Temperature control device, temperature control method, temperature control program, and wafer manufacturing apparatus

Abstract

This invention provides a temperature control device for epitaxial growth equipment that allows for the simultaneous adjustment of the output and ratio of the heating sections at the center and periphery when heating the object to be measured, thereby enabling the setting of optimal heating section output conditions and achieving efficient production. [Solution] The device comprises a chamber for housing an object to be measured, a heating unit, a chamber window positioned opposite the object to be measured, a central temperature measuring unit for measuring the temperature of the central part of the object to be measured, a peripheral temperature measuring unit for measuring the temperature of the peripheral part of the object to be measured, a identification unit provided in the peripheral temperature measuring unit for identifying the position of the peripheral part of the object to be measured, an adjustment unit for adjusting the measurement direction of the peripheral temperature measuring unit, a calculation unit for calculating the central temperature and peripheral temperature, and an output control unit for controlling the output of the heating unit based on both the central temperature and peripheral temperature.

Description

Technical Field

[0001] The present invention relates to a temperature control device, a temperature control method, a temperature control program, and a wafer manufacturing device, and is a temperature control device, method, and program for indirectly measuring the temperature of each part of a measurement object and controlling heating conditions, and also relates to a wafer manufacturing device including the temperature control device.

Background Art

[0002] In the manufacture of silicon wafers, which are components of semiconductors, epitaxial growth apparatuses are currently widely used. In this apparatus, the silicon wafer is housed in a chamber, and the temperature of the silicon wafer is measured by a pyrometer (radiation thermometer) installed outside the chamber (see Patent Documents 1, 2, 3, 4, 5, etc.).

[0003] Conventionally, the temperature of a silicon wafer has been measured by a pyrometer with a member of the chamber window interposed therebetween. In this temperature measurement, it was a measurement of one point in the region of the central part of the measurement object such as a silicon wafer. However, in the case of heating a silicon wafer, the temperature distribution of the silicon wafer is not always uniform. In order to obtain a desired temperature distribution, the ratio of the output of the heating unit is controlled for each of the upper and lower parts of the silicon wafer, and further for each of the center and the periphery. And the ratio of the output of the heating unit is adjusted so as to become a desired heating condition based on the quality result of the silicon wafer completed after the epitaxial growth process.

[0004] According to the adjustment of the heating conditions described above, the ratio of the output of the heating unit is adjusted reflecting the quality result of the silicon wafer after the manufacturing process has ended. Therefore, it is difficult to set different ratios according to the manufacturing stage, and generally a fixed ratio is set throughout the manufacturing process.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Special Publication No. 2009-507997 [Patent Document 2] Japanese Patent Publication No. 2016-129162 [Patent Document 3] Japanese Patent Publication No. 2018-44915 [Patent Document 4] Japanese Patent Publication No. 2022-144083 [Patent Document 5] Japanese Patent Application Publication No. 9-311081 [Overview of the project] [Problems that the invention aims to solve]

[0006] In controlling the heating conditions as described above, the optimal ratio of the heating unit's output is thought to differ during heating (increasing the output), cooling (decreasing the output), and when the temperature is stable. However, there was no guideline for obtaining the optimal ratio of the heating unit's output, making it difficult to set the ratio.

[0007] For these reasons, in each stage of the manufacturing process, adjustments are made to the heating and cooling rates to maintain the desired silicon wafer quality while keeping the heating unit output ratio consistent, which hinders productivity. Furthermore, since the heating unit output ratio is determined through trial and error, it takes a considerable amount of time to obtain the optimal heating unit output ratio.

[0008] The present invention has been made in view of the above points, and provides a temperature control device, a temperature control method, and a temperature control program for setting optimal heating conditions by allowing the output and ratio of the central and peripheral heating sections to be changed at any time when heating an object to be measured in an epitaxial growth apparatus, thereby realizing efficient production. Furthermore, it provides a wafer manufacturing apparatus that improves the accuracy of temperature control during wafer manufacturing by incorporating a temperature control device. [Means for solving the problem]

[0009] In other words, the temperature control device of the embodiment comprises a chamber that houses an object to be measured, a plurality of heating units that heat the object to be measured through the chamber, a chamber window provided at a position on the chamber facing the object to be measured, a central temperature measuring unit located outside the chamber window that measures the temperature of the central part of the object to be measured through the chamber window, a peripheral temperature measuring unit located outside the chamber window that measures the temperature of the peripheral part of the object to be measured through the chamber window, a identification unit provided in the peripheral temperature measuring unit that identifies the position of the peripheral part of the object to be measured within the chamber, an adjustment unit that adjusts the measurement direction of the peripheral temperature measuring unit based on the identification result of the identification unit, a calculation unit that calculates the central temperature of the object to be measured from the detected value of the central temperature measuring unit and calculates the peripheral temperature of the object to be measured from the detected value of the peripheral temperature measuring unit, and an output control unit that controls the output of the heating units based on both the central temperature and the peripheral temperature.

[0010] Furthermore, the wafer manufacturing apparatus of the embodiment is characterized by comprising: a chamber of an epitaxial growth apparatus that houses a silicon wafer; a plurality of heating units that heat the silicon wafer through the chamber; a chamber window unit provided at a position in the chamber facing the silicon wafer; a center temperature measuring unit located outside the chamber window unit and measuring the temperature of the center of the silicon wafer through the chamber window unit; a peripheral temperature measuring unit located outside the chamber window unit and measuring the temperature of the peripheral part of the silicon wafer through the chamber window unit; a identification unit provided in the peripheral temperature measuring unit that identifies the position of the peripheral part of the silicon wafer within the chamber; an adjustment unit that adjusts the measurement direction of the peripheral temperature measuring unit based on the identification result of the identification unit; a calculation unit that calculates the center temperature of the silicon wafer from the detected value of the center temperature measuring unit and calculates the peripheral temperature of the silicon wafer from the detected value of the peripheral temperature measuring unit; and an output control unit that controls the output of the heating units based on both the center temperature and the peripheral temperature. [Effects of the Invention]

[0011] The temperature control device of the present invention comprises a chamber for housing an object to be measured, a plurality of heating units for heating the object to be measured via the chamber, and a chamber window located in the chamber facing the object to be measured. The device includes a central temperature measuring unit located outside the chamber window for measuring the temperature of the central part of the object to be measured via the chamber window, a peripheral temperature measuring unit located outside the chamber window for measuring the temperature of the peripheral part of the object to be measured via the chamber window, a identification unit located in the peripheral temperature measuring unit for identifying the position of the peripheral part of the object to be measured within the chamber, an adjustment unit for adjusting the measurement direction of the peripheral temperature measuring unit based on the identification result of the identification unit, a calculation unit for calculating the central temperature of the object to be measured from the detected value of the central temperature measuring unit and the peripheral temperature of the object to be measured from the detected value of the peripheral temperature measuring unit, and an output control unit for controlling the output of the heating units based on both the central temperature and the peripheral temperature. Therefore, in an epitaxial growth apparatus, the output and ratio of the central and peripheral heating units can be changed at any time to set optimal output conditions for the heating units, thereby enabling efficient production of the object to be measured. Furthermore, by applying this technology to wafer manufacturing equipment, it is possible to optimally control the heating conditions of the silicon wafer, which is the object to be measured, and achieve efficient production. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a wafer manufacturing apparatus equipped with a temperature control device according to the embodiment. [Figure 2] This is a schematic block diagram showing the configuration of the calculation unit of the temperature control device. [Figure 3] (A) First schematic diagram and (B) Second schematic diagram for temperature measurement of an object being measured. [Figure 4] (A) First schematic diagram and (B) Second schematic diagram are provided to explain the specific conditions of a particular part. [Figure 5] This is a flowchart showing the processing procedure in the temperature measuring device of the embodiment. [Modes for carrying out the invention]

[0013] The temperature control device of this embodiment is mainly connected to wafer manufacturing equipment (specifically, an epitaxial apparatus or epitaxial growth apparatus) that manufactures wafers such as silicon wafers for semiconductors. The temperature control device is used to measure the temperature of the wafer and control the heating conditions when the wafer is epitaxially grown.

[0014] Figure 1 is a schematic diagram of a temperature control device 1 and a wafer manufacturing apparatus 2 equipped with the temperature control device 1 according to an embodiment. Specifically, the wafer manufacturing apparatus 2 is a device that combines a chamber 11 of an epitaxial growth apparatus for epitaxial growth on a silicon wafer with a computer 10. The number of chambers 11 that can be combined with the computer 10 can be one or more as appropriate. For convenience, the illustration shows one chamber 11.

[0015] Chamber 11 is a device (furnace) having a space of an appropriate shape, which generates crystals on the surface of one or more silicon wafers 14 placed on a susceptor 13 inside. The gas necessary for crystal growth is introduced into the chamber 11 from a raw material gas tank (not shown) through a gas inlet passage 16. After a predetermined reaction, the gas is discharged outside the chamber 11 through a gas outlet passage 17. A chamber window 18 made of quartz, which has excellent light transmittance, is installed in the chamber 11. The quartz chamber window 18 is positioned directly above the silicon wafer 14, which is the object to be measured, and faces the silicon wafer 14.

[0016] In chamber 11, heating units 25, 26, 27, 28 that accommodate silicon wafer 14, heat it at a predetermined temperature, maintain the temperature, and react with a gas are installed at appropriate locations outside chamber 11. The heating units are heat sources that generate heat by energizing a halogen lamp, an infrared lamp, or the like. The upper surface side (the upper side in the drawing) of silicon wafer 14 is heated by heating units 25, 26, and the lower surface side (the lower side in the drawing) of silicon wafer 14 is heated by heating units 27, 28. Further, the central portion side of silicon wafer 14 is heated by heating units 26, 28, and the peripheral portion side of silicon wafer 14 is heated by heating units 25, 27. Since a plurality of heating units are installed at different positions, heating corresponding to the portions of silicon wafer 14 is possible.

[0017] For temperature measurement of silicon wafer 14 (measurement object, workpiece) placed on susceptor 13 in chamber 11, a plurality of temperature measurement units (three locations in the drawing) are provided. Central temperature measurement unit 21 (first temperature measurement unit) is a temperature measurement unit that is installed vertically from the central portion 14c of silicon wafer 14 through chamber window portion 18 outside chamber window portion 18 to measure the temperature of the central portion 14c of silicon wafer 14. Peripheral temperature measurement unit 22 (second temperature measurement unit) is a temperature measurement unit that is outside chamber window portion 18 and measures the temperature of the peripheral portion 14e of silicon wafer 14 through chamber window portion 18. Of course, the number of installations of central temperature measurement unit 21 and peripheral temperature measurement unit 22 is not limited to one each shown in the drawing, and a plurality (not shown) may be installed.

[0018] Furthermore, a susceptor temperature measurement unit 24 (third temperature measurement unit) for measuring the temperature of the susceptor 13 in the chamber 11 is installed at an appropriate position in the lower part 12 of the chamber 11. The central temperature measurement unit 21, the peripheral temperature measurement unit 22, and the susceptor temperature measurement unit 24 are non-contact thermometers called pyrometers or the like, and are devices that measure the radiant emittance (radiant heat quantity, emissivity) of an object according to Stefan-Boltzmann's law and Planck's law. Further, a temperature control unit 23 is provided to cool the chamber 11 from heating by the heating unit 25 or the like to suppress excessive heating in the chamber window portion 18. The temperature control unit 23 is a device such as a blower that blows air onto the surface of the chamber 11.

[0019] The peripheral temperature measurement unit 22 is provided with a specifying unit 30. The specifying unit 30 is a device that specifies the position of the peripheral portion 14e of the silicon wafer 14 while the silicon wafer 14 is being heated in the chamber 11. By specifying the peripheral portion 14e of the silicon wafer 14, the specifying unit 30 confirms whether the measurement direction of the peripheral temperature measurement unit 22 is appropriate. And an adjustment unit 110 is provided to adjust the measurement direction of the peripheral temperature measurement unit 22 based on the specifying result of the specifying unit 30. The measurement direction of the peripheral temperature measurement unit 22 is, of course, inside the peripheral portion 14e of the silicon wafer 14. The specifying unit 30 and the peripheral temperature measurement unit 22 are supported above the chamber 11 in a wafer manufacturing apparatus 2 provided with a temperature control device 1 so as to be swingable. Therefore, the peripheral temperature measurement unit 22 changes (swings) a necessary amount of angle at a shaft portion (not shown) that supports the peripheral temperature measurement unit 22 in accordance with the rotation of the silicon wafer 14 on the susceptor 13.

[0020] The identification unit 30 is a identification device, such as a laser sight. A laser is shone from the identification unit 30 onto the peripheral portion 14e of the target silicon wafer 14, and the reflected light from the target is received. From the change in the amount of received light, it is confirmed whether the measurement direction of the ambient temperature measurement unit 22 is facing the peripheral portion 14e of the silicon wafer 14. The identification unit 30 is equipped with a drive mechanism 31 (see Figure 3), such as a servo motor. Based on the results from the identification unit 30, the drive mechanism 31 is activated based on the control of the computer 10 (adjustment unit 110, which will be described later), and the angle of the ambient temperature measurement unit 22 is corrected so that the measurement direction of the ambient temperature measurement unit 22 is facing the peripheral portion 14e of the silicon wafer 14.

[0021] As shown in the schematic diagram of Figure 3, when measuring the temperature of the silicon wafer 14, which is the object to be measured, from outside the chamber 11 using a central temperature measuring unit 21 such as a pyrometer and a peripheral temperature measuring unit 22, the radiance measured by the central temperature measuring unit 21 includes the radiance of the silicon wafer 14 as well as the radiance originating from the chamber window portion 18 that constitutes the chamber 11, and the radiance of both mixed together is detected as the detected value. Here, the chamber window portion 18 is made of quartz and has a uniform material. It is possible to calculate the radiance originating from the quartz chamber window portion 18 from the heating conditions for the silicon wafer 14, which is the object to be measured. Therefore, the total radiance is first calculated through the central temperature measuring unit 21, and then the influence of the radiance originating from the quartz chamber window portion 18 is excluded through conversion data, and finally the temperature of the silicon wafer 14, which is the object to be measured, can be measured.

[0022] As shown in Figure 3(A), the center temperature measurement unit 21 is installed directly above the center 14c of the silicon wafer 14, with the chamber window 18 in between. Since the center 14c of the silicon wafer 14 does not shift significantly on the susceptor 13, the center temperature measurement unit 21 is installed in a fixed position.

[0023] In Figure 3(B), the ambient temperature measurement unit 22 is installed on the periphery 14e of the silicon wafer 14, with the chamber window 18 in between. As described above, the ambient temperature measurement unit 22 is equipped with a specific unit 30, and the measurement direction, i.e., the angle of the ambient temperature measurement unit 22 is appropriately changed and controlled by the drive mechanism 31 (servo motor, etc.) of the specific unit 30 (see the solid and dashed lines in the figure).

[0024] The schematic diagram in Figure 4 shows the specific unit 30 of the laser sight and the peripheral portion 14e of the silicon wafer 14. The thick solid line represents the edge of the silicon wafer 14 and indicates the peripheral portion 14e. The circle Ec shown indicates the measurement area of ​​the peripheral temperature measurement unit 22 and represents the range of the laser irradiated from the laser sight of the specific unit 30 onto the peripheral portion 14e of the target silicon wafer 14. The specific unit 30 of the laser sight is equipped with a camera that captures reflected light from the silicon wafer 14.

[0025] In Figure 4(A), the circle Ec representing the range of the irradiated laser extends beyond the peripheral area 14e, potentially leading to the measurement of temperatures other than those of the silicon wafer 14 and reducing the accuracy of temperature measurement.

[0026] In Figure 4(B), the circle Ec representing the range of the laser beam irradiated from the laser sight of the specific unit 30 onto the peripheral portion 14e of the target silicon wafer 14 is further inward than the peripheral portion 14e compared to Figure 4(A). As a result, circle Ec is inward of the peripheral portion 14e, meaning the measurement target range is contained within the area inward of the peripheral portion 14e. Therefore, the temperature of the peripheral portion 14e of the silicon wafer 14 can be accurately measured by the ambient temperature measurement unit 22.

[0027] Since the silicon wafer 14 on the susceptor 13 in the chamber 11 is not necessarily placed in line with the rotation axis of the susceptor 13 (centered), the silicon wafer 14 may move out of the measurement direction of the ambient temperature measurement unit 22 when the susceptor 13 rotates during epitaxial growth. Therefore, a specific unit 30 and an adjustment unit 110 are provided, which allow the measurement direction of the ambient temperature measurement unit 22 to follow the peripheral portion 14e of the silicon wafer 14 as a reference, thereby realizing accurate temperature measurement of the peripheral portion 14e of the silicon wafer 14.

[0028] In the coordination between the aforementioned specific unit 30 and the adjustment unit 110 described later, for example, the silicon wafer 14, which is the object to be measured, is placed in a predetermined position inside the chamber 11 beforehand, and a laser is irradiated from the specific unit 30 onto the peripheral portion 14e of the silicon wafer 14, and the measurement direction of the ambient temperature measurement unit 22 is adjusted. The adjustment method may be controlled by the computer 100 described later, or by offline control. In addition, a scale or gauge for adjusting the position and angle may be attached to the ambient temperature measurement unit 22. The results of the laser irradiation of the peripheral portion 14e of the silicon wafer 14 from the specific unit 30 in advance are stored, and the ambient temperature measurement unit 22 is set to a position and angle that matches the results. In this way, sequential laser irradiation from the specific unit 30 each time can be omitted.

[0029] In the wafer manufacturing apparatus 2, the core temperature measurement unit 21, the ambient temperature measurement unit 22, the susceptor temperature measurement unit 24, the temperature control unit 23, the heating units 25, 26, 27, 28, the specific unit 30, etc., are connected to the computer 10, and signals are transmitted between them. Note that the wiring for power supply to each temperature measurement unit 21, 22, 24, temperature control unit 23, and heating units 25, 26, 27, 28 is not shown in the diagram.

[0030] The temperature control device 1 calculates the temperature of the object to be measured, such as a silicon wafer 14, from the detected values ​​of the core temperature measurement unit 21, the ambient temperature measurement unit 22, and the susceptor temperature measurement unit 24. Therefore, the temperature control device 1 is equipped with a known computer 10 capable of performing calculations. As shown in the block diagram of Figure 2, the computer 10 is hardware-wise equipped with an arithmetic unit 101 (CPU, GPU, etc.), ROM 102, RAM 103, storage unit 104, etc., and is appropriately equipped with I / O (input-output-interface) 105, etc. The computer 10 is composed of various electronic computers (computational resources), such as known personal computers, supercomputers, mainframes, workstations, and cloud computing systems.

[0031] Furthermore, as shown in Figure 1, the computer 10 is equipped with an output display (monitor) 4, an input keyboard 5, and a mouse 6. These are connected to the I / O 105. The core temperature measurement unit 21, ambient temperature measurement unit 22, susceptor temperature measurement unit 24, temperature control unit 23, and heating units 25, 26, 27, and 28 disclosed in Figure 1 are also connected to the I / O 105.

[0032] When each function of the computer 10 of the temperature control device 1 is implemented by software, the computer 10 is implemented by executing instructions for a program, which is the software that implements each function. The recording medium for storing this program can be a "non-temporary tangible medium," such as a CD, DVD, semiconductor memory, or programmable logic circuit. This program may also be supplied to the computer 10 of the temperature control device 1 via any transmission medium capable of transmitting the program (such as a communication network or broadcast waves).

[0033] The storage unit 104 of the computer 10 of the temperature control device 1 is equipped with a storage device such as an HDD or SSD. Alternatively, the storage unit 104 may be an external server (not shown). The storage unit 104 stores various data, information, programs, and various data necessary for the execution of those programs.

[0034] The functional units of the calculation unit 101 of the computer 10 of the temperature control device 1 are shown in the schematic block diagram of Figure 2. Each functional unit includes an adjustment unit 110, a calculation unit 120, and an output control unit 130. An output unit is also provided to perform the processing necessary for output. Processing and execution in the temperature control device 1 and wafer manufacturing apparatus 2 are realized software-wise by a temperature measurement program loaded into the main memory.

[0035] The adjustment unit 110 adjusts the measurement direction of the ambient temperature measurement unit 22 based on the identification result of the identification unit 30. Based on the identification result of the identification unit 30, if the measurement direction of the ambient temperature measurement unit 22 remains unchanged, no special control is performed by the adjustment unit 110. If the adjustment unit 110 needs to calibrate the measurement direction of the ambient temperature measurement unit 22 based on the identification result, it generates information on the amount of operation (motor rotation amount) of the drive mechanism 31, such as a servo motor, provided in the identification unit 30. The adjustment unit 110 then transmits a control signal to the identification unit 30, and the identification unit 30 drives with the amount of operation based on the control signal. As a result, the measurement direction of the ambient temperature measurement unit 22 is adjusted to face the peripheral portion 14e of the silicon wafer 14. Refer to the explanations of Figures 3 and 4 above. That is, the peripheral portion 14e of the silicon wafer 14 is identified in the image captured by the identification unit 30. The circle Ec in Figure 4 (the measurement area of ​​the ambient temperature measurement unit 22) is adjusted to be located within the arc of the peripheral portion 14e and at a predetermined distance from the end.

[0036] The operation and processing of the adjustment unit 110 can be broadly classified into two types. The first is a pre-setting mode in which the measurement direction of the ambient temperature measurement unit 22 is adjusted based on the laser irradiation of the peripheral portion 14e of the target silicon wafer 14 from the specific unit 30, as described above. In the first mode, the repositioning of the ambient temperature measurement unit 22 each time is omitted, simplifying the entire process. The second is a mode in which the position and angle of the silicon wafer 14 are successively corrected with respect to the silicon wafer 14 during processing (epitaxial growth process) of the silicon wafer 14 on the susceptor 13 in the chamber 11. In the second mode, the repositioning of the ambient temperature measurement unit 22 is performed precisely even during the process, so the temperature measurement of the silicon wafer 14 becomes more accurate.

[0037] The calculation unit 120 calculates the central temperature (Tc) (temperature near the central part 14c) of the silicon wafer 14 from the detected value of the central temperature measurement unit 21. At the same time, the calculation unit 120 calculates the peripheral temperature (Tp) (temperature near the peripheral part 14e) of the silicon wafer 14 from the detected value of the peripheral temperature measurement unit 22. More specifically, the calculation unit 120 estimates the target temperature change of the silicon wafer 14 by excluding the influence of the radiance amount caused by the chamber window from the measured temperature change amount calculated from the detected values ​​of each temperature measurement unit. Then, the calculation unit 120 generates conversion data from the correlation between the measured temperature change amount and the target temperature change amount.

[0038] The measured temperature change calculated from the detected values ​​of temperature measuring units such as the core temperature measuring unit 21 and the ambient temperature measuring unit 22 is a measurement of the so-called apparent temperature change. However, it is obvious that this does not necessarily match the actual temperature of the silicon wafer 14 inside the chamber 11. In particular, since the chamber window portion 18 is located between the core temperature measuring unit 21 and the ambient temperature measuring unit 22 and the silicon wafer 14, the influence of radiant heat from the chamber window portion 18 is unavoidable. Strictly speaking, there is a discrepancy between the measured temperature in the heated state and the temperature of the silicon wafer 14. The calculation unit 120 may generate conversion data to correct (calibrate) such a temperature discrepancy.

[0039] The output control unit 130 controls the output of the heating units 25, 26, 27, and 28 based on both the core temperature (Tc) and the peripheral temperature (Tp). Since the heating units are heat sources such as halogen lamps, the output control involves increasing or decreasing the amount of power supplied to each heating unit. In the temperature control device 1 and wafer manufacturing apparatus 2 of this embodiment, the output of each of the heating units 25, 26, 27, and 28 is controlled independently.

[0040] The output control method by the output control unit 130 may be feedback control from both the core temperature (Tc) and the peripheral temperature (Tp). Since the temperature control of the heating units 25, 26, 27, and 28 can be performed by reflecting the core temperature (Tc) and peripheral temperature (Tp) obtained from the measured values ​​(corrected), the response time is increased. Alternatively, temperature control by output control of the heating units 25, 26, 27, and 28 may be performed by considering the measured values ​​(corrected) from the susceptor temperature measurement unit 24.

[0041] Furthermore, the output control unit 130 can control the output of the heating units 25, 26, 27, and 28 by using either the core temperature (Tc) or the peripheral temperature (Tp) instead of both, and then performing feedback control. If the measurement result of either the core temperature (Tc) or the peripheral temperature (Tp) can substitute for (convert) the result of the other, then only one can be used instead of both.

[0042] In feedback control based on both the core temperature (Tc) and the peripheral temperature (Tp), the heating elements corresponding to the core temperature (Tc) and the peripheral temperature (Tp) are independently temperature-controlled based on each measured value. In addition, the heating elements corresponding to the core temperature (Tc) and the peripheral temperature (Tp) are temperature-controlled by maintaining a constant temperature difference (ΔT = Tc - Tp) between the core temperature (Tc) and the peripheral temperature (Tp).

[0043] Furthermore, in feedback control from both the core temperature (Tc) and the peripheral temperature (Tp), the ratio of the output values ​​(watts) between multiple heating elements in the area corresponding to the core temperature (Tc) and peripheral temperature (Tp) may be maintained at a constant condition based on each measured value, and this control may be applied accordingly.

[0044] As shown in Figure 1, the central part of the silicon wafer 14 is heated by heating units 26 and 28, and the peripheral part of the silicon wafer 14 is heated by heating units 25 and 27. For example, the output ratio (Pu = Pup / Puc) of the output of heating unit 26 (Puc) and heating unit 25 (Pup) on the upper side of the silicon wafer 14 is defined. Of course, the same applies to the lower side of the silicon wafer 14 (the output ratio between heating units 28 and 27). In addition, the output ratio between the upper and lower heating units on the central side of the silicon wafer 14 (the output ratio between heating units 26 and 28 in the figure) and the output ratio between the upper and lower heating units on the peripheral side of the silicon wafer 14 (the output ratio between heating units 25 and 27 in the figure) can also be defined.

[0045] In the epitaxial growth reaction on the silicon wafer 14, the central temperature (Tc) and the peripheral temperature (Tp) do not always need to be exactly the same, depending on the positional relationship of the heating units 25, 26, 27, and 28. A temperature difference (ΔT) is acceptable as long as it does not hinder manufacturing. Therefore, the temperature difference (ΔT) between the central temperature (Tc) and the peripheral temperature (Tp) is monitored, and temperature control that maintains the temperature difference (ΔT) is achieved through output control for each heating unit 25, 26, 27, and 28. In particular, the epitaxial growth reaction involves processes of heating, temperature maintenance, and cooling. Therefore, by maintaining the temperature difference (ΔT) between the central temperature (Tc) and the peripheral temperature (Tp) during processes involving temperature changes, the quality of the epitaxial growth of the silicon wafer 14 is stabilized.

[0046] In addition, since the output ratio between heating units is set individually, direct heating control of the silicon wafer 14 is possible through the heating units. Therefore, it is suitable for control when it is necessary to raise or lower the temperature while maintaining the output ratio between heating units.

[0047] Thresholds are set for the temperature difference (ΔT) between the core temperature (Tc) and the peripheral temperature (Tp), and for the power output ratio (Pu, etc.) between the heating elements on the same side of the silicon wafer 14, or between the upper and lower parts of the silicon wafer 14. In the production of epitaxial growth on silicon wafers 14, variations in equipment, measurement errors, and fluctuations in manufacturing conditions are unavoidable. Therefore, variations in temperature differences and power output ratios within a range that does not cause problems in manufacturing are permitted. However, from the viewpoint of ensuring quality, thresholds (values ​​with a range of lower and upper limits) are set as acceptable limits. When a condition deviates from the threshold, the silicon wafer 14 being manufactured may be rejected as a defective product. Alternatively, a limit may be set as a control value and manufacturing may continue.

[0048] Next, using the flowchart in Figure 5, the temperature control program in the computer 10 (arithmetic unit 101) of the temperature control device 1 and wafer manufacturing apparatus 2 of this embodiment will be explained. The temperature control method is executed by the arithmetic unit 101 (arithmetic elements) of the computer 10 based on the temperature control program.

[0049] The temperature control program instructs the computer 10 in Figure 2 to execute adjustment functions, calculation functions, output control functions, etc. Although not explained in detail, necessary functions for the device, such as output functions, are naturally included and executed. Since each function overlaps with the description of the temperature control device 1 above, details are omitted.

[0050] As shown in the flowchart of Figure 5, the processing of the arithmetic unit 101 (arithmetic elements) of the computer 10 includes various steps such as the adjustment step (S110), the calculation step (S120), and the output control step (S130). Of course, the various steps necessary for the operation of the computer 10 itself are naturally included.

[0051] The adjustment function adjusts the measurement direction of the ambient temperature measurement unit 22 based on the identification result of the identification unit 30 (S110; adjustment step). The calculation function calculates the central temperature of the silicon wafer 14, which is the object to be measured, from the detected value of the central temperature measurement unit 21, and also calculates the peripheral temperature of the silicon wafer 14 from the detected value of the ambient temperature measurement unit 22 (S120; calculation step). The output control function controls the output of the heating units 25, 26, 27, and 28 based on both the central temperature and the peripheral temperature.

[0052] The computer program of the present invention described above may be recorded on a processor-readable recording medium, and as the recording medium, a "non-temporary tangible medium" such as a disk, card, semiconductor memory, or programmable logic circuit can be used.

[0053] The above computer program can be implemented using, for example, scripting languages ​​such as ActionScript and JavaScript®, object-oriented programming languages ​​such as Objective-C and Java®, and markup languages ​​such as HTML5. [Explanation of Symbols]

[0054] 1. Temperature control device 2. Wafer manufacturing equipment 4. Display (Monitor) 10 Computers 11 Chambers 12 Lower part of chamber 13 Susceptors 14 silicon wafers 14c center 14e Peripheral area 16 Gas inlet 17 Gas Outlet 18 Chamber window section 21 Core temperature measurement unit 22 Ambient temperature measurement unit 23 Temperature control section 24 Susceptor Temperature Measurement Unit 25,26,27,28 Heating section 30 Specific section 31 Drive mechanism 101 Arithmetic section 102 ROM 103 RAM 104 Storage section 105 I / O 110 Adjustment section 120 Calculation Unit 130 Output control unit

Claims

1. A temperature control device for an epitaxial growth apparatus comprising a chamber for housing an object to be measured, a plurality of heating units for heating the object to be measured via the chamber, and a chamber window provided at a position in the chamber facing the object to be measured, A central temperature measuring unit located outside the chamber window portion and measuring the temperature of the central part of the object to be measured via the chamber window portion, A peripheral temperature measuring unit located outside the chamber window portion and measuring the temperature of the area surrounding the object to be measured via the chamber window portion, The ambient temperature measurement unit is provided with a specification unit that identifies the position of the peripheral part of the object to be measured within the chamber, An adjustment unit that adjusts the measurement direction of the ambient temperature measurement unit based on the identification result of the specified unit, A calculation unit that calculates the central temperature of the object to be measured from the detected value of the central temperature measuring unit, and calculates the peripheral temperature of the object to be measured from the detected value of the peripheral temperature measuring unit, The system includes an output control unit that controls the output of the heating unit based on both the central temperature and the peripheral temperature. A temperature control device characterized by the following features.

2. The temperature control device according to claim 1, wherein a laser sight is provided in the specified portion, and the position of the peripheral portion is determined based on the laser light emitted by the laser sight.

3. The temperature control device according to claim 1, wherein a plurality of heating units are installed in the upper and lower parts of the chamber, respectively, and the object to be measured is heated from above and below.

4. The temperature control device according to claim 1, wherein the output control unit controls the output of the heating unit by feedback control based on either the central temperature or the peripheral temperature.

5. The temperature control device according to claim 4, wherein the output control unit controls the output of the heating unit to the central part and the peripheral part of the object to be measured by feedback control of the temperature difference between the central part temperature and the peripheral part temperature.

6. The temperature control device according to claim 5, wherein the temperature difference between the central temperature and the peripheral temperature is set to be within a predetermined threshold range.

7. The temperature control device according to claim 3, wherein the output control unit controls the ratio of output between the heating units of the part of the object to be measured corresponding to the central temperature and the peripheral temperature, based on the central temperature and the peripheral temperature.

8. The temperature control device according to claim 7, wherein the ratio of the output is set within a predetermined threshold range.

9. The temperature control device according to claim 1, wherein the object to be measured is a silicon wafer.

10. The aforementioned identification unit is provided in the ambient temperature measuring unit and identifies the position of the peripheral part of the object to be measured while the object to be measured is being heated in the chamber. The temperature control device according to claim 1, wherein the adjustment unit adjusts the measurement direction of the ambient temperature measurement unit in accordance with the result of the specification unit.

11. A chamber that houses the object to be measured, Multiple heating units that heat the object to be measured via the chamber, A chamber window is provided at the position of the chamber facing the object to be measured, A central temperature measuring unit located outside the chamber window portion and measuring the temperature of the central part of the object to be measured via the chamber window portion, A peripheral temperature measuring unit located outside the chamber window portion and measuring the temperature of the area surrounding the object to be measured via the chamber window portion, A temperature control method for an epitaxial growth apparatus, comprising: an ambient temperature measuring unit provided with a identifying unit that identifies the position of the peripheral part of the object to be measured within the chamber, The temperature control device is An adjustment step to adjust the measurement direction of the ambient temperature measuring unit based on the identification result of the specified unit, A calculation step which involves calculating the central temperature of the object to be measured from the detected value of the central temperature measuring unit, and calculating the peripheral temperature of the object to be measured from the detected value of the peripheral temperature measuring unit, The output control step of controlling the output of the heating unit based on both the central temperature and the peripheral temperature is performed. A temperature control method characterized by the following:

12. A chamber that houses the object to be measured, Multiple heating units that heat the object to be measured via the chamber, A chamber window is provided at the position of the chamber facing the object to be measured, A central temperature measuring unit located outside the chamber window portion and measuring the temperature of the central part of the object to be measured via the chamber window portion, A peripheral temperature measuring unit located outside the chamber window portion and measuring the temperature of the area surrounding the object to be measured via the chamber window portion, A temperature control program for a temperature control device for an epitaxial growth apparatus, comprising: an ambient temperature measuring unit provided with a identifying unit that identifies the position of the peripheral part of the object to be measured within the chamber, The temperature control device is An adjustment function that adjusts the measurement direction of the ambient temperature measuring unit based on the identification result of the specified unit, A calculation function that calculates the central temperature of the object to be measured from the detected value of the central temperature measuring unit, and calculates the peripheral temperature of the object to be measured from the detected value of the peripheral temperature measuring unit, An output control function is implemented that controls the output of the heating unit based on both the central temperature and the peripheral temperature. A temperature control program characterized by the following features.

13. A chamber of an epitaxial growth apparatus that houses a silicon wafer inside, A plurality of heating units that heat the silicon wafer through the chamber, A chamber window portion is provided at the position of the chamber facing the silicon wafer, A central temperature measuring unit located outside the chamber window portion and measuring the temperature of the central part of the silicon wafer through the chamber window portion, A peripheral temperature measuring unit located outside the chamber window portion and measuring the temperature of the peripheral portion of the silicon wafer through the chamber window portion, The ambient temperature measurement unit is provided with a identification unit that identifies the position of the peripheral part of the silicon wafer within the chamber, An adjustment unit that adjusts the measurement direction of the ambient temperature measurement unit based on the identification result of the specified unit, A calculation unit that calculates the temperature of the central part of the silicon wafer from the detected value of the central temperature measurement unit and the temperature of the peripheral part of the silicon wafer from the detected value of the peripheral temperature measurement unit, The system includes an output control unit that controls the output of the heating unit based on both the central temperature and the peripheral temperature. A wafer manufacturing apparatus characterized by the following features.

14. The wafer manufacturing apparatus according to claim 13, wherein a laser sight is provided in the specified portion, and the position of the peripheral portion is determined based on the laser light emitted by the laser sight.

15. The wafer manufacturing apparatus according to claim 13, wherein a plurality of heating units are installed in the upper and lower parts of the chamber, respectively, and the silicon wafer is heated from above and below.

16. The aforementioned identification unit is provided in the ambient temperature measurement unit and identifies the position of the peripheral part of the silicon wafer while the silicon wafer is being heated in the chamber. The wafer manufacturing apparatus according to claim 13, wherein the adjustment unit adjusts the measurement direction of the ambient temperature measurement unit in accordance with the result of the specification unit.

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