Plasma processing method and plasma processing apparatus
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-26
- Publication Date
- 2026-08-13
Smart Images
Figure JP2026002460_13082026_PF_FP_ABST
Abstract
Description
Plasma processing method and plasma processing apparatus
[0001] This disclosure relates to a plasma processing method and a plasma processing apparatus.
[0002] Patent Document 1 discloses a plasma treatment method in which a conditioning step is performed to bring the internal environment of the chamber closer to the plasma treatment environment before plasma treatment of a semiconductor wafer. In this conditioning step, for example, hydrogen (H) ２ After generating plasma for a predetermined time, the hydrogen and argon gases in the chamber are evacuated.
[0003] Incidentally, in recent years, with the advancement of miniaturization in substrate processing, there has been a growing need for critical dimension (CD) control, such as forming patterns in the angstrom range during plasma processing. Hydrogen remaining in the chamber before plasma processing of semiconductor wafers can potentially affect the CD control during plasma processing.
[0004] Japanese Patent Publication No. 2019-12746
[0005] This disclosure provides a technology that can improve the precision of plasma processing.
[0006] According to one aspect of the present disclosure, a plasma processing method is provided, comprising: (A) a step of adjusting the state inside the chamber; and (B) a step of supplying at least a hydrogen-containing gas and a fluorine-containing gas into the chamber after step (A), generating plasma from the supplied gases, and performing plasma processing on a substrate housed in the chamber, wherein step (A) includes (A-a) a step of adjusting the state inside the chamber based on the processing conditions of the plasma processing in step (B), and (A-b) a step of supplying only a hydrogen-containing gas, or a mixed gas obtained by mixing a hydrogen-containing gas with at least one of a noble gas or an inert gas, to the chamber separately from step (A-a) in order to adjust the amount of hydrogen inside the chamber.
[0007] According to one embodiment, the precision of plasma processing can be improved.
[0008] This figure schematically shows a plasma processing system according to one embodiment. Figure 2(A) is a flowchart showing the operation method of the plasma processing system. Figure 2(B) is a flowchart showing the procedure of the seasoning process. This graph illustrates the ratio of hydrogen emission intensity for each plasma processing step when the substrate processing step is performed after the seasoning process using a conventional operation method. Figure 4(A) is a graph showing the relationship between the number of substrates processed in plasma processing and the hydrogen emission intensity. Figure 4(B) is a graph showing the relationship between the duration of the hydrogen deposition step and the hydrogen emission intensity. This is a flowchart showing the operation method of the plasma processing system. This is a timing chart showing the case when processing is performed by changing the processing conditions from product A to product B. This is a timing chart showing the operation method when the equipment is maintained.
[0009] The following describes embodiments for implementing this disclosure with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.
[0010] Figure 1 is a schematic diagram showing a plasma processing system according to one embodiment. The following describes an example of the configuration of the plasma processing system with reference to Figure 1.
[0011] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The capacitively coupled plasma processing apparatus 1 includes a 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 unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is located inside the chamber 10. The shower head 13 is located above the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a portion of the ceiling of the chamber 10. The chamber 10 has a plasma processing space 10s defined by the shower head 13, the side wall 10a of the chamber 10, and the substrate support unit 11. The 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 side wall 10a is grounded. The shower head 13 and the substrate support portion 11 are electrically insulated from the chamber 10 housing.
[0012] 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 in a plan view. The substrate W is placed on the central region 111a of the main body portion 111, and the ring assembly 112 is placed on the annular region 111b of the main body portion 111 so as to surround 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 a conductive member. The conductive member of the base functions as a lower electrode. The electrostatic chuck is placed on the base. The upper surface of the electrostatic chuck has a central region 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. Although not shown in the figures, 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 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. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate W and the central region 111a.
[0013] The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlet ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s through the plurality of gas inlet ports 13c. The shower head 13 also includes a conductive member. The conductive member of the shower head 13 functions as an upper electrode. In addition to the shower head 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.
[0014] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one processing gas to the shower head 13 from a corresponding gas source 21 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include one or more flow modulation devices that modulate or pulse the flow rate of at least one processing gas.
[0015] The power supply 30 includes an RF power supply 31 coupled to the 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 showerhead 13. This causes plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, 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 chamber 10. Furthermore, by supplying a bias RF signal to the conductive members of the substrate support 11, a bias potential is generated on the substrate W, and ionic components in the formed plasma can be drawn into the substrate W.
[0016] 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 unit 11 and / or a conductive member of the shower 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 13 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. One or more generated source RF signals are supplied to the conductive member of the substrate support unit 11 and / or a conductive member of the shower head 13. The second RF generation unit 31b is coupled to a conductive member of the substrate support unit 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 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated bias RF signals are supplied to the conductive member of the substrate support unit 11. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.
[0017] The power supply 30 may also include a DC power supply 32 coupled to the chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to a conductive member of the substrate support unit 11 and configured to generate a first DC signal. The generated first bias DC signal is applied to the conductive member of the substrate support unit 11. In one embodiment, the first DC signal may be applied to other electrodes, such as electrodes in an electrostatic chuck. In one embodiment, the second DC generation unit 32b is connected to a conductive member of the shower head 13 and configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the shower head 13. In various embodiments, at least one of the first and second DC signals may be pulsed. The first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, and the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.
[0018] The exhaust system 40 may be connected to, for example, a gas outlet 10e located at the bottom of the chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.
[0019] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described herein. The control unit 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 control unit 2 may be included in the plasma processing apparatus 1. The control unit 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 perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).
[0020] The control unit 2 controls each component of the plasma processing apparatus 1 to perform plasma processing on the substrate W housed in the chamber 10. In the plasma processing system according to this embodiment, the gas supply unit 20 supplies etching gas to the chamber 10 as a processing gas, and the RF power supply 31 supplies RF power to conductive members (substrate support unit 11, shower head 13) to etch the substrate W. For example, the control unit 2, based on the processing conditions for plasma processing set in the recipe, supplies at least a fluorine-containing gas, carbon tetrafluoride (CF4). ４ ) CF-based gases such as or silicon tetrafluoride (SiF ４ Along with ) gases, etc., hydrogen-containing gases (H ２ The gas is supplied into the chamber 10. The plasma processing apparatus 1 generates plasma from these supplied processing gases in the plasma processing space 10s, thereby etching the surface of the substrate W. Hereinafter, plasma processing based on a recipe in which the processing conditions for seasoning plasma processing are set will also be referred to as seasoning product recipe plasma processing.
[0021] Note that the processing gas may contain noble gases such as helium (He) gas and argon (Ar) gas, oxygen-containing gases such as oxygen (O ２ ) gas and ozone (O ３ ) gas, or inert gases such as nitrogen (N ２ ) gas, or other gases. Further, the plasma processing system may be configured to supply a gas of a molecule having a hydrogen atom (H) into the chamber 10 according to the content of the plasma processing on the substrate W. For example, as the gas of a molecule having a hydrogen atom, there are hydrofluorocarbon (CHF-based) gases such as trifluoromethane (CHF ３ ) gas, ammonia (NH ３ ) gas, hydrogen chloride (HCl) gas, hydrofluoric acid (HF) gas, and other hydrocarbon-based gases. In other words, hydrogen (H ２ ) gas and a gas of a molecule having a hydrogen atom (H) are hydrogen-containing gases.
[0022] As described above, the plasma processing system according to the embodiment performs plasma processing using a hydrogen-containing gas as the processing gas. The amount of hydrogen (hydrogen amount) in the chamber 10 affects the plasma processing. Therefore, the plasma processing apparatus 1 according to the embodiment includes a configuration for monitoring the hydrogen amount in the chamber 10.
[0023] Specifically, the plasma processing apparatus 1 installs a hydrogen detection unit 80 for monitoring the amount of hydrogen present in the plasma processing space 10s on the side wall 10a (peripheral wall) of the chamber 10. As an example of an index of the amount of hydrogen in the plasma processing space 10s, an optical emission spectrometer (OES) for detecting the emission intensity of hydrogen can be applied to the hydrogen detection unit 80. For example, the hydrogen detection unit 80 includes an analyzer main body 81 and a detector 82 connected to the analyzer main body 81. Further, the chamber 10 has an accommodation space 83 for accommodating the detector 82. The detector 82 is fixed so as to seal the accommodation space 83. A protective window (not shown) may be provided between the plasma processing space 10s of the accommodation space 83 and the detector 82.
[0024] The detector 82 is equipped with a light-receiving element capable of receiving light emitted from the plasma processing space 10s. The detector 82 spectrally analyzes the light emitted in the plasma processing space 10s as the plasma is generated, receiving the light for each wavelength, and transmits spectral information of a predetermined wavelength (or all wavelengths) to the main body of the analyzer 81.
[0025] The analyzer body 81 acquires the emission intensity of hydrogen atoms present in the plasma processing space 10s at spectral wavelengths based on the spectral spectrum information obtained from the detector 82. When detecting hydrogen present in the plasma processing space 10s, it is preferable to extract the emission intensity of the 486 nm spectrum and / or the 656 nm spectrum, for example, when electrons transition from Balmer series electron orbitals, as spectral wavelengths. This allows the analyzer body 81 to monitor the emission intensity emitted according to the amount of hydrogen in the plasma processing space 10s. The analyzer body 81 is communicatively connected to the control unit 2 and detects the emission intensity of hydrogen based on a command from the control unit 2, and transmits this hydrogen emission intensity information to the control unit 2.
[0026] The plasma processing system configured as described above employs an operational method to adjust the internal environment within the chamber 10 to the new processing conditions, for example, when performing plasma processing under new processing conditions different from those previously used. This is because if the internal environment of the chamber 10 is not suited to the new processing conditions, the plasma processing will become unstable from immediately after the start of the plasma processing through multiple substrate processing cycles, resulting in the waste of the plasma-treated substrate W.
[0027] Figure 2(A) is a flowchart showing an operation method of the plasma processing system. Figure 2(B) is a flowchart showing the procedure of the seasoning process. For example, when performing plasma processing under processing conditions B using a new hydrogen-containing gas different from the processing conditions A using a hydrogen-containing gas, the control unit 2 first performs a substrate processing step (S1) using the processing conditions A as the plasma processing method. When switching the processing conditions A to the processing conditions B, the control unit 2 performs a dry cleaning step (S2) and a seasoning step (S3) in this order. After the seasoning step (S3), the control unit 2 performs a substrate processing step (S4) using the processing conditions B. Note that the dry cleaning step (S2) and the seasoning step (S3) are not only performed when switching to new processing conditions, but may also be performed when performing plasma processing under the same processing conditions without switching to new processing conditions. Further, it may be performed after the plasma processing apparatus 1 has been stopped for maintenance or the like and then started up, or after the substrate processing has been temporarily stopped.
[0028] In the dry cleaning step (S2), the control unit 2 supplies a cleaning gas to the plasma processing space 10s by the gas supply unit 20 and supplies RF source power from the RF power supply 31 to the conductive member (the substrate support unit 11 or the shower head 13). Thereby, plasma is generated in the plasma processing space 10s, and the deposits adhering to each component in the chamber 10 are removed. The deposits are, for example, reaction products generated by plasma processing in the previous (previous) substrate processing step (S1) before the dry cleaning step and deposited on each component in the chamber 10. The cleaning gas used in the dry cleaning step (S2) is appropriately selected according to the deposits to be removed. When the deposit adhering to the inside of the chamber 10 is carbon (C), for example, oxygen gas or ozone gas is supplied as the cleaning gas. Note that depending on the processing conditions of the substrate processing step (S1), reaction products may not be deposited in the chamber. In this case, the dry cleaning step (S2) may be omitted and the process may be started from the seasoning step (S3).
[0029] After the dry cleaning process (S2), the plasma processing system performs a seasoning process (S3) to adjust the internal environment of the chamber 10. As shown in FIG. 2(B), the plasma processing system according to the embodiment performs a hydrogen removal step (S101), a product recipe processing step (S102), and a hydrogen adhesion step (S103) in this order. The hydrogen removal step (S101) is a process for removing hydrogen present in the chamber 10, and conversely, the hydrogen adhesion step (S103) is a process for increasing the amount of hydrogen in the chamber 10 by attaching hydrogen to each component in the chamber 10. The conventional seasoning process (S3) only included the product recipe processing step (S102).
[0030] Here, the amount of hydrogen remaining in the chamber 10 has a very small impact on the plasma processing of the substrate W. Therefore, in the conventional operation method that performs CD control in nanometer units in the formation of the pattern of the substrate W, only the product recipe processing step (S102) was performed in the seasoning process (S3) to adjust the amount of hydrogen in the chamber 10. That is, even if an error occurred in the CD control due to the variation in the amount of hydrogen in the chamber 10, the error was negligible in nanometer units and could be considered within an acceptable range.
[0031] However, when performing CD control in angstrom units in the formation of the pattern of the substrate W, the amount of hydrogen remaining in the chamber 10 has a non-negligible impact on the plasma processing. For example, due to the variation in the amount of hydrogen remaining in the chamber 10, a deviation of several angstroms may occur during etching. In particular, when switching to new processing conditions for plasma processing, it is necessary to appropriately adjust the amount of hydrogen in the chamber 10 in the seasoning process (S3).
[0032] FIG. 3 is a graph illustrating the emission intensity ratio of hydrogen for each plasma processing when the substrate processing step (S4) is performed after the seasoning process (S3) by the conventional operation method, that is, after the product recipe processing step (S102). The vertical axis of FIG. 3 represents the emission intensity after the 5th plasma processing as 1, and shows the ratio of the emission intensity after other numbers of plasma processing to the emission intensity after the 5th plasma processing.
[0033] In conventional operating methods, when switching to plasma processing with new processing conditions for the substrate processing process, the amount of hydrogen in the chamber 10 associated with the plasma processing gradually increases from the first plasma processing and stabilizes, for example, after the fifth plasma processing. In other words, when switching to plasma processing with new processing conditions, if only the product recipe processing step (S102) is performed in the seasoning process (S3), the amount of hydrogen remaining in the chamber 10 at the start of the substrate processing process (S4) will be small. Therefore, there is a high possibility that CD control of the substrate W at the start of the substrate processing process (S4) will not be successful.
[0034] Therefore, in the operation method of the plasma processing system according to the embodiment, in the seasoning process (S3), a hydrogen removal step (S101) and a hydrogen deposition step (S103) are added in addition to the product recipe processing step (S102). This makes it possible to stabilize the amount of hydrogen in the chamber 10 in the subsequent substrate processing process (S4). The seasoning process (S3) will be described in detail below.
[0035] The hydrogen removal step (S101) is a process of removing any remaining hydrogen in the chamber 10 and resetting the amount of hydrogen in the chamber 10 (bringing it as close to zero as possible). In this hydrogen removal step (S101), the control unit 2 supplies a hydrogen removal gas, which reacts with the remaining hydrogen to form another gas, into the chamber 10 via the gas supply unit 20. Also in the hydrogen removal step (S101), the control unit 2 generates plasma in the plasma processing space 10s by supplying RF source power from the RF power supply 31 to a conductive member (substrate support unit 11 or shower head 13). Examples of hydrogen removal gases include fluorine-containing gases (one example being fluorocarbon (CF) gases). The hydrogen removal step (S101) may be carried out with or without a dummy substrate (dummy wafer, bare wafer) placed in the chamber 10.
[0036] The product recipe processing step (S102) involves placing a dummy substrate (dummy wafer, bare wafer) in the chamber 10 and performing a product recipe plasma treatment for seasoning under new processing conditions (recipe) to adjust the internal environment of the chamber 10. In other words, in the product recipe processing step (S102), plasma treatment is performed under substantially the same processing conditions as in the substrate processing step (S4), except that a dummy substrate is applied to the substrate support part 11 instead of the substrate W. Substantially the same processing conditions mean that at least the type of gas supplied to the chamber 10 to generate the plasma is the same. This adjusts the internal environment of the chamber 10 to the environment of the new processing conditions. The dummy substrate is preferably made of silicon and is a disc with substantially the same shape as the product substrate W. Since this dummy substrate does not have a hydrogen-containing film formed on its surface, hydrogen is not released from the dummy substrate into the chamber 10 during the product recipe processing step (S102).
[0037] In addition, the seasoning process (S3) is not limited to performing the product recipe processing step (S102) only once, but may be performed multiple times. This makes the internal environment of the chamber 10 closer to the internal environment obtained by repeating the substrate processing process (S4) multiple times. Alternatively, the control unit 2 may adjust the internal environment of the chamber 10 by performing the product recipe processing step (S102) with a processing time longer than the processing time of the processing conditions for the substrate processing process (S4).
[0038] When plasma processing is performed by supplying hydrogen-containing gas in the substrate processing step (S4), the product recipe processing step (S102) also involves supplying hydrogen-containing gas according to the recipe and performing plasma processing. As a result, the amount of hydrogen remaining in the chamber 10 increases slightly after the product recipe processing step (S102). However, in the plasma processing of the substrate processing step (S4), hydrogen released from the substrate W remains in the chamber 10, whereas in the product recipe processing step (S102), no hydrogen is released from the dummy substrate. Therefore, the plasma processing system compensates for the insufficient amount of hydrogen in the chamber 10 by performing a hydrogen deposition step (S103) after the product recipe processing step (S102).
[0039] The hydrogen deposition step (S103) involves supplying hydrogen-containing gas into the chamber 10 to adjust the amount of hydrogen in the chamber 10. Specifically, the control unit 2 places a dummy substrate in the chamber 10, similar to the product recipe processing step (S102), and while supplying hydrogen-containing gas via the gas supply unit 20, supplies RF power to the conductive member with the RF power supply 31 to generate a hydrogen-containing gas plasma. The dummy substrate used in the hydrogen deposition step (S103) may be replaced with the dummy substrate used in the product recipe processing step (S102), or the dummy substrate from the product recipe processing step (S102) may be used continuously. Alternatively, the dummy substrate does not need to be set in the chamber 10 in the hydrogen deposition step (S103).
[0040] In the hydrogen deposition step (S103), the control unit 2 maintains a constant supply amount of hydrogen-containing gas and RF power to stabilize the amount of hydrogen plasma generated, and also adjusts the time for generating the hydrogen plasma. In other words, the control unit 2 adjusts the time of the hydrogen deposition step (S103) to bring the amount of hydrogen in the chamber 10 to the target range.
[0041] Figure 4(A) is a graph showing the relationship between the number of substrates processed in plasma treatment and the hydrogen emission intensity. Figure 4(B) is a graph showing the relationship between the time of the hydrogen deposition step and the hydrogen emission intensity. More specifically, as shown in Figure 4(A), the control unit 2 holds map information or a function that associates the number of substrates W, which are actual products, that are plasma-treated with the hydrogen emission intensity in the chamber 10. Furthermore, as shown in Figure 4(B), the control unit 2 also holds map information or a function that associates the time of the hydrogen deposition step (S103) with the hydrogen emission intensity in the chamber 10. This map information or function is calculated in advance through experiments or simulations and stored in the control unit 2.
[0042] The control unit 2 prompts the user of the plasma processing system, for example, to input the number of plasma processing cycles to which the hydrogen amount should be adjusted, and the range of Å of the substrate W in CD control. Based on this input information, the control unit 2 calculates the emission intensity of hydrogen in the chamber 10 and the target range of this emission intensity (upper limit, lower limit: see the dashed line in Figure 4(A)) in the map information or function of Figure 4(A). Then, the control unit 2 sets the time for the hydrogen deposition step (S103) by applying the target range of hydrogen emission intensity to the map information or function of Figure 4(B). By performing the hydrogen deposition step (S103) according to this time, the control unit 2 can accurately adjust the amount of hydrogen in the chamber 10 to within the target range.
[0043] In addition, the control unit 2 may supply only hydrogen-containing gas into the chamber 10 during the hydrogen deposition step (S103), or it may supply a mixture of hydrogen-containing gas and other gases such as noble gases or inert gases. The hydrogen-containing gas is H ２ Gas, CHF ３ Gas, CH ２ F ２ Gas, CH ４ It is at least one gas selected from gases and HF gases. In order to efficiently carry out hydrogen deposition, H ２ Gas is preferred. The noble gas is at least one gas selected from He gas, Ar gas, Xe gas, and Kr gas. The inert gas is N ２ Gas, O ２ It is at least one gas selected from the gases. It may be a mixture of a hydrogen-containing gas and a noble gas, a mixture of a hydrogen-containing gas and an inert gas, or a mixture of a hydrogen-containing gas, a noble gas, and an inert gas. Specifically, H ２ Gas, H ２ A mixture of gas and Ar gas, H ２ A mixture of gas and He gas, H ２ Gas and O ２ Gas mixture, H ２ Gas and N ２ Gas mixture, H ２ Gas, Ar gas, and O ２ Gas mixture, H ２ Gas, Ar gas, and N ２ Gas mixture, H２ Gas and He gas and O ２ Gas mixture, H ２ Gas and He gas and N ２ This refers to a gas mixture consisting only of the gases mentioned above. Furthermore, the control unit 2 may increase the amount of hydrogen-containing gas supplied in the hydrogen deposition step (S103) compared to the amount of hydrogen-containing gas supplied in the seasoning product recipe plasma treatment (product recipe treatment step (S102)). Alternatively, the control unit 2 may be configured to supply and exhaust hydrogen-containing gas into and out of the chamber 10 without generating plasma.
[0044] Returning to Figures 2(A) and 2(B), the control unit 2 terminates the seasoning process (S3) after completing the hydrogen deposition step (S103). This allows the plasma processing system to adjust the internal environment of the chamber 10 to an environment where the substrate W can be plasma-processed with high precision from the start of the substrate processing process (S4).
[0045] In addition, the hydrogen removal step (S101) is not necessarily required in the seasoning process (S3). For example, if the amount of hydrogen in the chamber 10 (hydrogen emission intensity) is detected accurately, the hydrogen removal step (S101) is omitted, and the processing content (processing time, amount of hydrogen-containing gas supplied) is controlled in the hydrogen deposition step (S103) to add the necessary amount of hydrogen. Even in this case, the plasma processing system can efficiently adjust the total amount of hydrogen in the chamber 10 to the target range.
[0046] Furthermore, if a gas capable of removing hydrogen (for example, a fluorine-containing gas) is supplied as the cleaning gas in the dry cleaning process (S2) to remove hydrogen, then the dry cleaning process (S2) itself becomes a hydrogen removal step (S101). In this case, the hydrogen removal step (S101) may be omitted in the seasoning process (S3). Conversely, if hydrogen gas or a hydrogen-containing gas is supplied as the cleaning gas in the dry cleaning process (S2) to perform cleaning, it is preferable to carry out the hydrogen removal step (S101). This helps to prevent an excess of hydrogen in the chamber 10.
[0047] Furthermore, in the operation method of the plasma processing system, during the substrate processing step (S4), the hydrogen detection unit 80 detects the emission intensity of hydrogen in the plasma processing space 10s and compares whether the emission intensity of hydrogen in the plasma processing space 10s is within the target range. That is, the control unit 2 monitors the amount of hydrogen in the chamber 10 when performing plasma processing on the substrate W in the substrate processing step (S4). Then, if the amount of hydrogen (emission intensity of hydrogen) falls outside the target range, the control unit 2 moves from the substrate processing step (S4) to the dry cleaning step (S2) and the seasoning step (S3).
[0048] In this case, during the seasoning process (S3), the control unit 2 sequentially performs the hydrogen removal step (S101), the product recipe processing step (S102), and the hydrogen deposition step (S103). As a result, even if the amount of hydrogen in the chamber 10 falls outside the target range, the plasma processing system can immediately adjust the amount of hydrogen to return it to the target range, making it possible to perform the substrate processing process (S4) again with high accuracy.
[0049] For example, if the amount of hydrogen in the chamber 10 decreases and the hydrogen removal step (S101) is not performed, the control unit 2 may set the time of the hydrogen deposition step (S103) using the hydrogen emission intensity of the plasma processing space 10s measured last in the substrate processing step (S4). This makes it possible for the plasma processing system to adjust the amount of hydrogen in the chamber 10 effectively while shortening the time of the seasoning process (S3).
[0050] The plasma processing system according to this embodiment is basically configured as described above. Below, the processing flow and timing chart summarizing the operation method will be explained with reference to Figures 5 and 6. Figure 5 is a flowchart showing the operation method of the plasma processing system.
[0051] The control unit 2 continuously monitors changes in the plasma processing conditions during the execution of the substrate processing step of the plasma processing method (S1: see Figure 2(A)). Specifically, the control unit 2 determines whether the processing conditions B for the next plasma processing are different from the processing conditions A for the plasma processing up to this point (step S201). If the processing conditions for the plasma processing are different (step S201: YES), the process proceeds to step S202. If the processing conditions for the plasma processing are the same (step S201: NO), steps S202 to S205 are skipped and the process proceeds to step S206.
[0052] Steps S202 to S205 correspond to the dry cleaning process (S2) and the seasoning process (S3) in Figure 2(A). The control unit 2 first performs step S202 as the dry cleaning process (S2) to remove deposits in the chamber 10. After the execution of step S202, the operation method proceeds to the seasoning process (S3).
[0053] Specifically, the control unit 2 performs step S203 as the hydrogen removal step (S101) in Figure 2(B), removing any remaining hydrogen in the chamber 10 and bringing the amount of hydrogen in the chamber 10 close to zero.
[0054] Next, the control unit 2 performs step S204 as the product recipe processing step (S102) in Figure 2(B), adjusting the internal environment of the chamber 10 to match the processing conditions for the plasma treatment.
[0055] Then, the control unit 2 performs step S205 as the hydrogen deposition step (S103) in Figure 2(B), adjusting the amount of hydrogen in the chamber 10 to match the amount of hydrogen for the current plasma treatment. Once step S205 is completed, the seasoning process (S3) is finished, and the internal environment of the chamber 10, including the amount of hydrogen, is prepared.
[0056] After step S205 is executed, or if the processing conditions for the current operation are the same as those for the previous operation, the control unit 2 performs step S206 as the substrate processing step (S4) shown in Figure 2(A). Because the internal environment of the chamber 10 has been adjusted by the processing flow so far, the plasma processing apparatus 1 can perform plasma processing on the substrate W housed in the chamber 10 with high precision.
[0057] Furthermore, during the execution of the substrate processing process (S1), the plasma processing system detects the emission intensity of hydrogen in the chamber 10 using the hydrogen detection unit 80. The control unit 2 then monitors the amount of hydrogen in the chamber 10 using the emission intensity of hydrogen measured by the hydrogen detection unit 80 after the plasma processing of the substrate W. Specifically, the control unit 2 determines whether the emission intensity of hydrogen in the chamber 10 is within the target range (step S207). If the emission intensity of hydrogen is within the target range (step S206: YES), it means that the amount of hydrogen in the chamber 10 is being maintained appropriately, and the processing flow is terminated.
[0058] On the other hand, if the hydrogen emission intensity falls outside the target range (step S206: NO), it means that the amount of hydrogen in the chamber 10 has changed. In this case, even if the next plasma treatment is performed, it may not be possible to adequately control the CD for the substrate W. Therefore, the control unit 2 returns to step S202 and performs control to repeat the processing flow from step S202 onward. As a result, even if the amount of hydrogen in the chamber 10 changes during the substrate processing step (S4), the plasma processing system can immediately adjust the internal environment of the chamber 10 and continue the plasma processing stably.
[0059] Figure 6 shows the timing chart when processing is performed by changing the processing conditions from product A to product B. In the plasma processing method described above, when switching from processing conditions A for product A to processing conditions B for product B, the timing chart will be as shown in Figure 6. Specifically, the plasma processing system manufactures product A multiple times using the substrate processing step (S1) with processing conditions A. When conditions such as switching to processing conditions B are met, the plasma processing system sequentially performs the dry cleaning step (S2), hydrogen removal step (S101), product recipe processing step (S102), and hydrogen deposition step (S103). After that, the plasma processing system manufactures product B multiple times using the substrate processing step (S4) with processing conditions B.
[0060] As a result, the internal environment of the chamber 10 becomes an environment that matches the processing conditions B for product B. Therefore, the plasma processing system can perform highly accurate plasma processing from the start of the substrate processing process (S4) of product B, and it becomes possible to perform the substrate processing process (S4) multiple times.
[0061] As described above, the plasma processing system and operating method according to the embodiment can adjust the amount of hydrogen in the chamber 10 by performing a hydrogen deposition step (S103) in the seasoning process (S3). This enables the plasma processing system to perform plasma processing on the substrate W in the chamber 10 stably and with high precision, thereby improving the precision of the plasma processing.
[0062] It should be noted that the plasma processing system and operating method are not limited to the embodiments described above, and various modifications are possible. For example, in the seasoning process (S3) described above, the hydrogen removal step (S101), the product recipe processing step (S102), and the hydrogen deposition step (S103) were performed in this order. However, the order of each step in the seasoning process (S3) is not limited to this, and for example, the hydrogen deposition step (S103) may be performed between the hydrogen removal step (S101) and the product recipe processing step (S102).
[0063] Furthermore, in the above embodiment, the time for the hydrogen deposition step (S103) was set based on the map information or function shown in Figures 4(A) and 4(B). The plasma processing system is not limited to this, and in the hydrogen deposition step (S103), the system may be configured to continuously detect the emission intensity of hydrogen in the chamber 10 (an indicator of the amount of hydrogen) and terminate the process when the emission intensity reaches a target range.
[0064] In the above embodiment, a plasma processing system for etching a substrate W was described. However, the plasma processing system is not limited to a configuration that performs etching as a plasma processing, but may also be configured to perform film deposition or ashing. In this case as well, the plasma processing system can improve the accuracy of the plasma processing by appropriately adjusting the amount of hydrogen in the chamber 10. Furthermore, the configuration for detecting an indicator of the amount of hydrogen remaining in the chamber 10 is not limited to a hydrogen detection unit 80 that detects the emission intensity of hydrogen, but may also be applied, for example, a sensor that detects hydrogen concentration. Moreover, in the operation method of the plasma processing system, a dry cleaning process (S2) was performed before the seasoning process (S3), but the dry cleaning process (S2) does not have to be performed.
[0065] Furthermore, for example, the plasma processing system is not limited to performing the hydrogen deposition step (S103) only when switching between plasma processing conditions (product A and product B), but can also perform the hydrogen deposition step (S103) under other circumstances.
[0066] Figure 7 is a timing chart showing the operation method when the device has undergone maintenance. For example, as shown in Figure 7, even when the device has undergone maintenance (for example, replacement of parts in the chamber 10), the control unit 2 may still perform the hydrogen deposition step (S103) in the seasoning process (S3).
[0067] After the maintenance process is completed, the control unit 2 performs a moisture removal process to remove moisture from inside the chamber 10. In the moisture removal process, for example, an oxygen-containing gas is supplied into the chamber 10 to generate plasma, thereby removing moisture that entered the chamber 10 during maintenance. Furthermore, the control unit 2 may repeat the moisture removal process multiple times to ensure that the moisture inside the chamber 10 is completely eliminated (brought as close to zero)
[0068] After the moisture removal process, the control unit 2 performs the dry cleaning process (S2) and the seasoning process (S3) described above, and then performs the substrate processing process (S4) multiple times. During the moisture removal process, the control unit 2 can appropriately adjust the internal environment of the chamber 10 containing hydrogen by performing the hydrogen removal step (S101), the product recipe processing step (S102), and the hydrogen deposition step (S103). Note that if the same gas is supplied to generate plasma in both the moisture removal seasoning process and the dry cleaning process, one of the steps may be omitted.
[0069] The embodiments disclosed above include, for example, the following: (Note 1) A plasma treatment method comprising: (A) a step of adjusting the state inside the chamber; (B) a step of supplying at least a hydrogen-containing gas and a fluorine-containing gas into the chamber after step (A), generating plasma from the supplied gases, and performing plasma treatment on a substrate housed in the chamber, wherein step (A) comprises: (A-a) a step of adjusting the state inside the chamber based on the treatment conditions of the plasma treatment in step (B); and (A-b) a step of supplying only a hydrogen-containing gas, or a mixed gas obtained by mixing a hydrogen-containing gas with at least one of a noble gas or an inert gas, to the chamber separately from step (A-a) in order to adjust the amount of hydrogen inside the chamber. (Note 2) The plasma processing method according to Note 1, wherein in step (B), an indicator of the amount of hydrogen inside the chamber is detected, the existing target range is compared with the indicator of the amount of hydrogen, and if the indicator of the amount of hydrogen is outside the target range, step (A) is performed. (Note 3) The plasma processing method according to Note 2, wherein in step (B), the emission intensity of hydrogen is detected by a detection unit as an indicator of the amount of hydrogen, and the existing target range is compared with the emission intensity of hydrogen. (Note 4) The plasma processing method according to Note 3, wherein in step (A-b), the time of step (A-b) is set based on information showing the relationship between the emission intensity of hydrogen and the target range, and information showing the relationship between the emission intensity of hydrogen and the time of step (A-b). (Note 5) The plasma processing method according to any one of Notes 1 to 4, wherein step (A-b) is performed after step (A-a). (Note 6) The hydrogen-containing gas is H ２A plasma treatment method according to any one of Appendix 1 to 5, wherein the material is a gas. (Appendix 7) A plasma treatment method according to any one of Appendix 1 to 6, wherein the processing conditions for the current plasma treatment are compared with the processing conditions for the previous plasma treatment, and if the processing conditions for the current plasma treatment are different from those for the previous plasma treatment, step (A) is performed, and if the processing conditions for the current plasma treatment are the same as those for the previous plasma treatment, step (B) is continued. (Appendix 8) A plasma treatment method according to any one of Appendix 1 to 7, wherein in step (A-a) and step (A-b), a dummy substrate is placed inside the chamber to generate plasma inside the chamber. (Appendix 9) A plasma treatment method according to any one of Appendix 1 to 8, wherein in step (A), (A-c) a step is performed to remove hydrogen remaining inside the chamber before step (A-a) and step (A-b). (Note 10) The plasma treatment method according to any one of the items in Note 9, wherein in step (A-c), a fluorine-containing gas is supplied into the chamber to generate plasma inside the chamber. (Note 11) (C) The plasma treatment method according to any one of the items in Note 1 to 10, wherein a step of supplying a cleaning gas to remove deposits inside the chamber is performed before step (A).(Note 12) A plasma processing system comprising: a chamber capable of housing a substrate; a gas supply unit that supplies hydrogen-containing gas and fluorine-containing gas into the chamber; a power supply unit that supplies RF power to a conductive member of the chamber to generate plasma from the supplied gases; and a control unit that controls the gas supply unit and the power supply unit, wherein the control unit controls: (A) a step of adjusting the state inside the chamber; (B) a step after step (A) of supplying at least hydrogen-containing gas and fluorine-containing gas into the chamber, generating plasma from the supplied gases, and performing plasma processing on the substrate housed in the chamber, wherein step (A) controls: (A-a) a step of adjusting the internal environment of the chamber based on the processing conditions of the plasma processing in step (B); and (A-b) a step separate from step (A-a) of supplying only hydrogen-containing gas, or a mixed gas obtained by mixing hydrogen-containing gas with at least one of a noble gas or an inert gas, to the chamber in order to adjust the amount of hydrogen inside the chamber.
[0070] The plasma processing systems and operating methods according to the embodiments disclosed herein are illustrative and not restrictive in all respects. The embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be otherwise configured and combined in a non-consistent manner.
[0071] The plasma processing system described herein is applicable to any of the following types of equipment: 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 Japanese Patent Application No. 2025-018520, a basic application filed with the Japan Patent Office on February 6, 2025, the entire contents of which are incorporated herein by reference.
[0073] 2 Control unit 10 Chamber 20 Gas supply unit 30 Power supply W Circuit board
Claims
1. A plasma treatment method comprising: (A) a step of adjusting the state inside a chamber; and (B) a step of supplying at least a hydrogen-containing gas and a fluorine-containing gas into the chamber after step (A), generating plasma from the supplied gases, and performing plasma treatment on a substrate housed in the chamber, wherein step (A) comprises: (A-a) a step of adjusting the state inside the chamber based on the treatment conditions of the plasma treatment in step (B); and (A-b) a step of supplying only a hydrogen-containing gas, or a mixed gas obtained by mixing a hydrogen-containing gas with at least one of a noble gas or an inert gas, to the chamber separately from step (A-a) in order to adjust the amount of hydrogen inside the chamber.
2. The plasma treatment method according to claim 1, wherein in step (B), an indicator of the amount of hydrogen inside the chamber is detected, the existing target range is compared with the indicator of the amount of hydrogen, and if the indicator of the amount of hydrogen is outside the target range, step (A) is performed.
3. The plasma processing method according to claim 2, wherein in step (B), the emission intensity of hydrogen is detected by a detection unit as an indicator of the amount of hydrogen, and the emission intensity of hydrogen is compared with the target range held.
4. The plasma treatment method according to claim 3, wherein in step (A-b), the time of step (A-b) is set based on information indicating the relationship between the emission intensity of the hydrogen and the target range, and information indicating the relationship between the emission intensity of the hydrogen and the time of step (A-b).
5. The plasma treatment method according to any one of claims 1 to 4, wherein step (A-b) is performed after step (A-a).
6. The hydrogen-containing gas is H ２ A plasma treatment method according to any one of claims 1 to 4, wherein the material is a gas.
7. A plasma treatment method according to any one of claims 1 to 4, comprising: comparing the processing conditions of the current plasma treatment with the processing conditions of the previous plasma treatment; performing step (A) if the processing conditions of the current plasma treatment are different from the processing conditions of the previous plasma treatment; and continuing step (B) if the processing conditions of the current plasma treatment are the same as the processing conditions of the previous plasma treatment.
8. The plasma processing method according to any one of claims 1 to 4, wherein in step (A-a) and step (A-b), a dummy substrate is placed inside the chamber and plasma is generated inside the chamber.
9. The plasma treatment method according to any one of claims 1 to 4, wherein in step (A), a step of removing hydrogen remaining inside the chamber is performed before steps (A-a) and (A-b).
10. The plasma treatment method according to claim 9, wherein in step (A-c), a fluorine-containing gas is supplied into the chamber to generate plasma inside the chamber.
11. (C) A plasma treatment method according to any one of claims 1 to 4, wherein a step of supplying a cleaning gas to remove deposits inside the chamber is performed prior to step (A).
12. A plasma processing apparatus comprising: a chamber capable of housing a substrate; a gas supply unit that supplies hydrogen-containing gas and fluorine-containing gas into the chamber; a power supply unit that supplies RF power to a conductive member of the chamber to generate plasma from the supplied gases; and a control unit that controls the gas supply unit and the power supply unit, wherein the control unit controls: (A) a step of adjusting the state inside the chamber; (B) a step after step (A) of supplying at least hydrogen-containing gas and fluorine-containing gas into the chamber, generating plasma from the supplied gases, and performing plasma processing on the substrate housed in the chamber, and in step (A), (A-a) a step of adjusting the state inside the chamber based on the processing conditions of the plasma processing in step (B); and (A-b) a step separate from step (A-a) of supplying only hydrogen-containing gas, or a mixed gas obtained by mixing hydrogen-containing gas with at least one of a noble gas or an inert gas, to the chamber in order to adjust the amount of hydrogen inside the chamber.