Substrate processing apparatus and cooling method

Abstract

Disclosed is a substrate processing apparatus which includes a member, a cooler, and a control unit. The member provides a flow path therein, the flow path having an inlet and an outlet. The cooler is configured so as to cool the member. The cooler includes a mist generator, a cold air supplier, and a decompression pump. The mist generator is configured so as to generate a mist of a cooling liquid, and is connected to the inlet of the flow path. The cold air supplier is connected to the inlet of the flow path. The decompression pump is connected to the outlet of the flow path. The control unit is configured to control the cooler so as to repeatedly execute processing that includes: (a) a step for supplying a mist from the mist generator to the flow path that is decompressed by the decompression pump; (b) a step for supplying a cold air from the cold air supplier to the flow path; and (c) a step for evacuating the flow path by the decompression pump.

Description

Substrate processing apparatus and cooling method

[0001] SUMMARY OF THE DISCLOSURE Exemplary embodiments of the present disclosure relate to substrate processing apparatus and cooling methods.

[0002] 2. Description of the Related Art Semiconductor manufacturing equipment is used in processing substrates. Japanese Patent Application Laid-Open No. 2003-144992 discloses a technique for supplying mist to a flow path in a chamber and cooling the chamber by the heat of vaporization of the mist.

[0003] Japanese Patent Application Laid-Open No. 2005-197600

[0004] The present disclosure provides a technique for efficiently cooling components within a substrate processing apparatus.

[0005] In one exemplary embodiment, a substrate processing apparatus is provided. The substrate processing apparatus includes a member, a cooler, and a controller. The member has a flow path therein, the flow path having an inlet and an outlet. The cooler is configured to cool the member. The cooler includes a mist generator, a cold air supplier, and a vacuum pump. The mist generator is configured to generate a mist of a cooling liquid and is connected to the inlet of the flow path. The cold air supplier is connected to the inlet of the flow path. The vacuum pump is connected to the outlet of the flow path. The controller is configured to control the cooler to repeatedly perform a process including: (a) supplying mist from the mist generator to the flow path whose pressure has been reduced by the vacuum pump; (b) supplying cold air from the cold air supplier to the flow path; and (c) evacuating the flow path with the vacuum pump.

[0006] According to one exemplary embodiment, a technique is provided for efficiently cooling components within a substrate processing apparatus.

[0007] FIG. 7 is a diagram for explaining an example of the configuration of a plasma processing system. FIG. 8 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus. FIG. 9 is a diagram for explaining a cooler according to an exemplary embodiment. FIG. 10 is a diagram for explaining an example of a mist generator that can be employed in a cooler according to an exemplary embodiment. FIG. 11 is a flowchart of a cooling method according to an exemplary embodiment. FIG. 12 is a timing chart of pressure in a flow channel in a cooling method according to an exemplary embodiment. Each of FIGS. 7(a) to 7(d) is a table showing an example of the states of various valves and various pumps in a cooling method according to an exemplary embodiment. Each of FIGS. 8(a) to 8(d) is a table showing an example of the states of various valves and various pumps in a cooling method according to an exemplary embodiment. Each of FIGS. 9(a) to 9(d) is a table showing an example of the states of various valves and various pumps in a cooling method according to an exemplary embodiment. Each of FIGS. 10(a) to 10(d) is a table showing an example of the states of various valves and various pumps in a cooling method according to an exemplary embodiment. 11A to 11F are diagrams illustrating examples of flow paths in a base according to an exemplary embodiment, and are diagrams illustrating modified examples of a plasma processing apparatus according to an exemplary embodiment.

[0008] Various exemplary embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0009] FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0010] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0011] 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).

[0012] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0013] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0014] 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.

[0015] 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 power supply 31 and / or a DC power supply 32, which will be 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, which will be 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.

[0016] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0017] 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.

[0018] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

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

[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 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 generation unit 12. 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 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, 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] Hereinafter, a cooler for a substrate processing apparatus according to one exemplary embodiment will be described with reference to FIG. 3 . FIG. 3 is a diagram showing a cooler according to one exemplary embodiment. The cooler 50 shown in FIG. 3 is configured to cool a member having a flow path in the substrate processing apparatus. In the example shown in FIG. 3 , the member cooled by the cooler 50 is the substrate support 11, more specifically, the base 1110. The cooler 50 includes a mist generator 51, a cold air supplier 52, and a decompression pump 53. The cooler 50 may further include a carrier gas supplier 54.

[0027] The mist generator 51 is configured to generate a mist CLM (see FIG. 4) of the coolant CL. The mist generator 51 can generate the mist CLM of the coolant CL from a reservoir 59, which will be described later. The coolant CL can include water, alcohol, ammonia, or a fluorine-based liquid. The water can be pure water, city water, or city water containing an additive such as a rust inhibitor. The alcohol can be, for example, an ethylene glycol aqueous solution. The fluorine-based liquid can include a fluorine-based inert liquid or a perfluoropolyether fluorine-based fluid.

[0028] The mist generator 51 is connected to an inlet 1110i of a flow path 1110a of the substrate support 11. The mist generator 51 may be connected to the inlet 1110i via a valve VM. The mist CLM generated by the mist generator 51 may be supplied to the flow path 1110a together with a carrier gas supplied from a carrier gas supply unit 54. The carrier gas is, for example, dry air.

[0029] FIG. 4 is a diagram illustrating an example mist generator that can be employed in a cooler according to an exemplary embodiment. In one embodiment, the mist generator 51 may be a spray nozzle atomization type mist generator, as shown in FIG. 4. In the embodiment of FIG. 4, the mist generator 51 includes an inner nozzle 51i and an outer nozzle 51o. The inner nozzle 51i is configured to spray a mist CLM of pressurized coolant CL therein from its orifice. The outer nozzle 51o provides a flow path for a carrier gas around the outer periphery of the inner nozzle 51i. The outer nozzle 51o provides its orifice in front of the orifice of the inner nozzle 51i. The flow path of the outer nozzle 51o extends to a position in front of the orifice of the inner nozzle 51i and is connected to the orifice of the outer nozzle 51o. According to the mist generator 51 shown in FIG. 4, the mist CLM injected from the orifice of the inner nozzle 51i is ejected together with the carrier gas from the orifice of the outer nozzle 51o and supplied to the flow path 1110a.

[0030] Returning to FIG. 3 , the cold air supplier 52 is connected to the inlet 1110i of the flow path 1110a. The cold air supplier 52 may be connected to the inlet 1110i via a valve VC. The cold air supplier 52 is configured to generate cold air from air supplied from the air supplier 55 and supply it to the flow path 1110a. The air supplied from the air supplier 55 is, for example, dry air. The cold air supplier 52 may be, for example, an air cooler. The cooler 50 may further include a pressure sensor 61. The pressure sensor 61 is configured to measure the pressure in the piping connecting each of the mist generator 51 and the cold air supplier 52 to the inlet 1110i.

[0031] The decompression pump 53 is connected to the outlet 1110o of the flow path 1110a. The decompression pump 53 may be connected to the outlet 1110o via a valve VE. The decompression pump 53 is configured to discharge the gas and the coolant CL (or its gas) in the flow path 1110a from the flow path 1110a. The decompression pump 53 may be, for example, a liquid ring pump. The cooler 50 may further include a pressure sensor 62. The pressure sensor 62 is configured to measure the pressure in a pipe connecting the decompression pump 53 and the outlet 1110o to each other.

[0032] According to the cooler 50, the cold air supplied from the cold air supplier 52 promotes condensation of the mist CLM in the flow path 1110a (adsorption onto the surface defining the flow path 1110a). Furthermore, the evaporation of the cooling liquid CL that has condensed in the flow path 1110a is promoted by the decompression (or vacuuming) of the flow path 1110a by the decompression pump 53. Therefore, the cooler 50 can efficiently cool the substrate support 11 or the base 1110. Furthermore, the heat exchange medium is not supplied to the flow path 1110a in a pressurized state. Therefore, the cooler 50 suppresses expansion of the substrate support 11 (or the base 1110).

[0033] In one embodiment, the cooler 50 may further include a trap 56 and a recovery device. The trap 56 is connected to the outlet 1110o via the pressure reducing pump 53. The trap 56 includes a tank. The trap 56 receives the mixture of gas and coolant CL (or its vapor) from the pressure reducing pump 53 in the tank. The trap 56 includes a separator 56s and is configured to separate the gas and the coolant CL by the separator 56s. The gas separated by the separator 56s is discharged to the outside via a filter 60. The coolant CL separated by the separator 56s is stored in the tank of the trap 56.

[0034] The collector is configured to collect and store the coolant CL, and is connected between the collector 56 and the mist generator 51. In one embodiment, the collector may include a receiver 57, a liquid circulation pump 58, and a reservoir 59. The receiver 57 has a tank for storing the coolant CL, and is connected between the collector 56 and the liquid circulation pump 58. The tank of the receiver 57 may be connected to the tank of the collector 56 via a valve RV. The reservoir 59 has another tank for storing the coolant CL, and is connected between the liquid circulation pump 58 and the mist generator 51. In this collector, the liquid circulation pump 58 is operated to return the coolant CL in the tank of the collector 56 to the tank of the reservoir 59 via the tank of the receiver 57 and the liquid circulation pump 58. The coolant CL returned to the reservoir 59 is reused in the mist generator 51 .

[0035] In one embodiment, the control unit 2 may be configured to adjust one or more of a plurality of control parameters for adjusting the temperature of a member such as the substrate support 11 by the cooler 50. The plurality of control parameters include the amount of mist CLM generated by the mist generator 51, the temperature of the mist CLM, the length of time the mist CLM is supplied to the flow path 1110a, the flow rate of the carrier gas, the flow rate of cold air supplied from the cold air supplier 52, the temperature of the cold air, the length of time the cold air is supplied, and the exhaust speed of the decompression pump 53. The plurality of control parameters may further include a time for which the valve VE is opened and / or closed, a time for which the supply of mist CLM is stopped, and a time for which the supply of cold air is stopped.

[0036] A cooling method according to one exemplary embodiment will be described below with reference to Figures 5 and 6. Figure 5 is a flow chart of the cooling method according to one exemplary embodiment. Figure 6 is a timing chart of the pressure in the flow path in the cooling method according to one exemplary embodiment. In each step of the cooling method shown in Figure 5 (hereinafter referred to as "method MT"), each part of the cooler 50 can be controlled by the control unit 2.

[0037] 5 (hereinafter referred to as "method MT") begins with step STi. In step STi, the pressure in the flow path 1110a is set to an initial pressure Pi (see FIG. 6). The initial pressure Pi is, for example, atmospheric pressure.

[0038] In the subsequent step STd, the pressure in the flow path 1110a is reduced by the decompression pump 53. As shown in Fig. 5 , in the step STd, the pressure in the flow path 1110a is reduced until it reaches a first pressure Pv. The first pressure Pv may be the minimum pressure that the decompression pump 53 can achieve. In the step STd, after the pressure in the flow path 1110a reaches the first pressure Pv, the state in which the pressure in the flow path 1110a is maintained at the first pressure Pv may continue for a specified time.

[0039] In the subsequent step STa, a mist CLM of the coolant CL is supplied from the mist generator 51 to the flow path 1110a whose pressure has been reduced by the pressure reduction pump 53. The mist CLM is supplied together with a carrier gas from the carrier gas supply unit 54. Due to the supply of the mist CLM in the step STa, the pressure in the flow path 1110a reaches a second pressure Pc. The second pressure Pc is higher than the first pressure Pv. In the step STa, after the pressure in the flow path 1110a reaches the second pressure Pc, a standby state may continue for a specified time.

[0040] In the subsequent step STb, cold air is supplied to the flow path 1110a from the cold air supplier 52. In the step STb, the cold air from the cold air supplier 52 promotes condensation of the mist CLM in the flow path 1110a (adsorption onto the surface that defines the flow path 1110a).

[0041] The method MT may further include a subsequent step STw. After the supply of cold air in step STb is stopped, a standby state continues for a specified time in step STw. In step STw, condensation of the mist CLM in the flow path 1110a (adsorption onto the surface defining the flow path 1110a) progresses.

[0042] In the subsequent process STc, the pressure in the flow path 1110a is reduced by the decompression pump 53. In the process STc, the flow path 1110a may be evacuated by the decompression pump 53. As a result, the coolant CL in the flow path 1110a evaporates, and the heat of vaporization cools the substrate support 11 (or the base 1110). In the process STc, the pressure in the flow path 1110a may be reduced until it reaches a first pressure Pv. In the process STc, after the pressure in the flow path 1110a reaches the first pressure Pv, the state in which the pressure in the flow path 1110a is maintained at the first pressure Pv may continue for a specified time. Note that the pressure in the flow path 1110a reached in the process STc may be different from the first pressure Pv.

[0043] In the method MT, a cycle including steps STa to STc may be repeated. In this case, it is determined in step STj whether a stop condition is satisfied. The stop condition is satisfied when the number of times the cycle is repeated reaches a predetermined number, or when the repetition period of the cycle reaches a predetermined length of time. If it is determined that the stop condition is not satisfied in step STj, the cycle is executed again. On the other hand, if it is determined that the stop condition is satisfied in step STj, the processing proceeds to step STv.

[0044] In the step STv, the flow path 1110a is evacuated by the decompression pump 53. In the step STv, the coolant CL in the flow path 1110a is almost completely removed. In the subsequent step STr, the pressure in the flow path 1110a is returned to the initial pressure Pi. In the step STr, air may be supplied to the flow path 1110a from the cold air supplier 52, thereby returning the pressure in the flow path 1110a to the initial pressure. In the step STr, the pressure in the flow path 1110a may be set to atmospheric pressure.

[0045] In one embodiment, the cycle including steps STa to STc may further include collecting the coolant CL using a collector 56 connected to the decompression pump 53. The cycle may also further include recovering the coolant CL using the recovery device described above.

[0046] In the method MT, as described above, each component of the cooler 50 can be controlled by the control unit 2. Each of FIGS. 7(a) to 7(d), 8(a) to 8(d), 9(a) to 9(d), and 10(a) to 10(d) is a table showing an example of the states of various valves and pumps in a cooling method according to one exemplary embodiment. These tables show the states of the valves VM, VC, VE, and RV in each step. In these tables, a circle (○) indicating a valve state indicates that the valve is open, and an cross (×) indicating a valve state indicates that the valve is closed. These tables also show the states of the pressure reduction pump 53 and the liquid circulation pump 58 in each step. In these tables, a pump state indicated as "ON" indicates that the pump is operating, and an pump state indicated as "OFF" indicates that the pump is stopped. In each step of method MT, the control unit 2 may control the states of valves VM, VC, VE, and RV, as well as the states of pressure reduction pump 53 and liquid circulation pump 58, as shown in these tables.

[0047] Reference will now be made to FIGS. 11A to 11F. Each of FIGS. 11A to 11F illustrates an example of a flow path of a base according to one exemplary embodiment. The flow path 1110a may be a single flow path extending without branching between the inlet 1110i and the outlet 1110o. Alternatively, as shown in FIGS. 11A to 11F, the flow path 1110a may include multiple branch flow paths 1110b branching from at least one inlet 1110i and joining at least one outlet. In each of the examples of FIGS. 11A to 11F, adsorption of the mist CLM onto the surface defining the flow path 1110a and desorption of the coolant CL from the surface are promoted.

[0048] In each of the examples in Figures 11(a) to 11(f), the multiple branch flow paths 1110b branch off from a single inlet 1110i and merge into a single outlet 1110o. The multiple branch flow paths 1110b extend in the circumferential direction around the central axis of the base 1110. Note that in the examples shown in Figures 11(a) and 11(c) to 11(e), the single inlet 1110i is provided in the center of the base 1110, and the single outlet 1110o is provided on the outer edge of the base 1110. However, as in the example in Figure 11(b), the single inlet 1110i may be provided on the outer edge of the base 1110, and the single outlet 1110o may be provided in the center of the base 1110. In the example of FIG. 11(f), the single inlet 1110i is provided on the outer edge of the base 1110, and the single outlet 1110o is provided on the outer edge of the base 1110 on the opposite side to the single outlet 1110o.

[0049] In the example of (g) of Figure 11, a single inlet 1110i is provided in the center of the base 1110, and multiple outlets 1110o are provided on the outer edge of the base 1110. Multiple branch flow paths 1110b branch off from the single inlet 1110i and merge at the outer edge of the base 1110, which includes multiple outlets 1110o. The multiple branch flow paths 1110b extend radially between the center of the base 1110 and the outer edge of the base 1110. Note that the single outlet 1110o may be provided in the center of the base 1110, and multiple inlets 1110i may be provided on the outer edge of the base 1110.

[0050] In the exemplary embodiment described above, the member cooled by the cooler 50 is the substrate support 11 (or its base 1110). In another exemplary embodiment, the member cooled by the cooler 50 may be a member other than the substrate support 11. Reference is now made to FIG. 12 . FIG. 12 is a diagram illustrating a modified example of a plasma processing apparatus according to one exemplary embodiment. In the plasma processing apparatus 1 illustrated in FIG. 12 , the showerhead 13 includes the upper electrode 14 described above. The upper electrode 14 provides a flow path 142f therein. The upper electrode 14 may include a top plate 141 and a support 142. The top plate 141 extends over the plasma processing space 10s so as to contact the plasma processing space 10s. The top plate 141 may be made of a conductive material such as silicon. The support 142 detachably supports the top plate 141. The support 142 may be made of a metal material such as aluminum. The support 142 may provide the flow path 142f and the gas diffusion chamber 13b. The gas inlets 13c may be formed in the support 142 and the top plate 141. In the plasma processing apparatus 1 shown in Fig. 12, the side wall 10a of the chamber 10 may have a flow path 10f formed therein.

[0051] 12, one or more coolers 50 may be connected to one or more of the flow path 10f, the flow path 142f, and the flow path 1110a. That is, in the plasma processing apparatus 1, the components cooled by the one or more coolers 50 may be one or more of the upper electrode 14 (or the support 142), the sidewall 10a of the chamber 10, and the substrate support 11 (or the base 1110).

[0052] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0053] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E13] below.

[0054] [E1] A substrate processing apparatus comprising: a member providing an interior of a flow path having an inlet and an outlet; a cooler configured to cool the member; and a control unit, wherein the cooler is configured to generate a mist of a cooling liquid, and includes: a mist generator connected to the inlet; a cold air supplier connected to the inlet; and a pressure reduction pump connected to the outlet, and the control unit is configured to control the cooler to repeatedly perform processes including: (a) supplying the mist from the mist generator to the flow path whose pressure has been reduced by the pressure reduction pump; (b) supplying cold air from the cold air supplier to the flow path; and (c) evacuating the flow path with the pressure reduction pump.

[0055] [E2] The substrate processing apparatus according to E1, further comprising: a collector connected to the outlet via the decompression pump and configured to collect the cooling liquid; and a recovery device connected between the collector and the mist generator and configured to recover and store the cooling liquid.

[0056] [E3] The substrate processing apparatus according to E2, wherein the recovery unit includes: a liquid circulation pump; a receiver having a tank for storing the cooling liquid and connected between the collector and the liquid circulation pump; and a reservoir having another tank for storing the cooling liquid and connected between the liquid circulation pump and the mist generator.

[0057] [E4] The substrate processing apparatus according to any one of E1 to E3, further comprising a carrier gas supply unit connected to the inlet via the mist generator and configured to supply a carrier gas to be supplied to the flow path together with the mist.

[0058] [E5] The substrate processing apparatus described in E4, wherein the control unit is configured to adjust one or more of a plurality of control parameters including the amount of mist generated by the mist generator, the temperature of the mist, the length of time the mist is supplied to the flow path, the flow rate of the carrier gas, the flow rate of the cold air supplied from the cold air supplier, the temperature of the cold air, the length of time the cold air is supplied, and the exhaust speed of the pressure reduction pump.

[0059] [E6] The substrate processing apparatus according to any one of E1 to E5, wherein the flow path includes a plurality of branch flow paths branching from the inlet and joining the outlet.

[0060] [E7] The substrate processing apparatus according to any one of E1 to E6, wherein the cooling liquid is water, alcohol, ammonia, or a fluorine-based liquid.

[0061] [E8] The substrate processing apparatus according to any one of E1 to E7, further comprising: a chamber; and a substrate support portion disposed in the chamber, wherein the member is the substrate support portion.

[0062] [E9] The substrate processing apparatus according to any one of E1 to E7, further comprising: a chamber; a substrate support portion disposed in the chamber; and an upper electrode provided above the substrate support portion, wherein the member is the upper electrode.

[0063] [E10] The substrate processing apparatus according to any one of E1 to E7, further comprising a chamber, wherein the member is a sidewall of the chamber.

[0064] [E11] The substrate processing apparatus according to any one of E1 to E10, wherein the substrate processing apparatus is a plasma processing apparatus.

[0065] [E12] A cooling method comprising: (a) supplying a mist of a cooling liquid from a mist generator to a flow path of a member that has been depressurized by a decompression pump; (b) supplying cold air from a cold air supplier to the flow path; (c) evacuating the flow path by the decompression pump; and (d) repeating a cycle comprising (a), (b), and (c).

[0066] [E13] The cooling method according to E12, wherein the cycle includes: collecting the cooling liquid with a collector connected to the pressure reducing pump; and recovering the cooling liquid with a collector connected between the collector and the mist generator.

[0067] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

[0068] 1...plasma processing apparatus, 10...chamber, 11...substrate support, 1110...base, 1110a...flow path, 1110i...inlet, 1110o...outlet, 50...cooler, 51...mist generator, 52...cold air supplier, 53...pressure reduction pump, 54...carrier gas supplier, 56...collector, 57...receiver, 58...liquid circulation pump, 59...reservoir.

Claims

1. A substrate processing apparatus comprising: a member providing an interior flow path having an inlet and an outlet; a cooler configured to cool the member; and a control unit, wherein the cooler is configured to generate a mist of cooling liquid and includes a mist generator connected to the inlet, a cold air supplier connected to the inlet, and a pressure reduction pump connected to the outlet, wherein the control unit is configured to control the cooler to repeatedly perform processes including: (a) supplying the mist from the mist generator to the flow path whose pressure has been reduced by the pressure reduction pump; (b) supplying cold air from the cold air supplier to the flow path; and (c) evacuating the flow path with the pressure reduction pump.

2. The substrate processing apparatus of claim 1, further comprising: a collector connected to the outlet via the pressure reducing pump and configured to collect the cooling liquid; and a recovery device configured to recover and store the cooling liquid and connected between the collector and the mist generator.

3. The substrate processing apparatus of claim 2, wherein the recovery device includes: a liquid circulation pump; a receiver having a tank for storing the cooling liquid and connected between the collector and the liquid circulation pump; and a reservoir having another tank for storing the cooling liquid and connected between the liquid circulation pump and the mist generator.

4. A substrate processing apparatus as described in any one of claims 1 to 3, further comprising a carrier gas supply unit connected to the inlet via the mist generator and configured to supply a carrier gas to be supplied to the flow path together with the mist.

5. The substrate processing apparatus of claim 4, wherein the control unit is configured to adjust one or more of a plurality of control parameters including the amount of mist generated by the mist generator, the temperature of the mist, the length of time the mist is supplied to the flow path, the flow rate of the carrier gas, the flow rate of the cold air supplied from the cold air supplier, the temperature of the cold air, the length of time the cold air is supplied, and the exhaust speed of the pressure reducing pump.

6. The substrate processing apparatus according to any one of claims 1 to 3, wherein the flow path includes a plurality of branch flow paths branching from the inlet and joining the outlet.

7. The substrate processing apparatus according to any one of claims 1 to 3, wherein the cooling liquid is water, alcohol, ammonia, or a fluorine-based liquid.

8. The substrate processing apparatus according to any one of claims 1 to 3, further comprising: a chamber; and a substrate support portion disposed within the chamber, wherein the member is the substrate support portion.

9. A substrate processing apparatus according to any one of claims 1 to 3, further comprising: a chamber; a substrate support portion disposed within the chamber; and an upper electrode provided above the substrate support portion, wherein the member is the upper electrode.

10. The substrate processing apparatus according to any one of claims 1 to 3, further comprising a chamber, and the member is a side wall of the chamber.

11. The substrate processing apparatus according to any one of claims 1 to 3, which is a plasma processing apparatus.

12. A cooling method comprising the steps of: (a) supplying a mist of cooling liquid from a mist generator to a flow path of a component that has been depressurized by a vacuum pump; (b) supplying cold air from a cold air supplier to the flow path; (c) evacuating the flow path using the vacuum pump; and (d) repeating a cycle comprising steps (a), (b), and (c).

13. The cooling method according to claim 12, wherein the cycle includes: collecting the cooling liquid with a collector connected to the pressure reducing pump; and recovering the cooling liquid with a collector connected between the collector and the mist generator.

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