JP2008139067A - Temperature measurement substrate and temperature measurement system - Google Patents

Abstract

A temperature measurement system capable of measuring a substrate temperature with extremely high accuracy is provided.
A plurality of recesses are carved into a substrate surface of a temperature measurement substrate TW, and a temperature measuring element 15 is bonded and fixed inside each of the recesses. The transmission / reception unit 20 and each temperature detecting element 15 are wired by a coaxial cable 50, and an electric signal is given from the transmission / reception unit 20 to resonate a crystal resonator built in the temperature detection element 15, and the frequency is counted. The temperature of the temperature measurement substrate TW is calculated from the frequency change rate. The recess 11 is engraved to a depth that is almost half the thickness of the temperature measurement substrate TW, and the temperature measuring element 15 can measure the temperature in the vicinity of the central portion in the thickness direction of the temperature measurement substrate TW. In addition, since the concave portion is formed so that the weight of the temperature measurement substrate TW with the temperature measuring element 15 and the weight of the substrate to be processed normally become equal, the heat capacities of the two become almost equal, and more accurate. It is possible to perform a high substrate temperature measurement.
[Selection] Figure 4

Description

  The present invention relates to a temperature measurement substrate placed on a heat treatment plate for heat treatment of a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, and the like, and a heat treatment using the temperature measurement substrate The present invention relates to a temperature measurement system that measures the temperature of a substrate placed on a plate.

  As is well known, products such as semiconductors and liquid crystal displays are subjected to a series of processes such as cleaning, resist coating, exposure, development, etching, interlayer insulating film formation, heat treatment, and dicing on the semiconductor substrate and the like. It is manufactured by. Among these, the heat treatment is, for example, a process performed after pattern exposure, after application of an SOG (Spin on glass) material that is a material of an interlayer insulating film, or after application of a photoresist. This is an essential processing step. Therefore, it is necessary to measure the temperature of the substrate as accurately as possible in a heat treatment unit that performs heat treatment of the substrate. In Patent Document 1, a temperature sensor is installed on the substrate, and the temperature sensor and transmission for transmitting detection data are performed. An apparatus for connecting the apparatus with a cable is disclosed. Patent Document 2 discloses a technique in which a temperature sensor and a transmitter or a memory are provided on a temperature measurement substrate.

  Patent Document 3 proposes a technique for measuring temperature by using a damped vibration when a crystal resonator is mounted on a temperature measurement substrate and the crystal resonator is resonated at a natural frequency. ing. Since the quartz resonator has high heat resistance and high thermal sensitivity, temperature measurement can be performed with high accuracy even on a high-temperature substrate.

JP 2002-124457 A JP-A-11-307606 JP 2004-140167 A

  However, with the recent progress of higher precision design rules, the demand for temperature accuracy for heat treatment of substrates has become increasingly severe. In particular, the heat treatment after the photoresist coating described above directly affects the film thickness and film quality of the resist film to be formed, and the post-exposure heat treatment when using a chemically amplified resist directly affects the line width of the pattern. There is a strong demand for accurately heating a substrate to a temperature required in the process. Therefore, it is an issue to more accurately measure the temperature of the substrate during the heat treatment.

  The present invention has been made in view of the above problems, and an object thereof is to provide a temperature measurement system capable of measuring the temperature of a substrate with extremely high accuracy, and a temperature measurement substrate used in the system. To do.

  In order to solve the above problems, the invention of claim 1 is a temperature measurement substrate placed on a heat treatment plate for performing heat treatment of a substrate to be processed, the substrate having a plurality of recesses formed on a surface thereof, A plurality of temperature measuring elements fitted in the recesses and having a crystal resonator.

  According to a second aspect of the present invention, in the temperature measurement substrate according to the first aspect of the present invention, the weight in a state where the plurality of temperature detecting elements are fitted is equal to that of the substrate to be processed.

  The invention of claim 3 is the temperature measurement system for measuring the temperature of the substrate placed on the heat treatment plate, and is for temperature measurement according to the invention of claim 1 or 2 placed on the heat treatment plate. Transmitting and receiving means for transmitting an electrical signal to each of the plurality of temperature sensing elements mounted on the substrate and receiving an electrical signal from each of the plurality of temperature sensing elements, and electricity from each temperature sensing element received by the transmission and reception means Temperature calculating means for calculating the temperature of the substrate for temperature measurement based on the frequency of the signal.

  According to a fourth aspect of the present invention, in the temperature measurement system according to the third aspect of the present invention, the plurality of temperature sensing elements and the transmitting / receiving means are connected by a coaxial cable.

  The invention according to claim 5 is the temperature measurement system according to claim 4, further comprising: a plate cover that covers the upper part of the heat treatment plate; and an elevating unit that raises and lowers the plate cover. A board-side connector connected to each of the plurality of temperature sensing elements is provided on the upper surface of the board, a cover-side connector connected to the transmitting / receiving means is provided on the lower surface of the plate cover, and the plate cover is lowered by the elevating means. The board-side connector and the cover-side connector are sometimes fitted to connect the plurality of temperature measuring elements and the transmitting / receiving means.

  According to a sixth aspect of the present invention, in the temperature measurement system according to the fourth or fifth aspect of the present invention, the transmission / reception means transmits an electric signal having the same frequency to the plurality of temperature measuring elements.

  The invention according to claim 7 is the temperature measurement system according to the invention of claim 3, further comprising a plate cover that covers an upper portion of the heat treatment plate, wherein the plurality of temperature measuring elements are coils connected to a crystal resonator, or The antenna further comprises an antenna, wherein the transmission / reception means transmits a transmission wave to the plurality of temperature sensing elements via a transmission / reception antenna provided on the plate cover, and after stopping transmission of the transmission wave, an electromagnetic wave from the temperature sensing element Is received via the transmission / reception antenna.

  In this specification, the term “substrate” simply includes both a temperature measurement substrate and a normal processing target substrate such as a semiconductor substrate or a glass substrate for a liquid crystal display device.

  According to the first and second aspects of the present invention, since the plurality of temperature measuring elements having the crystal resonator are fitted in the concave portions formed on the surface of the substrate, the crystal resonator capable of measuring the temperature with high accuracy is provided. Thus, the temperature inside the thickness measuring substrate can be measured, and the temperature of the substrate can be measured with extremely high accuracy.

  In particular, according to the second aspect of the present invention, since the weight in a state where the plurality of temperature sensing elements are fitted is equal to the substrate to be processed, the heat capacities of the temperature measurement substrate and the normal substrate to be processed are substantially equal. As a result, the temperature rise / fall behavior of the temperature measurement substrate becomes substantially the same as that of a normal substrate to be processed, and it becomes possible to perform more accurate substrate temperature measurement.

  Further, according to the inventions of claims 3 to 7, since the temperature measurement substrate according to the invention of claim 1 or 2 is placed on the heat treatment plate and the temperature measurement is performed, the substrate with extremely high accuracy. Temperature can be measured.

  In particular, according to the invention of claim 4, since the plurality of temperature measuring elements and the transmission / reception means are connected by wire with a coaxial cable, it is possible to perform reliable substrate temperature measurement.

  In particular, according to the invention of claim 5, since the plurality of temperature sensing elements and the transmission / reception means are connected by the board side connector and the cover side connector being fitted, a reliable connection between the temperature sensing element and the transmission / reception means is achieved. Can be established.

  In particular, according to the invention of claim 6, since the transmission / reception means transmits electric signals having the same frequency to the plurality of temperature measuring elements, the number of times of temperature measurement per unit time is reduced by shortening the sampling time required for one temperature measurement. Can be more.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<1. Temperature measurement board>
First, the temperature measurement substrate according to the present invention will be described. FIG. 1 is a plan view of the temperature measurement substrate TW in a state where no temperature sensing element is fitted. The temperature measurement substrate TW is formed of the same material as the semiconductor substrate to be processed in the same size, and in this embodiment is a disk-shaped substrate of φ300 mm of silicon. A plurality (17 in this embodiment) of recesses 11 are formed on the surface of the temperature measurement substrate TW. As shown in FIG. 1, one concave portion 11 is formed at the center of the temperature measurement substrate TW, and eight concave portions 11 are formed at intervals of 45 ° on a circumference having a radius of 140 mm, and a circle having a radius of 280 mm. Eight concave portions 11 are formed on the circumference at intervals of 45 °. Each of the plurality of recesses 11 has a substantially rectangular parallelepiped shape.

  As shown in FIG. 2, a temperature detecting element 15 is fitted in each of the plurality of recesses 11. The temperature measuring element 15 is configured by incorporating a crystal resonator 18 in a package. Crystals have different natural frequencies depending on the angle cut from the crystal and have various temperature characteristics, and so-called Ys cuts of them have a large rate of change in transmission / reception frequency with respect to temperature. When an electric signal having a frequency corresponding to the natural frequency is transmitted to the crystal unit 18 and the frequency of the electric signal received from the crystal unit 18 is measured after the transmission is stopped, the temperature detecting element 15 is based on the change rate of the transmission / reception frequency. Temperature can be calculated. If a quartz resonator is used, temperature measurement can be performed with very high accuracy compared to a resistance temperature detector or the like.

  One temperature detecting element 15 is fitted in each of the plurality of recesses 11. Specifically, the temperature measuring element 15 is bonded and fixed in the recess 11 using an adhesive. Adhesive has heat resistance and generates almost no gas even when heated to high temperatures (for example, a silicone-based conductive adhesive in which silver powder is kneaded into a heat-curing type silicone resin or has high thermal stability. Use polyimide varnish based on aromatic polyimide). Further, it is preferable to use a material having elasticity in consideration of the difference in coefficient of thermal expansion from the silicon substrate as the package of the temperature measuring element 15. Note that a transmission / reception electrode (not shown) is provided in the package of the temperature measuring element 15.

  In the present embodiment, the temperature sensing element 15 is not simply fixed to the substrate surface, but the recess 11 is carved and the temperature sensing element 15 is fitted therein. The thickness of the temperature measurement substrate TW is 0.72 mm, while the depth of the recess 11 is 0.35 mm. That is, the recess 11 is engraved to a depth that is almost half the thickness of the temperature measurement substrate TW. Therefore, the temperature measuring element 15 can measure the temperature in the vicinity of the center portion in the thickness direction of the temperature measuring substrate TW, and can measure the temperature of the substrate with higher accuracy.

  Further, as a result of engraving the recess 11 and bonding and fixing the temperature measuring element 15 thereto, the weight of the temperature measuring substrate TW is equal to the weight of the semiconductor substrate to be processed normally. That is, the concave portion 11 is formed by cutting silicon of the same mass as the temperature measuring element 15. For this reason, the heat capacities of the temperature measurement substrate TW and the semiconductor substrate to be processed normally are almost equal, and as a result, the temperature measurement substrate TW has a temperature increase and decrease behavior that is substantially the same as that of the semiconductor substrate to be processed normally. It becomes the same thing, and it becomes possible to perform more accurate substrate temperature measurement.

<2. First Example of Temperature Measurement System>
Next, a temperature measurement system using the temperature measurement substrate TW will be described. FIG. 3 is an overall configuration diagram of a temperature measurement system according to the present invention, and FIG. 4 is an essential configuration diagram thereof. Here, the temperature of the substrate placed on the heat treatment plate 31 of the heat treatment unit 30 is measured using the temperature measurement substrate TW.

  The heat treatment unit 30 is configured by accommodating a heat treatment plate 31 and a plate cover 40 inside a chamber (not shown). The heat treatment plate 31 is an aluminum disk and incorporates a heater made of a resistance heating element. For example, three proximity balls (not shown) made of ceramics are embedded in the upper surface of the heat treatment plate 31. The substrate to be processed is placed on the heat treatment plate 31 through a proximity ball with a predetermined gap (for example, 0.1 mm) and heated.

  An air cylinder 32 is provided below the heat treatment plate 31, and a plurality of (for example, three) support pins 33 are moved up and down all at once by the air cylinder 32. The front end portion of the support pin 33 is inserted into a through hole formed in the heat treatment plate 31 in the vertical direction. When the air cylinder 32 raises the support pin 33, the front end portion projects upward from the heat treatment plate 31. When the air cylinder 32 lowers the support pin 33, the tip portion returns to a position lower than the upper surface of the heat treatment plate 31. As a result, the support pins 33 can be raised to lift the substrate from the heat treatment plate 31, and the support pins 33 can be lowered to pass the substrate onto the heat treatment plate 31.

  The plate cover 40 is provided so as to cover the upper part of the heat treatment plate 31. As indicated by an arrow AR 3 in the figure, the plate cover 40 can be moved up and down by a lifting mechanism 41 between a standby position spaced upward from the heat treatment plate 31 and a processing position close to the heat treatment plate 31. When heat treatment is performed in the heat treatment unit 30, the plate cover 40 is lowered to the processing position. Further, when the substrate is carried in and out of the heat treatment unit 30 by a transfer robot (not shown), the plate cover 40 is raised to the standby position. As the elevating mechanism 41, various linear drive mechanisms such as a screw feeding mechanism using a ball screw, a belt feeding mechanism using a belt, an air cylinder, and the like can be adopted.

  When the substrate temperature is measured by the heat treatment unit 30, the above-described temperature measurement substrate TW is placed on the heat treatment plate 31. Specifically, the temperature measurement substrate TW is placed on the raised support pins 33 by the transfer robot or manually, and the support pins 33 are lowered to place the temperature measurement substrate TW on the heat treatment plate 31. Is done.

  In the temperature measurement system of the first example, each of the 17 temperature sensing elements 15 of the temperature measurement substrate TW and the transmission / reception unit 20 are individually connected (wired) by the coaxial cable 50. As the coaxial cable 50, a cable covered with a sheath (outermost protective coating) of a fluororesin (for example, Teflon (registered trademark)) excellent in heat resistance is used.

  The transmission / reception unit 20 includes a switch 21, a transmitter 22, a receiver 23 and a frequency counter 24. The switch 21 switches the connection destination of each temperature sensing element 15 between the transmitter 22 and the receiver 23. The transmitter 22 transmits an electrical signal having a predetermined frequency to the quartz vibrators 18 of the 17 temperature measuring elements 15. The receiver 23 receives electrical signals from the crystal resonators 18 of the 17 temperature measuring elements 15. A frequency counter 24 is connected to the receiver 23, and the frequency counter 24 counts the frequency of the electrical signal received by the receiver 23.

  Furthermore, a temperature calculation unit 29 is connected to the frequency counter 24. The temperature calculation unit 29 calculates the temperature of the temperature measurement substrate TW based on the frequency of the electrical signal counted by the frequency counter 24. The transmission / reception unit 20 and the temperature calculation unit 29 may be incorporated in a part of the heat treatment unit 30 or may be provided separately from the heat treatment unit 30. When the transmission / reception unit 20 and the temperature calculation unit 29 are incorporated in a part of the heat treatment unit 30, the transmission / reception unit 20 and the temperature calculation unit 29 may be controlled by the controller of the heat treatment unit 30. Further, when the transmission / reception unit 20 and the temperature calculation unit 29 are provided outside the heat treatment unit 30, the transmission / reception unit 20 and the temperature calculation unit 29 may be controlled by a separate controller.

  When the temperature measurement substrate TW is placed on the heat treatment plate 31 and temperature measurement is performed, first, the switch 21 is switched to the transmitter 22 side, and each of the plurality of temperature measuring elements 15 and the transmitter 22 are connected to the coaxial cable. 50 and connected individually. Next, an electrical signal having a frequency corresponding to the natural frequency of the quartz vibrator 18 of the 17 temperature sensing elements 15 provided on the temperature measurement substrate TW is transmitted from the transmitter 22. The frequency of the transmitted electrical signal is also transmitted from the transmitter 22 to the temperature calculation unit 29. In the temperature measurement system of the first example configured by wired connection, the natural frequencies of the 17 crystal resonators 18 are set to substantially the same frequency band. Therefore, the transmitter 22 can simultaneously transmit electric signals having the same frequency to the plurality of temperature measuring elements 15.

  The electrical signals transmitted from the transmitter 22 are transmitted individually and simultaneously to each of the 17 temperature measuring elements 15 via the coaxial cable 50. As a result, the crystal resonators 18 included in the 17 temperature measuring elements 15 resonate at substantially the same timing. Subsequently, the transmission of the transmitter 22 is stopped, the transmission of the electrical signal is stopped, and the switch 21 is switched to the receiver 23 side.

  When the transmission of the electrical signal is stopped, the 17 resonated crystal oscillators 18 have a frequency corresponding to the temperature of the temperature measurement substrate TW (more precisely, the temperature at the position where the crystal oscillator 18 is attached). Oscillates with damping. An electric signal resulting from this damped vibration is transmitted from the crystal resonator 18. The electric signals transmitted from each of the 17 crystal resonators 18 are individually received by the receiver 23 at substantially the same timing. The frequency counter 24 individually counts the frequencies of the electrical signals from the 17 crystal resonators 18 received by the receiver 23 and transmits the count value to the temperature calculation unit 29. The temperature calculation unit 29 calculates the change rate of the transmission / reception frequency based on the frequency of the electrical signal counted by the frequency counter 24 and the frequency of the transmitted electrical signal transmitted from the transmitter 22, and calculates 17 from the change rate. The temperature of the temperature measurement substrate TW at the position where the crystal resonators 18 are attached is calculated individually.

  If it carries out as mentioned above, the temperature of the board | substrate mounted on the heat processing plate 31 can be measured using the board | substrate TW for temperature measurement. As described above, in the temperature measurement substrate TW, the plurality of recesses 11 are engraved on the substrate surface, and the temperature measuring element 15 is fitted inside each of them, so that the crystal vibration capable of high-precision temperature measurement. The temperature near the central portion of the temperature measuring substrate TW in the thickness direction is measured by the element 18, and the temperature of the substrate can be measured with extremely high accuracy.

  In addition, as a result of engraving the recess 11 and fitting the temperature measuring element 15 there, the heat capacity of the temperature measurement substrate TW and the semiconductor substrate to be processed normally become substantially equal, and is placed on the heat treatment plate 31. Since then, the temperature change behavior of the temperature measurement substrate TW is substantially the same as that of a semiconductor substrate to be processed normally. Therefore, the temperature of the substrate placed on the heat treatment plate 31 and to be processed can be measured with higher accuracy.

  In the temperature measurement system of the first example, each of the 17 temperature measuring elements 15 of the temperature measurement substrate TW and the transmission / reception unit 20 are individually connected via a coaxial cable 50 in a wired manner. For this reason, not only transmission / reception of electric signals can be ensured, but also electric signals of the same frequency are simultaneously transmitted to the crystal resonators 18 of the seventeen temperature sensing elements 15, and the electric signals from them are transmitted. Reception can be performed at substantially the same timing, and as a result, the sampling time required for one temperature measurement can be shortened to increase the number of temperature measurements per unit time (for example, about once per second). Therefore, the accuracy of the temperature measurement of the substrate can be further increased.

<3. Second Example of Temperature Measurement System>
Next, a second example of the temperature measurement system using the temperature measurement substrate TW will be described. FIG. 5 is an overall configuration diagram of the temperature measurement system of the second example, and FIG. 6 is an essential configuration diagram thereof. Also in the second example, the temperature of the substrate placed on the heat treatment plate 31 of the heat treatment unit 30 is measured using the temperature measurement substrate TW. The second example is different from the first example in the connection mode between the transmission / reception unit 20 and the temperature measuring element 15, and the remaining points are the same as those in the first example, and thus common to the first example. The same reference numerals as those in FIGS. 3 and 4 are given to the members in FIGS. 5 and 6.

  In the temperature measurement system of the second example, the board-side connector 12 is fixed on the upper surface (front surface) of the temperature measurement board TW. The board-side connector 12 has 17 sets of terminals (one set of terminals is composed of two contacts) arranged in parallel upward. Each of the 17 sets of terminals is connected to 17 temperature sensing elements 15 on a one-to-one basis. A coaxial cable covered with the same fluororesin as described above may be used for connection between the terminals of the board-side connector 12 and the temperature detecting element 15.

  On the other hand, a cover-side connector 42 is fixed on the lower surface side of the plate cover 40. The cover-side connector 42 is also provided with 17 sets of terminals facing downward. Each of the 17 sets of terminals of the cover-side connector 42 is individually connected to the transmission / reception unit 20.

  When the elevating mechanism 41 descends the plate cover 40, the board-side connector 12 and the cover-side connector 42 are fitted, and a connection is established between the 17 sets of terminals of both connectors. As a result, each of the 17 temperature measuring elements 15 of the temperature measurement board TW and the transmitting / receiving unit 20 are individually connected (wired) via the board side connector 12 and the cover side connector 42. In addition, when the raising / lowering mechanism 41 raises the plate cover 40, the board | substrate side connector 12 and the cover side connector 42 will space apart, and the connection of the temperature sensing element 15 and the transmission / reception part 20 will be interrupted | blocked.

  When temperature measurement is performed in the temperature measurement system of the second example, first, after the temperature measurement substrate TW is placed on the heat treatment plate 31, the elevating mechanism 41 lowers the plate cover 40 to lower the temperature measurement substrate TW. Each of the 17 temperature measuring elements 15 is connected to the transmission / reception unit 20. The subsequent temperature measurement method is the same as that of the first example described above, and an electric signal is individually transmitted to the crystal resonators 18 of the 17 temperature measuring elements 15, and after the transmission is stopped, the signals from the 17 crystal resonators 18 are transmitted. The temperature calculation unit 29 receives the electrical signal, calculates the change rate of the transmission / reception frequency, and individually calculates the temperature of the temperature measurement substrate TW at the position where the 17 crystal resonators 18 are attached from the change rate.

  Even if it does in this way, the effect similar to the said 1st example can be acquired, and the temperature of a board | substrate can be measured with a very high precision. In particular, according to the second example, since the connection between the temperature measuring element 15 and the transmission / reception unit 20 is established by lowering the plate cover 40, wiring is simplified.

<4. Third Example of Temperature Measurement System>
Next, a third example of the temperature measurement system using the temperature measurement substrate TW will be described. In the above first and second examples, the transmission / reception unit 20 and the temperature detecting element 15 are connected by wire, but in the third example, wireless connection is used.

  FIG. 7 is a perspective view of the temperature measuring element 15 used in the third example. The temperature measuring element 15 is the same as the first and second examples in that the crystal resonator 18 is built in the package. However, in the third example, a coil 19 is connected to the crystal resonator 18. ing. The 17 crystal resonators 18 attached to the temperature measurement substrate TW have different natural frequencies depending on the cut-out angle. A mode in which the 17 concave portions 11 are formed in the temperature measurement substrate TW is the same as in the first and second examples. In the third example, the temperature measuring element 15 to which the coil 19 is attached is fitted into the concave portion 11 of the temperature measurement substrate TW, as in the first and second examples. Note that the axis of the coil 19 is configured to face the vertical direction in a state where the temperature measurement substrate TW is placed on the heat treatment plate 31. Further, instead of the coil 19, an antenna having various configurations may be connected to the crystal unit 18.

  FIG. 8 is an overall configuration diagram of the temperature measurement system of the third example, and FIG. 9 is an essential configuration diagram thereof. Also in the third example, the temperature of the substrate placed on the heat treatment plate 31 of the heat treatment unit 30 is measured using the temperature measurement substrate TW. 8 and 9, members common to the first example are denoted by the same reference numerals as those in FIGS. 3 and 4.

  In the temperature measurement system of the third example, the temperature measuring element 15 having the coil 19 connected to the crystal resonator 18 is fitted to the temperature measurement substrate TW, and the temperature measurement substrate TW is placed on the heat treatment plate 31. Is done. Each temperature detecting element 15 is provided with one coil 19, and the temperature measuring substrate TW is provided with 17 coils 19. Correspondingly, 17 sensor coils 45 are attached to the lower surface side of the plate cover 40. The sensor coil 45 is provided above each of the 17 temperature sensing elements 15 and functions as a transmission / reception antenna for the coil 19 of each temperature sensing element 15. Each of the 17 sensor coils 45 is individually connected to the transmission / reception unit 20.

  When the temperature measurement substrate TW is placed on the heat treatment plate 31 and the elevating mechanism 41 lowers the plate cover 40, the 17 temperature measuring elements 15 and the 17 sensor coils 45 face each other in a one-to-one relationship. Each of the elements 15 and the transmission / reception unit 20 are individually connected (wireless connection) via the sensor coil 45. Even when the plate cover 40 is lowered, the temperature detecting element 15 and the sensor coil 45 are not in contact with each other.

When temperature measurement is performed in the temperature measurement system of the third example, first, similarly to the above, after the temperature measurement substrate TW is placed on the heat treatment plate 31, the elevating mechanism 41 lowers the plate cover 40. Next, the switch 21 is switched to the transmitter 22 side, and each of the plurality of sensor coils 45 and the transmitter 22 are connected. Subsequently, a transmission wave having a frequency f ₁ corresponding to the natural frequency of one of the quartz crystal resonators 18 of the seventeen temperature sensing elements 15 attached to the temperature measurement substrate TW is transmitted from the transmitter 22. send. The frequency of the transmitted wave (here, f ₁ ) is transmitted from the transmitter 22 to the temperature calculation unit 89 as an electrical signal. In the temperature measurement system of the third example configured by wireless connection, the natural frequencies of the 17 crystal resonators 18 are different from each other as described above.

A transmission wave from the transmitter 22 is transmitted from the sensor coil 45 toward the temperature measuring element 15 attached to the upper surface of the temperature measurement substrate TW. At this time, the sensor coil 45 above the crystal resonator 18 having the natural frequency corresponding to the frequency of the transmission wave may be selected and transmitted from only the sensor coil 45. As a result of transmitting the transmission wave having the frequency f ₁ from the sensor coil 45, the transmission wave is received by the coil 19 of the temperature sensing element 15 and converted into an electrical signal, and the frequency of the crystal resonators 18 included in the 17 temperature sensing elements 15. quartz oscillator 18 having a natural frequency corresponding to f ₁ resonates at a frequency f _1. Subsequently, the transmission of the transmitter 22 is stopped to stop transmission of the transmission wave, and the switch 21 is switched to the receiver 23 side.

When the transmission wave is stopped, the resonated crystal resonator 18 dampens at a frequency corresponding to the temperature of the temperature measurement substrate TW (more precisely, the temperature at the position where the crystal resonator 18 is attached). . An electric signal resulting from this damped vibration is emitted as an electromagnetic wave through the coil 19. The electromagnetic wave emitted from the coil 19 of the temperature measuring element 15 having the crystal resonator 18 resonated at the frequency f ₁ is received by the sensor coil 45 and transmitted to the receiver 23 as an electric signal. The frequency counter 24 counts the frequency of the electrical signal input to the receiver 23 and transmits the count value to the temperature calculation unit 29. Based on the frequency of the electrical signal counted by the frequency counter 24 (that is, the frequency of the electromagnetic wave received from the crystal resonator 18) and the frequency of the transmission wave transmitted from the transmitter 22, the temperature calculation unit 29 determines the transmission / reception frequency. The change rate is calculated, and the temperature of the temperature measurement substrate TW at the position where the crystal resonator 18 (the crystal resonator 18 resonated at the frequency f ₁ ) is attached is calculated from the change rate. A frequency discriminator for discriminating electromagnetic waves in a predetermined band centered on the frequency corresponding to the transmission wave transmitted from the electromagnetic waves received by the sensor coil 45 may be provided.

Next, the switch 21 is switched again to the transmitter 22 side, and each of the plurality of sensor coils 45 and the transmitter 22 are connected. The transmitter 22 transmits a transmission wave having a frequency f ₂ corresponding to the natural frequency of one of the 17 crystal resonators 18 attached to the temperature measurement substrate TW, which is different from the above. Call from. This transmission wave is also transmitted from the sensor coil 45 to the temperature measuring element 15 attached to the upper surface of the temperature measurement substrate TW. As a result, a crystal oscillator 18 having a natural frequency corresponding to the frequency f ₂ resonates at the frequency f _2. Subsequently, the transmission of the transmitter 22 is stopped to stop transmission of the transmission wave, and the switcher 21 is switched again to the receiver 23 side.

After the transmission of the transmission wave is stopped, the electromagnetic wave emitted from the coil 19 of the temperature measuring element 15 having the crystal resonator 18 resonated at the frequency f ₂ is received by the sensor coil 45 and transmitted to the receiver 23 as an electric signal. The frequency counter 24 counts the frequency of the electrical signal and transmits the count value to the temperature calculation unit 29. Based on the frequency of the electrical signal counted by the frequency counter 24 (that is, the frequency of the electromagnetic wave received from the crystal resonator 18) and the frequency of the transmission wave transmitted from the transmitter 22, the temperature calculation unit 29 determines the transmission / reception frequency. The change rate is calculated, and the temperature of the temperature measurement substrate TW at the position where the crystal resonator 18 (the crystal resonator 18 resonated at the frequency f ₂ ) is attached is calculated from the change rate.

Thereafter, the same procedure is repeated, and the temperature of the temperature measurement substrate TW at the position where each of the 17 temperature measuring elements 15 is attached is sequentially measured. That is, the transmission waves having the frequencies (f ₁ , f ₂ , f ₃ ,..., F ₁₇ ) corresponding to the natural frequencies of the 17 crystal resonators 18 attached to the temperature measurement substrate TW are detected by the sensor. The quartz crystal 18 having a natural frequency corresponding to the frequency is resonated by sequentially transmitting the coil 45 toward the temperature measuring element 15, and after the transmission of the transmission wave is stopped, the crystal resonator 18 is resonated. The electromagnetic wave emitted from the temperature measuring element 15 is received by the sensor coil 45, and the temperature measurement substrate TW at 17 points (where the temperature detecting element 15 is attached) based on the received electromagnetic wave frequency and the transmitted wave frequency. Measuring temperature. As a result, similarly to the first and second examples, the temperature of the temperature measurement substrate TW at the position where the 17 crystal resonators 18 are attached can be calculated individually.

  Even in the above manner, the temperature of the substrate placed on the heat treatment plate 31 can be measured using the temperature measurement substrate TW, as in the first and second examples. Since the plurality of recesses 11 are carved into the substrate surface of the temperature measurement substrate TW and the temperature measuring element 15 is fitted inside each of the recesses 11, the temperature of the substrate can be measured with extremely high accuracy. It is the same.

  Further, in the temperature measurement system of the third example, each of the temperature measuring elements 15 and the transmission / reception unit 20 are wirelessly connected, so that the wiring is further simplified as compared with the second example. . However, in the case of wireless connection, if the natural frequencies of the 17 crystal resonators 18 are set to the same frequency band, the crystal resonators 18 resonate all at once and the received waves interfere with each other. 15, it is necessary to sequentially transmit a transmission wave having a frequency corresponding to each natural frequency, and as a result, the sampling time required for one temperature measurement is the same as in the first and second examples of wired connection. Can be shortened.

<5. Modification>
While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the third example, 17 sensor coils 45 are provided corresponding to the 17 temperature measuring elements 15, but instead of this, one loop antenna is provided on the plate cover 40. Anyway. However, in this case, since the electromagnetic waves from the 17 temperature measuring elements 15 are received in an overlapping manner, it is preferable to provide a frequency discriminator.

  In the above-described embodiment, the 17 temperature measuring elements 15 are attached to the temperature measurement substrate TW. However, the number of the temperature detecting elements 15 and the installation positions (that is, the number of the recessed portions 11 and the number of the forming positions). Can be arbitrary, for example, 32 temperature sensing elements 15 may be attached to one temperature measurement substrate TW, or 64 temperature sensing elements 15 may be attached. Further, the diameter of the temperature measurement substrate TW may be φ200 mm.

  In addition, the temperature measurement system according to the present invention is not only a heat treatment unit that places a substrate on a hot plate and performs heat treatment as long as the substrate to be treated is placed on a heat treatment plate and performs heat treatment, The present invention can also be applied to a cooling processing unit that places a substrate on a cool plate and performs a cooling process. As the heat treatment unit, for example, it can be suitably applied to a processing unit that requires precise temperature management, such as a unit that performs heat treatment after exposure or a unit that performs heat treatment after resist coating.

It is a top view of the board | substrate for temperature measurement of the state which has not attached the temperature sensing element. It is a figure which shows the state which inserts a thermometry element in a recessed part. It is a whole block diagram of the temperature measurement system of a 1st example. It is a principal part block diagram of the temperature measurement system of FIG. It is a whole block diagram of the temperature measurement system of a 2nd example. It is a principal part block diagram of the temperature measurement system of FIG. It is a perspective view of the temperature measuring element used in the 3rd example. It is a whole block diagram of the temperature measurement system of the 3rd example. It is a principal part block diagram of the temperature measurement system of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Concave part 12 Board | substrate side connector 15 Temperature sensing element 18 Crystal oscillator 19 Coil 20 Transmission / reception part 21 Switcher 22 Transmitter 23 Receiver 24 Frequency counter 29 Temperature calculation part 30 Heat processing unit 31 Heat processing plate 40 Plate cover 42 Cover side connector 45 Sensor Coil 50 Coaxial cable TW Temperature measurement board

Claims (7)

A temperature measurement substrate placed on a heat treatment plate for performing heat treatment of a substrate to be treated,
A substrate having a plurality of recesses formed on the surface;
A plurality of temperature sensing elements fitted into the plurality of recesses and having a crystal resonator;
A substrate for temperature measurement, comprising: The temperature measurement substrate according to claim 1,
A temperature measurement substrate characterized in that a weight in a state where the plurality of temperature measuring elements are fitted is equal to a substrate to be processed. A temperature measurement system for measuring the temperature of a substrate placed on a heat treatment plate,
An electrical signal is transmitted to the plurality of temperature sensing elements mounted on the temperature measurement substrate mounted on the heat treatment plate according to claim 1 or 2, and electricity from each of the plurality of temperature sensing elements is transmitted. Transmitting and receiving means for receiving signals;
Temperature calculating means for calculating the temperature of the substrate for temperature measurement based on the frequency of the electrical signal from each temperature sensing element received by the transceiver means;
A temperature measurement system comprising: The temperature measurement system according to claim 3, wherein
The temperature measuring system, wherein the plurality of temperature measuring elements and the transmitting / receiving means are connected by a coaxial cable. The temperature measurement system according to claim 4,
A plate cover covering the heat treatment plate;
Elevating means for elevating and lowering the plate cover;
Further comprising
A board-side connector connected to each of the plurality of temperature sensing elements is provided on the upper surface of the temperature measurement board,
A cover-side connector connected to the transmitting / receiving means is provided on the lower surface of the plate cover,
The temperature measuring system, wherein when the plate cover is lowered by the elevating means, the board side connector and the cover side connector are fitted to connect the plurality of temperature detecting elements and the transmitting / receiving means. The temperature measurement system according to claim 4 or 5,
The temperature measuring system, wherein the transmission / reception means transmits electric signals having the same frequency to the plurality of temperature measuring elements. The temperature measurement system according to claim 3, wherein
A plate cover that covers the heat treatment plate;
The plurality of temperature measuring elements further includes a coil or an antenna connected to a crystal resonator,
The transmission / reception means transmits transmission waves to the plurality of temperature detection elements via transmission / reception antennas provided on the plate cover, and transmits electromagnetic waves from the temperature detection elements to the transmission / reception antennas after stopping transmission of the transmission waves. Temperature measuring system, characterized by receiving via

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