JP2008140945A - cat-CVD DEVICE AND FILAMENT REPLACEMENT METHOD - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cat-CVD device and a filament replacement method that facilitate filament replacement even when using a material having a high ductile-brittle transition temperature as a filament material. <P>SOLUTION: The cat-CVD device 100 is provided with a vacuum chamber 30 for storing a growth substrate 200, a filament 1 arranged in the vacuum chamber 30, a sending-out roller 20 for sending out the filament 1 into the vacuum chamber 30, a winding pinch roller 40 for winding the filament 1 from inside the vacuum chamber 30, and a heater 41 that heats the filament 1 at the winding pinch roller 40 side until a filament temperature reaches a temperature higher than a ductile-brittle transition temperature of the filament 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cat-CVD apparatus and a filament exchange method that include a vacuum chamber containing at least a growth substrate and a filament disposed in the vacuum chamber.

  Conventionally, as an apparatus for forming a thin film on a growth substrate, an apparatus (cat-CVD apparatus) or a plasma CVD apparatus using catalytic chemical vapor deposition (cat-CVD) is known.

  Since plasma discharge is used in the plasma CVD apparatus, depending on the material constituting the thin film, the surface of the thin film may be adversely affected. On the other hand, in the cat-CVD apparatus, since plasma discharge is not used, there is little adverse effect on the surface of the thin film.

  Specifically, the cat-CVD apparatus includes a vacuum chamber that accommodates the growth substrate, a filament disposed in the vacuum chamber, a gas supply path for supplying a source gas into the vacuum chamber, and a vacuum chamber. A gas discharge passage for discharging the source gas. In the cat-CVD apparatus, the filament is heated by passing an electric current through the filament, and the source gas is decomposed by the heated filament until it reaches a high temperature. As a result, a thin film is formed on the growth substrate.

  Here, when a Si-based thin film such as an amorphous Si film is formed by a cat-CVD apparatus, it is necessary to heat the filament until it reaches a sufficiently high temperature (for example, 1600 ° C.). When the temperature of the filament is not sufficiently high, Si adheres to the filament surface, the metal constituting the filament reacts with Si, and alloying (silicidation) proceeds. Therefore, the filament is generally used after being sufficiently heated. However, there are portions where the temperature of the filament cannot be sufficiently increased, such as the end of the filament and the vicinity of the contact. In such a portion, it is difficult to avoid the adhesion of Si and the occurrence of silicidation. Therefore, breakage of the filament due to an increase in electrical resistance is inevitable.

  As described above, since filament breakage is unavoidable, replacement of the filament is necessary. As a method for replacing the filament, a method of opening the vacuum chamber and replacing the filament can be considered. However, when the vacuum chamber is opened, a dead time (for example, 10 hours or more) such as a time for returning the inside of the vacuum chamber to a vacuum state or a time for performing test film formation occurs.

On the other hand, the cat-CVD apparatus which has a mechanism which sends out a filament, and a mechanism which winds a filament is proposed (for example, patent documents 1).
Japanese Patent Laid-Open No. 7-254666 (Claim 1, FIG. 1, etc.)

  Here, consider the case where a material (for example, tungsten) having a ductile-brittle transition temperature higher than room temperature is used as the filament material in the above-described cat-CVD apparatus. In this case, when the temperature of the filament decreases to room temperature, the filament becomes brittle due to the ductile-brittle transition that occurs with the temperature decrease of the filament. For this reason, when winding a filament, a filament will fracture | rupture brittlely. That is, it is difficult to exchange filaments in the above-described cat-CVD apparatus.

  The ductile-brittle transition is a phenomenon in which a metal material becomes extremely brittle as the temperature of the metal material (filament) decreases, and is common to body-centered cubic crystal metals (eg, steel, tungsten, molybdenum, etc.). This phenomenon occurs. The ductile-brittle transition temperature is a temperature at which a ductile-brittle transition occurs. The ductile-brittle transition temperature is determined by the type of metal material, and is also affected by the crystal grain size and the amount of impurities.

  For example, the ductile-brittle transition of steel (Fe) will be described with reference to FIG. FIG. 5 is a diagram showing a ductile-brittle transition curve of steel (Fe). In FIG. 5, the horizontal axis is the test temperature (° C.), and the vertical axis is the absorbed energy (E / J). The ductile-brittle transition temperature generally refers to a temperature at which the energy required for fracture of a metal material is about 50% of the energy required for ductile fracture (on the high temperature side).

  Next, the ductile-brittle transition temperature of a typical high-temperature metal material will be described with reference to FIG. FIG. 6 is a diagram showing a ductile-brittle transition temperature of a typical high-temperature metal material.

  As shown in FIG. 6, molybdenum (Mo) and tungsten (W) are brittle at room temperature. Therefore, it can be seen that when molybdenum (Mo) or tungsten (W) is used as the filament material, the filament exhibits brittleness at room temperature. In the VIa group to which tungsten (W) belongs, when hydrogen (H) is contained as an impurity, the influence of hydrogen (H) on the ductile-brittle transition temperature is small. On the other hand, when carbon (C), nitrogen (N), oxygen (O), etc. are contained as impurities, the effect of carbon (C), nitrogen (N), oxygen (O), etc. on the ductile-brittle transition temperature Is big.

  Therefore, the present invention has been made to solve the above-described problem, and even when a material having a high ductile-brittle transition temperature is used as the filament material, the filament can be easily replaced. An object of the present invention is to provide a cat-CVD apparatus and a filament exchange method.

  One feature of the present invention is that a cat-CVD apparatus (cat-CVD apparatus 100) includes a vacuum chamber (vacuum chamber 30) for accommodating at least a growth substrate, and a filament (filament 1) disposed in the vacuum chamber. ) Is a feeding section (feeding roller 20) that feeds the filament into the vacuum chamber, a winding section (winding pinch roller 40) that winds the filament from the vacuum chamber, and a ductile-brittle transition of the filament. The gist is to include a winding side heating section (heater 41) that heats the filament on the winding section side until the temperature becomes higher than the temperature.

  According to this characteristic, the winding side heating unit heats the filament on the winding unit side until the temperature becomes higher than the ductile-brittle transition temperature of the filament. Therefore, it is possible to suppress the filament from being brittlely broken in the vacuum chamber due to the ductile-brittle transition caused by the temperature decrease of the filament on the winding portion side. Therefore, even when a material having a high ductile-brittle transition temperature (for example, tungsten) is used as the filament material, the filament can be easily replaced.

  One feature of the present invention is that, in the one feature described above, a delivery side heating section (heater 21) that heats the filament on the delivery section side until the temperature becomes higher than the ductile-brittle transition temperature of the filament. The cat-CVD apparatus further includes a control unit (control unit 120) that controls the heating amount of the winding side heating unit and the feeding side heating unit, and the control unit is more than the winding unit side than the winding unit side. The gist is to control the heating amount so that the temperature of the filament becomes higher on the part side.

  One feature of the present invention is that, in a cat-CVD apparatus comprising a vacuum chamber containing at least a growth substrate, and a filament disposed in the vacuum chamber, the filament exchange method for exchanging the filament includes the filament. Delivering the filament into the vacuum chamber; and winding the filament from within the vacuum chamber, wherein the filament is wound up until the temperature is higher than the ductile-brittle transition temperature of the filament. The gist is to take up the filament while heating.

  One feature of the present invention is that in the one feature described above, in the step of sending out the filament, the filament is sent out while heating the filament until the temperature becomes higher than the ductile-brittle transition temperature of the filament, and the filament In the step of feeding and the step of winding the filament, the filament is heated so that the temperature of the filament is higher on the side of winding the filament than on the side of feeding the filament.

  One feature of the present invention is that, in the one feature described above, in the step of feeding the filament and the step of winding the filament, a current is supplied to the filament.

  According to the present invention, it is possible to provide a cat-CVD apparatus and a filament exchange method capable of easily exchanging a filament even when a material having a high ductile-brittle transition temperature is used as a filament material. Can do.

  Hereinafter, a cat-CVD apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  In the following, the ductile-brittle transition is a phenomenon in which when the temperature of the metal material (filament) is lowered, the metal material becomes extremely brittle as the temperature of the metal material is lowered. The ductile-brittle transition temperature is a temperature at which a ductile-brittle transition occurs.

[First Embodiment]
(Configuration of cat-CVD apparatus)
Hereinafter, the configuration of the cat-CVD apparatus according to the first embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of a cat-CVD apparatus 100 according to the first embodiment.

  As shown in FIG. 1, the cat-CVD apparatus 100 includes a bobbin 10, a delivery roller 20, a vacuum chamber 30, a take-up pinch roller 40, and a waste material container 60.

  The bobbin 10 has a columnar shape configured to be rotatable. A filament 1 is wound around the bobbin 10. The filament 1 is made of a material (for example, tungsten) having a ductile-brittle transition temperature higher than room temperature.

  The delivery roller 20 is a mechanism that delivers the filament 1 into the vacuum chamber 30. Specifically, the delivery roller 20 has a cylindrical shape configured to be rotatable. The filament 1 is stretched around the feed roller 20.

  In the vicinity of the delivery roller 20, a heater 21 for heating the filament 1 stretched over the delivery roller 20 is provided. The heater 21 heats the filament 1 until the temperature becomes higher than the ductile-brittle transition temperature of the filament 1. For example, when the filament 1 is made of tungsten, the ductile-brittle transition temperature is about 300 ° C. Of course, the ductile-brittle transition temperature of the filament 1 varies depending on the material of the filament 1, the crystal grain size of the filament 1, the amount of impurities contained in the filament 1, and the like.

  The vacuum chamber 30 is a chamber that accommodates at least the growth substrate 200. Specifically, the vacuum chamber 30 includes a delivery chamber 30a, a reaction chamber 30b, and a take-up chamber 30c.

  The delivery chamber 30a is provided with a gas supply path 31a, a gas discharge path 32a, a bobbin 10, a delivery roller 20, and a heater 21.

The gas supply path 31a communicates with the delivery chamber 30a and is a flow path for supplying gas such as Ar and H ₂ into the delivery chamber 30a. A gas such as Ar or H ₂ is filled in the delivery chamber 30a in order to keep the pressure in the gas supply path 31a higher than the pressure in the reaction chamber 30b.

The gas discharge path 32a communicates with the inside of the delivery chamber 30a, and is a flow path for exhausting gases such as Ar and H ₂ from the delivery chamber 30a.

  In the reaction chamber 30b, a gas supply path 31b, a gas discharge path 32b, a pedestal portion 33, and a heater 34 are provided.

The gas supply path 31b communicates with the reaction chamber 30b, and is a flow path for supplying a source gas (for example, SiH ₄ ) into the reaction chamber 30b.

The gas discharge path 32b communicates with the reaction chamber 30b, and is a flow path for discharging a source gas (for example, SiH ₄ ) from the reaction chamber 30b. The gas discharge path 32b is also used to discharge air (atmosphere) from the reaction chamber 30b in order to make the reaction chamber 30b in a vacuum state.

  The pedestal portion 33 has a placement surface (not shown) on which the growth substrate 200 is placed. The heater 34 heats the growth substrate 200 placed on the pedestal portion 33.

  In the winding chamber 30c, a gas supply path 31c, a gas discharge path 32c, a winding pinch roller 40, a heater 41, a waste material container 60, and a crusher 61 are provided.

The gas supply path 31c communicates with the winding chamber 30c and is a channel for supplying a gas such as Ar or H ₂ into the winding chamber 30c. Gases such as Ar and H ₂ are filled in the winding chamber 30c in order to keep the pressure in the winding chamber 30c higher than the pressure in the reaction chamber 30b.

The gas discharge path 32c communicates with the take-up chamber 30c and is a flow path for discharging gases such as Ar and H ₂ from the take-up chamber 30c.

  The take-up pinch roller 40 is constituted by a roller 40A and a roller 40B having a drive source, and is a mechanism for taking up the filament 1 from the reaction chamber 30b. Specifically, the roller 40A and the roller 40B have a columnar shape configured to be rotatable. The filament 1 is sandwiched between the roller 40A and the roller 40B.

  A heater 41 (a heater 41A and a heater 41B) is provided in the vicinity of the take-up pinch roller 40. The heater 41A and the heater 41B heat the filament 1 until the temperature becomes higher than the ductile-brittle transition temperature of the filament 1.

  The filament 1 taken up by the take-up pinch roller 40 becomes lower than the ductile-brittle transition temperature of the filament 1 by a method such as natural cooling, so that the filament 1 becomes brittle and the filament 1 is easily crushed. .

  The waste material container 60 is a container for storing the filament 1 cooled by a method such as natural cooling. The waste material container 60 is provided with a crusher 61A such as a cutter and a crusher 61B. The crusher 61A and the crusher 61B move along the A direction to crush the filament 1.

  A connection point 71 for connecting the filament 1 and the current supply line 71 </ b> A is provided on the delivery roller 20 side of the vacuum chamber 30. Similarly, a connection point 72 for connecting the filament 1 and the current supply line 72 </ b> A is provided on the winding pinch roller 40 side of the vacuum chamber 30. In addition, about the connection point 71 and the connection point 72, the structure which the sending-out roller 20 and the winding pinch roller 40 each serve as a connection point may be sufficient.

  Here, when a thin film is formed on the growth substrate 200, a current flows through the filament 1 between the connection point 71 and the connection point 72. As a result, the filament 1 is heated to a temperature necessary for forming the thin film (for example, 1700 ° C.).

  It should be noted that the temperature of the filament 1 varies depending on the region in the cat-CVD apparatus 100. Specifically, in the region a, the temperature of the filament 1 may be maintained at a room temperature lower than the ductile-brittle transition temperature (for example, 300 ° C.). In the region b, since the filament 1 is heated by the heater 21, the temperature of the filament 1 is higher than the ductile-brittle transition temperature (for example, 300 ° C.). In region c, since a current flows through the filament 1, the temperature of the filament 1 rises to a temperature necessary for forming a thin film (for example, 1700 ° C.). In the region d, since the filament 1 is heated by the heater 41, the temperature of the filament 1 is higher than the ductile-brittle transition temperature (for example, 300 ° C.). In the region e, since the filament 1 is cooled by a method such as natural cooling, the temperature of the filament 1 is lower than the ductile-brittle transition temperature (for example, 300 ° C.).

  Here, the filament 1 is wound up by the winding pinch roller 40 in a state where a thin film is formed on the growth substrate 200, that is, in a state where a current flows between the connection point 71 and the connection point 72. It should be noted.

  The speed at which the filament 1 is wound by the winding pinch roller 40 depends on the length of the filament 1 from the connection point 71 to the connection point 72 (that is, the time during which the filament 1 is exposed to the source gas in the vacuum chamber 30) and the film forming conditions. Depends on. For example, when the filament 1 is made of tungsten and the length of the filament 1 from the connection point 71 to the connection point 72 is 1 m, the winding speed of the filament 1 is generally about 50 mm / hr. Is enough.

(Filament arrangement)
FIG. 1 shows the principle that the filament 1 is exchanged by the filament 1 being fed by the feed roller 20 and being wound by the take-up pinch roller 40. In an actual cat-CVD apparatus 100, a plurality of filaments 1 are generally arranged on the growth substrate 200.

  As a method of arranging a plurality of filaments on the growth substrate 200, a configuration in which the filaments are linearly stretched by a reaction unit including a feeding mechanism, a winding mechanism, a current supply mechanism, a heater, and the like is used as one set. A method of providing a plurality of sets (method A) is conceivable. As another method, as shown below, a method of folding the filament in the vacuum chamber (Method B) can be considered. Note that method A and method B may be combined.

  Below, arrangement | positioning of the filament in the vacuum chamber which concerns on 1st Embodiment is demonstrated, referring drawings. FIG. 2 is a view showing the arrangement of the filaments 1 in the vacuum chamber 30 according to the first embodiment. 2 is a view of the cat-CVD apparatus 100 as viewed from the B direction (above) in FIG. 1 described above.

  As shown in FIG. 2, a plurality of rollers 80 (rollers 80 </ b> A to 80 </ b> H) are arranged in the vacuum chamber 30. The filament 1 is stretched around each roller 80 and stretched in a zigzag manner in the vacuum chamber 30.

(Function of cat-CVD apparatus)
Hereinafter, the configuration of the cat-CVD apparatus according to the first embodiment will be described with reference to the drawings. FIG. 3 is a block diagram illustrating functions of the cat-CVD apparatus 100 according to the first embodiment.

  As shown in FIG. 3, the cat-CVD apparatus 100 includes an operation reception unit 110, a control unit 120, a heater 21, a take-up pinch roller 40, a heater 41, and a current supply source 70.

  The operation reception unit 110 receives an operation by a user. For example, the operation reception unit 110 receives an operation for starting the film formation.

  The control unit 120 controls the heating amount of the heater 21 and the heater 41. Specifically, the control unit 120 controls the heating amount of the heater 21 so that the temperature of the filament 1 stretched over the feed roller 20 is higher than the ductile-brittle transition temperature. The control unit 120 controls the heating amount of the heater 41 so that the temperature of the filament 1 sandwiched between the roller 40A and the roller 40B is higher than the ductile-brittle transition temperature.

  Here, it is desirable that the control unit 120 controls the heating amounts of the heater 21 and the heater 41 so that the temperature of the filament 1 is higher on the take-up pinch roller 40 side than on the feed roller 20 side.

  The control unit 120 controls the speed at which the filament 1 is taken up by the take-up pinch roller 40. Specifically, the control unit 120 takes up the take-up pinch roller 40 so that the filament 1 is taken up at a speed determined according to the material of the filament 1, the length from the connection point 71 to the connection point 72, and the film formation conditions. To control.

  The control unit 120 controls the amount of current that flows through the filament 1 between the connection point 71 and the connection point 72. Specifically, the control unit 120 controls the amount of current supplied by the current supply source 70 so that the temperature of the filament 1 becomes a temperature necessary for film formation.

  The current supply source 70 is connected to the current supply line 71 </ b> A and the current supply line 72 </ b> A described above, and causes a current to flow through the filament 1 between the connection point 71 and the connection point 72.

(Operation of cat-CVD apparatus)
Hereinafter, the operation of the cat-CVD apparatus according to the first embodiment will be described with reference to the drawings. FIG. 4 is a flowchart showing the operation of the cat-CVD apparatus 100 according to the first embodiment.

  As shown in FIG. 4, in step 10, the cat-CVD apparatus 100 uses a heater so that the temperature of the filament 1 sandwiched between the rollers 40 </ b> A and 40 </ b> B is higher than the ductile-brittle transition temperature. The amount of heating 41 is controlled.

  In step 20, the cat-CVD apparatus 100 controls the amount of current supplied by the current supply source 70 so that the temperature of the filament 1 becomes a temperature necessary for film formation.

  In step 30, the cat-CVD apparatus 100 controls the heating amount of the heater 21 so that the temperature of the filament 1 passed over the delivery roller 20 is higher than the ductile-brittle transition temperature. To do.

  Here, it should be noted that the cat-CVD apparatus 100 controls the heating amounts of the heater 21 and the heater 41 so that the temperature of the filament 1 is higher on the winding pinch roller 40 side than on the feeding roller 20 side. is there.

  Moreover, in order to suppress that the temperature of the filament 1 falls below the ductile-brittle transition temperature and the filament 1 breaks, it is preferable that the heating treatment of the filament 1 is performed in the order closer to the winding pinch roller 40 side. It should be noted. It should be noted that the processing from step 10 to step 30 may be performed simultaneously.

  In step 40, the cat-CVD apparatus 100 starts winding the filament 1 so that the filament 1 is wound at a speed determined according to the length from the connection point 71 to the connection point 72 and the film formation conditions.

  In step 50, the cat-CVD apparatus 100 supplies a source gas into the vacuum chamber 30, adjusts the pressure in the vacuum chamber 30, the temperature of the growth substrate 200, and the like to predetermined film formation conditions, and then grows the growth substrate 200. The process of forming a thin film on top is started.

  In step 60, the cat-CVD apparatus 100 cools the filament 1 taken up by the take-up pinch roller 40 by a method such as natural cooling, and then crushes the filament 1 by the crusher 61A and the crusher 61B. The filament 1 thus prepared is accommodated in the waste material container 60.

(Function and effect)
According to the cat-CVD apparatus 100 according to the first embodiment, the heater 41 heats the filament 1 on the winding pinch roller 40 side until the temperature becomes higher than the ductile-brittle transition temperature of the filament 1. Therefore, it is possible to reduce the breakage of the filament 1 in the vacuum chamber 30 due to the ductile-brittle transition caused by the temperature decrease of the filament 1 on the winding pinch roller 40 side. Therefore, even when a material having a high ductile-brittle transition temperature is used as the material of the filament 1, the filament 1 can be easily replaced in a vacuum.

  The heater 21 heats the filament 1 on the delivery roller 20 side until the temperature becomes higher than the ductile-brittle transition temperature of the filament 1. Therefore, the filament 1 can be further prevented from being broken in the vacuum chamber 30 due to the ductile-brittle transition caused by the temperature drop of the filament 1 on the delivery roller 20 side.

  The controller 120 controls the heating amounts of the heater 21 and the heater 41 so that the temperature of the filament 1 is higher on the winding pinch roller 40 side than on the feeding roller 20 side. That is, the heating amounts of the heater 21 and the heater 41 are controlled so that the temperature of the filament 1 that has become brittle due to the coarsening of the metal crystal is higher than the temperature of the filament 1 that has not been coarsened. . Therefore, breakage of the filament 1 in the vacuum chamber 30 due to the ductile-brittle transition can be efficiently suppressed.

  The winding pinch roller 40 winds the filament 1 in a state where a thin film is formed on the growth substrate 200, that is, in a state where a current flows through the filament 1 between the connection point 71 and the connection point 72. That is, since the filament 1 is exchanged while forming a thin film on the growth substrate 200, the manufacturing efficiency of an element having a thin film (such as a semiconductor element or a solar cell element) is improved.

[Other Embodiments]
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the embodiment described above, only the take-up pinch roller 40 has a drive source, but the present invention is not limited to this. Specifically, not only the take-up pinch roller 40 but also the delivery roller 20 may have a drive source.

  The heating method of the filament 1 in the region b may be, for example, heating by energizing the filament 1 in the region b instead of heating by the heater 21. The heating bobbin is provided on the winding side of the filament 1 and the crushing in step 60 may not be performed.

  In the embodiment described above, the filament 1 is gradually replaced during the film forming process, but the present invention is not limited to this. Specifically, the filament 1 may be exchanged while heating the filament 1 after interrupting the film forming process. Also in this case, according to the present invention, it is possible to avoid opening the vacuum chamber 30 to the atmosphere, and to reduce the dead time.

It is a block diagram which shows the structure of the cat-CVD apparatus 100 which concerns on 1st Embodiment. It is a figure which shows arrangement | positioning of the filament 1 in the vacuum chamber 30 which concerns on 1st Embodiment. It is a block diagram which shows the function of the cat-CVD apparatus 100 which concerns on 1st Embodiment. It is a flowchart which shows operation | movement of the cat-CVD apparatus 100 which concerns on 1st Embodiment. It is a figure which shows the ductile-brittle transition curve of steel (Fe). It is a figure which shows the ductile-brittle transition temperature of a typical high temperature metal material.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Filament, 10 ... Bobbin, 20 ... Delivery roller, 21 ... Heater, 30 ... Vacuum chamber, 31 ... Gas supply path, 32 ... Gas discharge path, 33. ..Pedestal part, 34 ... heater, 40 ... winding pinch roller, 41 ... heater, 60 ... waste material container, 61 ... crusher, 70 ... current supply source, 71 ... Connection point, 71A ... Current supply line, 72 ... Connection point, 72A ... Current supply line, 80 ... Roller, 100 ... cat-CVD apparatus, 110 ... Operation acceptance Part, 120 ... control part, 200 ... growth substrate

Claims (5)

A cat-CVD apparatus comprising: a vacuum chamber containing at least a growth substrate; and a filament disposed in the vacuum chamber,
A delivery section for delivering the filament into the vacuum chamber;
A winding unit for winding the filament from the vacuum chamber;
A cat-CVD apparatus comprising: a winding-side heating unit that heats the filament on the winding unit side until the filament reaches a temperature higher than the ductile-brittle transition temperature. A delivery side heating unit for heating the filament on the delivery unit side until a temperature higher than the ductile-brittle transition temperature of the filament;
A control unit for controlling the heating amount of the winding side heating unit and the delivery side heating unit,
2. The cat-CVD apparatus according to claim 1, wherein the control unit controls the heating amount so that the temperature of the filament is higher on the winding unit side than on the feeding unit side. In a cat-CVD apparatus comprising a vacuum chamber containing at least a growth substrate and a filament disposed in the vacuum chamber, a filament exchange method for exchanging the filament,
Delivering the filament into the vacuum chamber;
Winding the filament from within the vacuum chamber;
In the step of winding the filament, the filament is wound up while heating the filament until the temperature becomes higher than the ductile-brittle transition temperature of the filament. In the step of sending out the filament, the filament is sent out while heating the filament until the temperature becomes higher than the ductile-brittle transition temperature of the filament,
In the step of feeding out the filament and the step of winding up the filament, the filament is heated so that the temperature of the filament is higher on the side of winding the filament than on the side of feeding the filament. Item 4. The filament replacement method according to Item 3.   The filament replacement method according to claim 3, wherein an electric current is supplied to the filament in the step of feeding the filament and the step of winding the filament.

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