Deposition state monitoring method and substrate processing apparatus

Abstract

The present invention provides a deposition state monitoring method and a substrate processing apparatus capable of early and easy estimation of a deposition state of a pump. The deposition state monitoring method monitors a deposition state of a deposit deposited in a pump connected to a processing container of a substrate processing apparatus that processes a substrate. The deposition state monitoring method includes a step of acquiring a current value of a motor that rotates a rotating structure of the pump; a step of causing a damped waveform to occur in a time change of the current value by supplying a processing gas to the processing container; a step of acquiring a top peak current value of a plurality of peak portions constituting the damped waveform and a valley bottom current value of a same number of valley portions as the plurality of peak portions; a step of calculating an estimated convergence current value at which the damped waveform converges by taking an average of the top peak current value of the plurality of peak portions and the valley bottom current value of the plurality of valley portions; and a step of estimating the deposition state of the deposit based on the estimated convergence current value.

Description

TECHNICAL FIELD

[0001] The present application relates to a deposition state monitoring method and a substrate processing apparatus. BACKGROUND

[0002] A substrate processing apparatus used in the manufacture of semiconductors performs exhaust of a processing gas in a processing container by a turbo molecular pump. At the time of exhaust, deposits of reaction products generated in substrate processing, by-products which do not contribute to substrate processing, and the like are deposited in the turbo molecular pump. A technique is disclosed in Patent Literature 1 which monitors a current value supplied to the turbo molecular pump by a control device to estimate a deposition state of deposits of the turbo molecular pump.

[0003] In the estimation of the deposition state, the accuracy of estimation decreases when the current value of the turbo molecular pump is small, and thus the current value at the time when a load is applied to the turbo molecular pump by introduction of a processing gas into the processing container is used. At the start of introduction of the processing gas, the current value supplied to the turbo molecular pump sharply becomes large and then forms a damped waveform in which the amplitude repeatedly converges gradually.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2021-179187 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The present application provides a technique capable of estimating a deposition state of a pump early and easily.

[0009] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS

[0010] According to one embodiment of the present application, a deposition state monitoring method which monitors a deposition state of deposits deposited in a pump connected to a processing container of a substrate processing apparatus which processes a substrate, includes: a step a of acquiring a current value of a motor which rotates a rotating structure of the pump; a step b of causing a damped waveform to occur in a temporal change of the current value by supplying a processing gas to the processing container; a step c of acquiring a peak current value of a plurality of peak portions constituting the damped waveform and a valley current value of a plurality of valley portions of the same number as the plurality of peak portions; a step d of calculating an estimated convergence current value at which the damped waveform converges by taking an average of the peak current values of the plurality of peak portions and the valley current values of the plurality of valley portions; and a step e of estimating the deposition state of the deposits based on the estimated convergence current value.

[0011] EFFECTS OF THE INVENTION

[0012] According to one embodiment, it is possible to early and easily estimate the deposition state of the pump. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a cross-sectional view schematically showing an example of a substrate processing apparatus according to one embodiment.

[0014] Figure 2 is a cross-sectional view schematically showing a turbo molecular pump provided in the substrate processing apparatus.

[0015] Figure 3 is a module diagram showing functional modules of a control unit that estimates the deposition state of the turbo molecular pump.

[0016] Figure 4 is a chart illustrating motor current data stored in a storage area.

[0017] Figure 5 is an explanatory diagram showing a process of calculating an average value from the motor current data.

[0018] Figure 6 is a flowchart showing a processing flow of a deposition state monitoring method.

[0019] BRIEF DESCRIPTION OF DRAWINGS

[0020] 1 substrate processing apparatus

[0021] 10 processing container

[0022] 54 turbo molecular pump

[0023] 543 rotating structure

[0024] 549 motor

[0025] 101 first peak portion

[0026] 102 first valley portion

[0027] 103 second peak portion

[0028] 104 second valley portion DETAILED DESCRIPTION

[0029] Hereinafter, with reference to the drawings, a mode for carrying out the present application will be described. In each drawing, the same reference numerals are assigned to the same components, and repeated description will be omitted.

[0030] Figure 1 is a cross-sectional view schematically showing an example of a substrate processing apparatus 1 according to one embodiment. As shown in FIG. 1, the substrate processing apparatus 1 includes a processing container 10, a turbo molecular pump 54, and a control unit 50. Figure 1As shown, the substrate processing apparatus 1 is an inductive coupled plasma (ICP) processing apparatus that performs various substrate processes on a substrate (hereinafter, simply referred to as a substrate G) for an FPD formed of a glass material. The FPD manufactured by processing the substrate G can be exemplified by a liquid crystal display (LCD), an electroluminescence (EL), a plasma display panel (PDP), or the like. In addition, as the material of the substrate G, a synthetic resin or the like can be applied in addition to glass.

[0031] The substrate G can be any of a substrate on which a circuit is patterned on a surface, or a support substrate that does not have a circuit, or the like. The planar size of the substrate G can be, for example, a range of 1800 mm to 3400 mm in a long side and a range of 1500 mm to 3000 mm in a short side. In addition, the thickness of the substrate G can be, for example, a range of 0.2 mm to 4.0 mm. The substrate process performed by the substrate processing apparatus 1 can be exemplified by a film formation process using a CVD (Chemical Vapor Deposition) method, an etching process, or the like. Hereinafter, the substrate processing apparatus 1 that performs a film formation process as a substrate process will be described as an example.

[0032] The substrate processing apparatus 1 has a processing container 10 that is a box-shaped rectangular parallelepiped. The processing container 10 is formed of a metal such as aluminum or an aluminum alloy. In addition, the processing container 10 can be formed in an appropriate shape according to the shape of the substrate G, and for example, in a case where the substrate G is a circular plate or an elliptical plate, the processing container 10 is preferably formed in a cylindrical shape or an elliptical cylindrical shape, or the like.

[0033] The processing container 10 has a rectangular-shaped support frame 11 that protrudes to the inside of the processing container 10 at a prescribed position in the vertical direction, and a dielectric plate 12 is supported by the support frame 11 in the horizontal direction. The processing container 10 is divided into an upper chamber 13 and a lower chamber 14 by the dielectric plate 12. The upper chamber 13 is formed with an antenna chamber 13a on the inside. The lower chamber 14 accommodates the substrate G, and is formed with an internal space 14a on the inside where a substrate process is performed.

[0034] A side wall 15 of the lower chamber 14 has a transfer inlet / outlet port 17 that is opened and closed by a gate 16. The substrate processing apparatus 1 performs transfer of the substrate G in and out via the transfer inlet / outlet port 17 by a conveyance device not shown when the gate 16 is open.

[0035] Further, the side walls 15 of the lower chamber 14 are grounded (connected to the ground potential) via a ground line 18. The four-directional side walls 15 of the lower chamber 14 have, at the upper end, a seal groove 19 which is wound in an endless manner. The inside space 14a of the support frame 11 and the lower chamber 14 are hermetically sealed by a seal member 20, such as an O-ring, disposed in the seal groove 19.

[0036] The support frame 11 is formed of a metal such as aluminum or an aluminum alloy. Further, the dielectric plate 12 is formed of a ceramic such as alumina (AI2O3) or quartz.

[0037] On the inner side of the support frame 11, a shower head 21 for releasing a processing gas to the inside space 14a, which is composed of a plurality of long members, is provided in connection with the support frame 11 and serves as a support beam for supporting the dielectric plate 12. The dielectric plate 12 is supported on the upper surface of the shower head 21. The shower head 21 is formed of a metal such as aluminum and is preferably subjected to a surface treatment based on anodic oxidation. Inside the shower head 21, a gas flow path 21a is formed in the horizontal direction. Further, the shower head 21 has a plurality of gas release holes 21b which communicate the gas flow path 21a with the lower surface of the shower head 21 (the inside space 14a).

[0038] A gas introduction pipe 22 which communicates with the gas flow path 21a is connected to the upper surface of the shower head 21. The gas introduction pipe 22 extends upward in the upper chamber 13 and penetrates the upper chamber 13, and is connected to a gas supply portion 23 provided outside the processing vessel 10.

[0039] The gas supply portion 23 has a gas supply path 24 which is combined with the gas introduction pipe 22, and has, in order from the upstream to the downstream of the gas supply path 24, a gas supply source 25, a mass flow controller 26, and an on-off valve 27. In the film formation processing, a processing gas is supplied from the gas supply source 25, the flow rate is controlled by the mass flow controller 26, and the supply timing is controlled by the on-off valve 27. The processing gas flows from the gas supply path 24 through the gas introduction pipe 22 into the gas flow path 21a, and is released to the inside space 14a through the gas release holes 21b.

[0040] A high-frequency antenna 28 is provided in the upper chamber 13 which forms an antenna chamber 13a. The high-frequency antenna 28 is composed by arranging an antenna wire formed of a conductive metal such as copper in a loop shape or a spiral shape. Alternatively, the high-frequency antenna 28 can be a structure in which loop-shaped antenna wires are provided in multiple layers. A power supply member 29 which extends upward in the upper chamber 13 is connected to the terminal of the high-frequency antenna 28.

[0041] The power supply part 29 has an upper end protruding to the outside of the processing container 10, and a high-frequency power supply part 30 is connected to the upper end. The high-frequency power supply part 30 has a power supply line 30a connected to a high-frequency power source 32 via a matcher 31 that performs impedance matching. The high-frequency power source 32 applies high-frequency power of a frequency (for example, 13.56 MHz) corresponding to the processing of the substrate to the high-frequency antenna 28. Thereby, the high-frequency antenna 28 forms an induction electric field in the lower chamber 14.

[0042] Further, the processing container 10 has a stage 40 (mounting stage) that mounts the substrate G fed from the feeding and discharging port 17 in the lower chamber 14. The stage 40 has a stage main body 41, a stage base 42, a plurality of lift pins 43, and a plurality of lift pin lift mechanisms 44. The substrate G fed into the lower chamber 14 is handed over to each lift pin 43 that has been lifted by each lift pin lift mechanism 44, and is mounted on the stage main body 41 by lowering each lift pin 43.

[0043] The stage main body 41 is formed in a rectangular shape in plan view, and has a mounting surface 411 of the same degree of planar size as the substrate G. For example, the planar size of the mounting surface 411 is in a range of 1800 mm to 3400 mm in the long side and in a range of 1500 mm to 3000 mm in the short side.

[0044] Between the mounting surface 411 of the stage main body 41 and the shower head 21, a plasma processing space PCS is formed. In the plasma processing space PCS, plasma is generated by plasma-izing the processing gas supplied from the shower head 21 to the internal space 14a by the induction electric field formed by the high-frequency antenna 28. The substrate processing apparatus 1 deposits a film formation precursor in the plasma generated in the plasma processing space PCS on the substrate G. Further, instead of the dielectric plate 12, a metal plate can be used, the induction electric field is formed via the metal plate, and the plasma is generated, in which case, the support beam is not needed, and the metal plate can serve as the shower head.

[0045] Further, the stage main body 41 is formed of aluminum, an aluminum alloy, or the like, and has a temperature adjustment mechanism that adjusts the temperature of the substrate G. For example, the temperature adjustment mechanism has a heating wire 45 as a resistance body in the stage main body 41, and has a temperature adjustment power supply part 46 that supplies power to the heating wire 45 outside the processing container 10. Alternatively, the temperature adjustment mechanism can include a flow path that circulates a refrigerant inside the stage main body 41 and a cooler (not shown) that supplies the refrigerant to the flow path. For example, the substrate processing apparatus 1 adjusts the temperature of the mounting surface 411 of the stage 40 to 200°C or the like and maintains the temperature state by heating the heating wire 45 when the substrate processing (film formation processing) is performed. Further, the substrate G can be heated by circulating a heated temperature adjustment medium in the flow path.

[0046] The pedestal 42 is formed of an insulating material, is disposed on the bottom wall 33 of the lower chamber 14, and supports the table body 41. The pedestal 42 has an opening in the bottom portion, and fixes and supports the table body 41 in a state in which the table body 41 is spaced apart from the bottom wall 33. The pedestal 42 can also have a configuration in which a lower portion member that supports the table body 41 and an upper portion member that surrounds the side surface of the table body 41 are separable. Further, the table 40 has a not-shown bias power supply portion that supplies high-frequency power for forming a bias for introducing plasma to the table 40 side at the time of substrate processing.

[0047] Further, the substrate processing apparatus 1 has an exhaust port 33a that exhausts the gas in the internal space 14a in the bottom wall 33 of the processing container 10, and has an exhaust portion 50 that is connected to the processing container 10 via the exhaust port 33a. In addition, in the Figure 1 In the above embodiment, one exhaust port 33a and one exhaust portion 50 are exemplified, but the substrate processing apparatus 1 can have exhaust ports 33a and exhaust portions 50 at a plurality of locations.

[0048] The exhaust port 33a is formed in a circular shape, and is disposed between the side wall 15 of the processing container 10 and the table 40. The diameter of the exhaust port 33a depends on the size of the processing container 10, and is preferably set in a range of 200 mm to 400 mm, for example, and is set to 300 mm in the present embodiment. Further, the shape of the exhaust port 33a can not be a circular shape, and can be formed in a semicircular shape or the like corresponding to the disposition position.

[0049] In addition, the substrate processing apparatus 1 has a plurality of buffer plates 34 at the outer periphery of the table 40 and between the plasma processing space PCS and the exhaust port 33a. Each buffer plate 34 imparts electrical conduction to the processing gas around the table 40 to guide the exhaust direction. In addition, the buffer plate 34 (and the side wall 15 of the lower chamber 14) is connected to a ground potential, and functions as a counter electrode with respect to the high-frequency power for bias.

[0050] The exhaust portion 50 includes an exhaust pipe 51 that is connected to the exhaust port 33a, and an exhaust mechanism 52 that is provided to the exhaust pipe 51 and exhausts the processing gas (processing gas that does not have a step of processing a substrate) in the processing container 10. In addition, the exhaust portion 50 can have an exhaust mesh 35 for preventing components from falling at the connection portion (or the exhaust port 33a) of the processing container 10 and the exhaust pipe 51.

[0051] The exhaust mechanism 52 depressurizes the internal space 14a of the processing container 10 by exhaust. In addition, the exhaust mechanism 52 exhausts reaction products (deposits) generated in the substrate processing together with the processing gas. Specifically, in the exhaust mechanism 52, there are sequentially provided, to the downstream side of the flow direction of the processing gas to the exhaust pipe 51, an APC (Automatic Pressure Control) valve 53, a turbo molecular pump (TMP) 54, and a dry pump 55. The exhaust mechanism 52 rough-pumps the inside of the processing container 10 by the dry pump 55, and then evacuates the inside of the processing container 10 by the turbo molecular pump 54. In addition, the exhaust mechanism 52 controls the pressure of the internal space 14a by adjusting the opening degree of the APC valve 53.

[0052] Each of the components of the exhaust mechanism 52 (the APC valve 53, the turbo molecular pump 54, and the dry pump 55) is controlled in operation by the control section 60. The control section 60 is a control computer having one or more processors 61, a memory 62, an input-output interface not shown, and electronic circuits. In addition, in the control section 60, there is connected a user interface 65 capable of notifying information of the substrate processing apparatus 1 and inputting information by a user.

[0053] The processor 61 is composed of one or more of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), a circuit composed of a plurality of discrete semiconductor elements, and the like. The memory 62 is composed of an appropriate combination of a volatile memory, a non-volatile memory (for example, an optical disk, a DVD (Digital Versatile Disc), a hard disk, a flash memory, and the like). In addition, the user interface 65 can use a monitor, a speaker, an alarm lamp, a keyboard, a mouse, a touch panel, and the like.

[0054] The memory 62 stores a program for operating the substrate processing apparatus 1, a recipe of a processing condition of the substrate processing, and the like. The processor 61 controls each of the components of the substrate processing apparatus 1 by reading and executing the program of the memory 62. For example, in the control of the turbo molecular pump 54, the control section 60 calculates a target rotational speed of a motor 549 of the turbo molecular pump 54, and outputs the calculated target rotational speed to the driver 56 so that the pressure in the processing container 10 becomes a target pressure (refer to FIG. 6). Figure 2). Thus, the driver 56 supplies power corresponding to the target rotational speed to the motor of the turbomolecular pump 54, thereby controlling the drive of the turbomolecular pump 54.

[0055] Figure 2 is a cross-sectional view schematically showing the turbomolecular pump 54 provided in the substrate processing apparatus 1. The turbomolecular pump 54 is configured in such a manner that a base 541 and a housing 542 are fixed to each other, and a rotating structure 543 is housed in a space inside thereof. The rotating structure 543 has an umbrella-shaped pump rotor 544 and a rotating shaft 545 that supports the center of rotation of the pump rotor 544.

[0056] On the outer peripheral surface of the pump rotor 544 on the side of the housing 542, a plurality of rotating vanes 544a are formed that project in a direction orthogonal to the axial direction of the rotating shaft 545 (radial direction outside). On the other hand, on the inner peripheral surface of the housing 542, a plurality of fixed vanes 542a are formed that are respectively arranged between adjacent rotating vanes 544a. The rotating vanes 544a and the fixed vanes 542a constitute a turbopump region that draws in gas via an opening of the housing 542.

[0057] In addition, on the side of the base 541 of the pump rotor 544, a cylindrical portion 544b having a helical groove on the outer peripheral surface is formed. On the other hand, the inner peripheral surface of the base 541 opposite to the cylindrical portion 544b is sufficiently close to the cylindrical portion 544b, so as to narrow the flow path of gas. The cylindrical portion 544b and the inner peripheral surface of the base 541 constitute a helical pump region that guides the gas of the turbopump region to an exhaust port 546 of the base 541.

[0058] The rotating shaft 545 of the rotating structure 543 is non-contact supported by a plurality of magnetic bearings 547 provided to the base 541. Each magnetic bearing 547 has an electromagnet and a displacement sensor, and the floating position of the rotating shaft 545 is detected by the displacement sensor. In addition, the turbomolecular pump 54 has a rotation sensor 548 that detects the number of rotations (number of rotations per 1 second) of the rotating shaft 545 in the base 541.

[0059] Furthermore, the base 541 and the rotating shaft 545 have a motor 549 that rotationally drives the rotating shaft 545. The motor 549 is formed of a motor stator 549a on the side of the base 541 and a motor rotor 549b on the side of the rotating shaft 545. With this motor 549, the rotating structure 543 is rotated at high speed around the axis of the rotating shaft 545. Thus, the pump rotor 544 can guide the gas on the opening side in the order of the turbopump region and the helical pump region, and discharge it from the exhaust port 546.

[0060] The driver 56 receives an instruction of a target rotational speed from the control section 60, and adjusts the power supplied to the motor 549. At this time, the driver 56 detects the actual rotational speed using the rotational sensor 548 and performs feedback control, whereby the motor 549 rotates so that the actual rotational speed substantially coincides with the target rotational speed. In addition, the control section 60 monitors the actual current of the turbomolecular pump 54 by receiving information of the actual current supplied to the motor 549 from the driver 56 or the current sensor 57 provided to the wiring. Then, the control section 60 estimates the deposition state of the reaction product (deposits) deposited in the turbomolecular pump 54 on the basis of the information of the actual current.

[0061] Figure 3 is a module diagram showing a functional module of the control section 60 that estimates the deposition state of the turbomolecular pump 54. As shown in Figure 3 , the pump control section 70, the current acquisition section 71, the storage area 72, the gas control section 73, and the deposition state estimation section 74 are formed inside the control section 60.

[0062] The pump control section 70 issues an instruction of a target rotational speed at which the processing gas is exhausted to the driver 56, so that the inside of the processing container 10 becomes a reduced-pressure atmosphere set in the scheme of the substrate processing. Thereby, the driver 56 supplies appropriate power to the motor 549 of the turbomolecular pump 54, and the rotating structure 543 rotates at substantially constant target rotational speed. In addition, during the substrate processing, the turbomolecular pump 54 continuously operates to maintain the prescribed reduced-pressure atmosphere in the processing container 10.

[0063] The current acquisition section 71 acquires information of the actual current from the driver 56 or the current sensor 57, and stores motor current data D in which time information counted in the control section 60 is associated with the information of the actual current in the storage area 72. The storage area 72 is provided in one area in the memory 62.

[0064] The gas control section 73 controls the operation of the gas supply section 23, and supplies the processing gas to the inside of the processing container 10. In addition, the gas control section 73 outputs information of the supply state of the processing gas to the deposition state estimation section 74. As the supply state of the processing gas, for example, the timing of the start of the supply, the kind of the processing gas, the supply amount (flow rate), and the like can be exemplified.

[0065] The deposition state estimation section 74 estimates the deposition state of the deposits in the turbomolecular pump 54 on the basis of the current supplied to the motor 549 of the turbomolecular pump 54. Therefore, the deposition state estimation section 74 has a current analysis section 75 that analyzes the motor current data D, an estimation section 76 that estimates the deposition state on the basis of the analysis result of the current analysis section 75, and a notification control section 77 that urges maintenance or the like to the user on the basis of the estimation result.

[0066] The current analysis section 75 reads the motor current data D stored in the storage region 72, and extracts and processes information necessary for estimation of the deposition state from the motor current data D. Specifically, the current analysis section 75 reads the motor current data D at the timing at which the supply of the processing gas is started, based on the information of the supply state of the processing gas from the gas control section 73. That is, in the estimation of the deposition state, a larger current value at the time when the load is applied to the turbo molecular pump 54 by the introduction of the processing gas into the processing container 10 is used in order to improve the estimation accuracy.

[0067] Figure 4 is a graph illustrating the motor current data D stored in the storage region 72. In Figure 4 the graph of, the horizontal axis is time, and the vertical axis is the current value or the flow rate of the processing gas. As Figure 4 indicated, the motor current data D sharply rises in the current value at the time when the supply of the processing gas is started, with some time difference. This is because the flow rate of the processing gas in the processing container 10 increases along with the supply of the processing gas, and thus the flow rate of the processing gas to be exhausted also increases, and the load applied to the turbo molecular pump 54 that sucks the processing gas also becomes large. In addition, the motor current data D after the current value sharply rises is formed as a decaying waveform in which the current value gradually converges while repeatedly repeating the amplitudes of the decrease and increase with the passage of time.

[0068] Further, Figure 4 the peak (the topmost portion) of each peak portion and the bottom (the bottommost portion) of each valley portion of the decaying waveform of the motor current data D of Figure 4 become flat. This is because the current value is detected in the driver 56 or the current sensor 57 of the turbo molecular pump 54 at a prescribed sampling period. That is,

[0069] the sampling period of the actual current in the driver 56 or the current sensor 57 is set to a time interval shorter than the half period of the decaying waveform of the motor current data D. The sampling period is preferably set to an appropriate time interval by performing experiments, simulations in advance. For example, as the sampling period, it can be set to a range of 1 sec to 10 sec, for example.

[0070] As already described above, the current analysis section 75 uses the motor current data D at the time when the current value rises in conjunction with the supply of the processing gas to the processing container 10. Here, since the motor current data D depicts an attenuation waveform that repeatedly has an amplitude at the timing when the supply of the processing gas starts, if the current value after the attenuation waveform converges is to be extracted, time is required until the extraction. For example, it takes about 90 seconds for the motor current to stabilize to a stable plateau waveform (i.e., a fixed value) after the supply of the processing gas starts. However, in the substrate processing in the substrate processing apparatus 1, there are few steps in which the processing gas is continuously supplied at the same flow rate into the processing container 10 for 90 seconds or more. If the flow rate of the processing gas is changed before the attenuation waveform of the motor current data D converges, an undesirable situation occurs in which the current value in the stable waveform cannot be obtained. The same is true not only for the flow rate, but also in the case where a condition such as the type of the processing gas is changed.

[0071] Therefore, the substrate processing apparatus 1 of the present embodiment is configured to predict the current value at which the attenuation waveform converges even during the period of the unstable attenuation waveform of the motor current data D. Specifically, the current analysis section 75 extracts two points with respect to the peak current value and the trough current value of the amplitude in the attenuation waveform at the timing when the supply of the processing gas starts, and calculates the average value using the current values of the total of four points.

[0072] Figure 5 is a diagram showing the process of calculating the average value from the motor current data D. As shown in Figure 5 the attenuation waveform of the motor current data D oscillates in the order of the first peak portion 101, the first trough portion 102, the second peak portion 103, the second trough portion 104, the third peak portion 105, the third trough portion 106, and so on along the time elapse direction. Also, when only the peak portions of the motor current data D are focused on, the current value of the attenuation waveform basically decreases in the order of the peak of the first peak portion 101, the peak of the second peak portion 103, the peak of the third peak portion 105, and so on. However, the driver 56 or the current sensor 57 detects the current for each sampling period regardless of the timing when the supply of the processing gas starts, and thus there are cases where the order of the height (current value) of the peak between adjacent peak portions differs from each other depending on the timing of the sampling. Similarly, when only the trough portions of the motor current data D are focused on, the current value of the attenuation waveform basically increases in the order of the trough of the first trough portion 102, the trough of the second trough portion 104, the trough of the third trough portion 106, and so on. However, the order of the height (current value) of the peak between adjacent trough portions also differs from each other depending on the timing of the sampling.

[0073] The current analysis section 75 of the present embodiment extracts only the peak current values of the 2 peak portions (first peak portion 101, second peak portion 103) and the valley bottom current values of the 2 valley portions (first valley portion 102, second valley portion 104) after the decay waveform of the motor current data D has just started. The first peak portion 101 is a wave at the time when the current value initially rises greatly in conjunction with the start of the supply of the processing gas. The first valley portion 102 is a wave adjacent to and continuous with the first peak portion 101 and at which the current value greatly decreases with respect to the first peak portion 101. The second peak portion 103 is a wave adjacent to and continuous with the first valley portion 102 and at which the current value greatly rises with respect to the second valley portion 104. The second valley portion 104 is a wave adjacent to and continuous with the second peak portion 103 and at which the current value greatly decreases with respect to the second peak portion 103.

[0074] Further, the current analysis section 75 calculates an average value (hereinafter, also referred to as an estimated convergence current value ES) from the 4 extracted current values, and regards the estimated convergence current value ES as the current value at the time of convergence of the decay waveform. Furthermore, the calculation of the average value based on the 4 extracted current values can be an arithmetic average, or can also be a geometric average.

[0075] Here, with respect to the decay waveform of the current value of the turbo molecular pump 54, the present applicant has confirmed that the estimated convergence current value ES obtained by averaging the peak current values of a plurality of peak portions and the valley bottom current values of the same number of valley portions is approximately the current value after the convergence of the decay waveform, through repeated experiments. That is, the decay waveform of the current of the turbo molecular pump 54 in conjunction with the start of the supply of the processing gas is said to oscillate up and down with the current value after the convergence as a reference, because the load applied to the turbo molecular pump 54 is balanced with the reaction force (torque) applied by the driver to suppress the load. Therefore, the estimated convergence current value ES obtained by averaging the peak current values of a plurality of peak portions and the valley bottom current values of the same number of valley portions represents the current value after the convergence of the decay waveform with sufficient accuracy. For example, even in the case where the sampling period of the current value is shifted and the peak current value of the first peak portion 101 becomes lower than the peak current value of the second peak portion 103, approximately the same estimated convergence current value ES can be obtained. This is because, in conjunction with the matching of the peak current value of the first peak portion 101 and the peak current value of the second peak portion 103, the valley bottom current value of the first valley portion 102 becomes higher than the valley bottom current value of the second valley portion 104, and as a result, the average value is approximately the estimated convergence current value ES.

[0076] In addition, regarding the timing of the calculation of the estimated convergence current value ES, the current analysis section 75 uses the timing immediately after the peak current value of the set two peak portions and the valley current value of the two valley portions have been acquired. For example, if the current acquisition section 71 acquires the current value before the third peak portion 105, it becomes a state in which the peak current value of two peak portions of the decay waveform and the valley current value of two valley portions can be extracted. Therefore, the current analysis section 75 calculates the estimated convergence current value ES immediately from the four current values up to the timing of the acquisition of the current value of the third peak portion 105, and thereby can obtain the estimated convergence current value ES that approximates the current value after the decay waveform converges in a sufficiently short time.

[0077] In addition, the number of peak portions from which the peak current value is extracted in the decay waveform is not limited to two, and can be three or more if the conditions of the process gas such as the flow rate are changed before. Of course, the number of valley portions from which the valley current value is extracted is not limited to two, and can be the same number as the number of peak portions. The more the number of peak portions and the number of valley portions from which the estimated convergence current value ES is calculated, the more the estimated convergence current value ES that approximates the current value after the decay waveform converges can be expected. In addition, the current analysis section 75 can acquire the estimated convergence current value ES using each of the peak current values of the second peak portion 103 and the third peak portion 105 and each of the valley current values of the second valley portion 104 and the third valley portion 106, for example, without using the peak portion and the valley portion immediately after the decay waveform starts. Alternatively, the current analysis section 75 can monitor the decay waveform of the motor current data D, exclude the peak portion or the valley portion in which an abnormal amplitude has occurred, and then calculate the estimated convergence current value ES. For example, in the case where the peak current value of the second peak portion 103 is abnormally low, the current analysis section 75 can not extract the second peak portion 103 and the second valley portion 104, and use each of the peak current values of the first peak portion 101 and the third peak portion 105 and each of the valley current values of the first valley portion 102 and the third valley portion 106. Also, in the case where the value of the first peak portion 101 is much larger than a prescribed value (a past acquired current value), the current analysis section 75 can calculate the estimated convergence current value ES using the valley current value of the first valley portion 102, the peak current value of the second peak portion 103, the valley current value of the second valley portion 104, and the peak current value of the third peak portion 105.

[0078] Return Figure 3The estimation unit 76 estimates the deposition state of the deposits in the turbomolecular pump 54 based on the flow rate of the processing gas acquired from the gas control unit 73 and the estimated convergence current value ES calculated by the current analysis unit 75. As for the deposition state, the amount of the deposits in the turbomolecular pump 54 can be a numerical value or a value further converted into the continuous operation period of the pump or the like. For example, the control unit 60 stores in the storage region 72 mapping information or a function obtained by correlating the flow rate of the processing gas and the estimated convergence current value ES with information on the deposition state of the deposits in the turbomolecular pump 54. Then, when the flow rate of the processing gas and the estimated convergence current value ES are received, the estimation unit 76 refers to the storage region 72 to extract or calculate the deposition state. As described above, since the estimated convergence current value ES approximates the current value after the decay waveform converges, the estimation unit 76 can estimate the deposition state of the turbomolecular pump 54 with high accuracy.

[0079] In addition, the notification control unit 77 outputs the state information of the turbomolecular pump 54 to the user interface 65 based on the deposition state estimated by the estimation unit 76 and notifies the user. For example, the notification control unit 77 displays the estimated deposition state (the amount of the deposits, the continuous operation period, the maintenance prediction time and date, or the like) as the state information of the turbomolecular pump 54 as it is on the display unit of the user interface 65. Alternatively, the notification control unit 77 can have a maintenance threshold value for comparison with the amount of the deposits, and in the case where the amount of the deposits is equal to or greater than the maintenance threshold value, the notification control unit 77 can perform notification urging the user to perform maintenance of the turbomolecular pump 54. Further, the estimated convergence current value ES itself can be processed as a numerical value indicating the deposition state, and for example, a maintenance threshold value can be set using the current value, and in the case where the estimated convergence current value ES is equal to or greater than the current value set as the maintenance threshold value, the notification control unit 77 can perform notification urging maintenance.

[0080] The substrate processing apparatus 1 of the present embodiment is basically a device configured as described above, and the following describes the operation (deposition state monitoring method) thereof with reference to Figure 6 the flowchart of FIG. 8. Figure 6 the flowchart of FIG. 8.

[0081] As a preparation for substrate processing, the control unit 60 of the substrate processing apparatus 1 first opens the gate 16 and uses the conveyance device to deliver the substrate G into the internal space 14a via the delivery / discharge port 17. Then, the control unit 60 raises each lift pin 43 of the lift pin lift mechanism 44 and receives the substrate G from the conveyance device, and lowers each lift pin 43 after the conveyance device is retracted to place the substrate G on the placement surface 411 of the table 40.

[0082] After the substrate G is placed, the control unit 60 of the substrate processing apparatus 1 begins substrate processing, and correspondingly starts the deposition state monitoring method. The control unit 60 first activates the exhaust mechanism 52 of the exhaust unit 50 to exhaust the gas from the internal space 14a of the processing container 10. At this time, the pump control unit 70 of the control unit 60 sends a command to the driver 56 to reduce the pressure of the processing container 10 to a predetermined internal pressure by a target rotation number. This causes the turbomolecular pump 54 (motor 549) to rotate under the current adjustment of the driver 56 (step S1). The motor 549 is continuously controlled to rotate by the driver 56 in a manner that maintains the target rotation number.

[0083] During the rotational drive of the turbomolecular pump 54, the driver 56 or the current sensor 57 detects the actual current supplied from the driver 56 to the motor 549. Furthermore, the current acquisition unit 71 of the control unit 60 acquires the actual current sent from the driver 56 or the current sensor 57 (step S2).

[0084] When the internal space 14a of the processing container 10 becomes a predetermined reduced pressure atmosphere, the gas control unit 73 controls the gas supply unit 23 to supply processing gas into the processing container 10 (step S3). As a result, the flow rate of the processing gas inside the processing container 10 increases sharply (see reference). Figure 5 At time point t0, the processing gas is ejected into the plasma processing space PCS through the gas release port 21b of the spray head 21. Accompanying the ejection of the processing gas, the substrate processing apparatus 1 supplies high-frequency power, for example 13.56 MHz, from the high-frequency power supply 32 to the high-frequency antenna 28, thereby forming a uniform induced electric field within the plasma processing space PCS via the dielectric plate 12. Using this induced electric field, the processing gas is plasma-enhanced in the plasma processing space PCS, generating a high-density inductively coupled plasma. As a result, the substrate processing apparatus 1 is able to perform substrate processing (film formation processing) on ​​the substrate G to form a predetermined film.

[0085] In addition, the processing gas supplied to the plasma processing space PCS that does not contribute to the processing of the substrate, as well as the reaction products and by-products (deposits) generated by the substrate processing, are attracted by the exhaust section 50 and thus exhausted from the exhaust port 33a through the exhaust pipe 51.

[0086] Based on the supply of the processing gas into the processing container 10 in the substrate processing, the current acquisition section 71 of the control section 60 acquires the actual current of the decay waveform in which the amplitude is repeated after the motor current sharply rises. The deposition state estimation section 74 reads and monitors the motor current data D after the timing at which the supply of the processing gas is received from the gas control section 73. Then, the current analysis section 75 of the deposition state estimation section 74 extracts the peak current value of the two peak portions (the first peak portion 101, the second peak portion 103) and the valley current value of the two valley portions (the first valley portion 102, the second valley portion 104) from the motor current data D (step S4).

[0087] When the current analysis section 75 acquires the peak current value of the set number (two) of the peak portions and the valley current value of the same number (two) of the valley portions, the estimation convergence current value ES is calculated by taking an average thereof (step S5). For example, the current analysis section 75 immediately calculates the estimation convergence current value ES after the set number of the current values are acquired (refer to the timing t1 in FIG. 6). Figure 5

[0088] Then, the estimation section 76 estimates the deposition state of the deposits of the turbomolecular pump 54 based on the flow rate of the processing gas and the calculated estimation convergence current value ES (step S6). Thereby, the estimation section 76 can estimate the deposition state of the deposits of the turbomolecular pump 54 with high accuracy before the decay waveform converges. Therefore, the control section 60 can recognize the deposition state of the turbomolecular pump 54 well before the flow rate of the processing gas and the like in the substrate processing is changed (refer to the timing t2 in FIG. 6). Figure 5

[0089] In addition, the estimation section 76 compares the estimated amount of the deposits with a maintenance threshold value, and determines whether or not the turbomolecular pump 54 needs to be maintained (step S7). The estimation section 76 proceeds to step S8 in a case where the amount of the deposits is equal to or greater than the maintenance threshold value (step S7: YES), and skips step S8 in a case where the amount of the deposits is less than the maintenance threshold value (step S7: NO).

[0090] In step S8, the notification control section 77 notifies the user of information that urges the maintenance of the turbomolecular pump 54 via the user interface 65. Thereby, the user can perform the maintenance of the turbomolecular pump 54 at an appropriate timing.

[0091] ​​As described above, the substrate processing apparatus 1 and the deposition state monitoring method of the present embodiment use the decay waveform of the current value supplied to the motor 549 of the turbomolecular pump 54 to estimate the deposition state of the deposition of the deposition material to the turbomolecular pump 54. Therefore, the control section 60 can estimate the deposition state in a short time from the start of the supply of the processing gas to the processing container 10. For example, even if the flow rate of the processing gas is varied depending on the substrate processing, the control section 60 can stably and highly accurately perform the estimation of the deposition state.

[0092] Hereinafter, the technical idea and effects of the present application described in the above embodiments are described.

[0093] The first aspect of the present application is a deposition state monitoring method that monitors a deposition state of a deposition material deposited on a pump (turbomolecular pump 54) connected to a processing container 10 of a substrate processing apparatus 1 that processes a substrate G, the deposition state monitoring method including: a step a of acquiring a current value of a motor 549 that rotates a rotating structure 543 of the pump; a step b of causing a decay waveform to occur in a time variation of the current value by supplying a processing gas to the processing container 10; a step c of acquiring a peak current value of a plurality of peak portions (first peak portion 101, second peak portion 103) constituting the decay waveform and a valley current value of a plurality of valley portions (first valley portion 102, second valley portion 104) of the same number as the plurality of peak portions; a step d of calculating an estimated convergence current value ES at which the decay waveform converges by taking an average of the peak current values of the plurality of peak portions and the valley current values of the plurality of valley portions; and a step e of estimating the deposition state of the deposition material based on the estimated convergence current value ES.

[0094] According to the above, the deposition state monitoring method calculates the estimated convergence current value ES using the decay waveform of the current value of the pump (turbomolecular pump 54), whereby the deposition state of the pump can be estimated early and easily. That is, the estimated convergence current value ES, which is an average of the plurality of peak portions (first peak portion 101, second peak portion 103) and the plurality of valley portions (first valley portion 102, second valley portion 104) of the decay waveform, sufficiently approximates the current value after the convergence of the decay waveform. Therefore, the deposition state monitoring method can estimate the deposition state substantially the same as the current value after the convergence without waiting for the convergence of the decay waveform, for example, and can grasp the deposition state well before the flow rate of the processing gas is changed in the substrate processing.

[0095] In addition, in the step c, the peak current values of the plurality of peak portions (first peak portion 101, second peak portion 103) and the valley current values of the plurality of valley portions (first valley portion 102, second valley portion 104) immediately after the start of the decay waveform are extracted. Thereby, the deposition state monitoring method can estimate the deposition state without taking time after the supply of the processing gas to the processing container 10 and the occurrence of the decay waveform in the current value.

[0096] Further, step d is performed immediately after the peak current values of the set number of peak portions (first peak portion 101, second peak portion 103) and the bottom current values of the valley portions (first valley portion 102, second valley portion 104) are acquired. Thus, the deposition state monitoring method can estimate the deposition state immediately after the number of the peak portions and the valley portions are repeatedly specified, and can further shorten the time taken for the estimation.

[0097] Further, in step c, the peak current values of the two peak portions (first peak portion 101, second peak portion 103) and the bottom current values of the two valley portions (first valley portion 102, second valley portion 104) immediately after the decay waveform starts are extracted. Thus, the deposition state monitoring method can estimate the deposition state in a shorter time after the processing container 10 is supplied with the processing gas.

[0098] Further, in step c, the bottom current values of the valley portions (first valley portion 102, second valley portion 104) adjacent to the peak portions (first peak portion 101, second peak portion 103) of which the peak current values have been acquired are acquired. Thus, the deposition state monitoring method can calculate the estimated convergence current value ES with higher accuracy.

[0099] Further, step f is included, which judges whether maintenance of the pump (turbo molecular pump 54) is required based on the deposition state of the deposit estimated in step e. Thus, the deposition state monitoring method can appropriately notify the user of the timing of maintenance of the pump based on the estimated deposition state.

[0100] Further, the pump (turbo molecular pump 54) is connected to the processing container 10 to perform evacuation of the internal space 14a of the processing container 10, and thus the processing gas supplied to the internal space 14a is introduced into the inside of the pump. Thus, even if the reaction product (deposit) generated in the processing container 10 is deposited in the structure of the pump that performs evacuation of the processing container, the deposition state monitoring method can stably monitor the deposition state of the pump.

[0101] Further, a second aspect of the present application is a substrate processing apparatus 1 that processes a substrate G, and has: a processing container 10 that processes the substrate G; a pump (turbomolecular pump 54) that is connected to the processing container 10 and performs exhaust of an internal space 14a of the processing container 10; and a control section 60 that controls the following steps: step a, acquires a current value of a motor 549 that rotates a rotating structure 543 of the pump; step b, causes a damped waveform to occur in a time change of the current value by supplying a processing gas to the processing container 10; step c, acquires a peak current value of a plurality of peak portions (first peak portion 101, second peak portion 103) that constitute the damped waveform and a valley current value of a plurality of valley portions (first valley portion 102, second valley portion 104) that are adjacent to the plurality of peak portions and are the same number as the plurality of peak portions; step d, calculates a presumed convergence current value ES at which the damped waveform converges by taking an average of the peak current value of the plurality of peak portions and the valley current value of the plurality of valley portions; and step e, presumes a deposition state of a deposit based on the presumed convergence current value ES. In this case, the substrate processing apparatus 1 can early and easily presume the deposition state of the pump.

[0102] The substrate processing apparatus 1 and the deposition state monitoring method of the embodiments disclosed herein are illustrative and not restrictive in all respects. The embodiments can be modified in various ways without departing from the scope of the appended claims and the spirit thereof. The contents described in the above-described embodiments can also be adopted in other configurations within a range where there is no contradiction, and can be combined with each other within a range where there is no contradiction.

[0103] The substrate processing apparatus 1 and the deposition state monitoring method of the present application can be applied to various types of apparatuses regardless of whether plasma is used in processing of a substrate. For example, it can be applied to any one of an Atomic Layer Deposition (ALD) apparatus, a Capacitively Coupled Plasma (CCP), an Inductively Coupled Plasma (ICP), a Radial Line Slot Antenna (RLSA), an Electron Cyclotron Resonance Plasma (ECR), and a Helicon Wave Plasma (HWP).

Claims

1. A deposition state monitoring method characterized by: the deposition state monitoring method monitoring a deposition state of a deposit deposited in a pump connected to a processing vessel of a substrate processing apparatus that processes a substrate, comprising: a step a of acquiring a current value of a motor that rotates a rotating structure of the pump; a step b of causing a damped waveform to occur in a time change of the current value by supplying a processing gas to the processing vessel; a step c of acquiring, in a period before the damped waveform converges, a peak current value of a plurality of peak portions constituting the damped waveform and a valley current value of a plurality of valley portions of the same number as the plurality of peak portions; a step d of calculating, before the damped waveform converges, a predicted convergence current value after the damped waveform converges by taking an average of the peak current value of the plurality of peak portions and the valley current value of the plurality of valley portions acquired; and a step e of predicting the deposition state of the deposit based on the predicted convergence current value.

2. The deposition state monitoring method according to claim 1, characterized in that: in the step c, the peak current value of the plurality of peak portions and the valley current value of the plurality of valley portions are extracted immediately after the damped waveform starts.

3. The deposition state monitoring method according to claim 2, characterized in that: the step d is performed immediately after the peak current value of the set number of peak portions and the valley current value of the valley portions are acquired.

4. The deposition state monitoring method according to claim 3, characterized in that: in the step c, the peak current value of 2 peak portions and the valley current value of 2 valley portions are extracted immediately after the damped waveform starts.

5. The deposition state monitoring method according to any one of claims 1 to 4, characterized in that: in the step c, the valley current value of the valley portion adjacent to the peak portion of which the peak current value has been acquired is acquired.

6. The deposition state monitoring method according to any one of claims 1 to 4, characterized by further comprising a step f of judging whether maintenance of the pump is required based on the deposition state of the deposit predicted in the step e.

7. The deposition state monitoring method according to any one of claims 1 to 4, characterized in that: the pump is connected to the processing vessel to perform exhaust of an inner space of the processing vessel, and thereby the processing gas supplied to the inner space is introduced into an inside of the pump, having: a processing vessel that processes the substrate; 8. A substrate processing apparatus for processing a substrate, characterized by comprising: a pump connected to the processing vessel to perform exhaust of an inner space of the processing vessel; and a control section, the control section controls the following steps: a step a of acquiring a current value of a motor that rotates a rotating structure of the pump; a step b of causing a damped waveform to occur in a time change of the current value by supplying a processing gas to the processing vessel; a step c of acquiring, in a period before the damped waveform converges, a peak current value of a plurality of peak portions constituting the damped waveform and a valley current value of a plurality of valley portions of the same number as the plurality of peak portions; ​ ​ Step d, calculating a presumed converged current value after the decay waveform converges by taking an average of the top peak current values of the plurality of the peak portions and the valley bottom current values of the plurality of the valley portions before the decay waveform converges; and Step e, presuming a deposition state of the deposit based on the presumed converged current value.

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