Sensor module and measurement system

Abstract

A sensor module according to the present invention comprises: a piezoelectric oscillator that has an electrode; an oscillation circuit that drives and oscillates the piezoelectric oscillator; and a storage circuit that stores, as initial oscillation frequency information, an oscillation frequency that is measured by oscillating the piezoelectric oscillator when the piezoelectric oscillator is shipped, wherein when the piezoelectric oscillator is driven by the oscillation circuit, the piezoelectric oscillator oscillates at a frequency corresponding to the thickness of a deposit that has been deposited on a surface of the electrode. The storage circuit may store information pertaining to a first identification number for identifying the piezoelectric oscillator and / or a second identification number for identifying the sensor module.

Description

Sensor module and measurement system

[0001] The present invention relates to a sensor module and a measurement system.

[0002] Conventionally, a quartz crystal microbalance (QCM) sensor using a quartz crystal oscillator is known. The QCM sensor can detect the presence or absence of a substance based on the difference between the resonant frequency of a reference quartz crystal oscillator and the resonant frequency of a detection quartz crystal oscillator to which the substance adheres (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2018-080947

[0004] Such a sensor can be installed in a material deposition device, such as a semiconductor manufacturing device, and used to detect the thickness of deposited material based on changes in the resonant frequency of the oscillator as the material accumulates. However, as the amount of material deposited on the oscillator increases, the oscillator's oscillation limit is exceeded, and the semiconductor manufacturing device may no longer be able to function as a sensor while the material is being deposited.

[0005] The present invention has been made in consideration of these points, and aims to make it possible to identify the lifespan of an oscillator mounted in a sensor that uses an oscillator to detect the amount of deposits.

[0006] In a first aspect of the present invention, a sensor module is provided, comprising: a piezoelectric vibrator having electrodes; an oscillation circuit that drives the piezoelectric vibrator to oscillate; and a memory circuit that stores, as initial oscillation frequency information, an oscillation frequency measured by oscillating the piezoelectric vibrator when the piezoelectric vibrator is shipped; and when driven by the oscillation circuit, the piezoelectric vibrator oscillates at a frequency corresponding to the thickness of deposits accumulated on the surface of the electrodes.

[0007] The storage circuit may further store information on at least one of a first identification number for identifying the piezoelectric vibrator and a second identification number for identifying the sensor module.

[0008] The storage circuit may be configured to be able to update information by overwriting previously stored information in a storage area.

[0009] In a second aspect of the present invention, there is provided a measurement system comprising the sensor module of the first aspect and a control device connected to the sensor module, wherein the control device has a frequency measurement unit that measures the oscillation frequency of the piezoelectric vibrator based on the oscillation frequency signal output by the oscillation circuit, a memory control unit that is capable of accessing the memory circuit of the sensor module and reading information stored in the memory circuit, a thickness determination unit that determines the thickness of the deposits deposited on the surface of the electrode of the piezoelectric vibrator based on the oscillation frequency measured by the frequency measurement unit, and a life determination unit that determines the life of the piezoelectric vibrator based on the initial oscillation frequency information read from the memory circuit by the memory control unit and the oscillation frequency measured by the frequency measurement unit.

[0010] The sensor module may further include a temperature sensor that measures the surface temperature of the substrate on which the piezoelectric vibrator is mounted, and an acquisition unit that acquires the measurement results of the temperature sensor, and the life determination unit may determine the life of the piezoelectric vibrator by comparing the initial oscillation frequency information with a corrected frequency obtained by correcting the oscillation frequency measured by the frequency measurement unit based on the surface temperature of the substrate.

[0011] The control device further includes an input unit for allowing a user to input measurement conditions for measuring the thickness of the deposit, and the memory control unit is further capable of accessing the memory circuit of the sensor module and writing specified information to the memory circuit, and when the frequency measurement unit measures the oscillation frequency of the piezoelectric vibrator after the input unit receives a specified operation indicating that the measurement system has been installed, the memory control unit may update the initial oscillation frequency information stored in the memory circuit to information about the measured oscillation frequency of the piezoelectric vibrator.

[0012] According to the present invention, it is possible to determine the life of an oscillator mounted in a sensor that uses an oscillator to detect the amount of deposits.

[0013] 1 shows an example of a case where a measurement system S according to this embodiment is applied to a semiconductor manufacturing device 1. FIG. 2 shows an example of the configuration of a sensor module 10 according to this embodiment. FIG. 3 shows an example of the configuration of a control device 100 according to this embodiment. FIG. 4 shows an operation flow of the control device 100 according to this embodiment.

[0014] 1 shows an example of a case where the measurement system S according to this embodiment is applied to a semiconductor manufacturing apparatus 1. The semiconductor manufacturing apparatus 1 is an apparatus for stacking semiconductor materials on a semiconductor wafer W. The semiconductor manufacturing apparatus 1 includes a chamber 2, a stage 3, and a film forming apparatus 4.

[0015] The chamber 2 is a container that seals a predetermined space. The chamber 2 is, for example, a vacuum chamber that can maintain a low air pressure in the sealed space. The stage 3 is provided inside the chamber 2 and mounts a semiconductor wafer W. The stage 3 may be configured to be movable within the chamber 2 while the semiconductor wafer W is mounted thereon.

[0016] The film forming apparatus 4 is an apparatus for depositing a material such as a metal, an insulator, or a semiconductor on the surface of the semiconductor wafer W. The film forming apparatus 4 is, for example, an apparatus for depositing a material by a liquid phase method or a vapor phase method, an apparatus for applying a material, or the like. Since various types of film forming apparatus 4 are known, a detailed description thereof will be omitted here. By using such a film forming apparatus 4, a semiconductor material is deposited on the surface of the semiconductor wafer W to form a thin film.

[0017] In such a semiconductor manufacturing apparatus 1, the thickness of the semiconductor material deposited on the semiconductor wafer W can be estimated by using, for example, the film formation conditions and film formation time of the film formation apparatus 4. However, there are cases where it is desired to measure the thickness of the semiconductor material actually deposited on the semiconductor wafer W. In particular, there are cases where it is desired to measure the thickness of the semiconductor material in real time while the semiconductor material is being formed. Therefore, the measurement system S according to this embodiment measures the thickness of the semiconductor material deposited on the surface of such a semiconductor wafer W.

[0018] The measurement system S includes a sensor module 10, a connection cable 30, and a control device 100. The sensor module 10 is installed inside the chamber 2. Like the semiconductor wafer W, the sensor module 10 is provided in an area where the film forming device 4 can deposit material, and measures the thickness of the material deposited on the sensor module 10 itself. The sensor module 10 and the control device 100 will be described later.

[0019] The connection cable 30 connects the sensor module 10 in the chamber 2 to the control device 100 outside the chamber 2. The connection cable 30 connects the sensor module 10 to the control device 100 via, for example, a connector 5. In this case, the connector 5 is provided in the chamber 2 and is configured to be able to send and receive electrical signals while maintaining the airtightness of the chamber 2. Next, the sensor module 10 of the measurement system S will be described.

[0020] <Configuration Example of Sensor Module 10> Fig. 2 shows a configuration example of the sensor module 10 according to this embodiment. Fig. 2 schematically shows a cross section of the sensor module 10. The sensor module 10 has a substrate 11, a piezoelectric vibrator 12, a heater circuit 14, an oscillation circuit 15, a memory circuit 16, a base member 17, a coupling socket 18, a temperature sensor 19, and a cover 20.

[0021] The substrate 11 is a substrate for fixing the piezoelectric vibrator 12. The substrate 11 is, for example, a ceramic substrate such as a low temperature co-fired ceramics (LTCC) substrate.

[0022] The piezoelectric vibrator 12 has electrodes 13, and when driven by the oscillation circuit 15, oscillates at a frequency corresponding to the thickness of deposits accumulated on the surface of the electrodes 13. The piezoelectric vibrator 12 is, for example, a quartz crystal vibrator, a ceramic vibrator, a langasite vibrator, or the like. In this embodiment, an example will be described in which the piezoelectric vibrator 12 is a two-electrode type quartz crystal vibrator formed on a quartz crystal substrate composed of a single quartz crystal piece.

[0023] One electrode 13a of the piezoelectric vibrator 12 is provided on the opposite side of the substrate 11 and is exposed to the outside. The other electrode 13b of the piezoelectric vibrator 12, which is different from the electrode 13a, is provided in a position that is not exposed to the outside. As a result, when the film forming device 4 of the semiconductor manufacturing apparatus 1 starts depositing the semiconductor material, the semiconductor material is deposited on the surface of the electrode 13a of the piezoelectric vibrator 12.

[0024] The heater circuit 14 adjusts the temperature of the piezoelectric vibrator 12 via the substrate 11. The heater circuit 14 has, for example, a heater that heats the piezoelectric vibrator 12. The heater is, for example, a Peltier element, a resistor, a heating wire, or the like. The heater may be provided on the surface of the substrate 11 opposite to the piezoelectric vibrator 12, or alternatively, may be provided in an inner layer of the substrate 11.

[0025] The heater circuit 14 has a function of adjusting the amount of heat based on the temperature of the substrate 11 measured by the temperature sensor 19. The heater circuit 14 has a circuit that adjusts the power supplied to the heater so as to maintain the temperature of the substrate 11 at a predetermined temperature or within a predetermined temperature range. The heater circuit 14 functions as a heating control unit that controls the amount of heat from the heater based on, for example, the difference between the temperature measured by the temperature sensor 19 and a target temperature.

[0026] The oscillator circuit 15 has a circuit for driving the piezoelectric vibrator 12 to oscillate in response to a control signal from the control device 100. If the sensor module 10 has multiple vibrators, the oscillator circuit 15 has a circuit for oscillating each of the multiple vibrators. The oscillator circuit 15 outputs a signal oscillated by the piezoelectric vibrator 12 as an oscillation frequency signal. The oscillation frequency signal output by the oscillator circuit 15 is input to the control device 100 via the connector 5 and the connection cable 30. The oscillator circuit 15 is formed on a predetermined circuit board.

[0027] The storage circuit 16 stores, as initial oscillation frequency information, the oscillation frequency measured by oscillating the piezoelectric vibrator 12 before shipping the piezoelectric vibrator 12. The storage circuit 16 is a nonvolatile memory. The storage circuit 16 is preferably a memory that can be read and rewritten by an electrical signal.

[0028] The memory circuit 16 is configured to be able to update information by overwriting previously stored information in a memory area. As a result, when the memory area of ​​the memory circuit 16 becomes full of information, the old memory area can be overwritten with the latest information. The memory circuit 16 may be formed on the circuit board on which the oscillator circuit 15 is formed, or alternatively, on another circuit board.

[0029] The base member 17 is a member for fixing the oscillator circuit 15. The coupling socket 18 is a member for electrically connecting the oscillator circuit 15 and the piezoelectric vibrator 12. For example, a pin (not shown) that is electrically connected to the piezoelectric vibrator 12 and protrudes from the substrate 11 is inserted into the coupling socket 18. Since the piezoelectric vibrator 12 is connected to the oscillator circuit 15 via the pin and the coupling socket 18, even if heating by the heater circuit 14 causes a wide range of temperature changes and expansion and contraction in various parts, the coupling socket 18 can absorb the stress caused by the expansion and contraction.

[0030] The temperature sensor 19 measures the surface temperature of the substrate 11 on which the piezoelectric vibrator 12 is provided. The temperature sensor 19 is, for example, a resistance temperature detector using platinum or the like, a thermocouple, a thermistor, or the like. The temperature sensor 19 is preferably attached in contact with the substrate 11. Alternatively, the temperature sensor 19 may be attached in contact with the piezoelectric vibrator 12.

[0031] The cover 20 covers the sensor module 10 except for the electrode 13 a, and has a through hole that exposes the electrode 13 a. When the sensor module 10 is installed inside the chamber 2 so that the electrode 13 a faces the film deposition device 4 of the semiconductor manufacturing apparatus 1, the same material as that deposited on the semiconductor wafer W by the film deposition device 4 is deposited on the electrode 13 a to the same thickness as that deposited on the semiconductor wafer W.

[0032] When a substance is deposited on the electrode 13a of the piezoelectric vibrator 12, the resonant frequency of the piezoelectric vibrator 12 changes depending on the thickness of the deposited substance. Therefore, the control device 100 of the measurement system S determines the thickness of the material deposited on the electrode 13a by measuring such a change in the resonant frequency of the piezoelectric vibrator 12. Such a control device 100 will now be described.

[0033] 3 shows an example of the configuration of the control device 100 according to this embodiment. The control device 100 includes an input unit 110, an interface 120, a power supply unit 130, a frequency measurement unit 140, a storage unit 150, a display unit 160, and a control unit 170.

[0034] The input unit 110 receives operations, instructions, and the like from the user of the control device 100. The input unit 110 is a part that allows the user to input measurement conditions for measuring the thickness of deposits accumulated on the sensor module 10. The input unit 110 has one or more input devices such as a keyboard, a mouse, a touch panel, and a voice input device.

[0035] The interface 120 is connected to the connection cable 30 and is connected to the sensor module 10. The interface 120 is a part for exchanging electrical signals with the sensor module 10. The interface 120 exchanges electrical signals between the heater circuit 14, the oscillation circuit 15, the memory circuit 16, and the temperature sensor 19 and the control device 100, for example.

[0036] The power supply unit 130 supplies power to the sensor module 10. The power supply unit 130 functions as a power source for the circuits and heaters provided in the sensor module 10. The power supply unit 130 may change the power it supplies based on the control operation of the control unit 170.

[0037] The frequency measurement unit 140 receives the oscillation frequency signal output from the oscillation circuit 15 via the interface 120. Then, the frequency measurement unit 140 measures the oscillation frequency of the piezoelectric vibrator 12 based on the oscillation frequency signal. The frequency measurement unit 140 has, for example, a frequency counter or the like, and measures the oscillation frequency of the oscillation frequency signal.

[0038] The frequency measurement unit 140 continuously measures the oscillation frequency of the oscillation frequency signal at least during a deposition period from the start to the end of the deposition operation of the semiconductor material by the film formation device 4 of the semiconductor manufacturing apparatus 1. The frequency measurement unit 140 measures the oscillation frequency of the oscillation frequency signal at predetermined time intervals during the deposition period, for example. The frequency measurement unit 140 supplies the measurement result to the control unit 170. It is preferable that the frequency measurement unit 140 supplies the measurement result to the control unit 170 every time it measures the oscillation frequency.

[0039] The storage unit 150 is a storage medium including a read-only memory (ROM) and a random access memory (RAM). The storage unit 150 may also include a large-capacity storage device such as a hard disk drive (HDD) and / or a solid state drive (SSD). For example, when a computer or the like functions as at least a part of the control device 100, the storage unit 150 may store information such as an operating system (OS) that causes the computer to function, and programs. The storage unit 150 may also store various information including a database that is referenced when a program is executed.

[0040] The storage unit 150 may also store intermediate data, calculation results, thresholds, reference values, parameters, and the like that are generated (or used) by the control device 100 during operation. For example, the storage unit 150 may store information that the control device 100 acquires from the sensor module 10, or may store information to be written to the storage circuit 16 of the sensor module 10. The storage unit 150 may also supply the stored data to a request source in response to a request from each unit within the control device 100.

[0041] The display unit 160 displays information related to the measurement of the thickness of the deposit. The display unit 160 may display, for example, the measurement conditions, the measurement results, the connection status with the sensor module 10, information about the sensor module 10, etc. The display unit 160 may also function as a display for displaying the OS, the execution status of applications, etc. The display unit 160 may have a touch panel function and operate as at least a part of the input unit 110.

[0042] The control unit 170 controls each unit of the control device 100 and the sensor module 10. The control unit 170, for example, reads out information stored in the storage unit 150. The control unit 170 may also cause the storage unit 150 to record information. The control unit 170, for example, transmits a control signal to the oscillation circuit 15 for driving the oscillation circuit 15, causing the oscillation circuit 15 to drive the piezoelectric vibrator 12. The operation of the control unit 170 will be described in more detail below.

[0043] The control unit 170 is, for example, a CPU (Central Processing Unit). The control unit 170 has an acquisition unit 171, a memory control unit 172, a thickness determination unit 173, a lifespan determination unit 174, and a display control unit 175. In other words, the CPU executes a program stored in the storage unit 150 to function as the control unit 170 having the acquisition unit 171, the memory control unit 172, the thickness determination unit 173, the lifespan determination unit 174, and the display control unit 175.

[0044] The acquisition unit 171 acquires the measurement results of the oscillation frequency measured by the frequency measurement unit 140. The acquisition unit 171 also acquires the measurement results of the temperature of the substrate 11 by the temperature sensor 19. The acquisition unit 171 supplies the acquired measurement results of the oscillation frequency and the temperature to the thickness determination unit 173 and the life determination unit 174.

[0045] The memory control unit 172 is configured to be able to access the memory circuit 16 of the sensor module 10 and read information stored in the memory circuit 16. The memory control unit 172, for example, reads and acquires initial oscillation frequency information stored in the memory circuit 16. The memory control unit 172 supplies the acquired initial oscillation frequency information to the life specification unit 174. The memory control unit 172 may be configured to be able to access the memory circuit 16 of the sensor module 10 and write predetermined information to the memory circuit 16.

[0046] The thickness determination unit 173 determines the thickness of the deposit deposited on the surface of the electrode 13 a of the piezoelectric vibrator 12 based on the oscillation frequency measured by the frequency measurement unit 140. The piezoelectric vibrator 12 oscillates at a resonance frequency corresponding to the thickness of the deposit deposited on the surface of the electrode 13 a. Therefore, when the measurement result of the oscillation frequency at the start of the semiconductor material deposition operation by the film formation device 4 of the semiconductor manufacturing apparatus 1 is denoted as f1 and the measurement result of the oscillation frequency after a predetermined time t has elapsed since the start of the deposition operation is denoted as f2, the thickness determination unit 173 can determine the thickness of the deposit after the predetermined time t has elapsed based on the difference in oscillation frequencies Δf = f2 - f1.

[0047] The resonant frequency of the piezoelectric vibrator 12 also changes depending on the temperature. Therefore, it is desirable that the thickness determination unit 173 temperature-compensates the measurement result of the oscillation frequency measured by the frequency measurement unit 140 using the temperature measurement result of the temperature sensor 19. The temperature characteristics of the resonant frequency of the piezoelectric vibrator 12 may be measured and determined in advance, or alternatively, if data is publicly available as specifications of the piezoelectric vibrator 12, the publicly available data may be acquired. It is desirable that the temperature characteristics of the resonant frequency of the piezoelectric vibrator 12 be stored in the storage unit 150.

[0048] The thickness determination unit 173 determines the thickness dd of the deposit based on, for example, the oscillation frequency difference Δf' = f2' - f1' calculated from corrected frequencies f1', f2' obtained by temperature-correcting the oscillation frequency measurement results f1, f2. The relational expression between the oscillation frequency difference and the deposit thickness may be determined by pre-measurement or, alternatively, may be determined from a theoretical formula or the like. The determined relational expression is preferably stored in the storage unit 150. If the heater circuit 14 of the sensor module 10 maintains the temperature of the piezoelectric vibrator 12 at a constant temperature, the temperature correction of the oscillation frequency measurement results f1, f2 may be omitted.

[0049] It is desirable that the thickness specifying unit 173 specifies the thickness of the deposit each time the frequency measuring unit 140 measures the oscillation frequency, thereby enabling the measurement system S to measure the thickness dd of the deposit deposited on the semiconductor wafer W almost in real time.

[0050] The lifespan determination unit 174 determines the lifespan of the piezoelectric vibrator 12 based on the initial oscillation frequency information read by the memory control unit 172 from the memory circuit 16 of the sensor module 10 and the oscillation frequency measured by the frequency measurement unit 140. The piezoelectric vibrator 12 will no longer be able to oscillate when the thickness of deposits accumulated on the surface of the electrode 13a reaches a predetermined thickness. The lifespan determination unit 174 determines the range that can be measured before the piezoelectric vibrator 12 will no longer be able to oscillate as the lifespan.

[0051] The thickness dx of the deposit at which the piezoelectric vibrator 12 becomes inoperable may be measured and specified in advance, or alternatively, if data is publicly available as specifications of the piezoelectric vibrator 12, the publicly available data may be acquired. The thickness dx of the deposit at which the piezoelectric vibrator 12 reaches the end of its life is preferably stored in the memory unit 150. Alternatively, the thickness dx of the deposit at which the piezoelectric vibrator 12 reaches the end of its life may be stored in the memory circuit 16 of the sensor module 10.

[0052] The life specifying unit 174 specifies the life of the piezoelectric vibrator 12 by comparing the initial oscillation frequency information with a corrected frequency obtained by correcting the oscillation frequency measured by the frequency measurement unit 140 based on the surface temperature of the substrate 11. For example, when the initial oscillation frequency information is f0, the life specifying unit 174 specifies the thickness dn of the deposit accumulated from the initial state of the electrode 13a based on the difference Δf0' = f2' - f0 between the initial oscillation frequency information and the oscillation frequency. The formula used by the life specifying unit 174 to calculate the thickness of the deposit from the difference in oscillation frequency is the same as the formula used by the thickness specifying unit 173 to calculate the thickness of the deposit.

[0053] There may be a case where the heater circuit 14 of the sensor module 10 maintains the temperature of the piezoelectric vibrator 12 at the temperature at which the initial oscillation frequency information of the piezoelectric vibrator 12 was measured. In this case, the life determination unit 174 may omit temperature correction of the oscillation frequency measurement result f2.

[0054] When the piezoelectric vibrator 12 in its initial state after shipment is mounted on the sensor module 10 and the thickness of the deposit is measured for the first time, the thickness dn of the deposit accumulated from the initial state of the electrode 13a will be equal to the thickness dd of the deposit identified by the thickness identification unit 173. Furthermore, when one or more measurements have been taken prior to the current measurement of the thickness of the deposit, the thickness obtained by adding the thickness dd of the deposit accumulated in the current measurement to the thickness of the deposit accumulated up to the immediately preceding measurement will be equal to the thickness dn of the deposit accumulated from the initial state of the electrode 13a.

[0055] The lifespan specifying unit 174 calculates the difference Δd=dx−dn between the thickness dx of the deposit at which the piezoelectric vibrator 12 reaches the end of its lifespan and the specified thickness dn of the deposit. The difference Δd is the thickness of the deposit that can be measured by the piezoelectric vibrator 12. The lifespan specifying unit 174 specifies, for example, the measurable thickness Δd of the deposit as the lifespan. Alternatively, or in addition, the lifespan specifying unit 174 may calculate a difference Δfx in the oscillation frequency corresponding to the measurable thickness Δd of the deposit, and specify the difference Δfx as the lifespan.

[0056] The life specifying unit 174 may also calculate an estimated life corresponding to the measurable thickness Δd of the deposit. For example, the life specifying unit 174 divides the thickness of the deposit specified based on the measurement results of two oscillation frequencies measured by the frequency measurement unit 140 at two different times by the time interval between the two different times, and sets the value to the estimated deposition rate vv. Then, the life specifying unit 174 sets the value to the estimated life vt by dividing the measurable thickness Δd of the deposit by the estimated deposition rate vv.

[0057] For example, when the thickness dd of the deposit is measured after a predetermined time t has elapsed, the life specifying unit 174 calculates the estimated life time vt as Δd / vv = Δd t / dd, assuming that the estimated deposition rate vv is dd / t. The life specifying unit 174 may specify the estimated life time vt calculated in this manner as the life. As a result, the life specifying unit 174 can specify the time until the piezoelectric vibrator 12 reaches its measurement limit when deposition proceeds at the same deposition rate as the life.

[0058] It is desirable that the life specification unit 174 specifies the life of the piezoelectric vibrator 12 each time the frequency measurement unit 140 measures the oscillation frequency. This allows the measurement system S to measure the life of the piezoelectric vibrator 12 of the sensor module 10 almost in real time.

[0059] The display control unit 175 displays the thickness of the deposit identified by the thickness identification unit 173 and the lifetime of the piezoelectric vibrator 12 identified by the lifetime identification unit 174 on the display unit 160. This allows the user of the measurement system S to understand the thickness of the deposited semiconductor material and the lifetime of the piezoelectric vibrator 12 of the sensor module 10 while depositing the semiconductor material on the semiconductor wafer W using the semiconductor manufacturing apparatus 1. This allows the user to understand the appropriate time to replace the sensor module 10.

[0060] For example, after the film forming device 4 of the semiconductor manufacturing apparatus 1 has completed depositing a semiconductor material, the life of the piezoelectric vibrator 12 identified by the life identifying unit 174 indicates the measurement limit at which the measurement system S can measure the thickness of the next deposit. Therefore, the user can easily determine whether to continue the next operation of the semiconductor manufacturing apparatus 1 or to replace the sensor module 10 and then resume operation.

[0061] The control device 100 may measure the life of the piezoelectric vibrator 12 immediately after powering on and becoming ready to measure the thickness of the deposit. Alternatively, the control device 100 may measure the life of the piezoelectric vibrator 12 in response to the user inputting measurement conditions into the input unit 110. This allows the user to easily determine whether or not to replace the sensor module 10 before starting operation of the semiconductor manufacturing apparatus 1. The operation of such a control device 100 will now be described.

[0062] <Operation Flow of the Control Device 100> Figure 4 shows the operation flow of the control device 100 according to this embodiment. First, the input unit 110 accepts measurement conditions input by the user (S51). The measurement conditions may include information on the thickness of the semiconductor material to be deposited on the semiconductor wafer W. Next, the memory control unit 172 accesses the memory circuit 16 of the sensor module 10 and reads and acquires the initial oscillation frequency information stored in the memory circuit 16 (S52). Next, the control unit 170 causes the oscillation circuit 15 to drive the piezoelectric vibrator 12 (S53).

[0063] Next, the control unit 170 measures the thickness of the deposit accumulated on the piezoelectric vibrator 12 (S54). In this case, the frequency measurement unit 140 measures the oscillation frequency of the piezoelectric vibrator 12, and the acquisition unit 171 acquires the oscillation frequency measurement result and the temperature measurement result of the temperature sensor 19. Then, the thickness identification unit 173 measures the thickness of the deposit accumulated on the piezoelectric vibrator 12 based on the oscillation frequency measurement result and the temperature measurement result. The display control unit 175 displays the identified thickness of the deposit on the display unit 160.

[0064] Next, the control unit 170 identifies the life of the piezoelectric vibrator 12 (S55). In this case, the life identification unit 174 identifies the life of the piezoelectric vibrator 12 based on the oscillation frequency measurement results, the temperature measurement results, and the initial oscillation frequency information. The display control unit 175 displays the identified life of the piezoelectric vibrator 12 on the display unit 160. This allows the user to understand the information about the piezoelectric vibrator 12 before the semiconductor material is deposited on the semiconductor wafer W.

[0065] Next, the input unit 110 receives a command from the user to start measurement (S56). Here, the user inputs a command to start measurement into the input unit 110, for example, when the film formation device 4 of the semiconductor manufacturing equipment 1 starts depositing semiconductor material. Alternatively, if the measurement conditions input by the user include a measurement start time, the control unit 170 may start measurement when the measurement start time arrives. Furthermore, the control device 100 may be connected via a network or the like to a control device that controls the operation of the semiconductor manufacturing equipment 1. In this case, the control device 100 may receive a start signal to start measurement from the control device of the semiconductor manufacturing equipment 1.

[0066] The control device 100 measures the thickness of the deposit (S57) in the same manner as in S54, and determines the life of the piezoelectric vibrator 12 in the same manner as in S55 (S58). The control device 100 repeats the operations of S57 and S58 until the input unit 110 receives a signal indicating the end of the measurement (S59: Yes) (S59: No). Here, the user inputs a command to end the measurement into the input unit 110, for example, when the film forming device 4 of the semiconductor manufacturing apparatus 1 finishes depositing the semiconductor material. Alternatively, if the measurement conditions input by the user include a measurement end time, the control unit 170 may end the measurement when the measurement end time arrives. The control device 100 may also receive an end signal to end the measurement from the control device of the semiconductor manufacturing apparatus 1.

[0067] According to the measurement system S of this embodiment described above, by storing the initial oscillation frequency information of the piezoelectric vibrator 12 in the memory circuit 16 of the sensor module 10, the memory control unit 172 of the control device 100 can read out the initial oscillation frequency information and identify the life of the piezoelectric vibrator 12. As a result, when the semiconductor manufacturing apparatus 1 deposits a semiconductor material on a semiconductor wafer W, it is possible to measure the life of the piezoelectric vibrator 12 while measuring the thickness of the deposited semiconductor material almost in real time.

[0068] Therefore, the user can replace the sensor module 10 at an appropriate time, and can prevent the piezoelectric vibrator 12 from becoming inoperable while the semiconductor manufacturing apparatus 1 is depositing semiconductor material. Furthermore, when the sensor module 10 is replaced, the control device 100 can determine the lifespan of the replaced piezoelectric vibrator 12 by reading out the initial oscillation frequency information stored in the memory circuit 16 of the replaced sensor module 10.

[0069] <Other Configurations> In the measurement system S according to the present embodiment described above, an example has been described in which the user replaces the sensor module 10 before the piezoelectric vibrator 12 stops working, but the present invention is not limited to this. The user may also replace the piezoelectric vibrator 12 of the sensor module 10. When the user replaces the piezoelectric vibrator 12 of the sensor module 10, the measurement system S may update the initial oscillation frequency information of the piezoelectric vibrator 12 before replacement in the memory circuit 16 to the initial oscillation frequency information of the piezoelectric vibrator 12 after replacement.

[0070] In this case, for example, the frequency measurement unit 140 measures the oscillation frequency of the replaced piezoelectric vibrator 12, and the memory control unit 172 writes the measurement result of the frequency measurement unit 140 as initial oscillation frequency information into the memory circuit 16. This allows the measurement system S to identify the lifespan of the replaced piezoelectric vibrator 12.

[0071] The measurement system S according to the present embodiment has been described above as an example in which the initial oscillation frequency information of the piezoelectric vibrator 12 is stored in the memory circuit 16 of the sensor module 10, but is not limited to this. In addition, the memory circuit 16 may store information on at least one of a first identification number for identifying the piezoelectric vibrator 12 and a second identification number for identifying the sensor module 10.

[0072] When the first identification number and / or the second identification number are stored in the memory circuit 16, the memory control unit 172 may read out the first identification number and / or the second identification number when reading out the initial oscillation frequency information. In this case, the display control unit 175 displays the read out first identification number and / or the second identification number on the display unit 160. This allows the user to know information identifying the sensor module 10 and / or the piezoelectric vibrator 12 used for measurement, which can be useful for maintenance, management, etc. of the sensor module 10 and / or the piezoelectric vibrator 12.

[0073] In the measurement system S according to the present embodiment, the sensor module 10 has been described above as an example in which the storage circuit 16 stores, as initial oscillation frequency information, the oscillation frequency measured by oscillating the piezoelectric vibrator 12 before shipping the piezoelectric vibrator 12. However, the present invention is not limited to this. The storage circuit 16 only needs to record information for identifying the lifespan of the piezoelectric vibrator 12.

[0074] For example, the memory circuit 16 may store, as initial oscillation frequency information, the oscillation frequency measured by oscillating the piezoelectric vibrator 12 when the measurement system S is installed. For example, when the frequency measurement unit 140 measures the oscillation frequency of the piezoelectric vibrator 12 after the input unit 110 receives a predetermined operation indicating that the measurement system S has been installed, the memory control unit 172 updates the initial oscillation frequency information stored in the memory circuit 16 to information about the measured oscillation frequency of the piezoelectric vibrator 12.

[0075] As a result, for example, when the measurement system S is applied to the semiconductor manufacturing equipment 1 to construct a semiconductor manufacturing system, the memory circuit 16 can reliably store the initial value of the piezoelectric vibrator 12 actually mounted on the sensor module 10. The memory circuit 16 may also store information on the environmental temperature when the initial oscillation frequency information is measured. Note that although an example in which the measurement system S according to this embodiment is applied to the semiconductor manufacturing equipment 1 has been described, this is merely one example. The measurement system S can be applied to any device that deposits deposits, not just the semiconductor manufacturing equipment 1.

[0076] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments.

[0077] REFERENCE SIGNS LIST 1 semiconductor manufacturing equipment 2 chamber 3 stage 4 film forming equipment 5 connector 10 sensor module 11 substrate 12 piezoelectric vibrator 13 electrode 14 heater circuit 15 oscillation circuit 16 memory circuit 17 base member 18 coupling socket 19 temperature sensor 20 cover 30 connection cable 100 control device 110 input unit 120 interface 130 power supply unit 140 frequency measurement unit 150 memory unit 160 display unit 170 control unit 171 acquisition unit 172 memory control unit 173 thickness determination unit 174 life determination unit 175 display control unit

Claims

1. A sensor module comprising: a piezoelectric vibrator having electrodes; an oscillation circuit that drives the piezoelectric vibrator to oscillate; and a memory circuit that stores an oscillation frequency measured by oscillating the piezoelectric vibrator when the piezoelectric vibrator is shipped as initial oscillation frequency information, wherein when the piezoelectric vibrator is driven by the oscillation circuit, it oscillates at a frequency corresponding to the thickness of deposits accumulated on the surface of the electrodes.

2. The sensor module according to claim 1, wherein the memory circuit further stores information on at least one of a first identification number for identifying the piezoelectric vibrator and a second identification number for identifying the sensor module.

3. The sensor module according to claim 2, wherein the memory circuit is configured to be capable of updating information by overwriting previously stored information in the memory area.

4. A measurement system comprising: the sensor module according to any one of claims 1 to 3; and a control device connected to the sensor module, wherein the control device has: a frequency measurement unit that measures the oscillation frequency of the piezoelectric vibrator based on an oscillation frequency signal output by the oscillation circuit; a memory control unit that is capable of accessing the memory circuit of the sensor module and reading information stored in the memory circuit; a thickness determination unit that determines a thickness of the deposit deposited on the surface of the electrode of the piezoelectric vibrator based on the oscillation frequency measured by the frequency measurement unit; and a life determination unit that determines a life of the piezoelectric vibrator based on the initial oscillation frequency information read from the memory circuit by the memory control unit and the oscillation frequency measured by the frequency measurement unit.

5. The measurement system of claim 4, wherein the sensor module further comprises a temperature sensor that measures a surface temperature of a substrate on which the piezoelectric vibrator is provided, and an acquisition unit that acquires the measurement results of the temperature sensor, and the life determination unit determines the life of the piezoelectric vibrator by comparing a corrected frequency obtained by correcting the oscillation frequency measured by the frequency measurement unit based on the surface temperature of the substrate with the initial oscillation frequency information.

6. The measurement system of claim 5, wherein the control device further comprises an input unit for allowing a user to input measurement conditions for measuring the thickness of the deposit, the memory control unit is further capable of accessing the memory circuit of the sensor module and writing specified information into the memory circuit, and when the frequency measuring unit measures the oscillation frequency of the piezoelectric vibrator after the input unit receives a specified operation indicating that the measurement system has been installed, the memory control unit updates the initial oscillation frequency information stored in the memory circuit to information on the measured oscillation frequency of the piezoelectric vibrator.