Substrate processing method and substrate processing apparatus

Abstract

This substrate processing method includes steps a), b), c), and d). In step a), heat transfer gas is supplied into a space between a substrate, placed on a stage provided in a chamber, and the stage so that the pressure in the space between the substrate and the stage becomes a first pressure. In step b), the supply of the heat transfer gas into the space between the substrate and the stage is stopped, and the heat transfer gas in the space between the substrate and the stage is exhausted. In step c), the exhaust of the heat transfer gas in the space between the substrate and the stage is stopped. In step d), the heat transfer gas is supplied between the substrate and the stage so that the pressure in the space between the substrate and the stage becomes a second pressure lower than the first pressure.

Description

Substrate processing method and substrate processing apparatus

[0001] Various aspects and embodiments of the present disclosure relate to substrate processing methods and substrate processing apparatus.

[0002] Japanese Patent Application Laid-Open No. 2003-124499 discloses that "the susceptor 3 and the electrostatic chuck 6 are provided with a gas passage 9 for introducing He gas, and the gas passage 9 is connected to a He gas supply source 14 via an opening / closing valve 14 a and a flow rate control valve 14 b, and is also connected to a vacuum pump 16 via a flow rate control valve 15. The He gas is ejected onto the back surface of the wafer W through this gas passage 9, thereby making it possible to cool the wafer W placed on the susceptor 3."

[0003] Japanese Patent Application Laid-Open No. 2002-270576

[0004] The present disclosure provides a substrate processing method and a substrate processing apparatus that can quickly reduce the pressure of a heat transfer gas in a space between a substrate and a stage to a target pressure.

[0005] A substrate processing method according to one aspect of the present disclosure includes steps a), b), c), and d). In step a), a heat transfer gas is supplied into a space between a substrate placed on a stage provided in a chamber and the stage so that the pressure in the space between the substrate and the stage becomes a first pressure. In step b), the supply of the heat transfer gas into the space between the substrate and the stage is stopped, and the heat transfer gas in the space between the substrate and the stage is exhausted. In step c), the exhaust of the heat transfer gas in the space between the substrate and the stage is stopped. In step d), a heat transfer gas is supplied between the substrate and the stage so that the pressure in the space between the substrate and the stage becomes a second pressure lower than the first pressure.

[0006] According to various aspects and embodiments of the present disclosure, the pressure of the heat transfer gas in the space between the substrate and the stage can be quickly reduced to a target pressure.

[0007] FIG. 1 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus. FIG. 2 is a schematic diagram illustrating an example of a process for changing the pressure of a heat transfer gas in a heat transfer space between a substrate and an electrostatic chuck in a reference example. FIG. 3 is a schematic diagram illustrating an example of a process for changing the pressure of a heat transfer gas in a heat transfer space between a substrate and an electrostatic chuck in a reference example. FIG. 4 is a schematic diagram illustrating an example of a process for changing the pressure of a heat transfer gas in a heat transfer space between a substrate and an electrostatic chuck in this embodiment. FIG. 5 is a schematic diagram illustrating an example of a process for changing the pressure of a heat transfer gas in a heat transfer space between a substrate and an electrostatic chuck in this embodiment. FIG. 6 is a schematic diagram illustrating an example of a process for changing the pressure of a heat transfer gas in a heat transfer space between a substrate and an electrostatic chuck in this embodiment. FIG. 7 is a diagram illustrating an example of a process for changing the pressure in the heat transfer space. FIG. 8 is a flowchart illustrating an example of a substrate processing method. FIG. 9 is a diagram illustrating another example of the configuration of a capacitively coupled plasma processing apparatus.

[0008] Hereinafter, embodiments of a substrate processing method and a substrate processing apparatus will be described in detail with reference to the drawings. However, the substrate processing method and the substrate processing apparatus disclosed below are not limited to the following embodiments.

[0009] The pressure of the heat transfer gas supplied into the space between the substrate and the stage supporting the substrate may be changed depending on the substrate temperature to be set. The pressure in the space between the substrate and the stage supporting the substrate (hereinafter referred to as the heat transfer space) is often measured by a pressure gauge installed in a pipe (hereinafter referred to as the supply pipe) connecting the heat transfer space to a heat transfer gas supply source.

[0010] Here, the conductance of the supply pipe is often smaller than the conductance of the heat transfer space. Therefore, when the pressure in the heat transfer space is reduced from a first pressure to a second pressure, even if the pressure gauge detects that the pressure in the supply pipe has reached the second pressure, the pressure in the heat transfer space may still be higher than the second pressure. In this case, after the pressure gauge detects that the pressure in the supply pipe has reached the second pressure, the pressure gauge may again detect that the pressure in the supply pipe has reached a pressure higher than the second pressure.

[0011] Therefore, when the pressure in the heat transfer space is reduced from the first pressure to the second pressure, it may take a long time for the pressure in the heat transfer space to stabilize at the second pressure, which may result in a longer processing time when processing substrates at different temperatures.

[0012] Therefore, the present disclosure provides a technique that can quickly reduce the pressure of the heat transfer gas in the space between the substrate and the stage to a target pressure.

[0013] [Configuration of Plasma Processing System] An example of the configuration of a plasma processing system will be described below: Fig. 1 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus.

[0014] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a controller 2. The capacitively coupled plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 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 to 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.

[0015] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 is an example of a stage. 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.

[0016] 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. Alternatively, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0017] 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.

[0018] The substrate support 11 may also include a temperature regulation module configured to regulate at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate W to a target temperature. The temperature regulation 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 within the ceramic member 1111a of the electrostatic chuck 1111.

[0019] The substrate support 11 is also provided with a pipe 11a communicating with the space between the substrate W and the central region 111a. A heat transfer gas supply unit 50, which is a supply source of heat transfer gas such as helium gas, is connected to the pipe 11a via a PCV (pressure control valve) 51. The pipe 11a is an example of a first pipe. The heat transfer gas supplied from the heat transfer gas supply unit 50 is supplied to the space between the substrate W and the central region 111a via the PCV 51 and the pipe 11a. The PCV 51 measures the pressure of the heat transfer gas in the pipe 11a and controls the amount of heat transfer gas supplied from the heat transfer gas supply unit 50 to the pipe 11a so that the pressure in the pipe 11a becomes a set pressure. Thus, the pressure of the heat transfer gas supplied to the space between the substrate W and the central region 111a is controlled by the PCV 51. An exhaust system 40 is connected to the pipe 11a via a pipe 11b. An exhaust valve 52 is provided to the pipe 11b. The heat transfer gas supply unit 50 and the PCV 51 are an example of a heat transfer gas supply mechanism. The pipe 11b and the exhaust valve 52 are an example of an exhaust mechanism. The PCV 51 is an example of a pressure gauge, and the pipe 11b is an example of a second pipe.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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. The 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).

[0029] 2 and 3 are schematic diagrams showing an example of a process for changing the pressure of the heat transfer gas in the heat transfer space 1111c between the substrate W and the electrostatic chuck 1111 in a reference example. In FIGS. 2 and 3, a case is described in which the pressure in the heat transfer space 1111c is changed from a first pressure P1 to a second pressure P2 lower than the first pressure P1. The first pressure P1 is, for example, 45 torr (approximately 6000 Pa), and the second pressure P2 is, for example, 15 torr (approximately 2000 Pa). In FIGS. 2 and 3, regions corresponding to high-pressure spaces are darkly hatched, and regions corresponding to low-pressure spaces are lightly hatched.

[0030] When the pressure in the heat transfer space 1111c is changed from the first pressure P1 to the second pressure P2, in the reference example, the exhaust valve 52 is opened while the pressure of the heat transfer gas in the heat transfer space 1111c is controlled to the first pressure P1, for example, as shown in Fig. 2. Then, when the PCV 51 detects that the pressure in the pipe 11a has dropped to the second pressure P2, the exhaust valve 52 is closed.

[0031] However, because the conductance of the pipe 11a is small, when the PCV 51 detects that the pressure in the pipe 11a has dropped to the second pressure, the pressure in the heat transfer space 1111c may not have dropped to the second pressure P2, as shown in Fig. 3. In this case, after the exhaust valve 52 is closed, the PCV 51 detects that the pressure in the pipe 11a has exceeded the second pressure P2, and the exhaust valve 52 is opened again.

[0032] Depending on the magnitude of the conductance of the pipe 11a, the exhaust valve 52 may be repeatedly opened and closed until the pressure in the pipe 11a stabilizes at the second pressure P2, which may take some time until the pressure in the heat transfer space 1111c stabilizes at the second pressure P2.

[0033] 4 to 6 are schematic diagrams showing an example of a process for changing the pressure of the heat transfer gas in the heat transfer space 1111c between the substrate W and the electrostatic chuck 1111 in this embodiment. Also in Fig. 4 to Fig. 6, a case where the pressure in the heat transfer space 1111c is changed from a first pressure P1 to a second pressure P2 is described. Also in Fig. 4 to Fig. 6, regions corresponding to spaces with high pressure are darkly hatched, and regions corresponding to spaces with low pressure are lightly hatched.

[0034] 4, the exhaust valve 52 is opened while the pressure in the heat transfer space 1111c is controlled to a first pressure P1. The exhaust valve 52 is kept open until the pressure in the pipe 11a is maintained by the PCV 51 at or below a third pressure P3, which is lower than the second pressure P2, for a predetermined period of time or longer.

[0035] 4 to 6, the conductance of the pipe 11b is greater than the conductance of the pipe 11a, so that when the exhaust valve 52 is opened, the heat transfer gas in the heat transfer space 1111c can be more quickly exhausted through the pipe 11a.

[0036] After the PCV 51 detects that the pressure in the pipe 11a is equal to or lower than the third pressure P3 for a predetermined time or longer, the exhaust valve 52 is closed. The predetermined time is, for example, 2 seconds. The third pressure P3 is, for example, 2 torr (approximately 267 Pa).

[0037] As a result, the pressure in the pipe 11a becomes equal to or lower than the third pressure P3, as shown in Fig. 5. The pressure in the heat transfer space 1111c becomes lower than at least the second pressure P2.

[0038] Then, the heat transfer gas is supplied into the heat transfer space 1111c through the pipe 11a, and the pressure in the pipe 11a is adjusted to the second pressure P2 by the PCV 51. As a result, the pressure in the heat transfer space 1111c can be quickly stabilized at the second pressure P2, as shown in Fig. 6, for example.

[0039] [Time Required for Pressure in Heat Transfer Space 1111c to Stabilize] Fig. 7 is a diagram showing an example of the process of change in pressure in the heat transfer space 1111c. In the example of Fig. 7, the change in pressure in the heat transfer space 1111c in the reference example is shown by a dashed line, and the change in pressure in the heat transfer space 1111c in this embodiment is shown by a solid line.

[0040] In the reference example, the exhaust valve 52 is opened at timing t1 when the pressure in the heat transfer space 1111c is at a first pressure P1. Then, the exhaust valve 52 is repeatedly opened and closed, and the pressure in the heat transfer space 1111c gradually approaches a second pressure P2. Then, at timing t3, the pressure in the heat transfer space 1111c stabilizes at the second pressure P2.

[0041] In contrast, in this embodiment, when the pressure in the heat transfer space 1111c is at the first pressure P1, the exhaust valve 52 is opened at timing t1. After the time Δt during which the pressure in the pipe 11a is equal to or lower than the third pressure continues for a predetermined time or longer, the exhaust valve 52 is closed and the heat transfer gas is supplied into the electrostatic chuck 11111c. As a result, although there is a slight overshoot, the pressure in the heat transfer space 1111c quickly reaches the second pressure P2 and stabilizes at timing t2, which is earlier than timing t3.

[0042] Thus, according to the heat transfer gas pressure control method of this embodiment, the pressure in the heat transfer space 1111c between the substrate W and the electrostatic chuck 1111 can be quickly reduced from the first pressure P1 to the second pressure P2.

[0043] 8 is a flowchart showing an example of a substrate processing method, which is realized by the control unit 2 controlling each part of the plasma processing apparatus 1.

[0044] First, a gate valve (not shown) provided on the sidewall 10a of the plasma processing chamber 10 is opened, and a substrate W is loaded into the plasma processing chamber 10. The substrate W is then placed on the electrostatic chuck 1111, and the gate valve is closed. Power is then supplied to the electrostatic electrode 1111b of the electrostatic chuck 1111, and the substrate W is attracted and held to the electrostatic chuck 1111 by electrostatic force. A heat transfer gas is then supplied into the heat transfer space 1111c between the substrate W and the electrostatic chuck 1111. The control unit 2 then controls the PCV 51 to adjust the pressure of the heat transfer gas supplied into the heat transfer space 1111c so that the pressure measured by the PCV 51 becomes a first pressure P1 (step S10). Step S10 is an example of step a).

[0045] Next, the control unit 2 controls each part of the plasma processing apparatus 1 to perform a first process on the substrate W (step S11). The first process is performed while the substrate W is controlled to a first temperature.

[0046] Next, the control unit 2 controls the PCV 51 to stop the supply of heat transfer gas to the heat transfer space 1111c (step S12). Then, the control unit 2 controls the exhaust valve 52 to open, thereby exhausting the heat transfer gas from the heat transfer space 1111c through the pipes 11a and 11b (step S13). Steps S12 and S13 are an example of process b).

[0047] Next, the control unit 2 determines whether the pressure measured by the PCV 51 is equal to or lower than the third pressure P3 (step S14). If the pressure measured by the PCV 51 is higher than the third pressure P3 (step S14: No), the process shown in step S14 is executed again.

[0048] On the other hand, if the measured pressure value becomes equal to or less than the third pressure P3 (step S14: Yes), the control unit 2 determines whether the measured pressure value equal to or less than the third pressure P3 has continued for a predetermined time or more (step S15). If the measured pressure value equal to or less than the third pressure P3 has not continued for a predetermined time or more (step S15: No), the process shown in step S15 is executed again.

[0049] On the other hand, if the measured pressure is equal to or less than the third pressure P3 for a predetermined time or longer (step S15: Yes), the control unit 2 closes the exhaust valve 52 to stop exhausting the heat transfer gas from the heat transfer space 1111c (step S16). Then, the control unit 2 controls the PCV 51 to resume supplying the heat transfer gas into the heat transfer space 1111c via the pipe 11a (step S17). Step S16 is an example of process c).

[0050] Next, the control unit 2 determines whether the pressure measured by the PCV 51 has reached the second pressure P2 (step S18). If the pressure measurement has not reached the second pressure P2 (step S18: No), the process shown in step S18 is executed again.

[0051] On the other hand, if the measured pressure reaches the second pressure P2 (step S18: Yes), the control unit 2 controls each part of the plasma processing apparatus 1 to perform a second process on the substrate W (step S19). The second process is a process performed while the substrate W is controlled to a second temperature different from the first temperature. Steps S17 and S18 are an example of process d). Then, the substrate processing method shown in this flowchart ends.

[0052] The embodiment has been described above. As described above, the substrate processing method in this embodiment includes steps a), b), c), and d). In step a), a heat transfer gas is supplied into a space between a substrate (substrate W) placed on a stage (main body 111) provided in a chamber (plasma processing chamber 10) and the stage (heat transfer space 1111c) so that the pressure in the space between the substrate and the stage becomes a first pressure. In step b), the supply of heat transfer gas into the space between the substrate and the stage is stopped, and the heat transfer gas in the space between the substrate and the stage is exhausted. In step c), the exhaust of heat transfer gas in the space between the substrate and the stage is stopped. In step d), a heat transfer gas is supplied between the substrate and the stage so that the pressure in the space between the substrate and the stage becomes a second pressure lower than the first pressure. This allows the pressure of the heat transfer gas in the space between the substrate and the stage to be quickly reduced to a target pressure.

[0053] In the above embodiment, in step b), the heat transfer gas in the space between the substrate and the stage is exhausted by opening an exhaust valve (exhaust valve 52) provided on a second pipe (pipe 11b), one end of which is connected to a first pipe (pipe 11a) that connects the space between the substrate and the stage to a heat transfer gas supply unit (heat transfer gas supply unit 50) that is a supply source of heat transfer gas, and the other end of which is connected to an exhaust system (exhaust system 40) that exhausts gas in the chamber. This makes it possible to easily exhaust the heat transfer gas in the space between the substrate and the stage.

[0054] In the above embodiment, the conductance of the second pipe is greater than the conductance of the first pipe, which allows the heat transfer gas in the space between the substrate and the stage to be exhausted more quickly.

[0055] In the above-described embodiment, the pressure in the space between the substrate and the stage is measured by a pressure gauge provided in the first pipe, thereby making it possible to measure the pressure in the space between the substrate and the stage.

[0056] In the above-described embodiment, in step b), the heat transfer gas in the space between the substrate and the stage is exhausted until the pressure in the space between the substrate and the stage becomes equal to or lower than a third pressure that is lower than the second pressure, thereby enabling the pressure in the space between the substrate and the stage to be reduced quickly.

[0057] In the above-described embodiment, in step b), the heat transfer gas in the space between the substrate and the stage continues to be exhausted until the pressure in the space between the substrate and the stage remains equal to or lower than the third pressure for a predetermined period of time or more, thereby sufficiently reducing the pressure in the space between the substrate and the stage.

[0058] In the above-described embodiment, the heat transfer gas is, for example, helium gas, which allows the heat transfer rate between the substrate and the stage to be controlled by controlling the pressure in the space between the substrate and the stage.

[0059] The above-described embodiment is a substrate processing apparatus (plasma processing apparatus 1) including a chamber (plasma processing chamber 10), a stage (main body 111), a heat transfer gas supply mechanism (heat transfer gas supply unit 50, PCV 51), an exhaust mechanism (piping 11b, exhaust valve 52), and a control unit (control unit 2). The stage is provided within the chamber and supports a substrate W. The heat transfer gas supply mechanism supplies heat transfer gas into a space (heat transfer space 1111c) between the stage and a substrate placed on the stage. The exhaust mechanism exhausts the heat transfer gas from the space between the substrate and the stage. The control unit executes steps a), b), c), and d). In step a), the heat transfer gas supply unit is controlled to supply heat transfer gas into the space between the substrate and the stage so that the pressure in the space between the substrate and the stage becomes a first pressure. In step b), the heat transfer gas supply unit is controlled to stop the supply of heat transfer gas into the space between the substrate and the stage, and the exhaust mechanism is controlled to exhaust the heat transfer gas in the space between the substrate and the stage. In step c), the exhaust mechanism is controlled to stop the exhaust of the heat transfer gas in the space between the substrate and the stage. In step d), the heat transfer gas supply mechanism is controlled to supply heat transfer gas between the substrate and the stage so that the pressure in the space between the substrate and the stage becomes a second pressure lower than the first pressure. This allows the pressure of the heat transfer gas in the space between the substrate and the stage to be quickly reduced to the target pressure.

[0060] [Others] The technology disclosed in the present application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0061] For example, in the above-described embodiment, the pipe 11b is provided between the pipe 11a and the exhaust system 40, but the disclosed technology is not limited to this. As another embodiment, for example, as shown in Fig. 9, one end of the pipe 11b may communicate with the heat transfer space 1111c between the substrate W and the electrostatic chuck 1111, and the other end of the pipe 11b may communicate with the space inside the plasma processing chamber 10. In this case, it is preferable that the opening of the other end of the pipe 11b be provided near the gas exhaust port 10e, for example, as shown in Fig. 9. This makes it possible to prevent the substrate W from being affected by the heat transfer gas exhausted through the pipe 11b.

[0062] 9, it is also necessary to open the exhaust valve 52 provided in the pipe 11b to reduce the pressure in the heat transfer space 1111c between the substrate W and the electrostatic chuck 1111 to the third pressure or less. Therefore, the pressure in the plasma processing chamber 10 is lower than the first pressure P1, the second pressure P2, and the third pressure P3.

[0063] Furthermore, in the above-described embodiment, a plasma processing apparatus 1 that processes a substrate W using plasma was used as an example, but the disclosed technology can also be applied to other processing apparatuses that do not use plasma, as long as they are apparatuses that process substrates W.

[0064] In the above embodiment, the plasma processing apparatus 1 is described as performing processing using a capacitively coupled plasma (CCP) as an example of a plasma source, but the plasma source is not limited to this. Examples of plasma sources other than the capacitively coupled plasma include inductively coupled plasma (ICP), microwave-excited surface wave plasma (SWP), electron cyclotron resonance plasma (ECP), and helicon wave-excited plasma (HWP).

[0065] It should be noted that the disclosed embodiments are illustrative in all respects and should not be considered limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0066] Furthermore, the following supplementary notes are disclosed regarding the above-described embodiment.

[0067] (Supplementary Note 1) A substrate processing method comprising the steps of: a) supplying a heat transfer gas into a space between a substrate placed on a stage provided in a chamber and the stage so that the pressure in the space between the substrate and the stage becomes a first pressure, b) stopping the supply of the heat transfer gas into the space and exhausting the heat transfer gas from the space, c) stopping the exhaust of the heat transfer gas from the space, and d) supplying the heat transfer gas into the space so that the pressure in the space becomes a second pressure lower than the first pressure. (Supplementary Note 2) The substrate processing method according to Supplementary Note 1, wherein in step b), the heat transfer gas in the space is exhausted by opening an exhaust valve provided on a second pipe, the second pipe having one end connected to a first pipe connecting the space to a heat transfer gas supply unit that is a supply source of the heat transfer gas, and the other end connected to an exhaust system that exhausts gas in the chamber. (Supplementary Note 3) The substrate processing method according to Supplementary Note 2, wherein the conductance of the second pipe is greater than the conductance of the first pipe. (Supplementary Note 4) The substrate processing method according to Supplementary Note 2 or 3, wherein the pressure in the space is measured by a pressure gauge provided in the first pipe. (Supplementary Note 5) The substrate processing method according to any one of Supplements 1 to 4, wherein in step b), the heat transfer gas in the space is exhausted until the pressure in the space becomes equal to or less than a third pressure that is lower than the second pressure. (Supplementary Note 6) The substrate processing method according to Supplementary Note 5, wherein in step b), the heat transfer gas in the space is continued to be exhausted until the pressure in the space remains lower than the third pressure for a predetermined time or more. (Supplementary Note 7) The substrate processing method according to Supplementary Note 1, wherein in step b), the heat transfer gas in the space is exhausted by opening an exhaust valve provided in a second pipe having one end connected to the space and the other end connected to a space in the chamber. (Supplementary Note 8) The substrate processing method according to Supplementary Note 7, wherein the first pressure and the second pressure are higher than a pressure in the chamber when processing the substrate on the stage. (Supplementary Note 9) The substrate processing method according to any one of Supplementary Notes 1 to 8, wherein the heat transfer gas is helium gas.(Supplementary Note 10) A substrate processing apparatus comprising: a chamber; a stage provided in the chamber and supporting a substrate; a heat transfer gas supply mechanism that supplies a heat transfer gas into a space between the stage and the substrate placed on the stage; an exhaust mechanism that exhausts the heat transfer gas from the space; and a control unit, wherein the control unit performs the following steps: a) controlling the heat transfer gas supply mechanism to supply the heat transfer gas into the space so that the pressure in the space becomes a first pressure; b) controlling the heat transfer gas supply mechanism to stop the supply of the heat transfer gas into the space and controlling the exhaust mechanism to exhaust the heat transfer gas from the space; c) controlling the exhaust mechanism to stop the exhaust of the heat transfer gas from the space; and d) controlling the heat transfer gas supply mechanism to supply the heat transfer gas into the space so that the pressure in the space becomes a second pressure lower than the first pressure.

[0068] REFERENCE SIGNS LIST W substrate 1 plasma processing apparatus 10 plasma processing chamber 10a side wall 10e gas exhaust port 10s plasma processing space 11 substrate support 11a piping 11b piping 111 main body 111a central region 111b annular region 1110 base 1110a flow path 1111 electrostatic chuck 1111a ceramic member 1111b electrostatic electrode 1111c heat transfer space 112 ring assembly 13 shower head 13a gas supply port 13b gas diffusion chamber 13c gas inlet 20 gas supply unit 21 gas source 22 flow rate controller 30 power supply 31 RF power supply 31a first RF generation unit 31b second RF generation unit 32 DC power supply 32a first DC generation unit 32b Second DC generating unit 40 Exhaust system 2 Control unit 2a Computer 2a1 Processing unit 2a2 Storage unit 2a3 Communication interface 50 Heat transfer gas supply unit 51 PCV 52 Exhaust valve

Claims

1. A substrate processing method comprising: a) a step of supplying a heat transfer gas into a space between a substrate placed on a stage provided in a chamber and the stage so that the pressure in the space between the substrate and the stage becomes a first pressure; b) a step of stopping the supply of the heat transfer gas into the space and exhausting the heat transfer gas from the space; c) a step of stopping the exhaust of the heat transfer gas from the space; and d) a step of supplying the heat transfer gas into the space so that the pressure in the space becomes a second pressure lower than the first pressure.

2. A substrate processing method as described in claim 1, wherein in step b), the heat transfer gas in the space is exhausted by opening an exhaust valve provided on a second pipe, the second pipe having one end connected to a first pipe connecting the space to a heat transfer gas supply unit that is a supply source of the heat transfer gas and the other end connected to an exhaust system that exhausts gas in the chamber.

3. The substrate processing method according to claim 2, wherein the conductance of the second pipe is greater than the conductance of the first pipe.

4. A substrate processing method according to claim 2 or 3, wherein the pressure in the space is measured by a pressure gauge provided in the first pipe.

5. A substrate processing method according to claim 1, wherein in step b), the heat transfer gas in the space is exhausted until the pressure in the space becomes equal to or lower than a third pressure lower than the second pressure.

6. A substrate processing method according to claim 5, wherein in step b), the heat transfer gas in the space continues to be exhausted until the pressure in the space remains below the third pressure for a predetermined period of time or more.

7. A substrate processing method as described in claim 1, wherein in step b), the heat transfer gas in the space is exhausted by opening an exhaust valve provided on a second pipe having one end connected to the space and the other end connected to the space within the chamber.

8. The substrate processing method according to claim 7, wherein the first pressure and the second pressure are higher than the pressure in the chamber when the substrate is processed.

9. The substrate processing method according to claim 1, wherein the heat transfer gas is helium gas.

10. A substrate processing apparatus comprising: a chamber; a stage provided within the chamber and supporting a substrate; a heat transfer gas supply mechanism configured to supply a heat transfer gas into a space between the stage and the substrate placed on the stage; an exhaust mechanism configured to exhaust the heat transfer gas from the space; and a control unit, wherein the control unit is configured to perform the following steps: a) controlling the heat transfer gas supply mechanism to supply the heat transfer gas into the space so that the pressure in the space becomes a first pressure; b) controlling the heat transfer gas supply mechanism to stop the supply of the heat transfer gas into the space and controlling the exhaust mechanism to exhaust the heat transfer gas from the space; c) controlling the exhaust mechanism to stop the exhaust of the heat transfer gas from the space; and d) controlling the heat transfer gas supply mechanism to supply the heat transfer gas into the space so that the pressure in the space becomes a second pressure lower than the first pressure.

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