JP2011032568A - Film forming method and film forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film forming method having a higher productivity when forming a thin film according to a sputtering method. <P>SOLUTION: The film forming method of forming a thin film on a substrate by sputtering a target includes: a film forming process S3 for forming the thin film on the substrate; and a stand-by process S4 for cooling the target to a prescribed temperature after finishing the film-forming process S3, wherein, in the film-forming process S3 and the stand-by process S4, temperature of a target is controlled by using a first coolant and a second coolant of which the temperature is lower than that of the first coolant. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for forming a thin film by a sputtering method and a film forming apparatus.

  Conventionally, when an optical thin film such as an antireflection film, a half mirror, or an edge filter is manufactured, a vacuum deposition method has been mainly used from the viewpoints of easiness of the method and film formation speed. On the other hand, the sputtering method has many advantages such as automation, labor saving, applicability to a large area substrate, and high adhesion to the substrate, and has been widely applied in the recent coating field.

  In film formation using a sputtering method, in order to realize highly accurate film thickness control, the film formation speed is stabilized and the film formation time is controlled. Thereby, the reproducibility of the film thickness can be obtained without using a film thickness monitoring system such as a film thickness monitor, and the apparatus cost can be reduced.

In order to stabilize the film formation rate, for example, it is mentioned as a countermeasure that the film formation conditions such as the target temperature, the flow rate of the introduced gas, and the applied voltage are kept constant. In particular, the following method is disclosed as a method for controlling the target temperature.
In Patent Document 1, a flow rate and temperature of cooling water for cooling a target are adjusted while measuring a surface temperature of the target, and a thin film forming apparatus that opens a shutter and starts film formation when the target surface temperature becomes constant, and A thin film forming method is disclosed.
Patent Document 2 discloses a cooling method for reducing an increase in target temperature using a cooling medium of 0 ° C. or lower.

Japanese Patent Application Laid-Open No. 11-100600 JP-A-8-193264

  However, in the method described in Patent Document 1, it takes time until the temperature of the entire cooling water changes in the cooling water temperature adjustment stage. Furthermore, it takes time until the target surface temperature is stabilized due to the temperature change of the cooling water. As a result, there is a problem that it takes time until the shutter is opened, the film formation tact time becomes long, and the productivity is low.

  In the method described in Patent Document 2, the temperature of the cooling medium is too low, so that the target temperature during film formation is difficult to increase. For this reason, there is a problem that the film formation rate is slow, the time until the desired film thickness is reached is lengthened, and the productivity is also lowered.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a film forming method and a film forming apparatus with higher productivity when forming a thin film by a sputtering method.

  A first aspect of the present invention is a film forming method for forming a thin film on a substrate by sputtering a target, the film forming step for forming the thin film on the substrate, and after the film forming step, A standby step for cooling the target to a predetermined temperature, and in the film forming step and the standby step, the temperature of the target is adjusted using a first refrigerant and a second refrigerant having a temperature lower than that of the first refrigerant. It is characterized by that.

  According to the film forming method of the present invention, by using the first refrigerant and the second refrigerant having different temperatures, the target is adjusted to a desired temperature more rapidly in the film forming process and the standby process.

  The first refrigerant may be used in the film forming step, and the second refrigerant may be used in the standby step. In this case, temperature adjustment suitable for the state of the target and the set temperature can be performed.

  In the film forming step, the first refrigerant and the second refrigerant may be used, and in the standby step, only the second refrigerant may be used. Further, both the first refrigerant and the second refrigerant may be controlled to be −60 ° C. or higher and 300 ° C. or lower. In these cases, temperature adjustment suitable for the state of the target and the set temperature can be performed.

  According to a second aspect of the present invention, there is provided a film forming apparatus for sputtering a target to form a thin film on a substrate, wherein a target holding unit on which the target is installed, and a first coolant is heated to the target holding unit. A first cooling mechanism that cools the target by bringing them into contact with each other, and a second cooling mechanism that cools the target by bringing the second refrigerant having a temperature lower than that of the first refrigerant into thermal contact with the target holding portion. It is characterized by providing.

  According to the film forming apparatus of the present invention, by using the first cooling mechanism and the second cooling mechanism, the target is adjusted to a desired temperature more rapidly in the film forming process and the standby process.

  The first cooling mechanism may have a first flow path through which the first refrigerant is circulated and the second cooling mechanism may have a second flow path through which the second refrigerant is circulated. . In this case, the first refrigerant and the second refrigerant need not be mixed, and the refrigerant can be used repeatedly.

  The film forming apparatus of the present invention may further include a cooling channel through which the first refrigerant and the second refrigerant are circulated and a switching mechanism for switching between the refrigerant circulated and supplied to the cooling channel. . In this case, the degree of freedom of the arrangement of the cooling channel is increased, and the temperature of the target can be adjusted more efficiently.

  According to the film forming method and film forming apparatus of the present invention, it is possible to perform film formation by sputtering with higher productivity.

It is a figure which shows the structure of the film-forming apparatus of 1st Embodiment of this invention. It is a flowchart which shows the procedure of the film-forming method using the film-forming apparatus. It is a table | surface which shows the film-forming speed | rate of the Example using the same film-forming apparatus, and a comparative example. It is a graph which shows the temperature transition of the target in the 1st batch to the 3rd batch of the Example. It is a graph which shows the target temperature in the film-forming process in the Example, and immediately before a heating process. It is a graph which shows the temperature transition of the target in the 1st batch to the 3rd batch of the comparative example. It is a graph which shows the target temperature in the film-forming process in the comparative example, and immediately before a heating process. It is a table | surface which shows the film-forming speed | velocity | rate of the modification using the same film-forming apparatus. It is a graph which shows the target temperature in the film-forming process in the modification, and immediately before a heating process. It is a figure which shows the structure of the film-forming apparatus of 2nd Embodiment of this invention. It is a table | surface which shows the film-forming speed | velocity of the Example using the film-forming apparatus. It is a graph which shows the target temperature in the film-forming process in the Example, and immediately before a heating process.

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing the configuration of the film forming apparatus of this embodiment.
The film forming apparatus 1 of this embodiment includes a vacuum chamber 2 serving as a film forming chamber, a target holding unit 3 provided in the vacuum layer 2, a cooling unit 4 for cooling the target, and a vacuum layer 2. A gas introduction unit 5 for introducing gas and a control unit 6 for controlling the entire film forming apparatus 1 are provided.

The target holding unit 3 includes a dish 7 on which the target 100 is placed and a magnetron cathode 8 on which the dish 7 is placed. As the plate 7, various known materials such as quartz can be used. The magnetron cathode 8 has a diameter of 6 inches (about 150 millimeters (mm)), but is not limited thereto. The magnetron cathode 8 is connected to a high frequency power supply 9 and generates plasma to heat the target 100 to a predetermined temperature.
In the present embodiment, MgF ₂ granules having a particle size of 0.1 to 10 mm are used as the target 100.

  A substrate 101 to be deposited is rotatably attached above the target 100 in the vacuum chamber 2. A shutter 10 is installed between the substrate 101 and the target 100 so as to be retractable.

The cooling unit 4 includes a first cooling mechanism 11 and a second cooling mechanism 12 each having a supply unit that supplies a refrigerant and a flow path through which the refrigerant passes.
The first supply unit 13 of the first cooling mechanism 11 stores water (first refrigerant) whose temperature is controlled to 25 ° C., and allows water to flow to the lower part of the target 100 through the first flow path 14. it can. The second supply unit 15 of the second cooling mechanism 12 stores ethylene glycol (second refrigerant) whose temperature is controlled to minus 10 ° C. (−10 ° C.), and similarly via the second flow path 16. Thus, ethylene glycol can be allowed to flow under the target 100.

  Each flow path 14, 16 independently enters the vacuum layer 2, contacts the target holding unit 3 through the lower part of the target 100, comes out of the vacuum chamber 2 again, and then supplies each supply unit 13, 15. Configured to return. In addition, valves 17 and 18 for controlling the flow of each refrigerant are provided in each flow path 14 and 16. Various known valves can be used as the valves 17 and 18, but an electromagnetic valve or the like is preferable because automatic control by the control unit 6 is possible.

  The gas introduction unit 5 includes a mass flow controller 19 and controls a gas pressure in the vacuum chamber 2 by introducing a discharge gas such as oxygen from the introduction port 20 provided in the vacuum chamber 2 into the vacuum chamber 2. To do.

  The high frequency power source 9, the shutter 10, and the mass flow controller 19 are connected to the control unit 6, and these operations are automatically controlled by the control unit 6. In addition to these, the valves 17 and 18 may be connected to the control unit 6 as described above.

  The procedure of film formation by the film forming apparatus 1 configured as described above will be described below. FIG. 2 is a flowchart showing the procedure of the film forming method of the present embodiment. This method includes a preparation step S1 for placing the substrate 101 in the vacuum chamber 2, a heating step S2 for heating the target 100, a deposition step S3 for depositing a film on the substrate 101 by sputtering, and a target after deposition. A standby step S4 for cooling to a predetermined temperature.

  First, in the preparatory process of step S <b> 1, the substrate 101 is placed in the vacuum chamber 2. Then, the discharge gas is introduced into the vacuum chamber 2 from the introduction port 20 while the flow rate is controlled by the mass flow controller 19, and the inside of the vacuum chamber 2 is adjusted to a desired gas pressure.

  Next, in the heating process of step S <b> 2, electric power is supplied from the high frequency power supply 9 to the magnetron cathode 8. As a result, plasma 21 is generated in the vacuum chamber 2 and the target 100 is heated.

  Next, in the film forming process of step S3, the target 100 is sputtered by the discharge gas ions in the plasma 21. First, pre-sputtering is performed for a predetermined time in a state where the shutter 10 is disposed between the target 100 and the substrate 101, and then the film is formed on the substrate 101 after the shutter 10 is retracted. During this process, the valve 17 is open and the valve 18 is closed, so that water stored in the first supply unit 13 circulates through the first flow path 14 and is in thermal contact with the target holding unit 3. To adjust the temperature of the target 100.

  Subsequently, in the standby process of step S4, the shutter 10 moves again between the target 100 and the substrate 101, and the film formation is completed. Then, the valve 17 is closed, the valve 18 is opened, and the ethylene glycol stored in the second supply unit 15 circulates through the second flow path 16 and comes into thermal contact with the target holding unit 3 more rapidly. The target 100 is cooled and preparation for the next film formation is performed.

The film forming procedure described above will be further described using examples and comparative examples.
Example 1
As the substrate 101, an optical element made of optical glass S-BSL7 (refractive index 1.52, manufactured by OHARA INC.) Was used and installed in the vacuum chamber 2. Thereafter, the inside of the vacuum chamber 2 was evacuated to 1 × 10 ⁻⁴ Pascal (Pa) by a vacuum pump (not shown). At this time, the substrate 101 was not heated.
Next, O ₂ gas as discharge gas was introduced into the vacuum chamber 2 while controlling the flow rate by the mass flow controller 19, and the gas pressure was adjusted to 4 × 10 ⁻¹ Pa.

Next, high frequency power of 1000 W was supplied from the high frequency power source 9 to the magnetron cathode 8 to generate plasma 21 and to heat MgF ₂ as the target 100.

  Thereafter, pre-sputtering was performed for 3 minutes with the shutter 10 closed, and then the shutter 10 was retracted, film formation was performed for 1 minute, and the shutter 10 was closed again to complete film formation. Only the valve 17 was opened during the film forming process, and the temperature of the target 100 was adjusted by the first cooling mechanism 11.

In the standby step after film formation, the valve 17 was closed, the valve 18 was opened, and ethylene glycol at −10 ° C. was circulated for 5 minutes by the second cooling mechanism 12. Thereafter, the valve 18 was closed, the valve 17 was opened, and the next film formation was performed. These series of operations were automatically performed by the control unit 6.
The above film forming operation was repeated 10 times (10 batches).

(Comparative Example 1)
In Comparative Example 1, 10 batches of film formation were similarly performed using water at 25 ° C. as a refrigerant in both the film formation step and the standby step. Conditions other than the refrigerant used were the same as in Example 1.

FIG. 3 is a table showing the deposition rate of each batch in Example 1 and Comparative Example 1. The film formation rate was calculated from the film thickness of the produced MgF _{2 and} the film formation time. As shown in FIG. 3, in Example 1, there is no difference in the deposition rate of each batch and it is stable. On the other hand, it can be seen that in Comparative Example 1, as the batch progresses, the deposition rate gradually increases and is not stable.

  FIG. 4 is a graph showing the transition of the target temperature in the heating process, the film forming process, and the standby process in the first to third batches of Example 1. As shown in FIG. 4, even when repeated film formation is performed, the target temperature rapidly decreases during the 5-minute standby process, and the target temperature at the start of the heating process of each batch becomes equal in each film formation batch. Yes. Moreover, the target temperature during the film forming process was also equal. As shown in FIG. 5, the target temperature during the film forming process and immediately before the heating process was stable up to the 10th batch.

FIG. 6 is a graph showing the transition of the target temperature in the heating process, the film forming process, and the standby process in the first to third batches of Comparative Example 1. As shown in FIG. 6, in Comparative Example 1, when repeated film formation is performed, the target temperature does not fall to the temperature at the start of the heating process of the first batch during the 5-minute standby process, and the target temperature at the start of the heating process is not increased. The temperature was different for each batch. For this reason, the target temperature during the film formation process varies from batch to batch even though the heating conditions of the target are the same, and as a result, the film formation rate gradually increases as the film formation is repeated. This tendency became more prominent as the number of film formations increased as shown in FIG.
Further, in Comparative Example 1, when the time required for the target temperature after the film forming process to be lowered to the temperature at the start of the heating process of the first batch was measured, a waiting time of about 10 to 20 minutes was required.

  According to the film forming apparatus 1 of the present embodiment, the first cooling mechanism 11 and the second cooling mechanism 12 that circulate refrigerants having different temperatures are provided, and the temperature of the target 100 during the film forming process is relatively controlled. The target 100 is cooled by water, which is a high-temperature first refrigerant, and the target 100 is rapidly cooled by ethylene glycol, which is a relatively low-temperature second refrigerant, after the film formation process is completed (during the standby process). . Therefore, even if the film formation is repeated many times, the temperature of the target at the start of the heating process and during the film formation process is kept constant, so that the film formation speed can be stabilized and always good film formation can be performed. .

  Moreover, in the film-forming process S3 in which the target 100 is heated, a relatively high temperature first refrigerant is used, and in the standby process S4 in which the target 100 is cooled, a relatively low temperature second refrigerant is used. Therefore, the target 100 can be adjusted to a desired temperature more rapidly in any process. Accordingly, the time until the temperature of the target 100 is stabilized is shortened, and the time required for the total film forming operation can be shortened to improve the efficiency of the film forming operation.

  Furthermore, since the target 100 is cooled by circulating the first refrigerant and the second refrigerant through different flow paths 14 and 16, respectively, the refrigerant is not mixed and each refrigerant is repeatedly used. can do. Further, since the refrigerant does not cause a chemical reaction, safety can be improved.

  Next, Modification 1 of the present embodiment will be described with reference to FIGS. 8 and 9. The difference between the present modification and the first embodiment described above is the operation mode of the first refrigerant to be used and each cooling mechanism.

(Modification 1)
In the first modification, oil controlled at 250 ° C. is used as the first refrigerant stored in the first supply unit 13. The second refrigerant stored in the second supply unit 15 was ethylene glycol (−10 ° C.) as in Example 1.
The target 100 and the substrate 101 were the same as those in Example 1, and the gas pressure was adjusted and the target 100 was heated by the same method as in Example 1.

Thereafter, pre-sputtering was performed for 3 minutes with the shutter 10 closed, and then the shutter 10 was retracted, film formation was performed for 1 minute, and the shutter 10 was closed again to complete film formation.
During the film forming process, the valves 17 and 18 were opened, and the first refrigerant and the second refrigerant were circulated and supplied to the first flow path 14 and the second flow path 16, respectively. As a result, the average temperature under the target 100 was controlled to 150 ° C.

In the standby process after the film formation, the valve 17 was closed and the circulation of oil as the first refrigerant was stopped. The valve 18 was left open, and ethylene glycol as the second refrigerant was circulated through the second flow path 16 for 5 minutes. Thereafter, the valve 17 was opened again and oil was circulated through the first flow path 14 to execute the next film formation.
The above film forming operation was repeated 10 times (10 batches).

  FIG. 8 is a table showing the deposition rate of each batch of the first modification. As shown in FIG. 8, in the first modification, the deposition rate of each batch is stable with no difference.

FIG. 9 is a graph showing the target temperature during the film forming process of each batch and immediately before the heating process in Modification 1. In Modification 1, the target temperature during the film forming process was controlled at almost the same value in all batches. In addition, the target temperature was sufficiently lowered during the standby process, and the target temperature at the start of the heating process and during the film formation process was controlled equally even when the film formation was repeated. Thus, it is considered that the film formation rate was stabilized because the temperature of the target was suitably controlled.
In the first modification, the target cooling temperature is controlled to be higher than that in the first embodiment. Therefore, the target temperature in the film forming process is higher in the first modification. For this reason, when a power output equal to that of the embodiment is applied, the film forming speed is faster in Modification 1.
In the first modification, the valve 17 is closed and the circulation of oil as the first refrigerant is stopped in the standby process, but the valves 17 and 18 are both opened, and the first flow path 14 and the second flow path 16 are opened. Each of the first refrigerant and the second refrigerant may be circulated and supplied. However, in this case, the flow rate of the first refrigerant needs to be sufficiently reduced as compared with the film forming step.

  Next, a film forming apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The difference between the film forming apparatus 31 of the present embodiment and the film forming apparatus 1 of the first embodiment described above is that the first refrigerant and the second refrigerant circulate through a common flow path. In addition, about the structure which is common in the above-mentioned 1st Embodiment, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  FIG. 10 is a diagram showing the configuration of the film forming apparatus 31. In the film forming apparatus 31, the first supply unit 13 and the second supply unit 15 are connected to a common cooling channel 32. A first supply valve 33 and a second supply valve 34 are provided between the upstream side of the cooling flow path 32 and the supply units 13 and 15, respectively, so that the refrigerant circulated through the cooling flow path 32 can be switched. It has become. Similarly, a first recovery valve 35 and a second recovery valve 36 are provided between the downstream side of the cooling flow path 32 and the supply units 13 and 15, respectively. Each of the valves 33, 34, 35, and 36 described above functions as a switching mechanism that switches the refrigerant circulated and supplied to the cooling flow path 32.

An example of film formation using the film formation apparatus 31 configured as described above will be described below as Example 2.
(Example 2)
As the 1st refrigerant and the 2nd refrigerant, the same thing as Example 1 was stored in the 1st supply part 13 and the 2nd supply part 15, respectively. And the target 100 and the board | substrate 101 used the same thing as Example 1. FIG. Gas pressure adjustment and target heating were performed in the same manner as in Example 1.

Thereafter, pre-sputtering was performed for 3 minutes with the shutter 10 closed, and then the shutter 10 was retracted, film formation was performed for 1 minute, and the shutter 10 was closed again to complete film formation.
During the film forming step, the first supply valve 33 and the first recovery valve 35 were opened, and 25 ° C. water as the first refrigerant was circulated and supplied to the cooling flow path 32. At this time, the second supply valve 34 and the second recovery valve 36 were closed, and the supply of −10 ° C. ethylene glycol as the second refrigerant was stopped.

  After completion of the film forming process, air was supplied to the cooling flow path 32 from an air supply device (not shown), and the first refrigerant remaining in the cooling flow path 32 was discharged out of the cooling flow path 32 through a waste flow path (not shown). Thereafter, in the standby step, the second supply valve 34 and the second recovery valve 36 were opened, and the second refrigerant was circulated and supplied to the cooling flow path 32 for 4 minutes. Thereafter, the second supply valve 34 and the second recovery valve 36 were closed, and the second refrigerant remaining in the cooling flow path 32 was discharged using the air supply device in the same manner as the first refrigerant. After the second refrigerant was discharged, the first supply valve 33 and the first recovery valve 35 were opened, the first refrigerant was supplied to the cooling flow path 32, and the next film formation was performed. In this way, 10 batches of film were formed.

FIG. 11 is a table showing the deposition rate of each batch in Example 2. In Example 2, there was no difference in the deposition rate of each batch and it was stable.
FIG. 12 is a graph showing the target temperature during the film forming process and immediately before the heating process of each batch in Example 2. In Example 2, in all batches, the target temperature during the film forming process was controlled with high accuracy at a substantially equal value. Further, the target temperature was sufficiently lowered during the standby process for 4 minutes, and even when the film formation was repeated, the target temperature at the start of the heating process and during the film formation process was controlled equally in each batch. Thus, it was considered that the film formation rate was stabilized because the temperature of the target 100 was suitably controlled.

  According to the film forming apparatus 31 of this embodiment, since only one system of the cooling flow path 32 is formed below the target 100, there is a sufficient space for the flow path. Therefore, a flow path optimal for temperature control of the target 100 can be formed, and the cooling time of the target 100 can be further shortened. In addition, since it is not necessary to dispose a plurality of channels in the lower part of the target 100, the apparatus can be configured at a lower cost.

  As mentioned above, although each embodiment of this invention was described, the technical scope of this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

  For example, in each of the above-described embodiments, an example in which water, oil, and ethylene glycol are used as the first refrigerant and the second refrigerant has been described. However, the refrigerant that is used is not limited thereto, and air, nitrogen A gas such as a gas, a liquefied gas such as liquid nitrogen or liquid helium, a hydrocarbon, a fluorinated hydrocarbon, an alcohol, high-pressure water, high-pressure steam, a liquid metal, or the like may be used. By using what is appropriately selected from these as the first refrigerant and the second refrigerant, it is possible to set the target temperature to an arbitrary value.

  However, if the temperature of the refrigerant is higher than 500 ° C, the heat limit of members such as packing and piping installed around the target and the device may be exceeded and leakage may occur, so the temperature of the refrigerant is set to 500 ° C or less. Preferably it is done. Therefore, the temperature of the relatively high temperature first refrigerant is preferably set to 0 ° C. or more and 500 ° C. or less, and the temperature of the relatively low temperature second refrigerant is preferably set to −273 ° C. or more. It is also possible to use liquid helium at −270 ° C. However, practically, both the first refrigerant and the second refrigerant are more preferably used in the range of −60 ° C. or more and 300 ° C. or less for reasons such as device cost and pipe type selectivity.

Moreover, in each above-mentioned embodiment, although the example using two types of refrigerant | coolants of a 1st refrigerant | coolant and a 2nd refrigerant | coolant was demonstrated, three or more types of refrigerant | coolants may be used. Furthermore, the shape and arrangement of the refrigerant flow path for target cooling may be set as appropriate in consideration of cooling efficiency and the like.
Moreover, you may start flowing a refrigerant | coolant from a heating process. In this case, it is preferable that the high frequency power is set higher than that in the film forming step so that the temperature is easily increased.

  Further, in the above-described embodiment, the example in which the refrigerant remaining in the cooling flow path is discarded has been described. Instead, the air is supplied to the cooling flow path to collect the refrigerant in each supply unit. A film forming apparatus may be configured as described above.

DESCRIPTION OF SYMBOLS 1, 31 Film-forming apparatus 3 Target holding part 11 1st cooling mechanism 12 2nd cooling mechanism 14 1st flow path 16 2nd flow path 32 Cooling flow path S3 Film-forming process S4 Standby process

Claims (7)

A film forming method for forming a thin film on a substrate by sputtering a target,
A film forming step of forming the thin film on the substrate;
A standby step for cooling the target to a predetermined temperature after the film formation step is completed;
With
In the film forming step and the standby step, the temperature of the target is adjusted using a first refrigerant and a second refrigerant having a temperature lower than that of the first refrigerant.   The film forming method according to claim 1, wherein the first refrigerant is used in the film forming step, and the second refrigerant is used in the standby step.   2. The film forming method according to claim 1, wherein the first refrigerant and the second refrigerant are used in the film forming step, and only the second refrigerant is used in the standby step.   4. The film forming method according to claim 1, wherein each of the first refrigerant and the second refrigerant is controlled to be −60 ° C. or more and 300 ° C. or less. 5. A film forming apparatus for forming a thin film on a substrate by sputtering a target,
A target holding unit on which the target is installed;
A first cooling mechanism that cools the target by bringing the first refrigerant into thermal contact with the target holding unit;
A second cooling mechanism that cools the target by bringing a second refrigerant having a temperature lower than that of the first refrigerant into thermal contact with the target holding unit;
A film forming apparatus comprising: The first cooling mechanism has a first flow path through which the first refrigerant is circulated,
The film forming apparatus according to claim 5, wherein the second cooling mechanism includes a second flow path through which the second refrigerant is circulated. A cooling flow path through which the first refrigerant and the second refrigerant are circulated and supplied;
A switching mechanism for switching the refrigerant circulated and supplied to the cooling flow path;
The film forming apparatus according to claim 5, further comprising:

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