Upper top plate and substrate processing device

Abstract

This upper top plate is disposed on an upper part of a chamber and includes: a base; an upper electrode disposed on a lower surface side of the base; and a heat conduction medium provided between the lower surface of the base and an upper surface of the upper electrode and filled in a heat transfer space surrounded by a seal material. The base is provided such that in the lower surface which is in contact with the heat transfer space, a buffer space is formed that communicates with the heat transfer space, and the heat conduction medium is also filled in a part of the buffer space.

Description

Upper top plate and substrate processing device

[0001] The present disclosure relates to an upper top plate and a substrate processing apparatus.

[0002] It is disclosed that in an electrode assembly, the thermally conductive gasket comprises a composite of aluminum foil coated with thermally and electrically conductive rubber, and that the thermally conductive gasket is composed of a carbon nanotube filler (Patent Document 1).

[0003] U.S. Patent No. 8,216,418

[0004] The present disclosure provides an upper top plate and a substrate processing apparatus that can maintain good thermal conduction even when the base is deformed by heat input.

[0005] An upper top plate according to one aspect of the present disclosure is an upper top plate that is placed on top of a chamber, and has a base, an upper electrode that is placed on the underside of the base, and a heat conduction medium that is provided between the underside of the base and the upper surface of the upper electrode and filled in a heat transfer space surrounded by a sealing material, and a buffer space that communicates with the heat transfer space is formed on the underside of the base that contacts the heat transfer space, and the heat conduction medium is also filled in a portion of the buffer space.

[0006] According to the present disclosure, good thermal conduction can be maintained even if the base is deformed by heat input.

[0007] FIG. 1 is a diagram illustrating an example of a plasma processing apparatus according to an embodiment of the present disclosure. FIG. 2 is a perspective view illustrating an example of an upper electrode according to this embodiment. FIG. 3 is a cross-sectional view illustrating an example of a heat transfer space according to this embodiment. FIG. 4 is a cross-sectional view illustrating another example of a heat transfer space according to this embodiment. FIG. 5 is a cross-sectional view illustrating an example of a state of a heat transfer space during deformation according to this embodiment. FIG. 6 is a cross-sectional view illustrating another example of a buffer space according to this embodiment. FIG. 7 is a cross-sectional view illustrating another example of a buffer space according to this embodiment.

[0008] Hereinafter, embodiments of the disclosed upper top plate and substrate processing apparatus will be described in detail with reference to the drawings. However, the disclosed technology is not limited to the following embodiments.

[0009] In a plasma processing apparatus, an upper top plate is provided at the top of the chamber, and includes an upper electrode facing the interior of the chamber and a cooling plate (hereinafter also referred to as a base) for cooling the upper electrode. A heat transfer medium with good thermal conductivity, such as a heat transfer sheet (thermal conduction sheet), is provided between the upper electrode and the cooling plate, and heat input from the plasma is transferred from the upper electrode to the cooling plate. However, as the plasma power increases, the amount of heat input to each part of the chamber increases, and the amount of deformation of the cooling plate due to atmospheric pressure and heat input increases. When the cooling plate deforms, there may be areas where the heat transfer medium provided between the upper electrode and the cooling plate is not in contact. This deteriorates the thermal conduction between the upper electrode and the cooling plate. Therefore, it is expected that the cooling plate (base) will maintain good thermal conduction even when deformed by heat input.

[0010] [Configuration of Plasma Processing System] An exemplary configuration of a plasma processing system will be described below. FIG. 1 illustrates an example of a plasma processing apparatus according to an embodiment of the present disclosure. As shown in FIG. 1, the plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a controller 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a chiller unit 17, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas inlet for supplying at least one processing gas into the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0011] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0012] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0013] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0014] The substrate support 11 may also include a temperature adjustment module configured to adjust 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 passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0015] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 is supported on the upper part of the plasma processing chamber 10 via an insulating shielding member 19. The showerhead 13 includes a cooling plate (base) 14 and an upper electrode 18. The upper electrode 18 has a plurality of ejection holes 18a that penetrate the upper electrode 18 in the thickness direction and eject the processing gas into the plasma processing chamber 10.

[0016] The cooling plate 14 is made of a conductive material and detachably supports the upper electrode 18 at its lower portion. The cooling plate 14 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The multiple gas inlets 13c are connected to multiple discharge holes 18a. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c and the multiple discharge holes 18a. In addition to the showerhead 13, the gas inlet may include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0017] A flow path 15 is provided inside the cooling plate 14, and a coolant is supplied into the flow path 15 via a pipe 16 from a chiller unit 17 provided outside the plasma processing chamber 10. The coolant supplied from the chiller unit 17 through the pipe 16 into the flow path 15 of the cooling plate 14 circulates within the flow path 15 and is returned to the chiller unit 17 via the pipe 16. The chiller unit 17 controls the temperature of the coolant supplied into the flow path 15. The chiller unit 17 is an example of a temperature control unit. Circulating the temperature-controlled coolant through the flow path 15 suppresses a temperature rise in the shower head 13 due to heat input from the plasma generated between the substrate support 11 and the shower head 13. The cooling plate 14 may not have a flow path inside, but may suppress a temperature rise in the shower head 13 using an air-cooling method that exchanges heat with the atmosphere outside the plasma processing chamber 10, or a water-cooled jacket, Peltier element, or the like attached to the outside.

[0018] The upper electrode 18 is made of a conductive material such as silicon, SiC, etc. Instead of the upper electrode 18, a plate made of a dielectric material such as quartz or ceramic and having a plurality of discharge holes formed therein, each of which communicates with the plurality of gas inlets 13c, may be detachably supported below the cooling plate 14.

[0019] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0020] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0021] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0022] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0023] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0024] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0025] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0026] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0027] [Details of the Upper Electrode and Heat Transfer Space] Next, the upper electrode 18 and the heat transfer space, as well as the state of the heat transfer space when the cooling plate is deformed, will be described using FIGS. 2 to 5 . FIG. 2 is a perspective view showing an example of an upper electrode in this embodiment. As shown in FIG. 2 , seals 50 and 51 of different diameters are provided circumferentially on the outer periphery of the upper surface 18b of the upper electrode 18, which contacts the cooling plate 14. The seal 51 is disposed on the inner periphery side of the seal 50. The seals 50 and 51 are, for example, lip seals, and prevent deterioration and consumption of the heat transfer medium. A heat transfer sheet 52 is provided between the seals 50 and 51. The heat transfer sheet 52 can be, for example, a heat transfer sheet based on silicon, metals such as aluminum, graphite, or resin. Note that the discharge holes 18a of the upper electrode 18 are omitted from FIG. 2 .

[0028] FIG. 3 is a cross-sectional view showing an example of a heat transfer space in this embodiment. FIG. 3 illustrates the vicinity of the seal materials 50 and 51 in a cross section of the shower head 13 in which the upper electrode 18 is attached to the cooling plate 14. As shown in FIG. 3 , in this embodiment, the cooling plate 14 has a structure that can be separated into a lower member 14a and an upper member 14b. The cooling plate 14 may also have a structure in which the lower member 14a and the upper member 14b are integrated. A heat transfer space 53 surrounded by the seal materials 50 and 51 is formed between the lower surface of the lower member 14a and the upper surface of the upper electrode 18. The heat transfer sheet 52 shown in FIG. 2 is disposed within the heat transfer space 53. A buffer space 54 that communicates with the heat transfer space 53 is formed on the lower surface of the lower member 14a, which contacts the heat transfer space 53. The upper member 14b has a through-hole 56 that penetrates from the upper surface to the lower surface of the upper member 14b and communicates with the buffer space 54.

[0029] The heat transfer space 53 is filled with a fluid 55. The fluid 55 fills the gap between the heat transfer sheet 52 and the lower surface of the lower member 14a in the heat transfer space 53, and also fills a portion of the buffer space 54 communicating with the heat transfer space 53. In other words, the heat transfer sheet 52 and the fluid 55 are an example of a heat conduction medium. The fluid 55 is a liquid substance, and may be, for example, a heat transfer vacuum grease that has low volatility in a vacuum atmosphere. Examples of the vacuum grease that may be used include silicone-based, fluorine-based, and metal-based vacuum greases. The fluid 55 is applied in advance between the sealants 50 and 51 of the upper electrode 18, for example, during assembly of the showerhead 13. When the upper electrode 18 is pressed against the cooling plate 14, the fluid 55 fills the heat transfer space 53 and is partially pushed out into the buffer space 54. After the showerhead 13 is assembled, the fluid 55 may be filled into the heat transfer space 53 using the through-hole 56 communicating with the buffer space 54 of the upper member 14b and the buffer space 54 as injection paths. The through-hole 56 does not communicate with the gas diffusion chamber 13b or the gas inlet 13c. The upper part of the through-hole 56 is not sealed with a cap.

[0030] FIG. 4 is a cross-sectional view showing another example of a heat transfer space in this embodiment. The showerhead 13 shown in FIG. 4 illustrates a state in which the upper portion of the through-hole 56 is sealed with a cap 56a, as compared to the showerhead 13 in FIG. 3 . That is, the through-hole 56 may or may not be sealed with the cap 56a. Furthermore, when the through-hole 56 is sealed with the cap 56a, it is desirable to provide a vent hole in the cap 56a or elsewhere in the upper member 14b, which vents gas such as air present in the buffer space 54 and the through-hole 56 to the outside (not shown) when part of the fluid 55 is pushed into the buffer space 54.

[0031] The buffer spaces 54 are, for example, slit-shaped or hole-shaped, and multiple buffer spaces 54 are provided in the lower member 14a above the ring-shaped heat transfer space 53. The slit-shaped buffer spaces 54 refer to a shape having a cross section such as an elongated rectangle or an arc when viewed from above the cooling plate 14. The hole-shaped buffer spaces 54 refer to a shape having a cross section such as a circle or a square when viewed from above the cooling plate 14. In this case, the buffer spaces 54 may be provided, for example, at equal intervals on a circumference. Sealing materials 14c and 14d are provided on the outside and inside of the buffer spaces 54 between the lower member 14a and the upper member 14b, respectively, to maintain the airtightness of the plasma processing space 10s.

[0032] FIG. 5 is a cross-sectional view showing an example of the state of the heat transfer space during deformation in this embodiment. FIG. 5 illustrates the vicinity of the sealants 50 and 51 of the shower head 13 when the cooling plate 14 is deformed due to plasma heat input. As shown in FIG. 5 , a gap 58 is generated around the periphery of the shower head 13 between the lower surface of the lower member 14a and the upper surface of the upper electrode 18 due to the deformation of the cooling plate 14. At this time, the vertical spacing in the heat transfer space 53 widens, creating a gap. However, the fluid 55 filled in the buffer space 54 fills the gap due to gravity. Furthermore, the temperature of the fluid 55 increases due to heat input, reducing its viscosity, making it easier to fill the gap. The sealants 50 and 51 seal the fluid 55 to prevent leakage to the outside even when the gap 58 is generated. Furthermore, because the buffer space 54 and the atmospheric space above the upper member 14b are at the same pressure, the pressure in the buffer space 54 does not impede the movement of the fluid 55, and the fluid 55 does not impede its movement into the heat transfer space 53.

[0033] When the heat input from the plasma ceases from the state shown in Fig. 5, the state returns to the state shown in Fig. 3. At this time, the deformation caused by the heat input returns to its original state, and the excess fluid 55 returns from the heat transfer space 53 to the buffer space 54. In this way, in this embodiment, even if the cooling plate 14 deforms due to the heat input, the contact area with the upper electrode 18 is maintained by the heat transfer sheet 52 and the fluid 55 in the heat transfer space 53, so good heat conduction can be maintained.

[0034] In this embodiment, the circular cooling plate 14 is assumed to deform such that its center becomes convex downward. Therefore, when this deformation occurs, a gap forms between the cooling plate 14 and the upper electrode 18 at the peripheral portion, where a ring-shaped heat transfer space 53 surrounded by the sealants 50 and 51 ensures a sufficient contact area for heat transfer. For example, the contact area between the cooling plate 14 and the upper electrode 18 is assumed to be approximately 50% of the area of ​​the lower surface of the cooling plate 14 and the upper surface of the upper electrode 18. In this case, if the contact area is reduced to 10% due to deformation, heat transfer capacity is significantly reduced and the temperature of the upper electrode 18 cannot be maintained using only the heat transfer sheet. In contrast, in this embodiment, the heat transfer sheet 52 and the fluid 55 are used in combination, allowing a 50% contact area to be maintained. If the fluid 55 has a high thermal conductivity, the heat transfer sheet 52 may be omitted from the heat transfer medium, and only the fluid 55 may be used.

[0035] 3 and 5, the atmospheric space and the buffer space 54 are connected by the through-hole 56, but this is not limiting. For example, instead of providing the through-hole 56, a gap or a communication hole communicating with the gas diffusion chamber 13b or the plasma processing space 10s may be provided. This ensures that the buffer space 54 and the gas diffusion chamber 13b or the plasma processing space 10s have the same pressure, so that the movement of the fluid 55 is not hindered by the pressure in the buffer space 54 and the movement of the fluid 55 to the heat transfer space 53 is not hindered. When the buffer space 54 is connected to the gas diffusion chamber 13b or the plasma processing space 10s, it is desirable that the fluid 55 used has no volatility or very little volatility at the pressure of the gas diffusion chamber 13b or the plasma processing space 10s. Furthermore, if the through-holes 56 are not provided, the fluid 55 may be filled into the heat transfer space 53 after the shower head 13 is assembled, using the gaps and communication holes communicating with the gas diffusion chamber 13b or the plasma processing space 10s and the buffer space 54 as injection paths.

[0036] In the above embodiment, the cross-sectional area of ​​the buffer space 54 is the same throughout the entire area in the vertical direction, but the cross-sectional area of ​​the buffer space 54 may be larger at the top or bottom, and this case will be described as a modified example. Note that the plasma processing apparatus in the modified example is similar to the above embodiment, so a description of the configuration and operation thereof will be omitted.

[0037] 6 and 7 are cross-sectional views showing another example of the buffer space in this embodiment. The shower head 13d shown in FIG. 6 uses a lower member 14e instead of the lower member 14a. A buffer space 54a is formed in the lower member 14e. The buffer space 54a is formed so that its lower portion (the heat transfer space 53 side) has a larger cross-sectional area than the upper portion of the buffer space 54a, as shown in region 60. Region 60 may have a tapered shape or another shape, such as a stepped shape. Providing region 60 makes it easier for the fluid 55 in the buffer space 54a to fill the heat transfer space 53. Furthermore, the amount of fluid 55 stored in the heat transfer space 53 and the buffer space 54a can be increased.

[0038] The shower head 13e shown in FIG. 7 uses a lower member 14f instead of the lower member 14a. A buffer space 54b is formed in the lower member 14f. The buffer space 54b is formed so that its upper portion (opposite the heat transfer space 53) has a larger cross-sectional area than the lower portion of the buffer space 54b, as shown in region 61. Note that, like region 60, region 61 may have a tapered shape or other shape, such as a stepped shape. Providing region 61 increases the amount of fluid 55 stored in the heat transfer space 53 and the buffer space 54b. The radial width of the upper portion of the buffer space 54b, i.e., the radial width of the buffer space 54b on the upper surface of the lower member 14f, is smaller than the gap between the sealant 14c and the sealant 14d, thereby maintaining the airtightness of the plasma processing space 10s.

[0039] It is preferable to determine whether to use the lower member 14e of the shower head 13d or the lower member 14f of the shower head 13e depending on the thermal conductivity of the heat conduction medium. For example, if the thermal conductivity of the heat transfer sheet 52 is lower than that of the fluid 55, it is preferable to use the lower member 14e. On the other hand, if the thermal conductivity of the heat transfer sheet 52 is higher than that of the fluid 55, it is preferable to use the lower member 14f. In other words, if the lower member 14f is used, the contribution of the fluid 55 is reduced. Note that the lower member 14e and the lower member 14f may be combined to increase the cross-sectional areas of the upper and lower portions of the buffer space 54.

[0040] In the above embodiment, the heat transfer space 53 is formed in a ring shape, but is not limited to this. For example, the heat transfer space 53 may be formed in the shape of a plurality of independent islands in the circumferential direction of the cooling plate 14 and the upper electrode 18. This makes it possible to form the heat transfer space 53 while easily avoiding the connection between the flow path 15 and the piping 16 inside the cooling plate 14, the gas supply port 13a, etc.

[0041] As described above, according to this embodiment, the upper top plate (shower head 13) is an upper top plate disposed at the top of the chamber (plasma processing chamber 10), and includes a base (cooling plate 14), an upper electrode 18 disposed on the underside of the base and facing the interior of the chamber, and a heat conduction medium (fluid 55) provided between the underside of the base and the upper surface of the upper electrode 18 and filled in a heat transfer space 53 surrounded by sealants 50 and 51. A buffer space 54 communicating with the heat transfer space 53 is formed on the underside of the base that contacts the heat transfer space 53, and the heat conduction medium is also filled in a portion of the buffer space 54. As a result, good heat conduction can be maintained even if the base is deformed due to heat input.

[0042] According to this embodiment, the heat transfer medium contains a liquid substance, so that even if deformation due to heat input is repeated, the heat transfer space 53 is filled with the heat transfer medium each time, thereby maintaining good heat conduction.

[0043] Furthermore, according to this embodiment, the heat transfer medium includes the heat transfer sheet 52 disposed in the heat transfer space 53. As a result, the required amount of fluid 55 can be reduced.

[0044] Furthermore, in this embodiment, the liquid substance is vacuum grease, and as a result, even if the buffer space 54 is in a vacuum atmosphere, evaporation of the vacuum grease (fluid 55) can be suppressed.

[0045] Furthermore, according to this embodiment, the buffer space 54 is connected to an injection path (through-hole 56) that communicates with the outside of the base. As a result, the fluid 55 can be filled into the heat transfer space 53 even after the showerhead 13 is assembled.

[0046] Furthermore, according to this embodiment, the injection path communicates with the interior of the chamber, so that the movement of the fluid 55 from the buffer space 54 to the heat transfer space 53 is not impeded.

[0047] Furthermore, according to this embodiment, the internal pressure of the buffer space 54 changes depending on the internal pressure of the chamber, so that the movement of the fluid 55 from the buffer space 54 to the heat transfer space 53 is not impeded.

[0048] In addition, according to this embodiment, the buffer space 54 has a slit shape, so that the fluid 55 can be stored.

[0049] In addition, according to this embodiment, the buffer space 54 is hole-shaped, so that the fluid 55 can be stored.

[0050] Furthermore, according to this embodiment, the buffer space 54a is formed so that the cross-sectional area thereof is larger on the side of the heat transfer space 53. As a result, the fluid 55 in the buffer space 54a is more likely to fill the heat transfer space 53.

[0051] Furthermore, according to this embodiment, the buffer space 54b is formed so that the cross-sectional area is larger on the side opposite to the heat transfer space 53. As a result, it is possible to increase the amount of fluid 55 stored in the heat transfer space 53 and the buffer space 54b.

[0052] Furthermore, according to this embodiment, the heat transfer space 53 is formed in a ring shape in the circumferential direction of the base, thereby ensuring a sufficient contact area between the cooling plate 14 and the upper electrode 18.

[0053] Furthermore, according to this embodiment, the heat transfer spaces 53 are formed as a plurality of independent islands in the circumferential direction of the base, which allows the heat transfer spaces to be formed while easily avoiding the connection between the flow passages 15 and the piping 16 inside the cooling plate 14, the gas supply port 13 a, etc.

[0054] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and various omissions, substitutions, and modifications may be made to the above-described embodiments without departing from the scope and spirit of the appended claims.

[0055] In the above embodiment, the plasma processing apparatus 1 is described as an example in which a process such as etching is performed on a substrate W using capacitively coupled plasma as a plasma source, but the disclosed technology is not limited to this. As long as the apparatus performs a process on a substrate W using plasma, the plasma source is not limited to capacitively coupled plasma, and any plasma source such as inductively coupled plasma, microwave plasma, or magnetron plasma can be used.

[0056] In the above embodiment, the plasma processing apparatus 1 is used as an example of a substrate processing apparatus, but the present invention is not limited to this. For example, the present invention may be applied to a thermal CVD (Chemical Vapor Deposition) apparatus that does not use plasma.

[0057] In the above embodiment, the heat transfer space 53 is provided on the periphery of the cooling plate 14, but this is not limiting. For example, depending on the method of fixing the upper electrode 18 to the cooling plate 14, the heat transfer space 53 may be provided in a location where a gap occurs due to deformation of the cooling plate 14. For example, if a gap occurs in the center of the cooling plate 14, the heat transfer space 53 may be provided in the center.

[0058] In the above embodiment, the heat transfer space 53 is provided between the lower surface of the cooling plate 14 and the upper surface of the upper electrode 18, but this is not limiting. For example, if the cooling plate 14 is divided into a lower member 14a and an upper member 14b, the heat transfer space 53 may be provided between the upper surface of the lower member 14a and the lower surface of the upper member 14b. In this case, the upper member 14b serves as a base, and the lower member 14a can be considered as part of the upper electrode.

[0059] The present disclosure may also be configured as follows. (1) An upper top plate disposed above a chamber, comprising: a base; an upper electrode disposed on the underside of the base; and a heat conduction medium filled in a heat transfer space provided between the underside of the base and the upper surface of the upper electrode and surrounded by a sealant, wherein the base has a buffer space formed on its underside that contacts the heat transfer space and that communicates with the heat transfer space, and the heat conduction medium also fills a portion of the buffer space. (2) The upper top plate described in (1), wherein the heat conduction medium includes a liquid substance. (3) The upper top plate described in (2), wherein the heat conduction medium includes a heat transfer sheet disposed in the heat transfer space. (4) The upper top plate described in (2) or (3), wherein the liquid substance is vacuum grease. (5) The upper top plate described in any one of (1) to (4), wherein the buffer space is connected to an injection path that communicates with the outside of the base. (6) The top upper plate according to (5), wherein the injection path is in communication with the interior of the chamber. (7) The top upper plate according to (6), wherein the internal pressure of the buffer space changes according to the internal pressure of the chamber. (8) The top upper plate according to any one of (1) to (7), wherein the buffer space is slit-shaped. (9) The top upper plate according to any one of (1) to (7), wherein the buffer space is hole-shaped. (10) The top upper plate according to (8) or (9), wherein the buffer space is formed so that the cross-sectional area is larger on the heat transfer space side. (11) The top upper plate according to (8) or (9), wherein the cross-sectional area of ​​the buffer space is larger on the opposite side to the heat transfer space. (12) The top upper plate according to any one of (1) to (11), wherein the heat transfer space is formed in a ring shape in the circumferential direction of the base. (13) The upper top plate according to any one of (1) to (11), wherein the heat transfer spaces are formed in the shape of a plurality of independent islands in the circumferential direction of the base.(14) A substrate processing apparatus including: a chamber; and an upper top plate arranged above the chamber, wherein the upper top plate has: a base; an upper electrode arranged on the underside of the base; and a heat conduction medium provided between the underside of the base and the upper surface of the upper electrode and filled in a heat transfer space surrounded by a sealing material; wherein the base has a buffer space formed on its underside that contacts the heat transfer space and that communicates with the heat transfer space; and the heat conduction medium is also filled in a portion of the buffer space.

[0060] REFERENCE SIGNS LIST 1 Plasma processing apparatus 10 Plasma processing chamber 13 Shower head 14 Cooling plate (base) 15 Flow path 18 Upper electrode 50, 51 Sealing material 52 Heat transfer sheet 53 Heat transfer space 54, 54a, 54b Buffer space 55 Fluid 56 Through hole

Claims

1. An upper top plate placed on the top of a chamber, comprising: a base; an upper electrode placed on the underside of the base; and a heat conductive medium provided between the underside of the base and the upper surface of the upper electrode, the heat transfer space being surrounded by a sealing material and filled with the heat conductive medium, wherein a buffer space communicating with the heat transfer space is formed on the underside of the base that contacts the heat transfer space, and the heat conductive medium is also filled in a portion of the buffer space.

2. The upper top plate according to claim 1, wherein the heat conductive medium includes a liquid material.

3. The upper top plate according to claim 2, wherein the heat transfer medium includes a heat transfer sheet disposed within the heat transfer space.

4. The upper top plate according to claim 2 or 3, wherein the liquid substance is vacuum grease.

5. The upper top plate according to claim 1, wherein the buffer space is connected to an injection passage that communicates with the outside of the base.

6. The upper top plate according to claim 5, wherein the injection passage communicates with the interior of the chamber.

7. The upper top plate according to claim 6, wherein the buffer space has an internal pressure that changes according to the internal pressure of the chamber.

8. The upper top plate according to claim 1, wherein the buffer space is slit-shaped.

9. The upper top plate according to claim 1, wherein the buffer space is hole-shaped.

10. The upper top plate according to claim 8 or 9, wherein the buffer space is formed so that the cross-sectional area on the heat transfer space side is larger.

11. The upper top plate according to claim 8 or 9, wherein the buffer space is formed so that the cross-sectional area of ​​the buffer space is larger on the side opposite the heat transfer space.

12. The upper top plate according to claim 1, wherein the heat transfer space is formed in a ring shape in the circumferential direction of the base.

13. The upper top plate according to claim 1, wherein the heat transfer space is formed in the form of a plurality of independent islands in the circumferential direction of the base.

14. A substrate processing apparatus comprising: a chamber; and an upper top plate arranged on an upper portion of the chamber, wherein the upper top plate has a base; an upper electrode arranged on the underside of the base; and a heat conductive medium provided between the underside of the base and the upper surface of the upper electrode and filled in a heat transfer space surrounded by a sealing material, wherein a buffer space communicating with the heat transfer space is formed on the underside of the base that contacts the heat transfer space, and the heat conductive medium is also filled in a portion of the buffer space.