JP2023112675A - Substrate support and plasma processing apparatus - Google Patents

Abstract

To provide a substrate support and a plasma processing apparatus enabling improvement of efficiency of a low frequency side of bias electric power.SOLUTION: A substrate support is arranged in a processing container, and includes: an electrostatic chuck that is formed of dielectric material and has a first support surface for supporting a substrate, and includes, inside the electrostatic chuck, a first electrode and a second electrode in order from the first support surface side; and a base supporting the electrostatic chuck. The second electrode is arranged at a position where distance from the second electrode to the first support surface is equal to or less than distance from the second electrode to the base. A voltage for attracting the substrate is applied to the first electrode, and bias electric power is supplied to the second electrode.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to substrate supports and plasma processing apparatuses.

2. Description of the Related Art Conventionally, an electrostatic chuck that performs electrostatic attraction is used to hold a substrate in a plasma processing apparatus. An electrode for electrostatic chucking is provided in the electrostatic chuck, and the substrate on the electrostatic chuck is chucked by applying a voltage to the electrode from a DC power supply. Further, in the plasma processing apparatus, for example, a high-frequency power source is connected to a substrate supporting a dielectric film of an electrostatic chuck in order to supply bias power (Patent Document 1). In order to supply bias power, for example, an inner peripheral electrode and an outer peripheral electrode are provided inside the dielectric film, and a high frequency power source is connected to the inner peripheral electrode and the outer peripheral electrode (Patent Document 2). .

U.S. Patent Application Publication No. 2019/0295823 U.S. Patent Application Publication No. 2019/0237300

The present disclosure provides a substrate support and a plasma processing apparatus that can improve the efficiency of bias power on the low frequency side.

A substrate support part according to one aspect of the present disclosure is a substrate support part that is arranged in a processing container and includes a first support surface that supports a substrate, and a first electrode in order from the first support surface side. and a second electrode inside, the electrostatic chuck formed of a dielectric, and a base for supporting the electrostatic chuck, wherein the second electrode is a distance from the first support surface is arranged at a position below the distance to the base, a voltage for attracting the substrate is applied to the first electrode, and a bias power is supplied to the second electrode.

According to the present disclosure, the efficiency of bias power on the low frequency side can be improved.

FIG. 1 is a diagram showing an example of a plasma processing apparatus according to the first embodiment of the present disclosure. FIG. 2 is a diagram showing an example of an equivalent circuit of an electrostatic chuck and plasma in the present embodiment and reference example. FIG. 3 is a diagram showing an example of experimental results of bias power supply. FIG. 4 is a diagram showing an example of experimental results of bias power supply. FIG. 5 is a diagram showing an example of experimental results of the etching process. FIG. 6 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically insulated. FIG. 7 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically insulated according to Modification 1. FIG. FIG. 8 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 2. In FIG. FIG. 9 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 3. In FIG. FIG. 10 is a diagram showing an example of an image of each potential on the base, the bias electrode, and the substrate. FIG. 11 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 4. In FIG. 12A and 12B are diagrams showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 5. FIG. 13A and 13B are diagrams showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 6. FIG. FIG. 14 is a partial cross-sectional view showing an example of an electrostatic chuck according to the second embodiment. FIG. 15 is a cross-sectional view showing an example of an electrostatic electrode in plan view. FIG. 16 is a cross-sectional view showing an example of the first layer of the bias electrode in plan view. FIG. 17 is a cross-sectional view showing an example of the second layer of the bias electrode in plan view. FIG. 18 is a cross-sectional view showing an example of the third layer of the bias electrode in plan view. FIG. 19 is a cross-sectional view showing an example of a supply layer to an electrostatic electrode in plan view. FIG. 20 is a diagram showing an example of the sheath potential near the ring assembly in the second embodiment. FIG. 21 is a diagram showing an example of experimental results in the second embodiment.

Embodiments of the disclosed substrate supporting portion and plasma processing apparatus will be described in detail below with reference to the drawings. Note that the disclosed technology is not limited by the following embodiments.

When a high frequency power supply is connected to the base to supply bias power, it is conceivable to increase the voltage (Vpp) on the substrate in order to improve the etching rate. However, in the circuit from the high-frequency power supply to the upper electrode through the plasma, the series voltage component due to the capacitance between the base and the heater electrode in the electrostatic chuck does not contribute to the improvement of Vpp on the substrate. It consumes power unnecessarily. Furthermore, in the circuit, the voltage of the bias power supplied to the base increases, and the breakdown voltage required for each member of the circuit also increases. In particular, when the frequency of the bias power is low, the influence becomes large. Therefore, it is expected to lower the voltage of the bias power supplied to the base and improve the efficiency of the bias power on the low frequency side.

(First embodiment)
[Configuration of plasma processing system]
A configuration example of the plasma processing system will be described below. FIG. 1 is a diagram showing an example of a plasma processing apparatus according to the first embodiment of the present disclosure. As shown in FIG. 1, the plasma processing system includes an inductively coupled plasma processing apparatus 1 and a controller 2 . That is, the inductively coupled plasma processing apparatus 1 is an ICP (Inductively Coupled Plasma) type plasma processing apparatus. The inductively coupled plasma processing apparatus 1 includes a plasma processing chamber 10 , a gas supply section 20 , a power supply 30 and an exhaust system 40 . Plasma processing chamber 10 is an example of a processing vessel and includes a dielectric window. The plasma processing apparatus 1 also includes a substrate supporting portion 11 , a gas introduction portion, and an antenna 14 . A substrate support 11 is positioned within the plasma processing chamber 10 . Antenna 14 is positioned on or above plasma processing chamber 10 (ie, on or above dielectric window 101). The plasma processing chamber 10 has a plasma processing space 10 s defined by a dielectric window 101 , sidewalls 102 of the plasma processing chamber 10 and the substrate support 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 exhaust port for exhausting gas from the plasma processing space. Plasma processing chamber 10 is grounded.

The substrate support portion 11 includes a body portion 111 and a ring assembly 112 . The body portion 111 has a central region 111 a for supporting the substrate W and an annular region 111 b for supporting the ring assembly 112 . A wafer is an example of a substrate W; The annular region 111b of the body portion 111 surrounds the central region 111a of the body portion 111 in plan view. The substrate W is arranged on the central region 111 a of the main body 111 , and the ring assembly 112 is arranged on the annular region 111 b of the main body 111 so as to surround the substrate W on the central region 111 a of the main body 111 . Accordingly, the central region 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as a ring support surface for supporting the ring assembly 112. FIG. Also, the central region 111a is an example of a first support surface, and the annular region 111b is an example of a second support surface.

In one embodiment, the body portion 111 includes a base 1110 , an electrostatic chuck 1111 and an adhesive layer 1112 . Base 1110 includes a conductive member. An electrostatic chuck 1111 is arranged on the base 1110 with an adhesive layer 1112 interposed therebetween. The electrostatic chuck 1111 includes a ceramic member 1111a, electrostatic electrodes 1111b and 1111d, a heater electrode 1111c, and bias electrodes 33 and 34 arranged in the ceramic member 1111a. Ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the annular region 111b. In this case, the ring assembly 112 may be placed on the annular electrostatic chuck or the annular insulating member, or may be placed on both the electrostatic chuck 1111 and the annular insulating member.

The electrostatic electrode 1111b is an electrode for attracting the substrate W placed on the central region 111a. The electrostatic electrode 1111d is an electrode for attracting the ring assembly 112 placed on the annular region 111b. A voltage for attracting the substrate W or the ring assembly 112 is applied to the electrostatic electrodes 1111b and 1111d from a DC power supply (not shown). The heater electrode 1111c is an example of a heater forming part of a temperature control module, which will be described later. The bias electrodes 33 and 34 are examples of at least one RF/DC electrode coupled to an RF (Radio Frequency) power supply 31 and/or a DC (Direct Current) power supply 32, which will be described later. Note that the conductive member of the base 1110 and at least one RF/DC electrode may function as a plurality of bias electrodes. Also, the electrostatic electrode 1111b may function as a bias electrode. Accordingly, substrate support 11 includes at least one bias electrode.

In the ceramic member 1111a, the central region 111a includes an electrostatic electrode 1111b, a bias electrode 33, and a heater electrode 1111c in this order from the central region 111a side. That is, the bias electrode 33 is arranged between the electrostatic electrode 1111b and the heater electrode 1111c. Also, in the annular region 111b, an electrostatic electrode 1111d and a bias electrode 34 are provided in order from the annular region 111b side. Note that the electrostatic electrode 1111d may be two or more electrodes when the ring assembly 112 is attracted with a bipolar force. Also, the electrostatic electrode 1111d may not be provided if the ring assembly 112 is not attracted. Here, the bias electrode 33 is arranged at a position where the distance to the upper surface of the central region 111 a is equal to or less than the distance to the upper surface of the base 1110 . More preferably, the bias electrode 33 is arranged at a position where the distance to the upper surface of the central region 111 a is shorter than the distance to the upper surface of the base 1110 . Similarly, the bias electrode 34 is arranged at a position where the distance to the upper surface of the annular region 111b is equal to or less than the distance to the upper surface of the base 1110. FIG. More preferably, the bias electrode 34 is arranged at a position where the distance to the upper surface of the annular region 111 b is shorter than the distance to the upper surface of the base 1110 .

The bias electrodes 33 and 34 are connected via an electrical path composed of a conductor in the ceramic member 1111a and a conductor 81a in the insulating sleeve 81 provided in the through-hole 80 of the base 1110, to the second electrode 34, which will be described later. is connected to the RF generator 31b of the . The electrostatic electrode 1111b is an example of a first electrode, and the bias electrode 33 is an example of a second electrode. Also, the electrostatic electrode 1111d is an example of a third electrode, and the bias electrode 34 is an example of a fourth electrode. That is, the third electrode is at least one electrode, and may be two or more electrodes in the case of bipolar chucking. Further, the electrostatic electrode 1111d may be integrated with the electrostatic electrode 1111b, and the bias electrode 34 and the bias electrode 33 may be integrated.

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 made of a conductive material or an insulating material, and the cover ring is made of an insulating material.

Also, the substrate supporter 11 may include a temperature control module configured to control 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 electrode 1111c, a heat transfer medium, a channel 1110a, or a combination thereof. A heat transfer fluid, such as brine or gas, flows through flow path 1110a. In one embodiment, channels 1110 a are formed in base 1110 and one or more heaters are positioned in ceramic member 1111 a of electrostatic chuck 1111 . The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to the gap between the back surface of the substrate W and the central region 111a.

The gas introduction section is configured to introduce at least one processing gas from the gas supply section 20 into the plasma processing space 10s. In one embodiment, the gas introduction includes a Center Gas Injector (CGI) 13 . The central gas injection part 13 is arranged above the substrate support part 11 and attached to a central opening formed in the dielectric window 101 . The central gas injection part 13 has at least one gas supply port 13a, at least one gas channel 13b, and at least one gas introduction port 13c. The processing gas supplied to the gas supply port 13a passes through the gas flow path 13b and is introduced into the plasma processing space 10s from the gas introduction port 13c. In addition to or instead of the central gas injection part 13, the gas introduction part is one or more side gas injectors (SGI: Side Gas Injector) attached to one or more openings formed in the side wall 102. may include

Gas supply 20 may include at least one gas source 21 and at least one flow controller 22 . In one embodiment, gas supply 20 is configured to supply at least one process gas from a respective gas source 21 via a respective flow controller 22 to the gas introduction. Each flow controller 22 may include, for example, a mass flow controller or a pressure controlled flow controller. Additionally, gas supply 20 may include one or more flow modulation devices that modulate or pulse the flow of at least one process gas.

Power supply 30 includes an RF power supply 31 coupled to plasma processing chamber 10 via at least one impedance match circuit. RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one bias electrode 33 , 34 and antenna 14 . Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Accordingly, RF power source 31 may function as at least part of a plasma generator configured to generate a plasma from one or more process gases in plasma processing chamber 10 . Further, by supplying a bias RF signal to at least one bias electrode 33, 34, a bias potential is generated in the substrate W, and ions in the formed plasma can be drawn into the substrate W. FIG.

In one embodiment, the RF power supply 31 includes a first RF generator 31a and a second RF generator 31b. The first RF generator 31a is coupled to the antenna 14 and configured to generate a source RF signal (source RF power) for plasma generation via at least one impedance matching circuit. In one embodiment, the source RF signal has a frequency within the range of 10 MHz to 150 MHz. In one embodiment, the first RF generator 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are provided to antenna 14 .

The second RF generator 31b is coupled to the at least one bias electrode 33, 34 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 within the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. One or more bias RF signals generated are provided to at least one bias electrode 33,34. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

Power supply 30 may also include a DC power supply 32 coupled to plasma processing chamber 10 . The DC power supply 32 includes a bias DC generator 32a. In one embodiment, the bias DC generator 32a is connected to at least one bias electrode 33, 34 and configured to generate a bias DC signal. The generated bias DC signal is applied to at least one bias electrode 33,34.

In various embodiments, the bias DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one bias electrode 33,34. The voltage pulse may have a rectangular, trapezoidal, triangular, sawtooth, or combination thereof pulse shape. That is, the bias DC signal may be a square wave, a trapezoidal wave, a triangle wave, a sawtooth wave, or a pulse wave of any combination thereof. In one embodiment, a waveform generator for generating a sequence of voltage pulses from the DC signal is connected between the bias DC generator 32a and the at least one bias electrode 33,34. Therefore, the bias DC generator 32a and the waveform generator constitute a voltage pulse generator. The voltage pulse may have a positive polarity or a negative polarity. Also, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses in one cycle. The bias DC generator 32a may be provided in addition to the RF power supply 31, or may be provided instead of the second RF generator 31b.

Antenna 14 includes one or more coils. In one embodiment, antenna 14 may include an outer coil and an inner coil that are coaxially arranged. In this case, the RF power supply 31 may be connected to both the outer coil and the inner coil, or may be connected to either one of the outer coil and the inner coil. In the former case, the same RF generator may be connected to both the outer and inner coils, or separate RF generators may be separately connected to the outer and inner coils.

The exhaust system 40 may be connected to a gas outlet 10e provided at the bottom of the plasma processing chamber 10, for example. 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. Vacuum pumps may include turbomolecular pumps, dry pumps, or combinations thereof.

Controller 2 processes computer-executable instructions that cause plasma processing apparatus 1 to perform the various steps described in this disclosure. Controller 2 may be configured to control elements of plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the controller 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 by, for example, a computer 2a. Processing unit 2a1 can be configured to perform various control operations by reading a program from storage unit 2a2 and executing the read program. This program may be stored in the storage unit 2a2 in advance, or may be acquired via a medium when necessary. The acquired program is stored in the storage unit 2a2, 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 may be 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 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 apparatus 1 via a communication line such as a LAN (Local Area Network).

[Equivalent circuit near electrostatic chuck]
Next, an equivalent circuit of a circuit through which a bias RF signal flows will be described with reference to FIG. FIG. 2 is a diagram showing an example of an equivalent circuit of an electrostatic chuck and plasma in the present embodiment and reference example. In FIG. 2, the bias RF signal supplied to the bias electrode is represented by _VRF , and the AC (Alternating Current) power of the heater power supplied to the heater electrode 1111c is represented by _VH . Note that FIG. 2 will be described using the bias electrode 33 as an example of the bias electrode.

An equivalent circuit 60 shown in FIG. 2 represents a case where a bias RF signal is supplied to the base 1110h in the conventional substrate support portion which is a reference example. In the equivalent circuit 60, the bias RF signal passes through the capacitance 61 between the base 1110h and the heater electrode 1111h, and then passes through the electrostatic electrode 1111g, the substrate W, and the plasma to the ground (GND). 62 and a path 63 branching to the heater power supply side and flowing to the ground (GND). In other words, the equivalent circuit 60 requires a wasted Vpp corresponding to the divided voltage in the capacitance 61 . In other words, in the equivalent circuit 60, the more current flows through the plasma, the more current flows through the path 63, and the impedance of the capacitance 61 causes a potential difference between the base 1110h and the heater electrode 1111h.

An equivalent circuit 64 shown in FIG. 2 represents a case where a bias RF signal is supplied to the bias electrode 33 in the substrate support section 11 of this embodiment. In the equivalent circuit 64, the bias RF signal is routed through the bias electrode 33, the electrostatic electrode 1111b, the substrate W, and the plasma to the ground (GND), and a path 65 branching from the bias electrode 33 and passing through the heater electrode 1111c. and a path 66 flowing to the ground (GND) on the heater power supply side. In the substrate supporting portion 11, the bias electrode 33 is brought closer to the electrostatic electrode 1111b, thereby reducing the impedance between the bias electrode 33 and the electrostatic electrode 1111b. Further, since the path 66 on the heater electrode 1111c side and the path 65 on the plasma side form a parallel circuit, the potentials of the heater electrode 1111c and the bias electrode 33 can be substantially the same and no potential difference occurs. In other words, it works favorably for withstand voltage design. Note that even if the heater electrode 1111c is not located below the bias electrode 34, the impedance between the bias electrode 34 and the electrostatic electrode 1111d can be reduced.

[Experimental result]
First, the potential of each part when 10 Vpp is applied to the bases 1110 and 1110h or the bias electrode 33 in the conventional substrate support part as a reference example and the substrate support part 11 of the present embodiment will be described. In the bases 1110 and 1110h, the voltage was 10.2 V in the reference example and 9.4 V in the present embodiment. The heater electrodes 1111c and 1111h were 6.4 V in the reference example and 8.6 V in the present embodiment. For the substrate W, the reference example was 2.9V and the present embodiment was 7.2V. For the edge ring of ring assembly 112, the reference was 2.4V and the present embodiment was 4.6V. It can be seen that the potential difference between the base 1110 and the heater electrode 1111c is smaller in this embodiment than in the reference example.

Next, a simulation was performed in which these results were applied when a bias RF signal was supplied so that the substrate W had a potential of 10 kVpp (400 kHz). In this case, in the reference example, it is necessary to supply a bias RF signal so that the base 1110h has a potential of 35 kV. On the other hand, in this embodiment, it is necessary to supply the bias RF signal so that the bias electrode 33 has a potential of 13 kV. That is, it is possible to set the potential of the substrate W to the same potential as in the conventional case with a bias RF signal that has a potential smaller than that of the reference example (about 40%). Also, the potential of the heater electrodes 1111c and 1111h is 22 kV in the reference example, whereas it is 12 kV in this embodiment, which is about 54%.

Next, results of experiments using the plasma processing apparatus 1 will be described with reference to FIGS. 3 to 5. FIG. 3 and 4 are diagrams showing an example of experimental results of bias power supply. Graph 70 shown in FIG. 3 is a reference example and a present embodiment when the pressure in the plasma processing chamber 10 is 15 mTorr (2.0 Pa), a 27 MHz source RF signal of 2500 W, and a 400 kHz bias RF signal of up to 500 W are supplied. 4 shows the potential (Vpp) between the base 1110h or the bias electrode 33 and the heater electrodes 1111c and 1111h in the embodiment of the form. 3 and 4, the bias electrode 33 of the embodiment is shown as a base for easy comparison. As shown in graph 70, in the reference example, there is a large difference between the potential of the base 1110h and the potential of the heater electrode 1111h, and a potential difference of about 800 V is generated when a bias RF signal of 250 W is supplied. On the other hand, in this embodiment, even when a bias RF signal of 500 W is supplied, almost no potential difference occurs between the bias electrode 33 and the heater electrode 1111c. Further, in this embodiment, when the power of the source RF signal is the same as in the reference example, the potentials of the base 1110 and the heater electrode 1111c are lower than in the reference example. Furthermore, as shown in the graph 71 of FIG. 4, the current I in the base 1110h or the bias electrode 33 also flows 3.3 Arms when a bias RF signal of 250 W is supplied in the reference example, and the bias RF signal 3.5 Arms is flowing when 500 W is supplied.

Next, the voltage and etching rate of each part in the reference example and the example of the present embodiment will be described with reference to FIG. FIG. 5 is a diagram showing an example of experimental results of the etching process. In table 72 shown in FIG. 5, the source RF signal is denoted as source power and the bias RF signal is denoted as bias power. In addition, in Table 72, the voltage of the bias electrode 33 of the example is represented as the voltage of the base for easy comparison. As shown in Table 72, for example, when 2500 W of 27 MHz source power and 200 W of 400 kHz bias power are supplied, the voltage of the base 1110 (bias electrode 33) changes from 1735 V in the reference example to 434 V in the embodiment by 25 V. % can be lowered. Also, the potential of the heater electrode 1111c at this time can be lowered by 47% from 861 V in the reference example to 407 V in the embodiment. Furthermore, the etching rate at this time can be improved from 1104 nm/min in the reference example to 1235 nm/min in the example, up to 112%. Similarly, when the combination of the source power and the bias power is 800 W/50 W, 800 W/200 W, and 2500 W/50 W, the voltage of the base 1110 (bias electrode 33) is lowered and etching is performed. rate can be improved.

Similarly, for example, when 2500 W of 27 MHz source power and 900 W of 13 MHz bias power are supplied, the voltage of the base 1110 (bias electrode 33) is reduced from 392 V in the reference example to 220 V in the example, which is 56%. be able to. Further, the potential of the heater electrode 1111c at this time can also be lowered by 95% from 15 V in the reference example to 14 V in the embodiment. Furthermore, the etching rate at this time can be improved from 1998 nm/min in the reference example to 2012 nm/min in the example, up to 101%. Similarly, when the combination of the source power and the bias power is 800 W/900 W, the voltage of the base 1110 (bias electrode 33) can be lowered and the etching rate can be improved. In this manner, the substrate supporting portion 11 of the present embodiment can improve the efficiency of the bias power on the low frequency side.

[Connection to bias electrode]
Next, the details of the connection from the second RF generator 31b to the bias electrode will be described with reference to FIG. FIG. 6 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically insulated. In the following description, the bias electrode 33 is used as an example of the bias electrode, and the electrostatic electrode 1111b and the heater electrode 1111c are omitted. Also, in FIG. 6, the base 1110 is assumed to be a conductive member. As shown in FIG. 6, an insulating sleeve 81 is provided in the through hole 80 of the base 1110, and a socket terminal 82 for power supply, a power supply line 83, and a joint terminal 84 are provided in the insulating sleeve 81. there is The socket terminal 82, the feeder line 83 and the joint terminal 84 are examples of the conductor 81a. Socket terminal 82 is secured to insulating sleeve 81 with adhesive 85 . Also, the upper portion of the socket terminal 82 and the joint terminal 84 are connected by a feeder line 83 . The junction terminal 84 is joined to the terminal 33 a of the bias electrode 33 . A cable (not shown) is connected to the socket terminal 82, and the cable is connected to the second RF generator 31b. In addition, the through-hole 80 is arranged so as to avoid the flow path 1110 a of the base 1110 . In the example of connection to the bias electrode 33 shown in FIG. 6, the base 1110 and the bias electrode 33 are electrically insulated by the ceramic member 1111a and the insulating sleeve 81 .

[Modification 1]
In the above embodiment, the power supply line 83 is used in the insulating sleeve 81 for connection to the bias electrode 33, but the socket terminal 82 may be joined to the terminal 33a of the bias electrode 33. will be described as Modified Example 1. Note that the plasma processing apparatus in Modification 1 is the same as that of the above-described embodiment, so redundant descriptions of the configuration and operation thereof will be omitted.

FIG. 7 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically insulated according to Modification 1. FIG. In FIG. 7, the base 1110 is assumed to be a conductive member. As shown in FIG. 7, an insulating sleeve 81 is provided in the through hole 80 of the base 1110, and a socket terminal 82a for power supply is provided in the insulating sleeve 81. As shown in FIG. The socket terminal 82a is an example of the conductor 81a. The socket terminal 82a is fixed to the insulating sleeve 81 with an adhesive 85a. Also, the upper portion of the socket terminal 82 a is joined to the terminal 33 a of the bias electrode 33 . A cable (not shown) is connected to the lower portion of the socket terminal 82a, and the cable is connected to the second RF generator 31b. In addition, the through-hole 80 is arranged so as to avoid the flow path 1110 a of the base 1110 . In the example of connection to the bias electrode 33 shown in FIG. 7, the base 1110 and the bias electrode 33 are electrically insulated by the ceramic member 1111a and the insulating sleeve 81 .

[Modification 2]
In the above-described embodiment and modification 1, the base 1110 and the bias electrode 33 are electrically insulated, but the base 1110 and the bias electrode 33 may be electrically connected. The embodiment will be described as Modified Example 2. FIG. Note that the plasma processing apparatus in Modification 2 is the same as that of the above-described embodiment, so redundant descriptions of the configuration and operation thereof will be omitted.

FIG. 8 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 2. In FIG. In FIG. 8, the base 1110 is assumed to be a conductive member. As shown in FIG. 8, in the through hole 80 of the base 1110, a socket terminal 82 for power supply, a power supply line 83, and a joint terminal 84 are provided. The socket terminal 82, the feeder line 83 and the joint terminal 84 are examples of the conductor 81a. The socket terminal 82 is fixed to the inner wall of the through hole 80 with a conductive adhesive 86 . As the adhesive 86, for example, an adhesive containing solder or a conductive paste can be used. Also, the upper portion of the socket terminal 82 and the joint terminal 84 are connected by a feeder line 83 . The junction terminal 84 is joined to the terminal 33 a of the bias electrode 33 . A cable (not shown) is connected to the socket terminal 82, and the cable is connected to the second RF generator 31b. In addition, the through-hole 80 is arranged so as to avoid the flow path 1110 a of the base 1110 . In the example of connection to the bias electrode 33 shown in FIG. 8, the base 1110 and the bias electrode 33 are electrically connected by the adhesive 86, the socket terminal 82, the feeder line 83 and the junction terminal 84. FIG. That is, in Modification 2, the base 1110 and the bias electrode 33 have the same potential. Therefore, it is possible to suppress electric discharge in the through holes 80 and heat transfer gas supply holes (not shown). In addition, since the diameter of the through-hole 80 can be reduced without using the insulating sleeve 81 and the adhesives 85 and 85a having different heat conduction characteristics, the change in the heat dissipation from the surroundings can be reduced, and the occurrence of hot spots on the substrate W can be suppressed. be able to. Furthermore, the step of providing the insulating sleeve 81 can be omitted.

[Modification 3]
In Modification 2 above, the power supply line 83 is used in the through hole 80 for connection to the bias electrode 33, but the socket terminal 82 may be joined to the terminal 33a of the bias electrode 33. The form will be described as Modified Example 3. Note that the plasma processing apparatus in Modification 3 is the same as that of the above-described embodiment, so redundant descriptions of the configuration and operation thereof will be omitted.

FIG. 9 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 3. In FIG. In FIG. 9, the base 1110 is assumed to be a conductive member. As shown in FIG. 9, in the through hole 80 of the base 1110, a socket terminal 82a for power supply is provided. The socket terminal 82a is an example of the conductor 81a. The socket terminal 82a is fixed to the inner wall of the through hole 80 with a conductive adhesive 86a. Also, the upper portion of the socket terminal 82 a is joined to the terminal 33 a of the bias electrode 33 . A cable (not shown) is connected to the lower portion of the socket terminal 82a, and the cable is connected to the second RF generator 31b. In addition, the through-hole 80 is arranged so as to avoid the flow path 1110 a of the base 1110 . In the example of connection to the bias electrode 33 shown in FIG. 9, the base 1110 and the bias electrode 33 are electrically connected by the adhesive 86a and the socket terminal 82a. That is, in Modification 3, the base 1110 and the bias electrode 33 have the same potential. Therefore, it is possible to suppress electric discharge in the through holes 80 and heat transfer gas supply holes (not shown). In addition, since the diameter of the through-hole 80 can be reduced without using the insulating sleeve 81 and the adhesives 85 and 85a having different heat conduction characteristics, the change in the heat dissipation from the surroundings can be reduced, and the occurrence of hot spots on the substrate W can be suppressed. be able to. Furthermore, the step of providing the insulating sleeve 81 can be omitted.

[Image of electric potential]
Here, the base 1110 and the bias electrode 33 shown in FIGS. 6 and 7 are electrically insulated, and the base 1110 and the bias electrode 33 shown in FIGS. 8 and 9 are electrically connected. An image of each potential in the case of and in the case of being connected will be described with reference to FIG. 10 . FIG. 10 is a diagram showing an example of an image of each potential on the base, the bias electrode, and the substrate. A graph 90 shown in FIG. 10 is an image of the potential of each part when the base 1110 and the bias electrode 33 are electrically insulated. As shown in graph 90 , when base 1110 and bias electrode 33 are electrically insulated, potential difference 91 is generated between base 1110 and bias electrode 33 . Further, a voltage phase difference 92 is generated between the base 1110 , the bias electrode 33 and the substrate W due to the impedance of each part of the substrate supporting part 11 . Due to the phase difference 92, large potential differences such as a potential difference 93 between the base 1110 and the bias electrode 33 and a potential difference 94 between the base 1110 and the substrate W temporarily occur.

A graph 95 shown in FIG. 10 is an image of the potential of each part when the base 1110 and the bias electrode 33 are electrically connected. As shown in the graph 95, when the base 1110 and the bias electrode 33 are electrically connected, there is no potential difference between the base 1110 and the bias electrode 33 and they have the same potential. Further, a voltage phase difference 96 is generated between the substrate W and the base 1110 and the bias electrode 33 due to the impedance of each part of the substrate supporting part 11 . A potential difference 97 between the substrate W and the base 1110 and the bias electrode 33 due to the phase difference 96 is smaller than the potential difference 94 shown in the graph 90 . As a result, electrical discharge in the heat transfer gas and dielectric breakdown between the power supply line and the base 1110 can be suppressed. Moreover, since the base 1110 and the bias electrode 33 are electrically connected, it is possible to suppress the potential difference when supplying the source RF signal to the base 1110 . Furthermore, since the impedance between the bias electrode 33 and the substrate W is reduced, the voltage phase difference can also be reduced.

[Modifications 4 to 6]
In Modifications 2 and 3, the socket terminals 82 and the like corresponding to the conductors 81a are provided in the through holes 80, but other connection methods may be used. ∼6. The plasma processing apparatuses in Modifications 4 to 6 are the same as those in the above-described embodiments, so redundant descriptions of their configurations and operations will be omitted.

FIG. 11 is a diagram showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 4. In FIG. In FIG. 11, the base 1110 is assumed to be a conductive member. As shown in FIG. 11, the base 1110 is provided with an upper hole 80a and a lower hole 80b having a smaller diameter than the hole 80a. The holes 80a and 80b are connected to form a through hole. The holes 80a and 80b may not be connected, and may be provided independently. The upper portion of the hole 80a is fixed with a conductive adhesive 87 so that the terminal 33a of the bias electrode 33 and the side surface of the hole 80a are electrically connected. As the adhesive 87, for example, solder, adhesive containing conductive paste, sintered silver, brazing material, or the like can be used. A cable (not shown) is connected to the hole 80b, and the cable is connected to the second RF generator 31b. An existing hole may be substituted for the hole 80b, and the position on the lower surface side of the base 1110 is not limited. The holes 80a and 80b are arranged so as to avoid the flow path 1110a of the base 1110. As shown in FIG. In the example of connection to the bias electrode 33 shown in FIG. 11 , the base 1110 and the bias electrode 33 are electrically connected by the adhesive 87 . That is, in Modification 4, the base 1110 and the bias electrode 33 have the same potential. Therefore, electric discharge in the holes 80a and 80b and heat transfer gas supply holes (not shown) can be suppressed. In addition, since the diameter of the hole 80a can be reduced without using the insulating sleeve 81 and the adhesives 85, 85a having different heat conduction characteristics, the change in heat dissipation from the surroundings can be reduced, and the occurrence of hot spots on the substrate W can be suppressed. can be done. Furthermore, the step of providing the insulating sleeve 81 can be omitted.

12A and 12B are diagrams showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 5. FIG. In FIG. 12, the base 1110 is assumed to be a conductive member. As shown in FIG. 12, the base 1110 is provided with a hole 80b on the bottom side. A leaf spring 87a for contacting the terminal 33a of the bias electrode 33 is provided on the upper surface side of the base 1110 corresponding to the hole 80b. Note that the hole 80b and the plate spring 87a do not have to be provided at corresponding positions. The leaf spring 87a is an electrical contact that connects the base 1110 and the terminal 33a. Note that the plate spring 87a may be in another form such as a coil spring as long as it functions as an electrical contact. A cable (not shown) is connected to the hole 80b, and the cable is connected to the second RF generator 31b. An existing hole may be substituted for the hole 80b, and the position on the lower surface side of the base 1110 is not limited. The hole 80b is arranged so as to avoid the flow path 1110a of the base 1110. As shown in FIG. In the example of connection to the bias electrode 33 shown in FIG. 12, the base 1110 and the bias electrode 33 are electrically connected by the leaf spring 87a. That is, in Modification 5, the base 1110 and the bias electrode 33 have the same potential. Therefore, it is possible to suppress electric discharge in the holes 80b and heat transfer gas supply holes (not shown). Moreover, since no hole is provided on the upper surface side of the base 1110, the occurrence of hot spots on the substrate W can be suppressed. Furthermore, the step of providing the insulating sleeve 81 can be omitted.

13A and 13B are diagrams showing an example of connection to the bias electrode when the base and the bias electrode are electrically connected in Modification 6. FIG. In FIG. 13, the base 1110 is assumed to be a conductive member. As shown in FIG. 13, the base 1110 is provided with an upper hole 80a, a lower hole 80b having a smaller diameter than the hole 80a, and a crimped portion 80c. The holes 80a and 80b are connected to form a through hole. A connection terminal 87b and a feeder line 87c are provided inside the holes 80a and 80b. The junction terminal 87 b is joined to the terminal 33 a of the bias electrode 33 . The power supply line 87c is electrically connected to the base 1110 by connecting the upper portion to the joint terminal 87b and crimping the lower portion to the crimping portion 80c. A cable (not shown) is connected to the crimped portion 80c, and the cable is connected to the second RF generator 31b. Existing holes and crimped portions may be substituted for the hole 80b and the crimped portion 80c, and the position on the lower surface side of the base 1110 is not limited. The holes 80a and 80b and the crimped portion 80c are arranged so as to avoid the flow path 1110a of the base 1110. As shown in FIG. In the example of connection to the bias electrode 33 shown in FIG. 13, the base 1110 and the bias electrode 33 are electrically connected by the crimped portion 80c, the feeder line 87c and the junction terminal 87b. That is, in Modification 6, the base 1110 and the bias electrode 33 have the same potential. Therefore, electric discharge in the holes 80a and 80b and heat transfer gas supply holes (not shown) can be suppressed. In addition, since the diameter of the hole 80a can be reduced without using the insulating sleeve 81 and the adhesives 85, 85a having different heat conduction characteristics, the change in heat dissipation from the surroundings can be reduced, and the occurrence of hot spots on the substrate W can be suppressed. can be done. Furthermore, the step of providing the insulating sleeve 81 can be omitted.

[Modification 7]
In the above embodiment and Modifications 1 to 6, a conductive member is used for the base 1110, but the base 1110 may be formed of a dielectric material. do. Since the plasma processing apparatus in Modification 7 is the same as that of the above-described embodiment, redundant description of the configuration and operation thereof will be omitted.

In Modified Example 7, the adhesive layer 1112 of the body portion 111 is made conductive, and only the periphery of the terminal 33a of the bias electrode 33 is surrounded by an insulator. A socket terminal similar to, for example, the socket terminal 82a of Modification 3 is joined to the terminal 33a, and a cable from the second RF generator 31b is electrically connected to the socket terminal. In this case, the adhesive layer 1112 and the bias electrode 33 are electrically insulated. In Modification 7, for example, a socket terminal similar to the socket terminal 82a of Modification 3 is joined to the adhesive layer 1112, and a cable from the second RF generation unit 31b is electrically connected to the socket terminal. be done. The adhesive layer 1112 and the bias electrode 33 are joined at the terminal 33a. In this case, the adhesive layer 1112 and the bias electrode 33 are electrically connected and have the same potential. Regardless of whether the adhesive layer 1112 and the bias electrode 33 are electrically insulated or connected, the efficiency of the bias power on the low frequency side can be improved as in the above embodiments. In addition, when the adhesive layer 1112 and the bias electrode 33 are electrically connected, it is possible to suppress electric discharge in the through hole 80 and the heat transfer gas supply hole (not shown).

(Second embodiment)
In the above-described first embodiment, a single-layer electrode is used as the bias electrode 33, but a bias electrode having a plurality of layers may be used. An embodiment will be described. The plasma processing apparatus according to the second embodiment is the same as the first embodiment described above except for the arrangement of various electrodes in the electrostatic chuck 1111, so redundant descriptions of the configuration and operation will be omitted.

FIG. 14 is a partial cross-sectional view showing an example of an electrostatic chuck according to the second embodiment. As shown in FIG. 14, in the second embodiment, a bias electrode 330 composed of a first layer 331, a second layer 332 and a third layer 333 is provided instead of the bias electrode 33 of the first embodiment. Further, in the second embodiment, the third layer 333 extends to the region 340 instead of the bias electrode 34 of the first embodiment. It should be noted that the bias electrode 330 may be further supplied with source power for plasma generation.

In the ceramic member 1111a, in the central region 111a, from the central region 111a side, the electrostatic electrode 1111b, the first layer 331, the second layer 332 and the third layer 333 of the bias electrode 330, and the electrostatic electrode 1111b It includes a supply layer 350 and a heater electrode 1111c. The electrostatic electrode 1111 b is connected to the supply layer 350 with a plurality of vias 351 . Supply layer 350 is connected to terminal 353 through via 352 .

The bias electrode 330 is connected between the first layer 331 and the second layer 332 by a plurality of vias 334 , and is connected between the second layer 332 and the third layer 333 by a plurality of vias 335 . Third layer 333 is connected to terminal 337 through via 336 . The terminal 337 corresponds to the terminal 33a of the first embodiment. The bias electrode 330 is an example of the second electrode, and the first layer 331 and the second layer 332 are examples of the first layer and the second layer. Either one of the second layer 332 and the third layer 333 may be omitted. For example, if the second layer 332 is omitted, the third layer 333 is an example of the second layer. Also, the first layer 331 functions as the bias electrode 330 in the central region 111a. In this case, the second layer 332 and the third layer 333 level the electric field distribution in the first layer 331 by supplying RF signals (RF power) supplied from the RF power supply 31 to the first layer 331 from a plurality of locations. function to That is, by providing the second layer 332 and the third layer 333, the in-plane uniformity of plasma processing can be improved. Heater electrode 1111 c is connected to terminal 356 through via 355 .

In the ceramic member 1111a, the annular region 111b is provided with a third bias electrode layer 333, a supply layer 350, and a heater electrode 357 in this order from the annular region 111b side. That is, as shown in FIG. 14, a dielectric ceramic member 1111a is arranged between the electrodes and between the layers in the electrostatic chuck 1111 in the second embodiment. Further, an edge ring 1120 and a cover ring 1121 are mounted as the ring assembly 112 on the annular region 111b. The edge ring 1120 is made of, for example, a conductive member (conductive material) such as silicon or silicon carbide, or a semiconductor. The cover ring 1121 is made of, for example, a dielectric (insulating material) such as quartz. That is, the annular region 111b, which is an example of the second support surface, supports the edge ring 1120 made of a conductive member and the cover ring 1121 made of a dielectric. A region 340 of the third layer 333, which is an example of the fourth electrode, is arranged in the electrostatic chuck 1111 corresponding to the edge ring 1120, and a region 341 corresponding to the cover ring 1121 is arranged in the electrostatic chuck 1111. Not placed.

In the annular region 111b, the region 340 of the third layer 333 functions as a bias electrode. That is, in the second embodiment, part of the bias electrode in the central region 111a and the bias electrode in the annular region 111b are integrated. In addition, in the annular region 111b, the supply layer 350 also has the effect of attracting the edge ring 1120 instead of the electrostatic electrode 1111d of the first embodiment. Heater electrode 357 is connected to terminal 359 through via 358 . Heater electrode 357 is an example of a temperature regulation module and is configured to regulate edge ring 1120 to a target temperature.

Next, with reference to FIGS. 15 to 19, respective cross sections of the electrostatic electrode 1111b, the first layer 331, the second layer 332, the third layer 333, and the supply layer 350 in plan view of the electrostatic chuck 1111 are described. explain. In FIGS. 15 to 19, hatching representing the cross section is omitted except for a part, in order to make the structure of the via and the like easier to see. FIG. 15 is a cross-sectional view showing an example of an electrostatic electrode in plan view. As shown in FIG. 15, the electrostatic electrode 1111b is formed in a disc shape corresponding to the central region 111a. The electrostatic electrode 1111b has a thickness of, for example, 10 μm to 20 μm. In the electrostatic electrode 1111b, for example, 16 vias 351 are arranged at equal intervals on the circumference 351a. Electrostatic electrode 1111b is electrically connected to supply layer 350 through each via 351 . Also, the distance from the upper surface of the central region 111a to the electrostatic electrode 1111b (thickness of the ceramic member 1111a) can be set to 0.35 mm, for example.

FIG. 16 is a cross-sectional view showing an example of the first layer of the bias electrode in plan view. As shown in FIG. 16, the first layer 331 is formed in a disk shape corresponding to the central region 111a. The first layer 331 has a thickness of, for example, 10 μm to 20 μm. The first layer 331 is not provided in each region 331a through which each via 351 penetrates so that each via 351 and the first layer 331 are not electrically connected. That is, in the region 331a, each via 351 and the first layer 331 are insulated by the ceramic member 1111a. Also, the distance from the electrostatic electrode 1111b to the first layer 331 (the thickness of the ceramic member 1111a) can be set to 0.35 mm, for example. That is, the distance from the upper surface of the central region 111a to the first layer 331 can be set to approximately 0.7 mm, for example. This distance is shorter than the distance (for example, about 5 mm) from the first layer 331 to the top surface of the base 1110 .

FIG. 17 is a cross-sectional view showing an example of the second layer of the bias electrode in plan view. As shown in FIG. 17, the second layer 332 is formed in a disk shape corresponding to the central region 111a. The second layer 332 has a thickness of, for example, 10 μm to 20 μm. The second layer 332 is not provided in each region 332a through which each via 351 penetrates so that each via 351 and the second layer 332 are not electrically connected. That is, in the region 332a, the via 351 and the second layer 332 are insulated by the ceramic member 1111a. In the second layer 332, vias 334, for example, 16 on each of concentric circles 334a to 334c and 8 on a circumference 334d, are arranged at equal intervals. 1 is placed in The second layer 332 is electrically connected to the first layer 331 through each via 334 .

FIG. 18 is a cross-sectional view showing an example of the third layer of the bias electrode in plan view. As shown in FIG. 18, the third layer 333 is formed in a disk shape corresponding to the central region 111a and the region of the annular region 111b where the edge ring 1120 is placed (corresponding to the region 340 in FIG. 14). It is Note that the third layer 333 is not formed in a region of the annular region 111b where the cover ring 1121 is placed (corresponding to region 341 in FIG. 14). Further, the third layer 333 is divided into an inner peripheral side and an outer peripheral side by a ring-shaped region 342 at substantially the center in the radial direction. In FIG. 18 , a portion corresponding to a region 341 on which the outermost cover ring 1121 is placed and a region 342 are hatched so as to be easily distinguished from the third layer 333 . The inner peripheral side and the outer peripheral side of the third layer 333 are electrically connected via each via 335 and the second layer 332 . The third layer 333 has a thickness of, for example, 10 μm to 20 μm. Each region 333a through which each via 351 penetrates is not provided with the third layer 333 so that each via 351 and the third layer 333 are not electrically connected. That is, in the region 333a, each via 351 and the third layer 333 are insulated by the ceramic member 1111a. In the third layer 333, vias 335, for example, 16 on each of the circumferences 335a to 335c and 8 on the circumference 335d, which are concentric circles, are arranged at regular intervals. 1 is placed in That is, each via 335 may be provided at the same position as each via 334 . Note that each via 335 may be located at a different position and in a different number from each via 334 . Also, in the third layer 333, vias 336 for electrically connecting to terminals 337 are arranged, for example, three on the inner peripheral side and three on the outer peripheral side. That is, a plurality of terminals 337 may be provided.

FIG. 19 is a cross-sectional view showing an example of a supply layer to an electrostatic electrode in plan view. As shown in FIG. 19, the supply layer 350 is formed in a ring shape from the vicinity of the boundary between the central region 111a and the annular region 111b to a portion of the annular region 111b where the edge ring 1120 is placed. there is The feed layer 350 has a thickness of, for example, 10 μm to 20 μm. In the feed layer 350, each via 351 is arranged on a circumference 351b. That is, the supply layer 350 is electrically connected to the electrostatic electrode 1111b through each via 351. FIG. In addition, the supply layer 350 is electrically connected to a terminal 353 via a via 352 provided in, for example, a protrusion 352a provided at one location on the outer peripheral side.

Next, the sheath potential near the boundary between the central region 111a and the annular region 111b will be described with reference to FIG. FIG. 20 is a diagram showing an example of the sheath potential near the ring assembly in the second embodiment. Note that in FIG. 20, a specific potential of the plasma sheath is represented as a sheath potential 343. As shown in FIG. As shown in FIG. 20, in the central region 111a, a bias RF signal is supplied from the terminal 337 to the first layer 331 through the via 336, the third layer 333, the via 335, the second layer 332, and the via 334. Acts as a bias electrode. In the region of the annular region 111b where the edge ring 1120 is placed, a bias RF signal is supplied from the terminal 337 through the via 336 to the third layer 333 including the region 340, and the region 340 acts as a bias electrode. At this time, since the impedance of the path from the first layer 331 through the substrate W and the impedance of the path from the region 340 through the edge ring 1120 are close to each other, the height of the sheath potential 343 is above the substrate W and at the edge. It is almost aligned with the ring 1120 . That is, since the region 340 of the third layer 333 exists in the region where the edge ring 1120 is placed in the annular region 111b, the sheath potential 343 on the edge ring 1120 is substantially the same as that on the substrate W. Therefore, in the electrostatic chuck 1111 of the second embodiment, the ions are vertically incident even at the edge of the substrate W, so that the tilting of the holes formed in the substrate W can be suppressed. On the other hand, the region of the annular region 111b on which the covering 1121 is placed is the region 341 where the third layer 333 does not exist, so the sheath potential 343 on the covering 1121 is lowered. As a result, damage and consumption of the cover ring 1121 can be suppressed. In addition, the existence of the region 340 can reduce the influence of the thickness of the edge ring 1120 on the sheath potential 343, so that the edge ring 1120 can be thickened and the life of the edge ring 1120 can be extended.

[Experimental result]
Next, experimental results in the second embodiment will be described with reference to FIG. FIG. 21 is a diagram showing an example of experimental results in the second embodiment. In FIG. 21, as graphs of the etching rate in the diameter direction of the substrate W, a graph 360 of an example using the electrostatic chuck 1111 of the second embodiment and a graph 361 of a reference example in which a bias RF signal is supplied to the base 1110h are shown. and The processing conditions for both the embodiment and the reference example are the pressure in the plasma processing chamber 10 of 20 mTorr (2.67 Pa), a 27 MHz source RF signal of 500 W, and a 400 kHz bias RF signal of 1600 W. The example etch rate was ±3.5%, as shown in graph 360 . Also, the potential (Vpp) of the substrate W in the example was 2424V. On the other hand, the etching rate of the reference example was ±2.5% as shown in graph 361 . Also, the potential (Vpp) of the substrate W of the reference example was 3337V. That is, in the example, the etching rate is improved by about 5% and the potential (Vpp) of the substrate W is lowered by about 28% as compared with the reference example.

Furthermore, comparing the graph 360 and the graph 361, in the regions 362 and 363 near the edge of the substrate W, the graph 360 rises smoothly, while the graph 361 falls like falling. In the example, the sheath potential did not drop at the edge of the substrate W and tilting did not occur. ting is considered to be occurring. Thus, in the second embodiment, since the distance between the first layer 331 and the region 340 of the third layer 333 functioning as bias electrodes and the substrate W and the edge ring 1120 is short, the impedance of each path is lowered. be able to. Therefore, since a large amount of current can flow as a bias RF signal, the voltage can be lowered, and abnormalities in various parts of the electrostatic chuck 1111 (for example, the rear surface of the mounted substrate W, lift pin holes, helium supply holes, etc.) can be detected. Discharge can be suppressed. Moreover, in the embodiment, when the bias RF signal having the same power as that of the reference example is supplied from the RF power supply 31, the etching rate can be improved more than the reference example. That is, in the second embodiment, it is possible to use up to a high power range without abnormal discharge, and it is possible to improve the etching rate by improving the RF efficiency.

As described above, according to each embodiment, the substrate support part 11 is the substrate support part 11 arranged in the processing container (plasma processing chamber 10), and the first support surface (central region 111a) for supporting the substrate W is provided. ), and a first electrode (electrostatic electrode 1111b) and a second electrode (bias electrodes 33, 330) are provided inside in order from the first support surface side, and the electrostatic chuck is formed of a dielectric material. 1111, and a base 1110 that supports the electrostatic chuck 1111. The second electrode is arranged at a position where the distance to the first support surface is equal to or less than the distance to the base. A voltage for attracting the substrate W is applied to the electrode, and bias power is supplied to the second electrode. As a result, the efficiency of the bias power on the low frequency side can be improved.

Also, according to each embodiment, the base 1110 is formed of a conductive member. As a result, the efficiency of the bias power on the low frequency side can be improved.

Also, according to each embodiment, the second electrode is arranged at a position where the distance to the first support surface is shorter than the distance to the base 1110 . As a result, the efficiency of the bias power on the low frequency side can be improved.

Further, according to each embodiment, the electrostatic chuck 1111 further includes a heater electrode 1111c inside, and the second electrode is arranged between the first electrode and the heater electrode 1111c. As a result, the heater electrode 1111c and the bias electrodes 33, 330 can be set at substantially the same potential.

Further, according to the first embodiment, the electrostatic chuck 1111 includes a second support surface (annular region 111b) that surrounds the first support surface and supports the edge ring (ring assembly 112). In addition, a third electrode (electrostatic electrode 1111d) and a fourth electrode (bias electrode 34) are provided inside in order from the second support surface side, and the fourth electrode is a distance from the second support surface. is arranged at a position below the distance to the base 1110, a voltage for attracting the edge ring is applied to the third electrode, and a bias power is supplied to the fourth electrode. As a result, even in the annular region 111b, the efficiency of the bias power on the low frequency side can be improved.

Also, according to the first embodiment, the third electrode is integrated with the first electrode. As a result, even in the annular region 111b, the efficiency of the bias power on the low frequency side can be improved.

Further, according to each embodiment, the electrostatic chuck 1111 includes a second support surface (annular region 111b) that surrounds the first support surface and supports the edge ring (ring assembly 112). , a fourth electrode (bias electrode 34, region 340) is provided inside the second support surface, and the fourth electrode is positioned at a distance to the second support surface that is less than or equal to the distance to the base 1110. bias power is supplied to the fourth electrode. As a result, even in the annular region 111b, the efficiency of the bias power on the low frequency side can be improved.

Also, according to each embodiment, the fourth electrode is arranged at a position where the distance to the second support surface is shorter than the distance to the base 1110 . As a result, even in the annular region 111b, the efficiency of the bias power on the low frequency side can be improved.

Also, according to each embodiment, the fourth electrode is integral with the second electrode. As a result, even in the annular region 111b, the efficiency of the bias power on the low frequency side can be improved.

Further, according to the seventh modification, the base 1110 is made of a dielectric material and has a conductive adhesive layer 1112 between itself and the electrostatic chuck 1111 . As a result, even if the base 1110 is a dielectric, the efficiency of the bias power on the low frequency side can be improved.

Further, according to each embodiment, the second electrode is further supplied with source power for plasma generation. As a result, even when the source power is supplied from the bottom of the substrate W, the efficiency of the bias power on the low frequency side can be improved.

Further, according to each of the embodiments and Modifications 1 and 7, the second electrode is not electrically connected to the base 1110 or the conductive adhesive layer 1112 . As a result, the efficiency of the bias power on the low frequency side can be improved.

Further, according to modifications 2 to 7, the second electrode is electrically connected to the base 1110 or the conductive adhesive layer 1112, and the bias power is supplied to the base 1110 or the conductive adhesive layer 1112. be done. As a result, discharge in various holes inside the base 1110 can be suppressed.

Further, according to each of the embodiments and Modifications 1 to 6, the second electrode is formed by using a conductive paste, sintered silver, brazing material, solder, a socket, a leaf spring, or crimping of a power supply line. It is electrically connected to the base 1110 or the conductive adhesive layer 1112 . As a result, the base 1110 or the conductive adhesive layer 1112 and the bias electrodes 33, 34, 330 can be at the same potential.

Also, according to each embodiment, the bias power is an AC or DC pulse. As a result, the efficiency of the bias power on the low frequency side can be improved.

Further, according to the second embodiment, the second electrode (bias electrode 330) includes a first layer (first layer 331) and a second layer (second layer 332). A dielectric is disposed between the layer and the second layer, and a plurality of vias 334 connect between the first layer and the second layer. As a result, abnormal discharge can be suppressed, and in-plane uniformity and etching rate can be improved.

Also according to the second embodiment, the second support surface supports an edge ring 1120 made of a conductive material or a semiconductor and a cover ring 1121 made of a dielectric. A fourth electrode is located within the electrostatic chuck 1111 corresponding to the edge ring 1120 and not located within the electrostatic chuck 1111 corresponding to the cover ring 1121 . As a result, the tilting of the hole formed at the edge of the substrate W can be suppressed. In addition, since the sheath potential 343 on the cover ring 1121 is lowered, damage and consumption of the cover ring 1121 can be suppressed.

Each embodiment disclosed this time should be considered as an illustration and not restrictive in all respects. Each of the embodiments described above may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Further, in each of the above-described embodiments, the case where the bias RF signal is supplied from the second RF generator 31b as the bias power has been described, but the present invention is not limited to this. For example, a bias DC signal may be supplied from the bias DC generator 32a as the bias power.

Further, in each of the above-described embodiments, the plasma processing apparatus 1 that performs processing such as etching on the substrate W using inductively coupled plasma as a plasma source has been described as an example, but the technology disclosed is not limited to this. . The plasma source is not limited to inductively coupled plasma, and any plasma source such as capacitively coupled plasma, microwave plasma, magnetron plasma, etc. can be used as long as it is an apparatus that processes a substrate W using plasma. .

Note that the present disclosure can also take the following configuration.
(1)
A substrate support disposed within the processing container,
an electrostatic chuck comprising a first supporting surface for supporting a substrate, internally provided with a first electrode and a second electrode in order from the first supporting surface side, and formed of a dielectric;
a base supporting the electrostatic chuck;
has
the second electrode is arranged at a position where the distance to the first support surface is equal to or less than the distance to the base;
A voltage for attracting the substrate is applied to the first electrode,
bias power is supplied to the second electrode;
substrate support.
(2)
The base is formed of a conductive member,
The substrate support portion according to (1) above.
(3)
The second electrode is arranged at a position where the distance to the first support surface is shorter than the distance to the base,
The substrate support part according to (1) or (2) above.
(4)
The electrostatic chuck further includes a heater electrode inside,
the second electrode is positioned between the first electrode and the heater electrode;
The substrate support portion according to any one of (1) to (3) above.
(5)
The electrostatic chuck is provided so as to surround the first support surface and includes a second support surface for supporting the edge ring, and a third electrode and a fourth electrode in order from the second support surface side. and electrodes are provided inside,
The fourth electrode is arranged at a position where the distance to the second support surface is equal to or less than the distance to the base,
A voltage is applied to the third electrode to attract the edge ring,
bias power is supplied to the fourth electrode;
The substrate supporting portion according to any one of (1) to (4) above.
(6)
wherein the third electrode is integral with the first electrode;
The substrate supporting portion according to (5) above.
(7)
The electrostatic chuck includes a second support surface that surrounds the first support surface and supports an edge ring, and a fourth electrode inside the second support surface,
The fourth electrode is arranged at a position where the distance to the second support surface is equal to or less than the distance to the base,
bias power is supplied to the fourth electrode;
The substrate supporting portion according to any one of (1) to (4) above.
(8)
The fourth electrode is arranged at a position where the distance to the second support surface is shorter than the distance to the base,
The substrate supporting portion according to any one of (5) to (7) above.
(9)
the fourth electrode is integral with the second electrode;
The substrate support portion according to any one of (5) to (8) above.
(10)
The base is made of a dielectric material and has a conductive adhesive layer between itself and the electrostatic chuck.
The substrate support portion according to (1) above.
(11)
The second electrode is further supplied with source power for plasma generation,
The substrate support portion according to any one of (1) to (10) above.
(12)
wherein the second electrode is not electrically connected to the base or the conductive adhesive layer;
The substrate supporting portion according to any one of (1) to (11) above.
(13)
the second electrode is electrically connected to the base or the conductive adhesive layer;
the bias power is supplied to the base or the conductive adhesive layer;
The substrate supporting portion according to any one of (1) to (11) above.
(14)
The second electrode is electrically connected to the base or the conductive adhesive layer using conductive paste, sintered silver, brazing material, solder, socket, leaf spring, or crimping of a power supply line. to be
The substrate support portion according to (13) above.
(15)
wherein the bias power is an AC or DC pulse;
The substrate support portion according to any one of (1) to (14) above.
(16)
The second electrode comprises a first layer and a second layer, the dielectric disposed between the first layer and the second layer, the first layer and the second layer are connected by a plurality of vias,
The substrate supporting portion according to any one of (1) to (15) above.
(17)
the second support surface supports the edge ring formed of a conductive material or semiconductor and the cover ring formed of a dielectric;
the fourth electrode is positioned within the electrostatic chuck corresponding to the edge ring and not positioned within the electrostatic chuck corresponding to the cover ring;
The substrate support portion according to any one of (5) to (9) above.
(18)
a processing vessel;
a substrate support disposed within the processing vessel;
The substrate supporting portion is
an electrostatic chuck comprising a first supporting surface for supporting a substrate, internally provided with a first electrode and a second electrode in order from the first supporting surface side, and formed of a dielectric;
a base supporting the electrostatic chuck;
has
The second electrode is arranged at a position where the distance to the first support surface is equal to or less than the distance to the base,
A voltage for attracting the substrate is applied to the first electrode,
bias power is supplied to the second electrode;
Plasma processing equipment.

Reference Signs List 1 plasma processing apparatus 10 plasma processing chamber 11 substrate supporting portion 31a first RF generating portion 31b second RF generating portion 33, 34, 330 bias electrode 33a, 337 terminal 80 through hole 80a, 80b hole 80c caulking portion 82, 82a Socket terminals 83, 87c Feed lines 84, 87b Joint terminals 86, 86a, 87 Adhesive 87a Leaf spring 111 Main body 111a Central region 111b Annular region 112 Ring assembly 331 First layer 332 Second layer 333 Third layer 334-336 Via 350 supply layer 1110 base 1111 electrostatic chuck 1111a ceramic member 1111b, 1111d electrostatic electrode 1111c heater electrode 1112 adhesion layer 1120 edge ring 1121 cover ring W substrate

Claims (18)

A substrate support disposed within the processing container,
an electrostatic chuck comprising a first supporting surface for supporting a substrate, internally provided with a first electrode and a second electrode in order from the first supporting surface side, and formed of a dielectric;
a base supporting the electrostatic chuck;
has
the second electrode is arranged at a position where the distance to the first support surface is equal to or less than the distance to the base;
A voltage for attracting the substrate is applied to the first electrode,
bias power is supplied to the second electrode;
substrate support. The base is formed of a conductive member,
The substrate support according to claim 1. The second electrode is arranged at a position where the distance to the first support surface is shorter than the distance to the base,
The substrate support part according to claim 1 or 2. The electrostatic chuck further includes a heater electrode inside,
the second electrode is positioned between the first electrode and the heater electrode;
The substrate support part according to claim 1 or 2. The electrostatic chuck is provided so as to surround the first support surface and includes a second support surface for supporting the edge ring, and a third electrode and a fourth electrode in order from the second support surface side. and electrodes are provided inside,
The fourth electrode is arranged at a position where the distance to the second support surface is equal to or less than the distance to the base,
A voltage is applied to the third electrode to attract the edge ring,
bias power is supplied to the fourth electrode;
The substrate support part according to claim 1 or 2. wherein the third electrode is integral with the first electrode;
A substrate support according to claim 5. The electrostatic chuck includes a second support surface that surrounds the first support surface and supports an edge ring, and a fourth electrode inside the second support surface,
The fourth electrode is arranged at a position where the distance to the second support surface is equal to or less than the distance to the base,
bias power is supplied to the fourth electrode;
The substrate support part according to claim 1 or 2. The fourth electrode is arranged at a position where the distance to the second support surface is shorter than the distance to the base,
A substrate support according to claim 5. the fourth electrode is integral with the second electrode;
A substrate support according to claim 5. The base is made of a dielectric material and has a conductive adhesive layer between itself and the electrostatic chuck.
The substrate support according to claim 1. The second electrode is further supplied with source power for plasma generation,
A substrate support according to claim 1 or 10. wherein the second electrode is not electrically connected to the base or the conductive adhesive layer;
A substrate support according to claim 10. the second electrode is electrically connected to the base or the conductive adhesive layer;
the bias power is supplied to the base or the conductive adhesive layer;
A substrate support according to claim 10. The second electrode is electrically connected to the base or the conductive adhesive layer using conductive paste, sintered silver, brazing material, solder, socket, leaf spring, or crimping of a power supply line. to be
14. A substrate support according to claim 13. wherein the bias power is an AC or DC pulse;
The substrate support part according to claim 1 or 2. The second electrode comprises a first layer and a second layer, the dielectric disposed between the first layer and the second layer, the first layer and the second layer are connected by a plurality of vias,
The substrate support part according to claim 1 or 2. the second support surface supports the edge ring formed of a conductive material or semiconductor and the cover ring formed of a dielectric;
the fourth electrode is positioned within the electrostatic chuck corresponding to the edge ring and not positioned within the electrostatic chuck corresponding to the cover ring;
A substrate support according to claim 7. a processing vessel;
a substrate support disposed within the processing vessel;
The substrate support part
an electrostatic chuck comprising a first supporting surface for supporting a substrate, internally provided with a first electrode and a second electrode in order from the first supporting surface side, and formed of a dielectric;
a base supporting the electrostatic chuck;
has
the second electrode is arranged at a position where the distance to the first support surface is equal to or less than the distance to the base;
A voltage for attracting the substrate is applied to the first electrode,
bias power is supplied to the second electrode;
Plasma processing equipment.

Images