JP2009200142A - Film forming device and film forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film forming device and an efficient film forming method capable of efficiently conducting the film forming process. <P>SOLUTION: The film forming device 1 provides a film forming process to a substrate mounted in a film forming chamber 2. A substrate standby part 4 is connected to the film forming chamber 2 through a first opening and closing part 3, and includes a robot 17 for transferring the substrate-susceptor for automatically transferring the susceptor with a plurality of substrates mounted between the substrate standby part 4 and the film forming chamber 2. A cleaning part 5 for cleaning the susceptor after film forming is provided in the outside of the film forming chamber 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a film forming apparatus and a film forming method.

  Conventionally, a substrate is processed under a pressure or atmosphere different from the atmosphere, such as low pressure epitaxial vapor deposition. For example, Patent Document 1 discloses a multi-chamber type single wafer processing apparatus including an inlet / outlet port having a gate that can be opened and closed on the atmosphere side, a platform connected to the inlet / outlet port, and a plurality of processing chambers connected to the platform. It is disclosed.

  In the apparatus of Patent Document 1, the gate of the entrance / exit port is opened while the substrate is being processed in the processing chamber, and the processed substrate and the unprocessed substrate are transferred. The gate is then closed and the gate or gate between them is opened after the pressure or atmosphere in the inlet / outlet port is the same as the pressure or atmosphere in the platform. Then, after the processing of any one of the processing chambers is finished, the gate connecting the processing chamber and the platform is opened, and the processed substrate in the processing chamber and the unprocessed substrate in the inlet / outlet port are connected. Delivery takes place.

JP-A-5-55148

  However, in the conventional single wafer type film forming apparatus, the substrates are carried into the processing chamber one by one, and the film forming process is performed on each substrate. For example, in the apparatus of Patent Document 1, after a single substrate is loaded into the entrance / exit port, the substrate is loaded into the processing chamber via the platform. In the processing chamber, a film forming process is performed on one loaded substrate. After the processing is completed, the substrate is taken out from the processing chamber and transferred to the entrance / exit port through the platform. On the other hand, another substrate is carried into the processing chamber, and a film forming process is performed on this substrate. Therefore, even if the substrate can be transferred between the entrance / exit port and the outside during processing in each processing chamber, only one substrate at a time is processed in the processing chamber, so that the operating rate of the apparatus is sufficiently improved. I could not.

  Further, in the processing in the processing chamber, a film is formed not only on the substrate but also on the surface of the susceptor supporting the substrate. When this film is peeled off, it becomes dust and causes defects in the film formed on the substrate. Therefore, it is necessary to periodically wash the susceptor to remove the film. Therefore, conventionally, when the film formed on the susceptor reaches a predetermined thickness, the film forming process is stopped, and the film on the susceptor is removed by etching in the processing chamber. Such an operation has to be performed every time the susceptor is cleaned, which causes a reduction in the efficiency of the film forming process in the processing chamber.

  In particular, in the field of power electronics technology, a thick film of 10 μm or more is required as an epitaxial film for high voltage elements. For example, in order to obtain a withstand voltage of 30 kV, it is necessary to be an epitaxial film having a thickness of 200 μm or more. When a film having such a thickness is formed, the film formed on the surface of the susceptor also becomes thick. For this reason, cleaning of the susceptor has to be performed frequently, and the reduction in the efficiency of the film forming process has become serious.

  The present invention has been made in view of these problems. That is, an object of the present invention is to provide a film forming apparatus capable of performing a film forming process efficiently.

  Another object of the present invention is to provide an efficient film forming method.

  Other objects and advantages of the present invention will become apparent from the following description.

A first aspect of the present invention is a film forming apparatus for performing a film forming process on a substrate placed in a film forming chamber,
A substrate standby unit connected to the film formation chamber via an opening / closing unit;
A transfer means for automatically transferring a susceptor on which a plurality of substrates are placed between the substrate standby section and the film forming chamber;
A cleaning unit provided outside the film forming chamber for cleaning the susceptor after the film forming process is completed;
The substrate standby section is provided with a heating means for heating the susceptor carried out of the film forming chamber and the substrate.

  1st aspect of this invention WHEREIN: The said heating means can heat the part in which the said susceptor of the said conveyance means is mounted.

  In a second aspect of the present invention, a susceptor on which a plurality of substrates are placed is automatically transferred into a film formation chamber, and after the film formation process is simultaneously performed on the plurality of substrates, The substrate and the susceptor are transported to a substrate standby unit connected via an opening / closing unit, and then a film attached to the surface of the susceptor is removed by a cleaning unit provided outside the film formation chamber. To do.

  In the second aspect of the present invention, the substrate standby part is provided with a heating means, and when the heating means is operated and the film formation chamber and the substrate standby part have a predetermined temperature difference, the opening and closing is performed. The substrate and the susceptor can be transferred from the film forming chamber to the substrate standby unit.

  In the second aspect of the present invention, while the film forming process is being performed, a plurality of other substrates are placed on and put into another susceptor cleaned by the cleaning unit in the substrate standby unit. A new film formation process can be performed in the film formation chamber instead of the substrate and the susceptor after the film process.

  According to the first aspect of the present invention, the transfer means for automatically transferring the susceptor on which the plurality of substrates are placed between the substrate standby section and the film forming chamber is provided. At the same time, film formation can be performed. In addition, since the cleaning unit for cleaning the susceptor after the film formation process is provided outside the film formation chamber, it is not necessary to interrupt the film formation process every time the susceptor is cleaned. Further, since the substrate standby section is provided with a susceptor carried out of the film formation chamber and a heating means for heating the substrate, the opening and closing section is opened with the temperature in the film formation chamber being relatively high, so that the substrate and the susceptor Can be removed from the film formation chamber.

  According to the second aspect of the present invention, since the film forming process is simultaneously performed on a plurality of substrates, the film can be formed more efficiently than the method of processing the substrates one by one.

  FIG. 1 is a schematic plan view of a film forming apparatus in the present embodiment.

  As shown in FIG. 1, the film forming apparatus 1 is connected to the film forming chamber 2 through a film forming chamber 2 for forming a film on the surface of the substrate placed on the susceptor and a first opening / closing part 3. A substrate standby unit 4 and a cleaning unit 5 for cleaning the susceptor taken out from the film forming chamber 2 through the substrate standby unit 4 are provided. Here, the first opening / closing part 3 corresponds to an “opening / closing part” in the film forming apparatus of the present invention. In the film forming chamber 2, for example, a reactive gas is introduced to form an epitaxial film on the surface of the substrate. Further, a film may be formed on the substrate by vapor deposition or sputtering.

  One of the features of the film forming apparatus 1 is that a plurality of substrates are carried into the film forming chamber 2 and film forming processes are simultaneously performed on these substrates. That is, in the present invention, film formation is performed by combining single wafer processing and batch processing. As a result, the processing that has been performed one by one in the conventional single-wafer type film forming apparatus can be performed multiple times, so that the operating rate of the film forming apparatus 1 can be improved.

  Another feature of the film forming apparatus 1 is that a substrate standby unit 4 connected to the film forming chamber 2 is provided. The substrate standby unit 4 is provided with a heating means for heating the susceptor carried out of the film formation chamber 2 and the substrate, so that the first opening / closing unit 3 can be opened while the temperature in the film formation chamber 2 is relatively high. The substrate and the susceptor can be removed from the film formation chamber 2 by opening. That is, since it is not necessary to wait for the temperature in the film formation chamber 2 to drop sufficiently, the operating rate of the film formation apparatus 1 can be improved and the efficiency of the film formation process can be increased.

  Another feature of the film forming apparatus 1 is that the susceptor is unloaded from the film forming chamber 2 and cleaned by the cleaning unit 5. Thereby, it is not necessary to interrupt the film forming process every time the susceptor is cleaned, and the efficiency of the film forming process can be improved.

  In the present embodiment, the susceptor is carried out of the film formation chamber 2 together with the substrate every time one film formation process is completed. It is also possible to carry out only the substrate up to a predetermined number of times, and unload the susceptor together with the substrate when the predetermined number of times has been reached. The timing for unloading the susceptor is preferably determined by the thickness of the film formed on the surface of the susceptor. For example, when the thickness of the film deposited on the susceptor reaches 100 μm, the film can be taken out together with the substrate and the susceptor can be cleaned. According to the present invention, no matter what timing the susceptor is unloaded, the efficiency of the film forming process is hardly affected. Therefore, for example, when a thick film of 10 μm or more is formed on a substrate in the field of power semiconductors and the like, the susceptor can be cleaned without greatly reducing the efficiency of the film forming process.

  Next, the operation of the film forming apparatus 1 and the film forming method according to the present invention will be described in detail with reference to FIGS.

  The susceptor S that supports the substrate in the film forming chamber 2 is housed in the susceptor standby chamber 6. The susceptor S in the susceptor standby chamber 6 is cleaned by the cleaning unit 5 provided outside the film forming chamber 2. When the film formation process is performed, the susceptor S is taken out of the susceptor standby chamber 6 by the susceptor transfer robot 7 and placed on the substrate-susceptor placement unit 8.

  On the other hand, the substrate W on which the film forming process is performed is stored in the cassette 9. When film formation is performed, the substrate transfer robot 10 takes out the substrate W from the cassette 9 and places it on the susceptor S in the substrate-susceptor mounting portion 8. Here, for transporting the substrate W, for example, a Bernoulli chuck or the like that can transport the substrate in a non-contact state by ejecting gas can be employed. Examples of the substrate W include a 300 mm silicon wafer used for applications such as a power semiconductor.

  The substrate-susceptor placement unit 8 is connected to the substrate standby unit 4 via the second opening / closing unit 11. Further, by opening the third opening / closing part 12 or the fourth opening / closing part 22, the substrate W and the susceptor S can be carried into and out of the substrate-susceptor mounting part 8 from the outside. Therefore, when the above-described substrate W and susceptor S are placed in the substrate-susceptor placement portion 8, the third opening / closing portion 12 or the fourth opening / closing portion 22 with the second opening / closing portion 11 closed. Are opened, and these are carried into the substrate-susceptor mounting portion 8. By providing the substrate-susceptor standby unit 8, it is possible to prevent external air from directly entering the film forming chamber 2. That is, it is possible to prevent moisture and organic substances in the air from entering the film forming chamber 2 and adversely affecting the film forming process. Note that only one of the third opening / closing portion 12 and the fourth opening / closing portion 22 may be provided, and the substrate W and the susceptor S may be carried in / out through a common opening / closing portion.

A plurality of susceptors on which a plurality of substrates are placed can be put into the film forming apparatus 1. In this embodiment, the susceptor S ₁ of the substrate W ₁ is placed, the susceptor S ₂ of the substrate W ₂ is placed, the susceptor S ₃ of the substrate W ₃ is placed is on. Specifically, as shown in FIG. 1, the susceptor S ₁ is loaded into the substrate-susceptor mounting portion 8, the susceptor S ₂ is loaded into the substrate standby portion 4, and the susceptor S ₃ is loaded into the film forming chamber 2. Here, the substrate W ₁ is a substrate film formation untreated substrate W ₂ is the deposition processed substrate, the substrate W ₃ being a substrate during film formation. The following description focuses on the substrate _{W 1} and the susceptor _{S 1.}

The susceptor in this embodiment has a structure on which a plurality of substrates can be placed. For example, the susceptor S shown in FIG. 1 is provided with four substrate placement portions _Sws for placing the substrate W, and four substrates W can be placed simultaneously. Four substrates W _{1 to} W ₃ are placed on each of the susceptors S _{1 to} S ₃ . With the susceptor having such a structure, four substrates can be simultaneously loaded into the substrate-susceptor mounting portion 8.

The number of substrates that can be placed on the susceptor, that is, the number of substrate platforms _Sws , can be appropriately determined according to the size of the substrate. Further, it is determined also from the viewpoint of the film thickness uniformity of the film formed in the film forming chamber 2 and the efficiency of the film forming process. If the number of substrates placed in the film formation chamber 2 is increased by increasing the number of substrate platforms _Sws, the film thickness uniformity of the film formed on the substrate is lowered. On the other hand, if the number of the substrate placement units _Sws is too small, it is not possible to carry the substrate into the film forming chamber 2 so much that the efficiency of the film forming process is lowered. In the case of a 300 mm silicon wafer, the number of substrate platforms _Sws is preferably 10 or less, and more preferably about 4 to 5.

After the susceptor S ₁ on which the substrate W ₁ is placed is carried into the substrate-susceptor placement unit 8, the third opening / closing unit 12 and the fourth opening / closing unit 22 are closed. And the air in the board | substrate-susceptor mounting part 8 is discharged | emitted from the exhaust port 13 using a vacuum pump. Next, nitrogen gas is introduced into the substrate-susceptor mounting portion 8 through the inlet 14. Argon gas or the like may be introduced instead of nitrogen gas.

  The substrate standby unit 4 is also provided with an introduction port 15 and an exhaust port 16. The introduction port 15 is connected to a cylinder containing nitrogen gas through a pipe (not shown) so that the nitrogen gas can be introduced into the substrate standby unit 4. Further, the exhaust port 16 is connected to a vacuum pump (not shown) through a pipe (not shown) so that the gas in the substrate standby section 4 is discharged from here.

  The substrate standby unit 4 is provided with a substrate-susceptor transfer robot 17 which is a transfer means of the present invention. The substrate-susceptor transfer robot 17 is made of, for example, a heat-resistant material in which carbon is silicon-coated. Further, a heater on which the susceptor of the substrate-susceptor transfer robot 17 is placed is provided with a heater which is a heating means of the present invention, and a high-temperature susceptor or substrate immediately after being taken out from the film forming chamber 2 is provided. Even if it is placed, it has a structure that does not cause a rapid temperature change.

  FIG. 2 is an enlarged plan view of a portion where the susceptor of the substrate-susceptor transfer robot 17 is placed in the present embodiment. In FIG. 2, the susceptor arrangement portion 17a is a rectangular plate-shaped member. As shown in FIGS. 1 and 2, a rotating member 17b is connected to the susceptor arrangement portion 17a, and is configured to be extendable and contractable so that the distance from the fulcrum portion 17c to the susceptor arrangement portion 17a can be adjusted. The susceptor arrangement portion 17a is provided with a heater 17d inside the plate member. The heater 17d has a tape-like structure in which a heating wire is covered with a flexible heat-resistant resin. The heater 17d generates heat by passing a current through the heating wire, and the temperature of the susceptor arrangement portion 17a can be adjusted. Yes.

  The heating means may be a lamp instead of the heater. However, the temperature can be adjusted. The heating temperature can be, for example, 25 ° C to 800 ° C. The substrate-susceptor transfer robot 17 is preferably provided with a cooling mechanism for the purpose of preventing thermal damage to the rotation mechanism and the like.

  The heating means in this embodiment may be any means that heats the susceptor and the substrate carried out from the film formation chamber 2. Therefore, the board | substrate standby part 4 is not restricted to said structure, It is also possible to make it the structure which heats the whole board | substrate standby part 4 from the outer side. However, in consideration of thermal damage given to the substrate-susceptor transfer robot 17, it is preferable to have a structure in which only the portion where the susceptor is placed is heated.

After the susceptor S ₁ on which the substrate W ₁ is placed is carried into the substrate-susceptor placement unit 8, the pressure and atmosphere in the substrate-susceptor placement unit 8 become substantially equal to those in the substrate standby unit 4. 2 open / close part 11 is opened. Here, in the substrate-susceptor mounting portion 8, the members supporting the lower surface of the peripheral edge of the substrate are arranged in parallel in two upper and lower stages, so that the susceptor S ₁ and the susceptor S ₂ can be exchanged smoothly. It can be carried out. Specifically, first, a substrate - by the susceptor transfer robot 17, a susceptor S ₂ of the substrate W ₂ is placed, the substrate - mounting on a member located in the lower part and carried into the susceptor mounting unit 8 Put. Next, the substrate-susceptor transport robot 17 carries the susceptor S ₁ placed on the upper member together with the substrate W ₁ into the substrate standby unit 4.

When the processing in the film forming chamber 2 is completed, the first opening / closing unit 3 is opened, and the substrate-susceptor transport robot 17 transports the susceptor S ₃ on which the substrate W ₃ is placed into the substrate standby unit 4. . In this case, the substrate - by previously raising the temperature of a portion susceptor S ₃ is placed in a heater at a susceptor transfer robot 17, a rapid temperature change applied to the substrate W ₃ and susceptor S ₃ be hot Can be prevented. Next, the substrate-susceptor transfer robot 17 carries the susceptor S ₁ on which the substrate W ₁ is placed into the film forming chamber 2.

  The film forming chamber 2 is also provided with an introduction port 18 and an exhaust port 19. The inlet 18 is connected to a cylinder containing a reaction gas or a cylinder containing a dilution gas through a pipe (not shown), and an appropriate amount of these gases is supplied as necessary. Further, the exhaust port 19 is connected to a vacuum pump (not shown) through a pipe (not shown), and the gas in the film forming chamber 2 is discharged from here.

The susceptor S ₁ is placed on a rotatable susceptor base 20 installed in the film forming chamber 2. The substrate W ₁ can be heated by a heater (not shown), and after the susceptor S ₁ is placed in the film forming chamber 2, the substrate W ₁ has a predetermined structure with the first opening / closing part 3 closed. Film processing is performed. In the example of FIG. 1, film formation can be performed on four substrates at the same time.

For example, the substrate W ₁ is heated to 1100 ° C. to 1200 ° C. with a heater while flowing hydrogen gas under a reduced pressure of several tens of torr. Then, by rotating the susceptor pedestal 20 while introducing a reactive gas, it is possible to grow an epitaxial layer of silicon having a uniform thickness on all the substrate W _1. For example, in a power semiconductor application, a thick film of 10 μm or more, most often about 10 μm to 100 μm, is formed on a 300 mm silicon wafer. In order to form a thick film, it is preferable to increase the number of rotations of the substrate during film formation, for example, about 900 rpm.

After the film formation process is completed, the first opening / closing unit 3 is opened, and the substrate-susceptor transfer robot 17 moves the substrate W ₁ together with the susceptor S ₁ from the film formation chamber 2 to the substrate standby unit 4. At this time, the substrate immediately after being taken out from the film forming chamber 2 is heated by a heater provided in the substrate-susceptor transfer robot 17 to a predetermined temperature by a portion where the susceptor S ₁ is placed. W ₁ and as rapid temperature changes in the susceptor S ₁ is not occur, it is possible to prevent the occurrence of cracks in the substrate W ₁ and film. Further, by doing so, it is not necessary to take out the substrate W ₁ and the susceptor S ₁ after waiting for a sufficient temperature drop in the film forming chamber 2, so that the operating rate of the film forming apparatus 1 can be improved. it can. Furthermore, the heating time until the next substrate carried into the substrate standby unit 4 is processed can be shortened.

For example, when the temperature in the film formation chamber 2 reaches about 800 ° C., the first opening / closing part 3 is opened. The temperature of the portion where the susceptor S ₁ is placed by the substrate-susceptor transfer robot 17 is heated to 500 ° C. to 600 ° C. by a heater, thereby causing a sudden temperature change to the susceptor S ₁ and the substrate W _1. These can be taken out from the film formation chamber 2 without any problems.

After removing the susceptor S ₁ and the substrate W ₁ , the first opening / closing part 3 is closed and the temperature of the heater is gradually lowered. When the susceptor S ₁ and the substrate W ₁ are sufficiently cooled, the second opening / closing unit 11 is opened, and the susceptor S ₁ and the substrate W ₁ are transferred into the substrate-susceptor mounting unit 8 by the substrate-susceptor transfer robot 17. .

Next, the second opening / closing part 11 is closed, and nitrogen gas is supplied from the introduction port 14 to return the inside of the substrate-susceptor mounting part 8 to atmospheric pressure. Next, the third opening / closing unit 12 is opened, and the substrate W ₁ plate on which the film has been formed by the substrate transfer robot 10 is stored in the cassette 21. On the other hand, the susceptor S ₁ is transferred from the fourth opening / closing unit 22 to the cleaning unit 5 by the susceptor transfer robot 7.

In the cleaning unit 5, the etching removal of the film formed on the surface of the susceptor S ₁ is performed. Although not shown in detail, the cleaning unit 5 is provided with a plasma reaction chamber. The heater heats the susceptor to a predetermined temperature, exhausts the gas in the plasma reaction chamber from the exhaust port, and introduces the etching gas from the introduction port. As an etching gas, for example, a mixed gas of CF ₄ , N ₂ O and SiH _4, a mixed gas of SF ₄ and O ₂ , or the like can be used. By generating a plasma by applying a high frequency to an electrode provided in the plasma reaction part, the film and dirt deposited on the surface of the susceptor S ₁ can be removed by etching, and the susceptor S ₁ can be cleaned. If ClF ₃ gas is used as the etching gas, heating is not necessary, and it is not necessary to provide a heater in the cleaning unit 5.

After finishing the cleaning of the susceptor S ₁ is by the susceptor transfer robot 7 conveys the susceptor S ₁ of cleaned susceptor standby chamber 6.

Although omitting the description, and the susceptor S ₂ of the substrate W ₂ is placed, for susceptor S ₃ of the substrate W ₃ is also placed, in the same way as the susceptor S ₁ of the substrate W ₁ is placed The substrate-susceptor mounting portion 8 is taken out into the atmosphere. Thereafter, the substrate W ₂ and the substrate W ₃ are stored in the cassette 21. Further, the susceptor S ₂ and the susceptor S ₃ are accommodated in the susceptor standby chamber 6 after the cleaning unit 5 removes the film and dirt adhering to the surface. The cleaning in the cleaning unit 5 is performed while another substrate (for example, the substrate W ₁ ) is being processed in the film formation chamber 2. That is, since the film forming process is not interrupted for cleaning, the operating rate in the film forming chamber 2 can be improved and the film can be formed efficiently.

On the other hand, the substrate W and the susceptor S on which the film forming process is performed next are taken out from the cassette 9 and the susceptor standby chamber 6 and carried into the substrate standby unit 4 and the substrate-susceptor mounting unit 8 in the same manner as described above. . For example, a plurality of substrates W ₄ (not shown) are placed on the susceptor S ₄ (not shown) cleaned by the cleaning unit 5 in the substrate standby unit 4 while the film formation process of the substrate W ₁ is performed. Thus, a new film forming process can be performed in the film forming chamber 2 in place of the substrate W ₁ and the susceptor S ₁ that have completed the film forming process.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

It is a typical top view of the film-forming apparatus in this Embodiment. It is a top view of the part in which a susceptor is mounted in this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film-forming apparatus 2 Film-forming chamber 3 1st opening-and-closing part 4 Substrate standby part 5 Cleaning part 6 Susceptor standby chamber 7 Susceptor transfer robot 8 Substrate-susceptor mounting part 9, 21 Cassette 10 Substrate transfer robot 11 2nd Opening / closing part 12 Third opening / closing part 13, 16, 19 Exhaust port 14, 15, 18 Introduction port 17 Substrate-susceptor transfer robot 20 Susceptor base 22 Fourth opening / closing unit

Claims (5)

A film forming apparatus for performing a film forming process on a substrate placed in a film forming chamber,
A substrate standby unit connected to the film formation chamber via an opening / closing unit;
A transfer means for automatically transferring a susceptor on which a plurality of substrates are placed between the substrate standby section and the film forming chamber;
A cleaning unit provided outside the film forming chamber for cleaning the susceptor after the film forming process is completed;
The film forming apparatus, wherein the substrate standby section is provided with a heating means for heating the susceptor carried out of the film forming chamber and the substrate. The film forming apparatus according to claim 1, wherein the heating unit heats a portion of the transport unit on which the susceptor is placed. Substrate standby for automatically transporting a susceptor on which a plurality of substrates are placed into a film formation chamber, simultaneously performing film formation on the plurality of substrates, and then connecting to the film formation chamber via an opening / closing unit The substrate and the susceptor are transported to a part, and then the film adhering to the surface of the susceptor is removed by a cleaning part provided outside the film formation chamber. The substrate standby part is provided with a heating means, and when the heating means is operated to open a predetermined temperature difference between the film formation chamber and the substrate standby part, the opening / closing part is opened, and the film formation chamber The film forming method according to claim 3, wherein the substrate and the susceptor are transferred from the substrate to the substrate standby unit. While the film forming process is being performed, a plurality of other substrates are placed on and put into another susceptor cleaned by the cleaning unit in the substrate standby unit, and the substrate and the susceptor after the film forming process are completed. Instead, a new film forming process is performed in the film forming chamber.

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