Gas supply system, gas control system, plasma processing device, and gas control method

Abstract

This gas supply system for supplying gas to the inside of a processing chamber comprises: a plurality of gas supply flow paths configured to be able to supply gas independently to the processing chamber; a flow rate controller disposed on each of the gas supply flow paths; a primary-side valve disposed on the upstream side of the flow rate controller in the gas supply flow paths; a primary-side gas exhaust flow path that branches off between the primary-side valve and the flow rate controller in the gas supply flow paths and is connected to a primary-side exhaust mechanism; a primary-side exhaust valve disposed in the primary gas exhaust flow path; a secondary-side valve disposed on the downstream side of the flow rate controller in the gas supply flow paths; a secondary-side gas exhaust flow path that branches off between the secondary-side valve and the flow rate controller in the gas supply flow paths and is connected to a secondary-side exhaust mechanism; and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path. The flow rate controller has a control valve connected to the primary-side valve and the secondary-side valve, and a control-side orifice disposed between the control valve and the secondary-side valve.

Description

Gas supply system, gas control system, plasma processing apparatus, and gas control method

[0001] The present disclosure relates to a gas supply system, a gas control system, a plasma processing apparatus, and a gas control method.

[0002] Patent Document 1 discloses a gas supply control method using a pressure-controlled flow meter provided in a gas supply line, a first valve provided in the gas supply line upstream of the pressure-controlled flow meter, and a second valve provided in the gas supply line downstream of the pressure-controlled flow meter. The pressure-controlled flow meter described in Patent Document 1 includes, for example, a control valve connected to the first valve and the second valve, and an orifice provided between the control valve and the second valve.

[0003] Japanese Patent Application Laid-Open No. 2016-201530

[0004] The technology according to the present disclosure appropriately exhausts gas from inside a flow rate controller that controls the flow rate of gas supplied into a processing chamber.

[0005] One aspect of the present disclosure is a gas supply system for supplying gas into a processing chamber, the system comprising: a plurality of gas supply flow paths configured to be able to supply gas independently to the processing chamber; a flow rate controller disposed in each of the plurality of gas supply flow paths; a primary-side valve disposed upstream of the flow rate controller in the gas supply flow path; a primary-side gas exhaust flow path branching between the flow rate controller and the primary-side valve in the gas supply flow path and connected to a primary-side exhaust mechanism; a primary-side exhaust valve disposed in the primary-side gas exhaust flow path; a secondary-side valve disposed downstream of the flow rate controller in the gas supply flow path; a secondary-side gas exhaust flow path branching between the flow rate controller and the secondary-side valve in the gas supply flow path and connected to a secondary-side exhaust mechanism; and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path, wherein the flow rate controller comprises a control valve connected to the primary-side valve and the secondary-side valve, and a control-side orifice disposed between the control valve and the secondary-side valve.

[0006] According to the present disclosure, gas can be appropriately exhausted from inside a flow rate controller that controls the flow rate of gas supplied into a processing chamber.

[0007] 1 is a graph showing the occurrence of a spike at the start of processing; FIG. 2 is a graph showing the deterioration of gas fall at the end of processing; FIG. 3 is an explanatory diagram showing an example of the configuration of a wafer processing system according to an embodiment; FIG. 4 is a cross-sectional view showing an example of the configuration of a plasma processing apparatus according to an embodiment; FIG. 5 is a system diagram showing an example of the configuration of a gas supply unit according to an embodiment; FIG. 6 is an explanatory diagram showing another example of the configuration of a gas supply unit; FIG. 7 is an explanatory diagram showing another example of the configuration of a gas supply unit; FIG. 8 is an explanatory diagram showing a schematic view of the inside of a flow rate controller in wafer processing according to an embodiment; FIG. 9 is a graph showing the pressure inside a flow rate controller in wafer processing according to an embodiment; FIG. 10 is an explanatory diagram showing the operation timing of various members in wafer processing according to an embodiment; FIG. 11 is an explanatory diagram showing the inside of a flow rate controller in wafer processing according to another embodiment; FIG. 12 is a graph showing the inside of a chamber at the start of processing according to an embodiment; FIG. 13 is a graph showing the relationship between evacuation time in a flow rate controller and internal pressure; FIG. 14 is a graph showing the relationship between evacuation time in a flow rate controller and internal pressure of a plasma processing chamber; FIG. 15 is an explanatory diagram showing the operation timing of various members in substrate processing according to a second embodiment; FIG. 16 is an explanatory diagram showing a schematic view of the inside of a flow rate controller in substrate processing according to the second embodiment; 10 is a graph showing the effect of a control method according to a second embodiment of the present invention; FIG. 11 is a diagram showing a schematic diagram of the inside of a flow rate controller in substrate processing according to another embodiment; FIG. 12 is a diagram showing another configuration example of a gas supply unit; FIG. 13 is a diagram showing a graph showing the effect of a control method according to a second embodiment of the present invention;

[0008] In the manufacturing process of semiconductor devices, various gas processes such as etching, film formation, and cleaning are performed on semiconductor substrates (hereinafter referred to as "wafers") placed in the internal space of a chamber under desired gas atmospheres. In these gas processes, it is important to precisely control the flow rate of gas supplied to the internal space of the chamber in order to obtain the desired gas processing results for the wafers being processed.

[0009] Patent Document 1 discloses a gas supply control method using a pressure-controlled flow meter that controls the flow rate of gas supplied to the internal space of a chamber. According to the gas supply control method described in Patent Document 1, for example, by controlling the opening and closing of a first valve and a second valve provided respectively upstream and downstream of the pressure-controlled flow meter, the supply and stopping of gas to the internal space of the chamber is repeated, thereby alternately performing an etching process and a deposition process on a wafer.

[0010] Between the etching process and the deposition process, i.e., while the supply of gas to the internal space of the chamber is stopped, the gas supply passage (pressure-controlled flow meter) is evacuated to ensure an appropriate supply of gas to the internal space of the chamber in the next process. The gas supply passage is evacuated using, for example, a vacuum line (see Patent Document 1: Type 1) connected between an orifice of the pressure-controlled flow meter and the first valve, or an exhaust line (Type 2) connected downstream of the chamber.

[0011] However, when a pressure-controlled flow meter includes an orifice as described above, conventional vacuum pumping methods (Type 1 and Type 2) may not be able to properly evacuate the supply flow path, which may affect the wafer processing. Specifically, for example, when exhausting from the upstream side of the orifice as in the above-described Type 1, gas may remain in the supply flow path downstream of the orifice, which may cause a spike S at the start of the next process, as shown in Fig. 1. Furthermore, when exhausting from the downstream side of the orifice as in the above-described Type 2, gas may remain upstream of the orifice, which may cause a deterioration in the fall response when the gas supply is stopped, as shown in Fig. 2.

[0012] The technology disclosed herein has been developed in consideration of the above circumstances, and provides a method for appropriately exhausting gas from inside a flow rate controller that controls the flow rate of gas supplied into a processing chamber. Hereinafter, a wafer processing system including a gas supply system (gas control system) and a plasma processing apparatus according to this embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0013] <Plasma Processing System> In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2, as shown in FIG. 3 . 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 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.

[0014] The plasma generating unit 12 is configured to generate plasma from at least one 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 generating units may be used, including alternating current (AC) plasma generating units and direct current (DC) plasma generating units. 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. Therefore, AC signals include RF (Radio Frequency) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0015] The controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The controller 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 controller 2 may be included in the plasma processing apparatus 1. The controller 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 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 storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), a SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network). The program may be recorded on a storage medium readable by the computer 2a and installed into the control unit 2 from the storage medium. The storage medium may be temporary or non-temporary.

[0016] <Plasma Processing Apparatus> Next, a configuration example of a capacitively coupled plasma processing apparatus 1 will be described as an example of the above-mentioned plasma processing apparatus 1. FIG.

[0017] 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 substrate support 11 is disposed within the plasma processing chamber 10. The gas inlet is configured to introduce at least one gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. 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. Within the plasma processing chamber 10, a plasma processing space 10s is 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 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 isolated from the plasma processing chamber 10 .

[0018] The substrate support 11 includes a main body 11a and a ring assembly 11b. The top surface of the main body 11a has a central region for supporting a substrate W and an annular region for supporting the ring assembly 11b. A wafer is an example of a substrate W. The annular region surrounds the central region in a plan view. The substrate W is disposed on the central region, and the ring assembly 11b is disposed on the annular region so as to surround the substrate W on the central region. Therefore, the central region is also called a substrate support surface for supporting the substrate W, and the annular region is also called a ring support surface for supporting the ring assembly 11b.

[0019] In one embodiment, the main body 11a includes a base and an electrostatic chuck. The base includes a conductive member. The conductive member of the base can function as a lower electrode. The electrostatic chuck is disposed on the base. The electrostatic chuck includes a ceramic member and an electrostatic electrode disposed within the ceramic member. The ceramic member has a central region. In one embodiment, the ceramic member also has an annular region. Note that another member surrounding the electrostatic chuck, such as the annular electrostatic chuck or an annular insulating member, may also have the annular region. In this case, the ring assembly 11b may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck and the annular insulating member. An RF or DC electrode may also be disposed within the ceramic member, in which case the RF or DC electrode functions as a lower electrode. When a bias RF signal or DC signal, described below, is connected to the RF or DC electrode, the RF or DC electrode is also referred to as a bias electrode. Note that both the conductive member of the base and the RF or DC electrode may function as a lower electrode.

[0020] The ring assembly 11b 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.

[0021] Although not shown, the substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the ring assembly 11b, the electrostatic chuck, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. In one embodiment, the flow path is formed in the base, and one or more heaters are disposed in a ceramic member of the electrostatic chuck. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas (backside gas) between the back surface of the substrate W and a central region.

[0022] The shower head 13 is configured to introduce at least one gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 includes a conductive member. The conductive member of the shower head 13 functions as an upper electrode. That is, the shower head 13 includes an upper electrode.

[0023] The shower head 13 has at least one gas supply port 14c, 14m, and 14e (three in this embodiment), at least one gas diffusion chamber 15c, 15m, and 15e (three in this embodiment), and a plurality of gas inlets 16. Gas supplied from the gas supply unit 20 to the gas supply port 14c passes through the gas diffusion chamber 15c and is supplied from the plurality of gas inlets 16 toward a center region of the substrate W supported on the substrate support 11. Gas supplied from the gas supply unit 20 to the gas supply port 14e passes through the gas diffusion chamber 15e and is supplied from the plurality of gas inlets 16 toward a peripheral region of the substrate W supported on the substrate support 11. Gas supplied from the gas supply unit 20 to the gas supply port 14m passes through the gas diffusion chamber 15m and is supplied from the plurality of gas inlets 16 toward a middle region between the center region and the peripheral region of the substrate W supported on the substrate support 11.

[0024] In addition to the shower head 13, the gas introduction part may include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0025] FIG. 5 is a system diagram showing a piping system of a gas supply unit 20 as a gas supply system. In the following description, the side of a gas source 100 (described later) in the gas flow direction may be referred to as the primary side (upstream side), and the side of a shower head 13 in the gas flow direction may be referred to as the secondary side (downstream side). In FIG. 4 , to avoid cluttering the illustration, only one flow control unit 110 is shown among the multiple flow control units 110a to 110e (described later) shown in FIG. 5 , and the numerals a to e are omitted. In other words, the flow control unit 110 shown in FIG. 4 represents any one of the flow control units 110a to 110e. Similarly, in FIG. 4 , the various components arranged corresponding to the respective flow control units 110a to 110e have the same configuration, and therefore the numerals a to e are omitted. In other words, the various components shown in FIG. 4 are arranged corresponding to at least one of the flow control units 110a to 110e. Similarly, in the following description, the numbers a to e of the flow control units 110a to 110e and the various components arranged correspondingly may be omitted.

[0026] 5, the gas supply unit 20 includes at least one gas source 100a-100e (five in this embodiment) and at least one flow rate control unit 110a-110e (five in this embodiment) corresponding to each of the gas sources 100a-100e. In one embodiment, the gas supply unit 20 is configured to supply different types of gases output from the five gas sources 100 to the showerhead 13 via the corresponding flow rate control units 110.

[0027] 4 and 5 , each flow rate control unit 110 is connected to a corresponding gas source 100 via a primary supply pipe 120 serving as a corresponding gas supply flow path. A corresponding primary valve 121 is disposed in each primary supply pipe 120, and the gas supply from the gas source 100 to each flow rate control unit 110 can be arbitrarily switched by opening and closing the primary valve 121. Note that any type of valve, such as an air-operated valve or an electromagnetic valve, can be used as the primary valve 121, but from the viewpoint of improving responsiveness in gas supply, it is preferable to use, for example, an electromagnetic valve.

[0028] Furthermore, an exhaust unit 131 is connected to the primary-side supply pipe 120 between the primary-side valve 121 and the flow rate control unit 110, i.e., downstream of the primary-side valve 121 and upstream of the flow rate control unit 110, via a primary-side exhaust pipe 130. In one example, the exhaust unit 131 as a primary-side exhaust mechanism is provided in common to each flow rate control unit 110. Furthermore, a primary-side exhaust valve 132 corresponding to each flow rate control unit 110 is disposed in the primary-side exhaust pipe 130 as a primary-side gas exhaust flow path. By opening and closing the primary-side exhaust valve 132, the inside of the flow rate control unit 110 and the primary-side supply pipe 120 can be evacuated. The exhaust unit 131 may include a vacuum pump. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof. The exhaust unit 131 may be used in common with an exhaust system 40 (described later) connected to the plasma processing chamber 10 and an exhaust unit 151 (described later). Furthermore, any type of valve can be used as the primary side exhaust valve 132, such as an air-operated valve or an electromagnetic valve, but from the viewpoint of improving the response to gas exhaust, it is preferable to use, for example, an electromagnetic valve.

[0029] Each flow rate control unit 110 includes three pressure-controlled flow rate controllers 111c, 111m, and 111e (hereinafter, these may be collectively referred to simply as "flow rate controllers 111") for controlling the flow rates of gases supplied to the three gas supply ports 14c, 14m, and 14e of the showerhead 13. The three flow rate controllers 111 are connected to ends of branched primary-side supply pipes 120 (branched supply pipes). In one example, the primary-side supply pipe 120 branches into three branched supply pipes downstream of a connection point between the primary-side supply pipe 120 and the primary-side exhaust pipe 130.

[0030] The configuration of the flow rate controller 111 will be described using Fig. 4. Since the configurations of the flow rate controllers 111c, 111m, and 111e are the same, in Fig. 4, the numbers of elements having the same functional configuration may be omitted in order to prevent the illustration from becoming complicated.

[0031] The flow rate controller 111 includes an internal supply pipe 112, an orifice 113, two pressure sensors 114 and 115, a control valve 116, and a control circuit 117. The internal supply pipe 112, which serves as a gas supply flow path, includes a primary internal supply pipe 112a on the upstream side and a secondary internal supply pipe 112b on the downstream side, with the orifice 113 as the boundary.

[0032] The primary side of the primary-side internal supply pipe 112a is connected to the above-mentioned primary-side supply pipe 120, and the secondary side is connected to the orifice 113. The primary side of the secondary-side internal supply pipe 112b is connected to the orifice 113, and the secondary side is connected to the below-described secondary-side supply pipe 140. In other words, the orifice 113 is provided between the primary-side internal supply pipe 112a and the secondary-side internal supply pipe 112b.

[0033] The two pressure sensors 114, 115 measure the internal pressures of the primary-side internal supply pipe 112a and the secondary-side internal supply pipe 112b, respectively, i.e., the pressures upstream and downstream of the orifice 113. Hereinafter, the internal pressure of the primary-side internal supply pipe 112a measured by the pressure sensor 114 may be referred to as "internal pressure P1," and the internal pressure of the secondary-side internal supply pipe 112b measured by the pressure sensor 115 may be referred to as "internal pressure P2."

[0034] The opening of the control valve 116 is controlled by the control circuit 117, thereby controlling the flow rate of gas flowing through the internal supply pipe 112 and supplied into the plasma processing chamber 10 (shower head 13). More specifically, the control circuit 117 controls the opening of the control valve 116 to adjust the internal pressure P1 of the primary internal supply pipe 112a, thereby controlling the flow rate of gas flowing downstream of the orifice 113 (secondary internal supply pipe 112b) to be maintained at a desired value determined depending on the purpose of wafer processing in the plasma processing chamber 10.

[0035] Additionally, the control valve 116 may function as a flow rate modulation device that modulates or pulses the flow rate of at least one gas under the control of the control circuit 117 .

[0036] Returning to the description of the gas supply unit 20, as shown in FIGS. 4 and 5 , each of the flow rate controllers 111c, 111m, and 111e is connected to one of the gas supply ports 14c, 14m, and 14e of the corresponding shower head 13 via a corresponding secondary-side supply pipe 140c, 140m, or 140e serving as a gas supply flow path. A corresponding secondary-side valve 141 is disposed in each secondary-side supply pipe 140, and the gas supply from each flow rate controller 111 to the shower head 13 can be arbitrarily switched by opening or closing the secondary-side valve 141. Any type of valve, such as an air-operated valve or an electromagnetic valve, can be used as the secondary-side valve 141. However, from the viewpoint of improving responsiveness in gas supply, it is preferable to use, for example, an electromagnetic valve. In the plasma processing apparatus 1 according to this embodiment, other valves (for example, the primary side valve 121, the primary side exhaust valve 132, or the secondary side exhaust valve 152 described below) can also be made into electromagnetic valves, but by making the secondary side valve 141 into an electromagnetic valve in this manner, the responsiveness to gas supply can be particularly suitably improved.

[0037] Furthermore, the secondary-side supply pipes 140 join downstream of the corresponding secondary-side valves 141 and are then connected to the shower head 13. This allows different types of gases to be mixed as desired and supplied to the shower head 13 as a mixed gas by switching the gas supply from each flow rate controller 111 by opening and closing the secondary-side valves 141.

[0038] Furthermore, an exhaust unit 151 is connected to the secondary-side supply pipe 140 between the flow rate controller 111 and the secondary-side valve 141, i.e., upstream of the secondary-side valve 141 and downstream of the flow rate controller 111, via a secondary-side exhaust pipe 150. In one example, the exhaust unit 151 as a secondary-side exhaust mechanism is provided in common to each flow rate controller 111. Furthermore, a secondary-side exhaust valve 152 corresponding to each flow rate controller 111 is disposed in the secondary-side exhaust pipe 150 as a secondary-side gas exhaust flow path. By opening and closing the secondary-side exhaust valve 152, the inside of the flow rate controller 111 (flow rate control unit 110) and the secondary-side supply pipe 140 can be evacuated. The exhaust unit 151 may include a vacuum pump. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof. The exhaust unit 151 may be used in common with the exhaust system 40 and exhaust unit 131 (described later) connected to the plasma processing chamber 10. Furthermore, any type of valve, such as an air-operated valve or an electromagnetic valve, can be used as the secondary-side exhaust valve 152, but from the viewpoint of improving the responsiveness of gas exhaust, it is preferable to use, for example, an electromagnetic valve.

[0039] In one embodiment, the secondary-side supply pipes 140 may be connected to other gas supply units 160 downstream of the corresponding secondary-side valves 141. In other words, the gas supplied from the gas supply unit 20 to the shower head 13 via the flow rate control units 110 may be further mixed with other gases supplied from other gas supply units 160.

[0040] The other gas supply unit 160 may include at least one gas source 161 and at least one flow controller 162. In one embodiment, the gas supply unit 160 is configured to supply at least one gas from a corresponding gas source 161 to the showerhead 13 via a corresponding flow controller 162. Each flow controller 162 may include, for example, a mass flow controller or a pressure-controlled flow controller.

[0041] In one embodiment, the other gas supply unit 160 may be configured to be able to supply a larger flow rate of gas to the shower head 13 than the gas supply unit 20. In other words, the gas supply unit 20 may be configured to be able to supply a small flow rate of gas (e.g., 0.1 to 10 sccm, preferably 0.5 to 2 sccm) to the shower head 13.

[0042] In one embodiment, the operation of the gas supply unit 20 is controlled by the aforementioned control unit 2. Specifically, for example, the control unit 2 is configured to be able to independently control the apertures of various valves (primary-side valve 121, primary-side exhaust valve 132, secondary-side valve 141, and secondary-side exhaust valve 152) included in the gas supply unit 20. As a result, the gas supply unit 20 independently controls the gas supply from each of the multiple flow rate control units 110 to the plasma processing chamber 10, and also independently controls the exhaust from inside the supply pipes of each of the multiple flow rate control units 110.

[0043] Returning to the description of the plasma processing apparatus 1 in FIG. 4 , 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), such as a source RF signal and a bias RF signal, to a conductive member (lower electrode) of the substrate support 11 and / or a conductive member (upper electrode) of the showerhead 13. This causes plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0044] 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 the lower electrode and / or the 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 the lower electrode and / or the upper electrode.

[0045] The second RF generator 31b is coupled to the 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 the lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0046] 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 lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal may be applied to another electrode, such as a chucking electrode in an electrostatic chuck. In one embodiment, the second DC generator 32b is connected to the upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the upper electrode.

[0047] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of DC-based voltage pulses is applied to the lower electrode and / or the upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof. 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 the 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 the 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.

[0048] 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 regulating valve regulates the internal pressure of the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0049] 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.

[0050] For example, in the above embodiment, the gas supply unit 20 is provided with five flow rate control units 110a to 110e corresponding to the five gas sources 100a to 100e, respectively. In other words, the gas supply unit 20 has a single system configuration in which one type of gas is supplied to each flow rate control unit 110. However, the configuration of the gas supply unit 20 is not limited to this, and may have two or more systems in which multiple types of gas (two types in the example of FIG. 6) are supplied to each flow rate control unit 110, as shown in FIG. 6 .

[0051] In the above embodiment, in the gas supply unit 20, as shown in FIG. 4 , various components (primary-side valve 121, primary-side exhaust valve 132, orifice 113, secondary-side exhaust valve 152, and secondary-side valve 141) are independently connected to various supply pipes (primary-side supply pipe 120, internal supply pipe 112, and secondary-side supply pipe 140). However, the configuration of the gas supply unit 20 is not limited to this. From the viewpoint of improving maintainability of the gas supply unit 20, it is desirable that various components are integrally connected to the various supply pipes. Specifically, as shown as an example in the schematic diagram of FIG. 7 , the various components (primary-side valve 121, primary-side exhaust valve 132, orifice 113, secondary-side exhaust valve 152, and secondary-side valve 141) connected to the various supply pipes may be integrally configured by being fixed to a mounting plate 170 as a mounting member.

[0052] <Wafer Processing Method (First Embodiment)> Next, a wafer processing method as a gas supply method (gas control method) according to a first embodiment performed using the wafer processing system configured as described above will be described. Note that the following description will be given taking as an example a case where an etching process (ALE: Atomic Layer Etching) is performed on a substrate W to be processed in the plasma processing chamber 10, but the type of gas processing performed on the substrate W is not limited to the following example. For example, in the plasma processing chamber 10, any gas processing such as a film formation process or a cleaning process may be performed instead of an etching process.

[0053] In this embodiment, three types of gases, for example, a CF-based gas (e.g., C ４ F ６ , C ４ F ８ etc.), oxygen (O ２ An example will be described in which a substrate W is etched using a CF-based gas supplied from the gas source 100a and argon (Ar) gas supplied from the gas source 100c. The supply flow rate of the CF-based gas supplied from the gas source 100a is controlled by the flow rate control unit 110a. The supply flow rate of the oxygen gas supplied from the gas source 100b is controlled by the flow rate control unit 110b. The supply flow rate of the argon gas supplied from the gas source 100c is controlled by the flow rate control unit 110c.

[0054] FIG. 8 is an explanatory diagram showing the operation of the flow rate controller 111 in the main steps of wafer processing. FIG. 9 is a graph showing the measured values ​​of the pressure sensors 114 and 115, i.e., the internal pressures of the primary-side internal supply pipe 112a and the secondary-side internal supply pipe 112b, in the main steps shown in FIG. 8 . FIG. 10 is a timing chart showing wafer processing according to one embodiment. In FIG. 8 , the three flow rate controllers 111c, 111m, and 111e included in the flow rate control unit 110 are all illustrated as the flow rate controller 111. In other words, the flow rate controller 111 shown in FIG. 8 refers to any one of the flow rate controllers 111c, 111m, and 111e. The operation of these flow rate controllers 111c, 111m, and 111e is similar.

[0055] When starting the etching process on the substrate W in the plasma processing chamber 10, first, the primary valve 121c and the secondary valve 141c of the flow rate control unit 110c are opened to start the supply of Ar gas to the plasma processing chamber 10 (step St0 in FIG. 10 ). The Ar gas acts as a carrier gas in the etching process, and is continuously supplied throughout the etching process.

[0056] The flow rates of Ar gas supplied into the plasma processing chamber 10 to the gas supply ports 14c, 14m, and 14e of the shower head 13 are individually controlled by three flow rate controllers 111c, 111m, and 111e of the flow rate control unit 110c. The Ar gas supplied into the plasma processing chamber 10 may be supplied from another gas supply unit 160. In one example, the supply flow rate of argon gas supplied into the plasma processing chamber 10 is greater than the supply flow rates of the CF-based gas supplied from the gas source 100a and the oxygen gas supplied from the gas source 100b.

[0057] Next, as shown in FIG. 8A, the primary valve 121a and secondary valve 141a of the flow rate control unit 110a are opened to start supplying the CF-based gas into the plasma processing chamber 10 (step St1 in FIGS. 9 and 10). In step St1, the gas introduced from the gas source 100a to the flow rate controller 111 is supplied to the plasma processing chamber 10 after its flow rate is reduced by the orifice 113. In other words, the internal pressure of the secondary internal supply pipe 112b is lower than the internal pressure of the primary internal supply pipe 112a. In step St1, the CF-based gas supplied into the plasma processing chamber 10 forms a CF-based deposit on the substrate W (hereinafter, this may be referred to as the "deposition step").

[0058] The CF-based gas supplied into the plasma processing chamber 10 is controlled by three flow rate controllers 111c, 111m, and 111e of the flow rate control unit 110a, with the flow rates thereof individually controlled for the gas supply ports 14c, 14m, and 14e of the shower head 13. In other words, the supply flow rates of the CF-based gas to the center region, middle region, and edge region of the substrate W are individually controlled, thereby controlling the amount of CF-based deposits formed in each of these center region, middle region, and edge region.

[0059] 8B, the primary-side valve 121a and the secondary-side valve 141a of the flow rate control unit 110a are closed to stop the supply of the CF-based gas into the plasma processing chamber 10 (step St2 in FIGS. 9 and 10). In step St2, the primary-side valve 121a and the secondary-side valve 141a are closed, thereby isolating the inside of the flow rate controller 111, the primary-side supply pipe 120, and the secondary-side supply pipe 140 from the outside. As a result, the gas in the primary-side supply pipe 120 moves into the secondary-side supply pipe 140 through the orifice, and the internal pressures of the primary-side supply pipe 120 and the secondary-side supply pipe 140 approximately match and reach an equilibrium state.

[0060] 8(c), the primary-side exhaust valve 132a and secondary-side exhaust valve 152a of the flow control unit 110a are opened to evacuate the inside of the flow control unit 110a (flow rate controller 111) that has supplied the CF-based gas (step St3 in FIGS. 9 and 10: hereinafter, sometimes referred to as the "first evacuation step"). More specifically, by opening the primary-side exhaust valve 132a, the exhaust unit 131 evacuates the inside of the primary-side supply pipe 120 and the primary-side internal supply pipe 112a, and by opening the secondary-side exhaust valve 152a, the exhaust unit 151 evacuates the inside of the secondary-side supply pipe 140 and the secondary-side internal supply pipe 112b. In order to appropriately suppress the occurrence of spike S shown in FIG. 1, it is desirable that the exhaust unit 151 exhaust the flow control unit 110a (flow controller 111) until, for example, the pressure inside the flow control unit 110a becomes less than the internal pressure during flow control (during the deposition process), preferably until the gas inside the flow control unit 110a is completely exhausted.

[0061] In this embodiment, the inside of the flow rate controller 111 is evacuated using the exhaust unit 131 and the exhaust unit 151 connected respectively to the upstream and downstream sides of the flow rate controller 111. As a result, even when the flow rate controller 111 includes the orifice 113, the time required to evacuate the primary-side internal supply pipe 112a upstream of the orifice 113 and the secondary-side internal supply pipe 112b downstream of the orifice 113 can be appropriately shortened, and gas can be appropriately prevented from remaining in the primary-side internal supply pipe 112a and the secondary-side internal supply pipe 112b.

[0062] Next, as shown in Figure 8(d), the control valve 116, primary-side exhaust valve 132a, and secondary-side exhaust valve 152a of the flow control unit 110a are closed, and exhaust from the flow control unit 110a is stopped (step St4 in Figures 9 and 10). In step St4, the primary-side valve 121a and secondary-side valve 141a are closed, thereby isolating the inside of the flow controller 111, primary-side supply pipe 120, and secondary-side supply pipe 140 from the outside. As a result, gas in the primary-side supply pipe 120 moves into the secondary-side supply pipe 140 through the orifice, and the internal pressures of the primary-side supply pipe 120 and secondary-side supply pipe 140 approximately match and reach an equilibrium state.

[0063] After the first exhaust process (step St4) is completed, it may be confirmed that the residual gas in the flow controller 111a has been properly exhausted by opening the control valve 116 of the flow controller 111a and the secondary valve 141a of the flow control unit 110a as shown in FIG. 8(e) (step St5 in FIGS. 9 and 10).

[0064] In the following description, steps St1 to St5 may be collectively referred to as the "deposition process (first process)," in other words, the deposition process and the first exhaust process.

[0065] Next, the primary valve 121b and the secondary valve 141b of the flow rate control unit 110b are opened to allow O 2 to flow into the plasma processing chamber 10. ２The supply of gas is started (see FIG. 8( a)). At the same time, the supply of an RF signal (RF power) from the RF power supply 31 to the conductive member (lower electrode) of the substrate support 11 and / or the conductive member (upper electrode) of the shower head 13 is started (step St6 in FIGS. 9 and 10). In step St6, the gas introduced from the gas source 100b to the flow rate controller 111 is supplied to the plasma processing chamber 10 after its flow rate is reduced by the orifice 113. In other words, the internal pressure of the secondary-side internal supply pipe 112b is lower than the internal pressure of the primary-side internal supply pipe 112a. In step St6, the O 2 supplied into the plasma processing chamber 10 is ２ A plasma derived from the gas is generated and the substrate W is etched (hereinafter, this may be referred to as the "etching step").

[0066] In addition, O supplied into the plasma processing chamber 10 ２ The flow rates of the gases supplied to the gas supply ports 14c, 14m, and 14e of the shower head 13 are individually controlled by three flow rate controllers 111c, 111m, and 111e of the flow rate control unit 110b. In other words, the O 2 gases supplied to the center region, middle region, and edge region of the substrate W are individually controlled by three flow rate controllers 111c, 111m, and 111e of the flow rate control unit 110b. ２ By individually controlling the gas supply flow rates, the etching amount of the substrate W in the center region, middle region, and edge region is individually controlled.

[0067] After etching of the substrate W is completed, the primary valve 121b and the secondary valve 141b of the flow rate control unit 110b are closed to stop the flow of O 2 into the plasma processing chamber 10. ２ The supply of gas is stopped (step St7 in FIGS. 9 and 10: see FIG. 8(b)). In step St7, the primary-side valve 121b and the secondary-side valve 141b are closed, thereby isolating the inside of the flow rate controller 111, the primary-side supply pipe 120, and the secondary-side supply pipe 140 from the outside. As a result, the gas in the primary-side supply pipe 120 moves into the secondary-side supply pipe 140 through the orifice, and the internal pressures of the primary-side supply pipe 120 and the secondary-side supply pipe 140 approximately match and reach an equilibrium state.

[0068] Next, the primary side exhaust valve 132b and the secondary side exhaust valve 152b of the flow rate control unit 110b are opened (see FIG. 8(c)). ２ The inside of the flow control unit 110b (flow controller 111) that has supplied the gas is evacuated (step St8 in FIGS. 9 and 10 ; hereinafter, this may be referred to as the “second evacuation step”). More specifically, the primary-side exhaust valve 132b is opened to evacuate the inside of the primary-side supply pipe 120 and the primary-side internal supply pipe 112a by the exhaust unit 131, and the secondary-side exhaust valve 152a is opened to evacuate the inside of the secondary-side supply pipe 140 and the secondary-side internal supply pipe 112b by the exhaust unit 151. Note that the detailed evacuation method for the flow control unit 110b is the same as the evacuation method for the flow control unit 110a in step St3. In order to appropriately suppress the occurrence of spike S shown in FIG. 1, it is desirable that the exhaust unit 151 exhaust the gas from the flow control unit 110b (flow controller 111) until the pressure inside the flow control unit 110b becomes less than the internal pressure during flow control (during the etching process), preferably until the gas inside the flow control unit 110b is completely exhausted.

[0069] Next, the control valve 116, the primary-side exhaust valve 132b, and the secondary-side exhaust valve 152b of the flow rate control unit 110b are closed, and the exhaust of the flow rate control unit 110b is stopped (see step St9 in FIGS. 9 and 10: FIG. 8(d)). In step St9, the primary-side valve 121b and the secondary-side valve 141b are closed, thereby isolating the inside of the flow rate controller 111, the primary-side supply pipe 120, and the secondary-side supply pipe 140 from the outside. As a result, the gas in the primary-side supply pipe 120 moves into the secondary-side supply pipe 140 through the orifice, and the internal pressures of the primary-side supply pipe 120 and the secondary-side supply pipe 140 approximately match and reach an equilibrium state.

[0070] After the second exhaust process (step St9) is completed, the control valve 116 of the flow controller 111a and the secondary valve 141a of the flow control unit 110a may be opened (see FIG. 8(e)) to confirm that the residual gas in the flow controller 111a has been properly exhausted (step St10 in FIGS. 9 and 10).

[0071] In the following description, steps St6 to St10, in other words the etching process and the second exhaust process, may be collectively referred to as the "etching process (second process)."

[0072] In this embodiment, a process cycle including the first process (steps St1 to St5) as a deposition process and the second process (steps St6 to St10) as an etching process is repeatedly executed until a desired etching amount is obtained for the substrate W, as shown in Fig. 10. In one example, the time required for one cycle is, for example, 1 to 10 seconds, preferably 0.5 to 3 seconds for the deposition process and 0.5 to 7 seconds for the etching process, and more preferably 1 to 2 seconds for the deposition process and 3 to 5 seconds for the etching process.

[0073] Thereafter, when the cycle is repeated one or more times as desired, it is determined whether a further etching process cycle (deposition process (first process) and etching process (second process)) is necessary, and if it is determined that a further etching process cycle is necessary, the process returns to step St1 as shown in Figure 10, and the first process and the second process are repeated. If it is determined that a further etching process cycle is not necessary, the etching process for the substrate W is terminated.

[0074] If it is determined that another etching process cycle is necessary, the flow rates of the CF-based gas and O 2 are again supplied from the flow rate control units 110a and 110b to the plasma processing chamber 10, as shown in FIG. ２ At this time, it is necessary to restart the gas supply from gas sources 100a and 100b. However, if the gas supply is started while the inside of flow control unit 110 is in a vacuum state as shown in FIG. 8D, it is necessary to fill flow control unit 110 with gas before starting the gas supply to plasma processing chamber 10, which increases the time required to restart the process.

[0075] Therefore, in the plasma processing according to this embodiment, when the etching process cycle is repeated as described above, and particularly when the gas supply unit 20 has a single system configuration in which one type of gas is supplied to one flow rate control unit 110, a pre-control preparation may be performed prior to resuming the gas supply to the plasma processing chamber 10. Specifically, as shown in FIG. 11E, the primary valve 121 of the flow rate control unit 110 is opened to fill the primary supply pipe 120 with gas, and the secondary valve 141 is opened to balance the internal pressure of the internal supply pipe 112 and the secondary supply pipe 140 with the internal pressure of the plasma processing chamber 10. This shortens the time required to fill the gas from the gas source 100 when the process is resumed, and also suppresses a sudden inflow of gas into the plasma processing chamber 10, thereby more appropriately suppressing the occurrence of the spike S shown in FIG. 1 .

[0076] The steps shown in (a) to (d) of Fig. 11 are the same as the steps shown in (a) to (d) of Fig. 8. In this case, the steps of confirming that the residual gas in the flow rate controller 111a has been properly exhausted (steps St5 and St10) corresponding to Fig. 8(e) may be omitted as shown in Fig. 11, or, although not shown, the primary side valve 121 and the secondary side valve 141 may be opened after the confirmation steps (steps St5 and St10).

[0077] 12 is a graph showing the results of a comparison for examining the effects of the plasma processing apparatus 1 according to the above embodiment, and shows the results of a comparison with a case (Type 1 shown in FIG. 1) in which exhaust was performed using only the exhaust unit 131 connected upstream of the orifice 113. In both the comparative example (Type 1) and the example shown in FIG. 12, a vacuum was drawn to the flow rate controller 111 for a short period of time (for example, about 1 second).

[0078] 12 , if exhaust is performed using only the exhaust unit 131 connected upstream of the orifice 113, there is a concern that a spike S will occur due to gas remaining in the secondary-side internal supply pipe 112b when the secondary-side valve 141 is subsequently opened. The concern about the occurrence of such a spike S becomes greater particularly when the evacuation time of the flow rate controller 111 is short. In this regard, in the present embodiment, it has been found that by performing exhaust using the exhaust unit 151 connected downstream of the orifice 113 as well, the occurrence of the spike S can be suppressed even when the evacuation time of the flow rate controller 111 is short (approximately 1 sec in this embodiment).

[0079] FIG. 13 is a graph showing the relationship between the evacuation time and the internal pressure of the flow rate controller 111 in the first evacuation step (step St3) and the second evacuation step (step St9). Here, in order to appropriately suppress the occurrence of spike S when the process is restarted, it is necessary to lower the internal pressure of the flow rate controller 111 during evacuation compared to the pressure during flow rate control (process). In this regard, as shown in FIG. 13 , the inventors have found that by providing an exhaust line between the orifice 113 of the flow rate controller 111 and the secondary valve 141 as described above, the internal pressure of the flow rate controller 111 can be reduced to a pressure lower than the pressure during flow rate control, even when the evacuation time is set to 2 seconds or less, more specifically, 0.5 seconds. That is, the inventors have found that the time required for evacuation in the first evacuation step (step St3) and the second evacuation step (step St9) can be reduced to 0.5 seconds or less.

[0080] As described above, in the plasma processing apparatus 1 according to this embodiment, an exhaust line (secondary-side exhaust pipe 150, exhaust unit 151, and secondary-side exhaust valve 152) is provided between the orifice 113 of the flow rate controller 111 and the secondary-side valve 141 in the gas supply unit 20 that supplies gas into the plasma processing chamber 10. This allows the inside of the flow rate controller 111 to be evacuated in a short time between processes in the plasma processing (between the deposition step and the etching step in the above embodiment), thereby appropriately suppressing the occurrence of spikes S when the process is restarted.

[0081] 11( e), prior to resuming gas supply to the plasma processing chamber 10, gas is filled into the primary supply pipe 120 as a pre-control preparation, and the internal pressures of the internal supply pipe 112, the secondary supply pipe 140, and the plasma processing chamber 10 are equilibrated. This makes it possible to appropriately shorten the time required to fill the flow rate controller 111 with gas when the process is resumed, and further appropriately suppress the occurrence of a spike S when the process is resumed.

[0082] In the above embodiment, the flow control unit 110 (flow rate controller 111) was evacuated until the pressure inside the flow control unit 110 became lower than the internal pressure during flow control (during the deposition process or the etching process), preferably until the gas inside the flow control unit 110b was completely exhausted. However, the ultimate pressure after evacuating the flow control unit 110 (flow rate controller 111) is not limited to this.

[0083] Specifically, as described above, particularly when the gas supply unit 20 has a single-system configuration that supplies one type of gas to one flow control unit 110, mixing of multiple types of gas is suppressed inside the flow control unit 110. For this reason, when the flow control unit 110 (flow rate controller 111) is configured with a single system in this way, the gas inside the flow control unit 110 may not be completely exhausted during evacuation, and some of it may remain.

[0084] As described above, the occurrence of the spike S when the process is restarted can be appropriately suppressed by setting the pressure inside the flow rate control unit 110 below the internal pressure during flow rate control. Meanwhile, particularly in the etching process of a substrate W, it is important to shorten the plasma start-up time inside the plasma processing chamber (increasing the slope of the graph shown in FIG. 1 ). The inventors have found that the plasma start-up time can be shortened by flowing gas remaining in the flow rate control unit 110 (flow rate controller 111) into the plasma processing chamber 10 when the process is restarted. In other words, the inventors have found that the etching process of a substrate W can be more efficiently performed by evacuating the flow rate control unit 110 (flow rate controller 111) to a pressure that suppresses the occurrence of the spike S when the process is restarted and shortens the plasma start-up time.

[0085] After careful investigation, the present inventors discovered that by setting the internal pressure of the flow control unit 110 (flow controller 111) after evacuation to, for example, 100 Torr or less, preferably 50 Torr or less, it is possible to suppress the occurrence of spikes S when the process is restarted and to suitably shorten the plasma start-up time.

[0086] Furthermore, the technology disclosed herein can properly exhaust the inside of the flow rate controller 111 even when the evacuation time is shortened in this manner, and is therefore particularly suitable for use when the gas supply unit 20 has a configuration of two or more systems (see Figure 6).

[0087] Specifically, when the gas supply unit 20 has a configuration of two or more systems, that is, when two or more types of gases are supplied to one flow rate controller 111, it is necessary to prevent different types of gases from mixing inside the flow rate controller 111. In other words, before switching the supply of one gas to the flow rate controller 111 to the supply of another gas, it is necessary to sufficiently exhaust one gas as a residual gas from inside the flow rate controller 111.

[0088] In this regard, the inventors have found that, in a conventional exhaust method (e.g., Type 1 shown in FIG. 1 ), it takes about 60 seconds of evacuation to exhaust residual gas from flow controller 111 to a degree that can suppress the effects of residual gas in plasma processing chamber 10, as shown in FIG. 14 . However, according to this embodiment, the effects of residual gas can be sufficiently suppressed even with evacuation of about 2 seconds. That is, while it was conventionally necessary to exhaust one gas for about 60 seconds to suppress mixing of one gas with another gas inside flow controller 111, the inventors have found that by further performing evacuation downstream of orifice 113, the evacuation time of the one gas can be shortened to about 2 seconds. In other words, the inventors have found that the fall response of evacuation of flow controller 111 can be improved.

[0089] As described above, according to this embodiment, particularly when the gas supply unit 20 has a configuration of two or more systems, it is possible to instantly switch the gas supply from different gas sources 100 to one flow rate controller 111.

[0090] <Wafer Processing Method (Second Embodiment)> As described above, in the etching process of a substrate W, it is important to shorten the plasma start-up time inside the plasma processing chamber (hereinafter referred to as "improving the start-up response"). However, as shown in the above embodiment, when the flow rate controller 111 is evacuated (first exhaust step and second exhaust step) to resume the process, if the secondary valve 141 is opened while there is a difference in internal pressure between the internal supply pipe 112 and the secondary supply pipe 140, an inflow of Ar gas from the secondary supply pipe 140 to the internal supply pipe 112 may occur, causing a delay in the supply of the CF-based gas from the flow rate controller 111 to the plasma processing chamber 10 and deteriorating the start-up response of the etching process. As described above, the supply flow rate of the argon gas supplied into the plasma processing chamber 10 is set to be higher than the supply flow rates of the CF-based gas supplied from the gas source 100a and the oxygen gas supplied from the gas source 100b. Therefore, the internal pressure of the secondary supply pipe 140, which is the destination of the secondary valve 141 opening, rises, and this deterioration in the start-up response is of particular concern.

[0091] Therefore, in the plasma processing according to the technology of the present disclosure, in order to suppress such deterioration of the rise response, the flow rate controller 111 may be filled with gas and the internal supply pipe 112 may be pressurized (hereinafter referred to as a "pre-charge process") prior to supplying a CF-based gas or the like to the plasma processing chamber 10. A wafer processing method according to a second embodiment, including this pre-charge process, will be described below with reference to the drawings. Note that in the following description, detailed description of operations (steps) that are substantially the same as those in the above embodiment will be omitted.

[0092] FIG. 15 is a timing chart of substrate processing according to one embodiment. FIG. 16 is an explanatory diagram showing the operation of the flow rate controller 111 in the main steps of wafer processing. In FIG. 16, the three flow rate controllers 111c, 111m, and 111e included in the flow rate control unit 110 are collectively referred to as the flow rate controller 111. That is, the flow rate controller 111 shown in FIG. 16 includes the flow rate controllers 111c, 111m, and 111e. Similarly, the primary-side valve 121, primary-side exhaust valve 132, secondary-side valve 141, and secondary-side exhaust valve 152 shown in FIG. 16 include the primary-side valves 121a and 121b, primary-side exhaust valves 132a and 132b, and secondary-side valves 141a and 141b corresponding to the gas sources 100a and 100b, respectively.

[0093] 16( a), before starting the etching process on the substrate W in the plasma processing chamber 10, the primary side valve 121, the primary side exhaust valve 132, the control valve 116, the secondary side valve 141, and the secondary side exhaust valve 152 are all closed to stop the gas supply to the plasma processing chamber 10. In addition, the inside of the flow rate controller 111 is evacuated.

[0094] When starting the etching process on the substrate W in the plasma processing chamber 10, first, the supply of Ar gas from the other gas supply unit 160 to the plasma processing chamber 10 is started (step Sp0 in FIG. 15 ). The Ar gas acts as a carrier gas in the etching process and is continuously supplied throughout the etching process. Note that the Ar gas supplied into the plasma processing chamber 10 may be supplied from the gas source 100c instead of the other gas supply unit 160, as in the above embodiment.

[0095] 16B, only the primary valve 121a and the control valve 116 of the flow control unit 110a are opened (the secondary valve 141a is not opened), and the filling of the flow controller 111 of the flow control unit 110a with the CF-based gas begins (step Sp1 in FIG. 15). In step Sp1, prior to the supply of the CF-based gas to the plasma processing chamber 10, the flow controller 111 is filled with the CF-based gas, and the internal supply pipe 112 is pressurized (first precharge process).

[0096] Here, the internal pressure inside the secondary-side supply pipe 140, which is the destination of the opening of the secondary-side valve 141a, rises with the supply of Ar gas to the plasma processing chamber 10 in step Sp0. As a result, if the secondary-side valve 141a is opened while there is a difference in internal pressure between the internal supply pipe 112 and the secondary-side supply pipe 140, for example, an inflow of Ar gas from the secondary-side supply pipe 140 to the internal supply pipe 112 occurs, causing a delay in the supply of the CF-based gas from the flow rate controller 111 to the plasma processing chamber 10, which may deteriorate the startup response of the etching process.

[0097] Therefore, in this embodiment, the flow rate controller 111 is filled with the CF-based gas prior to supplying the CF-based gas, and the internal pressure of the internal supply pipe 112 (more specifically, the internal pressure P2 of the secondary-side internal supply pipe 112b) is increased. This reduces the difference in internal pressure between the internal supply pipe 112 and the secondary-side supply pipe 140, and suppresses deterioration in the start-up response of the etching process.

[0098] It is desirable to increase the internal pressure of the internal supply pipe 112 to a level that is approximately equal to the internal pressure of the secondary supply pipe 140. Specifically, it is desirable to increase the internal pressure to approximately 80 to 120% of the internal pressure of the secondary supply pipe 140. If the internal pressure of the internal supply pipe 112 is less than 80% of the internal pressure of the secondary supply pipe 140, the start-up response of the etching process may deteriorate, as described above. Furthermore, if the internal pressure of the internal supply pipe 112 exceeds 120% of the internal pressure of the secondary supply pipe 140, the CF-based gas may suddenly flow from the internal supply pipe 112 into the plasma processing chamber 10, which may cause the spike S described above.

[0099] It is desirable that the CF-based gas be filled into the flow rate controller 111 at a flow rate that is at least smaller than the flow rate of the CF-based gas supplied in the deposition step (step Sp2) described below. More specifically, as shown in Fig. 15, it is desirable that the opening of the control valve 116 when the CF-based gas is filled into the flow rate controller 111 be controlled to be smaller than the opening of the control valve 116 in the deposition step (step Sp2).

[0100] When the pressure inside the internal supply pipe 112 is increased to the desired pressure, the secondary valve 141a is then opened as shown in FIG. 16(c) to supply the CF-based gas into the plasma processing chamber 10, i.e., the deposition process described above is started (step Sp2 in FIG. 15).

[0101] Once the CF-based deposits have been formed on the substrate W, the primary side valve 121a, the control valve 116, and the secondary side valve 141a of the flow control unit 110a are then closed as shown in FIG. 16(d), and the supply of the CF-based gas into the plasma processing chamber 10 is stopped (step Sp3 in FIG. 15).

[0102] Next, as shown in FIG. 16( e), the primary-side exhaust valve 132 a and the secondary-side exhaust valve 152 a of the flow control unit 110 a are opened, and the inside of the flow control unit 110 a (flow controller 111) that has supplied the CF-based gas is evacuated (first exhaust step: step Sp4 in FIG. 15 ).

[0103] Next, as shown in Fig. 16(f), the primary-side exhaust valve 132a and the secondary-side exhaust valve 152a are closed to stop the exhaust of the flow rate control unit 110a (step Sp5 in Fig. 15). After the first exhaust step (step Sp4) is completed, the control valve 116 of the flow rate controller 111a and the secondary-side valve 141a of the flow rate control unit 110a may be opened to confirm that the residual gas in the flow rate controller 111a has been properly exhausted.

[0104] In the above description, the control valve 116 is closed in step Sp3 (see FIGS. 15 and 16). However, the timing of closing the control valve 116 is not limited to this, and from the viewpoint of appropriately evacuating the inside of the flow rate controller 111 shown in the first embodiment, it is desirable to close the control valve 116 after the first evacuation step (step Sp4).

[0105] Next, the primary side valve 121b and the control valve 116 of the flow rate control unit 110b are opened (see FIG. 16(b)), and the O 2 for the flow rate controller 111 of the flow rate control unit 110b is ２ Gas filling is started (step Sp6 in FIG. 15). In step Sp6, O 2 is introduced into the plasma processing chamber 10. ２ Prior to supplying the gas, the flow rate controller 111 ２ The gas is filled and the internal supply pipe 112 is pressurized (second precharge process).

[0106] It is desirable to increase the internal pressure of the internal supply pipe 112 (more specifically, the internal pressure P2 of the secondary-side internal supply pipe 112b) to a level that is approximately equal to the internal pressure of the secondary-side supply pipe 140. Specifically, it is desirable to increase the internal pressure to approximately 80 to 120% of the internal pressure of the secondary-side supply pipe 140. If the internal pressure of the internal supply pipe 112 is less than 80% of the internal pressure of the secondary-side supply pipe 140, there is a risk that the start-up response of the etching process will deteriorate as described above. Furthermore, if the internal pressure of the internal supply pipe 112 exceeds 120% of the internal pressure of the secondary-side supply pipe 140, O 2 will flow from the internal supply pipe 112 to the plasma processing chamber 10. ２There is a risk that the gas will flow in all at once, causing the spike S described above.

[0107] In addition, the O ２ The gas filling is performed at least in the etching step (step Sp7) described later. ２ It is desirable that the flow rate be smaller than the supply flow rate of the gas. More specifically, as shown in FIG. ２ The opening of the control valve 116 during gas filling is preferably controlled to be smaller than the opening of the control valve 116 during the etching step (step Sp7).

[0108] When the pressure inside the internal supply pipe 112 is increased to a desired pressure, the secondary valve 141b is then opened (see FIG. 16(c)), and O 2 is introduced into the plasma processing chamber 10. ２ The supply of gas is started, and at the same time, the supply of an RF signal (RF power) from the RF power source 31 to the lower electrode and / or upper electrode of the substrate support 11 is started, thereby starting the etching process described above (step Sp7 in FIG. 15).

[0109] In the timing diagram shown in FIG. 15, the O ２ The gas supply (opening of the secondary valve 141a) and the RF signal (RF power) from the RF power source 31 were performed almost simultaneously. ２ It takes time for the gas to reach the inside of the plasma processing chamber 10. In view of this, it is desirable to supply the RF signal (RF power) at a timing shifted from the opening of the secondary valve 141a.

[0110] After etching of the substrate W is completed, the primary valve 121b, the control valve 116, and the secondary valve 141b of the flow rate control unit 110b are closed to stop the flow of O 2 into the plasma processing chamber 10. ２ The gas supply is stopped (step Sp8 in FIG. 15: see FIG. 16(d)).

[0111] Next, as shown in FIG. 16(e), the primary side exhaust valve 132b and the secondary side exhaust valve 152b of the flow rate control unit 110b are opened, and O ２ The inside of the flow rate control unit 110b (flow rate controller 111) that has supplied the gas is evacuated (second evacuation step: step Sp9 in FIG. 15).

[0112] 16(f), the primary-side exhaust valve 132b and secondary-side exhaust valve 152b of the flow control unit 110b are closed to stop exhausting the flow control unit 110b (step Sp10 of FIG. 15). After the second exhaust step (step Sp9) is completed, the control valve 116 of the flow controller 111b and the secondary-side valve 141b of the flow control unit 110b may be opened to confirm that the residual gas in the flow controller 111b has been properly exhausted.

[0113] In the above description, the control valve 116 is closed in step Sp8 (see FIGS. 15 and 16). However, the timing of closing the control valve 116 is not limited to this, and from the viewpoint of appropriately evacuating the inside of the flow rate controller 111 shown in the first embodiment, it is desirable to close the control valve 116 after the second evacuation step (step Sp9).

[0114] In this embodiment, a cycle including the above-mentioned deposition process (first process: steps Sp1 to Sp5) and etching process (second process: steps Sp6 to Sp10) is repeatedly executed until a desired etching amount is obtained for the substrate W.

[0115] After that, when the cycle has been repeated a desired number of times, it is determined whether further cycles of the etching process (deposition process and etching process) are necessary, and if it is determined that further cycles of the etching process are necessary, the process returns to step Sp1 as shown in Fig. 15, and the first and second processes are repeated. If it is determined that further cycles of the etching process are not necessary, the series of etching processes is terminated.

[0116] In the above embodiment, the first precharge process (step Sp1), the deposition process (step Sp2), the first exhaust process (step Sp4), the second precharge process (step Sp6), the etching process (step Sp7), and the second exhaust process (step Sp10) are performed sequentially in one cycle, but the etching process method is not limited to this.

[0117] For example, as shown in FIG. 17, the second exhaust process (internal exhaust of the flow rate control unit 110b) may be performed during the deposition process (supply of CF-based gas from the flow rate control unit 110a). Similarly, the first exhaust process (internal exhaust of the flow rate control unit 110a) may be performed during the etching process (supply of O 2 from the flow rate control unit 110b). ２ In this way, when one flow rate control unit 110 is supplying gas, the exhaust process of another flow rate control unit 110 that is not supplying gas can be simultaneously performed, thereby improving the throughput of the etching process.

[0118] Furthermore, in the above embodiment, while the gas supply to the plasma processing chamber 10 in one flow control unit 110 is stopped (during the first process or the second process), the one flow control unit 110 is sequentially evacuated (first evacuation step or second evacuation step) and filled with gas (pre-charge process). However, these evacuation and pre-charge steps may be omitted as appropriate. Specifically, as shown in FIG. 18 , for example, when only one type of gas is supplied to one flow control unit 110 (having a single-system structure), the evacuation step may be omitted and the pre-charge process may be immediately performed after the first process or the second process is completed, depending on the internal pressure of the flow control unit 110. More specifically, for example, when the internal pressure of the flow control unit 110 is approximately the same as the internal pressure of the secondary supply pipe 140 and it is determined that gas supply can be appropriately started at the start of the next process, the evacuation step may be omitted. Also, for example, as shown in FIG. 18, when the flow rate of Ar gas supplied from another gas supply unit 160 is small and the internal pressure of the secondary side supply pipe 140 is low, the precharge process may be omitted and the treatment process may be started after the exhaust process is completed.

[0119] 4 to 7, the flow control unit 110 is configured to be able to be evacuated from both the upstream and downstream sides thereof, but in this embodiment (second embodiment), it is sufficient that an exhaust unit (exhaust unit 151 in the illustrated example) is connected at least downstream of the flow control unit 110. In other words, particularly according to this embodiment (second embodiment), the flow control unit 110 according to the technology of the present disclosure does not need to include a primary-side exhaust pipe 130, an exhaust unit 131, and a primary-side exhaust valve 132, as shown in FIG.

[0120] <Effects of Wafer Processing According to Second Embodiment> As described above, according to the plasma processing apparatus 1 according to the second embodiment, prior to supplying gas to the plasma processing chamber 10, the flow rate controller 111 is filled with gas, and the internal supply pipe 112 is pressurized (pre-charge process). The internal pressure of the internal supply pipe 112 (more specifically, the internal pressure P2 of the secondary-side internal supply pipe 112b) after the pre-charge process is, for example, a pressure that is approximately the same as the internal pressure of the secondary-side supply pipe 140, and preferably a pressure that is approximately 80 to 120% of the internal pressure of the secondary-side supply pipe 140. This reduces the difference in internal pressure between the internal supply pipe 112 and the secondary-side supply pipe 140, suppresses the inflow of argon gas and the occurrence of spikes S when the secondary-side valve 141 is opened, and suppresses deterioration of the startup response during etching processing.

[0121] 20 is a graph showing the results of an investigation into the gas response of the plasma processing in the processing method according to this embodiment. ２ When the gas was precharged at 0.9 sccm for 0.5 seconds (Example 1), the dashed line indicates O ２ The dashed line shows the results when the gas was precharged at 0.9 sccm for 0.2 seconds (Example 2), and the dashed line shows the results when the precharge was not performed (Comparative Example). Note that in this study, in all of Examples 1 and 2 and the Comparative Example, Ar gas was continuously supplied from the other gas supply unit 160 at 950 sccm.

[0122] 20, it can be seen that filling the flow rate controller 111 with gas prior to supplying gas to the plasma processing chamber 10 can improve the rise response (i.e., the slope of the graph shown in FIG. 20 can be made steeper). It can also be seen that the longer the pre-charge process is performed, the more the rise response can be improved (i.e., the slope of the graph shown in FIG. 20 can be made steeper). This is thought to be because, when gas is supplied at a constant flow rate, the longer the pre-charge process is performed, the smaller the difference in internal pressure between the internal supply pipe 112 and the secondary supply pipe 140 becomes.

[0123] In the precharge process according to this embodiment, it is desirable to determine the time of the precharge process so that the internal pressure of the internal supply pipe 112 is approximately equal to the internal pressure of the secondary supply pipe 140 (approximately 80 to 120% of the internal pressure of the secondary supply pipe 140).

[0124] In the above embodiment, after the pressure inside the internal supply pipe 112 is increased to the desired pressure in the pre-charge process, the secondary side valve 141 is opened to start various treatment processes, but the start conditions of the treatment processes (the opening conditions of the secondary side valve 141) are not limited to the internal pressure of the internal supply pipe 112.

[0125] For example, in the above embodiment, the timing of opening the secondary-side valve 141 is determined by measuring the internal pressure of the internal supply pipe 112. However, conversely, the timing of opening the secondary-side valve 141 may be determined in advance and the internal pressure of the internal supply pipe 112 may be adjusted accordingly. In such a case, the timing of opening the secondary-side valve 141 may be determined based on, for example, the timing of starting the supply of Ar gas from the other gas supply unit 160 in step Sp0.

[0126] In the precharge process before various treatment processes, the aperture of the control valve 116 is adjusted as appropriate so that the internal pressure of the internal supply pipe 112 becomes a desired value at the timing of opening the secondary side valve 141 determined in this manner. That is, for example, if it is predicted that the internal pressure of the internal supply pipe 112 will be higher than the desired value at the timing of opening the secondary side valve 141, the aperture of the control valve 116 is controlled to be smaller. Also, for example, if it is predicted that the internal pressure of the internal supply pipe 112 will be lower than the desired value at the timing of opening the secondary side valve 141, the aperture of the control valve 116 is controlled to be larger.

[0127] In the above embodiment, the timing of opening the secondary-side valve 141 is determined based on the internal pressure of the internal supply pipe 112 where the precharge process has been performed, but other parameters may be set as conditions instead of or in addition to the internal pressure of the internal supply pipe 112. Specifically, for example, instead of or in addition to the internal pressure of the internal supply pipe 112, the flow rate of the gas supplied from the flow rate controller 111, the gas supply time, the internal temperature of the flow rate controller 111, the flow rate of the Ar gas flowing through the secondary-side supply pipe 140, an mechanical error of the control valve 116, or the like may be used as parameters to set the conditions.

[0128] Furthermore, the flow rate of the gas supplied from the flow rate controller 111, the internal temperature of the flow rate controller 111, the flow rate of the Ar gas flowing through the secondary side supply pipe 140, etc. may be used as parameters to further adjust the opening degree of the control valve 116 in addition to the timing of opening the secondary side valve 141.

[0129] The precharge process performed as described above can be applied in various aspects shown in the following phases.

[0130] Phase 1: Prior to the start of plasma processing, the precharge process may be executed using a predetermined model recipe. Specifically, as described above, the conditions for precharge, such as the gas supply flow rate and supply time, may be determined in advance, and the precharge process may be executed in accordance with the determined conditions (e.g., gas supply flow rate). Phase 1 allows the plasma processing of the substrate W to be performed appropriately by setting conditions in advance that improve the rise response and prevent spikes from occurring, and then executing the precharge process.

[0131] Phase 2: The precharge process can be automatically executed under appropriate conditions (e.g., gas supply flow rate, filling amount) by calculating from the flow rate of Ar gas as a carrier gas, the temperature of the shower head 13, or the flow rate ratio of the gases supplied to the gas supply ports 14c, 14m, and 14e of the shower head 13, or by measuring the internal pressure P2 using the pressure sensor 115. In Phase 2, the precharge process is appropriately controlled based on various measurement and calculation results. This allows the precharge process to be appropriately changed in accordance with the internal state of the flow controller 111 and the plasma processing chamber 10, thereby achieving more appropriate plasma processing results than in Phase 1.

[0132] Phase 3 The precharge process can be performed using a flow control unit 110 or a flow controller 111 equipped with a mechanism for controlling the internal pressure of the internal supply pipe 112 (more specifically, the internal pressure P2 of the secondary-side internal supply pipe 112b). Phase 3 has the advantage of eliminating the need to strictly control the filling amount before opening the valve. Furthermore, because the control can be unified by the internal pressure control mechanism, it is possible to mitigate the effects of individual differences in the flow control unit 110 or the flow controller 111 and the effects of variations in control reproduction.

[0133] <Other Effects of the Technique of the Present Disclosure> In the plasma processing apparatus 1 according to the technique of the present disclosure, as described above, a cycle including the first process and the second process is repeatedly and alternately performed on the substrate W. Therefore, in each flow rate controller 111, the supply and stop of gas to the plasma processing chamber 10 (exhaust by the exhaust unit 151) are repeatedly performed.

[0134] In a conventional plasma processing apparatus in which an exhaust line (secondary exhaust pipe 150 and exhaust unit 151) is not connected downstream of orifice 113, it is necessary to stop the supply of gas from gas source 100 each time (close primary valve 121 each time) to prevent the internal pressure of flow controller 111 from rising and causing spike S. In other words, it is necessary to control the gas flow rate using flow controller 111 for each cycle that is repeatedly executed, and it takes time to switch between supplying and stopping the gas to plasma processing chamber 10.

[0135] In this regard, in the plasma processing apparatus 1 according to this embodiment, an exhaust line (secondary-side exhaust pipe 150 and exhaust unit 151) is connected downstream of the orifice 113. Therefore, when stopping the gas supply to the plasma processing chamber 10, it is not necessary to stop the gas supply from the gas source 100 (by closing the primary-side valve 121). Instead, the secondary-side exhaust valve 152 is opened to continue exhausting at a constant flow rate (the supply flow rate to the plasma processing chamber 10). In other words, the gas supply to the plasma processing chamber 10 can be switched on and off simply by repeatedly opening and closing the secondary-side valve 141 and the secondary-side exhaust valve 152, respectively. This does not require the flow rate controller 111 to control the gas flow rate. That is, the gas flow rate control by the flow rate controller 111, which has conventionally been performed for each cycle, can be omitted, and the gas supply to the plasma processing chamber 10 can be instantly resumed at a desired constant flow rate.

[0136] In the above embodiment, the orifice 113 as a control side orifice for controlling the gas flow rate in the gas supply unit 20 is arranged only inside the flow rate controller 111, but another orifice for controlling the gas flow rate may be further provided in the gas supply flow path.

[0137] Here, there is a minimum processing limit for the hole diameter of the orifice provided in the gas supply flow path, and therefore, in principle, gas cannot be flowed through the gas supply flow path at an extremely small flow rate below the flow rate that can be controlled with the hole diameter at the minimum processing limit. However, after investigations, the inventors of the present invention found that it is possible to supply gas at an extremely small flow rate by providing an orifice 180 as a chamber-side orifice and an orifice 181 as an exhaust-side orifice respectively between the connection part of secondary-side supply pipe 140 with secondary-side exhaust pipe 150 and secondary-side valve 141, and on the upstream side of secondary-side exhaust valve 152 in secondary-side exhaust pipe 150, as shown in Figure 21.

[0138] Specifically, the diameter of the orifice 113 disposed inside the flow rate controller 111 is set to the minimum processing limit, and the orifices 180 and 181 provided downstream of the orifice 113 are set to different diameters.

[0139] As a result, gas supplied from the gas source 100 to the flow rate controller 111 is first introduced into the secondary supply pipe 140 at the minimum flow rate that can be controlled by the orifice 113 with the minimum processing limit hole diameter. The gas introduced into the secondary supply pipe 140 branches at the connection with the secondary exhaust pipe 150. At this time, since the orifices 180 and 181 have different hole diameters, the flow rate ratio of the gas flowing toward the orifice 180 (plasma processing chamber 10) and the orifice 181 (exhaust unit 151) changes depending on the ratio of the hole diameters. That is, for example, if the hole diameter ratio of the orifices 180 and 181 is 1:4, 20% of the gas introduced into the secondary supply pipe 140 at the minimum flow rate flows toward the plasma processing chamber 10, and the remaining 80% flows toward the exhaust unit 151.

[0140] As described above, according to this embodiment, by providing additional orifices 180, 181 in the gas supply flow path for controlling the gas flow rate, gas can be supplied to the plasma processing chamber 10 at an extremely small flow rate that is equal to or less than the flow rate that can be controlled by the minimum process limit hole diameter of the orifice 113. In this case, the hole diameter ratio of the orifices 180, 181 is determined based on the ratio of the target gas flow rate to be supplied to the plasma processing chamber 10 to the minimum gas flow rate output from the orifice 113. This enables more precise control of the processing of the substrate W in the plasma processing chamber 10.

[0141] 21, the flow rate ratio of the gases flowing to the plasma processing chamber 10 side and the exhaust unit 151 side is controlled by providing orifices 180, 181 with different hole diameters, but the method of controlling the flow rate ratio is not limited to this. Specifically, the flow rate ratio of the gases can be controlled if the flow paths of the secondary exhaust pipe 150 and the secondary supply pipe 140 downstream of the connection portion with the secondary exhaust pipe 150 are different in size. For example, instead of providing orifices 180, 181, the secondary valve 141 and the secondary exhaust valve 152 may each be configured as a valve whose opening is adjustable, such as a needle valve.

[0142] In plasma processing apparatuses, the flow rate of gas flowing through a gas supply passage is calculated using an orifice provided in a flow rate controller, but if impurities or the like adhere to or accumulate in the orifice hole, the gas flow rate may not be calculated properly. For this reason, plasma processing apparatuses have conventionally performed self-diagnosis (to verify the validity of the calculated gas flow rate) using the drop characteristics of the orifice.

[0143] In a conventional orifice self-diagnosis, the gas filled inside the flow controller is exhausted from the plasma processing chamber by closing the primary valve and the primary exhaust valve and opening the secondary valve. Then, by checking whether the exhaust characteristics, which are the rate of pressure decrease of the flow controller with respect to the exhaust time, are appropriate (for example, whether there has been any change from the state at the time of shipment), it is determined (self-diagnosis) whether the calculated gas flow rate is valid. However, when performing self-diagnosis using this conventional method, the flow controller is exhausted from the plasma processing chamber, so the orifice self-diagnosis and the processing of the substrate W in the plasma processing chamber cannot be performed in parallel.

[0144] However, in the plasma processing apparatus 1 according to this embodiment, the exhaust unit 151 connected to the secondary supply pipe 140 can be used to evacuate the flow rate controller 111, instead of the exhaust system 40 connected to the plasma processing chamber 10. That is, the self-diagnosis of the orifice 113 can be performed independently of (in parallel with) the processing of the substrate W in the plasma processing chamber 10. This eliminates the need to stop the processing of the substrate W during the self-diagnosis of the orifice 113, thereby improving the productivity of the plasma processing apparatus 1. Furthermore, since the self-diagnosis can be performed independently of the processing of the substrate W, the self-diagnosis can be performed at any timing, such as after each processing of a single substrate W in the plasma processing chamber 10 or after each processing step of the substrate W shown in FIG. 9 , and the number of scrapped substrates W due to improper calculation of the gas flow rate can be appropriately reduced.

[0145] In addition, in the plasma processing apparatus 1 of this embodiment, similar to the self-diagnosis of the orifice described above, the self-diagnosis of the two pressure sensors 114, 115 provided in the flow controller can be performed independently of the processing of the substrate W (in parallel with the processing of the substrate W).

[0146] Specifically, the gas filled inside the flow rate controller 111 is exhausted by the exhaust unit 151 by closing the primary side valve 121 and the primary side exhaust valve 132 and opening the secondary side exhaust valve 152. At this time, the internal pressure of the flow rate controller 111 is measured by the two pressure sensors 114, 115, and by comparing the measurement results with each other, it can be confirmed whether or not a zero point deviation or span deviation has occurred in these two pressure sensors 114, 115.

[0147] More specifically, by comparing the measurement results of the two pressure sensors 114, 115 with each other when the pressure is increased after the inside of the flow controller 111 is filled with gas and when the exhaust unit 151 is exhausting the gas, it is possible to check whether span deviation has occurred in these two pressure sensors 114, 115. Furthermore, by comparing the measurement results of the two pressure sensors 114, 115 with each other after the gas inside the flow controller 111 has been sufficiently exhausted and the inside of the flow controller 111 has been evacuated, it is possible to check whether zero-point deviation has occurred in these two pressure sensors 114, 115.

[0148] The self-diagnosis of these pressure sensors 114, 115 may be performed in parallel with the self-diagnosis of the orifice 113. That is, for example, prior to the self-diagnosis of the orifice 113, the span misalignment of the pressure sensors 114, 115 may be checked when the inside of the flow rate controller 111 is filled with gas, and then the filled gas may be exhausted and the self-diagnosis of the orifice 113 may be performed, and then the internal pressure of the flow rate controller 111 after evacuation may be measured to check the zero point misalignment of the pressure sensors 114, 115.

[0149] As shown in Figures 4 and 5, in the gas supply unit 20 according to the above embodiment, the secondary exhaust pipes 150 connected to the respective flow rate controllers 111 join together downstream of the secondary exhaust valves 152 and are then exhausted by the exhaust unit 151.

[0150] In consideration of this, when a non-mixing gas is contained in the gases simultaneously exhausted from each secondary-side exhaust pipe 150, it is desirable to control the opening and closing of each secondary-side exhaust valve 152 so that the non-mixing gases do not mix with each other in the exhaust line. More specifically, when exhausting two or more types of gases that are dangerous to mix, it is desirable to individually exhaust one gas, empty the exhaust line for a predetermined delay time (e.g., 100 msec), and then individually exhaust the other gases.

[0151] The prohibited gas combinations are hydrogen (H ２ ) gas and oxygen (O ２ ) gas combination, hydrogen bromide (HBr) gas and chlorine (Cl ２ ) gas combination, or ammonia (NH ３ ) gas and chlorine (Cl ２ ) gas combinations, etc.

[0152] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0153] The following configurations also belong to the technical features of the present disclosure: (1) A gas supply system that supplies gas into a processing chamber, the gas supply system comprising: a plurality of gas supply flow paths configured to be able to independently supply gas to the processing chamber; a flow rate controller disposed in each of the plurality of gas supply flow paths; a primary-side valve disposed in the gas supply flow paths upstream of the flow rate controller; a primary-side gas exhaust flow path that branches off between the flow rate controller and the primary-side valve in the gas supply flow path and is connected to a primary-side exhaust mechanism; a primary-side exhaust valve disposed in the primary-side gas exhaust flow path; a secondary-side valve disposed in the gas supply flow path downstream of the flow rate controller; a secondary-side gas exhaust flow path that branches off between the flow rate controller and the secondary-side valve in the gas supply flow path and is connected to a secondary-side exhaust mechanism; and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path, wherein the flow rate controller comprises a control valve connected to the primary-side valve and the secondary-side valve, and a control-side orifice disposed between the control valve and the secondary-side valve. (2) The gas supply system according to (1), further comprising: an exhaust-side orifice disposed upstream of the secondary-side exhaust valve in the secondary-side gas exhaust flow path; and a chamber-side orifice disposed in the gas supply flow path between a connection portion with the secondary-side gas exhaust flow path and the secondary-side valve, wherein the control-side orifice has a minimum processing limit hole diameter, and the hole diameters of the exhaust-side orifice and the chamber-side orifice are different from each other. (3) The gas supply system according to (2), wherein a ratio of the hole diameters of the exhaust-side orifice and the chamber-side orifice is determined based on a ratio of a target flow rate to be supplied to the processing chamber to a flow rate of gas output from the control-side orifice. (4) The gas supply system according to any of (1) to (3), wherein the multiple gas supply flow paths are joined downstream of the secondary-side valve and then connected to the processing chamber.(5) The gas supply system according to any one of (1) to (4), wherein the gas supply flow path has a plurality of branch supply pipes that independently supply gas to a plurality of different positions inside the processing chamber, and the flow rate controller, the secondary valve, the secondary gas exhaust flow path, and the secondary exhaust valve are independently connected to each of the plurality of branch supply pipes. (6) The gas supply system according to (5), wherein the gas supply flow path branches into the plurality of branch supply pipes between a connection portion with the primary gas exhaust flow path and the flow rate controller. (7) The gas supply system according to (5) or (6), wherein the plurality of branch supply pipes are configured to independently supply the gas to at least an edge region and a center region of a substrate introduced inside the processing chamber. (8) A plasma processing apparatus for processing a substrate, comprising: a processing chamber; a substrate support disposed inside the processing chamber; a gas supply system according to any one of (1) to (7) that supplies gas into the processing chamber; and a plasma generating unit configured to generate plasma from the gas in the processing chamber.(9) A gas supply method using a gas supply system, the gas supply system including: a plurality of gas supply flow paths configured to be able to supply gas independently to a processing chamber; flow rate controllers arranged in each of the plurality of gas supply flow paths; a primary-side valve arranged upstream of the flow rate controller in the gas supply flow paths; a primary-side gas exhaust flow path branching between the flow rate controller and the primary-side valve in the gas supply flow path and connected to a primary-side exhaust mechanism; a primary-side exhaust valve arranged in the primary-side gas exhaust flow path; a secondary-side valve arranged downstream of the flow rate controller in the gas supply flow path; a secondary-side gas exhaust flow path branching between the flow rate controller and the secondary-side valve in the gas supply flow path and connected to a secondary-side exhaust mechanism; and a secondary-side exhaust valve arranged in the secondary-side gas exhaust flow path, the amount controller has a control valve connected to the primary-side valve and the secondary-side valve, and a control-side orifice disposed between the control valve and the secondary-side valve, and the gas supply method includes the steps of: (A) opening the primary-side valve and the secondary-side valve of at least one of the gas supply passages to supply gas into the interior of the processing chamber; (B) closing the primary-side valve and the secondary-side valve opened in step (A); (C) opening the primary-side exhaust valve and the secondary-side exhaust valve of the at least one gas supply passage that supplied gas into the interior of the processing chamber in step (A) to exhaust gas from the at least one gas supply passage; and (D) closing the primary-side exhaust valve and the secondary-side exhaust valve opened in step (C). (10) The gas supply method according to (9), further comprising the step of: (E) closing the primary exhaust valve and the secondary exhaust valve, and then opening the secondary valve to check for gas remaining inside the flow rate controller. (11) The gas supply method according to (9) or (10), further comprising the step of repeatedly executing a cycle including at least the steps (A) to (D).(12) A gas supply method using a gas supply system, the gas supply system including: a plurality of gas supply flow paths configured to be able to supply gases independently to a processing chamber; flow rate controllers arranged in each of the plurality of gas supply flow paths; a primary-side valve arranged upstream of the flow rate controller in the gas supply flow paths; a primary-side gas exhaust flow path branching between the flow rate controller and the primary-side valve in the gas supply flow path and connected to a primary-side exhaust mechanism; a primary-side exhaust valve arranged in the primary-side gas exhaust flow path; a secondary-side valve arranged downstream of the flow rate controller in the gas supply flow path; and a secondary-side gas exhaust flow path branching between the flow rate controller and the secondary-side valve in the gas supply flow path and connected to the secondary-side exhaust mechanism. and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path, wherein the flow rate controller has a control valve connected to the primary-side valve and the secondary-side valve, and a control-side orifice disposed between the control valve and the secondary-side valve, and the gas supply method alternately repeats the steps of: (A) opening the primary-side valve and the secondary-side valve of the gas supply flow path and closing the primary-side exhaust valve and the secondary-side exhaust valve to supply gas into the processing chamber; and (B) opening the primary-side valve and the secondary-side exhaust valve of the gas supply flow path and closing the primary-side exhaust valve and the secondary-side valve to exhaust gas from the gas supply flow path.(13) The gas supply method according to any one of (9) to (12), wherein the flow rate controller has at least one pressure sensor, and includes supplying gas from at least one of the plurality of gas supply flow paths into the processing chamber, and performing self-diagnosis of the flow rate controller arranged in another of the plurality of gas supply flow paths, wherein the self-diagnosis of the flow rate controller includes filling the interior of the flow rate controller arranged in the other of the gas supply flow paths with gas, opening the secondary-side exhaust valve of the other of the gas supply flow paths to exhaust the gas filled in the interior of the flow rate controller, and comparing an actual measurement value of the drop characteristic of the internal pressure of the flow rate controller when the filled gas is exhausted with the drop characteristic at the time of shipment of the flow rate controller. (14) The gas supply method according to (13), wherein the flow rate controller has a plurality of pressure sensors, and during self-diagnosis of the flow rate controller, the internal pressure of the flow rate controller after the gas has been filled and the internal pressure of the flow rate controller after the filled gas has been exhausted are measured by the plurality of pressure sensors, and the measured values ​​of the internal pressure measured by each of the plurality of pressure sensors are compared with each other.

[0154] (15) A gas control system for controlling the supply of gas into a processing chamber, comprising: a plurality of gas supply flow paths configured to be able to supply gas to the processing chamber independently; an orifice disposed in each of the plurality of gas supply flow paths; a primary-side valve disposed upstream of the orifice in the gas supply flow path; a primary-side gas exhaust flow path branching between the orifice in the gas supply flow path and the primary-side valve and connected to a primary-side exhaust mechanism; a primary-side exhaust valve disposed in the primary-side gas exhaust flow path; a secondary-side valve disposed downstream of the orifice in the gas supply flow path; a secondary-side gas exhaust flow path branching between the orifice in the gas supply flow path and the secondary-side valve and connected to a secondary-side exhaust mechanism; and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path. and a control unit that independently controls openings of the primary-side valve, the primary-side exhaust valve, the secondary-side valve, and the secondary-side exhaust valve, wherein the control unit alternately performs control to supply gas into the processing chamber by opening the primary-side valve and the secondary-side valve and closing the primary-side exhaust valve and the secondary-side exhaust valve, and control to evacuate the inside of the gas supply flow path by closing the primary-side valve and the secondary-side valve and opening the primary-side exhaust valve and the secondary-side exhaust valve, and also performs control to operate the primary-side exhaust mechanism and the secondary-side exhaust mechanism when evacuating the inside of the gas supply flow path so that the internal pressure of the gas supply flow path is at least lower than the internal pressure of the processing chamber.(16) A gas control system for controlling the supply of gas into a processing chamber, the system comprising: a gas supply flow path configured to be able to supply gas to the processing chamber; an orifice disposed in the gas supply flow path; a primary-side valve disposed upstream of the orifice in the gas supply flow path; a primary-side gas exhaust flow path branching between the orifice in the gas supply flow path and the primary-side valve and connected to a primary-side exhaust mechanism; a primary-side exhaust valve disposed in the primary-side gas exhaust flow path; a secondary-side valve disposed downstream of the orifice in the gas supply flow path; a secondary-side gas exhaust flow path branching between the orifice in the gas supply flow path and the secondary-side valve and connected to a secondary-side exhaust mechanism; a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path; and a control unit that independently controls openings of a primary-side exhaust valve, the secondary-side valve, and the secondary-side exhaust valve, wherein the control unit alternately performs control to supply gas into the processing chamber by opening the primary-side valve and the secondary-side valve and closing the primary-side exhaust valve and the secondary-side exhaust valve, and control to exhaust the inside of the gas supply flow path by closing the primary-side valve and the secondary-side valve and opening the primary-side exhaust valve and the secondary-side exhaust valve, and also performs control to operate the primary-side exhaust mechanism and the secondary-side exhaust mechanism when exhausting the inside of the gas supply flow path so that at least the gas remains inside the gas supply flow path, wherein an internal pressure of the gas supply flow path after exhausting is 100 Torr or less. (17) The gas control system according to (16), further comprising a plurality of gas supply flow paths configured to be able to supply gas independently to the processing chamber, wherein the orifice, the primary valve, the primary exhaust valve, the secondary valve, and the secondary exhaust valve are disposed in each of the plurality of gas supply flow paths. (18) The gas control system according to (15) or (17), further comprising a plurality of gas supply flow paths that are joined downstream of the secondary valve and then connected to the processing chamber.(19) The gas control system according to any one of (15) to (18), wherein the gas supply flow path has a plurality of branch supply pipes that independently supply the gas to a plurality of different positions inside the processing chamber, and the secondary-side valve, the secondary-side gas exhaust flow path, and the secondary-side exhaust valve are independently connected to each of the plurality of branch supply pipes. (20) The gas control system according to claim 5, wherein the gas supply flow path branches into the plurality of branch supply pipes downstream of a connection portion with the primary-side gas exhaust flow path. (21) The gas control system according to (19) or (20), wherein the plurality of branch supply pipes are configured to be able to independently supply the gas to at least an edge region and a center region of a substrate introduced inside the processing chamber. (22) The gas control system according to any one of (15) to (21), further comprising a flow rate controller that controls a flow rate of the gas supplied into the processing chamber, wherein the orifice is disposed inside the flow rate controller, and the primary-side valve, the primary-side exhaust valve, the secondary-side valve, and the secondary-side exhaust valve are disposed outside the flow rate controller. (23) The gas control system according to (22), wherein the flow rate controller further comprises an aperture adjustment valve that is disposed upstream of the orifice in the gas supply flow path. (24) The gas control system according to any one of (15) to (23), further comprising a mounting member that connects the orifice, the primary-side valve, the primary-side exhaust valve, the secondary-side valve, and the secondary-side exhaust valve together. (25) The gas control system according to any one of (15) to (24), wherein the flow rate of the gas supplied into the processing chamber is 0.1 sccm to 10 sccm.(26) The gas control system according to any one of (15) to (25), wherein the control unit executes control to alternately and repeatedly execute a deposition process for forming a deposit on a substrate introduced into the processing chamber and an etching process for etching the substrate, the deposition process and the etching process each having a step of supplying a gas into the processing chamber and a step of evacuating the inside of the gas supply passage, and the processing time of one cycle including the deposition process and the etching process is 1 to 10 seconds. (27) a primary-side valve arranged upstream of the orifice in each of the gas supply flow paths; a primary-side gas exhaust flow path branching between the orifice in each of the gas supply flow paths and the primary-side valve and connected to a primary-side exhaust mechanism; a primary-side exhaust valve arranged in each of the gas supply flow paths; a secondary-side valve arranged downstream of the orifice in each of the gas supply flow paths; a primary-side exhaust valve arranged in each of the gas supply flow paths; a gas control system including a secondary-side gas exhaust flow path branching off from the secondary-side valve and connected to a secondary-side exhaust mechanism, and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path, wherein the control unit performs control to alternately repeat the steps of: supplying gas into the processing chamber by opening the primary-side valve and the secondary-side valve and closing the primary-side exhaust valve and the secondary-side exhaust valve; and exhausting the inside of the gas supply flow path by closing the primary-side valve and the secondary-side valve and opening the primary-side exhaust valve and the secondary-side exhaust valve; and control to operate the primary-side exhaust mechanism and the secondary-side exhaust mechanism when exhausting the inside of the gas supply flow path so that the internal pressure of the gas supply flow path is at least lower than the internal pressure of the processing chamber.(28) A gas control method using a gas control system, the gas control system including: a plurality of gas supply flow paths configured to be able to supply gas independently to a processing chamber; an orifice disposed in each of the plurality of gas supply flow paths; a primary-side valve disposed upstream of the orifice in the gas supply flow path; and a primary-side gas exhaust flow path branching between the orifice in the gas supply flow path and the primary-side valve and connected to a primary-side exhaust mechanism. a secondary-side exhaust valve disposed in the primary-side gas exhaust flow path; a secondary-side valve disposed downstream of the orifice in the gas supply flow path; a secondary-side gas exhaust flow path branched between the orifice in the gas supply flow path and the secondary-side valve and connected to a secondary-side exhaust mechanism; and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path, wherein (A) the primary-side valve and the secondary-side valve of a first gas supply flow path group, at least one of which is selected from a plurality of the gas supply flow paths, are opened, and the primary-side exhaust valve and the secondary-side exhaust valve of the first gas supply flow path group, and the primary-side valve, the secondary valve, the primary-side exhaust valve and the secondary-side exhaust valve of another gas supply flow path are opened. (B) closing the primary-side valve and the secondary-side valve in the first gas supply flow path group, and then opening the primary-side exhaust valve and the secondary-side exhaust valve of the first gas supply flow path group, (C) closing the primary-side exhaust valve and the secondary-side exhaust valve in the first gas supply flow path group, and then opening the primary-side valve and the secondary-side valve of a second gas supply flow path group, at least one of which is selected from the other gas supply flow paths, and (D) closing the primary-side valve and the secondary-side valve in the second gas supply flow path group, and then opening the primary-side exhaust valve and the secondary-side exhaust valve of the second gas supply flow path group. (29) The gas control method according to (28), in which a first process including the steps (A) and (B) and a second process including the steps (C) and (D) are alternately and repeatedly performed.

[0155] (30) A gas control system for controlling the supply of gas into a processing chamber, comprising: a gas supply flow path configured to be able to supply gas to the processing chamber; an orifice disposed in the gas supply flow path; a flow control valve disposed upstream of the orifice in the gas supply flow path; a primary valve disposed upstream of the flow control valve in the gas supply flow path; a secondary valve disposed downstream of the orifice in the gas supply flow path; a secondary gas exhaust flow path branched between the orifice in the gas supply flow path and the secondary valve and connected to a secondary exhaust mechanism; a secondary exhaust valve disposed in the secondary gas exhaust flow path; and a flow control valve, the primary valve, the secondary valve, and the secondary exhaust. a control unit that independently controls the opening of the valves, wherein the control unit alternately executes a step of supplying gas into the processing chamber by opening the flow control valve, the primary-side valve, and the secondary-side valve and closing the primary-side exhaust valve and the secondary-side exhaust valve, and a step of evacuating the inside of the gas supply channel by closing the flow control valve, the primary-side valve, and the secondary-side valve and opening the primary-side exhaust valve and the secondary-side exhaust valve, and a control that opens the flow control valve and the primary-side valve before the secondary-side valve during the gas supply step, and opens the secondary-side valve after filling the downstream side of the orifice with gas. (31) The gas control system according to (30), wherein the control unit opens the secondary-side valve after the pressure downstream of the orifice has been increased to a predetermined reference pressure during the gas supply step. (32) The gas control system according to (31), wherein the reference pressure is 80% or more and 120% or less of the pressure on the downstream side of the secondary valve. (33) The gas control system according to (30), wherein the control unit determines the opening timing of the secondary valve using at least one parameter among the pressure on the downstream side of the orifice, the flow rate of gas flowing through the gas supply flow path, the gas supply time, the internal temperature of the gas supply flow path, and the flow rate of another gas flowing downstream of the secondary valve.(34) The gas control system according to any one of (30) to (33), wherein the control unit fills the downstream side of the orifice with gas at a supply flow rate determined prior to the gas filling. (35) The gas control system according to any one of (30) to (33), wherein the gas supply flow path is configured to be able to supply gas independently to different regions in the processing chamber, and the control unit fills the gas at a supply flow rate determined using at least one parameter among the flow rate of another gas flowing downstream of the secondary valve, the temperature of the processing chamber, the flow rate ratio of gases supplied to each of the different regions, and the pressure downstream of the orifice. (36) The gas control system according to any one of (30) to (33), comprising a flow rate controller that controls the pressure downstream of the orifice and controls the flow rate of the gas supplied into the processing chamber. (37) The gas control system according to (36), wherein the orifice is disposed inside the flow rate controller. (38) The gas control system according to any one of (30) to (37), comprising: a primary-side gas exhaust flow path branching between the orifice in the gas supply flow path and the primary-side valve and connected to a primary-side exhaust mechanism, and a primary-side exhaust valve arranged in the primary-side gas exhaust flow path. (39) The gas control system according to any one of (30) to (38), comprising a plurality of the gas supply flow paths configured to be able to independently supply gas to the processing chamber. (40) The gas control system according to (39), wherein different types of gas are independently supplied to each of the plurality of gas supply flow paths, and the control unit executes control to omit a step of exhausting the inside of the gas supply flow path in accordance with the internal pressure of the gas supply flow path.(41) A plasma processing apparatus including a processing chamber, a substrate support part disposed inside the processing chamber, a gas supply part that supplies gas into the processing chamber, a high-frequency power supply connected to at least the substrate support part, and a control part, the plasma processing apparatus including: a gas supply flow path configured to be able to supply gas to the processing chamber; an orifice disposed in the gas supply flow path; a flow control valve disposed upstream of the orifice in the gas supply flow path; a primary-side valve disposed upstream of the flow control valve in the gas supply flow path; a secondary-side valve disposed downstream of the orifice in the gas supply flow path; and a secondary-side gas exhaust flow path that branches between the orifice and the secondary-side valve in the gas supply flow path and is connected to a secondary-side exhaust mechanism. and a secondary-side exhaust valve disposed in the secondary-side gas exhaust flow path, wherein the control unit performs control to alternately and repeatedly perform the steps of: supplying gas into the processing chamber by opening the flow control valve, the primary-side valve, and the secondary-side valve, and closing the primary-side exhaust valve and the secondary-side exhaust valve; and exhausting the inside of the gas supply flow path by closing the flow control valve, the primary-side valve, and the secondary-side valve, and opening the primary-side exhaust valve and the secondary-side exhaust valve; and performing control to open the flow control valve and the primary-side valve before the secondary-side valve during the gas supply step, and to open the secondary-side valve after filling a gas downstream of the orifice.(42) A method for plasma processing a substrate using a gas control system, the gas control system including: a gas supply flow path configured to be able to supply gas to a processing chamber accommodating the substrate; an orifice disposed in the gas supply flow path; a flow control valve disposed upstream of the orifice in the gas supply flow path; a primary valve disposed upstream of the flow control valve in the gas supply flow path; a secondary valve disposed downstream of the orifice in the gas supply flow path; a secondary gas exhaust flow path branched between the orifice and the secondary valve in the gas supply flow path and connected to a secondary exhaust mechanism; and a secondary-side exhaust valve, the method alternately repeating the following steps: (A) supplying gas into the processing chamber by opening the flow control valve, the primary-side valve, and the secondary-side valve, and closing the primary-side exhaust valve and the secondary-side exhaust valve; and (B) evacuating the inside of the gas supply flow path by closing the flow control valve, the primary-side valve, and the secondary-side valve, and opening the primary-side exhaust valve and the secondary-side exhaust valve, wherein in the step (B), the flow control valve and the primary-side valve are opened before the secondary-side valve, and after filling the downstream side of the orifice with gas, the secondary-side valve is opened.

[0156] While the present invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the present invention, will be apparent to those skilled in the art upon reference to the description. For example, the embodiments of Figures 3-11 may be combined with Figures 15-21 unless inconsistent. Therefore, it is intended that the appended claims cover any such modifications or embodiments.

[0157] REFERENCE SIGNS LIST 10 plasma processing chamber 20 gas supply unit 111 flow rate controller 112 internal supply pipe 113 orifice 116 control valve 120 primary supply pipe 121 primary valve 130 primary exhaust pipe 131 exhaust unit 132 primary exhaust valve 140 secondary supply pipe 141 secondary valve 150 secondary exhaust pipe 151 exhaust unit 152 secondary exhaust valve

Claims

1. A gas supply system that supplies gas into a processing chamber, Multiple gas supply channels configured to independently supply gas to the processing chamber, A flow controller is placed in each of the multiple gas supply channels, A primary valve located upstream of the flow controller in the gas supply channel, A primary gas exhaust passage that branches off between the flow controller and the primary valve in the gas supply passage and is connected to the primary exhaust mechanism, A primary exhaust valve is arranged in the primary gas exhaust passage, A secondary valve located downstream of the flow controller in the gas supply channel, A secondary gas exhaust passage that branches off between the flow controller and the secondary valve in the gas supply passage and is connected to the secondary exhaust mechanism, It has a secondary exhaust valve arranged in the secondary gas exhaust passage, The flow rate controller is A control valve connected to the primary valve and the secondary valve, A gas supply system having a control-side orifice positioned between the control valve and the secondary valve.

2. An exhaust-side orifice is located upstream of the secondary exhaust valve in the secondary gas exhaust passage, The gas supply passage further comprises a chamber-side orifice positioned between the connection point with the secondary gas exhaust passage and the secondary valve, The control-side orifice has a hole diameter that is the minimum machining limit, The gas supply system according to claim 1, wherein the diameters of the exhaust side orifice and the chamber side orifice are different from each other.

3. The gas supply system according to claim 2, wherein the ratio of the diameters of the exhaust-side orifice and the chamber-side orifice is determined based on the ratio of the target flow rate supplied to the processing chamber to the flow rate of the gas output from the control-side orifice.

4. The gas supply system according to claim 1, wherein the plurality of gas supply channels merge downstream of the secondary valve and are then connected to the processing chamber.

5. The gas supply channel has a plurality of branch supply pipes that independently supply gas to a plurality of different locations inside the processing chamber, The gas supply system according to claim 1, wherein each of the multiple branch supply pipes is independently connected to the flow controller, the secondary valve, the secondary gas exhaust passage, and the secondary exhaust valve.

6. The gas supply system according to claim 5, wherein the gas supply passage branches into a plurality of branch supply pipes between the connection point with the primary gas exhaust passage and the flow rate controller.

7. The gas supply system according to claim 5, wherein the plurality of branch supply pipes are configured to independently supply the gas to at least the edge region and the center region of the substrate introduced inside the processing chamber.

8. A plasma processing apparatus for processing substrates, Processing chamber and A substrate support disposed inside the processing chamber, A gas supply system according to any one of claims 1 to 7, which supplies gas inside the processing chamber, A plasma processing apparatus comprising a plasma generation unit configured to generate plasma from the gas in the processing chamber.

9. A gas control system that controls the supply of gas into a processing chamber, A gas supply channel configured to supply gas to the processing chamber, An orifice is placed in the aforementioned gas supply channel, A primary valve located upstream of the orifice in the gas supply passage, A primary gas exhaust passage that branches off between the orifice and the primary valve in the gas supply passage and is connected to the primary exhaust mechanism, A primary exhaust valve is arranged in the primary gas exhaust passage, A secondary valve located downstream of the orifice in the gas supply passage, A secondary gas exhaust passage that branches off between the orifice and the secondary valve in the gas supply passage and is connected to the secondary exhaust mechanism, A secondary exhaust valve is arranged in the secondary gas exhaust passage, The system includes a primary valve, a primary exhaust valve, a secondary valve, and a control unit that independently controls the opening degree of the secondary exhaust valve, The control unit, A step of supplying gas into the processing chamber by opening the primary valve and the secondary valve, and closing the primary exhaust valve and the secondary exhaust valve, A control system that repeatedly alternately performs the following steps: closing the primary valve and the secondary valve, and opening the primary exhaust valve and the secondary exhaust valve to exhaust the inside of the gas supply passage; When exhausting gas from the gas supply channel, control is performed to operate the primary exhaust mechanism and the secondary exhaust mechanism so that at least some of the gas remains inside the gas supply channel. A gas control system in which the internal pressure of the gas supply channel after exhaust is 100 Torr or less.

10. It includes a plurality of gas supply channels configured to independently supply gas to the processing chamber, The gas control system according to claim 9, wherein the orifice, the primary valve, the primary exhaust valve, the secondary valve, and the secondary exhaust valve are arranged in each of the plurality of gas supply passages.

11. The processing chamber further includes a flow controller for controlling the flow rate of the gas supplied inside the chamber. The orifice is located inside the flow controller. The gas control system according to claim 9 or 10, wherein the primary valve, the primary exhaust valve, the secondary valve, and the secondary exhaust valve are located outside the flow controller.

12. The gas control system according to claim 11, wherein the flow rate controller further comprises an opening adjustment valve located upstream of the orifice in the gas supply channel.

13. The gas control system according to claim 9, further comprising a mounting member that integrally connects the orifice, the primary valve, the primary exhaust valve, the secondary valve, and the secondary exhaust valve.

14. The gas control system according to claim 9, wherein the flow rate of the gas supplied into the processing chamber is 0.1 sccm to 10 sccm.

15. The control unit, A deposition process in which a deposit is formed on a substrate introduced inside the processing chamber, The control is executed to repeatedly alternate between an etching process for etching the aforementioned substrate and a process for etching the substrate. The deposition process and the etching process each include a step of supplying gas into the processing chamber and a step of exhausting the inside of the gas supply channel, The gas control system according to claim 9, wherein the processing time for one cycle including the deposition process and the etching process is 1 to 10 seconds.

16. A gas control method using a gas control system, The gas control system is Multiple gas supply channels configured to independently supply gas to the processing chamber, An orifice is placed in each of the multiple gas supply channels, A primary valve located upstream of the orifice in the gas supply passage, A primary gas exhaust passage that branches off between the orifice and the primary valve in the gas supply passage and is connected to the primary exhaust mechanism, A primary exhaust valve is arranged in the primary gas exhaust passage, A secondary valve located downstream of the orifice in the gas supply passage, A secondary gas exhaust passage that branches off between the orifice and the secondary valve in the gas supply passage and is connected to the secondary exhaust mechanism, It has a secondary exhaust valve arranged in the secondary gas exhaust passage, (A) A step of opening the primary valve and the secondary valve of a first group of gas supply passages, in which at least one is selected from a plurality of gas supply passages, and closing the primary exhaust valve and the secondary exhaust valve of the first group of gas supply passages, and the primary valve, the secondary valve, the primary exhaust valve and the secondary exhaust valve of the other gas supply passages, (B) After closing the primary valve and the secondary valve in the first gas supply channel group, the primary exhaust valve and the secondary exhaust valve of the first gas supply channel group are opened. (C) After closing the primary exhaust valve and the secondary exhaust valve in the first gas supply flow path group, the primary valve and the secondary valve of the second gas supply flow path group, which is selected from the other gas supply flow paths, (D) A gas control method comprising the step of closing the primary valve and the secondary valve in the second gas supply channel group, and then opening the primary exhaust valve and the secondary exhaust valve in the second gas supply channel group.

17. The gas control method according to claim 16, comprising repeatedly and alternately executing a first process including step (A) and step (B), and a second process including step (C) and step (D).

18. A gas control system that controls the supply of gas into a processing chamber, A gas supply channel configured to supply gas to the processing chamber, An orifice is placed in the aforementioned gas supply channel, A flow control valve is positioned upstream of the orifice in the gas supply channel, A primary valve located upstream of the flow control valve in the gas supply channel, A secondary valve located downstream of the orifice in the gas supply passage, A secondary gas exhaust passage that branches off between the orifice and the secondary valve in the gas supply passage and is connected to the secondary exhaust mechanism, A secondary exhaust valve is arranged in the secondary gas exhaust passage, The system includes a control unit that independently controls the opening degree of the flow control valve, the primary valve, the secondary valve, and the secondary exhaust valve, The control unit, A step of supplying gas into the processing chamber by opening the flow control valve, the primary valve, and the secondary valve, and closing the secondary exhaust valve, A control system that alternately and repeatedly performs the following steps: closing the flow control valve, the primary valve, and the secondary valve, and opening the secondary exhaust valve to exhaust the inside of the gas supply passage; A gas control system that, in the process of supplying the gas, performs the control of opening the flow control valve and the primary valve prior to the secondary valve, filling the downstream side of the orifice with gas, and then opening the secondary valve.

19. The gas control system according to claim 18, wherein the control unit, in the process of supplying the gas, opens the secondary valve after the pressure downstream of the orifice has been raised to a predetermined reference pressure.

20. The gas control system according to claim 19, wherein the reference pressure is 80% or more and 120% or less of the pressure downstream of the secondary valve.