JP2010045198A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce generation and/or sticking of fine particles to a wafer by a simple technique. <P>SOLUTION: A method of manufacturing a semiconductor device includes: a step of raising the temperature of a reaction furnace; a step of carrying one or a plurality of wafers in the temperature-raised reaction furnace; and a step of heat-treating the wafer. In carrying-in of the wafer, a heat shielding plate is arranged in front in the carrying-in direction of the wafer, and the wafer is carried in the reaction furnace together with the heat shielding plate. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a semiconductor device manufacturing method, and more particularly to a semiconductor device manufacturing method capable of reducing particles generated / attached in a reaction furnace.

2. Description of the Related Art Conventionally, a semiconductor device manufacturing process uses, for example, a CVD (chemical vapor deposition) method in which a desired thin film is vapor-grown on a wafer surface by a single-wafer method or a batch method. In particular, in the batch-type CVD method, a plurality of wafers can be mounted on a support member called a ladder boat so as to be juxtaposed in the vertical direction, and a large number of wafers can be processed at once in a reaction furnace.
In such a method, generally, the support member / wafer at about room temperature is introduced into the heated reaction furnace, so that the temperature inside the reaction furnace rapidly decreases after the wafer is transferred. Therefore, in order to compensate for this temperature drop, control for maintaining or raising the temperature inside the reactor is usually performed. Specifically, measures such as increasing the power of the external heater of the reaction furnace during wafer transfer are taken.

When heat treatment such as the CVD method described above is involved, a difference in thermal expansion occurs between the ladder boat and the wafer due to the property of heating the wafer mounted on the ladder boat, and fine particles are generated due to the friction. Sometimes. In particular, as the wafer diameter increases, the 300 mm diameter wafer is affected by its own weight, and the generation of fine particles due to friction becomes significant.
In particular, in recent years, since the miniaturization of product patterns has progressed, further suppression of particles is required.

For example, in order to reduce the friction between the wafer and the support member, a method has been proposed in which a non-reactive heating or cooling gas is injected toward the wafer to moderate the temperature change of the wafer itself. (For example, patent document 1).
In addition, after introducing the wafer into the reaction furnace, a method has been proposed in which the wafer is floated by gas so that the wafer and the support member do not physically come into contact with each other (for example, Patent Document 2).
JP 2000-133606 A JP 2007-134450 A

However, the method of gradually increasing the temperature of the wafer and the support member complicates the control of the reaction sequence and, in addition, requires time, resulting in an increase in manufacturing cost.
Further, in the heating or cooling gas injection to the wafer, as the diameter of the wafer increases, problems still remain in the temperature control within the surface.
Further, in the method of levitating the wafer, the gas flow for levitating increases as the dead weight of the large-diameter wafer increases, and turbulence is generated in the reaction furnace. This causes a new problem that, in addition to the friction between the wafer and the support member, a further factor that causes fine particles to adhere to the wafer occurs.

  The present invention has been made in view of the above problems, and an object thereof is to reduce the generation and / or adhesion of fine particles to a wafer by a simple method.

  According to one embodiment, in the method for manufacturing a semiconductor device, when one or a plurality of wafers are loaded into a heated reactor, a heat shield plate is disposed in front of the wafer loading direction, and the heat shield plate At the same time, the wafer is carried into the reactor.

  In the disclosed method for manufacturing a semiconductor device, the temperature of the wafer can be gradually increased by suppressing the amount of heat applied to the wafer when the wafer is carried into the reaction furnace. As a result, the thermal expansion of the wafer can be minimized and the generation of particles due to the thermal expansion of the wafer can be prevented.

  A reactor used in a method for manufacturing a semiconductor device according to an embodiment of the present invention is a reactor capable of realizing a process involving heat treatment such as film formation, annealing, etching, ashing, oxidation, or diffusion in a semiconductor manufacturing process. Any principle may be used.

For example, a reaction furnace 10 in a heat treatment apparatus such as a general batch type thermal CVD apparatus as shown in FIG. 1 can be exemplified. Such a reaction furnace 10 is preferably provided with a heating means so as to cover at least the accommodation position of the wafer 13 so that the temperature in the reaction furnace 10 in which the wafer 13 is held is uniform. As the heating means, for example, a heater 12, a hot gas inlet, and the like are preferably provided. Specifically, one or more heaters 12 or gas inlets are disposed outside the outer surface and / or the upper surface of the chamber 11.
Also, usually, a plurality of gas inlets (not shown) are provided on the upper, lower and / or side surfaces. In addition, a thermocouple 15 is disposed in an appropriate place inside the reaction furnace 10 in order to measure the temperature in the reaction furnace.

The size of the reaction furnace is not particularly limited, and various sizes are included. In particular, those applicable to recent large-diameter wafers are suitable. For example, those applicable to carry in and process a wafer having a diameter of 300 mm or more are preferable.
Examples of the shape of the reaction furnace include various types such as a vertical type, a cylinder type, a cluster type, and a single wafer type. Among them, a vertical type (for example, see FIG. 1) is preferred in which the chamber is arranged in the vertical or substantially vertical direction and the wafer can be loaded from below to above.

Moreover, as shown in FIG. 1, the thing of the form which can arrange | position and process one or more wafer 13 so that it may face the vertical direction of the reaction furnace 10, ie, an up-down direction, is preferable.
As described above, in a reaction furnace that includes a vertical chamber and carries wafers in and out in the vertical direction, the amount of heat that is abruptly applied to the wafer transferred to the deep part of the reaction furnace tends to increase particularly immediately after the wafer is carried in. However, an embodiment of the present invention is effective in reducing the generation of fine particles and / or adhesion by mitigating such a sudden heat load on the wafer.

  Usually, before carrying a wafer into a reaction furnace, the temperature in the reaction furnace is raised to a predetermined temperature. The temperature in this case can be appropriately adjusted according to the processing mode, the type of gas used, the number and size of wafers to be carried in, and the like. For example, about 300-800 degreeC is illustrated as the temperature in the heated reaction furnace, about 450-650 degreeC is suitable, and about 500-600 degreeC is preferable. The method of raising the temperature of the reaction furnace to such a temperature can be appropriately selected depending on the apparatus used. For example, the temperature is raised by radiant heat from a heater disposed inside or outside the reaction furnace, or inside the furnace heated by the heater. A temperature rise by conductive heating with a gas can be mentioned.

Subsequently, the wafer is carried into the heated reaction furnace.
As the wafer, any of elemental semiconductors such as silicon and germanium and compound semiconductors such as GaAs and InP may be used.
As described above, it is preferable to carry in the wafer from the lower side of the reaction furnace. However, for such carry-in, for example, a support capable of supporting a plurality of wafers as shown in FIG. It is preferable to use the member 14. Such a support member 14 can easily carry in a plurality of wafers, and can set and process the wafers at appropriate positions in the reaction furnace.

As shown in FIG. 1, the support member 12 is a vertical type, and when using a reactor in which a wafer is carried in and out in the vertical direction, one or more wafers, usually about 50 to 100 wafers, are used. Those that can be mounted so as to face each other in the vertical direction are preferable.
The support member 12 can be formed using a material that can withstand the reaction temperature in the reaction furnace and / or an insulating material. Further, it is preferable to use a support member having a small difference (for example, about 0.5 or less) from the thermal expansion coefficient of the wafer to be mounted. Specifically, the support member 14 is preferably formed using quartz. The outer shape of the support member is exemplified by a substantially cylindrical shape having a slightly larger diameter than the wafer (see FIG. 2B). Specifically, the diameter is about 150 to 300 mm, preferably about 200 to 300 mm. The support member 14 is provided with 2 to 5 protrusions 14a for mounting the wafer 13 at a predetermined pitch (see P in FIG. 2A). More preferably, the protrusions 14a are provided at three locations.
In general, the pitch on which the wafer is placed can be appropriately adjusted according to the form of the reaction furnace, the processing mode, the type of gas used, and the like. However, since the thickness of the wafer is generally about 0.5 to 1 mm, for example, the pitch for mounting the wafer is about 5 to 15 mm. From another point of view, the pitch is about 10 to 15 times the thickness of the wafer.

  In one embodiment, when a wafer is carried in, a heat shield plate is disposed in front of the wafer loading direction, and the wafer is carried into the reactor together with the heat shield plate. The heat shield plate has a role of protecting the wafer from being directly exposed to a high temperature atmosphere in front of the loading direction at the time of loading. In addition, the heat shield plate has a role of suppressing the amount of heat applied to the wafer in the reaction furnace by absorbing the amount of heat in the reaction furnace in the vicinity of the front in the loading direction. In other words, the heat shield plate can reduce the amount of heat applied to the wafer carried into the reactor by absorbing the heat shield plate itself. Thereby, the rapid temperature change of a wafer can be relieved and generation | occurrence | production of the fine particle by contact etc. with a wafer and a supporting member can be suppressed.

  A wafer with such a heat shield plate can be carried into the reaction furnace using, for example, a support member as described above. For example, as shown in FIG. 2A, the support member includes one or more heat shield plates 14b on the front side in the direction of carrying into the reaction furnace (the direction of arrow A). The shape of the heat shield plate is typically exemplified by a plate shape slightly larger than the wafer. Moreover, as long as it can protect from a high temperature atmosphere as described above and can absorb heat appropriately, a part of the surface may have irregularities or holes regularly or irregularly. . Such a surface shape can further increase the surface area and promote heat absorption.

  The thickness of the heat shield plate is not particularly limited, and can be appropriately adjusted depending on, for example, the temperature in the reaction furnace, the thickness and material of the heat shield plate, and the like. For example, in the temperature range in the reaction furnace as described above, the thickness of the heat shield plate is about 1 to 20 times, preferably about 1 to 10 times the thickness of the wafer. Moreover, about 1-10 mm about another viewpoint, Preferably about 2-5 mm is mentioned. This is because if the thickness is too thin, a sufficient heat shielding effect cannot be obtained, and if the thickness is too thick, the stability of the temperature of the reaction furnace may be adversely affected after loading.

  In the case of the thickness etc. of the range mentioned above, about 4-20 sheets are illustrated, for example, about 8-20 sheets are suitable, and about 10-16 sheets are preferable. If the number of heat shield plates is too small, the effect of suppressing the temperature rise of the wafer cannot be sufficiently exerted, and it becomes difficult to reduce the amount of friction between the wafer and the support member. Moreover, if the number of heat shield plates is too large, excessively absorbing heat may adversely affect the temperature stability in the reaction furnace after wafer loading, such as excessively reducing the temperature in the reaction furnace. is there. In addition, it takes time to stabilize the temperature of the heat shield plate itself, resulting in an increase in process time and a reduction in production efficiency. When the heat shield plates are arranged in this range, the number of wafers mounted on the support member described above substantially corresponds to the total number of wafers and heat shield plates.

In the case of the thickness in the above-described range, the pitch of the heat shield plates is, for example, about 0.5 to 2 mm, and preferably about 0.6 to 1.2 mm. From another point of view, the pitch is about 10 to 15 times the thickness of the wafer mounted on the support member.
The shape, thickness, pitch, and the like of the heat shield plate are preferably the same for all the heat shield plates, but may be partially or entirely different.

  As shown in FIG. 2A, the position of the heat shield plate does not necessarily have to be arranged at the front end in the loading direction (arrow A direction), and a small space is formed in the front. May be. When a plurality of heat shield plates are arranged, it is preferable that the heat shield plates are arranged so as to face each other in the vertical direction, like the wafer. Further, if a heat shield plate is provided on the forefront surface in the wafer loading direction, a heat shield plate may be disposed between the wafers.

  The heat shield plate is formed of a material that can withstand the temperature in the reactor, an insulating material, a material that can effectively shield heat when introducing a wafer into the reactor, and / or a material that can efficiently absorb heat. It is preferable. In particular, in consideration of integration with the support member described later, the difference in thermal expansion coefficient with the support member is small (for example, about 0.5 or less), or substantially the same (for example, about ± 0.1 difference). The same thing is preferable. For this reason, the heat shield plate is preferably made of the same material as the support member, and more preferably made of quartz.

  Further, as described above, the heat shield plate is preferably formed integrally with the support member. The term “integration” here means that there is no gap between the support member and the reaction gas or the like. The integration includes a method of forming a heat shield plate at the time of forming the support member and forming both of them as one member at the same time, forming them as separate parts, and joining them together by welding, for example. It is done.

  Thus, by using the heat shield plate, when the wafer is carried into the reaction furnace held at a high temperature, the rapid temperature rise of the wafer itself can be mitigated. That is, the amount of heat applied to the wafer can be suppressed. Thereby, friction between the wafer and the support member can be reduced, and generation of fine particles and adhesion to the wafer can be prevented.

In the above-described embodiment, the temperature maintenance and / or temperature increase control in the reaction furnace may be temporarily stopped or reduced from the start of wafer transfer to the end of transfer.
As another embodiment, when the wafer is carried in, control for temporarily stopping or reducing temperature maintenance and / or temperature rise control in the reaction furnace may be performed without using the above-described heat shield plate.
Such control is performed, for example, by applying a heat amount smaller than the heat amount applied to the wafer when the temperature in the reaction furnace is maintained and / or the temperature rise control is performed from the start of wafer transfer to the end of transfer. In other words, it can be paraphrased as control for carrying in the wafer or control for suppressing the amount of heat applied to the wafer.
In addition, in order to achieve the intended effect when using the embodiment using the heat shield plate described above in combination with the embodiment for stopping / reducing the temperature maintenance / temperature increase control in the reactor, It is preferable to adjust various parameters.

  Here, the temperature maintenance control or temperature increase control in the reaction furnace is performed at least from the start of wafer loading to the end of loading in the general heat treatment apparatus described above, and the temperature drop due to wafer loading is minimized. It means all the controls that stop. In this embodiment, the temperature maintenance control or temperature increase control in the reactor includes all the temperature control performed by this type of apparatus in the field.

  Temporarily stopping the temperature maintaining control or the temperature raising control in the reaction furnace means that the power of the heating means of the reaction furnace is turned off at least from the start of wafer transfer to the end of transfer, preferably only during this period. . Even if the temperature control of the reactor is automatically controlled, it is set in advance so that the heating means is not turned on even if any temperature fluctuation occurs between the start of wafer transfer and the end of transfer. It means to keep.

Temporarily reducing the temperature maintenance control or the temperature rise control in the reactor means that the power of the heating means is sufficient to cause the intended temperature change in this embodiment from the start of wafer transfer to the end of transfer. It means to reduce the amount. Even when the temperature control of the reaction furnace is automatically controlled, in the same manner as described above, it is set in advance so that the power of the heating means is not maintained or raised between the start of wafer transfer and the end of transfer. Means.
In this embodiment, it is preferable to temporarily stop the temperature maintenance control or the temperature rise control in the reaction furnace at least from the start of the wafer loading to the end of the loading for the convenience of control.

  Such control results in mitigating rapid temperature changes of the wafer. That is, the temperature of the wafer is gradually increased to suppress generation of fine particles due to friction between the wafer and the support member.

  In the control for minimizing the above general temperature drop, the temperature change in the reaction furnace at the time of wafer loading is usually less than 5 ° C., although it varies depending on the size of the reaction furnace to be used and the set temperature. It is set to a temperature drop below 3 ° C or within 3 ° C. However, in this embodiment, due to the unique control as described above, as a result, the temperature change in the reactor is reduced by 2 ° C. from the start of wafer transfer to the end of transfer, compared to the general control described above. It can be increased by about 3 ° C. or more. Moreover, it is preferable that the temperature change in the reaction furnace is increased at about 7 ° C. or less, compared to general control.

  Specifically, it is suitable that the temperature drop in the reaction furnace is 4 ° C. or higher, and preferably 5 ° C. or higher, from the start of wafer loading to the end of loading. If the temperature drop is too small, the amount of heat applied to the wafer cannot be relaxed sufficiently. This has been confirmed based on experimental results described later. Moreover, about 10 degreeC is suitable for the upper limit of temperature fall. This is because if the temperature drop is too great, the subsequent reaction process is adversely affected, and a longer time is required to bring the loaded wafer to the reaction temperature, resulting in a complicated manufacturing process and an increase in manufacturing cost. Further, it has been confirmed that no further reduction in the amount of particles adhering to the wafer is observed from above about 10 ° C. Therefore, considering the manufacturing efficiency and the particle reduction effect comprehensively, the necessary and sufficient effect intended by this embodiment can be exhibited with a temperature drop of 10 ° C. or less.

  In general, the loading of wafers into the reaction furnace varies depending on the set temperature of the reaction furnace, the size and number of wafers used, etc., but typically within 5 minutes, and within 4 minutes is suitable, and 3 minutes. Is preferred. This is because a rapid temperature drop in a very short time may deteriorate the temperature distribution in the reactor and adversely affect the subsequent manufacturing process.

  After carrying the wafer into the reactor, the wafer is heat treated. The heat treatment in this case is not particularly limited as long as it is performed under a high temperature load, and examples thereof include film formation by CVD and the like, thermal diffusion, thermal oxidation, annealing, ashing, etching, and the like. The temperature in this case is not particularly limited, and for example, about 300 ° C. to 1200 ° C. is exemplified. This heat treatment is usually carried out by maintaining or raising the temperature of the reaction furnace without lowering the temperature of the reaction furnace after carrying in the wafer. The heat treatment is preferably performed in the reaction furnace and / or after the wafer temperature is stabilized.

An embodiment of a method for manufacturing a semiconductor device will be described in detail below.
Example As a device having a reaction furnace, a batch-type vertical thermal CVD device having a heater as a heating means 12 on the outer periphery of the side surface of the chamber 11 as shown in FIG. 1 was used.
As a wafer support member, a quartz ladder boat as shown in FIG. 2 was used. This ladder boat is capable of mounting a 300 mm diameter wafer (thickness: 0.8 mm), and is provided with 13 heat shield plates integrated therewith. The thickness of the heat shield is about 1 mm.

Using such a thermal CVD apparatus and a ladder boat, the temperature of the reaction furnace was raised and set to 500 ° C.
After the temperature was stabilized, the ladder boat loaded with the wafer was loaded into the heated reaction furnace for 3 minutes from the start of loading to the end of loading. The reactor during this period was set to 500 ° C. ± 1 ° C. by controlling the on / off of the heater and / or the strength of the power by cascade control of the internal thermocouple 15 and the external heater.

  In this way, the wafer was carried into the heated reaction furnace and the back surface of the wafer after heat treatment was observed with a metal microscope and the state of generation of particles was observed. The results are shown in Table 1.

  For reference, except that the number of heat shield plates in the ladder boat is reduced to eight or three, the backside observation of the wafer after heat treatment and observation of the generation of particles are the same as in the above example. Went. The results are shown in Table 1.

表１から、金属顕微鏡によるウェハの裏面観察では、遮熱板８枚以上で、摩擦による傷を１．０ｍｍ未満に低減できることが確認された。つまり、ウェハ裏面とラダーボートとの接触による傷を比較的短くできることが確認された。
また、パーティクルの発生状況の観察では、遮熱板８枚以上では、各パーティクルが局所的に独立して点在する程度であることが確認された。一方、３枚以下では、集落状に、パーティクルが集中して付着する部位が認められた。

From Table 1, it was confirmed that the scratches due to friction can be reduced to less than 1.0 mm with 8 or more heat shield plates in the backside observation of the wafer with a metal microscope. That is, it was confirmed that the damage caused by contact between the wafer back surface and the ladder boat can be made relatively short.
Further, in the observation of the generation state of the particles, it was confirmed that each particle was scattered locally and independently with 8 or more heat shield plates. On the other hand, in three or less sheets, the part which a particle concentrates and adheres to a colony form was recognized.

Furthermore, as described above, the temperature change in the reaction furnace when the wafer was carried into the heated reaction furnace was measured using three types of ladder boats. The results are shown in FIGS.
In FIGS. 3A to 3C, the point A means the start of carrying in the wafer and the point B means the completion of carrying in the wafer, and the time is 3 minutes. Moreover, in Fig.3 (a), it was confirmed that the temperature of the reactor has fallen about 6 degreeC. Similarly, it was confirmed that the temperature was lowered by about 4 ° C. in FIG. 3B and about 2 ° C. in FIG. 3C.

  From these results, when a wafer is carried in, by using a heat shield plate, a temperature change larger than the temperature range that changes when the temperature inside the reactor is maintained and / or the temperature rise control is obtained. It was confirmed that it was possible. That is, the amount of heat applied to the wafer during loading of the wafer can be suppressed as a result. As a result, the temperature of the wafer can be increased more gradually, and rapid thermal expansion can be reduced.

  Further, from the results of FIGS. 3A to 3C, the amount of heat applied to the wafer by relatively large temperature change in the reaction furnace when the wafer is carried in regardless of the presence or absence of the heat shield plate. It was confirmed that it can be suppressed.

Regarding the above embodiment, the following supplementary notes are disclosed.
(Appendix 1)
A step of raising the temperature of the reaction furnace;
Carrying one or more wafers into the heated reaction furnace;
A method of manufacturing a semiconductor device including a step of heat-treating the wafer,
A semiconductor device manufacturing method, wherein a heat shield plate is arranged in front of the wafer loading direction when the wafer is carried in, and the wafer is carried into the reaction furnace together with the heat shield plate.
(Appendix 2)
A step of raising the temperature of the reaction furnace;
Carrying one or more wafers into the heated reaction furnace;
A method of manufacturing a semiconductor device including a step of heat-treating the wafer,
A method of manufacturing a semiconductor device, wherein temperature maintenance and / or temperature rise control in a reaction furnace is temporarily stopped or reduced from the start of wafer transfer to the end of transfer.

(Appendix 3)
One or more heat shields are arranged on the upper part of a support member capable of mounting one or a plurality of wafers so as to face each other in the vertical direction, and the support is installed in a vertical reactor disposed in a vertical or substantially vertical direction. The method of appendix 1, wherein the member is carried together with the wafer from below to above.
(Appendix 4)
Any one of Supplementary notes 1 to 3, wherein the wafer is carried in using a supporting member for carrying in the wafer, and the heat shielding plate is arranged in the number of 4 to 20 in front of the supporting member in the wafer carrying direction. Or one way.
(Appendix 5)
The wafers are carried in using a supporting member for carrying in the wafer, and the heat shield plate is arranged on the supporting member so as to face each other with a thickness of 1 to 20 times the thickness of the wafer. Any one method.

(Appendix 6)
The method according to supplementary note 1, wherein the temperature maintenance and / or temperature rise control in the reaction furnace is temporarily stopped or reduced from the start of the wafer loading to the end of the loading.
(Appendix 7)
The method according to any one of appendices 1 to 6, wherein a temperature drop in the reaction furnace is set to 4 ° C. or more and 10 ° C. or less from the start of loading of the wafer to completion of loading.
(Appendix 8)
The method according to any one of appendices 1 to 8, wherein the time from the start of wafer transfer to the end of transfer is within 5 minutes.
(Appendix 9)
The method according to any one of appendices 3 to 5, wherein the heat shield plate is formed of a material having the same thermal expansion coefficient as that of the support member.
(Appendix 10)
The method of any one of additional notes 3 to 5 and 9, wherein the heat shield plate is formed integrally with the support member.

It is a schematic longitudinal cross-sectional view of the principal part of the reaction furnace utilized with the manufacturing method of the semiconductor device of this invention. It is the longitudinal cross-sectional view and top view of the supporting member of a wafer which are utilized with the manufacturing method of the semiconductor device of this invention. It is a graph which shows the temperature change in the reaction furnace at the time of performing peculiar control in the manufacturing method of the semiconductor device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reactor 11 Chamber 12 Heating means 13 Wafer 14 Support member 14a Protrusion part 14b Heat shield plate 15 Internal thermocouple

Claims (6)

A step of raising the temperature of the reaction furnace;
Carrying one or more wafers into the heated reaction furnace;
A method of manufacturing a semiconductor device including a step of heat-treating the wafer,
A semiconductor device manufacturing method, wherein a heat shield plate is arranged in front of the wafer loading direction when the wafer is carried in, and the wafer is carried into the reaction furnace together with the heat shield plate.   The said wafer is carried in using the supporting member for wafer carrying in, and the said heat shielding board is arrange | positioned 4-20 sheets so that it may mutually face in the loading direction of the wafer of the said supporting member. Method.   The wafer is carried in using a supporting member for carrying in the wafer, and the heat shield plate is arranged on the supporting member so as to face each other with a thickness of 1 to 20 times the thickness of the wafer. The method described in 1. A step of raising the temperature of the reaction furnace;
Carrying one or more wafers into the heated reaction furnace;
A method of manufacturing a semiconductor device including a step of heat-treating the wafer,
A method of manufacturing a semiconductor device, wherein temperature maintenance and / or temperature rise control in a reaction furnace is temporarily stopped or reduced from the start of wafer transfer to the end of transfer.   5. The method according to claim 1, wherein a temperature drop in the reaction furnace is set to 4 ° C. or more and 10 ° C. or less from the start of loading of the wafer to the end of loading.   The method according to any one of claims 1 to 6, wherein a time from the start of loading of the wafer to the end of loading is within 5 minutes.

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