JP5200972B2 - Board manufacturing equipment - Google Patents

Description

  The present invention relates to a substrate manufacturing apparatus for forming a crystal substrate on a seed substrate by immersing the seed substrate in a melt in a crucible placed inside a pressurized and heated processing vessel.

  In recent years, it has been proposed to use gallium nitride as a power semiconductor. As such a method for producing gallium nitride, for example, a gas phase method in which a seed substrate is exposed to a raw material gas to form a crystal substrate made of a gallium nitride crystal on the seed substrate, and a seed substrate is used as a raw material. A liquid phase method has been proposed in which a crystal substrate made of a gallium nitride crystal is formed on a seed substrate by being immersed in a melt.

For example, Patent Document 1 proposes a method of forming a crystal substrate made of a gallium nitride crystal by a liquid phase method.
In this Patent Document 1, a melt containing gallium and sodium acting as a flux is placed in a crucible in a hermetic pressure-resistant and heat-resistant container, and the seed substrate is immersed in the melt to manufacture the crystal substrate. Yes.

JP 2005-263622 A

  However, gallium nitride is currently manufactured at a laboratory level, and it is not considered to manufacture gallium nitride in large quantities. Therefore, in the future, it will be necessary to propose a method for enabling mass production of gallium nitride.

For example, in the manufacturing method and the manufacturing apparatus disclosed in Patent Document 1, the lid provided on the upper part of the hermetic pressure-resistant and heat-resistant container is opened, and the seed substrate is placed inside from the upper part of the opened hermetic pressure-resistant and heat-resistant container. The crucible inside is put in and out. However, when putting in and out the crucible containing the seed substrate from the top of the hermetic pressure and heat resistant container, it is necessary to put the crucible into and out of a narrow space surrounded by the side wall of the hermetic pressure and heat resistant container. Workability is poor.
In general, piping for supplying nitrogen gas into the hermetic pressure-resistant and heat-resistant container is inserted into the hermetic pressure-resistant and heat-resistant container from above. For this reason, in order to be able to open the upper part of the hermetic pressure-resistant and heat-resistant container, it is necessary to consider the shape and material of the pipe and the like.

  Such a problem is caused by immersing the crystal substrate on the seed substrate by immersing the seed substrate in the melt in a crucible placed inside a pressurized and heated processing container (sealing pressure-resistant heat-resistant container). This occurs when the forming method is used, and is not necessarily a particular problem in the case of manufacturing a gallium nitride substrate. However, the above-mentioned problem appears particularly prominently in the production of a gallium nitride substrate using sodium or the like that requires handling as in the liquid phase method.

  The present invention has been made in view of the above-mentioned problems, and a crystal substrate is formed on a seed substrate by immersing the seed substrate in a melt in a crucible placed inside a pressurized and heated processing vessel. An object of the present invention is to achieve mass production of a crystal substrate by improving workability in a substrate manufacturing apparatus for forming a substrate.

  The present invention adopts the following configuration as means for solving the above-described problems.

  1st invention is the board | substrate manufacturing apparatus which forms a crystal substrate on the said seed substrate by immersing a seed substrate in a melt in the crucible mounted in the inside of the processing container pressurized and heated. A configuration is adopted in which the bottom portion of the processing container is capable of placing the crucible and being removable downward.

  According to a second aspect of the present invention, in the first aspect of the present invention, a storage portion that is connected to the lower side of the processing container and can store the bottom of the processing container inside, and a melt in the crucible inside the storage portion. A configuration in which an inert gas supply device for supplying an inert gas is provided.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the connection unit includes the plurality of processing containers and includes a handling device that is connected to the plurality of processing containers and delivers the seed substrate therein. And an inert gas supply device for supplying an inert gas to the melt in the crucible inside the connecting portion.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, a configuration is provided in which a treatment is performed on the seed substrate on which the crystal substrate is formed and a post-processing device connected to the connection portion is provided. .

  According to a fifth invention, in any one of the first to fourth inventions, the seed substrate is a sapphire substrate including a gallium nitride layer, the melt contains gallium and sodium, and the melt is contained in the processing vessel. A configuration is adopted in which nitrogen gas is supplied therein and the crystal substrate is a gallium nitride substrate.

According to the present invention, the bottom of the processing container can be mounted with a crucible and can be removed downward.
For this reason, according to this invention, a crucible can be easily taken out of the processing container by removing the bottom part of the processing container in which the crucible is placed. Moreover, according to this invention, a crucible can be easily put in the inside of a processing container by mounting a crucible in the bottom part of the removed processing container and attaching the said bottom part. That is, according to the present invention, it is not necessary to put in and out the crucible in a narrow region surrounded by the side wall of the processing container, and the workability is improved.
Therefore, according to the present invention, in a substrate manufacturing apparatus for forming a crystal substrate on a seed substrate by immersing the seed substrate in a melt in a crucible placed inside a pressurized and heated processing vessel, It becomes possible to improve the workability and realize mass production of crystal substrates.

It is a top view which shows schematic structure of the board | substrate manufacturing apparatus in one Embodiment of this invention. It is a front view which shows schematic structure of the board | substrate manufacturing apparatus in one Embodiment of this invention. It is sectional drawing of the reaction unit with which the substrate manufacturing apparatus in one Embodiment of this invention is provided. It is sectional drawing for demonstrating operation | movement of the reaction unit with which the substrate manufacturing apparatus in one Embodiment of this invention is provided.

  Hereinafter, an embodiment of a substrate manufacturing apparatus according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

  1 and 2 are diagrams showing a schematic configuration of the substrate manufacturing apparatus S of the present embodiment. FIG. 1 is a plan view of the substrate manufacturing apparatus S of the present embodiment, and FIG. 2 is a front view of the substrate manufacturing apparatus S of the present embodiment.

  As shown in FIGS. 1 and 2, the substrate manufacturing apparatus S of this embodiment includes a reaction unit 1, a cleaning unit 2 (post-processing apparatus), a transfer unit 3 (connecting portion), and a nitrogen gas supply apparatus 4 (not used). Active gas supply device).

  The substrate manufacturing apparatus S of this embodiment includes three reaction units 1 that are connected to the transport unit 3. And the reaction unit 1 has the external shape where the accommodating part 5 and the reaction container 6 (processing container) were piled up in the height direction, as shown in FIG.

  FIG. 3 is a cross-sectional view of the reaction unit 1. As shown in this figure, the reaction vessel 6 is accommodated and supported by a substantially cylindrical outer vessel 6a constituting the outer shape of the reaction vessel 6 and a support portion 6c inside the outer vessel 6a and a heat insulating material. And a cylindrical inner container 6b.

  And in the board | substrate manufacturing apparatus S of this embodiment, the bottom part 6d of the reaction container 6 comprised by the bottom part 6a1 of the outer container 6a and the bottom part 6b1 of the inner container 6b is made removable with respect to a container main body. .

  The bottom 6a1 of the outer container 6a and the container main body can be connected by a clutch structure 6e, and the fixed state of the bottom 6a1 can be changed by rotating the bottom 6a1 of the outer container 6a. The reaction vessel 6 is sealed by fixing the bottom 6a1 of the outer vessel 6a to the vessel body.

  In such a reaction vessel 6, the crucible 10 is placed on the bottom 6d. And the crucible 10 is accommodated in the inside of the inner container 6b of the reaction container 6 by fixing the bottom part 6d with respect to a container main body in the state in which the crucible 10 was mounted.

  A heater 7 is installed inside the inner container 6b. The outer container 6a is connected to a pressurization / decompression device (not shown). Then, the inside of the reaction vessel 6 can be heated and pressurized and depressurized by the heater 7 and the pressurizing and depressurizing device.

The accommodating portion 5 has a hollow box shape and is connected to the lower side of the reaction vessel 6. And the accommodating part 5 has an internal space which can accommodate the bottom part 6d of the reaction container 6, as shown in FIG.
Inside the accommodating portion 5, a driving device 8 is installed that is connected to the bottom portion 6 d of the reaction vessel 6 and that moves the bottom portion 6 d up and down and rotates.
Then, the bottom 6d of the reaction vessel 6 fixed to the vessel main body is rotated and lowered by the driving device 8 to be removed and accommodated in the accommodating portion 5 as shown in FIG.

  In addition, the reaction unit 1 is connected to the transport unit 3 via the storage unit 5. And the door which can be opened and closed is provided in the connection part of the accommodating part 5 and the conveyance unit 3, and the crucible 10 is comprised between the reaction unit 1 and the conveyance unit 3 through the said door so that a movement is possible. Yes.

Note that the seed substrate 20 is immersed in the melt 30 in the crucible 10 placed in the reaction vessel 6 pressurized and heated in the reaction unit 1 configured as described above. A crystal substrate is formed.
In the substrate manufacturing apparatus S of the present embodiment, a sapphire substrate having a gallium nitride layer is used as the seed substrate 20, gallium and sodium are included in the melt 30, and nitrogen is introduced near the melt 30 inside the reaction vessel 6. A gallium nitride substrate is formed on the seed substrate 20 by supplying a gas.

Returning to FIG. 1 and FIG. 2, the cleaning unit 2 performs a cleaning process as a process for the seed substrate 20 on which the crystal substrate is formed in the reaction unit 1, and is accommodated in the crucible 10 taken out from the reaction unit 1. By washing the seed substrate together with the crystal substrate, chemicals such as sodium and gallium adhering to the surface of the substrate are washed away.
And the said washing | cleaning unit 2 is connected to the conveyance unit 3 similarly to the said reaction unit 1, as shown in FIG.

The transport unit 3 is a unit in which each reaction unit 1 and the cleaning unit 2 are connected, and a handling device 3b that transfers the seed substrate 20 by moving the crucible 10 to a space surrounded by the outer wall 3a is installed. Has been.
Then, the handling device 3 b moves the crucible 10 between the reaction unit 1 and the cleaning unit 2. Further, a door connecting the outside and the inside is installed on the outer wall portion 3a of the transport unit 3, and a load port 3c is installed outside the door. The handling device 3b delivers the crucible 10 or the seed substrate 20 to the load port 3c.

The nitrogen gas supply device 4 supplies nitrogen gas into the crucible 10 placed in the reaction vessel 6 and supplies nitrogen gas to the cleaning unit 2, the transport unit 3, and the storage unit 5.
For example, as shown in FIG. 3, the nitrogen gas supply device 4 passes nitrogen through the reaction vessel 6 from above, and the nitrogen gas is supplied to the melt 30 via a pipe 4 a disposed near the melt 30 whose tip is stored in the crucible 10. Supply gas. The inside of the substrate manufacturing apparatus S is pressurized with pure nitrogen gas or an inert gas mixed gas containing at least nitrogen gas.

  Next, the operation of the substrate manufacturing apparatus S of the present embodiment configured as described above will be described. In addition, the board | substrate manufacturing apparatus S of this embodiment is provided with the control apparatus not shown. The following operations are performed with the control device as the subject unless otherwise specified.

For example, when the crucible 10 is placed in the load port 3c by an operator or an external transfer device, the crucible 10 is taken into the outer wall 3a by the handling device 3b of the transfer unit 3.
A seed substrate 20 is accommodated in the crucible 10.

Subsequently, the crucible 10 is transported to one of the reaction units 1 in which the crucible 10 does not exist by the handling device 3b.
The reaction unit 1 in which the crucible 10 does not exist is in a standby state in which the container 5 is opened and the bottom 6d of the reaction vessel 6 is lowered. However, the opening of the container 5 and the lowering of the bottom 6d may be after the crucible 10 is transported to the front of the reaction unit 1 by the handling device 3b.

Subsequently, the crucible 10 is placed on the bottom 6d lowered in the accommodating portion 5 by the handling device 3b.
When the crucible 10 is placed on the bottom 6d, the bottom 6d is raised and rotated by the driving device 8 and attached to the container body and fixed. As a result, the crucible 10 is placed inside the reaction vessel 6.

When the crucible 10 is thus placed inside the reaction vessel 6, the inside of the reaction vessel 6 is brought into a vacuum (depressurized) state and then pressurized and heated by the heater 7 and the pressure-reducing device. Subsequently, molten gallium and molten sodium are introduced into the crucible 10 through a pipe.
As a result, the seed substrate 20 in the crucible 10 is immersed in the melt 30 containing gallium and sodium.

Subsequently, nitrogen gas is supplied from the nitrogen gas supply device 4 to the vicinity of the melt 30 in the crucible 10 via the pipe 4a.
As a result, nitrogen gas dissolves in the melt 30, and a crystal substrate is gradually formed on the surface of the seed substrate 20 immersed in such a melt 30. Note that a pressurized state is preferable so that the liquid metal does not easily evaporate.

  When the crystal substrate is formed on the surface of the seed substrate 20 in this manner, the sodium / gallium alloy (melt 30) is sucked and removed using a pipe. The crucible 10 is removed from the container body by the driving device 8 with the bottom 6d lowered and rotated. Then, the crucible 10 placed on the bottom 6 d is taken out of the storage unit 5 by the handling device 3 and further conveyed to the cleaning unit 2. The crucible 10 transported to the cleaning unit 2 is cleaned together with the seed substrate 20, for example, and then transported to the load port 3c again by the handling device 3b.

By such a process, a crystal substrate made of gallium nitride can be formed on the surface of the seed substrate 20.
While the cleaning process is being performed by the cleaning unit 2, the next crucible 10 is transferred from the load port 3c to the vacant reaction unit 1, and the crystal substrate is formed as described above.

  In the substrate manufacturing apparatus S of the present embodiment, nitrogen gas that is inactive with respect to the melt 30 (particularly sodium) is contained inside the accommodating portion 5 of the reaction unit 1, inside the outer wall portion 3a of the transfer unit 3, And the cleaning unit 2 is supplied. Thus, the crucible 10 is transported in an environment filled with nitrogen gas.

According to the substrate manufacturing apparatus S of the present embodiment as described above, the bottom 6d of the reaction vessel 6 can be mounted with the crucible 10 and detachable downward.
For this reason, according to the substrate manufacturing apparatus S of this embodiment, the crucible 10 can be easily taken out of the reaction vessel 6 by removing the bottom 6d of the reaction vessel 6 on which the crucible 10 is placed. Further, according to the substrate manufacturing apparatus S of the present embodiment, the crucible 10 is easily placed in the reaction vessel 6 by placing the crucible 10 on the bottom 6d of the removed reaction vessel 6 and attaching the bottom 6d. be able to. That is, according to the substrate manufacturing apparatus S of the present embodiment, it is not necessary to put the crucible 10 in and out of a narrow region surrounded by the side wall of the reaction vessel 6 and workability is improved.
Therefore, according to the substrate manufacturing apparatus S of the present embodiment, the seed substrate 20 is immersed in the melt 30 in the crucible 10 placed in the pressurized and heated reaction vessel 6, so In a substrate manufacturing apparatus for forming a crystal substrate, the workability can be improved and mass production of the crystal substrate can be realized.

  Further, in the substrate manufacturing apparatus S of the present embodiment, nitrogen gas or an inert gas containing nitrogen is supplied to the inside of the accommodating portion 5 of the reaction unit 1, the inside of the outer wall portion 3 a of the transfer unit 3, and the cleaning unit 2. Supply. For this reason, it is prevented that the melt 30 reacts with oxidation etc. with the conveyance of the crucible 10.

Further, the substrate manufacturing apparatus S of the present embodiment includes a plurality of reaction units 1, and includes a transport unit 3 that transports the crucible 10 to these reaction units 1.
For this reason, it becomes possible to grow crystal substrates on a plurality of seed substrates 20 at the same time.

In the embodiment, the cleaning unit 2 is provided.
For this reason, it is possible to perform post-processing on the seed substrate 20 on which the crystal substrate has been grown in the substrate manufacturing apparatus S.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, the seed substrate 20 is a sapphire substrate having a gallium nitride layer, the melt 30 contains gallium and sodium, nitrogen gas is supplied into the melt 30 inside the reaction vessel 6, and the crystal The configuration in which the substrate is a gallium nitride substrate has been described.
However, the present invention is not limited to this, and a crystal substrate is formed on a seed substrate by immersing the seed substrate in a melt in a crucible placed in a pressurized and heated processing vessel. It is possible to apply to the whole substrate manufacturing apparatus.

  In addition, the present invention can be applied to a substrate manufacturing apparatus that has a single reaction unit 1 and does not include the cleaning unit 2 and the transfer unit 3, for example.

Moreover, in the said embodiment, the structure which moves the seed substrate 20 by moving the crucible 10 with the handling apparatus 3b was demonstrated.
However, the present invention is not limited to this, and the handling device 3b may be configured to be able to deliver the seed substrate 20 to the crucible 10, and the seed substrate 20 may be directly moved by the handling device 3b.

Moreover, in the said embodiment, the structure provided with the three reaction units 1 was demonstrated.
However, the present invention is not limited to this, and it is possible to employ a configuration including more or fewer reaction units 1.

Moreover, in the said embodiment, the structure provided with the washing | cleaning unit 2 as a post-processing apparatus which performs the process with respect to the seed substrate 20 in which the crystal substrate was formed was demonstrated.
However, the present invention is not limited to this, and a configuration including other post-processing devices may be adopted.
As such another post-processing apparatus, for example, a processing apparatus that performs processing such as separating the seed substrate 20 and the crystal substrate can be used.

Moreover, in the said embodiment, the structure provided with the single washing | cleaning unit 2 as a post-processing apparatus was demonstrated.
However, the present invention is not limited to this, and a configuration including a plurality of post-processing devices may be employed.

Moreover, in the said embodiment, the gas supplied into the crucible 10 and an inert gas were made common by using nitrogen gas as an inert gas, and, thereby, the apparatus structure was simplified.
However, the present invention is not limited to this, and the gas supply device supplied to the crucible 10 and the gas supply device supplied to the storage unit 5 or the like have different configurations and are individually controlled to supply gas. Also good. A rare gas such as argon may be used as the inert gas.

  S: Substrate manufacturing apparatus, 1 ... Reaction unit, 2 ... Cleaning unit (post-processing apparatus), 3 ... Transfer unit (connection part), 3b ... Handling apparatus, 4 ... Nitrogen gas supply apparatus (inert) Gas supply device), 5... Storage section, 6... Reaction vessel (processing vessel), 6 d... Bottom, 10.

Claims (3)

A substrate manufacturing apparatus for forming a crystal substrate on a seed substrate by immersing the seed substrate in a melt in a crucible placed inside a pressurized and heated processing container,
A plurality of said processing containers;
A connecting unit having a handling device to which a plurality of the processing containers are connected and for delivering the seed substrate therein;
An inert gas supply device for supplying an inert gas to the melt in the crucible inside the connection part;
A receiving portion connected to the lower side of the processing vessel and capable of receiving the bottom of the processing vessel therein;
With
The bottom of the processing container can be placed with the crucible containing the seed substrate, and can be removed downward leaving other parts other than the bottom of the processing container. A substrate manufacturing apparatus. Substrate manufacturing apparatus according to claim 1, characterized in that it comprises a post-processing apparatus connected to the connecting portion performs the processing for the seed substrate with the crystalline substrate is formed. The seed substrate is a sapphire substrate having a gallium nitride layer, the melt contains gallium and sodium, nitrogen gas is supplied into the melt inside the processing vessel, and the crystal substrate is a gallium nitride substrate. The substrate manufacturing apparatus according to claim 1 or 2 .

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