Temperature measurement device, temperature measurement method, and temperature measurement program, and wafer production apparatus

Abstract

Provided is a temperature measurement device for, in a situation where the temperature of a silicon wafer which is a measurement target is indirectly measured, removing, from actually measured radiance, the effects of radiance coming from a chamber member, and calculating the amount of change in the temperature of the measurement target. The temperature measurement device comprises: a chamber for accommodating a measurement target object; a heating unit; a chamber window at a position in the chamber opposite from the measurement target object; a temperature measurement unit for measuring the temperature of the measurement target object and the chamber window; and a computation unit for calculating the temperature of the measurement target object from detected values of the temperature measurement unit. The computation unit is provided with: a conversion unit for generating, from actually measured temperatures calculated from the detected values of the temperature measurement unit, conversion data pertaining to the amount of change in the temperature of the measurement target object corresponding to the amount of change in the temperature of the chamber window; a condition acquisition unit for acquiring a condition under which the measurement target object is heated; a detected value acquisition unit for acquiring a detected value of the temperature measurement unit; and a temperature correction unit for estimating the temperature of the measurement target object by using the conversion data to correct an actually measured temperature calculated from the detected value of the temperature measurement unit.

Description

Temperature measurement device, temperature measurement method, temperature measurement program, and wafer manufacturing device

[0001] The present invention relates to a temperature measurement device, a temperature measurement method, a temperature measurement program, and a wafer manufacturing apparatus, and is a temperature measurement device, a method, and a program for measuring temperature while excluding the influence of radiant heat from surrounding components when indirectly measuring the temperature of an object to be measured, as well as a wafer manufacturing apparatus equipped with the temperature measurement device.

[0002] Currently, epitaxial growth equipment is widely used in the manufacture of silicon wafers, which are components of semiconductors. In this equipment, 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, etc.).

[0003] In conventional systems, the temperature of the silicon wafer is measured by a pyrometer sandwiched between the chamber window material. Therefore, the actual temperature measured is not purely the temperature of the silicon wafer being measured, but is a measurement value that also includes the radiant heat (radiance) of the chamber window material.

[0004] In the case of epitaxial growth reactions on silicon wafers, precise control of the heating temperature is required according to the type and flow rate of the gas passed into the chamber. However, the current method relies on indirect temperature measurement. As the processing precision required of silicon wafers is now becoming more precise, variations in the epitaxial growth reaction also affect quality and yield. Therefore, there is a need for a method that uses indirect temperature measurement while measuring the temperature of the silicon wafer as purely as possible.

[0005] JP-T-2009-507997 A JP-A-2016-129162 A JP-A-2018-44915 A JP-A-2022-144083 A

[0006] The present invention has been made in consideration of the above points, and provides a temperature measurement device, a temperature measurement method, and a temperature measurement program that, in a situation where the temperature of a silicon wafer to be measured is indirectly measured, more accurately calculates the amount of change in temperature of the object to be measured by excluding the influence of radiance caused by chamber components from the actually measured radiance, and further provides a wafer manufacturing apparatus that is equipped with a temperature measurement device and thereby improves the accuracy of temperature control during wafer manufacturing.

[0007] That is, the temperature measurement device of the embodiment comprises a chamber of an epitaxial growth apparatus that accommodates an object to be measured inside, a heating unit that heats the object to be measured, a chamber window provided in a position of the chamber opposite the object to be measured, a temperature measurement unit that is installed outside the chamber window of the epitaxial growth apparatus and measures the temperature of the object to be measured through the chamber window and the temperature of the chamber window, and a calculation unit that calculates the temperature of the object to be measured from the detection value of the temperature measurement unit, and the calculation unit is characterized by comprising a conversion unit that generates conversion data of the amount of temperature change of the object to be measured heated in the chamber corresponding to the amount of temperature change of the chamber window from the actual measured temperature calculated from the detection value of the temperature measurement unit, a condition acquisition unit that acquires the heating conditions for the object to be measured in the chamber, a detection value acquisition unit that acquires the detection value of the temperature measurement unit, and a temperature correction unit that uses the conversion data to correct the actual measured temperature calculated from the detection value of the temperature measurement unit to estimate the temperature of the object to be measured.

[0008] and a temperature correction unit that estimates the temperature of the silicon wafer by using the conversion data. The conversion data is used to calculate the temperature of the silicon wafer ...

[0009] Furthermore, the wafer manufacturing apparatus may be provided with a temperature control unit outside the chamber that cools the chamber, and the calculation unit may be provided with a temperature control unit that controls the output of the temperature control unit based on the temperature of the silicon wafer estimated by the temperature correction unit.

[0010] According to the temperature measurement device of the present invention, there is provided a chamber of an epitaxial growth apparatus that accommodates an object to be measured therein, a heating unit that heats the object to be measured, a chamber window that is provided in the chamber at a position opposite the object to be measured, a temperature measurement unit that is installed outside the chamber window of the epitaxial growth apparatus and that measures the temperature of the object to be measured through the chamber window and the temperature of the chamber window, and a calculation unit that calculates the temperature of the object to be measured from the detection value of the temperature measurement unit. The calculation unit includes a conversion unit that generates conversion data for the amount of temperature change of the object to be measured that corresponds to the amount of temperature change of the chamber window from the actual measured temperature calculated from the detection value of the temperature measurement unit, a condition acquisition unit that acquires the heating conditions for the object to be measured in the chamber, a detection value acquisition unit that acquires the detection value of the temperature measurement unit, and a temperature correction unit that uses the conversion data to correct the actual measured temperature calculated from the detection value of the temperature measurement unit to estimate the temperature of the object to be measured.Therefore, in a situation where the temperature of the silicon wafer to be measured is indirectly measured, the amount of temperature change of the object to be measured can be calculated more accurately by excluding the influence of radiance due to the components of the chamber from the actually measured radiance. Furthermore, by applying the present invention to a wafer manufacturing device, the amount of temperature change in a silicon wafer, which is the object to be measured, can be accurately calculated.

[0011] 1 is a schematic configuration diagram of a wafer manufacturing apparatus equipped with a temperature measurement device of an embodiment. FIG. 2 is a schematic block diagram showing the configuration of a calculation unit of the temperature measurement device. FIG. 3 is a schematic block diagram showing the functional configuration of the calculation unit of FIG. 2. FIG. 4 is a conceptual diagram when measuring the temperature of a measurement object. FIG. 5 is a graph related to the operation of a temperature adjustment unit of a chamber window, where (a) is a graph showing the output of a heating unit (halogen lamp) when the output of the temperature adjustment unit is intentionally changed in stages under control by the temperature measurement unit to maintain the temperature of the measurement object wafer constant, (b) is a graph of the temperature change of the chamber window measured by the temperature measurement unit at that time, and (c) is a graph showing the relationship between the temperature of the chamber window and the total output of the heating unit (halogen lamp). FIG. 6 is a graph calculated by setting conditions to determine how much the temperature of the measurement object wafer changes when the temperature of the chamber window changes. FIG. 7 is a flowchart showing a processing procedure in a temperature measurement device of an embodiment. FIG. 8 is a demonstration example of temperature measurement of an embodiment, where (a) is a graph showing the measured temperature of a first temperature measurement unit and the speed of the temperature adjustment unit, and (b) is a graph showing the measured temperature of the first temperature measurement unit and the measured temperature of a second temperature measurement unit. 9A and 9B are graphs showing a comparison between the temperature measured by the first temperature measuring unit and the temperature control unit when the coefficient is changed from that shown in FIG. 8, and the temperature measured by the first temperature measuring unit and the temperature measured by the second temperature measuring unit when the coefficient is changed from that shown in FIG. 9A and 9B are graphs showing a comparison between the temperature measured by the first temperature measuring unit and the temperature measured by the second temperature measuring unit when the coefficient is changed from that shown in FIG. 9A and 9B.

[0012] The temperature measurement device of the embodiment is connected to a wafer manufacturing apparatus (specifically, an epitaxial apparatus or an epitaxial growth apparatus) that mainly manufactures wafers such as silicon wafers for semiconductors, and is used to measure the temperature of the wafer and control the heating conditions when the wafer is epitaxially grown.

[0013] 1 is a schematic diagram of a temperature measurement device 1 according to an embodiment and a wafer manufacturing apparatus 2 equipped with the temperature measurement device 1. That is, the wafer manufacturing apparatus 2 is an apparatus that combines a chamber 11 of an epitaxial growth apparatus that performs epitaxial growth on silicon wafers with a computer 10. The number of chambers 11 that can be combined with the computer 10 can range from one to multiple. For convenience, the illustration shows one chamber 11.

[0014] The chamber 11 has a space of an appropriate shape and is an apparatus (furnace) for growing crystals on the surfaces of one to multiple silicon wafers 14 placed on an internal susceptor 13. Gases necessary for crystal growth are introduced into the chamber 11 from a source gas tank (not shown) through a gas inlet path 16. After a predetermined reaction, the gas is discharged to the outside of the chamber 11 through a gas outlet path 17. The chamber 11 is equipped with a chamber window 18 made of quartz, which has excellent light transmittance. The quartz chamber window 18 (quartz dome) is positioned directly above the silicon wafer 14, which is the object to be measured, and faces the silicon wafer 14.

[0015] In the chamber 11, heating units 25, 26, 27, and 28 for heating the silicon wafer 14 to a predetermined temperature and maintaining that temperature to cause it to react with the gas are installed at appropriate locations outside the chamber 11. The heating units are heat sources that generate heat when electricity is applied, such as halogen lamps or infrared lamps.

[0016] A temperature measurement unit (first temperature measurement unit) 21 is installed outside the chamber 11, specifically, directly above the chamber window 18, to measure the temperature of the silicon wafer 14 (measurement object, workpiece) placed on the susceptor 13 of the chamber 11. A temperature measurement unit (second temperature measurement unit) 22 is installed at an appropriate location outside the chamber 11 to measure the temperature of the chamber window 18 itself. Furthermore, a temperature measurement unit 24 (third temperature measurement unit) for measuring the temperature of the susceptor 13 inside the chamber 11 is installed at an appropriate location in the lower part 12 of the chamber 11. The temperature measurement units 21, 22, and 24 are non-contact thermometers known as pyrometers or the like, and are devices that measure the radiance (amount of radiant heat, emissivity) of an object using the Stefan-Boltzmann law and Planck's law. Furthermore, a temperature control unit 23 is provided to cool the chamber 11 from heating by the heater 25 or the like, thereby suppressing excessive heating inside the chamber window 18. The temperature control unit 23 is a device such as a blower that blows air onto the surface of the chamber 11 .

[0017] In the illustrated temperature measurement device 1 and wafer manufacturing apparatus 2, the temperature measurement unit 21 is disposed outside the chamber window 18 installed in the chamber 11, and is used to measure the temperature of the silicon wafer 14, which is the measurement object, through the chamber window 18. In addition to the temperature measurement unit 21, another temperature measurement unit may be installed outside the chamber 11.

[0018] In the wafer manufacturing apparatus 2, the temperature measurement unit 21, the temperature adjustment unit 23, the heating units 25, 26, 27, 28, etc. are connected to the computer 10, and signals are transmitted between the temperature measurement unit 21, 22, the temperature adjustment unit 23, and the heating units 25, 26, 27, 28. Note that wiring for supplying power to the temperature measurement units 21, 22, the temperature adjustment unit 23, and the heating units 25, 26, 27, 28 is not shown in the drawings.

[0019] The temperature measuring device 1 is equipped with a known computer 10 capable of performing calculations in order to calculate the temperature of the silicon wafer 14, which is the object to be measured, from the detection value of the temperature measuring unit 21. As shown in the block diagram of Figure 2, the computer 10 is equipped with a calculation unit 101 (CPU, GPU, etc.), a ROM 102, a RAM 103, a storage unit 104, etc. in terms of hardware, and is appropriately equipped with an 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, cloud computing systems, etc.

[0020] 1, the computer 10 is also provided with an output display (monitor) 4, an input keyboard 5, and a mouse 6. These are connected to an I / O 105. The temperature measurement unit 21, the temperature adjustment unit 23, and the heating units 25, 26, 27, and 28 disclosed in FIG.

[0021] When each functional unit of the computer 10 of the temperature measuring device 1 is realized by software, the computer 10 executes instructions of a program, which is software that realizes each function. The recording medium that stores this program can be a "non-transitory tangible medium," such as a CD, DVD, semiconductor memory, or programmable logic circuit. The program may also be supplied to the computer 10 of the temperature measuring device 1 via any transmission medium (such as a communication network or broadcast waves) that can transmit the program.

[0022] The storage unit 104 of the computer 10 of the temperature measuring device 1 is provided 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, various data required to execute the programs, and the like.

[0023] The functional units in the calculation unit 101 of the computer 10 of the temperature measurement device 1 are shown in the schematic block diagram of Figure 3. Each functional unit includes a conversion unit 110, a condition acquisition unit 120, a detection value acquisition unit 130, a temperature correction unit 140, and a temperature control unit 150 (a wafer temperature control unit that controls the temperature of the silicon wafer 14, which is the object to be measured) as a configuration for performing temperature control. An output unit that performs processing required for output is also provided. Processing and execution in the temperature measurement device 1 and wafer manufacturing apparatus 2 are realized in software terms by a temperature measurement program loaded into main memory, etc.

[0024] The conversion unit 110 generates conversion data of the temperature change amount of the silicon wafer 14 (measurement object) heated in the chamber 11, which corresponds to the temperature change amount of the chamber window 18, from the actual temperature calculated from the detection value of the temperature measurement unit 21. More specifically, the conversion unit 110 estimates the object temperature change amount of the measurement object from the actual temperature change amount of the actual temperature calculated from the detection value of the temperature measurement unit, excluding the influence of the radiance amount caused by the chamber window. The conversion unit 110 then generates the conversion data from the correlation between the actual temperature change amount and the object temperature change amount.

[0025] The amount of change in the actual temperature calculated from the detected value of the temperature measurement unit 21 (first temperature measurement unit) is a measurement of the so-called apparent temperature change. However, it is obvious that it is difficult to say that it matches the temperature of the silicon wafer 14 in the chamber 11. In particular, since the components of the chamber window 18 are located between the temperature measurement unit 21 and the silicon wafer 14, the influence of radiant heat from the components of the chamber window 18 inevitably occurs. Strictly speaking, there is a discrepancy between the temperature measured in the heated state and the temperature of the silicon wafer 14. The conversion unit 110 generates conversion data to correct (calibrate) this temperature discrepancy.

[0026] The condition acquisition unit 120 acquires heating conditions for the measurement object (silicon wafer 14) in the chamber 11. In this embodiment, the measurement object is a silicon wafer, but epitaxial growth on a substrate made of another material may also be performed. In this case, reference values ​​such as radiance (amount of radiant heat, emissivity) differ for each material. Therefore, the heating conditions acquired include reference values ​​for each material, temperature rise rate (heating rate), and other temperature information for the actual measurement object during epitaxial growth.

[0027] The detection value acquisition unit 130 acquires the detection value of the temperature measurement unit 21. The temperature measurement unit 21 is a temperature measurement device such as a pyrometer, and measures the temperature as the amount of radiance of the target object. The calculation unit 101 of the computer 10 then calculates the temperature of the target from the radiance at the time of measurement.

[0028] The temperature correction unit 140 estimates the temperature of the object to be measured by correcting the actual temperature calculated from the detection value of the temperature measurement unit using the conversion data generated by the conversion unit 110. By correcting the actual temperature change amount of the actual temperature calculated from the detection value of the temperature measurement unit 21 using the conversion data, the influence of the radiance amount caused by the chamber window 18 is eliminated. Therefore, a more accurate temperature of the silicon wafer 14, which is the object to be measured, can be estimated.

[0029] As shown in the schematic diagram of FIG. 4 , when the temperature of the silicon wafer 14, which is the object of measurement, is measured from outside the chamber 11 using a temperature measurement unit 21 such as a pyrometer, the radiance actually measured by the temperature measurement unit 21 includes the radiance of the silicon wafer 14 as well as the radiance due to the chamber window 18 that constitutes the chamber 11, and the detected value is a mixture of both radiances. Here, the chamber window 18 is made of quartz and is a uniform material. It is possible to calculate the radiance due to the quartz chamber window 18 from the heating conditions for the silicon wafer 14, which is the object of measurement. Therefore, the temperature measurement unit 21 first calculates the overall radiance, and then the influence of the radiance due to the quartz chamber window 18 is subsequently eliminated using conversion data, making it possible to finally measure the temperature of the silicon wafer 14, which is the object of measurement.

[0030] Next, we will explain how the conversion data is generated in the conversion unit 110. The conversion data referred to here is data that indicates the correlation between the actual temperature change amount and the target temperature change amount, which is obtained by estimating the target temperature change amount of the silicon wafer 14 from the actual temperature change amount of the actual temperature calculated from the detection value of the temperature measurement unit 21, excluding the influence of the radiance amount caused by the chamber window 18, and is data that can be processed by numerical calculation using a predetermined conversion formula or the like.

[0031] The target temperature change amount refers to the apparent temperature change amount of the silicon wafer 14, which is the measurement target, relative to the temperature change amount of the chamber window 18. For example, it is the apparent temperature rise amount of the measurement target when the temperature of the chamber window 18 rises by 10°C (+10°C) from a certain temperature.

[0032] Currently, the temperature is measured through the chamber window using a temperature measuring device such as a pyrometer, and this measured temperature is considered to be the temperature of the silicon wafer, which is the object to be measured. However, as explained above, when the temperature of the chamber window changes, the apparent temperature of the silicon wafer also changes. Therefore, in controlling the heating temperature of the silicon wafer when epitaxial growth is performed in accordance with the type of gas introduced into the chamber, if the temperature of the chamber window changes over time due to the equipment history, such as repeated temperature increases and decreases, the apparent temperature of the silicon wafer to be controlled changes, resulting in a change in the actual silicon wafer temperature, which may prevent ideal epitaxial growth.

[0033] The graphs in Figure 5 are graphs related to a test in which the operation of the temperature control unit was intentionally varied under control of the temperature measurement unit 21 (first temperature measurement unit) to maintain a constant temperature of the silicon wafer. Figure 5(a) is a graph showing the change in the total output of the heating unit (halogen lamp) when the speed of the temperature control unit is varied in stages (step-like), with the horizontal axis representing time. Figure 5(b) is a graph showing the change in temperature of the chamber window when the speed of the temperature control unit is varied in stages (step-like) over time, with the horizontal axis representing time. The temperature of the chamber window changes depending on the speed of the air blown from the blower.

[0034] 5(c) is a graph showing the relationship between the temperature of the chamber window and the total output of the heating unit (halogen lamp). Under control to maintain the temperature measured through the chamber window constant, a good correlation is observed between the temperature of the chamber window and the output of the heating unit (halogen lamp). In other words, when the temperature of the chamber window is intentionally changed, under control to maintain the temperature of the silicon wafer constant, the apparent temperature of the silicon wafer changes due to the influence of the temperature change at the chamber window, and as a result, the output of the heating unit (halogen lamp) changes.

[0035] The graph related to the operation of the temperature control unit in Figure 5 has the meaning of a preliminary test for determining a correction coefficient. Even if the temperature of the chamber window changes by intentionally changing the speed (i.e., air volume) of the temperature control unit (fan), a coefficient for correcting the temperature change at the chamber window can be determined so that the output remains constant (so that the apparent temperature of the silicon wafer does not change).

[0036] Therefore, the temperature measurement device 1 and wafer manufacturing device 2 of the embodiment have the characteristic of estimating the deviation that inevitably occurs between the temperature change amount of the chamber window portion and the actual temperature change amount of the silicon wafer by calculation using conversion data in advance, and controlling the temperature so that it approaches the ideal heating temperature of the silicon wafer required for epitaxial growth.

[0037] The calculation process in the conversion unit 110 of this embodiment is as follows: ｗ , emissivity ε ｗ The radiance (I ｗ ) is expressed as equation (1), and the temperature T ｄ , emissivity ε ｄ The radiance (I) from the chamber window 18 formed from quartz is ｄ ) is expressed as equation (2). The radiance dependent on the measurement wavelength of the temperature measurement pyrometer is a combination of the following two radiances. In the equation, λ is the monitoring wavelength of the pyrometer (temperature measurement unit 21), which is 3.4 μm. "C1" in the following equations is hc ２ and C2 is hc, where h is Planck's constant and c is the speed of light.

[0038]

[0039]

[0040] The temperature fluctuation (ΔT ｄ ) due to radiance fluctuations (ΔI ｄ ) is expressed as equation (3). From equations (2) and (3), equation (4) is derived.

[0041]

[0042]

[0043] ΔI in Equation (4) ｄ Therefore, the apparent temperature change of the silicon wafer is ΔT ｗ Radiance I by ｗ (T ｗ +ΔT ｗ ) is expressed as Equation (5). ｗ +ΔT ｗ The radiance at this time is expressed as equation (6).

[0044]

[0045]

[0046] ΔT ｄ and ΔT ｗ The relationship can be obtained from equation (7).

[0047]

[0048] Equation (8) and the following equations are transformations of equation (7) that further advance the calculation. Equations (8), (9), and (10) are substitutions that simplify the right-hand side of equation (7). Equation (11) can be transformed in the order of equations (12) to (16) to obtain equation (17).

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059] Finally, from equation (17), the apparent temperature change ΔT of the silicon wafer is ｗ In this way, in the temperature measurement device 1 and wafer manufacturing apparatus 2 of the embodiment, even in a state where temperature measurement is performed using the temperature measurement unit 21 with the chamber window 18 made of quartz interposed therebetween, it is possible to grasp the temperature change of the silicon wafer, which is the object to be measured, while excluding the influence of the radiance of the chamber window 18.

[0060] Calculation of the correlation between the temperature change of the chamber window 18 and the temperature change of the silicon wafer, which is the object to be measured, results in the graph shown in FIG.

[0061] The horizontal axis represents the temperature change (°C) at the chamber window 18, and the vertical axis represents the apparent temperature change (°C) at the silicon wafer 14. The correlation between the two is extremely high (can be approximated as a straight line), and they function as conversion data under the heating conditions.

[0062] Under these heating conditions, the temperature T of the silicon wafer ｗ is 1100°C, and the temperature of the chamber window T ｄ is 550°C, and the emissivity of the silicon wafer ε ｗ is 0.6, and the emissivity of the chamber window ε ｄ is 0.95, A-1 for formula (8) is 20.8, and C-1 for formula (10) is 169.9. Note that similar high correlations are also observed in other demonstrations of the temperature of the silicon wafer and the temperature of the chamber window.

[0063] When correcting the temperature of the silicon wafer based on the temperature of the chamber window, a reference temperature of the quartz chamber window 18 is determined relative to the set temperature of the silicon wafer based on the measurement results of a temperature measurement unit (second temperature measurement unit) 22 installed separately from the temperature measurement unit (first temperature measurement unit) 21. The difference between the actual measurement result of the temperature of the quartz chamber window 18 and the reference temperature of the window is calculated. The temperature of the silicon wafer is then corrected using a coefficient based on linear regression (first-order correlation).

[0064] In actual equipment and materials, the emissivity (ε ｄ , ε ｗ) and variations between chambers and other equipment are unavoidable. Therefore, it is expected that the temperature correction value for the chamber window will fluctuate. Taking this into consideration, the reference temperature for the chamber window is determined based on data from temperature measurements taken during process execution in a reliable number of actual manufacturing stages. Then, the calculated correction value is multiplied by a coefficient for adjustment. The reference temperature for the silicon wafer corresponds to the set temperature to be controlled.

[0065] For temperature correction, a linear correlation (linear regression) conversion formula shown in FIG. 6 is used as an approximation. The linear correlation (linear regression) coefficient is determined so that correction can be performed using a value determined by calculation in advance. In this state, the total output of the heating unit (halogen lamp) is monitored while the temperature of the chamber window is changed by changing the speed (air velocity) of the temperature control unit while controlling the temperature measurement unit 21 (first temperature measurement unit) to maintain a constant silicon wafer temperature. A correction coefficient can be determined so that the total output does not fluctuate. If fluctuations in the total output are observed, the coefficient to be multiplied by the set correction value is adjusted to reduce the fluctuations in the total output, and a coefficient that minimizes the fluctuations in the total output is finally found. Alternatively, a correction coefficient can be determined so that the temperature of the silicon wafer does not change even if the speed (i.e., air volume) of the temperature control unit (blower, fan) is intentionally changed while maintaining a constant output, resulting in a change in the temperature of the chamber window.

[0066] In the graph of FIG. 6, the temperature change (°C) at the chamber window 18 on the horizontal axis is referred to as "ΔT ｗ ", and the temperature change (°C) in the silicon wafer 14 on the vertical axis is "ΔT ｄ ", then from linear regression, "ΔT ｗ = a × ΔT ｄ " where a is a coefficient. a is set so that there is no fluctuation in the total output when the wind speed of the temperature control unit (blower) is changed.

[0067] As explained above, it is now possible to estimate the temperature change of the silicon wafer, which is the object to be measured, by correcting the actual temperature calculated from the detection value of the temperature measurement unit 21 using the converted data. Therefore, in the temperature measurement device 1 of the embodiment, particularly in the wafer manufacturing apparatus 2, the calculation unit 101 is provided with a heating control unit 150. The temperature control unit 150 controls the temperature of the silicon wafer 14, which is the object to be measured and is estimated by the temperature correction unit 140.

[0068] 7, a temperature measurement program in the computer 10 (arithmetic unit 101) of the temperature measurement apparatus 1 and wafer manufacturing apparatus 2 of the embodiment will be described. The temperature measurement method is executed by the arithmetic unit 101 (arithmetic element) of the computer 10 based on the temperature measurement program.

[0069] The temperature measurement program causes the computer 10 in Fig. 2 to execute functions such as conversion, condition acquisition, detection value acquisition, temperature correction, and temperature control. Although not explained here, functions necessary for the device, such as output functions, are also included and executed. Each function overlaps with the explanation of the temperature measurement device 1 described above, so details will be omitted.

[0070] 7, the processing of the calculation unit 101 (calculation element) of the computer 10 includes various steps, such as a conversion step (S110), a condition acquisition step (S120), a detection value acquisition step (S130), a temperature correction step (S140), and a temperature control step (S150). Of course, various steps necessary for the operation of the computer 10 itself are also included.

[0071] The conversion function generates conversion data for the temperature change of the object being heated in the chamber 11 (silicon wafer 14) corresponding to the temperature change of the chamber window 18 from the actual temperature calculated from the value detected by the temperature measurement unit 21 (S110; conversion step). The condition acquisition function acquires the heating conditions for the object being heated in the chamber 11 (silicon wafer 14) (S120; condition acquisition step). The detected value acquisition function acquires the detected value of the temperature measurement unit 21 (S130; detected value acquisition step). The temperature correction function uses the conversion data to correct the actual temperature calculated from the value detected by the temperature measurement unit 21 to estimate the temperature of the object being heated (silicon wafer 14) (S140; temperature correction step). Furthermore, in the case of an apparatus configuration requiring temperature control, a temperature control function is added. The temperature control function controls the output of the heating units 25, 26, 27, and 28 based on the temperature of the object being heated (silicon wafer 14) estimated by the temperature correction unit 140 (S150; temperature control step).

[0072] The computer program of the present invention described above may be recorded on a processor-readable recording medium, and the recording medium may be a "non-transitory tangible medium" such as a disk, card, semiconductor memory, programmable logic circuit, etc.

[0073] The computer program can be implemented using, for example, a scripting language such as ActionScript or JavaScript (registered trademark), an object-oriented programming language such as Objective-C or Java (registered trademark), or a markup language such as HTML5.

[0074] The inventors utilized the temperature measurement device, temperature measurement method, and temperature measurement program disclosed in the above-described embodiments to actually perform epitaxial growth on silicon wafers in a wafer manufacturing apparatus equipped with a temperature measurement device (pyrometer), and measured the temperature, and verified the effectiveness of the temperature measurement device (method, program) of the embodiment.

[0075] 8 and 9 are graphs showing the linear regression ("ΔT" in FIG. 6) based on the values ​​derived from the above-mentioned formula. ｗ = a × ΔT ｄ8 and 9, (a) is a graph showing the temperature measured by the first temperature measuring unit and the speed of the temperature adjustment unit (horizontal axis: time, left vertical axis: temperature (°C), right vertical axis: temperature (K)). Also, in FIGS. 8 and 9, (b) is a graph showing the temperature measured by the first temperature measuring unit and the temperature measured by the second temperature measuring unit (horizontal axis: time, left vertical axis: temperature (°C), right vertical axis: temperature (°C)).

[0076] As shown in Figure 8(a), as the speed of the temperature control unit (blower) gradually decreases, the measured temperature (so-called apparent temperature) of the first temperature measurement unit (for measuring silicon wafers) without coefficient correction increases. In other words, as the movement of the temperature control unit (blower) weakens (as the air volume decreases), the air-cooling effect decreases, resulting in a rise in temperature. As shown in Figure 8(b), the measured temperature of the first temperature measurement unit (for measuring silicon wafers) corresponds to the temperature change of the chamber window (quartz dome) that changes with the speed of the temperature control unit. Similar graphs also show changes in Figures 9(a) and 9(b).

[0077] Here, Figure 8 shows the results when the coefficient was adjusted to 0.2. The areas enclosed by dashed lines in Figures 8(a) and (b) represent the temperature values ​​at the time when correction was attempted for the pyrometer measurement value of the first temperature measurement unit (for measuring the silicon wafer). In Figure 8(a), the temperature values ​​were almost constant at each correction time, independent of the speed of the temperature control unit (blower). In Figure 8(b), the temperature values ​​were almost constant at each correction time, unaffected by changes in the temperature values ​​of the second temperature measurement unit (for measuring the chamber window) (for measuring the quartz dome).

[0078] Compared to the situation in Figure 8, Figure 9 shows the results when the coefficient was adjusted to 0.1. The areas enclosed by dashed lines in Figures 9(a) and (b) represent the temperature values ​​at the time when correction was attempted for the pyrometer measurement value of the first temperature measurement unit (for measuring the silicon wafer). In Figure 9(a), the chamber temperature changes (temperature increases) in conjunction with the speed (speed decrease) of the temperature control unit (blower). Therefore, the temperature values ​​at each correction time point increased in conjunction with the chamber temperature. In Figure 9(b), the temperature values ​​at each correction time point increased due to the influence of the temperature change (temperature increase) of the second temperature measurement unit (for measuring the chamber window) (for measuring the quartz dome). The coefficient value conditions in Figure 9 do not completely eliminate the influence of temperature changes in the chamber (quartz dome) on the temperature measurement of the silicon wafer inside it.

[0079] Therefore, from a comparison of the graphs in Figures 8 and 9, when the temperature of the silicon wafer heated inside the chamber (quartz dome) is measured using the pyrometer of the first temperature measurement unit (for measuring the silicon wafer), by selecting an appropriate coefficient value, it is possible to reduce the influence of the temperature value of the chamber (quartz dome), etc., and calculate a more accurate temperature value.

[0080] In the graph of Figure 10, the upper part shows the time series changes in the temperature measurement values ​​by the pyrometer of the first temperature measurement unit (for measuring silicon wafers) and the temperature measurement values ​​by the second temperature measurement unit (for measuring the chamber window) (for measuring the quartz dome). The lower part shows the time series changes in the temperature measurement values ​​by the pyrometer of the first temperature measurement unit (for measuring silicon wafers) and the output value (kW) of the heating unit. Here, the left side of the figure shows the graph waveform when the above-mentioned correction function is activated for the first temperature measurement unit (for measuring silicon wafers), and the part from the center to the right side of the figure shows the graph waveform when the above-mentioned correction function is deactivated for the same first temperature measurement unit (for measuring silicon wafers).

[0081] In an actual silicon wafer epitaxial growth process, the temperature of the chamber (quartz dome) changes as the process temperature rises and falls. When the correction function is disabled (not activated), the heating output decreases as the temperature of the chamber (quartz dome) changes, even after the silicon wafer temperature stabilizes (see the diagonal dashed line on the right side of the bottom row). This phenomenon occurs when the temperature of the chamber (quartz dome) rises, causing the temperature measured by the radiation thermometer (pyrometer) measuring the silicon wafer to appear higher than the actual temperature of the silicon wafer. This causes the output of the heating unit to decrease in response to the apparent increase in the temperature of the silicon wafer. This creates a problem in that the amount of heat applied to the silicon wafer decreases, even though the output of the heating unit actually needs to be maintained or increased.

[0082] To address this issue, a correction function is activated for the temperature measurement value of the first temperature measurement unit (for measuring the silicon wafer) while taking into account the temperature measurement value of the second temperature measurement unit (for measuring the chamber window) (for measuring the quartz dome), thereby reducing the impact of temperature changes in the chamber (quartz dome) and making it possible to accurately estimate and perform the necessary heating only on the silicon wafer inside. This is clear from the fact that the heating output is kept constant while the correction function is activated, as shown by the dashed line on the left side of the bottom row in Figure 10.

[0083] REFERENCE SIGNS LIST 1 Temperature measurement device 2 Wafer manufacturing device 4 Display (monitor) 10 Computer 11 Chamber 12 Lower chamber 13 Susceptor 14 Silicon wafer 18 Chamber window 21 Temperature measurement section (first temperature measurement section) 22 Temperature measurement section (second temperature measurement section) 23 Temperature adjustment section 25, 26, 27, 28 Heating section 101 Calculation section 102 ROM 103 RAM 104 Storage section 105 I / O 110 Conversion section 120 Condition acquisition section 130 Detection value acquisition section 140 Temperature correction section 150 Temperature control section

Claims

1. An epitaxial growth apparatus chamber for housing an object to be measured therein, a heating unit for heating the object to be measured, a chamber window provided at a position of the chamber facing the object to be measured, a temperature measurement unit installed outside the chamber window of the epitaxial growth apparatus for measuring the temperature of the object to be measured and the temperature of the chamber window through the chamber window, and a calculation unit for calculating the temperature of the object to be measured from a detection value of the temperature measurement unit, wherein the calculation unit includes a conversion unit for generating conversion data corresponding to a temperature change amount of the object to be measured heated in the chamber, which corresponds to a temperature change amount of the chamber window, from an actually measured temperature calculated from the detection value of the temperature measurement unit, a condition acquisition unit for acquiring heating conditions for the object to be measured in the chamber, a detection value acquisition unit for acquiring the detection value of the temperature measurement unit, and a temperature correction unit for correcting the actually measured temperature calculated from the detection value of the temperature measurement unit using the conversion data to estimate the temperature of the object to be measured. The temperature measurement device is characterized by comprising the above components.

2. The conversion unit according to claim 1, wherein the conversion unit estimates a target temperature change amount of the object to be measured by excluding the influence of the radiant luminance amount caused by the chamber window from the actually measured temperature change amount of the actually measured temperature calculated from the detection value of the temperature measurement unit, and generates the conversion data from the correlation relationship between the actually measured temperature change amount and the target temperature change amount.

3. The heating unit is provided outside the chamber, and the calculation unit according to claim 1 includes a temperature control unit for controlling the output of the heating unit based on the temperature of the object to be measured estimated by the temperature correction unit.

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

5. The temperature measurement device according to claim 1, wherein the chamber window is made of quartz.

6. The temperature measurement device according to claim 1, wherein a temperature control unit for cooling the chamber is provided outside the chamber.

7. A temperature measurement method in a temperature measurement device including a chamber of an epitaxial growth apparatus that houses an object to be measured therein, a heating unit that heats the object to be measured, a chamber window portion provided at a position of the chamber facing the object to be measured, a temperature measurement unit that is installed outside the chamber window portion of the epitaxial growth apparatus and measures the temperature of the object to be measured and the temperature of the chamber window portion through the chamber window portion, and an arithmetic unit that calculates the temperature of the object to be measured from a detection value of the temperature measurement unit, wherein the arithmetic unit performs: a conversion step of generating conversion data corresponding to a temperature change amount of the chamber window portion from an actually measured temperature calculated from a detection value of the temperature measurement unit, the conversion data being for a temperature change amount of the object to be measured heated in the chamber; a condition acquisition step of acquiring heating conditions for the object to be measured in the chamber; a detection value acquisition step of acquiring a detection value of the temperature measurement unit; and a temperature correction step of correcting the actually measured temperature calculated from the detection value of the temperature measurement unit using the conversion data and estimating the temperature of the object to be measured.

8. A temperature measurement program in a temperature measurement device including a chamber of an epitaxial growth apparatus that houses an object to be measured therein, a heating unit that heats the object to be measured, a chamber window portion provided at a position of the chamber facing the object to be measured, a temperature measurement unit that is installed outside the chamber window portion of the epitaxial growth apparatus and measures the temperature of the object to be measured and the temperature of the chamber window portion through the chamber window portion, and an arithmetic unit that calculates the temperature of the object to be measured from a detection value of the temperature measurement unit, wherein the arithmetic unit realizes: a conversion function of generating conversion data corresponding to a temperature change amount of the chamber window portion from an actually measured temperature calculated from a detection value of the temperature measurement unit, the conversion data being for a temperature change amount of the object to be measured heated in the chamber; a condition acquisition function of acquiring heating conditions for the object to be measured in the chamber; a detection value acquisition function of acquiring a detection value of the temperature measurement unit; and a temperature correction function of correcting the actually measured temperature calculated from the detection value of the temperature measurement unit using the conversion data and estimating the temperature of the object to be measured.

9. An epitaxial growth apparatus including a chamber for accommodating a silicon wafer therein, a heating unit for heating the silicon wafer, a chamber window portion made of quartz provided at a position of the chamber facing the silicon wafer, a temperature measurement unit installed outside the chamber window portion of the epitaxial growth apparatus for measuring the temperature of the object to be measured through the chamber window portion and the temperature of the chamber window portion, and an arithmetic unit for calculating the temperature of the silicon wafer from the detection value of the temperature measurement unit, wherein the arithmetic unit includes a conversion unit for generating conversion data of a temperature change amount of the silicon wafer heated in the chamber corresponding to a temperature change amount of the chamber window portion from the actually measured temperature calculated from the detection value of the temperature measurement unit, a condition acquisition unit for acquiring heating conditions for the silicon wafer in the chamber, a detection value acquisition unit for acquiring the detection value of the temperature measurement unit, and a temperature correction unit for correcting the actually measured temperature calculated from the detection value of the temperature measurement unit using the conversion data to estimate the temperature of the silicon wafer. A wafer manufacturing apparatus characterized by the above.

10. The heating unit is provided outside the chamber, and the arithmetic unit includes a temperature control unit for controlling the output of the heating unit based on the temperature of the object to be measured estimated by the temperature correction unit. The wafer manufacturing apparatus according to claim 9.

11. The wafer manufacturing apparatus according to claim 9, further including a temperature control unit for cooling the chamber outside the chamber.

12. The temperature control unit according to claim 10 performs feedback control. The wafer manufacturing apparatus according to claim 10.

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