Plasma processing system and gas supplying method

Abstract

To appropriately supply gas to a chamber from two or more gas lines.SOLUTION: A plasma processing system comprises: a chamber; two or more gas lines for supplying gas to the chamber; a chamber sensor that detects that the gas reaches a defined amount; and a control device. Each of the gas lines comprises: a flow rate controller that controls a flow rate of the gas; an opening / closing valve that opens or closes a flow of the gas; and a valve driving unit. The control device, in each of the gas lines, executes controls that include the steps of: (a) actuating an opening / closing valve driving unit based on first opening / closing control information set to actuate the opening / closing valve driving unit at a first actuation time so that the gas in the chamber reaches the defined amount at a set time, and of supplying the gas to the chamber; (b) acquiring an actual measurement time, which is the time when the gas in the chamber reaches the defined amount; and (c) setting second opening / closing control information to include a second actuation time obtained by correcting the first actuation time by a difference between the set time and the actual measurement time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a plasma processing system and a gas delivery method. [Background technology]

[0002] Patent Document 1 describes a gas supply system in which gas is supplied to a chamber by controlling the flow rate of the gas through a plurality of gas lines using a flow rate control unit provided in each gas line. Each flow rate control unit has a primary valve, a flow rate controller, and a secondary valve in the gas line, and is connected to an exhaust device upstream of the flow rate controller. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-011055 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed herein appropriately supplies gas to a chamber from two or more gas lines. [Means for solving the problem]

[0005] One aspect of the present disclosure provides a plasma processing system including a chamber, two or more gas lines supplying gas to the chamber, a chamber sensor detecting when at least the gas in the chamber has reached a specified amount, and a control device, wherein each of the gas lines includes a flow rate controller for controlling a flow rate of the gas, an on-off valve that opens or closes the flow of the gas to the flow rate controller, and a valve driver that drives the on-off valve to open or close, and the control device performs control for each of the gas lines, including: (a) operating the on-off valve driver based on first on-off control information set to operate the on-off valve driver at a first operation time so that the gas in the chamber reaches the specified amount at a set time, thereby supplying the gas to the chamber; (b) acquiring an actual measurement time that is the time when the gas in the chamber has reached the specified amount; and (c) setting second on-off control information to include a second operation time obtained by correcting the first operation time based on a difference between the set time and the actual measurement time. [Effects of the Invention]

[0006] According to the present disclosure, gas is appropriately supplied to the chamber from two or more gas lines. It is possible. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram illustrating an outline of a configuration example of a plasma processing system; [Figure 2] FIG. 2 is an explanatory diagram illustrating an outline of a configuration example of a flow rate controller. [Figure 3] 1 is a flowchart showing an outline of a configuration example of a gas supply method. [Figure 4] 10 is a sequence chart showing an outline of an example of a state of a gas supply unit in a gas supply method. [Figure 5] 10 is a sequence chart showing an outline of another example state of the gas supply unit in the gas supply method. [Figure 6] FIG. 10 is an explanatory diagram illustrating an example of response time reduction control related to flow rate control. [Figure 7] 1A and 1B are explanatory diagrams for explaining an outline of a configuration example of a gas supply method and an example of an effect thereof; DETAILED DESCRIPTION OF THE INVENTION

[0008] In the manufacturing process of semiconductor devices, a processing module containing semiconductor wafers (hereinafter referred to as "substrates") is decompressed and various processing steps are performed on the substrates. The multiple processing steps include a step of supplying two or more gases to a chamber.

[0009] High-speed, precise gas control is required when switching gases to be supplied to a chamber at high speed, or when supplying gases in synchronization with RF signals, pressure, etc. Patent Document 1 discloses a gas supply system in which a flow rate control unit is provided for each of multiple gas lines and connected to an exhaust device upstream of the flow rate controller. Patent Document 1 discloses that when changing the gas supplied from the gas supply system to a processing device, the gas remaining in the gas line upstream of the orifice inside the flow rate control unit is rapidly exhausted, thereby rapidly replacing the gas in the flow path of the gas supply system.

[0010] However, the inventors of the present invention have conducted extensive research and discovered the following. Specifically, when flow control units are installed across multiple gas lines, as in Patent Document 1, and each unit controls the opening and closing of gas flow or the flow rate, there may be an error between the time when an instruction is received from the controller and the actual time when the gas reaches the chamber where the substrate is processed. Specifically, for example, because the control response characteristics of the flow controllers differ depending on the gas type, even if the controller simultaneously operates the flow controllers for multiple gas lines, the timing at which each gas reaches the chamber may differ for each gas type. Furthermore, when an opening and closing valve is mechanically controlled by air drive using a solenoid valve, the opening and closing operation of the valve may be delayed due to differences in the length (volume) of the air tube related to the air drive for each gas line. Patent Document 1 does not take into account delays in response to instructions from multiple flow controllers or differences in the timing of flow control due to the characteristics of each gas type.

[0011] Therefore, the technology according to the present disclosure appropriately supplies gas to the chamber from two or more gas lines.

[0012] Hereinafter, the configuration of the substrate processing apparatus according to this embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0013] <Plasma processing system>

[0014] 1 is a diagram illustrating an example of the configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a central control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber (hereinafter referred to as chamber 10), a substrate support unit 11, a plasma generation unit 12, and a gas supply unit 20.

[0015] The chamber 10 has a plasma processing space. The chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20, and the gas exhaust port is connected to an exhaust unit (not shown).

[0016] The substrate support 11 is disposed in the plasma processing space 10s and has a substrate support surface for supporting a substrate.

[0017] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma generating unit 12 includes a power supply or electrodes (not shown) for generating plasma. The plasma generated 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 generating unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0018] The exhaust unit may be connected to a gas exhaust port provided at the bottom of the chamber 10, for example. The exhaust unit may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0019] The central controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described in this disclosure. The central controller 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the central controller 2 may be included in the plasma processing apparatus 1. The central controller 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The central controller 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0020] <Gas supply section>

[0021] The gas supply unit 20 includes two or more gas lines, and in this embodiment includes a first gas line 41 and a second gas line 42. Hereinafter, the first gas line 41 and the second gas line 42 may be collectively referred to simply as "gas lines." In one embodiment, the gas supply unit 20 includes one or more other gas lines.

[0022] The first gas line 41 includes a first flow path 50 (indicated by a thick line in FIG. 1 ) through which a gas flows, a first gas source GS11 connected via a first on-off valve V11 upstream of the first flow path 50, a second gas source GS12 connected via a second on-off valve V12, a first flow rate controller 55 provided on the first flow path 50 downstream of the first on-off valve V11 and the second on-off valve V12, and a third on-off valve V13 provided downstream of the first flow rate controller 55. The first gas line 41 is connected to a gas supply port 11 of the chamber 10 downstream of the third on-off valve V13. In one embodiment, one or more other gas sources are connected to the first flow path 50 via corresponding on-off valves.

[0023] Similar to the first gas line 41, the second gas line 42 includes a second flow path 60 (shown by a thick line in FIG. 1 ) through which a gas flows, a third gas source GS21 connected via a fourth on-off valve V21 upstream of the second flow path 60, a fourth gas source GS22 connected via a fifth on-off valve V22, a second flow rate controller 65 provided on the second flow path 60 downstream of the fourth on-off valve V21 and the fifth on-off valve V22, and a sixth on-off valve V23 provided downstream of the second flow rate controller 65. The second gas line 42 is connected to a gas supply port 11 of the chamber 10 downstream of the sixth on-off valve V23. In one embodiment, one or more other gas sources are connected to the second flow path 60 via corresponding on-off valves.

[0024] The first to sixth on-off valves V11 to V23 according to this embodiment are air-operated valves. Solenoid valves SL11 to SL23 and air tubes AT11 to AT23 are provided for the first to sixth on-off valves V11 to V23, respectively, as valve drivers. By controlling the on / off operation of the air supply from the solenoid valves SL11 to SL23 via the air tubes AT11 to AT23, the opening and closing of the first to sixth on-off valves V11 to V23 can be controlled. The operation of the solenoid valves SL11 to SL23 is controlled by a gas control unit 120, which will be described later.

[0025] FIG. 2 is an explanatory diagram schematically illustrating an example of the configuration of the first flow rate controller 55 according to this embodiment. While FIG. 2 and the following description will illustrate the first flow rate controller 55 as a representative example, the same applies to the second flow rate controller 65. The first flow rate controller 55 according to this embodiment is a pressure-controlled flow rate controller and includes a control valve 101, a control valve driver 102, a pressure sensor 103, an orifice 104, and a flow rate controller control circuit 105. The control valve driver 102 drives the control valve 101 to open and close to a desired opening degree. The control valve driver 102 is controlled by a calculation unit 122 in a gas control unit 120 (described later) via the flow rate controller control circuit 105. The pressure sensor 103 detects the pressure in the first flow path 50, and the pressure value is transmitted to the calculation unit 122 (described later). The first and second flow rate controllers 55 and 65 are not limited to the above example configuration and may be mass flow controllers, for example.

[0026] Returning to FIG. 1 , the gas supply unit 20 includes a chamber sensor 110. The chamber sensor 110 according to this embodiment includes, for example, an optical emission spectrometer (OES) optically connected to the sidewall of the chamber 10. The OES serving as the chamber sensor 110 detects the emission spectrum of plasma light emitted by each gas species supplied to the plasma processing space in the chamber 10, and acquires the amount of each gas species present. The detected amount is, for example, the flow rate of the gas in the plasma processing space. The chamber sensor 110 according to one embodiment includes a capacitance manometer. The capacitance manometer serving as the chamber sensor 110 detects a pressure value representing the amount of gas present supplied to the plasma processing space 10s. The amount of each gas species acquired by the chamber sensor 110 is transmitted to the gas control unit 120, which will be described later.

[0027] The gas supply unit 20 also includes a gas control unit 120, one for each of the first gas line 41 and the second gas line 42. The gas control unit 120 includes a communication unit 121, a calculation unit 122, and an on-off valve control circuit 123.

[0028] The communication unit 121 exchanges signals with the outside, including the central control unit 2, and exchanges signals between each component of the gas control unit 120 and each component of the gas supply unit 20. The communication unit 121 receives, for example, a signal including information such as the type of gas to be supplied to the chamber 10 and its flow rate, transmitted from the central control unit 2, and passes this information to the calculation unit 122. The communication unit 121 also receives, for example, a signal including information on the amount of each gas type obtained by the chamber sensor 110, and passes this information to the calculation unit 122. The dotted arrows in FIG. 1 represent wired or wireless electrical signals, and the direction of the arrow indicates the direction of signal transmission.

[0029] The calculation unit 122 processes information received from the communication unit 121 and sets or corrects control information (described later). It also executes feedback control of the flow rates in the first and second flow rate controllers 55 and 65. In the feedback control, the calculation unit 122 adjusts the opening of the control valve 101 based on a set flow rate value included in the control information (described later), an actual flow rate value calculated based on the pressure values in the first and second flow paths 50 and 60 detected by the pressure sensor 103, and the current opening of the control valve 101, so that the actual flow rate value approaches the set flow rate value. The opening of the control valve 101 is adjusted by controlling the control valve driver 102 via the flow rate controller control circuit 105. In this case, the calculation unit 122 calculates the actual flow rate value based on the pressure value and calculates the difference between the actual flow rate value and the set flow rate value. It also sets control information for the control valve driver 102 based on the difference. In one embodiment, the calculation unit 122 communicates directly with the flow rate controller control circuits 105 in the first and second flow rate controllers 55 and 65 without going through the communication unit 121 .

[0030] The calculation unit 122 also controls the opening and closing of the solenoid valves SL11 to SL23 via the opening and closing valve control circuit 123 based on control information, which will be described later.

[0031] <Gas supply method> A gas supply method using the gas supply unit 20 will be described below. Fig. 3 is a flowchart outlining an example of the configuration of the gas supply method. Figs. 4 and 5 are sequence charts outlining the control or operation of each component of the gas supply unit 20 in each step, or the state of the gas pressure or flow rate.

[0032] In step ST11, the gas control unit 120 operates the solenoid valves SL11 to SL23 via the on-off valve control circuit 123 based on first on-off control information. The first on-off control information includes information on a first operation time t11 predetermined for each of the solenoid valves SL11 to SL23. "Operating the solenoid valves SL11 to SL23" includes opening the solenoid valves SL11 to SL23 at the first operation time t11 in response to a signal from the on-off valve control circuit 123 and supplying air to the first to sixth on-off valves V11 to V23 via the air tubes AT11 to AT23. In one embodiment, the first operation time t11 is predetermined for each of the solenoid valves SL11 to SL23 based on the volume of each of the air tubes AT11 to AT23, the air supply pressure, etc. In one embodiment, the first operation time t11 is determined for each of the solenoid valves SL11 to SL23, for example.

[0033] In step ST12, the first to sixth on-off valves V11 to V23 are opened as a result of air being supplied from the solenoid valves SL11 to SL23 to the first to sixth on-off valves V11 to V23 via the air tubes AT11 to AT23 in step ST11. At the first operation time t11, for example, the first to third on-off valves V11 to V13 and the fourth to sixth on-off valves V21 to V23 are opened approximately simultaneously.

[0034] In step ST13, as a result of the first to sixth opening / closing valves V11 to V23 being opened in step ST12, gas supplied from the first and second gas sources GS11 and GS12 starts to flow through the first flow path 50, and gas supplied from the third and fourth gas sources GS21 and GS22 starts to flow through the second flow path 60.

[0035] In step ST14, the gas control unit 120 starts controlling the first and second flow rate controllers 55, 65 via the flow rate controller control circuit 105 based on the first flow rate control information. In one embodiment, the calculation unit 122 feedback-controls the apertures of the control valves 101 in the first and second flow rate controllers 55, 65 so that the actual flow rate values of the gas in the first and second flow paths 50, 60 approach the set flow rate values. In this case, the first flow rate control information includes information on the set flow rate values in the first and second flow paths 50, 60 that are subject to feedback control and information on the aperture of the control valve 101. The first flow rate control information also includes information on a first start time t12, which is the time at which feedback control of the control valve 101 is to start, predetermined for each of the first and second flow rate controllers 55, 65. In one embodiment, "starting control of the first and second flow rate controllers 55, 65" includes activating the control valve driver 102 at the first start time t12 in response to a signal from the calculation unit 122. In one embodiment, the first start time t12 is the time when the gas pressure reaches a predetermined value at the pressure sensor 103. In this case, the predetermined value at the pressure sensor 103 is set to a value such that the gas reaches a specified amount in the plasma processing space of the chamber 10 at the set time T1, taking into account the response time after the start of feedback control.

[0036] In step ST15, the amount of gas present in the plasma processing space of the chamber 10 is detected by the chamber sensor 110. In this embodiment, the amount of gas present is detected as a flow rate. In the example shown in FIG. 4, the gas supplied from the first gas line 41 in the plasma processing space (dotted line in FIG. 4) is detected to have reached a specified flow rate at actual measurement time T2a. Also, the gas supplied from the second gas line 42 (dashed line in FIG. 4) is detected to have reached a specified flow rate at actual measurement time T2b.

[0037] Here, the first on / off control information is control information set so that the gas in the plasma processing space of the chamber 10 reaches a predetermined amount at a set time T1. In this embodiment, the set time T1 is the same time common to the first gas line 41 and the second gas line 42. That is, the gas supplied from both gas lines is scheduled to reach a predetermined amount in the plasma processing space at the set time T1 simultaneously. In one embodiment, the set time T1 may be different for each gas line. In this case, the first on / off control information is preset to operate the solenoid valves SL11 to SL23 so that the gas supplied from the first gas line 41 reaches a predetermined amount in the plasma processing space of the chamber 10 at one set time T1, and is also preset to operate the solenoid valves SL11 to SL23 so that the gas supplied from the second gas line 42 reaches a predetermined amount in the plasma processing space of the chamber 10 at another set time T1.

[0038] The first flow rate control information is control information that is preset to control the flow rate of the gas so that it reaches a specified amount in the plasma processing space of the chamber 10 at a set time T1. In one embodiment, when the set time T1 is set to a different time for each gas line, the first flow rate control information is preset to control the flow rate in the first flow rate controller 55 so that the gas supplied from the first gas line 41 in the plasma processing space of the chamber 10 reaches a specified amount at one set time T1, and is also preset to control the flow rate in the second flow rate controller 65 so that the gas supplied from the second gas line 42 in the plasma processing space of the chamber 10 reaches a specified amount at another set time T1.

[0039] As a result of extensive research, the present inventors have found that even when control is performed based on the preset first on / off control information and first flow rate control information as described above, the time at which the gas in the plasma processing space reaches a specified amount may differ from the set time T1. That is, as shown in Fig. 4, the set time T1, which is the time at which the gas (solid line in Fig. 4) expected in the first on / off control information and the first flow rate control information reaches the specified amount, differs from the actual times T2a and T2b, which are the times at which the gas (dotted or dashed line) supplied from the first and second gas lines 41 and 42 actually reaches the specified amount. This is thought to be due to the fact that gas species with different response characteristics to flow rate control flow in the first gas line 41 and the second gas line 42, and the different piping lengths (volumes) of the first and second flow paths 50 and 60.

[0040] In step ST16, the calculation unit 122 acquires information on the measured times T2a and T2b, and calculates the differences between the set time T1 and the measured times T2a and T2b, respectively.

[0041] In step ST17, at least second opening / closing control information is set based on the difference calculated in step ST16. The second opening / closing control information is set in the calculation unit 122 by correcting the first operation time t11 of the solenoid valves SL11 to SL23 in the first opening / closing control information based on the difference. In one embodiment, second flow rate control information is set. The second flow rate control information is set in the calculation unit 122 by correcting the first start time t12 of the flow rate controller in the first flow rate control information based on the difference between the set time and the actual measured time.

[0042] Specifically, the setting of the second opening / closing control information in step ST17 is performed as follows. The calculation unit 122 corrects the first operation time t11 of the solenoid valves SL11 to SL23 included in the first opening / closing control information based on the difference between the set time T1 and the actual times T2a and T2b, and sets the second operation time t21. In the example shown in FIG. 4, the actual time T2a is earlier than the set time T1, and the actual time T2b is later than the set time T1. In this case, the second operation time t21 of the solenoid valves SL11 to SL13 in the first gas line 41 is set to be later than the first operation time t11. Furthermore, the second operation time t21 of the solenoid valves SL21 to SL23 in the second gas line 42 is set to be earlier than the first operation time t11. The second opening / closing control information is set to include the control information for the second operation time t21 set in this way. By controlling the solenoid valves SL11 to SL23 via the on-off valve control circuit 123 based on the second on-off control information, the solenoid valves SL11 to SL23 can be opened at the corrected time T3 so that the gas reaches a specified amount in the plasma processing space of the chamber 10.

[0043] In other words, the second opening / closing control information is control information set in step ST17 to operate the solenoid valves SL11-SL23 at the second operation time t21 so that the gas in the plasma processing space of the chamber 10 reaches a predetermined amount at the corrected time T3. In this embodiment, the corrected time T3 is the same time common to the first gas line 41 and the second gas line 42. That is, the gas supplied from both gas lines is scheduled to reach a predetermined amount in the plasma processing space at the corrected time T3 simultaneously. In one embodiment, the corrected time T3 may be different for each gas line. In this case, the first opening / closing control information is set to operate the solenoid valves SL11-SL23 so that the gas supplied from the first gas line 41 reaches a predetermined amount in the plasma processing space of the chamber 10 at one corrected time T3, and is also set to operate the solenoid valves SL11-SL23 so that the gas supplied from the second gas line 42 reaches a predetermined amount in the plasma processing space of the chamber 10 at another corrected time T3. In one embodiment, the corrected time T3 is the same as the set time T1.

[0044] Specifically, the setting of the second flow rate control information in step ST17 is performed as follows. The calculation unit 122 corrects the first start time t12 of the feedback control of the control valve 101 included in the first flow rate control information based on the difference between the set time T1 and the actual measurement times T2a and T2b, and sets the second start time t22. In the example shown in FIG. 4, the actual measurement time T2a is earlier than the set time T1, and the actual measurement time T2b is later than the set time T1. In this case, the second start time t22 of the feedback control of the control valve 101 in the first gas line 41 is corrected to be later than the first start time t12. Furthermore, the second start time t22 of the feedback control of the control valve 101 in the second gas line 42 is corrected to be earlier than the first start time t12. The second flow rate control information is set to include the control information for the second start time t22 set in this manner. The calculation unit 122 performs feedback control of the control valve 101 based on the second flow control information, thereby controlling the flow rates in the first and second flow controllers 55, 65 so that the gas reaches a specified amount in the plasma processing space of the chamber 10 at the corrected time T3.

[0045] In other words, the second flow rate control information is control information set in step ST17 to control the flow rates in the first and second flow rate controllers 55, 65 so that the gas reaches a specified amount in the plasma processing space of the chamber 10 at the corrected time T3. In one embodiment, when the corrected time T3 is set to a different time for each gas line, the first flow rate control information is set to control the flow rate in the first flow rate controller 55 so that the gas supplied from the first gas line 41 reaches a specified amount in the plasma processing space of the chamber 10 at one corrected time T3, and is set to control the flow rate in the second flow rate controller 65 so that the gas supplied from the second gas line 42 reaches a specified amount in the plasma processing space of the chamber 10 at another corrected time T3. In one embodiment, the corrected time T3 is the same as the set time T1.

[0046] In one embodiment, the second flow rate control information includes control to shorten the response time related to the flow rate control. Figure 6 is an explanatory diagram showing an example of control to shorten the response time related to the flow rate control. In each of graphs (A) to (C), the vertical axis represents the flow rate calculated from the gas pressure measured by the pressure sensor 103, and the horizontal axis represents time. (A) of Figure 6 shows normal control related to the flow rate control, and the response time in this case is Δt1.

[0047] 6B shows an example of control to shorten the response time related to flow rate control. In this case, the opening of control valve 101 is increased at the start of feedback control compared to the example in (A), and the slope of the rise in gas pressure is increased, thereby shortening the response time until the specified flow rate is reached to Δt2.

[0048] 6C shows another example of time-saving control. In this case, the opening of the control valve 101 is increased at the start of feedback control compared to the case of (A), and the slope of the gas pressure rise is increased. The flow rate is also allowed to rise above the specified flow rate. After that, the opening of the control valve 101 is adjusted by feedback control to control the flow rate to reach the specified flow rate. The response time until the flow rate stabilizes at the specified flow rate is approximately the same as Δt1, but the response time until the flow rate exceeds the specified flow rate is shorter than Δt1. As a result, the response time until the gas reaches the specified amount in the plasma processing space can be shortened.

[0049] If the second flow control information includes control to shorten the response time related to the flow control, the second operation time t21 at which the solenoid valves SL11 to SL23 are operated in the second opening / closing control information may be delayed by the shortened response time.

[0050] After step ST17 is performed, the gas supply method ends. In one embodiment, steps ST11 to ST17 are recursively performed using the second opening / closing control information and second flow rate control information set in step ST17 instead of the first opening / closing control information and first flow rate control information. FIG. 5 is a sequence chart outlining the control or operation of each component of the gas supply unit 20 or the gas pressure or flow rate state in each step when steps ST11 to ST17 are performed using the second opening / closing control information and second flow rate control information. In the example shown in FIG. 5, the solenoid valves SL11 to SL23 are operated at second operation time t21 using the second opening / closing control information, and feedback control of the flow rates is started in the first and second flow rate controllers 55 and 65 at second start time t22 using the second flow rate control information. As a result, the gas flow rate in the plasma processing space of chamber 10 detected by chamber sensor 110 actually reaches the specified flow rate at correction time T3. That is, the gases supplied from the first gas line 41 and the second gas line 42 simultaneously reach the specified flow rates in the plasma processing space of the chamber 10 at the corrected time T3.

[0051] 7 is an explanatory diagram illustrating an example of the outline of the configuration and effects of the gas supply method according to this embodiment. The patterns (A) to (D) shown in FIG. 7 show the response times of the first control interval C1 and the second control interval C2 from the activation time of the solenoid valves SL11 to SL23 (the first activation time t11 or the second activation time t21) to the time when the gas in the plasma processing space is expected to reach a specified amount or when it is actually measured that the gas has reached the specified amount (the set time T1, the actual measurement time T2a, T2b, or the corrected time T3).

[0052] 7 is a control section for controlling the gas pressure upstream of the orifice 104. The response time in the first control section C1 is from the activation time of the solenoid valves SL11 to SL23 to the time when the gas pressure reaches a predetermined value at the pressure sensor 103. The response time in the control section C1 is significantly affected by the activation time of the solenoid valves SL11 to SL23.

[0053] 7 is a control section for the gas pressure downstream of the orifice 104. The response time in the second control section C2 is from the time when the gas pressure reaches a predetermined value at the pressure sensor 103 to the time when the gas is predicted to reach a predetermined amount in the plasma processing space or when it is actually measured that the gas has reached the predetermined amount. The response time in the second control section C2 is significantly affected by the start time of the feedback control of the control valve 101 in the flow rate controllers 50 and 60.

[0054] 7 shows the expected response time when control is performed using the first opening / closing control information and the first flow rate control information that are set so that the gas reaches a specified amount in the plasma processing space of the chamber 10 at the set time T1. In other words, in the pattern (A), the solenoid valves SL11-SL23 are opened at the operation time t11, and the control valve driver 102 starts operating at the first start time t12. As a result, the gas is expected to reach a specified amount in the plasma processing space of the chamber 10 at the set time T1.

[0055] 7 shows the response time measured when control is performed using the first opening / closing control information and the first flow rate control information. In other words, in pattern (B), the solenoid valves SL11-SL23 are opened at the first operation time t11, and the control valve driver 102 is then activated when the gas pressure reaches a predetermined value measured by the pressure sensor 103. As a result, the gas in the plasma processing space of the chamber 10 reaches a predetermined amount at the actual measurement time T2b, which is later than the set time T1, for example (see ST15 in FIG. 3).

[0056] 7 shows the response time measured when control is performed using the second opening / closing control information and the second flow rate control information. In other words, in pattern (C), the solenoid valves SL11-SL23 are opened at the second operation time t21, and the control valve driver 102 is then activated at the time when the gas pressure measured by the pressure sensor 103 reaches a predetermined value. As a result, the gas in the plasma processing space of the chamber 10 reaches a predetermined amount at the corrected time T3 (see ST17 in FIG. 3).

[0057] Pattern (D) in FIG. 7 shows the response time measured when control is performed using the second opening / closing control information and the second flow control information. The second flow control information in pattern (D) further includes a control for shortening the response time related to the flow control. In pattern (D), the solenoid valves SL11 to SL23 are opened at the second actuation time t21, and then the control valve driver 102 starts operating at the time when the gas pressure measured by the pressure sensor 103 reaches a predetermined value. At this time, the above-described response time shortening control (see (B) and (C) in FIG. 6) is further executed. Furthermore, the second actuation time t21 at which the solenoid valves SL11 to SL23 are actuated is delayed by the response time shortened by the shortening control. As a result, the second actuation time t21 at which the solenoid valves SL11 to SL23 are actuated can be made approximately the same as the first actuation time t21. As a result, the gas reaches a specified amount in the plasma processing space of the chamber 10 at the corrected time T3 (see ST17 in FIG. 3), while the overall response time of the pattern (D) is made approximately the same as the response time expected in the pattern (A).

[0058] In steps ST11 to ST13 according to one embodiment, the gas control unit 120 detects a control error in the gas pressure in the first and second flow paths 50 and 60 using the pressure sensors 103 in the first and second flow paths 55 and 65. The control error includes a case where, when the gas pressure in the first and second flow paths 50 and 60 is controlled to reach a set value at a certain set time, the time at which the gas pressure reaches the set value differs from the set time. The control error occurs, for example, due to differences in the lengths of the air tubes AT11 to AT23 or the piping lengths of the first and second flow paths 50 and 60, or due to differences in the pressure that can be controlled by the flow path controller depending on the gas type. For example, if the time at which the gas pressure detected by the pressure sensor 103 in the first flow path controller 55 reaches a specified value differs from the time at which the gas pressure detected by the pressure sensor 103 in the second flow path controller 65 reaches the specified value, the occurrence of a control error is detected. In this case, in step ST17, the calculation unit 122 sets the second operation time t21 corrected so that the control error does not occur.

[0059] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0060] For example, in this embodiment, the control when starting the supply of gas to the chamber 10 has been described, but by executing the same control as in the above embodiment, it is possible to execute the control when ending the supply of gas.

[0061] Furthermore, for example, although the flow rate controller control circuit 105 is provided in each of the flow rate controllers 55 and 65, similar to the on-off valve control circuit 123, one flow rate controller control circuit 105 may be provided in the gas control unit 120 for multiple flow rate controllers. In this case, for example, the calculation unit 122 may correct the flow rate control information for each flow rate controller based on calibration values relating to individual differences of the multiple flow rate controllers that have been acquired and recorded in advance, and transfer the corrected flow rate control information to the flow rate controller control circuit 105. This makes it possible to respond to the flow rate control information after removing the influence of individual differences in each flow rate controller.

[0062] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects. [Explanation of symbols]

[0063] 1. Plasma processing equipment 10 Chambers 41 First Gas Line 42 Second Gas Line 55 First flow controller 65 Second flow controller 110 Chamber Sensor 120 Gas Control Unit V11~V23 1st~6th opening and closing valves SL11~SL23 solenoid valves T1 Set time T2a and T2b measurement times t11 First operation time t21 Second operating time

Claims

1. a chamber; two or more gas lines supplying gas to the chamber; a chamber sensor for detecting when at least the gas reaches a predetermined amount in the chamber; a control device; each of the gas lines includes a flow rate controller for controlling a flow rate of the gas; an on-off valve for opening or closing the flow of the gas to the flow rate controller; and a valve driver for driving the on-off valve to open or close; The control device controls each of the gas lines. (a) operating the on-off valve driver based on first on-off control information set to operate the on-off valve driver at a first operation time so that the gas in the chamber reaches the specified amount at a set time, and supplying the gas to the chamber; (b) acquiring an actual time when the gas reaches the specified amount in the chamber; (c) setting the second opening / closing control information to include a second operation time obtained by correcting the first operation time based on a difference between the set time and the actual measured time; a plasma processing system;

2. the step (a) includes controlling the flow rate controller based on first flow rate control information set to start control of the flow rate controller at a first start time so that the gas in the chamber reaches the specified amount at the set time; the step (c) includes setting the second flow rate control information to include a second start time obtained by correcting the first start time based on a difference between the set time and the actual measured time; 10. The plasma processing system of claim 1.

3. the control device includes a control unit provided for two or more of the gas lines, The control unit a calculation unit that executes control including at least one of setting the second on-off control information for each of the on-off valve driving units and setting the second flow rate control information for each of the flow rate controllers; 3. The plasma processing system according to claim 2, further comprising: an on-off valve control circuit for controlling operation of the on-off valve driver.

4. the flow rate controller includes a flow rate controller sensor unit, a control valve with an adjustable opening, a control valve drive unit that drives the opening and closing of the control valve, and a flow rate controller control circuit; the flow rate controller control circuit is configured to be able to transmit information acquired by the flow rate controller sensor unit to a calculation unit, and to operate a control valve driving unit by a control signal transmitted from the calculation unit; The calculation unit Calculating an actual measured flow rate value based on information acquired by the flow rate controller sensor unit; 4. The plasma processing system of claim 3, wherein the control includes: feedback controlling the control valve driving unit based on the actual flow rate value and a set flow rate value included in the first flow rate control information or the second flow rate control information so as to bring the actual flow rate value closer to the set flow rate value, for two or more of the flow rate controllers.

5. 1. A method of delivering gas using a plasma processing system, comprising: the plasma processing system includes: a chamber; two or more gas lines supplying gas to the chamber; a chamber sensor that detects when at least the gas in the chamber reaches a predetermined amount; each of the gas lines includes a flow rate controller for controlling a flow rate of the gas; an on-off valve for opening or closing the flow of the gas to the flow rate controller; and a valve driver for driving the on-off valve to open or close; The gas supply method includes: (a) operating the on-off valve driver based on first on-off control information set to operate the on-off valve driver at a first operation time so that the gas in the chamber reaches the specified amount at a set time, and supplying the gas to the chamber; (b) acquiring an actual time when the gas reaches the specified amount in the chamber; (c) setting the second opening / closing control information to include a second operation time obtained by correcting the first operation time based on a difference between the set time and the actual measured time; in each of the gas lines.

6. the step (a) includes controlling the flow rate controller based on first flow rate control information set to start control of the flow rate controller at a first start time so that the gas in the chamber reaches the specified amount at the set time; the step (c) includes setting the second flow rate control information to include a second start time obtained by correcting the first start time based on a difference between the set time and the actual measured time; The gas supply method according to claim 5 .

7. the flow rate controller includes a flow rate controller sensor unit, a control valve with an adjustable opening, a control valve drive unit that drives the opening and closing of the control valve, and a flow rate controller control circuit; Calculating an actual measured flow rate value based on information acquired by the flow rate controller sensor unit; and feedback-controlling the control valve driving unit based on the actual flow rate value and a set flow rate value included in the first flow rate control information or the second flow rate control information so as to bring the actual flow rate value closer to the set flow rate value, for two or more of the flow rate controllers.

Images