JP2017017251A - Vapor phase growth device and temperature detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly precisely detect temperatures at a film growth surface on a substrate.SOLUTION: A vapor phase growth device includes: a reaction chamber where a vapor phase growth reaction is caused to a substrate; a gas supply section for supplying gas into the reaction chamber; a heating means for heating the substrate; and a radiation thermometer disposed above a film growth surface of the substrate to measure temperatures of the film growth surface. The radiation thermometer includes a calculation section for correcting at least one of a phase of a heat radiation light intensity and a phase of a reflectance so that a phase of the heat radiation light intensity and a phase of the reflectance match to each other, and determining a temperature at the film growth surface on the basis of the heat radiation light intensity and the reflectance which have phases having been matched.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a vapor phase growth apparatus and a temperature detection method.

  The radiation thermometer measures the temperature of the measurement object by measuring the intensity of heat radiation emitted from the measurement object. A radiation thermometer can measure the temperature of an object to be measured in a non-contact manner, so it can be used for the purpose of film formation while monitoring the growth temperature of each film in the film formation process for forming multiple films on a substrate. it can.

  By the way, in general, the heat radiation intensity from the measurement object is smaller than the heat radiation intensity from the black body at the same temperature. The emissivity is obtained by dividing the heat radiation intensity from an object at a certain temperature by the heat radiation intensity from a black body at the same temperature. This is expressed by equation (1).

P (T, ε) = ε × Pb (T) (1)

  Here, ε is the emissivity of the measurement object, P is the thermal radiation intensity at the temperature T, and Pb is the thermal radiation intensity from the black body at the temperature T. Therefore, by measuring the thermal radiation intensity from the measurement object, dividing this thermal radiation intensity by the emissivity of the object, and correcting the effect of the emissivity, a black body at the same temperature as this object emits. The heat radiation intensity can be obtained, and the temperature of the object can be calculated from the heat radiation intensity.

  For this reason, in order to measure temperature accurately using a radiation thermometer, the exact emissivity value of a measurement object is required. However, since the emissivity depends not only on the material of the measurement object but also on the surface state and temperature, it is not easy to accurately obtain an appropriate emissivity value of the measurement object.

  On the other hand, under certain limited conditions, it is possible to measure emissivity. In other words, in the wavelength range of the light for measuring the heat radiation light intensity, if the light does not pass through the object to be measured and the light irradiated on the surface of the object to be measured is not scattered, the light is reflected on the surface of the object to be measured. When the rate is R, the emissivity (ε) is expressed by equation (2).

ε = 1−R (2)

  Therefore, in the wavelength range of the light for measuring the heat radiation intensity, the surface of the measurement object has sufficient specularity, and the reflectance of the measurement object can be measured using an external light source. When the measurement object absorbs light (light transmittance is 0), the emissivity can be obtained regardless of the surface state and temperature of the measurement object.

JP 2000-105152 A

  When a thin film is formed on the substrate, multiple reflection occurs between the surface of the thin film and the surface of the substrate, so that the reflectance periodically changes depending on the film thickness of the thin film. The period of the film thickness at which the reflectance changes depends on the refractive index of the thin film to be formed and the wavelength used for measurement. Specifically, when the refractive index of the thin film to be formed is n, the wavelength used for measurement is λ, and the period of the film thickness at which the reflectance changes is dp, it is expressed by equation (3).

dp = λ / 2n (3)

Alternatively, let d be the thickness of the thin film, and the reflectance is as in equation (4):
φ = 4πnd / λ (4)
It can be seen that the phase changes.

  The thermal radiation intensity from the measurement object depends on the emissivity of the measurement object, and this emissivity has a relationship with the reflectance in the formula (2), so in principle, the thermal radiation intensity and the reflectance The phase with respect to the change in film thickness should match, but in practice, the phase of the emissivity obtained by measuring the reflectance and the change in film thickness of the thermal radiation intensity is completely matched. difficult. For example, the spectrum of a light source used for measuring reflectance is generally different from the spectrum of thermal radiation. For this reason, even if the same wavelength selection filter is used for the measurement of the reflectance and the heat radiation light intensity, the wavelength width of the light passing through the wavelength selection filter is finite, so the period of the film thickness at which the reflectance changes The period of the film thickness at which the emissivity changes is slightly different. This can be said that the apparent wavelength defined by the equation (4) is different in reflectance and emissivity. From equation (4), when the phase of emissivity φe and the phase of reflectivity are φr, the difference δφ uses the apparent wavelength λr found in the measurement of reflectivity and λe found in the measurement of thermal radiation intensity. Is expressed by the following equation (5).

  δφ = 4πnd (1 / λe−1 / λr) (5)

  As can be seen from equation (5), the phase of the periodic change with respect to the film thickness of the reflectance and emissivity increases as the film thickness increases. That is, as the film thickness increases, the emissivity obtained from the reflectance gradually deviates from the actual emissivity. That is, the error obtained by correcting the temperature using the emissivity obtained from the reflectance increases as the thickness of the thin film increases.

  When the growing thin film absorbs light of the wavelength used for the radiation thermometer measurement, the periodic oscillation of the reflectance with respect to the film thickness decreases as the film thickness increases, and finally becomes a constant value. . This is because light is absorbed inside the thin film to be formed, so that almost no light is reflected from the lower surface of the thin film. In such a case, fluctuations in the reflectance and thermal radiation light intensity with respect to the film thickness gradually disappear as the film thickness increases, so that the temperature error as described above does not become a significant problem. On the other hand, when the growing thin film does not absorb light in the wavelength region used for the measurement of the radiation thermometer, the variation of the reflectance with respect to the film thickness does not disappear, so the temperature error as described above can be a big problem.

  The present invention has been made in view of the above-described problems, and provides a vapor phase growth apparatus and a temperature detection method capable of accurately detecting the temperature of a film growth surface on a substrate.

  The vapor phase growth apparatus according to the present embodiment includes a reaction chamber that causes a vapor phase growth reaction on the substrate, a gas supply unit that supplies gas to the reaction chamber, and a surface side opposite to the film growth surface of the substrate. And heating means for heating the substrate, and a radiation thermometer disposed above the film growth surface of the substrate and measuring the temperature of the film growth surface, the radiation thermometer comprising: At least one of the phase of the thermal radiation light intensity and the phase of the reflectance is corrected so that the phase of the heat radiation light intensity and the phase of the reflectance of the film growth surface are matched, and the phase is matched by the correction. A calculation unit for obtaining a temperature of the film growth surface based on the heat radiation intensity and the reflectance;

  In the vapor phase growth method according to the present embodiment, the source gas is supplied to the substrate while heating the substrate by a heating unit, and a single film or a plurality of films are sequentially grown on the substrate. A temperature detection method for detecting temperature, wherein a radiation thermometer is disposed above a film growth surface of the substrate, and the heat radiation intensity and reflected light intensity from the substrate are measured, and the heat radiation intensity of the substrate is measured. Correcting at least one of the phase of the thermal radiation intensity and the phase of the reflectance so that the phase and the phase of the reflectance are matched, and the thermal radiation intensity and the reflectance matched in phase by the correction Based on the above, the temperature of the film growth surface is obtained.

The figure which shows schematic structure of the vapor phase growth apparatus by one Embodiment. The figure which shows the internal structure of a radiation thermometer. The flowchart which shows an example of the process sequence of the calculation part in a radiation thermometer. The wave form diagram of heat radiation light intensity. The figure which shows an example of the curve showing a thermal radiation light intensity | strength and a reflectance. The figure which shows the curve which shows the time change of the temperature measured with the radiation thermometer when not performing with the process of FIG.

  FIG. 1 is a diagram showing a schematic configuration of a vapor phase growth apparatus 1 according to an embodiment. In the present embodiment, an example will be described in which a silicon substrate, specifically, a silicon wafer (hereinafter simply referred to as a wafer) W is used as a substrate for film formation, and a plurality of films are stacked on the wafer W.

  A vapor phase growth apparatus 1 in FIG. 1 includes a chamber 2 for forming a film on a wafer W, a gas supply unit 3 for supplying a source gas to the wafer W in the chamber 2, and a source discharge unit located above the chamber 2. 4, a susceptor 5 that supports the wafer W in the chamber 2, a rotating unit 6 that rotates while holding the susceptor 5, a heater 7 that heats the wafer W, and a gas discharge unit that discharges the gas in the chamber 2. 8, an exhaust mechanism 9 that exhausts gas from the gas exhaust unit 8, a radiation thermometer 10 that measures the temperature of the wafer W, and a control unit 11 that controls each unit.

  The chamber 2 has a shape (for example, a cylindrical shape) that can accommodate the wafer W to be formed, and the susceptor 5, the heater 7, a part of the rotating unit 6, and the like are accommodated in the chamber 2.

  The gas supply unit 3 includes a plurality of gas storage units 3a that individually store a plurality of gases, a plurality of gas pipes 3b that connect the gas storage units 3a and the material discharge unit 4, and a gas that flows through the gas pipes 3b. And a plurality of gas valves 3c for adjusting the flow rate of the gas. Each gas valve 3c is connected to a corresponding gas pipe 3b. The plurality of gas valves 3 c are controlled by the control unit 11. The actual piping can take a plurality of configurations such as coupling a plurality of gas pipes, branching one gas pipe into a plurality of gas pipes, or combining the branching and coupling of gas pipes.

  The source gas supplied from the gas supply unit 3 is released into the chamber 2 through the source release unit 4. The source gas (process gas) released into the chamber 2 is supplied onto the wafer W, whereby a desired film is formed on the wafer W. In addition, the kind of source gas to be used is not specifically limited.

  A shower plate 4 a is provided on the bottom surface side of the raw material discharge portion 4. The shower plate 4a can be configured using a metal material such as stainless steel or an aluminum alloy. Gases from the plurality of gas pipes 3b are mixed in the raw material discharge section 4 and supplied into the chamber 2 through the gas outlet 4b of the shower plate 4a. Note that a plurality of gas flow paths may be provided in the shower plate 4a, and a plurality of types of gases may be supplied to the wafer W in the chamber 2 while being separated.

  The structure of the raw material discharge portion 4 should be selected in consideration of the uniformity of the formed film, the raw material efficiency, the reproducibility, the manufacturing cost, etc., but is not particularly limited as long as these requirements are satisfied. The thing of a well-known structure can also be used suitably.

  The susceptor 5 is provided on the upper portion of the rotating unit 6 and has a structure in which the wafer W is placed and supported in a counterbore 5 a provided on the inner peripheral side of the susceptor 5. In the example of FIG. 1, the susceptor 5 has an annular shape having an opening at the center thereof, but may have a substantially flat plate shape without an opening.

  The heater 7 is a heating unit that heats the susceptor 5 and / or the wafer W. There is no particular limitation as long as it satisfies requirements such as the ability to heat the object to be heated to a desired temperature and temperature distribution, and durability. Specific examples include resistance heating, lamp heating, and induction heating.

  The exhaust mechanism 9 exhausts the reacted raw material gas from the inside of the chamber 2 through the gas exhaust unit 8, and controls the inside of the chamber 2 to a desired pressure by the action of the exhaust valve 9b and the vacuum pump 9c.

  The radiation thermometer 10 is provided on the upper surface of the raw material discharge unit 4. The radiation thermometer 10 irradiates the wafer W with light from the light source, receives reflected light from the wafer W, and measures the reflected light intensity of the wafer W. The radiation thermometer 10 receives heat radiation from the film growth surface Wa of the wafer W, and measures the heat radiation intensity. The radiation thermometer 10 has a calculation unit 10g therein. The calculation unit 10g corrects the phase of the heat radiation light intensity or the phase of the reflectance so that the phase of the heat radiation light intensity of the film growth surface Wa of the wafer W matches the phase of the reflectance, and the phase is adjusted by the correction. The temperature of the film growth surface is obtained based on the obtained heat radiation light intensity and reflectance. The calculation unit 10g can be configured by a general-purpose computer, for example.

  A light transmission window 2a is provided on the upper surface of the raw material discharge portion 4, and light from the light source of the radiation thermometer 10, reflected light from the wafer W, and heat radiation light pass through the light transmission window 2a. . The light transmission window 2a can take an arbitrary shape such as a slit shape, a rectangular shape, or a circular shape. For the window 2a, a transparent member is used in the wavelength range of light measured by the radiation thermometer 10 of the present embodiment. When measuring a temperature from room temperature to about 1500 ° C., it is preferable to measure the wavelength of light from the visible region to the near-infrared region, in which case quartz or the like is suitably used as the member of the window 2a.

  The control unit 11 includes a computer that intensively controls each unit in the vapor phase growth apparatus 1 and a storage unit that stores film formation process information and various programs related to the film formation process. The control unit 11 controls the rotation mechanism, the exhaust mechanism 9 and the like of the gas supply unit 3 and the rotation unit 6 based on the film forming process information and various programs, and controls the heating of the wafer W by the heater 7.

  FIG. 2 is a diagram showing an internal configuration of the radiation thermometer 10. The radiation thermometer 10 includes a light source 10a, a half mirror 10b, a focus adjustment lens 10c, a wavelength selection filter 10d, a diaphragm 10e, a light receiving unit 10f, and a calculation unit 10g.

  The light source 10a emits illumination light L1 for irradiating the wafer W. The half mirror 10b reflects the illumination light L1 toward the wafer W and transmits the light from the wafer W. The lens 10c forms an image on the wafer W with the illumination light L1 transmitted through the half mirror 10b. The lens 10c forms an image of the reflected light L1a from the wafer W and the heat radiation light L2 on the light receiving surface M1 of the light receiving unit 10f. The wavelength selection filter 10d transmits the reflected light L1a and the heat radiation light L2 in a predetermined wavelength range out of the light transmitted through the half mirror 10b. The diaphragm 10e transmits only light from a portion necessary for measurement on the wafer W. The light receiving unit 10f receives the reflected light L1a and the heat radiation light L2 that have passed through the diaphragm 10e. The calculation unit 10g obtains the temperature of the wafer W based on the intensity of the reflected light L1a (reflected light intensity) received by the light receiving unit 10f and the intensity of the heat radiation light L2 (heat radiation light intensity). In other words, the calculation unit 10g detects the temperature of the film growth surface in a state where the thermal radiation light intensity and the reflectance of the film growth surface Wa on the wafer W are matched.

  The light receiving unit 10f simultaneously detects thermal radiation light and reflected light of the light irradiated on the wafer W from the light source 10a. By intermittently turning on and off the light of the light source 10a, the light receiving unit 10f repeats similarly the case of receiving both the heat radiation light and the reflected light and the case of receiving only the heat radiation light. The intensity of the reflected light can be obtained from the difference in signal from the light receiving unit in these two cases.

  As a wavelength range used for the measurement with the radiation thermometer 10 according to the present embodiment, 800 nm to 1500 nm can be mentioned. Wavelengths in this range are suitable for measuring temperatures of about 500 ° C. to 1500 ° C., and are important because the growth temperature of gallium nitride based semiconductors that have recently been recognized as important are within this range. A light emitting diode is preferably used as the light source 10a for measuring the reflectance. This is because a light-emitting diode is a stable light source, and many light sources can be used in the above-described wavelength range, and thus have high durability. The width of the wavelength range of the wavelength selection filter 10d is 50 nm or less. When the width of the wavelength range of the wavelength selective filter 10d is larger than 50 nm, the difference between the spectrum of the light source for measuring the reflectance and the thermal radiation spectrum becomes large, and it cannot be suitably used. In order to reduce the difference between the spectrum of the light source for measuring the reflectance and the thermal radiation spectrum, it is preferable that the width of the wavelength range of the wavelength selection filter 10d is small. In that respect, the more preferable wavelength range of the wavelength selective filter 10d is 20 nm, and more preferably 10 nm or less. However, if the width of the above wavelength range is smaller than 10 nm, the amount of received light is reduced, which is not preferable because the measurement accuracy is lowered.

  As shown in FIG. 2, the calculation unit 10g in the radiation thermometer 10 includes a phase detection unit 10h, a reflectance detection unit 10i, a fitting unit 10j, and a temperature calculation unit 10k. The phase detection unit 10 h detects the current phase from the temporal change of the heat radiation light intensity measured by the radiation thermometer 10. The reflectance detector 10 i detects the maximum value and the minimum value of the reflectance of the film growth surface Wa of the wafer W based on the reflected light intensity measured by the radiation thermometer 10. The fitting 10j adjusts the phase of the modeled reflectance function based on the phase detected by the phase detector 10h, and the maximum and minimum values of the reflectance detected by the reflectance detector 10i. Based on the above, the fitting parameter of the reflectance function is adjusted. The temperature calculation unit 10k calculates the temperature based on the reflectance function adjusted by the fitting unit 10j and the heat radiation light intensity. These may be configured by software.

  FIG. 3 is a flowchart showing an example of a processing procedure of the calculation unit 10 g in the radiation thermometer 10. First, a modeled reflectance function is prepared (step S1). The reflectance function can be approximated most simply by a sine function. As a more accurate approximation, for example, the reflectance function can be expressed by the following equation (6).

  A · (sin (φ) +1) · (1-α (sin (φ) +1)) + B (6)

  The function of the reflectance exemplified here is a case where the thin film does not absorb light of the wavelength used by the radiation thermometer 10 for measurement. When the thin film absorbs light having a wavelength used for measurement, it can be expressed by multiplying the term of the equation (6) by an exponential function with respect to the increase of the film thickness. Hereinafter, only the case where the thin film does not absorb the light of the wavelength used for the measurement will be described. However, in the case where this is not the case, if the equation (6) is expressed as described above so that the amplitude of the reflectance is attenuated, the same as in this embodiment It is applicable to.

  The constant α in the equation (6) is a preset value (for example, 0.2). φ is a phase corresponding to the periodic change of the reflectance with respect to the film thickness. φ is proportional to the thickness of the thin film to be formed. Further, if the thin film formation rate is constant regardless of time, φ is proportional to the thin film formation time. A and B are parameters that can be calculated from the maximum and minimum values of the measured reflectance. That is, two parameters A and B are calculated from the minimum value and the maximum value of the reflectivity, and if the current phase (φ) is known, the current reflectivity can be calculated by equation (6). In Equation (6), A and B are fitting parameters that are fitted in step S5 described later. As an example, A and B may be fitted using the maximum and minimum values of the most recent set of reflectivity from the time when the reflectivity and thermal radiation intensity are actually measured.

  In addition, the specific formula of the reflectance function prepared in step S1 is not limited to the formula (6). As described above, it may be a simple sine function or a more complicated expression than the expression (6).

  Next, the phase detection unit 10h obtains the current phase of the heat radiation light intensity from the temporal change of the heat radiation light intensity measured by the radiation thermometer 10 (step S2). A simple method of this step S2 is to obtain the current phase from the time of the two latest maximum values (or minimum values) of the heat radiation light intensity and the interval therebetween. For example, when the measured value of the heat radiation light intensity is represented by a graph as shown in FIG. 4, when the times T1 and T2 of the maximum value of this graph are detected, the phase of the current time T3 is expressed by the following equation (7). Can be represented.

  (T3-T2) / (T2-T1) × 2π (7)

  When the current phase is obtained using equation (7), the phase is calculated using the same T1 and T2 until a new maximum value of the heat radiation light intensity is obtained. If the deposition rate of the thin film formed during that time changes, an accurate phase cannot be obtained. Therefore, phase adjustment with the reflectance function prepared in step S1 may be performed in real time in accordance with the current time and amplitude value of the heat radiation light intensity. In addition, if one maximum value and one minimum value of reflectance are used in the most recent time, a time difference corresponding to half of the above method can be obtained. The phase of the heat radiation intensity can be obtained.

  Next, the reflectance is obtained from the reflected light intensity measured by the radiation thermometer 10 (step S3). Here, the reflected light intensity Iref of a substance having a known reflectance Rref is measured in advance. For example, in the case of the silicon wafer W, the reflectance is about 30%. When the reflected light intensity Imes measured by the radiation thermometer 10 is used, the reflectance Rmes can be obtained by the following equation (8).

  Rmes = Imes / Iref · Rref (8)

  Next, the reflectance detection unit 10i obtains the nearest maximum value and minimum value of the reflectance using the reflectance obtained in step S3 (step S4). Here, for example, a reflectance curve having the horizontal axis as time and the vertical axis as reflectance is generated using the reflectance obtained in step S3, and the nearest maximum value and minimum value of the reflectance are generated using this curve. May be detected.

  Next, the fitting unit 10j uses the phase of the thermal radiation light obtained in step S2 and the maximum and minimum values of the reflectance obtained in step S4 to model the reflectance function prepared in step S1. Thus, the reflectance according to the current phase of the measured heat radiation light intensity is calculated (step S5).

  Thus, in step S5, when the modeled reflectance function is expressed by, for example, equation (6), based on the latest maximum value and minimum value of the reflectance obtained in step S4, (6) The parameters A and B in the equation are determined (that is, A and B are fitted), and the reflectance is corrected using the phase (6) φ of the heat radiation light intensity obtained in step S2. Thereby, the reflectance is corrected so that the phases of the heat radiation light intensity are aligned.

  Next, the temperature calculation unit 10k obtains the temperature of the film growth surface of the wafer W using the heat radiation light intensity and the reflectance with the same phase (step S6).

  In step S6, for example, the temperature can be obtained by the following procedure. Planck's radiation law is expressed by the following equation (9). The unit of temperature is absolute temperature.

  In Equation (9), L is the thermal radiation intensity, c1 is the Planck first constant, c2 is the Planck second constant, T is the temperature, λ is the measurement wavelength, and ε is the emissivity. The denominator “−1” on the right side of equation (9) is ignored in the normal temperature range.

  Therefore, the temperature T in the equation (9) can be expressed by the following equation (10).

  Actually, the thermal radiant intensity L0 at a temperature T0 with a black body having an emissivity ε = 1 is measured, and the temperature Tunc assumed that the measurement object is a black body is the following using the thermal radiation temperature L0 of the measurement object: (11).

  Further, the temperature Tcor corrected using the emissivity ε obtained from the measured reflectance can be calculated by the following equation (12).

  FIG. 5 is an example of a curve representing the heat radiation light intensity and the reflectance. In FIG. 5, the horizontal axis represents time, and the vertical axis represents thermal radiation intensity or reflectance. A curve w1 in FIG. 5 is an actual measurement curve of thermal radiation light intensity, a curve w2 is an actual measurement curve of reflectance, and a curve w3 is a curve of a reflectance function in which the phase is aligned with the phase of thermal radiation light intensity.

  As shown by the curves w1 and w2 in FIG. 5, when the phase of the thermal radiation light intensity measured by the radiation thermometer 10 and the reflectance are shifted, the process of FIG. 3 is performed to correct the phase of the reflectance function. The phase of the curve w3 and the curve w1 of the heat radiation light intensity can be made uniform. If the phase of the reflectance and the heat radiation light intensity match, the temperature of the film growth surface of the wafer W can be obtained with high accuracy using the above-described equations (11) and (12).

  FIG. 6 is a curve showing temporal changes in temperature measured by the radiation thermometer 10 when the process of FIG. 3 is performed and when it is not performed. The horizontal axis in FIG. 6 is time (seconds), and the vertical axis is temperature (° C.). A curve w4 in FIG. 6 indicates a temperature when the process of FIG. 3 is performed, and a curve w5 indicates a temperature when the process of FIG. 3 is not performed.

  As can be seen by comparing the curves w4 and w5 in FIG. 6, by performing the process in FIG. 3, temperature fluctuations can be suppressed, and temperature errors can be suppressed within about 3 ° C. This is considered to be because the phases of the thermal radiation light intensity and the reflectance are aligned. When the phases are shifted, the temperature error is about 5 ° C. as shown by the curve w5.

  As described above, in the present embodiment, the fitting parameter of the reflectance function is adjusted based on the latest maximum and minimum values of the reflectance actually measured, and the thermal radiation intensity measured by the radiation thermometer 10 is further adjusted. The phase of the reflectance function is corrected so as to match the phase. In this manner, the temperature of the film growth surface of the wafer W can be measured in a state where the phases of the heat radiation light intensity and the reflectance are aligned. Therefore, the temperature measurement accuracy can be improved. In the vapor phase growth apparatus 1 according to the present embodiment, the temperature of the heater 7 can be adjusted based on the temperature measurement result. Therefore, if the temperature measurement accuracy is improved, the temperature at which the film is formed on the wafer W is strictly controlled. Can be set. Therefore, the quality of the film formed on the wafer W can be improved.

  In the above-described embodiment, the example of correcting the phase of the reflectance function so as to match the phase of the thermal radiation light intensity has been described. Conversely, a function modeling the thermal radiation light intensity is provided, and the phase of the reflectance is provided. The phase of the model function of the heat radiation light intensity may be corrected so as to meet. In this case, the calculation unit in the radiation thermometer 10 detects the temperature of the film growth surface Wa in a state where the phase of the thermal radiation light intensity is matched with the phase of the reflectance of the film growth surface Wa of the wafer W. . Further, both phases may be corrected so that both phases are matched by applying a modeled function to both the reflectance and the heat radiation light intensity.

  The example of the reactor shown in FIG. 1 is a single-wafer type that processes a single substrate, but the present invention is similarly applied to a multi-sheet furnace in which a large number of substrates are placed on a susceptor to form a film. The form is applicable. Moreover, although this embodiment demonstrated the method of supplying source gas to the heated board | substrate, it can apply also to a vapor deposition method, a molecular beam epitaxy method, sputtering method, etc. in addition to this.

  In the embodiments described so far, the example in which the silicon wafer W is used as the substrate has been described. However, silicon absorbs light in the visible and near infrared wavelength regions. For this reason, when light in the visible region to the near infrared region is used for measurement in this embodiment, the emissivity can be obtained from the reflectance. On the other hand, substrates that are transparent in the visible to infrared wavelength range, such as sapphire, are often used as substrates for thin film deposition. In this case, strictly speaking, the emissivity cannot be determined only from the reflectance, and this embodiment cannot be used. However, even in that case, when the transparent substrate is placed on the susceptor 5 that is opaque in the target wavelength region such as graphite, and the radiation thermometer 10 measures the heat radiation from the susceptor 5 through the transparent substrate, the susceptor 5 is The present embodiment can be applied by treating it as a temperature measurement target. In that case, it is necessary to pay attention to the multiple reflection between the surface of the transparent substrate on the susceptor 5 side and the surface of the susceptor 5.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 Vapor growth apparatus, 2 chamber, 3 gas supply part, 3a gas storage part, 3b gas pipe, 3c gas valve, 4 raw material supply part, 4a shower plate, 5 susceptor, 6 rotation part, 7 heater, 8 gas discharge part, 9 vacuum pump, 10 radiation thermometer, 10a light source, 10b half mirror, 10c focus adjusting lens, 10d wavelength selection filter, 10e aperture, 10f light receiving unit, 10g calculation unit,

Claims (6)

A reaction chamber for causing a vapor phase growth reaction on the substrate;
A gas supply unit for supplying gas to the reaction chamber;
Heating means for heating the substrate;
A radiation thermometer disposed above the film growth surface of the substrate and measuring the temperature of the film growth surface;
The radiation thermometer corrects at least one of the phase of the thermal radiation intensity and the phase of the reflectance so that the phase of the thermal radiation intensity of the film growth surface of the substrate matches the phase of the reflectance. A vapor phase growth apparatus comprising: a calculation unit that obtains the temperature of the film growth surface based on the thermal radiation light intensity and the reflectance that are phase-matched by the correction.   2. The calculation unit corrects the reflectance phase according to the phase of the thermal radiation light intensity, or corrects the thermal radiation light intensity phase according to the reflectance phase. The vapor phase growth apparatus described in 1. The calculator is
A phase detection unit for detecting a current phase from a temporal change in the thermal radiation light intensity measured by the radiation thermometer;
Based on the reflected light intensity measured by the radiation thermometer, a reflectance detector that detects at least one of the nearest maximum value and minimum value of the reflectance of the film growth surface of the substrate;
The phase of the modeled reflectance function is adjusted based on the phase detected by the phase detector, and at least one of the latest maximum value and minimum value detected by the reflectance detector. And a fitting unit for adjusting the fitting parameter of the reflectance function,
3. The vapor phase growth apparatus according to claim 1, further comprising: a temperature calculation unit configured to calculate the temperature based on the reflectance function adjusted by the fitting unit and the heat radiation light intensity. The reflectance function is
A ・ (sin (φ) +1) ・ (1−α (sin (φ) +1)) + B
Is an expression represented by
Fitting parameters A and B are adjusted based on the latest maximum value and minimum value detected by the reflectance detection unit,
The vapor phase growth apparatus according to claim 3, wherein the phase φ is adjusted based on a current phase detected by the phase detection unit. A temperature detection method for detecting a temperature of the substrate when supplying a source gas to the substrate while heating the substrate by a heating means and sequentially growing a single film or a plurality of films on the substrate,
A radiation thermometer is disposed above the film growth surface of the substrate, and the heat radiation intensity and reflected light intensity from the substrate are measured,
Correcting at least one of the phase of the thermal radiation light intensity and the phase of the reflectance so that the phase of the thermal radiation light intensity and the phase of the reflectance are matched,
A temperature detection method for obtaining a temperature of the film growth surface based on the thermal radiation light intensity and the reflectivity whose phases are matched by the correction. Detecting the phase of the thermal radiation intensity measured by the radiation thermometer;
Detecting the latest maximum and minimum values of reflectance measured by the radiation thermometer;
Aligning the phase of the modeled reflectance function with the detected phase of the heat radiation light intensity, and adjusting the fitting parameter of the reflectance function to the nearest maximum and minimum values of the detected reflectance To correct the reflectance,
The temperature detection method according to claim 5, wherein the temperature is calculated based on the corrected reflectance and the heat radiation light intensity.

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