Sensor control method and computer-readable program

Abstract

This sensor control method for controlling a sensor in a substrate processing apparatus includes: the processes shown in steps S11 to S18; and, after step S18, if the absolute value of the difference between a second communication difference and a first communication difference is larger than a predetermined threshold (step S19), updating the first communication difference so as to be equal to the second communication difference (step S20), and returning to step S15 and performing steps S15 to S19; and, if the absolute value of the difference between the second communication difference and the first communication difference is equal to or less than the threshold (step S19), ending the update of the sensor time. This makes it possible for time synchronization of a sensor that is wirelessly connected to a substrate processing apparatus to be suitably performed.

Description

Sensor control method and computer-readable program

[0001] The present invention relates to a technology for controlling a sensor in a substrate processing apparatus. [Reference to related application] This application claims priority from Japanese Patent Application JP2024-165445, filed on 24 September 2024, and all disclosures of said application are incorporated herein.

[0002] Conventionally, in the manufacturing process of semiconductor substrates (hereinafter simply referred to as "substrates"), various processes are performed on the substrates using substrate processing equipment. Such substrate processing equipment is required to improve throughput and reduce the amount of chemicals used through process optimization, and in order to meet these requirements, it is necessary to measure the state of the substrate during processing. For measuring the state of the substrate during processing, for example, a process monitoring device disclosed in Japanese Patent No. 4813765 (Reference 1) is used. This process monitoring device is a wafer-type sensor that has substantially the same shape as a semiconductor wafer and is equipped with multiple sensors.

[0003] The measured values ​​of the substrate condition, obtained by the wafer-type sensor, are sent to the control unit of the substrate processing device via wireless communication such as Bluetooth®. In the control unit, the measured values ​​transmitted from the wafer-type sensor are compared with control signals that command the substrate processing device to operate, thereby obtaining the relationship between the substrate condition and the device condition of the substrate processing device.

[0004] Incidentally, in the control unit of the substrate processing apparatus, the measurement values ​​from the wafer-type sensor are recorded along with the reception time of the measurement, and are compared with the apparatus state of the substrate processing apparatus at the reception time. However, if a relatively large discrepancy occurs between the time when the measurement value (i.e., the substrate state) is actually acquired by the wafer-type sensor and the reception time due to delays in wireless communication, the substrate state and apparatus state at different times will be compared, and there is a risk that the correlation between the substrate state and the apparatus state cannot be obtained with high accuracy. Note that while reference 1 mentions synchronizing the clock in the process monitoring device with the clock related to the processing station, it does not describe the specific synchronization method.

[0005] The present invention aims to suitably synchronize the time of wirelessly connected sensors.

[0006] One aspect of the present invention is a sensor control method for controlling a sensor in a substrate processing apparatus, comprising: a) transmitting a device time, which is the internal time of the control unit of the substrate processing apparatus, from the control unit, receiving it at a sensor wirelessly connected to the control unit, and updating the sensor time, which is the internal time of the sensor, to the received device time; b) after step a), transmitting the sensor time from the sensor, receiving it as the received sensor time at the control unit, and obtaining the difference between the device time and the received sensor time as a first communication difference; c) after step b), transmitting a corrected device time from the control unit by adding 1 / 2 of the first communication difference to the device time; and d) after step c), transmitting the corrected device time to the sensor The process includes: e) receiving the sensor time and updating the sensor time to the correction device time; e) after step d), transmitting the sensor time from the sensor and receiving it as the correction sensor time at the control unit, and obtaining the time obtained by adding half of the first communication difference to the difference between the device time and the correction sensor time as the second communication difference; f) after step e), if the absolute value of the difference between the second communication difference and the first communication difference is greater than a predetermined threshold, updating the first communication difference to be equal to the second communication difference, returning to step c), and performing steps c) through e), and terminating the sensor time update if the absolute value of the difference between the second communication difference and the first communication difference is less than or equal to the threshold.

[0007] The present invention enables suitable time synchronization of wirelessly connected sensors.

[0008] Aspect 2 of the present invention is a sensor control method according to aspect 1, wherein the sensor is a substantially disc-shaped wafer-type sensor.

[0009] A third aspect of the present invention is a sensor control method according to aspect 1 or 2, wherein each time logging is performed by the sensor, steps a) through f) are performed before the start of logging, and the sensor time is updated.

[0010] Aspect 4 of the present invention is a computer-readable program for controlling a sensor in a substrate processing apparatus. When the program is executed on a computer, a) the device time, which is the internal time of the control unit of the substrate processing apparatus, is transmitted from the control unit, received by a sensor wirelessly connected to the control unit, and the sensor time, which is the internal time of the sensor, is updated to the received device time; b) after step a), the sensor time is transmitted from the sensor, received by the control unit as the received sensor time, and the difference between the device time and the received sensor time is obtained as the first communication difference; c) after step b), the corrected device time, which is the device time plus half of the first communication difference, is transmitted from the control unit; d) after step c), the corrected device time is received by the sensor, The process involves: e) updating the sensor time to the correction device time; after step d), transmitting the sensor time from the sensor, receiving it as the correction sensor time at the control unit, and obtaining the time obtained by adding half of the first communication difference to the difference between the device time and the correction sensor time as the second communication difference; and f) after step e), if the absolute value of the difference between the second communication difference and the first communication difference is greater than a predetermined threshold, updating the first communication difference to be equal to the second communication difference, returning to step c), and performing steps c) through e), and if the absolute value of the difference between the second communication difference and the first communication difference is less than or equal to the threshold, terminating the sensor time update.

[0011] The aforementioned objectives, as well as other objectives, features, embodiments, and advantages, will be revealed by the detailed description of the present invention below, with reference to the attached drawings.

[0012] This is a plan view of the substrate processing system. This is a side view of the substrate processing apparatus. This is a diagram showing the configuration of the control unit. This is a block diagram showing the functions of the control unit. This is a perspective view of the wafer-type sensor. This is a diagram showing the synchronization flow between the sensor time and the device time. This is a schematic diagram illustrating an example of transmitting and receiving the device time and sensor time. This is a schematic diagram illustrating an example of transmitting and receiving the device time and sensor time.

[0013] Figure 1 is a schematic plan view showing the layout of the substrate processing system 10. The substrate processing system 10 is a system for processing semiconductor substrates 9 (hereinafter simply referred to as "substrate 9"). The substrate processing system 10 uses sensors (described later) controlled by a sensor control method according to one embodiment of the present invention.

[0014] The substrate processing system 10 comprises an indexer block 101 and a processing block 102 coupled to the indexer block 101. The indexer block 101 and the processing block 102 are also called an indexer cell and a processing cell, respectively. The indexer block 101 is also called an Equipment Front End Module (EFEM) unit, etc.

[0015] The indexer block 101 comprises a carrier holding unit 104, an indexer robot 105, and an IR moving mechanism 106. The carrier holding unit 104 holds a plurality of carriers 107 capable of accommodating a plurality of substrates 9. The plurality of carriers 107 (for example, FOUP) are held in the carrier holding unit 104 in an arrangement in a predetermined carrier arrangement direction. The IR moving mechanism 106 moves the indexer robot 105 in the carrier arrangement direction. The indexer robot 105 performs an unloading operation to unload the substrates 9 from the carriers 107, and an loading operation to load the substrates 9 into the carriers 107 held in the carrier holding unit 104. The substrates 9 are transported in a horizontal position by the indexer robot 105.

[0016] The processing block 102 comprises a plurality of processing units 108 (for example, four or more) for processing the substrate 9, and a central robot 109. The plurality of processing units 108 are arranged to surround the central robot 109 in a plan view. Various processing is performed on the substrate 9 in the plurality of processing units 108. The substrate 9 is transported in a horizontal position by the central robot 109. The central robot 109 performs an loading operation to load the substrate 9 into the processing units 108, and an unloading operation to unload the substrate 9 from the processing units 108. Furthermore, the central robot 109 transports the substrate 9 between the plurality of processing units 108. The central robot 109 receives the substrate 9 from the indexer robot 105 and passes the substrate 9 to the indexer robot 105.

[0017] Figure 2 is a side view showing the configuration of the substrate processing apparatus 1. The substrate processing apparatus 1 is one of the multiple processing units 108 shown in Figure 1. In the substrate processing system 10, for example, multiple substrate processing apparatuses 1 having a structure similar to that shown in Figure 2 are provided as multiple processing units 108.

[0018] The substrate processing apparatus 1 is a single-wafer type apparatus that processes substrates 9 one at a time. The substrate processing apparatus 1, for example, supplies a processing liquid to the substrate 9 and performs liquid processing. In this embodiment, the processing liquid is a cleaning liquid, and the liquid processing is a cleaning process for the substrate 9. The substrate processing apparatus 1 comprises a substrate holding section 21, a substrate rotating mechanism 22, a cup section 23, a processing liquid supply section 24, a nozzle moving mechanism 25, and a chamber 11. The substrate holding section 21, the substrate rotating mechanism 22, the cup section 23, the processing liquid supply section 24, and the nozzle moving mechanism 25, etc., are housed in the internal space of the chamber 11. The top of the chamber 11 is provided with an airflow forming section 12 that supplies gas into the internal space to form a downward-flowing airflow (so-called downflow). For example, an FFU (Fan Filter Unit) is used as the airflow forming section 12.

[0019] The substrate holding section 21 holds the substrate 9 in a horizontal position from below. The substrate holding section 21 is a mechanical chuck equipped with, for example, a plurality of chuck pins 211 that directly contact the outer circumference of the substrate 9 to hold the substrate 9. The substrate rotation mechanism 22 rotates the substrate 9 held by the substrate holding section 21 by rotating the substrate holding section 21 around the central axis J1. The substrate rotation mechanism 22 is, for example, a motor. In the substrate processing apparatus 1, the substrate holding section 21 and the substrate rotation mechanism 22 constitute a spin chuck that holds and rotates the substrate 9.

[0020] The cup section 23 comprises an annular cup 231 centered on the central axis J1. The cup 231 is arranged around the entire circumference of the substrate 9 and the substrate holder 21, covering the sides of the substrate 9 and the substrate holder 21. The cup 231 is a liquid receiving container that receives liquids such as processing liquid that are scattered outwards from the rotating substrate 9. A drain port (not shown) is provided at the bottom of the cup 231 to discharge the processing liquid received in the cup 231 to the outside of the chamber 11. The cup 231 moves vertically by a lifting mechanism (not shown).

[0021] The cup portion 23 may include a plurality of cups 231 stacked radially (hereinafter also simply referred to as "radial direction") around the central axis J1. When the cup portion 23 includes a plurality of cups 231, each of the cups 231 can move independently in the vertical direction, and the plurality of cups 231 are switched and used to receive the processing liquid according to the type of processing liquid scattered from the substrate 9.

[0022] The processing liquid supply unit 24 includes a nozzle 241 positioned above the substrate 9. The nozzle 241 discharges the processing liquid toward the upper surface 91 of the substrate 9. In this embodiment, the processing liquid supplied to the substrate 9 from the nozzle 241 is a cleaning liquid used to clean the substrate 9, as described above. In the processing liquid supply unit 24, for example, multiple types of processing liquids may be switched and discharged from the nozzle 241. Alternatively, the processing liquid supply unit 24 may include multiple nozzles 241, each discharging multiple types of processing liquids.

[0023] The nozzle moving mechanism 25 is a swinging mechanism that swings the nozzle 241 substantially horizontally in the space above the substrate 9. The nozzle moving mechanism 25 comprises an arm 251 and an arm rotation mechanism 252. The arm 251 is a rod-shaped member that extends substantially horizontally. The nozzle 241 is fixed to one end of the arm 251, and the other end is connected to the arm rotation mechanism 252, which is located radially outside the cup portion 23. The arm rotation mechanism 252 rotates the arm 251 substantially horizontally around a rotation axis that extends vertically. The arm rotation mechanism 252 is, for example, a motor.

[0024] The nozzle movement mechanism 25 reciprocates the nozzle 241, which discharges the processing liquid onto the rotating substrate 9, between a first position that is vertically opposite to the center of the upper surface 91 of the substrate 9, and a second position that is radially outward from the first position. Preferably, the second position is vertically opposite to the outer peripheral region of the upper surface 91 of the substrate 9. This ensures that the processing liquid is supplied substantially evenly over substantially the entire upper surface 91 of the substrate 9.

[0025] As shown in Figure 1, the substrate processing system 10 further comprises a control unit 8. Figure 3 is a diagram showing the configuration of the control unit 8. The control unit 8 has the configuration of a general computer system, including a CPU 81, a GPU 82, a ROM 83, a RAM 84, a fixed disk 85, a display 86, an input unit 87, a reader 88, a communication unit 89, and a bus 80. The CPU 81 performs various arithmetic processing. The GPU 82 performs various arithmetic processing related to image processing. The ROM 83 stores the basic program. The RAM 84 stores various information. The fixed disk 85 stores information. The display 86 is a display unit that displays various information such as images.

[0026] The input unit 87 includes a keyboard 87a and a mouse 87b that accept input from the operator. The reader 88 reads information from a computer-readable recording medium 881 such as an optical disk, magnetic disk, magneto-optical disk, or memory card. The display 86, keyboard 87a, mouse 87b, and reader 88 are connected to the bus 80 via an interface I / F. The communication unit 89 sends and receives signals to and from external devices of the control unit 8. The bus 80 is a signal circuit that connects the CPU 81, GPU 82, ROM 83, RAM 84, fixed disk 85, display 86, input unit 87, reader 88, and communication unit 89.

[0027] In the control unit 8, the program 882 is read in advance from the recording medium 881 via the reader 88 and stored in the fixed disk 85. The program 882 may also be stored in the fixed disk 85 via a network. The CPU 81 and GPU 82 perform arithmetic processing using the RAM 84 and fixed disk 85 according to the program 882. The CPU 81 and GPU 82 function as the arithmetic unit in the control unit 8. Other configurations besides the CPU 81 and GPU 82 that function as the arithmetic unit may also be employed.

[0028] Figure 4 is a block diagram showing some of the functions realized by the execution of program 882 in the control unit 8. The control unit 8 comprises a storage unit 801, a data receiving unit 802, and a data transmission unit 803. The storage unit 801 is realized by RAM 84 and a fixed disk 85, etc. The data receiving unit 802 and the data transmission unit 803 are realized by a CPU 81, GPU 82, ROM 83, RAM 84, a fixed disk 85, and their peripheral configurations. The storage unit 801 stores various information. The data receiving unit 802 and the data transmission unit 803 are used for data communication with sensors 95 that are brought into the substrate processing device 1 and used for various measurements.

[0029] Figure 5 is a perspective view showing an example of a roughly disc-shaped sensor 95. The sensor 95 is, for example, a wafer-type sensor with substantially the same shape as the substrate 9. The sensor 95 is held by a substrate holding unit 21 in place of the substrate 9 in the substrate processing apparatus 1 shown in Figure 2, and measures the processing state of the substrate 9 in the substrate processing apparatus 1 (hereinafter also referred to as "substrate state"). The substrate state measured by the sensor 95 is, for example, the temperature distribution on the substrate 9 or the vibration of the substrate 9. The substrate state measured by the sensor 95 can be changed in various ways.

[0030] As illustrated in Figure 5, the sensor 95 comprises a sensor unit 96 and a data communication unit 97. The sensor unit 96 measures the substrate state described above. The data communication unit 97 is wirelessly connected to the control unit 8 shown in Figure 4 via Bluetooth or the like, and communicates data with the control unit 8. The data communication unit 97 transmits, for example, the substrate state acquired by the sensor unit 96 and the time when the substrate state was measured (i.e., the measurement time) to the control unit 8. The measurement time is the internal time of the sensor 95 (hereinafter also referred to as "sensor time"), which is indicated by the sensor 95's built-in clock (not shown).

[0031] The control unit 8 is equipped with an internal clock (not shown) that is different from the internal clock of the sensor 95. The internal time of the control unit 8 (hereinafter also referred to as the "device time"), indicated by the internal clock of the control unit 8, is synchronized with the sensor time described above. In the control unit 8, the substrate state and measurement time transmitted from the sensor 95 are received by the data receiving unit 802 and stored in the storage unit 801. The device state, which indicates the state of the substrate processing device 1 at the measurement time, is then compared with the substrate state described above, and for example, the relationship between the device state and the substrate state is obtained.

[0032] Next, the synchronization of the sensor time and the device time, which is performed by controlling the sensor 95 in the substrate processing apparatus 1, will be explained with reference to Figures 6 to 8. Figure 6 is a diagram showing the flow of synchronization between the sensor time and the device time. Figures 7 and 8 are schematic diagrams showing examples of transmission and reception of the device time and sensor time. Synchronization between the sensor time and the device time is performed, for example, before the start of logging by the sensor 95 (i.e., recording of measured values ​​measured by the sensor unit 96) each time logging is performed.

[0033] When the sensor time is synchronized with the device time, first, as shown in Figure 7, the data transmission unit 803 of the control unit 8 transmits the device time t ａ１ The data is transmitted to the sensor 95 and received by the data communication unit 97 of the sensor 95 (step S11). The sensor 95 receives the sensor time t of the built-in clock (not shown). ｓ However, the received device time t ａ１ The device time t from the control unit 8 in step S11 is updated (step S12). ａ１ Between the transmission and reception at sensor 95, the time required for data transmission between the control unit 8 and sensor 95 (hereinafter also referred to as "data communication time") has elapsed, therefore, the sensor time t updated in step S12 ｓ This differs from the device time of the control unit 8 at the time step S12 is performed. Note that the data communication time may vary from communication to communication depending on the state of wireless communication between the control unit 8 and the sensor 95, the state of computational load in the control unit 8, etc.

[0034] In the example shown in Figure 7, the device time t transmitted from the control unit 8 in step S11 ａ１ This is 0.000 seconds, and the sensor time t updated in step S12. ｓ It is also 0.000 seconds. Furthermore, the data communication time in step S11 is 0.450 seconds, and the device time of the control unit 8 at the time step S12 is performed is 0.450 seconds.

[0035] When step S12 is completed, the data communication unit 97 of the sensor 95 transmits the sensor time t ｓis transmitted to the control unit 8 and received as the received sensor time t at the data receiving unit 802 of the control unit 8 (step S13). Step S13 is performed after a predetermined elapsed time t (for example, the clock period in the sensor 95) has elapsed from step S12. Therefore, the sensor time t transmitted from the sensor 95 in step S13 (that is, the received sensor time t received by the control unit 8) is the time obtained by adding the elapsed time t to the device time t received by the sensor 95 in step S12. In the control unit 8, the difference between the device time t at the time when the received sensor time t is received and the received sensor time t is obtained as the first communication difference Δt and stored in the storage unit 801 (step S14). ｓ２ In step S13, it is received as (step S13). Step S13 is performed after a predetermined elapsed time t (for example, the clock period of the sensor 95) has elapsed from step S12. Therefore, the sensor time t transmitted from the sensor 95 in step S13 (that is, the received sensor time t received by the control unit 8) is the time obtained by adding the elapsed time t to the device time t received by the sensor 95 in step S12. ｓｄ After the elapse of a certain time (for example, the clock period in the sensor 95), the sensor time t transmitted from the sensor 95 in step S13 (that is, the received sensor time t received by the control unit 8) is the time obtained by adding the elapsed time t to the device time t received by the sensor 95 in step S12. ｓ That is, the received sensor time t received by the control unit 8 ｓ２ is the time obtained by adding the elapsed time t to the device time t received by the sensor 95 in step S12. ａ１ to the elapsed time t ｓｄ is the time obtained by adding the elapsed time t to the device time t received by the sensor 95 in step S12. In the control unit 8, the difference between the device time t at the time when the received sensor time t is received and the received sensor time t is obtained as the first communication difference Δt and stored in the storage unit 801 (step S14). ｓ２ and the received sensor time t ａ２ is obtained as the first communication difference Δt ｓ２ and stored in the storage unit 801 (step S14). １ and stored in the storage unit 801 (step S14).

[0036] In the example shown in FIG. 7, the elapsed time t ｓｄ is 0.100 seconds, and the sensor time t transmitted from the sensor 95 in step S13 (that is, the received sensor time t ｓ That is, the received sensor time t ｓ２ = t ａ１ + t ｓｄ ) is 0.100 seconds. Also, the device time of the control unit 8 at the time when the transmission from the sensor 95 is performed in step S13 is 0.550 seconds. The data communication time in step S13 is 0.450 seconds. Therefore, the device time t of the control unit 8 at the time when the received sensor time t is received ｓ２ is 1.000 seconds, and the sensor time t in the sensor 95 at this time ａ２ is 0.550 seconds. Also, the first communication difference Δt ｓ is 0.550 seconds. Also, the first communication difference Δt １ (= t ａ２ - t ｓ２ ) is 0.900 seconds.

[0037] When step S14 ends and a predetermined time (for example, 1.000 seconds) has elapsed, from the data transmission unit 803 of the control unit 8, half of the first communication difference Δt is added to the device time t to obtain the corrected device time t ａ３ to the device time t １ half of the first communication difference Δt is added to obtain the corrected device time tａ３＿Ａ (=t ａ３ +Δt １ / 2) is transmitted to sensor 95 (step S15). Sensor 95 receives the correction device time t ａ３＿Ａ The data is received by the data communication unit 97, and the sensor time t of the built-in clock (not shown) is recorded. ｓ However, the time t of the correction device received ａ３＿Ａ It is updated to (step S16).

[0038] In the example shown in Figure 7, the device time t of the control unit 8 at the time when step S15 is performed. ａ３ This is 2.000 seconds, and the correction device time t is transmitted from the control unit 8 in step S15. ａ３＿Ａ This is 2.450 seconds. Also, the sensor time t updated in step S16 ｓ The time is 2.450 seconds. The data communication time in step S15 is 0.450 seconds, and the device time of the control unit 8 at the time step S16 is performed is 2.450 seconds.

[0039] When step S16 is completed, the data communication unit 97 of the sensor 95 transmits the sensor time t ｓ The data is transmitted to the control unit 8, and the data receiving unit 802 of the control unit 8 corrects the sensor time t ｓ４ It is received as (step S17). Step S17 is performed from step S16 for the elapsed time t described above. ｓｄ Since this is performed after the elapsed time, the sensor time t is transmitted from the sensor 95 in step S17. ｓ (That is, the correction sensor time t received by the control unit 8) ｓ４ ) is the correction device time t received by the sensor 95 in step S16. ａ３＿Ａ elapsed time t ｓｄ This is the time when the correction sensor time t is added. The control unit 8 adjusts the correction sensor time t ｓ４ The device time t at the time of reception ａ４ and correction sensor time t ｓ４ The difference between this and the first communication difference Δt １ The time obtained by adding half of the above is the second communication difference Δt. ２ It is requested as such and stored in the memory unit 801 (step S18).

[0040] In the example shown in Figure 7, the elapsed time tｓｄ This is 0.100 seconds, and the sensor time t is transmitted from the sensor 95 in step S17. ｓ (That is, correction sensor time t) ｓ４ = t ａ３＿Ａ +t ｓｄ The corrected sensor time t is 2.550 seconds. Also, the device time of the control unit 8 at the time when the sensor 95 transmits data in step S17 is 2.550 seconds. The data communication time in step S17 is 0.450 seconds. Therefore, the corrected sensor time t ｓ４ The device time t of the control unit 8 at the time of receiving the signal. ａ４ This is 3.000 seconds, and the sensor time t at sensor 95 at this time is 3.000 seconds. ｓ It is 3.000 seconds. Also, the second communication difference Δt ２ (=t ａ４ -t ｓ４ +Δt １ (2) is 0.900 seconds.

[0041] When step S18 is completed, the control unit 8 calculates the second communication difference Δt ２ and the first communication difference Δt １ The absolute value of the difference (hereinafter also called "communication difference Δt") is calculated and compared with a predetermined threshold (step S19). In the example shown in Figure 7, the communication difference Δt (= |Δt) ２ -Δt １ The threshold value is 0.000 seconds. The above threshold value is set in advance and stored in the storage unit 801. The threshold value is set in the range of, for example, 0.050 seconds to 0.100 seconds, and in this embodiment it is 0.100 seconds. When the communication difference Δt is less than or equal to the threshold value, the device time of the control unit 8 and the sensor time t of the sensor 95 are used. ｓ If the discrepancy is determined to be within an acceptable range, the sensor time update (i.e., time synchronization of the sensor time) is terminated. Note that the above threshold is not limited to the range described above and may be changed in various ways.

[0042] In the example shown in Figure 8, steps S11 to S18 described above are performed in substantially the same manner as in the example shown in Figure 7, resulting in the first communication difference Δt １ and the second communication difference Δt ２ This is required. In the example shown in Figure 8, the device time t ａ１ , device time tａ２ and the reception sensor time t ｓ２ and the first communication difference Δt １ are 0.000 seconds, 1.000 seconds, 0.100 seconds, and 0.900 seconds, respectively, similar to the example shown in FIG. 7. On the other hand, the device time t ａ３ , the device time t ａ４ , the corrected sensor time t ｓ４ and the second communication difference Δt ２ are 2.000 seconds, 3.200 seconds, 2.550 seconds, and 1.100 seconds, respectively. Therefore, the communication difference Δt obtained in step S19 is 0.200 seconds, which is larger than the above threshold value (0.100 seconds).

[0043] In this case, the first communication difference Δt １ is updated to be equal to the second communication difference Δt ２ (step S20). In the example shown in FIG. 8, the value of the first communication difference Δt １ stored in the storage unit 801 is rewritten to the value of the second communication difference Δt ２ , which is 1.100 seconds.

[0044] Then, it returns to step S15, and from the data transmission unit 803 of the control unit 8, the corrected device time t ａ５ obtained by adding half of the first communication difference Δt １ to the device time t ａ５＿Ａ (= t ａ５ +Δt １ / 2) is transmitted to the sensor 95 (step S15). In the sensor 95, the corrected device time t ａ５＿Ａ is received by the data communication unit 97, and the sensor time t ｓ of the built-in clock (not shown) is updated to the received corrected device time t ａ５＿Ａ (step S16).

[0045] In the example shown in FIG. 8, the device time t ａ５ of the control unit 8 at the time when step S15 is performed is 3.200 seconds. As described above, since the first communication difference Δt １ is 1.100 seconds, the corrected device time t ａ５＿Ａ transmitted from the control unit 8 in step S15 is 3.750 seconds. Also, the sensor time t updated in step S16ｓ It is also 3.750 seconds. The data communication time in step S15 is 0.600 seconds, and the device time of the control unit 8 when step S16 is performed is 3.800 seconds.

[0046] When step S16 ends, the sensor time t from the data communication unit 97 of the sensor 95 ｓ is transmitted to the control unit 8 and received as the corrected sensor time t by the data reception unit 802 of the control unit 8 (step S17). Since step S17 is performed after the elapse of the above-mentioned elapsed time t ｓ６ from step S16, the sensor time t ｓｄ transmitted from the sensor 95 in step S17 (that is, the corrected sensor time t ｓ received by the control unit 8) is the time obtained by adding the elapsed time t ｓ６ to the corrected device time t received by the sensor 95 in step S16. In the control unit 8, the time obtained by adding half of the first communication difference Δt ａ５＿Ａ to the difference between the device time t ｓｄ at the time of receiving the corrected sensor time t ｓ６ and the corrected sensor time t ａ６ is obtained as the second communication difference Δt ｓ６ and stored in the storage unit 801 (step S18). １ ２

[0047] In the example shown in FIG. 8, the elapsed time t ｓｄ is 0.100 seconds, and the sensor time t ｓ transmitted from the sensor 95 in step S17 (that is, the corrected sensor time t ｓ６ = t ａ５＿Ａ + t ｓｄ ) is 3.850 seconds. Also, the device time of the control unit 8 when the transmission from the sensor 95 is performed in step S17 is 3.900 seconds. The data communication time in step S17 is 0.600 seconds. Therefore, the device time t ｓ６ of the control unit 8 at the time of receiving the corrected sensor time t ａ６ is 4.500 seconds, and the sensor time t ｓ in the sensor 95 at this time is 4.450 seconds. Also, the second communication difference Δt ２ (= tａ６ -t ｓ６ +Δt １ (2) is 1.200 seconds.

[0048] When step S18 is completed, the control unit 8 calculates the communication difference Δt (i.e., the second communication difference Δt) ２ and the first communication difference Δt １ The absolute value of the difference between the two is calculated and compared with the threshold mentioned above (step S19). In the example shown in Figure 8, the communication difference Δt (= |Δt) ２ -Δt １ |) is 0.100 seconds, which is below the threshold, therefore the device time of the control unit 8 and the sensor time of the sensor 95 t ｓ The discrepancy is determined to be within an acceptable range, and the sensor time update (i.e., time synchronization of the sensor time) is terminated.

[0049] As described above, the sensor control method for controlling the sensor 95 (wafer-type sensor in the above example) in the substrate processing apparatus 1 is the apparatus time t, which is the internal time of the control unit 8 of the substrate processing apparatus 1. ａ１ The control unit 8 transmits this signal, which is received by the sensor 95, which is wirelessly connected to the control unit 8, and the sensor time t is the internal time of the sensor 95. ｓ The device received the signal at time t ａ１ The process of updating to (steps S11 to S12), and after steps S11 to S12, the sensor time t from sensor 95 ｓ The signal is transmitted, and the control unit 8 receives the sensor time t ｓ２ Received as, device time t ａ２ and received sensor time t ｓ２ The difference between this and the first communication difference Δt １ The process includes obtaining as (steps S13 to S14).

[0050] The sensor control method is performed after steps S13 to S14, at device time t ａ３ The first communication difference Δt １ Correction device time t by adding 1 / 2 of ａ３＿Ａ Step S15: The control unit 8 transmits the following: After step S15, the correction device time t ａ３＿Ａ The sensor 95 receives the signal, and the sensor time t ｓ Correction device time t ａ３＿ＡThe process of updating to (step S16), and after step S16, the sensor time t from sensor 95 ｓ The signal is transmitted, and the control unit 8 corrects the sensor time t ｓ４ Received as, device time t ａ４ and correction sensor time t ｓ４ The difference between this and the first communication difference Δt １ The time obtained by adding half of the second communication difference Δt ２ The process of obtaining as (steps S17 to S18) is further provided.

[0051] The sensor control method, after steps S17 to S18, includes the second communication difference Δt ２ and the first communication difference Δt １ If the absolute value of the difference is greater than a predetermined threshold (step S19), the first communication difference Δt １ The second communication difference Δt ２ Update to be equal to (step S20), return to step S15 and perform steps S15 to S19, and the second communication difference Δt ２ and the first communication difference Δt １ If the absolute value of the difference is less than or equal to the above threshold (step S19), then sensor time t ｓ It further includes a process to terminate the update.

[0052] This allows for optimal time synchronization between the substrate processing apparatus 1 and the sensor 95, which is wirelessly connected. As a result, the correlation between the apparatus status of the substrate processing apparatus 1 and the measured values ​​obtained by the sensor 95 can be obtained with high accuracy.

[0053] As described above, the sensor 95 is preferably a wafer-type sensor with a roughly disc shape. This allows for accurate acquisition of the correlation between the state of the substrate processing apparatus 1 and the processing state of the substrate 9 in the substrate processing apparatus 1 (i.e., the state of the substrate). As a result, for example, it is possible to improve throughput and reduce the amount of chemicals used in the substrate processing apparatus 1.

[0054] As described above, preferably, each time logging is performed by the sensor 95, steps S11 to S20 are performed before the start of logging, and the sensor time t ｓThis is updated. This allows for accurate acquisition of the correlation between the device status of the substrate processing device 1 and the measured values ​​obtained by the sensor 95 in each logging operation.

[0055] In the sensor control method described above, for example, steps S11 to S20 described above may be performed multiple times before logging by the sensor 95 begins, and the sensor time may be synchronized using the arithmetic mean of the multiple synchronization results. This further suppresses the effects of variations in data communication time caused by the state of wireless communication between the control unit 8 and the sensor 95, the state of computational load in the control unit 8, etc.

[0056] As described above, steps S11 to S20 are performed by executing a computer-readable program 882 on a computer. This allows for suitable time synchronization of the sensor 95, which is wirelessly connected to the substrate processing apparatus 1, as described above. As a result, the correlation between the device status of the substrate processing apparatus 1 and the measured values ​​obtained by the sensor 95 can be obtained with high accuracy.

[0057] Various modifications are possible to the sensor control method and program 882 described above.

[0058] In the above example, the sensor time update (steps S11 to S20) is performed before the start of each logging operation by the sensor 95, but is not limited to this. For example, the sensor time update may be performed each time a predetermined number of logs are performed, or it may be performed every predetermined amount of time.

[0059] In the above example, the device time was described as the time indicated by the internal clock of the control unit 8, but it is not limited to this. For example, the device time may be the elapsed time starting from some reference time within the control unit 8.

[0060] The sensor 95 does not necessarily need to perform measurements while the substrate is held by the substrate holding unit 21 inside the substrate processing apparatus 1. For example, measurements may be performed when the substrate is loaded into the processing unit 108 by the center robot 109, or when it is unloaded from the processing unit 108 by the center robot 109. Alternatively, the sensor 95 may perform measurements while being transported within the substrate processing system 10 by the center robot 109 or the indexer robot 105. In this case, the substrate processing system 10 is considered to be the substrate processing apparatus that the sensor 95 is measuring.

[0061] The sensor 95 is not necessarily limited to a wafer-type sensor, and may be various sensors wirelessly connected to the control unit 8. For example, the sensor 95 may be a sensor fixed to the substrate processing device 1.

[0062] The substrate processing apparatus 1 and substrate processing system 10 may be used for processing glass substrates used in flat panel displays such as liquid crystal displays or organic electroluminescence (EL) displays, or glass substrates used in other displays, in addition to semiconductor substrates. Furthermore, the substrate processing apparatus 1 and substrate processing system 10 may be used for processing substrates for optical discs, magnetic discs, magneto-optical discs, photomasks, ceramic substrates, and solar cell substrates.

[0063] The configurations in the above embodiments and each modified example may be combined as appropriate, as long as they do not contradict each other.

[0064] Although the invention has been described in detail, the above description is illustrative and not limiting. Therefore, it can be said that numerous modifications and embodiments are possible as long as they do not deviate from the scope of the present invention.

[0065] 1 Substrate processing device 8 Control unit 10 Substrate processing system 95 Sensor 882 Program S11-S20 Steps

Claims

1. A sensor control method for controlling a sensor in a substrate processing apparatus, comprising: a) transmitting the device time, which is the internal time of the control unit of the substrate processing apparatus, from the control unit, receiving it at a sensor wirelessly connected to the control unit, and updating the sensor time, which is the internal time of the sensor, to the received device time; b) after step a), transmitting the sensor time from the sensor, receiving it as the received sensor time at the control unit, and obtaining the difference between the device time and the received sensor time as the first communication difference; c) after step b), transmitting a corrected device time from the control unit, which is the device time plus half of the first communication difference; d) after step c), receiving the corrected device time at the sensor, and updating the sensor time to the corrected device time; e) after step d), transmitting the sensor time from the sensor, receiving it as the corrected sensor time at the control unit, and obtaining the time obtained by adding half of the first communication difference to the difference between the device time and the corrected sensor time as the second communication difference; f) If, after step e), the absolute value of the difference between the second communication difference and the first communication difference is greater than a predetermined threshold, update the first communication difference to be equal to the second communication difference, return to step c), and perform steps c) through e), and if the absolute value of the difference between the second communication difference and the first communication difference is less than or equal to the threshold, terminate the update of the sensor time.

2. A sensor control method according to claim 1, wherein the sensor is a substantially disc-shaped wafer-type sensor.

3. A sensor control method according to claim 1 or 2, wherein each time logging is performed by the sensor, steps a) through f) are performed before the start of the logging to update the sensor time.

4. A computer-readable program for controlling a sensor in a substrate processing apparatus, wherein when the program is executed on a computer, a) the device time, which is the internal time of the control unit of the substrate processing apparatus, is transmitted from the control unit, received by a sensor wirelessly connected to the control unit, and the sensor time, which is the internal time of the sensor, is updated to the received device time; b) after step a), the sensor time is transmitted from the sensor, received by the control unit as the received sensor time, and the difference between the device time and the received sensor time is obtained as the first communication difference; c) after step b), the corrected device time, which is the device time plus half of the first communication difference, is transmitted from the control unit; d) after step c), the corrected device time is received by the sensor, and the sensor time is updated to the corrected device time. e) After step d), the sensor transmits the sensor time, which is received by the control unit as a corrected sensor time, and the time obtained as a second communication difference is the difference between the device time and the corrected sensor time plus half of the first communication difference; f) After step e), if the absolute value of the difference between the second communication difference and the first communication difference is greater than a predetermined threshold, the first communication difference is updated to be equal to the second communication difference, the process returns to step c) and proceeds from step c) to step e), and if the absolute value of the difference between the second communication difference and the first communication difference is less than or equal to the threshold, the update of the sensor time is terminated; a computer-readable program.

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