Electrostatic chuck

Abstract

Provided is a technique capable of improving temperature uniformity of a substrate held by an electrostatic chuck. The electrostatic chuck includes: a dielectric member on which the substrate is placed; and an electrostatic electrode disposed within the dielectric member. The dielectric member includes: a first upper surface having a gas outflow portion from which gas flows out; and a ring-shaped sealing tape disposed on the outside of the first upper surface and having a height higher than that of the first upper surface. The sealing tape includes: an outer peripheral portion; and an inner peripheral portion having a lower height than the outer peripheral portion. The electrostatic electrode is disposed at least directly below the inner peripheral portion of the sealing tape.

Description

Technical Field

[0001] An exemplary embodiment of the present invention relates to an electrostatic chuck. Background Art

[0002] As a technique for providing an electrostatic chuck having an annular seal belt for supporting the outer periphery of a substrate, there is a technique described in Patent Document 1.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent document 1: Japanese Patent Application Publication No. 2021-15820. Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present invention provides a technology capable of improving the temperature uniformity of a substrate held by an electrostatic chuck.

[0008] Technical solutions to the problem

[0009] An electrostatic chuck according to an exemplary embodiment of the present invention includes: a dielectric component for mounting a substrate; and an electrostatic electrode arranged in the dielectric component, the dielectric component including: a first upper surface having a gas outflow portion for gas outflow; and an annular sealing belt arranged outside the first upper surface and having a height higher than the first upper surface, the sealing belt including: an outer peripheral portion; and an inner peripheral portion having a height lower than the outer peripheral portion, and the electrostatic electrode is arranged at least directly below the inner peripheral portion of the sealing belt.

[0010] Effects of the Invention

[0011] According to an exemplary embodiment of the present invention, a technology capable of improving the temperature uniformity of a substrate held by an electrostatic chuck can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram for explaining a configuration example of a plasma processing system.

[0013] Figure 2 It is a diagram for explaining a configuration example of a capacitive coupling type plasma processing apparatus.

[0014] Figure 3 FIG. 1 is a diagram showing a configuration example of an electrostatic chuck in the embodiment of this example.

[0015] Figure 4 This is a diagram showing an example of the structure of ceramics when viewed from above.

[0016] Figure 5This is a diagram showing a structural example of the sealing tape in which the peripheral portion of the sealing tape is enlarged.

[0017] Figure 6 It is a figure which shows the structure of the sealing tape as a comparative example.

[0018] Figure 7 It is a figure which shows the structure of the sealing tape as a comparative example.

[0019] Figure 8 This is a table showing the relationship between the deflection amount of the substrate and the distance A.

[0020] Fig. 9 It is a diagram showing a structural example of a sealing tape having a third upper surface and an inclined surface in the inner peripheral portion.

[0021] Fig.10 It is a diagram showing a structural example of a sealing tape having a third upper surface and an inclined surface in the inner peripheral portion.

[0022] Fig.11 This is a diagram showing a structural example of a sealing tape in which the entire upper surface of the inner peripheral portion is an inclined surface.

[0023] Fig.12 This is a diagram showing a structural example of a sealing tape having an inclined upper surface and a vertical surface on the inner circumference.

[0024] Fig.13 This is a diagram showing a structural example of a sealing tape having an inclined upper surface and a vertical surface on the inner circumference. DETAILED DESCRIPTION

[0025] Hereinafter, each embodiment of the present invention will be described.

[0026] In an exemplary embodiment, an electrostatic chuck for holding a substrate is provided, the electrostatic chuck comprising: a dielectric component for mounting the substrate; and an electrostatic electrode arranged in the dielectric component, the dielectric component comprising: a first upper surface having a gas outflow portion for gas outflow; and an annular sealing belt arranged on the outer side of the first upper surface and having a height higher than the first upper surface, the sealing belt comprising: an outer peripheral portion; and an inner peripheral portion having a height lower than the outer peripheral portion, the electrostatic electrode being arranged at least directly below the inner peripheral portion of the sealing belt.

[0027] In an exemplary embodiment, the outer peripheral portion of the sealing band has a flat second upper surface, and the inner peripheral portion of the sealing band has a flat third upper surface.

[0028] In an exemplary embodiment, the upper surface of the inner peripheral portion of the sealing tape further has an inclined surface.

[0029] In an exemplary embodiment, the third upper surface is lower than the second upper surface and higher than the first upper surface.

[0030] In an exemplary embodiment, the third upper surface is lower than the second upper surface by at least 0.1 μm.

[0031] In an exemplary embodiment, the third upper surface is higher than the first upper surface by 3 μm or more.

[0032] In an exemplary embodiment, a distance from the third upper surface to the electrostatic electrode is in a range of 100 μm to 750 μm.

[0033] In an exemplary embodiment, the upper surface of the inner peripheral portion of the sealing tape includes only the third upper surface.

[0034] In an exemplary embodiment, the dielectric member further includes a plurality of protrusions that are arranged on the first upper surface and protrude upward relative to the first upper surface.

[0035] In an exemplary embodiment, the protrusion has a height that is the same as or lower than the outer peripheral portion of the sealing band.

[0036] In an exemplary embodiment, the protrusions have a height in a range of 5 μm to 50 μm.

[0037] In an exemplary embodiment, the inner end portion of the inner peripheral portion of the sealing band is located between the outer end portion of the outermost convex portion and the inner end portion of the outer peripheral portion of the sealing band.

[0038] In an exemplary embodiment, the inner end of the inner peripheral portion of the sealing band is located inward of a radially intermediate point between the outer end of the outermost convex portion and the inner end of the outer peripheral portion of the sealing band.

[0039] In an exemplary embodiment, the inner peripheral portion of the sealing band has a height equal to or greater than half the height of the protrusion.

[0040] In an exemplary embodiment, the electrostatic electrode is arranged from directly below the first upper surface to directly below the sealing band, and the outer end of the electrostatic electrode is located outside the radial center of the inner circumference of the sealing band.

[0041] In an exemplary embodiment, the outer end portion of the electrostatic electrode is located directly below the outer peripheral portion of the sealing band.

[0042] In an exemplary embodiment, the outer peripheral portion of the sealing band has a radial width in a range of 0.3 mm to 4 mm.

[0043] In an exemplary embodiment, the inner peripheral portion of the sealing band has a radial width in a range of 1 mm to 36 mm.

[0044] In an exemplary embodiment, the radial width of the inner peripheral portion of the sealing band is greater than the radial width of the outer peripheral portion of the sealing band.

[0045] In an exemplary embodiment, the upper surface of the inner peripheral portion of the sealing tape is entirely an inclined surface.

[0046] In an exemplary embodiment, the inner peripheral portion of the sealing band has an inclined upper surface and a vertical surface connected to each other in the radial direction.

[0047] In an exemplary embodiment, the dielectric member has a thickness in the vertical direction in a range of 0.5 mm to 5 mm.

[0048] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same or similar elements in the various figures, and repeated descriptions are omitted. Unless otherwise specified, the positional relationships of up, down, left, right, etc. are described based on the positional relationships shown in the accompanying drawings. The dimensional ratios in the accompanying drawings do not represent the actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0049] <An example of a plasma processing device>

[0050] Figure 1 : is a diagram for illustrating a structural example of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support portion 11, and a plasma generating portion 12. The plasma processing chamber 10 has a plasma processing space. In addition, the plasma processing chamber 10 has: at least one gas supply port for supplying at least one processing gas to the plasma processing space; and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to the gas supply portion 20 described later, and the gas exhaust port is connected to the exhaust system 40 described later. The substrate support portion 11 is arranged in the plasma processing space and has a substrate supporting surface for supporting a substrate.

[0051] The plasma generating unit 12 is capable of generating plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP: Capacitively Coupled Plasma), an inductively coupled plasma (ICP: Inductively Coupled Plasma), an ECR plasma (Electron-Cyclotron-resonance plasma: Electron cyclotron resonance plasma), a helicon wave excited plasma (HWP: Helicon Wave Plasma) or a surface wave plasma (SWP: Surface Wave Plasma), etc. In addition, various types of plasma generating units including an AC (Alternating Current: Alternating Current) plasma generating unit and a DC (Direct Current: Direct Current) plasma generating unit may be used. In one embodiment, the AC signal (AC electric power) used in the AC plasma generating unit has a frequency in the range of 100kHz to 10GHz. Therefore, the AC signal includes an RF (Radio Frequency: High Frequency) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100kHz to 150MHz.

[0052] The control unit 2 is capable of processing computer-executable commands, which are used to cause the plasma processing device 1 to perform various processes described in the present invention. The control unit 2 is capable of controlling the various elements of the plasma processing device 1 to perform the various processes described herein. In one embodiment, a part or all of the control unit 2 may be included in the plasma processing device 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 is capable of reading a program from the storage unit 2a2 and performing various control actions by executing the read program. The program may be pre-stored in the storage unit 2a2 or acquired via a medium when necessary. The acquired program is stored in the storage unit 2a2 and is read and executed from the storage unit 2a2 by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or a communication line connected to the communication interface 2a3. The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an 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).

[0053] Next, a configuration example of a capacitive coupling type plasma processing apparatus will be described as an example of the plasma processing apparatus 1 . Figure 2 It is a diagram for explaining a configuration example of a capacitive coupling type plasma processing apparatus.

[0054] A 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. In addition, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is capable of introducing 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 disposed in the plasma processing chamber 10. The shower head 13 is disposed 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 wall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the shell of the plasma processing chamber 10.

[0055] The substrate support portion 11 includes a main body 111 and a ring assembly 112. The main body 111 has: a central area 111a for supporting a substrate W; and an annular area 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular area 111b of the main body 111 surrounds the central area 111a of the main body 111 when viewed from above. The substrate W is arranged on the central area 111a of the main body 111, and the ring assembly 112 is arranged on the annular area 111b of the main body 111 in a manner surrounding the substrate W on the central area 111a of the main body 111. Therefore, the central area 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular area 111b is also referred to as a ring support surface for supporting the ring assembly 112.

[0056] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive component. The conductive component of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is arranged on the base 1110. The electrostatic chuck 1111 includes a ceramic component 1111a and an electrostatic electrode 1111b arranged in the ceramic component 1111a. The ceramic component 1111a is an example of a dielectric component. The ceramic component 1111a has a central area 111a. In one embodiment, the ceramic component 1111a also has an annular area 111b. In addition, other components surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating component, may have an annular area 111b. In this case, the ring assembly 112 may be arranged on the annular electrostatic chuck or the annular insulating component, or on both the electrostatic chuck 1111 and the annular insulating component. In addition, an RF or DC electrode can be configured in the ceramic component 1111a, in which case the RF or DC electrode can function as a lower electrode. When the bias RF signal or DC signal described later is connected to the RF / DC electrode, the RF or DC electrode is also referred to as a bias electrode. In addition, the conductive component of the base 1110 and the RF or DC electrode can function as two lower electrodes.

[0057] The ring assembly 112 includes one or more ring-shaped components. In one embodiment, the one or more ring-shaped components 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.

[0058] In addition, the substrate support portion 11 may include a temperature adjustment module for adjusting at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A flow path 1110a may be formed in the substrate support portion 11, and a heat transfer fluid such as salt water or gas flows in the flow path 1110a. The flow path 1110a may also be provided in the electrostatic chuck 1111 or the base 1110. The flow path 1110a may be connected to a refrigerant supply device 1110b. The refrigerant whose temperature is set by the refrigerant supply device 1110b may flow in the flow path 1110a and circulate, thereby cooling the electrostatic chuck 1111 and the substrate W held on the electrostatic chuck 1111. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are arranged in the ceramic component 1111a of the electrostatic chuck 1111. Furthermore, the substrate support portion 11 may include a heat transfer gas supply portion for supplying a heat transfer gas to a gap between the back surface of the substrate W and the central region 111 a .

[0059] The shower head 13 can introduce at least one processing gas from the gas supply part 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 processing gas supplied to the gas supply port 13a can be introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c through the gas diffusion chamber 13b. In addition, the shower head 13 includes an upper electrode. In addition, the gas introduction part may include, in addition to the shower head 13, one or more side gas injection parts (SGI: Side Gas Injector) installed in one or more openings formed on the side wall 10a.

[0060] 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 capable of supplying at least one process gas from the gas source 21 corresponding to each other to the shower head 13 via the flow controller 22 corresponding to each other. 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 at least one flow modulation device for modulating or pulsing the flow of at least one process gas.

[0061] 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 can supply at least one RF signal (RF power) such as a source RF signal and a bias RF signal to at least one lower electrode and / or at least one upper electrode. Thus, plasma can be formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generating unit 12. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential can be generated on the substrate W, and ion components in the formed plasma can be introduced into the substrate W.

[0062] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit, and can generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a can generate a plurality of source RF signals with different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0063] The second RF generating unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit, and is capable of generating 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 that of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100kHz to 60MHz. In one embodiment, the second RF generating unit 31b may be capable of generating a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In addition, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0064] In addition, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generating unit 32a and a second DC generating unit 32b. In one embodiment, the first DC generating unit 32a is connected to at least one lower electrode and is capable of generating a first DC signal. The generated first DC signal is applied to at least one lower electrode. In one embodiment, the second DC generating unit 32b is connected to at least one upper electrode and is capable of generating a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0065] In various embodiments, the first DC signal and the second DC signal may be pulsed. In this case, a sequence of voltage pulses based on DC is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulse may have a pulse waveform in the shape of a rectangle, a trapezoid, a triangle, or a combination thereof. In one embodiment, a waveform generator for generating a sequence of voltage pulses from a DC signal is connected between the first DC generator 32a and at least one lower electrode. Therefore, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. In the case where the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulse may have a positive polarity or a negative polarity. In addition, the sequence of voltage pulses may include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses in one cycle. In addition, the first DC generator 32a and the second DC generator 32b may be provided in addition to the RF power supply 31, or the first DC generator 32a may be provided instead of the second RF generator 31b.

[0066] The exhaust system 40 can be connected to the gas exhaust port 10e provided at the bottom of the plasma processing chamber 10, for example. The exhaust system 40 can include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s can be adjusted by the pressure regulating valve. The vacuum pump can include a turbomolecular pump, a dry pump, or a combination thereof.

[0067] <Example of the structure of an electrostatic chuck>

[0068] Figure 3 1 is a diagram showing a configuration example of an electrostatic chuck 1111 according to the embodiment of this example. In one embodiment, the electrostatic chuck 1111 includes a ceramic member 1111a as a dielectric member and an electrostatic electrode 1111b.

[0069] In one embodiment, the ceramic component 1111a has a first upper surface 200 and a sealing band 201 as an annular convex portion arranged outside the first upper surface 200. The sealing band 201 has a height higher than the first upper surface 200. The sealing band 201 may be formed integrally with other parts including the first upper surface 200 in the ceramic component 1111a, or may be formed separately.

[0070] Figure 41 is a diagram showing a structural example of the ceramic component 1111a when viewed from above. In one embodiment, the first upper surface 200 has a circular shape with the center of the ceramic component 1111a as the center. The sealing tape 201 has a ring shape with the center of the ceramic component 1111a as the center. By providing such a ring-shaped sealing tape 201, the electrostatically adsorbed substrate W contacts the upper surface of the sealing tape 201, preventing the heat transfer gas from leaking from the back of the substrate W and the space between the electrostatic chuck 1111 to the plasma processing space 10s.

[0071] In one embodiment, if Figure 3 As shown, the first upper surface 200 has a gas outflow portion 210, from which the heat transfer gas flows out. In one embodiment, the gas outflow portion 210 is connected to the heat transfer gas supply portion 212 through a gas flow path 211. The gas flow path 211 can pass through the inside of the substrate support portion 11. The heat transfer gas supply portion 212 can be arranged outside the chamber 10. One or more gas outflow portions 210 can be configured. The heat transfer gas can be a gas containing helium.

[0072] In one embodiment, a plurality of columnar protrusions 220 are disposed on the first upper surface 200. In one embodiment, the protrusions 220 protrude upward relative to the first upper surface 200. In one embodiment, the protrusions 220 have a cylindrical shape. Figure 4 As shown, the plurality of protrusions 220 may be arranged at equal intervals along the circumferential direction around the center of the first upper surface 200. The plurality of protrusions 220 may be arranged concentrically or radially with respect to the center of the first upper surface 200.

[0073] In one embodiment, if Figure 3 As shown, the sealing band 201 includes an annular outer peripheral portion 240 and an annular inner peripheral portion 241 having a lower height than the outer peripheral portion 240. The outer peripheral portion 240 is located outside the inner peripheral portion 241 in the radial direction X. Figure 5 1 is a diagram showing a structural example of the sealing tape 201 in which the peripheral portion of the sealing tape 201 is enlarged.

[0074] In one embodiment, the outer peripheral portion 240 has a flat second upper surface 250. In one embodiment, the outer peripheral portion 240 has a chamfered portion 251 at the outermost periphery of the upper surface.

[0075] In one embodiment, the inner peripheral portion 241 has only the flat third upper surface 260. That is, no protrusions or recesses are provided on the upper surface of the inner peripheral portion 241. However, as described later, a protrusion may be provided on the upper surface of the inner peripheral portion 241.

[0076] The third upper surface 260 may be lower than the second upper surface 250 and higher than the first upper surface 200. That is, the first upper surface 200, the third upper surface 260, and the second upper surface 250 may be formed in a stepped shape that becomes higher in sequence as they go outward in the radial direction X. In order to ensure a gap for the heat transfer gas to enter the space between the substrate W and the inner peripheral portion 241, the second upper surface 250 is configured so that the substrate W does not contact the second upper surface 250 even if the substrate W is warped. Therefore, it is preferred that the third upper surface 260 is lower than the second upper surface 250 by more than 0.1 μm.

[0077] The third upper surface 260 is higher than the first upper surface 200. As a result, the distance between the substrate W and the third upper surface 260 becomes closer, and the electrostatic attraction to the substrate W can be increased in the inner circumference 241. As a result, the electrostatic attraction of the sealing tape 201 to the substrate W can be ensured. Preferably, the third upper surface 260 is higher than the first upper surface 200 by more than 3 μm. In addition, the height difference ΔH between the third upper surface 260 and the second upper surface 250 (or the upper surface of the protrusion 220) is preferably within 7 μm. The third upper surface 260 can be based on the first upper surface 200 and have a height H2 that is more than half of the height H1 of the protrusion 220. In addition, the distance L1 from the third upper surface 260 to the electrostatic electrode 1111b in the up and down direction can be in the range of 100 μm to 750 μm.

[0078] A columnar or annular protrusion may also be provided on the third upper surface 260. By providing a protrusion that is closer to the substrate W than the third upper surface 260, the electrostatic attraction to the substrate W can be further increased in the inner peripheral portion 241. However, when a protrusion is provided on the third upper surface 260, there is a problem that the contact pressure between the substrate W and the peripheral portion 240 is weakened due to the contact between the upper surface of the protrusion and the substrate W, and the heat transfer gas leaks. Therefore, it is preferred that no protrusion is provided on the third upper surface 260, or even if a protrusion is provided, the upper surface of the protrusion is lower than the second upper surface 250. In addition, from the viewpoint of making the electrostatic attraction greater, it is preferred that the protrusion is formed in an annular shape. However, when the protrusion is formed in an annular shape, there is a problem that the space between the protrusion and the peripheral portion 240 is blocked due to the deflection of the substrate, and the heat transfer gas cannot enter the space. Therefore, it is preferably formed in a columnar shape when a protrusion is formed.

[0079] The inner peripheral portion 241 is provided between the outermost convex portion 220 and the outer peripheral portion 240. That is, the inner end portion 241a of the inner peripheral portion 241 is located between the outer end portion 220a of the outermost convex portion 220 and the inner end portion 240a of the outer peripheral portion 240. In addition, in order to ensure sufficient electrostatic attraction, the area of ​​the inner peripheral portion 241 is as large as possible. Therefore, it is preferred that the inner end portion 241a of the inner peripheral portion 241 is located inside the radial direction X intermediate point P1 between the outer end portion 220a of the outermost convex portion 220 and the inner end portion 240a of the outer peripheral portion 240. The inner peripheral portion 241 may be formed to the outer end portion 220a of the outermost convex portion 220. In addition, it is preferred that the radial direction X width D2 of the inner peripheral portion 241 is greater than the radial direction X width D1 of the outer peripheral portion 240.

[0080] However, if the area of ​​the inner peripheral portion 241 is too large, the substrate W may come into contact with the third upper surface 260 due to deflection of the substrate W. Figure 8 is the distance A between the outermost convex portion 220 and the inner end portion 240a of the outer peripheral portion 240 ( Figure 5 The inner circumference 241 can extend inward to the position of the outermost convex portion 220, but when the width D2 of the radial direction X of the inner circumference 241 is within 36 mm, the deflection of the substrate W is approximately within 7 μm. Therefore, it is preferred that the width D2 of the radial direction X of the inner circumference 241 is within the range of 1 mm to 36 mm.

[0081] The convex portion 220 may have a height H1 that is the same as or lower than the peripheral portion 240. The height H1 of the convex portion 220 may be in the range of 5 μm to 50 μm.

[0082] The width D1 of the outer peripheral portion 240 in the radial direction X may be in the range of 0.3 mm to 4 mm.

[0083] like Figure 3 As shown, the electrostatic electrode 1111b is in the ceramic component 1111a and can be arranged directly below the first upper surface 200 and the sealing tape 201. In one embodiment, the electrostatic electrode 1111b has a circular shape. In one embodiment, the electrostatic electrode 1111b is connected to a direct current (DC) power supply 301 via a switch 300. When a DC voltage from the DC power supply 301 is applied to the electrostatic electrode 1111b, an electrostatic attraction (Coulomb force) is generated between the ceramic component 1111a and the substrate W. The substrate W is attracted to the ceramic component 1111a by the electrostatic attraction and is adsorbed and held on the upper surface of the ceramic component 1111a.

[0084] In one embodiment, if Figure 5As shown in FIG. 1 , the electrostatic electrode 1111b is arranged from directly below the first upper surface 200 to directly below the sealing tape 201. The electrostatic electrode 1111b can be arranged at least directly below the inner peripheral portion 241. The outer end portion 1111b-1 of the electrostatic electrode 1111b can be located outside the position P2 of the center of the radial direction X of the inner peripheral portion 241. The outer end portion 1111b-1 can be located directly below the outer peripheral portion 240.

[0085] like Figure 3 As shown, the thickness L2 of the ceramic component 1111a in the vertical direction may be in the range of 0.5 mm to 5 mm.

[0086] <An example of plasma treatment method>

[0087] The plasma processing method includes an etching process for etching a film on the substrate W using plasma. In one embodiment, the plasma processing method is executed by the control unit 2 in the plasma processing apparatus 1 .

[0088] First, if Figure 2 As shown in FIG. 1 , the substrate W is introduced into the chamber 10 and placed on the substrate support 11. Figure 3 As shown in FIG. 1 , the substrate W is held by the electrostatic chuck 1111. At this time, the substrate W is placed on the ceramic component 1111a and contacts the outer periphery 240 of the sealing tape 201. A DC voltage is applied to the electrostatic electrode 1111b to generate an electrostatic attraction between the sealing tape 201 and the substrate W, so that the substrate W is attracted to the sealing tape 201.

[0089] exist Figure 2 In the substrate support portion 11 shown, a refrigerant is supplied from a refrigerant supply device 1110b to a flow path 1110a, and the electrostatic chuck 1111 and the substrate W held on the electrostatic chuck 1111 are temperature-controlled to a predetermined temperature.

[0090] Heat transfer gas is supplied from the heat transfer gas supply unit 212 to the gas outflow unit 210, and heat transfer gas is supplied from the gas outflow unit 210 to the space formed between the substrate W and the first upper surface 200. Heat transfer gas is also supplied to the space formed between the substrate W and the third upper surface 260. The sealing tape 201 seals the space between the first upper surface 200 and the substrate W in such a manner that the heat transfer gas does not leak into the plasma processing space 10s. The heat transfer gas adjusts the temperature of the substrate W from the inner side thereof.

[0091] Next, the process gas is Figure 2 The gas supply unit 20 shown in the figure supplies gas to the shower head 13, and supplies gas to the plasma processing space 10s from the shower head 13. The processing gas supplied at this time contains a gas for generating active species required for etching the substrate W.

[0092] One or more RF signals are supplied to the upper electrode and / or the lower electrode from the RF power supply 31. The atmosphere gas in the plasma processing space 10s may be exhausted from the gas exhaust port 10e, and the interior of the plasma processing space 10s may be depressurized. As a result, plasma is generated on the substrate support portion 11 in the plasma processing space 10s, and the substrate W is etched. Figure 3 The heat transfer gas supplied to the back side of the substrate W by the gas outflow portion 210 and the outer peripheral portion 240 of the sealing belt 201 after the temperature of the sealing belt 201 is adjusted by the refrigerant cools the substrate W.

[0093] In the embodiment of this example, the ceramic part 1111a of the electrostatic chuck 1111 has a first upper surface 200 and an annular sealing belt 201, the sealing belt 201 includes an outer peripheral portion 240 and an inner peripheral portion 241 having a height lower than the outer peripheral portion 240, and the electrostatic electrode 1111b is at least arranged directly below the inner peripheral portion 241. As a result, a gap can be generated between the inner peripheral portion 241 of the sealing belt 201 and the substrate W, and the heat transfer gas reaches the gap on the inner peripheral portion 241, and the temperature adjustment of the substrate W using the heat transfer gas is performed to the outer peripheral portion of the substrate W. In addition, since the inner peripheral portion 241 of the sealing belt 201 is closer to the substrate W than the first upper surface 200, the electrostatic attraction to the substrate W is greater at the inner peripheral portion 241 of the sealing belt 201 than at the center (the portion having the first upper surface 200). Therefore, the contact pressure (adsorption force per unit area) between the substrate W and the outer peripheral portion 240 increases, and the substrate W is strongly adsorbed to the outer peripheral portion 240. As a result, a small gap that may be generated between the substrate W and the outer peripheral portion 240 due to surface roughness or the like is reduced, and the contact area between the substrate W and the outer peripheral portion 240 is increased, so that heat is efficiently transferred between the electrostatic chuck 1111 and the outer peripheral portion of the substrate W. As a result of the above, during the plasma treatment, the outer peripheral portion of the substrate W can be sufficiently cooled, and the temperature uniformity of the substrate held on the electrostatic chuck 1111 can be improved.

[0094] <Example>

[0095] (1) As an example, in the case where the inner peripheral portion 241 is lower than the outer peripheral portion 240 of the sealing tape 201 as in the embodiment shown in this example, (2) As a comparative example, in the case where the inner peripheral portion 241 is lower than the outer peripheral portion 240 of the sealing tape 201 as in the embodiment shown in this example, Figure 6 As shown in FIG. 1 , when the sealing tape 201 has an inner peripheral portion 500 having the same height as the outer peripheral portion 240, (3) as a comparative example, Figure 7As shown, the sealing tape 201 has an inner peripheral portion 501 of the same height as the first upper surface 200, and the contact pressure of the sealing tape 201 on the substrate is compared. In addition, the radial width X of the outer peripheral portion 240 is 1.7 mm, and the radial width X of the inner peripheral portion 241 (500, 501) is 1.8 mm. In addition, in (1), the difference ΔH between the height of the third upper surface 260 and the second upper surface 250 is 5 μm. In the case of (2), compared with the case of (1), the radial width of the outer peripheral portion 240 of the sealing tape 20 is substantially larger, and the contact area between the substrate W and the sealing tape 201 is larger. In the case of (3), compared with the case of (1), the contact area between the substrate W and the sealing tape 201 is the same, and the distance between the inner peripheral portion 501 and the substrate W is larger. The result of applying the same voltage to the electrostatic electrodes 1111b of (1) to (3) was that the contact pressure was 17.7 kPa in (1), 14.3 kPa in (2), and 16.0 kPa in (3). As a result, it was confirmed that in the case of (1), heat was transferred between the substrate W and the sealing tape 201 compared with the cases of (2) and (3). In fact, the electrostatic chuck 1111 was used to hold the substrate W, and the temperature of the outer periphery of the substrate W when the substrate W was cooled from the electrostatic chuck 1111 was measured. In the case of (1), a low temperature effect of about 1.5°C to 2.2°C was obtained compared with the cases of (2) and (3).

[0096] In the above embodiment, the upper surface of the inner circumference 241 of the sealing tape 201 only has the third upper surface 260, but it may also have an inclined surface. Fig. 9 As shown, the upper surface of the inner circumference 241 of the sealing tape 201 has a third upper surface 260 and an inclined surface 310. The inclined surface 310 and the third upper surface 260 may be connected to each other. The inclined surface 310 may be connected to the first upper surface 200 at one end and to the third upper surface 260 at the other end. In one embodiment, Fig.10 As shown, one end of the inclined surface 310 is connected to the second upper surface 250 , and the other end is connected to the third upper surface 260 .

[0097] In one embodiment, the Fig.11 As shown, the upper surface of the inner peripheral portion 241 of the sealing tape 201 is an inclined surface 310 as a whole.

[0098] In one embodiment, the Fig.12As shown, the inner circumference 241 of the sealing band 201 has an inclined upper surface 320 and a vertical surface 321 connected to each other in the radial direction X. The inclined upper surface 320 may be connected to the first upper surface 200 at one end and to the vertical surface 321 at the other end. The vertical surface 321 may be connected to the inclined upper surface 320 at one end and to the second upper surface 250 at the other end.

[0099] In one embodiment, the Fig.13 As shown, one end of the vertical surface 321 is connected to the first upper surface 200, and the other end is connected to the inclined upper surface 320. The inclined upper surface 320 may be connected to the vertical surface 321 at one end, and connected to the second upper surface 250 at the other end.

[0100] By having an inclined surface, Figure 5 Compared with the case where only the flat third upper surface 260 is provided as shown, the electrostatic attraction to the substrate W can be increased, and the substrate W can be strongly adsorbed to the outer peripheral portion 240 .

[0101] In the above embodiment, the electrostatic chuck 1111 is used in a capacitively coupled plasma device, but the present invention is not limited thereto and may be used in other types of plasma devices. In addition, the electrostatic chuck 1111 is not limited to plasma processing devices and may be used in other substrate processing devices.

[0102] The embodiments of the present invention include the following aspects.

[0103] (Note 1)

[0104] An electrostatic chuck for holding a substrate, comprising:

[0105] a dielectric member for mounting the substrate; and

[0106] an electrostatic electrode disposed in the dielectric component,

[0107] The dielectric component comprises:

[0108] A first upper surface having a gas outflow portion for gas to flow out; and

[0109] an annular sealing belt, which is arranged outside the first upper surface and has a height higher than the first upper surface,

[0110] The sealing tape comprises:

[0111] Peripheral part; and

[0112] an inner peripheral portion having a lower height than the outer peripheral portion,

[0113] The electrostatic electrode is disposed at least directly below the inner peripheral portion of the sealing band.

[0114] (Note 2)

[0115] The electrostatic chuck as described in Appendix 1, wherein:

[0116] The outer peripheral portion of the sealing tape has a flat second upper surface,

[0117] The inner peripheral portion of the sealing tape has a flat third upper surface.

[0118] (Note 3)

[0119] The electrostatic chuck as described in Appendix 2, wherein:

[0120] The upper surface of the inner peripheral portion of the sealing tape further has an inclined surface.

[0121] (Note 4)

[0122] The electrostatic chuck according to Appendix 2 or 3, wherein:

[0123] The third upper surface is lower than the second upper surface and higher than the first upper surface.

[0124] (Note 5)

[0125] The electrostatic chuck according to any one of Supplementary Notes 2 to 4, wherein

[0126] The third upper surface is lower than the second upper surface by more than 0.1 μm.

[0127] (Note 6)

[0128] The electrostatic chuck according to any one of Supplementary Notes 2 to 5, wherein

[0129] The third upper surface is higher than the first upper surface by more than 3 μm.

[0130] (Note 7)

[0131] The electrostatic chuck according to any one of Supplementary Notes 2 to 6, wherein

[0132] A distance from the third upper surface to the electrostatic electrode is in a range of 100 μm to 750 μm.

[0133] (Note 8)

[0134] The electrostatic chuck according to any one of Supplementary Notes 2 to 7, wherein

[0135] The upper surface of the inner peripheral portion of the sealing tape includes only the third upper surface.

[0136] (Note 9)

[0137] The electrostatic chuck according to any one of appendices 1 to 8, wherein

[0138] The dielectric member further includes a plurality of protrusions that are arranged on the first upper surface and protrude upward relative to the first upper surface.

[0139] (Note 10)

[0140] The electrostatic chuck as described in Appendix 9, wherein:

[0141] The convex portion has a height that is the same as or lower than the outer peripheral portion of the sealing band.

[0142] (Note 11)

[0143] The electrostatic chuck according to Supplement 9 or 10, wherein:

[0144] The convex portion has a height in the range of 5 μm to 50 μm.

[0145] (Note 12)

[0146] The electrostatic chuck according to any one of appendices 9 to 11, wherein

[0147] The inner end portion of the inner peripheral portion of the sealing band is located between the outer end portion of the outermost convex portion and the inner end portion of the outer peripheral portion of the sealing band.

[0148] (Note 13)

[0149] The electrostatic chuck according to any one of appendices 9 to 12, wherein

[0150] The inner end portion of the inner peripheral portion of the sealing band is located inside a radially intermediate point between the outer end portion of the outermost convex portion and the inner end portion of the outer peripheral portion of the sealing band.

[0151] (Note 14)

[0152] The electrostatic chuck according to any one of Supplementary Notes 9 to 13, wherein

[0153] The inner peripheral portion of the sealing band has a height that is equal to or greater than half the height of the convex portion.

[0154] (Note 15)

[0155] The electrostatic chuck according to any one of appendices 1 to 14, wherein

[0156] The electrostatic electrode is arranged from directly below the first upper surface to directly below the sealing belt.

[0157] The outer end portion of the electrostatic electrode is located outside the radial center of the inner peripheral portion of the sealing band.

[0158] (Note 16)

[0159] The electrostatic chuck as described in Appendix 15, wherein:

[0160] The electrostatic electrode has an outer end portion located directly below the outer peripheral portion of the sealing band.

[0161] (Note 17)

[0162] The electrostatic chuck according to any one of Supplementary Notes 1 to 16, wherein

[0163] The outer peripheral portion of the sealing band has a radial width in a range of 0.3 mm to 4 mm.

[0164] (Note 18)

[0165] The electrostatic chuck according to any one of appendices 1 to 17, wherein

[0166] The inner peripheral portion of the sealing band has a radial width in a range of 1 mm to 36 mm.

[0167] (Note 19)

[0168] The electrostatic chuck according to any one of Supplementary Notes 1 to 18, wherein

[0169] The radial width of the inner peripheral portion of the sealing band is greater than the radial width of the outer peripheral portion of the sealing band.

[0170] (Note 20)

[0171] The electrostatic chuck according to any one of appendices 1 to 19, wherein

[0172] The upper surface of the inner peripheral portion of the sealing tape is an inclined surface as a whole.

[0173] (Note 21)

[0174] The electrostatic chuck according to any one of appendices 1 to 20, wherein

[0175] The inner peripheral portion of the sealing band has an inclined upper surface and a vertical surface connected to each other in a radial direction.

[0176] (Note 22)

[0177] The electrostatic chuck according to any one of appendices 1 to 21, wherein

[0178] The dielectric member has a thickness in a vertical direction in a range of 0.5 mm to 5 mm.

[0179] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present invention. The above embodiments can be variously modified without departing from the scope and purpose of the present invention. For example, a part of the components in one embodiment can be added to other embodiments. In addition, a part of the components in one embodiment can be replaced with corresponding components in other embodiments.

[0180] Description of Reference Numerals

[0181] 1: plasma processing device, 10: chamber, 11: substrate supporting part, 112: ring assembly, 1111: electrostatic suction cup, 1111a: ceramic component, 1111b: electrostatic electrode, 200: first upper surface, 201: sealing belt, 240: outer peripheral part, 241: inner peripheral part, 250: second upper surface, 260: third upper surface, W: substrate.

Claims

1. An electrostatic chuck for holding a substrate, comprising: A dielectric member for mounting a substrate; and an electrostatic electrode disposed in the dielectric component, The dielectric component comprises: A first upper surface having a gas outflow portion for gas to flow out; and an annular sealing belt, which is arranged outside the first upper surface and has a height higher than the first upper surface, The sealing tape comprises: Peripheral part; and an inner peripheral portion having a lower height than the outer peripheral portion, The electrostatic electrode is disposed at least directly below the inner peripheral portion of the sealing band.

2. The electrostatic chuck according to claim 1, wherein: The outer peripheral portion of the sealing tape has a flat second upper surface, The inner peripheral portion of the sealing tape has a flat third upper surface.

3. The electrostatic chuck according to claim 2, wherein: The upper surface of the inner peripheral portion of the sealing tape further has an inclined surface.

4. The electrostatic chuck according to claim 2, wherein: The third upper surface is lower than the second upper surface and higher than the first upper surface.

5. The electrostatic chuck according to claim 4, wherein: The third upper surface is lower than the second upper surface by more than 0.1 μm.

6. The electrostatic chuck according to claim 5, wherein: The third upper surface is higher than the first upper surface by more than 3 μm.

7. The electrostatic chuck according to claim 2, wherein: A distance from the third upper surface to the electrostatic electrode is in a range of 100 μm to 750 μm.

8. The electrostatic chuck according to claim 2, wherein: The upper surface of the inner peripheral portion of the sealing tape includes only the third upper surface.

9. The electrostatic chuck according to claim 1, wherein: The dielectric member further includes a plurality of protrusions that are arranged on the first upper surface and protrude upward relative to the first upper surface.

10. The electrostatic chuck according to claim 9, wherein: The convex portion has a height that is the same as or lower than the outer peripheral portion of the sealing band.

11. The electrostatic chuck according to claim 9, wherein: The convex portion has a height in the range of 5 μm to 50 μm.

12. The electrostatic chuck of claim 9, wherein: The inner end portion of the inner peripheral portion of the sealing band is located between the outer end portion of the outermost convex portion and the inner end portion of the outer peripheral portion of the sealing band.

13. The electrostatic chuck of claim 12, wherein: The inner end portion of the inner peripheral portion of the sealing band is located inward of a radially intermediate point between the outer end portion of the outermost convex portion and the inner end portion of the outer peripheral portion of the sealing band.

14. The electrostatic chuck of claim 9, wherein: The inner peripheral portion of the sealing band has a height that is equal to or greater than half the height of the convex portion.

15. The electrostatic chuck of claim 1, wherein: The electrostatic electrode is arranged from directly below the first upper surface to directly below the sealing belt. The outer end portion of the electrostatic electrode is located outside the radial center of the inner peripheral portion of the sealing band.

16. The electrostatic chuck of claim 15, wherein: The electrostatic electrode has an outer end portion located directly below the outer peripheral portion of the sealing band.

17. The electrostatic chuck of claim 1, wherein: The outer peripheral portion of the sealing band has a radial width in a range of 0.3 mm to 4 mm.

18. The electrostatic chuck of claim 1, wherein: The inner peripheral portion of the sealing band has a radial width in a range of 1 mm to 36 mm.

19. The electrostatic chuck of claim 1, wherein: The radial width of the inner peripheral portion of the sealing band is greater than the radial width of the outer peripheral portion of the sealing band.

20. The electrostatic chuck of claim 1, wherein: The upper surface of the inner peripheral portion of the sealing tape is an inclined surface as a whole.

21. The electrostatic chuck of claim 1, wherein: The inner peripheral portion of the sealing band has an inclined upper surface and a vertical surface connected to each other in a radial direction.

22. The electrostatic chuck of claim 1, wherein: The dielectric member has a thickness in a vertical direction in a range of 0.5 mm to 5 mm.

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