.

9. An electrostatic chuck used in a plasma processing apparatus, A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, The gas outlets are in communication with the gas diffusion channel, and each gas outlet has a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with a ceramic porous material. The aforementioned cavity portion has a vertical dimension of less than 180 μm. Electrostatic chuck.

10. The aforementioned cavity portion has the same vertical dimension as the corresponding branch path. The electrostatic chuck according to claim 9.

11. The branch path has a vertical dimension smaller than the vertical dimension of the main path. The electrostatic chuck according to claim 10.

12. An electrostatic chuck used in a plasma processing apparatus, A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, The gas outlets are in communication with the gas diffusion channel, and each gas outlet has a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with a ceramic porous material. The aforementioned cavity extends horizontally from at least two of the plurality of branch paths. Electrostatic chuck.

13. An electrostatic chuck used in a plasma processing apparatus, A ceramic member having a substrate support surface and a back surface, Within the ceramic member, a chuck electrode layer is disposed below the substrate support surface, Within the ceramic member, a bias electrode layer is disposed below the chuck electrode layer, A gas diffusion channel extending horizontally within the ceramic member and below the bias electrode layer, wherein the gas diffusion channel has a main path and a plurality of branch paths branching from the main path, Within the ceramic member, a gas inlet extends vertically from the back surface to the gas diffusion channel, The gas outlets are in communication with the gas diffusion channel, and each gas outlet has a cavity portion extending horizontally from at least one of the plurality of branch paths, and a porous portion extending vertically from the cavity portion to the substrate support surface and filled with a ceramic porous material. The ceramic member further includes other gas diffusion channels extending horizontally within the ceramic member and below the bias electrode layer, The other gas diffusion channel has another main path and a plurality of other branch paths branching off from the other main path. The aforementioned cavity extends horizontally from at least one of the plurality of other branch paths. Electrostatic chuck.

14. The porous portion extends from a position lower than the bias electrode layer to the substrate support surface. The electrostatic chuck according to any one of claims 9 to 13.

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