Adjustment method and plasma processing system

Abstract

A method for adjusting a plasma processing chamber capable of supplying a tungsten-containing gas to the inside and performing plasma processing on a substrate housed in the inside, the method comprising: (A) a step for removing moisture from the inside of the plasma processing chamber by using a gas that does not contain the tungsten-containing gas; and (B), after the step (A), adjusting the internal environment of the plasma processing chamber by generating plasma while supplying a gas containing the tungsten-containing gas.

Description

Technical Field

[0001] This disclosure relates to conditioning methods and plasma processing systems. Background Technology

[0002] Patent Document 1 discloses a plasma processing system that forms a protective film on a mask by housing a substrate having a mask film on the upper part of a pattern in a plasma processing chamber and supplying tungsten-containing gas into the plasma processing chamber.

[0003] In such plasma processing systems, during maintenance procedures to remove films adhering to components within the plasma processing chamber, for example, the processing container may be opened to replace consumables or to clean the interior of the processing container. When the processing container is opened, moisture from the atmosphere can be adsorbed into the interior of the processing container or its components. In this case, moisture may remain inside the processing container after maintenance. Therefore, after maintenance, the plasma processing apparatus performs a process to remove the moisture adhering to the interior of the processing container or its components.

[0004] <Prior art documents> <Patent Documents> Patent Document 1: Japanese Patent Application Publication No. 2023-111329 Summary of the Invention <Problem to be solved by this invention> This disclosure provides a technique for stably supplying tungsten-containing gas for plasma processing after maintenance or device startup.

[0005] <Methods for solving problems> According to one aspect of this disclosure, a method for regulating a plasma processing chamber capable of supplying tungsten-containing gas to the interior and performing plasma treatment on a substrate housed therein is provided, comprising the following steps: (A) removing moisture from the plasma processing chamber using a gas that does not contain the tungsten-containing gas; and (B) after step (A), adjusting the internal environment of the plasma processing chamber by generating plasma while supplying the gas containing the tungsten-containing gas.

[0006] <The Effects of the Invention> According to one method, plasma processing with a tungsten-containing gas can be stably performed after maintenance or device startup. Attached Figure Description

[0007] Figure 1 This is a schematic diagram illustrating the plasma processing system involved in the embodiment.

[0008] Figure 2This is a schematic diagram illustrating an example of the reaction of WF gas with a component coated with moisture in a plasma processing chamber.

[0009] Figure 3 This is a flowchart illustrating the processing flow of the adjustment method involved in the implementation method.

[0010] Figure 4 (A) is a table illustrating the processing conditions for the moisture removal process. Figure 4 Table (B) shows the relationship between the number of cycles of dry cleaning and the intensity of hydrogen luminescence remaining in the plasma processing chamber.

[0011] Figure 5 (A) is a table illustrating the processing conditions for the air-drying process. Figure 5 Table (B) shows the relationship between the number of air-drying cycles and the etching rate of the silicon oxide film implemented in the plasma processing chamber 10.

[0012] Figure 6 This is a chart comparing the flow rates of WF gas with and without flow calibration procedures.

[0013] Figure 7 This is a time series diagram of the adjustment method involved in the implementation method. Detailed Implementation

[0014] Hereinafter, the mode for implementing this disclosure will be described with reference to the accompanying drawings. In the drawings, the same symbols are used to label the same components, and repeated descriptions are sometimes omitted.

[0015] Figure 1 This is a schematic diagram illustrating the plasma processing system involved in the embodiment. First, refer to... Figure 1 An example of the configuration of a plasma processing system will be described.

[0016] The plasma processing system includes a capacitively coupled plasma processing device 1 and a control unit 2. The capacitively coupled plasma processing device 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. Additionally, the plasma processing device 1 includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a spray head 13. The substrate support 11 is disposed within the plasma processing chamber 10. The spray head 13 is disposed above the substrate support 11. In one embodiment, the spray head 13 constitutes at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the spray head 13, the sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas outlet for discharging gas from the plasma processing space. The sidewall 10a is grounded. The spray head 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0017] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region (substrate support surface) 111a for supporting a substrate (wafer) W and an annular region (ring support surface) 111b for supporting the ring assembly 112. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 when viewed from above. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 in such a way that it surrounds the substrate W on the central region 111a of the main body portion 111. In one embodiment, the main body portion 111 includes a base and an electrostatic chuck. The base includes conductive members. The conductive members of the base function as a lower electrode. The electrostatic chuck is disposed on the base. The upper surface of the electrostatic chuck has the substrate support surface 111a. The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Furthermore, although not shown in the figure, the substrate support 11 may also include a temperature control module configured to adjust at least one of the electrostatic chuck, ring assembly 112, and substrate to a target temperature. The temperature control module may also include a heater, a heat transfer medium, a flow path, or a combination thereof. In the flow path, a heat transfer fluid such as brine or gas flows. Additionally, the substrate support 11 may include a heat transfer gas supply section configured to supply heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0018] The spray head 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The spray head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlets 13c. The process gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s through the gas diffusion chamber 13b and the plurality of gas inlets 13c. Furthermore, the spray head 13 includes a conductive member. The conductive member of the spray head 13 functions as an upper electrode. In addition to the spray head 13, the gas inlet may also include one or more side gas injectors (SGIs) installed in one or more openings formed in the sidewall 10a.

[0019] The gas supply unit 20 may also include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one type of processing gas from a corresponding gas source 21 to a spray head 13 via a corresponding flow controller 22. Each flow controller 22 may, for example, include a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may also include one or more flow modulation devices for modulating or pulsedizing the flow rate of the at least one type of processing gas.

[0020] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to the conductive members of the substrate support 11 and / or the conductive members of the spray head 13. As a result, plasma is 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 part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the conductive members of the substrate support 11, a bias potential can be generated on the substrate W, introducing ionic components from the formed plasma into the substrate W.

[0021] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to a conductive member of the substrate support 11 and / or a conductive member of the spray head 13 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 13MHz to 150MHz. In one embodiment, the first RF generation unit 31a may also be configured to generate multiple source RF signals with different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support 11 and / or the conductive member of the spray head 13. The second RF generation unit 31b is coupled to a conductive member of the substrate support 11 via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400kHz to 13.56MHz. In one embodiment, the second RF generation unit 31b may also be configured to generate multiple bias RF signals with different frequencies. The generated one or more bias RF signals are supplied to the conductive members of the substrate support unit 11. Furthermore, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0022] Furthermore, 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 generating unit 32a and a second DC generating unit 32b. In one embodiment, the first DC generating unit 32a is connected to a conductive member of the substrate support 11 and is configured to generate a first DC signal. The generated first bias DC signal is applied to the conductive member of the substrate support 11. In one embodiment, the first DC signal may also be applied to other electrodes, such as electrodes within an electrostatic chuck. In one embodiment, the second DC generating unit 32b is connected to a conductive member of the spray head 13 and is configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the spray head 13. In various embodiments, at least one of the first and second DC signals may be pulsed. Additionally, 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.

[0023] The exhaust system 40 can be connected, for example, to a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may also include a pressure regulating valve and a vacuum pump. The pressure regulating valve is used to adjust the pressure within the plasma processing space 10s. The vacuum pump may also include a turbomolecular pump, a dry pump, or a combination thereof.

[0024] The control unit 2 processes computer-executable commands that cause the plasma processing apparatus 1 to perform the various processes described herein. The control unit 2 can be configured to control various elements of the plasma processing apparatus 1 in a manner that executes the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may, for example, include a computer 2a. The computer 2a may, for example, include a processing unit (CPU) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 can be configured to perform various control actions based on programs stored in the storage unit 2a2. The storage unit 2a2 may also include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or combinations thereof. The communication interface 2a3 may also communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0025] The control unit 2 controls each component of the plasma processing apparatus 1 to perform plasma processing on the substrate W housed in the plasma processing chamber 10. The plasma processing system according to this embodiment performs plasma processing as follows: gas for forming a protective film to protect the mask film on the surface of the substrate W is supplied from the gas supply unit 20 into the plasma processing chamber 10, and RF power is supplied from the power supply 30 to the conductive components (substrate support 11, spray head 13). As a result, a protective film is formed on the mask film on the surface of the substrate W, and plasma etching is performed.

[0026] Specifically, the gas supply unit 20 supplies tungsten hexafluoride (WF6) gas (hereinafter, tungsten hexafluoride gas is also simply referred to as WF gas) as a tungsten-containing gas to form the protective film. Furthermore, the tungsten-containing gas is not limited to WF gas; for example, it can be chlorine-containing gases such as tungsten pentachloride (WCl5) gas or tungsten hexachloride (WCl6) gas. In addition to WF gas, the gas supply unit 20 may also include appropriate additive gases for supply, or supply additive gases at staggered timings. Examples of other additive gases include rare gases such as helium (He) or argon (Ar), oxygen-containing gases such as oxygen (O2) or ozone (O3), or inactive gases such as nitrogen (N2). The control unit 2 supplies the tungsten-containing gas as the main gas to the plasma processing space 10s based on the plasma processing conditions set in the process, and controls the generation of plasma. Thus, plasma etching can be performed while forming a tungsten-containing protective film on the mask film.

[0027] As described above, the plasma processing system according to the embodiment performs plasma processing while supplying tungsten-containing gas (WF gas). Because WF gas is heavier than other gases and has high viscosity, it tends to linger in confined spaces and is difficult to expel. Therefore, when maintaining a plasma processing system using tungsten-containing gas as the processing gas, the plasma processing chamber 10 is opened for cleaning of internal components and / or piping, and measures are taken to suppress WF gas retention. In this case, after maintenance, atmospheric moisture (H2O) is adsorbed and remains in components 100, etc., within the plasma processing chamber 10.

[0028] On the other hand, tungsten-containing gases also have the characteristic of readily reacting with moisture. Figure 2 This is a schematic diagram showing an example of the reaction of WF gas with a component 100 coated with moisture within the plasma processing chamber 10. The WF gas reacts with the moisture as shown in the following chemical reaction formulas (1) and (2).

[0029] WF6+3H2O → WOF4+2HF……(1) WF6+3H2O → WO3+6HF……(2) That is, when WF gas is supplied in the presence of moisture inside the plasma processing chamber 10, tungsten fluoride oxyfluoride (WOF4) or tungsten oxide (WO3) will precipitate on the surface of the component 100 inside the plasma processing chamber 10. Therefore, the plasma processing system according to the embodiment performs a method of adjusting the internal environment of the plasma processing containing tungsten gas after first removing the moisture inside the plasma processing chamber 10.

[0030] Figure 3 This is a flowchart illustrating the processing flow of the adjustment method involved in the embodiment. Under the control of the control unit 2, the plasma processing system sequentially performs the adjustment as a method. Figure 3 The steps shown are moisture removal (step S1), seasoning (step S2), and flow calibration (step S3).

[0031] The moisture removal step in the conditioning method is a step to remove moisture from the plasma processing chamber 10. In this moisture removal step, for example, with the substrate W placed on the substrate support 11, a dry cleaning gas is supplied by the gas supply unit 20, and RF source power is supplied from the RF power supply 31 to the conductive components to perform plasma processing (dry cleaning). As a result, plasma is generated in the plasma processing space 10s, removing moisture and appropriate deposits adhering to the various components within the plasma processing chamber 10. These deposits include, for example, substances formed by the accumulation of reaction products generated during substrate processing prior to the dry cleaning step.

[0032] The appropriate gas for dry cleaning should be selected based on the amount of moisture and accumulated material. However, tungsten-containing gases should be avoided in dry cleaning. Examples of suitable dry cleaning gases include tetrafluoromethane (CF4) and oxygen (O2). CF4 is a carbon (C) and fluorine (F) gas, which can remove moisture or accumulated material by reacting with it. O2 can also remove moisture by reacting with it.

[0033] Figure 4 Table (A) illustrates the processing conditions for a moisture removal process. In the moisture removal process, for example, the steps are performed sequentially from the top column to the bottom column. Figure 4 The three steps are shown in Table (A). Specifically, in the first step, the pressure inside the plasma processing chamber 10 is set to 100 mT. Furthermore, the HF power supplied from the RF power supply 31 at a frequency of 3 MHz to 150 MHz is set to 600 W, and the LF power supplied from the RF power supply 31 at a frequency of 400 kHz to 13.56 MHz is set to 300 W. The main gas supplied in the first step is O2 gas, and its flow rate is set to 500 sccm. The temperature (cooling temperature) of the heat transfer fluid supplied to the flow path of the temperature control module is set to 90°C. Moreover, the time for performing this first step is set to 120 seconds.

[0034] In the moisture removal process, a second step is performed after the first step described above. In the second step, the pressure inside the plasma processing chamber 10 is set to 100 mT, and the cooling temperature is set to 90°C. The HF power is set to 700 W, and the LF power is set to 60 W. The main gas supplied in the second step is CF4 gas, and its flow rate is set to 250 sccm. Furthermore, the duration of this second step is set to 120 seconds.

[0035] Furthermore, in the moisture removal process, a third step is performed immediately after the second step described above. In the third step, the pressure inside the plasma processing chamber 10 is set to 200 mT, and the cooling temperature is set to 90°C. The HF power is set to 700 W, and the LF power is set to 250 W. The main gas supplied in the second step is O2 gas, and its flow rate is set to 500 sccm. Moreover, the duration of this third step is set to 30 seconds.

[0036] In the moisture removal process, with the substrate W for dry cleaning treatment housed in the plasma processing chamber 10, the dry cleaning treatment described in steps 1 to 3 above is performed to remove moisture from the plasma processing chamber 10. The substrate W for dry cleaning treatment can be a dummy substrate or a substrate W identical to the actual plasma treatment substrate.

[0037] However, performing only one cycle of dry cleaning (steps 1 to 3) is insufficient to remove moisture from the plasma processing chamber 10. Therefore, in the moisture removal process, the moisture in the plasma processing chamber 10 is thoroughly removed by repeatedly performing the dry cleaning process (steps 1 to 3).

[0038] Figure 4 Table (B) shows the relationship between the number of dry cleaning cycles and the hydrogen luminescence intensity remaining in the plasma processing chamber 10. Hydrogen luminescence intensity is an indicator related to the amount of hydrogen (in other words, the amount of moisture) in the plasma processing chamber 10. It can be said that if the hydrogen luminescence intensity is high, there is a large amount of moisture in the plasma processing chamber 10; if the hydrogen luminescence intensity is low, there is almost no moisture in the plasma processing chamber 10.

[0039] like Figure 4 As shown in (B), the hydrogen luminescence intensity is high when the number of dry cleaning cycles is low. As the number of dry cleaning cycles increases to 10 and 20, the hydrogen luminescence intensity gradually decreases. Furthermore, after 30 cycles of dry cleaning, the hydrogen luminescence intensity becomes approximately constant. In this case, it can be said that moisture can be removed with almost no residual moisture in the plasma processing chamber 10. Additionally, in Figure 4 In (B), considering the need for more reliable removal of residual moisture and increased throughput until the plasma treatment apparatus 1 begins operation, the number of dry cleaning cycles is increased to 50, and the hydrogen luminescence intensity is measured. Based on the above, the number of dry cleaning cycles as the moisture removal process is preferably set in the range of 30 to 50. In this embodiment, the number of cycles is set to 50.

[0040] Alternatively, the plasma processing system can also perform a waferless dry cleaning process during the moisture removal process, where the substrate W is not contained within the plasma processing chamber 10. For example, the moisture removal process can also incorporate waferless dry cleaning during the intervals of the dry cleaning cycle in which the substrate W is contained within the plasma processing chamber 10.

[0041] After the aforementioned moisture removal process, the adjustment method, under the control of control unit 2, is transferred to the air-drying process. Figure 3 Step S2). The drying process of the adjustment method is a process of adjusting the internal environment of the plasma processing chamber 10 to supply tungsten-containing gas for plasma treatment. The internal environment of the plasma processing chamber 10 is adjusted to be optimal for the new processing conditions. As a result, the etching rate of the plasma treatment can be stabilized from the beginning of the plasma treatment.

[0042] This drying process, for example, involves supplying drying gas through the gas supply unit 20 while the substrate W is placed on the substrate support 11, and supplying RF source power from the RF power supply 31 to the conductive components to adjust the internal environment within the plasma processing chamber 10. In this case, plasma processing can be performed within the plasma processing chamber 10 using actual substrate processing conditions (processes).

[0043] Therefore, it is preferable to select the same type of gas for drying as the gas supplied during substrate processing, with the plasma processing apparatus 1 supplying tungsten-containing gas (WF gas) as the main gas for the drying process. However, the amount of WF gas supplied is preferably greater than the amount supplied when the plasma processing apparatus 1 is in operation (when plasma processing is actually performed on the substrate W housed in the plasma processing chamber 10). For example, if the amount of WF gas supplied when the plasma processing apparatus 1 is in operation is 5 sccm, the amount supplied in the drying process is set to 7 sccm to 12 sccm. Alternatively, in the drying process, only WF gas and Ar gas can be supplied, without supplying other additive gases added during the operation of the plasma processing apparatus 1. With this drying process method, the adjustment method can perform drying processing with WF gas as the main component, and the internal environment corresponding to WF gas can be smoothly adjusted.

[0044] Figure 5 Table (A) is an example of the processing conditions for the air-drying process. In the air-drying process, ... Figure 5 The drying process is performed under the conditions shown in Table (A) as one cycle. Specifically, during the drying process, the pressure inside the plasma processing chamber 10 is set to 10 mT. Furthermore, the HF power supplied from the RF power supply 31 at a frequency of 3 MHz to 150 MHz is set to 800 W, and the LF power supplied from the RF power supply 31 at a frequency of 400 kHz to 13.56 MHz is set to 200 W. The main gases supplied during the drying process are WF gas and Ar gas; the flow rate of WF gas is set to 7 sccm, and the flow rate of Ar gas is set to 400 sccm. The temperature (cooling temperature) of the heat transfer fluid supplied to the flow path of the temperature control module is set to 50°C. The drying time is set to 120 seconds.

[0045] Through this drying process, the internal environment of the plasma processing chamber 10 is adjusted to a state suitable for substrate processing using tungsten-containing gas. However, if the drying process is only performed once, the internal environment of the plasma processing chamber 10 cannot be sufficiently adjusted. Therefore, in the drying process, the internal environment of the plasma processing chamber 10 is adjusted by repeatedly performing the drying process multiple times.

[0046] Figure 5 Table (B) shows the relationship between the number of drying cycles and the etching rate of the silicon oxide film implemented in the plasma processing chamber 10. The etching rate of the silicon oxide film is an indicator related to the internal environment within the plasma processing chamber 10. If the etching rate of the silicon oxide film is high, the internal environment within the plasma processing chamber 10 is unstable; if the etching rate is stable, it can be said that the internal environment within the plasma processing chamber 10 has been properly conditioned.

[0047] like Figure 5 As shown in (B), the etching rate of the silicon oxide film is relatively high when the number of air-drying cycles is low. As the number of air-drying cycles increases to 10 and 20, the etching rate gradually decreases. Furthermore, after 30 air-drying cycles, the etching rate becomes approximately constant. In this case, it can be considered that the plasma processing chamber 10 has been adjusted to an internal environment suitable for plasma processing using WF gas. Additionally, in Figure 4In (B), considering the need to reliably adjust the margin of the internal environment and increase the throughput until the plasma processing apparatus 1 begins operation, the number of air-drying cycles is increased to 60, and the etching rate of the silicon oxide film is measured. Based on the above, the number of air-drying cycles as the air-drying process is preferably set in the range of 30 to 60. In this embodiment, the number of cycles is set to 50.

[0048] In addition, the plasma processing system can also incorporate dry cleaning processes (including wafer-free dry cleaning processes) at appropriate intervals, such as during the intervals between air-drying cycles. This, for example, can remove deposits generated during multiple air-drying processes and suppress residual deposits within the plasma processing chamber 10.

[0049] Following the aforementioned drying process, the adjustment method, under the control of control unit 2, is transferred to the flow calibration process. Figure 3 Step S3). The flow calibration process of the adjustment method is a process of calibrating the flow controller 22 used to adjust the flow rate of WF gas supplied into the plasma processing chamber 10.

[0050] For example, in the flow calibration process, the plasma processing apparatus 1 supplies WF gas from the gas source 21 of the gas supply unit 20, adjusts the WF gas flow rate in the flow controller 22 to the target flow rate indicated by the control unit 2, and supplies it into the plasma processing chamber 10. Then, the plasma processing apparatus 1 calculates the difference between the actual flow rate and the target flow rate based on the detection information by detecting the flow rate of WF gas in the plasma processing chamber 10 or the flow rate of WF gas in the exhaust gas, and calibrates the flow controller 22.

[0051] Figure 6 This is a chart comparing the flow rates of WF gas with and without flow calibration. Figure 6 The two bar charts on the left show the gas flow rate and error rate when only the moisture removal process was performed, but the flow rate calibration process was not performed, and the WF gas flow rate was adjusted. Figure 6 The two bars in the center represent the gas flow rate and error rate when the WF gas flow rate was adjusted without a flow calibration step after the moisture removal and drying processes. Figure 6 The two bars on the right side of the graph represent the gas flow rate and error rate after the moisture removal and drying processes, followed by a flow calibration process to adjust the WF gas flow rate. Additionally, each of the two bars represents the results of multiple (twice) measurements performed to confirm the reproducibility of the experiment.

[0052] When only the moisture removal process is performed, the flow rate of WF gas is approximately 4.6 to 4.7 sccm relative to the target flow rate of 5 sccm, which is insufficient. On the other hand, when both the moisture removal and drying processes are performed, the flow rate of WF gas becomes sufficiently close to the target flow rate (5 sccm) (4.9 sccm) compared to the flow rate of WF gas with only the moisture removal process. In other words, it can be said that the adjustment method, by implementing the drying process of supplying WF gas, can adjust the state of the WF gas inside the plasma processing chamber 10.

[0053] Then, after performing the moisture removal, drying, and flow calibration processes, the flow rate can be made approximately consistent with the target flow rate (5 sccm). That is, in the adjustment method, by performing the flow calibration process at the end, the flow rate of WF6 gas in the flow controller 22 can be appropriately corrected. Specifically, in the adjustment method, since the drying process is performed before the flow calibration process, the flow controller 22 is calibrated while the internal environment within the plasma processing chamber 10 is adjusted. Therefore, the adjustment method can calibrate the flow controller 22 with higher precision. As a result, the plasma processing apparatus 1 can stably supply the target flow rate of WF gas into the plasma processing chamber 10 during actual substrate processing.

[0054] The adjustment methods involved in the above implementation methods are summarized as follows: (as follows) Figure 7 The time series shown illustrates the adjustment method during device startup or after maintenance. Figure 7 This is a time series diagram of the adjustment method involved in the implementation method.

[0055] In the conditioning method of the plasma processing system before supplying tungsten-containing gas to the substrate, steps 1 to 3 of the dry cleaning process in the moisture removal process (step S1: (A)) are repeated multiple times (e.g., 50 cycles). Next, the air drying process in the air drying process (step S2: (B)) is repeated multiple times (e.g., 50 cycles). Finally, a flow calibration process (step S3: (C)) is performed.

[0056] Therefore, after implementing the adjustment method, the plasma processing system can stably supply WF gas during the actual substrate processing process, thereby improving the accuracy of plasma processing. In particular, since the plasma processing system can precisely adjust the WF gas flow rate from the beginning of substrate processing, the defect rate at the start of substrate processing can be significantly reduced.

[0057] Furthermore, the adjustment method and plasma processing system are not limited to the embodiments described above, and various modifications can be adopted. For example, although a flow calibration step is performed in the adjustment method, this flow calibration step may not be performed. As described above, by performing the drying step, the flow rate of WF6 gas supplied to the plasma processing chamber 10 can be made sufficiently close to the target flow rate.

[0058] Furthermore, in the above embodiment, a plasma processing system that performs plasma etching while forming a tungsten protective film on a mask film on the surface of the substrate W was described. However, the plasma processing system may also be a structure that performs etching, ashing, etc., as plasma processing. Furthermore, the adjustment method is not limited to being performed during device startup or maintenance, but may also be performed when the processing conditions for plasma processing of the substrate W are changed.

[0059] The above-disclosed implementation methods include, for example, the following.

[0060] [Postscript 1] An adjustment method is a method for adjusting a plasma processing chamber capable of supplying tungsten-containing gas internally and performing plasma treatment on a substrate housed therein, comprising the following steps: (A) A process of removing moisture from the plasma processing chamber using a gas that does not contain the tungsten-containing gas; and (B) A process that, after the step in (A), generates plasma while supplying a gas containing the tungsten-containing gas, thereby adjusting the internal environment of the plasma processing chamber.

[0061] [Postscript 2] According to the adjustment method described in Appendix 1, it has the following characteristics: (C) After the step in (B), a step is performed to calibrate the flow controller used to control the flow rate of the tungsten-containing gas.

[0062] [Postscript 3] According to the adjustment method described in Appendix 1 or 2, wherein, The tungsten-containing gas includes any one of WF6 gas, WCl5 gas, or WCl6 gas.

[0063] [Postscript 4] According to the adjustment method described in Appendix 3, wherein, In step (B), the amount of tungsten-containing gas supplied is greater than the amount of tungsten-containing gas supplied when the substrate housed in the plasma processing chamber is actually subjected to plasma processing.

[0064] [Postscript 5] According to the adjustment method described in any one of Appendices 1 to 4, wherein, In the process of (A), CF gas and O2 gas are supplied as a gas that does not contain the tungsten-containing gas.

[0065] [Postscript 6] According to the adjustment method described in any one of Appendices 1 to 5, wherein, The process described in (A) involves repeatedly supplying a gas that does not contain the tungsten-containing gas to the plasma processing chamber while generating plasma.

[0066] [Postscript 7] According to the adjustment method described in Appendix 6, wherein, The number of times the process in step (A) is set to be 30 to 50.

[0067] [Postscript 8] According to the adjustment method described in any one of Appendices 1 to 7, wherein, The process described in (B) involves repeatedly supplying a gas containing the tungsten-containing gas to the plasma processing chamber while generating plasma.

[0068] [Postscript 9] According to the adjustment method described in Appendix 8, wherein, The number of times the process in step (B) is set to be 30 to 60.

[0069] [Postscript 10] A plasma processing system comprising: Plasma processing chamber; The gas supply unit supplies tungsten-containing gas into the plasma processing chamber; A power source supplies electricity to the plasma processing chamber to generate plasma; and The control unit controls the gas supply unit and the power supply. The control unit controls the following processes: (A) A process of removing moisture from the plasma processing chamber using a gas that does not contain the tungsten-containing gas; and (B) A process that, after the step in (A), generates plasma while supplying a gas containing the tungsten-containing gas, thereby adjusting the internal environment of the plasma processing chamber.

[0070] The adjustment methods and plasma processing systems disclosed herein are illustrative and not restrictive in all respects. The embodiments can be modified and altered in various ways without departing from the scope and spirit of the claims. The items described in the foregoing embodiments can also be employed in other structures without contradiction, and can be combined without contradiction.

[0071] The plasma processing apparatus disclosed herein can also be applied to any type of apparatus, including Atomic Layer Deposition (ALD), Capacitively Coupled Plasma (CCP), Inductively Coupled Plasma (ICP), Radial Line Slot Antenna (RLSA), Electron Cyclotron Resonance Plasma (ECR), and Helicon Wave Plasma (HWP).

[0072] This application claims priority to basic application No. 2023-182011 filed with the Japan Patent Office on October 23, 2023, the entire contents of which are incorporated herein by reference.

[0073] Symbol Explanation 1: Plasma processing device 2: Control Department 10: Plasma processing chamber 20: Gas Supply Department 30: Power supply W: substrate.

Claims

1. A method for regulating a plasma processing chamber capable of supplying tungsten-containing gas internally and performing plasma processing on a substrate housed therein, comprising the following steps: (A) A process of removing moisture from the plasma processing chamber using a gas that does not contain the tungsten-containing gas; and (B) A process following the step in (A) to adjust the internal environment of the plasma processing chamber by generating plasma while supplying a gas containing the tungsten gas.

2. The adjustment method according to claim 1, comprising: (C) After the step in (B), a step is performed to calibrate the flow controller used to control the flow rate of the tungsten-containing gas.

3. The adjustment method according to claim 1 or 2, wherein, The tungsten-containing gas includes any one of WF6 gas, WCl5 gas, or WCl6 gas.

4. The adjustment method according to claim 3, wherein, In step (B), the amount of tungsten-containing gas supplied is greater than the amount of tungsten-containing gas supplied when the substrate housed in the plasma processing chamber is actually subjected to plasma processing.

5. The adjustment method according to claim 1 or 2, wherein, In the process of (A), CF gas and O2 gas are supplied as a gas that does not contain the tungsten-containing gas.

6. The adjustment method according to claim 1 or 2, wherein, The process described in (A) involves repeatedly supplying a gas that does not contain the tungsten-containing gas to the plasma processing chamber while generating plasma.

7. The adjustment method according to claim 6, wherein, The number of times the process in step (A) is set to be 30 to 50.

8. The adjustment method according to claim 1 or 2, wherein, The process described in (B) involves repeatedly supplying a gas containing the tungsten-containing gas to the plasma processing chamber while generating plasma.

9. The adjustment method according to claim 8, wherein, The number of times the process in step (B) is set to be 30 to 60.

10. A plasma processing system, comprising: Plasma processing chamber; A gas supply unit supplies tungsten-containing gas into the plasma processing chamber; A power source that supplies power to the plasma processing chamber to generate plasma; and The control unit controls the gas supply unit and the power supply. The control unit controls the following processes: (A) A process of removing moisture from the plasma processing chamber using a gas that does not contain the tungsten-containing gas; and (B) A process following the step in (A) to adjust the internal environment of the plasma processing chamber by generating plasma while supplying a gas containing the tungsten gas.

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