JP5251015B2 - Heat treatment apparatus and heat treatment method - Google Patents

Description

  The present invention mainly forms an atmosphere maintained at a high vacuum and high temperature, or a high-temperature atmosphere containing a little inert gas, and under this atmosphere, chemical changes and physical changes such as crystal growth, chemical reaction or film formation The present invention relates to a structure of a heat treatment apparatus for generating a heat treatment object.

  Conventionally, for example, in a heat treatment apparatus called a crystal growth furnace or a chemical reaction furnace for performing CVD (Chemical Vapor Deposition) or the like, a heating chamber that maintains a vacuum atmosphere or a gas atmosphere at a high temperature state, There is known a configuration that includes a heating means for heating a processing object and performs a heat treatment on the processing object disposed in the heating chamber.

For example, Patent Document 1 includes a main heating chamber and a preheating chamber in a heat treatment apparatus of this type, and first performs a preheating process in the preheating chamber, and then moves an object to be processed from the preheating chamber to the main heating chamber. The structure which performs this heat processing by this is disclosed. Patent Documents 2 to 5 also disclose a heat treatment apparatus having a similar configuration.
JP 2004-292305 A JP 2004-297034 A JP 2004-210772 A JP 2005-273931 A JP 2006-41544 A

  However, all of the configurations of Patent Documents 1 to 5 require a considerable time for taking the workpiece into and out of the preheating chamber and moving the workpiece between the preheating chamber and the main heating chamber. Was. For this reason, there was room for improvement in terms of thermal efficiency and throughput. Further, the mechanism for taking in / out and moving is complicated, and there is still room for improvement from the viewpoint of simplification of the configuration.

  The present invention has been made in view of the above circumstances, and its main purpose is to allow the temperature of the object to be processed to reach a desired temperature quickly, which is excellent in thermal efficiency and throughput, and has a simple configuration. It is to provide a heat treatment apparatus.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to the 1st viewpoint of this invention, the heat processing apparatus of the following structures is provided. That is, a first chamber for heating an object to be processed to a temperature of 1,000 ° C. or more and 2,400 ° C. or less, a second chamber adjacent to the first chamber, the second chamber, and the first chamber A moving mechanism for moving the object to be processed. Inside the first chamber, a heater arranged to heat the object to be processed from the surroundings, and a first multilayer arranged to reflect the heat of the heater toward the object to be processed A heat reflecting metal plate. The moving mechanism includes a second multilayer heat reflecting metal plate that can move together with the object to be processed. When the object to be processed is in the second chamber, the second multilayer heat reflecting metal plate is positioned so as to separate the first chamber and the second chamber, and a part of the heat generated from the heater is generated. It is configured to be supplied to the second chamber via the second multilayer heat reflecting metal plate and thereby to preheat the object to be processed in the second chamber.

  Thereby, since the temperature of the second chamber is raised using the heat of the first chamber, it is possible to reduce the number of heaters necessary for the preheating or not to install at all. As a result, the configuration of the heat treatment apparatus can be remarkably simplified. In addition, after the preheating in the second chamber is completed, the second multilayer heat reflecting metal plate moves together with the object to be processed by simply moving the object to be processed to the adjacent first chamber, and the first chamber and the first chamber. The two rooms are in communication. Therefore, the mechanism for moving the workpiece between the first chamber and the second chamber can be simplified, and the time required for the movement can be shortened. Therefore, this heat treatment can be started immediately to achieve a rapid temperature increase, and the thermal efficiency and throughput are good.

  In the heat treatment apparatus, it is preferable that the number of stacked second multilayer heat reflecting metal plates is smaller than the number of stacked first multilayer heat reflecting metal plates.

  Thereby, at the time of preliminary heating, a part of the heat in the first chamber is appropriately distributed to the second chamber side through the second multilayer heat reflecting metal plate. Therefore, the temperature of the second chamber can be appropriately increased and the preheating treatment can be easily performed.

  The heat treatment apparatus preferably has the following configuration. That is, the moving mechanism includes a third multilayer heat reflecting metal plate that can move together with the workpiece. When the object to be processed is in the second chamber, the third multilayer heat reflecting metal plate is positioned so as to separate the second chamber from the outside. When the object to be processed is in the first chamber, the third multilayer heat reflecting metal plate is positioned so as to separate the first chamber from the second chamber.

  Thereby, at the time of preliminary heating, the temperature drop of the second chamber can be satisfactorily prevented by the third multilayer heat reflecting metal plate. Further, during the main heat treatment, the third multilayer heat reflecting metal plate separates the first chamber and the second chamber, so that the object to be treated in the first chamber can be efficiently heated.

  In the heat treatment apparatus, it is preferable that the third multilayer heat-reflecting metal plate is formed by laminating metal plates having a large number of through holes while varying the positions of the through holes.

  Thereby, the gas generated from the object to be processed during the main heat treatment can be exhausted well through the through holes of the metal plates of the third multilayer heat reflecting metal plate. Therefore, it is possible to prevent contamination by the object to be processed and the gas in the first chamber. On the other hand, since the heat in the first chamber is well blocked by the third multilayer heat reflecting metal plate, the thermal efficiency during the main heat treatment can be maintained well.

  The heat treatment apparatus preferably has the following configuration. That is, the moving mechanism includes a fourth multilayer heat reflecting metal plate that can move together with the object to be processed. When the object to be processed is in the first chamber, the fourth multilayer heat reflecting metal plate is positioned so as to separate the second chamber from the outside.

  Thereby, at the time of this heat processing, since the temperature fall of a 2nd chamber can be prevented with a 4th multilayer heat | fever reflective metal plate, a 1st chamber can be easily maintained in a high temperature atmosphere.

The heat treatment apparatus preferably has the following configuration. That is, the third chamber surrounded by the multilayer heat reflecting metal plate is provided adjacent to the outside of the second chamber. The second chamber is adjacent to the first chamber in the vertical direction. The third chamber is adjacent to the second chamber in the vertical direction. The moving mechanism includes a fourth multilayer heat reflecting metal plate that can move together with the object to be processed. When the object to be processed is in the first chamber, the fourth multilayer heat reflecting metal plate is positioned so as to separate the second chamber from the third chamber.

  Thereby, the loss which the heat | fever of a 2nd chamber etc. escapes can be reduced with the simple structure which provides a 3rd chamber.

  In the heat treatment apparatus, when the object to be processed is in the second chamber, the fourth multilayer heat reflecting metal plate is preferably positioned so as to separate the third chamber from the outside.

  Thereby, since the third chamber is closed by the third multilayer heat-reflecting metal plate and the fourth multilayer heat-reflecting metal plate during the preheating treatment, the heat insulation effect can be obtained with a simple configuration.

  The heat treatment apparatus preferably has the following configuration. That is, a rod is connected to the fourth multilayer heat reflecting metal plate. The rod is located on the opposite side of the second chamber with the third chamber interposed when the workpiece is in the second chamber.

  Thereby, the loss which the heat | fever of a 2nd chamber etc. transfers along a rod and escapes can be reduced by a 3rd chamber. Therefore, the efficiency of the heat treatment is further improved, and thermal damage to the rod can be prevented.

  In the heat treatment apparatus, it is preferable that the fourth multilayer heat-reflecting metal plate is formed by laminating metal plates having a large number of through holes with different positions of the through holes.

  Thereby, the gas generated from the workpiece during the main heat treatment can be exhausted well through the through holes of the metal plates of the fourth multilayer heat reflecting metal plate. Therefore, it is possible to prevent contamination by the object to be processed and the gas in the first chamber and the second chamber. On the other hand, since the heat in the second chamber is well blocked by the fourth multilayer heat reflecting metal plate, an excessive temperature drop in the second chamber can be prevented, and the thermal efficiency during the main heat treatment can be maintained well.

  The heat treatment apparatus preferably has the following configuration. That is, the moving mechanism includes a fifth multilayer heat reflecting metal plate that can move together with the object to be processed. When the object to be processed is in the first chamber, the fifth multilayer heat reflecting metal plate is positioned so as to separate the third chamber from the outside.

  Thereby, the loss which heat escapes at the time of this heat processing can further be reduced by the heat insulation effect of the 3rd chamber.

The heat treatment apparatus preferably has the following configuration. That is, the fourth chamber surrounded by the multilayer heat reflecting metal plate is provided adjacent to the outside and the lower side of the third chamber. When the object to be processed is in the second chamber, the fifth multilayer heat reflecting metal plate is positioned so as to separate the fourth chamber from the outside.

  Thereby, the loss which the heat | fever of a 2nd chamber etc. escapes can be reduced further by two 3rd chambers.

  The heat treatment apparatus preferably has the following configuration. That is, a rod is connected to the fifth multilayer heat reflecting metal plate. The rod is located on the opposite side of the second chamber with the third chamber interposed when the object to be processed is in the first chamber.

  Thereby, at the time of this heat processing, the loss which the heat | fever of a 1st chamber transmits along a rod and escapes can be reduced by a 3rd chamber. Therefore, the efficiency of the heat treatment is further improved, and thermal damage to the rod can be prevented.

  In the heat treatment apparatus, it is preferable that the workpiece in the second chamber can be preheated to a temperature of 500 ° C. or higher.

  Thereby, the heat processing apparatus suitable for the process which needs preheating at high temperature can be provided.

  The heat treatment apparatus preferably has the following configuration. In other words, the moving mechanism includes a support that supports the object to be processed, and a rod that is coupled to the support. The rod is connected to the support through a temperature insulator.

  Thereby, the loss which the heat | fever of a 1st chamber or a 2nd chamber escapes along a rod can be reduced with a temperature insulator, and the further efficiency improvement of heat processing can be achieved.

  The heat treatment apparatus preferably has the following configuration. In other words, the moving mechanism includes a support that supports the object to be processed, and a rod that is coupled to the support. When the object to be processed is in the first chamber, the rod and the support can be disconnected.

  Thereby, the loss which the heat | fever of a 1st chamber conveys to a rod and escapes can be reduced, and the further efficiency improvement of heat processing can be aimed at.

  In the heat treatment apparatus, the second chamber includes a multilayer heat reflecting metal plate, and a passage hole is formed in the multilayer heat reflecting metal plate, and an object to be processed can be taken in and out of the second chamber through the passage hole. It is preferable to configure.

  Thereby, with the simple structure, the taking in / out of to-be-processed object to a 2nd chamber is realizable.

  In the heat treatment apparatus, it is preferable that an opening / closing member capable of opening / closing the passage hole is provided.

  Thus, by closing the opening / closing member during preheating or the like, it is possible to reduce the heat loss of the second chamber and further increase the efficiency of the heat treatment.

  The heat treatment apparatus preferably has the following configuration. That is, the second chamber includes a multilayer heat reflecting metal plate, and is configured such that a passage space can be formed by moving at least a part of the multilayer heat reflecting metal plate. Through this passage space, an object to be processed can be taken in and out of the second chamber.

  Thereby, with the simple structure, the taking in / out of to-be-processed object to a 2nd chamber is realizable.

  The heat treatment apparatus preferably has the following configuration. That is, a transport mechanism capable of taking in and out the workpiece from the second chamber is provided. The transport mechanism includes an arm, and is configured to transport an object to be processed by the arm.

  Or it is preferable that the said conveyance mechanism is comprised by the rotary table type.

  Thereby, with the conveyance mechanism of a simple structure, withdrawing / inserting to-be-processed object to a 2nd chamber is realizable.

  The heat treatment apparatus preferably has the following configuration. That is, a stock chamber capable of stocking a plurality of objects to be processed in the vertical direction and a transport mechanism capable of transporting the objects to be processed in the horizontal direction between the second chamber and the stock chamber are provided. The second chamber is adjacent to the first chamber in the vertical direction.

  As a result, a plurality of objects to be processed can be stocked, and the preliminary heat treatment and the main heat treatment can be performed one after another, and the throughput can be significantly improved. Moreover, since the said function can be achieved with a compact structure, the installation area of a heat processing apparatus can be reduced.

  In the heat treatment apparatus, the stock chamber is preferably provided with a cooling mechanism for cooling an object to be processed stocked in the stock chamber.

  Thereby, since the to-be-processed object after heat processing can be cooled rapidly, it can transfer to a next process in a short time, and can improve a through-put further.

  The heat treatment apparatus preferably has the following configuration. That is, an introduction chamber is provided for introducing an object to be processed from the atmosphere into the apparatus. The workpiece introduced into the introduction chamber is configured to be transportable to the second chamber.

  Thereby, the workpiece can be easily introduced into the heat treatment apparatus.

In the heat treatment apparatus, it is preferable that the first chamber is configured to be able to be a vacuum of 10 ⁻² Pa or less.

Alternatively, the first chamber is preferably configured so as to be in a rare gas atmosphere into which an inert gas is introduced after reaching a vacuum of 10 ⁻² Pa or less.

  Thereby, for example, a heat treatment apparatus suitable for high-vacuum processing such as a semiconductor process can be provided.

  The heat treatment apparatus preferably has the following configuration. That is, the moving mechanism includes a cradle for placing the object to be processed. The cradle is made of at least one of tantalum carbide, tungsten carbide, tungsten, tantalum, molybdenum, or graphite.

  In the heat treatment apparatus, the heater is preferably made of at least one of tungsten, molybdenum, and tantalum.

  Thereby, the heat processing apparatus suitable for the heat processing at high temperature can be provided.

  Moreover, in the said heat processing apparatus, it is preferable that at least any one of the said cradle or a heater is being fixed to the other member with the attachment screw which consists of tantalum which gave the tantalum carbide.

  Thereby, the seizure of the fixed portion does not occur even at a high temperature, so that a heat treatment apparatus excellent in maintainability can be provided.

  In the heat treatment apparatus, the heater is preferably covered with a cover made of at least one of tungsten, molybdenum, and tantalum.

  Thus, the heater prevents the heater from being exposed to the molecular beam or vapor generated from the object to be processed during the main heat treatment, so that the life of the heater can be extended.

  Moreover, in the said heat processing apparatus, it is preferable that the said cover is being fixed to the other member with the attachment screw which consists of tantalum which gave the tantalum carbide.

  Thereby, the seizure of the fixed portion does not occur even at a high temperature, so that a heat treatment apparatus excellent in maintainability can be provided.

  In the heat treatment apparatus, it is preferable that the first multilayer heat reflective metal plate and the second multilayer heat reflective metal plate are made of at least one of tungsten carbide, tungsten, tantalum, and molybdenum.

  Thereby, the heat processing apparatus suitable for the heat processing at high temperature can be provided.

  In the heat treatment apparatus, at least one of the first multilayer heat-reflecting metal plate and the second multilayer heat-reflecting metal plate is fixed to another member by a mounting screw made of tantalum carbide. preferable.

  Thereby, the seizure of the fixed portion does not occur even at a high temperature, so that a heat treatment apparatus excellent in maintainability can be provided.

  In the heat treatment apparatus, it is preferable that a shield made of at least one of tungsten, molybdenum, or tantalum is disposed around the workpiece in the moving mechanism.

  Thereby, since the heater prevents the heater from being exposed to the molecular beam or steam generated from the object to be processed during the main heat treatment, the life of the heater can be extended.

  In the heat treatment apparatus, the shield is preferably fixed to another member by an attachment screw made of tantalum that has been subjected to tantalum carbide treatment.

  Thereby, the seizure of the fixed portion does not occur even at a high temperature, so that a heat treatment apparatus excellent in maintainability can be provided.

  In the said heat processing apparatus, it is preferable that the temperature detection part is arrange | positioned between the metal plates laminated | stacked in the said 1st multilayer heat reflection metal plate.

  Thereby, the temperature distribution in the first chamber can be measured appropriately and accurately. It is also possible to control the temperature of the main heating unit using this temperature detection unit. As a result, the temperature of the main heating unit is measured with a radiation thermometer via the view port of the chamber, and the problem that the view port becomes cloudy and cannot be measured when feeding back to the control can be solved.

  According to a second aspect of the present invention, there is provided a heat treatment method for heat treating an object to be treated using the heat treatment apparatus, wherein the object to be treated is preheated to a temperature of 500 ° C. or more and 1,000 ° C. or less in the second chamber. A preheating treatment to be performed, and a workpiece to be heated to a temperature of 1,000 ° C. or more and 2,400 ° C. or less in the first chamber by moving the workpiece from the second chamber to the first chamber. Provided is a heat treatment method for performing a heat treatment and a cooling treatment for cooling the workpiece by moving the workpiece from the first chamber to the second chamber after the completion of the main heat treatment.

  Thereby, the temperature of the object to be processed can be uniformly and quickly reached to a desired temperature, and the thermal efficiency and throughput can be improved.

  According to a third aspect of the present invention, there is provided a heat treatment method for heat treating an object to be treated using the heat treatment apparatus, wherein the object to be treated is preheated to a temperature of 500 ° C. or more and 1,000 ° C. or less in the second chamber. The preheating process is performed, and after the workpiece is moved from the second chamber to the first chamber, the temperature of the first chamber is controlled in accordance with the set temperature profile, whereby the workpiece is 1,000. A main heat treatment for heating to a temperature of not less than 0 ° C. and not more than 2,400 ° C., and after the completion of the main heat treatment, the temperature of the first chamber is controlled according to a set temperature profile, thereby A cooling process for cooling an object is provided.

  This makes it possible to heat and cool the temperature of the workpiece with a desired temperature profile. Therefore, it is possible to cope with both a case where the object to be treated is heated suddenly and a case where it is heated slowly, and a heat treatment method having a wide application range can be provided.

In the heat treatment method, it is preferable that the preliminary heat treatment and the main heat treatment are performed in a vacuum of 10 ⁻² Pa or less.

Alternatively, the preliminary heat treatment and the main heat treatment are preferably performed in a dilute gas atmosphere into which an inert gas is introduced after reaching a vacuum of 10 ⁻² Pa or less.

  Thereby, it is possible to provide a method suitable for heat treatment requiring high vacuum such as a semiconductor process.

  In the heat treatment method, the following is preferable. That is, the preliminary heating process and the main heating process are performed in a state where the object to be processed is stored in a container including an upper container and a lower container, and the upper container and the lower container are fitted. This container is made of tantalum subjected to tantalum carbide treatment.

  Thereby, a substantially sealed state of the container is realized, and the internal pressure of the container is kept high with respect to the atmosphere during the main heat treatment in a vacuum or a dilute gas atmosphere. Accordingly, it is possible to prevent impurities from entering the container. In addition, when processing SiC, carbon molecules in the inner space of the container can be selectively occluded in the portion of the container that has been subjected to the tantalum carbide treatment, whereby the inner space of the container can be maintained at a silicon saturated vapor pressure. . Therefore, it is possible to provide a heat treatment method suitable for processing single crystal SiC.

  In the heat treatment method, the following is preferable. That is, the preliminary heating process and the main heating process are performed in a state where the object to be processed is stored in a container including an upper container and a lower container, and the upper container and the lower container are fitted. This container is made of at least one of tungsten carbide, tungsten, and graphite.

  Thereby, a substantially sealed state of the container is realized, and the internal pressure of the container is kept high with respect to the atmosphere during the main heat treatment in a vacuum or a dilute gas atmosphere. Accordingly, it is possible to prevent impurities from entering the container. In addition, a heat treatment method suitable for heat treatment at high temperatures can be provided.

  Next, embodiments of the invention will be described. FIG. 1 is a schematic diagram showing an overall configuration of a high-temperature vacuum furnace according to an embodiment of the present invention.

  A high-temperature vacuum furnace 11 as a heat treatment apparatus shown in FIG. 1 includes a heating furnace 12, a stock chamber 13, an introduction chamber 14, and an observation chamber 15.

  The heating furnace 12 can preheat the object to be processed to a temperature of 500 ° C. or more, and a main heating chamber (first chamber) 21 for heating the object to be processed to a temperature of 1,000 ° C. or more and 2,400 ° C. or less. And a preheating chamber (second chamber) 22. The preheating chamber 22 is disposed below the main heating chamber 21 and is adjacent to the main heating chamber 21 in the vertical direction. The heating furnace 12 includes a heat insulating chamber (third chamber) 23 disposed below the preheating chamber 22. The heat insulation chamber 23 is adjacent to the preheating chamber 22 in the vertical direction.

The heating furnace 12 includes a vacuum chamber 19, and the main heating chamber 21 and the preheating chamber 22 are provided inside the vacuum chamber 19. A turbo molecular pump 34 as a vacuum forming device is connected to the vacuum chamber 19 so that a vacuum of, for example, 10 ⁻² Pa or less, preferably 10 ⁻⁷ Pa or less can be obtained in the vacuum chamber 19. . A gate valve 25 is interposed between the turbo molecular pump 34 and the vacuum chamber 19. In addition, an auxiliary rotary pump 26 is connected to the turbo molecular pump 34.

  The heating furnace 12 includes a moving mechanism 27 that can move an object to be processed in the vertical direction between the preheating chamber 22 and the main heating chamber 21. The moving mechanism 27 includes a support body 28 that can support an object to be processed, and a cylinder portion 29 that can move the support body 28 up and down. The cylinder portion 29 includes a cylinder rod 30, and one end of the cylinder rod 30 is connected to the support body 28.

  The heating furnace 12 includes a vacuum gauge 31 for measuring the degree of vacuum. Further, the heating furnace 12 is provided with a mass spectrometer 32 for performing mass spectrometry. In the present embodiment, an ion gauge is used as the vacuum gauge 31 and a quadrupole mass spectrometer is used as the mass analyzer 32.

The stock chamber 13 is for temporarily stocking objects to be processed before or after heat treatment in the heating furnace 12, and includes a vacuum chamber 61. The vacuum chamber 61 is provided with a turbo molecular pump 34, a gate valve 25, and a rotary pump 26 as in the heating furnace 12, and is in the vacuum chamber 61, for example, 10 ⁻² Pa or less, preferably 10 ^−7. It is comprised so that the vacuum of Pa or less can be obtained.

  The vacuum chamber 61 is provided with a vacuum gauge 62 for measuring the degree of vacuum. In the present embodiment, an ion gauge is used as the vacuum gauge 62.

  A stocker 63 is provided in the vacuum chamber 61. The stocker 63 is configured so that a plurality of the objects to be processed can be stocked in the vertical direction. The stock chamber 13 includes a moving mechanism 64 for moving the stocker 63 up and down.

  The stock chamber 13 includes a cooling mechanism (not shown) for cooling the workpieces stocked in the stocker 63. This cooling mechanism is constituted by a cooling water path or the like for circulating cooling water.

  The vacuum chamber 19 of the heating furnace 12 and the vacuum chamber 61 of the stock chamber 13 are connected through a transfer path 65. The transport path 65 can be opened and closed by a gate valve 66.

  Further, the stock chamber 13 is provided with a transport mechanism 67 for transporting an object to be processed between the stock chamber 13 and the heating furnace 12. The transport mechanism 67 includes a transport arm 68 that can move in the horizontal direction. The transport mechanism 67 places the object to be processed on the stocker 13 stocker 13 and the support 28 of the heating furnace 12 (preliminary heating) in a state where the object to be processed is placed on the tip of the transport arm 68. It can be conveyed in the horizontal direction between the chamber 22) and the conveyance path 65.

The introduction chamber 14 is for introducing an object to be processed into the high-temperature vacuum furnace 11 from the atmosphere, and includes a vacuum chamber 71. The vacuum chamber 71 is provided with a turbo molecular pump 34, a gate valve 25, and a rotary pump 26 as in the heating furnace 12 and the stock chamber 13, and is preferably 10 ⁻² Pa or less, for example, in the vacuum chamber 71. Is configured such that a vacuum of 10 ⁻⁵ Pa or less can be obtained. The vacuum chamber 71 is provided with a vacuum gauge 72 for measuring the degree of vacuum. In the present embodiment, a combination gauge is used as the vacuum gauge 72.

  A stocker 73 is provided in the vacuum chamber 71. The stocker 73 is configured so that a plurality of the objects to be processed can be stocked in the vertical direction. The introduction chamber 14 includes a moving mechanism 74 for moving the stocker 73 up and down.

  The introduction chamber 14 includes an introduction port 75 for introducing an object to be processed into the vacuum chamber 71. Further, the vacuum chamber 71 of the introduction chamber 14 and the vacuum chamber 61 of the stock chamber 13 are connected through a transfer path 76. The conveyance path 76 can be opened and closed by a gate valve 77.

  The introduction chamber 14 is provided with a transport mechanism 78 for transporting the workpiece. The transport mechanism 78 includes a transport arm 79 that can move in the horizontal direction. The transfer mechanism 78 places the object to be processed between the stocker 73 of the introduction chamber 14 and the stocker 63 of the stock chamber 13 with the object to be processed placed on the tip of the transfer arm 79. It can be conveyed via the conveyance path 76.

  The observation room 15 is for evaluating and observing the object to be processed, and includes a vacuum chamber 81. The vacuum chamber 81 is provided with a vacuum gauge 82 for measuring the degree of vacuum. In this embodiment, an ion gauge is used as the vacuum gauge 82.

  The observation chamber 15 is provided with appropriate observation devices and evaluation devices such as a reflection high-energy electron diffraction device (RHEED) 83. Further, the observation room 15 is provided with a lifting platform 84 on which an object to be processed can be placed. The observation room 15 is provided with a moving mechanism 85 for moving the elevator 84 up and down.

  The vacuum chamber 81 of the observation room 15 and the vacuum chamber 61 of the stock room 13 are connected through a conveyance path 86. The transport path 86 can be opened and closed by a gate valve 87.

  The observation chamber 15 is provided with a transport mechanism 89 for transporting the object to be processed. The transport mechanism 89 includes a transport arm 90 that can move in the horizontal direction. The transfer mechanism 89 places the object to be processed between the lift 84 of the observation chamber 15 and the stocker 63 of the stock chamber 13 while the object to be processed is placed on the tip of the transfer arm 90. Thus, it can be transported via the transport path 86.

  Next, the configuration of the heating furnace 12 will be described with reference to FIGS. FIG. 2 is a sectional view of the heating furnace and the stock chamber, and FIG. 3 is an enlarged sectional view of the heating furnace. 4 is a sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a sectional view taken along line VV in FIG.

  As shown in FIGS. 2 and 3, the main heating chamber 21 is disposed in the upper part of the internal space of the vacuum chamber 19. In addition, as shown in FIG. 4, the main heating chamber 21 is formed in a regular hexagonal shape in a plan sectional view.

  Inside the main heating chamber 21, a mesh heater 33 as a heater is provided. As shown in FIG. 4, the mesh heaters 33 are arranged side by side along the side wall of the main heating chamber 21. The mesh heaters 33 are made of, for example, tungsten, and two mesh heaters 33 are arranged, one for each side of the regular hexagonal main heating chamber 21. The mesh heater 33 is attached to the wall portion of the main heating chamber 21 with an attachment screw made of tantalum subjected to tantalum carbide treatment. With this configuration, the object to be processed disposed in the central portion of the main heating chamber 21 can be heated from the surroundings by the mesh heater 33.

  The mesh heater 33 is covered with an unillustrated cover made of tungsten. This cover is attached to the mesh heater 33 with an attachment screw made of tantalum subjected to tantalum carbide treatment. Accordingly, the cover prevents the mesh heater 33 from being exposed to molecular beams and vapors generated from the object to be processed during the main heat treatment described later, so that the life of the mesh heater 33 can be extended.

  The mesh heater 33 can be removed and replaced together with the outer wall of the main heating chamber 21 for each side (two mesh heaters 33) of the regular hexagonal main heating chamber 21. With this divided configuration, it is possible to replace only the mesh heater 33 that has reached the end of its life, thereby reducing maintenance costs.

  A first multilayer heat reflecting metal plate 41 is fixed to the side wall and ceiling of the main heating chamber 21, and the heat of the mesh heater 33 is reflected toward the center of the main heating chamber 21 by the first multilayer heat reflecting metal plate 41. It is configured to let you.

  As a result, a layout is realized in which the mesh heater 33 is arranged so as to surround the object to be processed as a heat treatment target in the main heating chamber 21 and the multilayer heat reflecting metal plate 41 is arranged on the outer side. Therefore, the workpiece can be heated strongly and evenly, and the temperature can be raised to a temperature of 1,000 ° C. or more and 2,300 ° C. or less.

  The ceiling side of the main heating chamber 21 is closed by a first multilayer heat reflecting metal plate 41, while a through hole 55 is formed in the first multilayer heat reflecting metal plate 41 at the bottom. The object to be processed can move between the main heating chamber 21 and the preheating chamber 22 adjacent to the lower side of the main heating chamber 21 through the through hole 55.

  A part of the support 28 of the moving mechanism 27 is inserted into the through hole 55. The support 28 has a configuration in which a second multilayer heat-reflecting metal plate 42, a third multilayer heat-reflecting metal plate 43, and a fourth multilayer heat-reflecting metal plate 44 are arranged at intervals from each other in order from the top. .

  The three multilayer heat-reflecting metal plates 42 to 44 are all arranged horizontally and are connected to each other by a column portion 35 provided in the vertical direction. A receiving table 36 is disposed in a space between the second multilayer heat reflecting metal plate 42 and the third multilayer heat reflecting metal plate 43, and an object to be processed (precisely, the object to be processed) is placed on the receiving table 36. It is comprised so that the container 2) which accommodated can be mounted. In the present embodiment, the cradle 36 is made of tantalum carbide. Further, the cradle 36 is attached to a member (for example, the third multilayer heat reflecting metal plate 43) constituting the support 28 by an attachment screw made of tantalum subjected to tantalum carbide treatment.

  The cylinder rod 30 of the cylinder part 29 constituting the moving mechanism 27 is formed in a hollow shape. Further, a flange is formed at the end of the cylinder rod 30, and this flange is fixed to the lower surface of the fourth multilayer heat reflecting metal plate 44. With this configuration, the object to be processed (container 2) on the cradle 36 can be moved up and down together with the three multilayer heat reflecting metal plates 42 to 44 by expanding and contracting the cylinder portion 29.

  The preheating chamber 22 is configured by surrounding the space below the main heating chamber 21 with a multilayer heat reflecting metal plate 46. As shown in FIG. 5, the preheating chamber 22 is configured to have a circular shape in plan sectional view. In the preheating chamber 22, no heating means such as the mesh heater 33 is provided.

  As shown in FIGS. 3 and 5, a through hole 56 is formed in the multilayer heat reflecting metal plate 46 at the bottom surface of the preheating chamber 22. Further, in the multilayer heat reflecting metal plate 46 that forms the side wall of the preheating chamber 22, a passage hole 50 is formed in a portion facing the transport path 65. The preheating chamber 22 includes an opening / closing member 51 that can close the passage hole 50, and an opening / closing mechanism 52 that moves the opening / closing member 51 up and down.

  The heat insulating chamber 23 adjacent to the lower side of the preheating chamber 22 is partitioned on the upper side by the multilayer heat reflecting metal plate 46, and on the lower side and the side portion by the multilayer heat reflecting metal plate 47. A through-hole 57 is formed in the multilayer heat reflecting metal plate 47 covering the lower side of the heat insulating chamber 23 so that the cylinder rod 30 can be inserted.

  A housing recess 58 is formed in the multilayer heat reflecting metal plate 47 at a position corresponding to the upper end of the through hole 57. The storage recess 58 can store the fourth multilayer heat-reflecting metal plate 44 provided in the support 28.

  Each of the multilayer heat reflecting metal plates 41 to 44, 46, and 47 has a structure in which metal plates (made of tungsten) are laminated at a predetermined interval. Also in the opening / closing member 51, a multilayer heat reflecting metal plate having the same configuration is used for a portion that closes the passage hole 50.

  In this way, the multilayer heat-reflecting metal plate constructed by laminating high-melting-point metal plates has a heat insulating function and reflects heat radiation energy radiated from the tungsten mesh heater 33, thereby obtaining a heating effect. (Reflection heating function).

  That is, most of the wavelength energy emitted when the tungsten mesh heater 33 is heated (high temperature range of 1,800 ° C. to 2,600 ° C.) is included in the wavelength range of 0.4 μm to 3.5 μm. ing. On the other hand, at 2,200 ° C., the peak of the wavelength energy of tungsten appears at a portion of about 1.1 μm, and the reflectance of tungsten at this time is about 0.65. In addition, tungsten has a reflectance that increases as the wavelength increases in a wavelength region (1.1 μm to 3.0 μm) with relatively high wavelength energy. For example, the reflectance is about 0.8 at a wavelength of 3.0 μm. Reach. Thus, it can be said that tungsten has sufficient reflection characteristics with respect to the tungsten mesh heater 33 in a clean high-purity atmosphere.

  Any material can be used as the material of the multilayer heat-reflecting metal plates 41 to 44, 46, 47 as long as the material has sufficient heating characteristics with respect to the heat radiation of the mesh heater 33 and has a melting point higher than the ambient temperature. Can be used. For example, in addition to tungsten, high melting point metal materials such as tantalum, niobium, molybdenum, and carbides such as tungsten carbide, zirconium carbide, tantalum carbide, hafnium carbide, molybdenum carbide, etc. are used. 46, 47. Further, an infrared reflection film made of gold, tungsten carbide or the like may be further formed on the reflection surface.

  And the multilayer heat | fever reflective metal plates 42-44 with which the support body 28 is equipped are the structures which laminated | stacked the punch metal structure tungsten plate which has many small through-holes at predetermined intervals, varying the position of the said through-hole. It has become.

  Further, the number of stacked second multilayer heat reflecting metal plates 42 provided in the uppermost layer of the support 28 is smaller than the number of stacked first multilayer heat reflecting metal plates 41 in the main heating chamber 21.

  These multilayer heat-reflecting metal plates 41 to 44, 46, and 47 are fixed to wall portions of the main heating chamber 21, the preheating chamber 22, and the like by attachment screws made of tantalum subjected to tantalum carbide treatment. Thus, the mesh heater 33, the cover covering it, the cradle 36, and the multilayer heat-reflecting metal plates 41 to 44, 46, 47 are made of tantalum subjected to tantalum carbide treatment as fixing means for attaching to other members. By using the mounting screw, the screw is not seized at the fixed portion, and the maintenance work can be easily performed.

  In the first multilayer heat-reflecting metal plate 41 provided in the main heating chamber 21, a plurality of thermocouples 37 as temperature detection units are installed between the metal plates to be laminated (see FIG. 4). reference). Thereby, the temperature distribution in the main heating chamber 21 can be accurately grasped and the mesh heater 33 can be feedback-controlled. Accordingly, it is possible to control the temperature of the main heating chamber 21 to be accurately raised or lowered according to a preset temperature profile. Compared with temperature detection control using a conventional radiation thermometer and viewport, temperature measurement is not impossible due to clouding of the viewport of the chamber, and highly reliable temperature control can be realized.

  Next, with reference to FIG. 7 and the like, the container 2 used for storing an object to be processed in the high temperature vacuum furnace 11 will be described. FIG. 7 is a perspective view of the container with the upper and lower containers removed. FIG. 8 is a schematic cross-sectional view showing a state in which the workpiece is set in the container.

  The container 2 is configured by fitting an upper container 2a and a lower container 2b having the configuration shown in FIG. In the present embodiment, the container 2 is configured in a cylindrical shape, but this is an example, and may be configured in a hexahedral shape, for example.

  The upper container 2a and the lower container 2b are made of tantalum subjected to tantalum carbide treatment. As a result, a tantalum carbide layer 3 is formed on the surface of the container 2 as shown in FIG. A portion of the tantalum carbide layer 3 that covers the inner surfaces of the upper container 2 a and the lower container 2 b is exposed in the internal space of the container 2.

  In the internal space of the container 2, a single crystal SiC substrate 1 as a processing target (object to be processed) is arranged. As a crystal structure of the single crystal SiC substrate 1, for example, 6H—SiC or 4H—SiC may be considered. Further, inside the container 2, silicon pellets 5 as a Si supply source are arranged.

  A spacer 4 is interposed between the single crystal SiC substrate 1 and the inner bottom surface of the lower container 2b. With the spacer 4, both the upper surface and the lower surface of the single crystal SiC substrate 1 are sufficiently exposed to the internal space of the container 2.

  The play of the fitting portion when the upper container 2a and the lower container 2b are fitted together as shown in FIG. 8 is preferably about 2 mm or less. As a result, a substantially sealed state is realized, and in the heat treatment process in the main heating chamber 21, the Si pressure in the container 2 is increased to a pressure higher than the external pressure (pressure in the main heating chamber 21). Intrusion into the container 2 through the fitting portion can be prevented.

  The container 2 having the above configuration is put into the vacuum chamber 71 through the introduction port 75 of the introduction chamber 14 shown in FIG. 1 and placed on the stocker 73. Then, the turbo molecular pump 34 is driven from this state, and the inside of the vacuum chamber 71 is evacuated.

Note that the vacuum chamber 19 of the heating furnace 12 and the vacuum chamber 61 of the stock chamber 13 are previously set to a vacuum state of 10 ⁻² Pa or less, preferably 10 ⁻⁷ Pa or less. Alternatively, a rare gas atmosphere in which an inert gas is introduced after reaching a vacuum of 10 ⁻² Pa or less, preferably 10 ⁻⁷ Pa or less in advance may be used. Further, the moving mechanism 27 of the heating furnace 12 is driven in advance to keep the support 28 lowered. Further, the opening / closing mechanism 52 is driven to lower the opening / closing member 51 to open the passage hole 50 of the preheating chamber 22.

  Next, the gate valve 77 of FIG. 1 is opened, the transfer mechanism 78 is driven, the container 2 in the introduction chamber 14 is transferred onto the stocker 63 of the stock chamber 13, and then the gate valve 77 is closed. Next, the gate valve 66 is opened, the transport mechanism 67 is driven, the container 2 is transported into the preheating chamber 22 (on the cradle 36 provided in the support 28), and then the gate valve 66 is closed. As described above, by providing the passage hole 50 in the multilayer heat reflecting metal plate 46 provided on the side wall of the preheating chamber 22, the container 2 can be taken in and out of the preheating chamber 22 with a simple configuration.

  Next, the opening / closing mechanism 52 is driven to raise the opening / closing member 51 and close the passage hole 50. In this state, as shown in FIG. 3, the second multilayer heat-reflecting metal plate 42 of the support 28 closes the through hole 55 and is positioned so as to partition the preheating chamber 22 and the main heating chamber 21. Further, the third multilayer heat reflecting metal plate 43 closes the through hole 56 and is positioned so as to partition the preheating chamber 22 and the heat insulating chamber 23. Further, the fourth multilayer heat reflecting metal plate 44 is positioned so as to close the through hole 57 and the housing recess 58 and partition the heat insulating chamber 23 from the outside space.

  When the mesh heater 33 is driven in this state, the main heating chamber 21 is heated to a predetermined temperature of 1,000 ° C. or more and 2,400 ° C. or less. Here, the number of laminated second multilayer heat reflecting metal plates 42 of the support 28 is smaller than the number of laminated first multilayer heat reflecting metal plates 41. Accordingly, a part of the heat generated by the mesh heater 33 is appropriately supplied (distributed) to the preheating chamber 22 via the second multilayer heat reflecting metal plate 42, and the container 2 (object to be processed) in the preheating chamber 22 is supplied. Can be preheated to a predetermined temperature of, for example, 500 ° C. or higher. That is, preheating can be realized without installing a heater in the preheating chamber, and a simple structure of the preheating chamber can be realized.

  At this time, the third multilayer heat reflecting metal plate 43 closes the lower through-hole 56 of the preheating chamber 22, and the third multilayer heat reflecting metal plate 43 is a laminated structure of punch metal plates as described above. It has become. Similarly, the fourth multilayer heat reflecting metal plate 44 that closes the lower through-hole 57 of the heat insulation chamber 23 has a laminated structure of punch metal plates.

  Therefore, heat can be favorably reflected by the portion of the third multilayer heat reflecting metal plate 43, and the object to be processed in the preheating chamber 22 can be efficiently preheated and degassed. Further, the gas emitted from the object to be processed in the container 2 during the preheating passes through the punch metal through-holes of the third multilayer heat reflecting metal plate 43 and the fourth multilayer heat reflecting metal plate 44 and the preheating chamber 22 and the heat insulating chamber 23. Can be easily exhausted to the outside.

  Furthermore, since the passage hole 50 is closed by the opening / closing member 51 during the preheating, the heat loss of the preheating chamber 22 can be reduced. Further, the cylinder rod 30 connected to the fourth multilayer heat reflecting metal plate 44 of the support 28 is located on the opposite side of the preheating chamber 22 with the heat insulating chamber 23 interposed therebetween. Therefore, the heat loss of the preheating chamber 22 and the like that escapes through the cylinder rod 30 can be effectively reduced by the heat insulating chamber 23, and thermal damage to the cylinder rod 30 can be prevented.

  After performing the above-mentioned preheating process for a predetermined time, the cylinder part 29 is driven and the support body 28 is raised. As a result, as shown in FIG. 6, the container 2 (and the object to be processed inside) passes through the through hole 55 from the lower side and moves into the main heating chamber 21. Thereby, the main heat treatment is started immediately, and the container (object to be processed) in the main heating chamber 21 can be rapidly heated to a predetermined temperature (a temperature of 1,000 ° C. or more and 2,400 ° C. or less). .

  In the state of FIG. 6, the third multilayer heat reflecting metal plate 43 of the support 28 is positioned so as to close the through hole 55 and partition the preheating chamber 22 and the main heating chamber 21. Therefore, the object to be processed in the main heating chamber 21 can be efficiently preheated. In addition, since the fourth multilayer heat reflecting metal plate 44 of the support 28 closes the through hole 56, it is possible to prevent heat from escaping from the preheating chamber 22 and realize efficient heating in the main heating chamber 21. Yes. Further, since the fourth multilayer heat reflecting metal plate 44 has a punch metal structure like the third multilayer heat reflecting metal plate 43, the gas can be exhausted well to the outside of the preheating chamber 22.

  After performing the main heating process for a predetermined time, the heating by the mesh heater 33 is stopped and the moving mechanism 27 is driven to lower the support 28. As a result, as shown in FIG. 3, the container 2 moves into the preheating chamber 22 and is rapidly cooled. After cooling for a predetermined time in this state, after the opening / closing member 51 and the gate valve 66 are opened, the transport mechanism 67 of FIG. 1 is driven, and the container 2 on the cradle 36 is transported onto the stocker 63 of the stock chamber 13. The gate valve 66 is closed.

  The treated container 2 is further cooled in the stock chamber 13 by a cooling mechanism (not shown) and then transferred to the observation chamber 15 for evaluation and observation, or transferred to the introduction chamber 14 and taken out from the introduction port 75. And sent to the next process.

  FIG. 9 shows the temperature change of the object to be processed in the above process. As shown in this graph, it can be seen that the container 2 moves from the preheating chamber 22 to the main heating chamber 21 and the main heating process is started, and at the same time, the workpiece is heated with a rapid temperature rise curve.

  In this main heat treatment, the internal space of the container 2 is kept at the silicon saturated vapor pressure by the evaporation of silicon vapor from the silicon pellet 5 installed inside the container 2 (FIG. 8). The evaporation of silicon molecules from the surface of 1 is suppressed. Further, since the tantalum carbide layer 3 is exposed in the internal space of the container 2, only carbon molecules are evaporated from the silicon vapor and the carbon vapor existing in the internal space of the container 2 by evaporating from the single crystal SiC substrate 1. It is selectively taken into the tantalum carbide layer 3 on the surface of the container 2.

  As a result, the internal space of the container 2 is maintained in an atmosphere in which silicon vapor hardly evaporates from the surface of the single crystal SiC substrate 1 while carbon vapor easily evaporates. As a result, silicon vapor and carbon vapor are evaporated almost simultaneously from the surface of the single crystal SiC substrate 1. In addition, since carbon molecules are selectively taken into the tantalum carbide layer 3 on the surface of the container 2, the internal space of the container 2 is always kept at a high silicon vapor pressure and is automatically kept at the silicon saturated vapor pressure. By the above, the surface of the single crystal SiC substrate 1 can be made into a very flat surface which is not roughened by silicon evaporation.

  According to the high temperature vacuum furnace 11 of the present embodiment, a sharp temperature rising curve as shown in FIG. 9 is realized and the single crystal SiC substrate 1 can be heated uniformly.

  That is, the example of the temperature control and the conveyance control of the object to be processed shown in FIG. Specifically, the process shown in FIG. 9 is performed as follows. That is, the object to be processed is carried into the preheating chamber 22 and preheated to a temperature of 500 ° C. or more and 1,000 ° C. or less (preheating treatment). And while moving a to-be-processed object from the preheating chamber 22 to the said main heating chamber 21, while maintaining the main heating chamber 21 at the arbitrary temperature of 1,000 degreeC or more and 2,400 degrees C or less, it is a sharp temperature gradient. The object to be processed is rapidly heated to an arbitrary temperature between 1,000 ° C. and 2,400 ° C. (main heating process). After the main heating is completed, the object to be processed is moved from the main heating chamber 21 to the preheating chamber 22, thereby cooling the object to be processed with a sharp temperature gradient (cooling process).

  Note that heat treatment for increasing or decreasing the temperature of an object to be processed with such a rapid temperature gradient can be applied to various heat treatments. For example, a single crystal SiC substrate as an object to be processed is placed in a state where a polycrystalline SiC substrate is very close to the surface of the substrate, and is stored in a tantalum carbide crucible (container), and in the preheating chamber 22, for example, 800 ° C. Preheat to. Thereafter, the crucible is moved to the main heating chamber 21 to make the inside of the crucible into a silicon saturated vapor pressure atmosphere and heated to, for example, 2,000 ° C. in a few minutes. When the heat treatment is performed for about 10 minutes at the temperature of 2,000 ° C., a single crystal SiC thin film can be vapor-phase epitaxially grown on the surface of the single crystal SiC substrate. Thereafter, the crucible is moved from the main heating chamber 21 to the preheating chamber 22 to be rapidly cooled, and then carried out of the heating furnace 12. When performing such a vapor phase process, which should be referred to as an ultra-close proximity sublimation method, if the high-temperature vacuum furnace 11 of the present embodiment is used to perform heating in the short time and cooling in the short time as described above, there is no defect. This single crystal SiC thin film can be obtained in a short time and is extremely suitable.

  As another heat treatment, for example, a single crystal SiC substrate is accommodated in a tantalum carbide crucible (container) and preheated to, for example, 800 ° C. in the preheating chamber 22. Thereafter, by moving the crucible to the main heating chamber 21, the inside of the crucible is made into a silicon saturated vapor pressure atmosphere, and when the heat treatment is performed at a temperature of, for example, 2,000 ° C. for about 10 minutes, the surface of the single crystal SiC substrate is thermally etched, The substrate surface can be planarized at the atomic level. Thereafter, the crucible is moved from the main heating chamber 21 to the preheating chamber 22 to be rapidly cooled, and then carried out of the heating furnace 12. In such a gas phase process, it is preferable to perform the high-temperature heating in a short time and the cooling in a short time as described above using the high-temperature vacuum furnace 11 of the present embodiment. As a result, the surface modification of the single crystal SiC substrate can be efficiently performed by thermal etching, and the quality of the surface modification is flat at the atomic level as described above, and a more uniform morphology is formed. The surface state can be made extremely good. As a result, for example, a mechanical chemical polishing (CMP) process can be eliminated.

  However, instead of rapidly increasing the temperature by moving the object to be processed to the main heating chamber 21, heat treatment may be performed in the following manner. That is, after the object to be processed is moved from the preheating chamber 22 to the main heating chamber 21, the temperature of the main heating chamber 21 is controlled according to the set temperature profile so that the object to be processed is 1,000 ° C. or more. Heat to a temperature below 400 ° C. Further, after the main heating process is finished, the temperature of the main heating chamber 21 is controlled in accordance with the set temperature profile so that the object to be processed in the main heating chamber 21 is cooled. The cooling is performed in the main heating chamber 21 according to a predetermined temperature profile up to a certain temperature, and then the second cooling process is performed by moving the workpiece to the preheating chamber 22. Also good.

  For example, a silicon plate interposed between the surface of a single crystal SiC substrate and a polycrystalline SiC substrate is accommodated in a crucible (container) made of tantalum carbide and preheated to, for example, 800 ° C. in the preheating chamber 22. . Subsequently, the crucible is moved to the main heating chamber 21. Thereafter, according to a predetermined temperature profile, the temperature of the main heating chamber 21 is increased over a period of about 1 hour, and after reaching 2,000 ° C., a high temperature treatment is performed for about 10 hours. Then, the inside of the crucible becomes a silicon saturated vapor pressure atmosphere, and the silicon melt is interposed between the single crystal SiC substrate and the polycrystalline SiC substrate, and the single crystal SiC is liquid phase epitaxially grown on the surface of the single crystal SiC substrate. Can do. Thereafter, according to a predetermined temperature profile, the temperature of the main heating chamber 21 is lowered over a period of about 1 hour, and when it reaches 800 ° C., it is moved to the preheating chamber 22 and carried out of the heating furnace 12. To do. When such a liquid phase process is performed, it is possible to set a temperature profile with a gentle temperature gradient in the high-temperature vacuum furnace 11 of the present embodiment, and to heat and cool the workpiece over a long period of time. This is extremely effective in that the distortion of the liquid phase epitaxial growth film can be prevented.

  Although the preferred embodiment of the present invention has been described above, the above configuration can be modified as follows, for example.

  FIG. 10 shows a schematic diagram of an example of a heating furnace. In the following description, members that are the same as or similar to those in the above-described embodiment are given the same reference numerals, and descriptions thereof are omitted.

  In the heating furnace 12 shown in FIG. 10, the tip end of the cylinder rod 30 is connected to the fourth multilayer heat reflecting metal plate 44 located at the lower end of the support 28 via a temperature insulator 38. With this configuration, the temperature insulator 38 can reduce the loss of heat from the main heating chamber 21 and the preheating chamber 22 that travels through the cylinder rod 30 and escapes.

  Although not shown in FIG. 3 and the like, as shown in FIG. 10, in the main heating chamber 21, a shield 39 is provided around the position of the object to be processed (container 2) during the main heat processing. Also good. The shield 39 is made of, for example, tungsten, molybdenum, or tantalum, and is formed in a cylindrical shape. According to this configuration, the mesh heater 33 is prevented from being exposed to the molecular beam or gas generated from the object to be processed during the main heat treatment, so that the life of the mesh heater 33 can be extended. The shield 39 may be provided on the support 28 side of the moving mechanism 27 (movable together with the object to be processed). In this case, the same effect as described above can be exhibited. In order to attach the shield 39 to another member, it is preferable to use an attachment screw made of tantalum carbide-treated tantalum in terms of preventing seizure in a high temperature environment.

  FIG. 11 shows a schematic diagram of another example of the heating furnace. In the heating furnace 12 of FIG. 11, a second heat insulating chamber (fourth chamber) 24 is further disposed below the heat insulating chamber 23. The upper side of the second heat insulation chamber 24 is covered with a multilayer heat reflecting metal plate 47, and the side portion and the lower side thereof are covered with a multilayer heat reflecting metal plate 48. The support 28 of the moving mechanism 27 further includes a fifth multilayer heat reflecting metal plate 45 having a punch metal structure below the fourth multilayer heat reflecting metal plate 44. The fifth multilayer heat reflecting metal plate 45 is movable together with the object to be processed, like the other multilayer heat reflecting metal plates 42 to 44. The cylinder rod 30 is connected to the fifth multilayer heat reflecting metal plate 45 via a temperature insulator 38.

  FIG. 11 shows a state during the preheating process. At this time, the through holes 59 formed in the multilayer heat-reflecting metal plate 47 are closed by the fourth multilayer heat-reflecting metal plate 44 provided in the support body 28 to insulate the heat. The chamber 23 and the second heat insulating chamber 24 are separated by a fourth multilayer heat reflecting metal plate 44. Further, the through hole 57 and the housing recess 58 formed in the multilayer heat reflecting metal plate 48 are closed by the fifth multilayer heat reflecting metal plate 45 provided in the support 28, so that the second heat insulating chamber 24 and the space outside thereof are closed. Are separated by a fifth multilayer heat reflecting metal plate 45. Therefore, the closed state of the heat insulation chamber 23 and the second heat insulation chamber 24 is realized at the time of preheating, and the thermal efficiency is further improved by the heat insulation effect of the two heat insulation chambers.

  Further, during the main heat treatment in which the support 28 is raised from the state of FIG. 11, the through hole 56 of the multilayer heat reflective metal plate 46 is closed by the fourth multilayer heat reflective metal plate 44, and The through hole 59 is closed by the fifth multilayer heat reflecting metal plate 45. Therefore, in the configuration shown in FIG. 11, the heat insulation chamber 23 is closed even during the main heat treatment, and the heat efficiency can be further increased by the heat insulation effect. Further, since the cylinder rod 30 is located on the opposite side of the preheating chamber 22 with the heat insulating chamber 23 interposed during the main heat treatment, the thermal damage of the cylinder rod 30 can be effectively prevented.

  Instead of the configuration in which the passage hole 50 is provided in the preheating chamber 22, for example, the following configuration can be adopted. That is, the multilayer heat reflecting metal plate 46 of the preheating chamber 22 is divided into, for example, the horizontal direction (or the up and down direction), and a part or all of the divided parts moves so that there is a gap between the multilayer heat reflecting metal plates 46. (Passage space) can be formed. In this case, the workpiece can be taken in and out of the preheating chamber 22 through the passage space.

  The conveyance mechanism for taking in and out the object (container 2) to / from the preheating chamber 22 is not limited to the one using the conveyance arm 68. For example, it can be changed to a rotary table type transport mechanism having a horizontal rotary table.

  When the object to be processed (container 2) is in the main heating chamber 21, the tip of the cylinder rod 30 can be separated from the support 28. Before the cylinder rod 30 is cut off, the support 28 is held on the main heating chamber 21 side by an appropriate mechanism. According to this configuration, heat loss through the cylinder rod 30 and thermal damage to the cylinder rod 30 can be significantly suppressed.

  The cradle 36 can be modified to be made of, for example, tungsten carbide, tungsten, or graphite instead of being made of tantalum carbide.

  The mesh heater 33 can be changed to be made of, for example, molybdenum or tantalum instead of being made of tungsten.

  A cover (not shown) covering the mesh heater 33 can be changed to be made of molybdenum or tantalum, for example, instead of being made of tungsten.

  The container 2 used in the heat treatment may be changed to be made of tantalum carbide, tantalum carbide (without tantalum carbide treatment), tungsten carbide, tungsten, or graphite, for example, instead of being composed of tantalum carbide-treated tantalum. it can.

  The heat treatment of the above embodiment is not limited to the heat treatment related to the single crystal SiC substrate 1 but can be used to cause other various chemical changes and physical changes to be processed.

The schematic diagram which shows the whole high-temperature vacuum furnace structure which concerns on one Embodiment of this invention. Sectional drawing which shows the structure of a heating furnace and a stock chamber. The cross-sectional enlarged view which shows a mode that the container which accommodated to-be-processed object is moved to a preheating chamber, and the preheating process is performed in a heating furnace. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a cross-sectional view taken along line VV in FIG. 3. The cross-sectional enlarged view which shows a mode that the container is moved to the main heating chamber from the state of FIG. 3, and this heat processing is performed. The perspective view which shows the state which removed the upper container and lower container of the container used for heat processing. Sectional drawing which shows the example of arrangement | positioning of the to-be-processed object in a container. The graph which shows the example of the temperature control of preheating processing and this heat processing, and the movement of a to-be-processed object. The schematic cross section which shows a mode that a preheating process is performed in the other example of a heating furnace. The schematic cross section which shows a mode that a preheating process is performed in the further another example of a heating furnace.

Explanation of symbols

1 Single crystal SiC substrate (sample, workpiece)
2 Vessel 11 High-temperature vacuum furnace (heat treatment equipment)
12 Heating furnace 13 Stock room 19 Vacuum chamber 21 Heating room (first room)
22 Preheating room (2nd room)
23 Insulation room (third room)
24 Second heat insulation room (4th room)
27 Moving Mechanism 28 Supporting Base 29 Cylinder Unit 30 Cylinder Rod 33 Mesh Heater (Heating Heater)
41 1st multilayer heat reflecting metal plate 42 2nd multilayer heat reflecting metal plate 43 3rd multilayer heat reflecting metal plate 44 4th multilayer heat reflecting metal plate 45 5th multilayer heat reflecting metal plate 46-48 multilayer heat reflecting metal plate

Claims (42)

A first chamber for heating the workpiece to a temperature of 1,000 ° C. or more and 2,400 ° C. or less;
A second chamber adjacent to the first chamber;
A moving mechanism for moving the object to be processed between the second chamber and the first chamber;
With
Inside the first chamber, a heater arranged to heat the object to be processed from the surroundings, and a first multilayer arranged to reflect the heat of the heater toward the object to be processed A heat reflecting metal plate,
The moving mechanism includes a second multilayer heat-reflecting metal plate that can move with the object to be processed,
When the object to be processed is in the second chamber, the second multilayer heat reflecting metal plate is positioned so as to separate the first chamber and the second chamber, and a part of the heat generated from the heater is generated. A heat treatment apparatus, wherein the heat treatment apparatus is configured to be supplied to the second chamber through the second multilayer heat-reflecting metal plate and thereby to preheat the object to be processed in the second chamber. The heat treatment apparatus according to claim 1,
The heat treatment apparatus characterized in that the number of laminated layers of the second multilayer heat reflecting metal plates is smaller than the number of laminated layers of the first multilayer heat reflecting metal plates. The heat treatment apparatus according to claim 1 or 2,
The moving mechanism includes a third multilayer heat reflecting metal plate movable with the object to be processed,
When the object to be processed is in the second chamber, the third multilayer heat-reflecting metal plate is positioned so as to separate the second chamber from the outside thereof.
A heat treatment apparatus, wherein the third multilayer heat reflecting metal plate is positioned so as to separate the first chamber and the second chamber when the object to be processed is in the first chamber. The heat treatment apparatus according to claim 3,
The third multilayer heat-reflecting metal plate is formed by laminating metal plates having a large number of through-holes while varying the positions of the through-holes. The heat treatment apparatus according to claim 3 or 4,
The moving mechanism includes a fourth multilayer heat-reflecting metal plate movable with the object to be processed,
The heat treatment apparatus, wherein when the object to be processed is in the first chamber, the fourth multilayer heat reflecting metal plate is positioned so as to separate the second chamber from the outside. The heat treatment apparatus according to claim 3 or 4,
A third chamber surrounded by a multilayer heat-reflecting metal plate is provided adjacent to the outside of the second chamber;
The second chamber is vertically adjacent to the first chamber;
The third chamber is vertically adjacent to the second chamber,
The moving mechanism includes a fourth multilayer heat-reflecting metal plate movable with the object to be processed,
The heat treatment apparatus, wherein the fourth multilayer heat reflecting metal plate is positioned so as to separate the second chamber and the third chamber when the object to be processed is in the first chamber. The heat treatment apparatus according to claim 6,
The heat treatment apparatus, wherein when the object to be processed is in the second chamber, the fourth multilayer heat-reflecting metal plate is positioned so as to separate the third chamber from the outside. The heat treatment apparatus according to claim 7,
A rod is connected to the fourth multilayer heat reflecting metal plate,
The rod is located on the opposite side of the second chamber across the third chamber when the workpiece is in the second chamber. A heat treatment apparatus according to any one of claims 5 to 8,
The fourth multilayer heat-reflecting metal plate is formed by laminating metal plates having a large number of through holes while varying the positions of the through holes. The heat treatment apparatus according to claim 6 or 7,
The moving mechanism includes a fifth multilayer heat reflecting metal plate movable with the object to be processed,
When the object to be processed is in the first chamber, the fifth multilayer heat reflecting metal plate is positioned so as to separate the third chamber from the outside. The heat treatment apparatus according to claim 10,
A fourth chamber surrounded by a multilayer heat-reflecting metal plate is provided adjacent to the outside and the lower side of the third chamber;
An apparatus for heat treatment, wherein when the object to be processed is in the second chamber, the fifth multilayer heat-reflecting metal plate is positioned so as to separate the fourth chamber from the outside. The heat treatment apparatus according to claim 11,
A rod is connected to the fifth multilayer heat reflecting metal plate,
The rod is located on the opposite side of the second chamber across the third chamber when the workpiece is in the first chamber. The heat treatment apparatus according to any one of claims 1 to 12,
A heat treatment apparatus characterized in that the object to be treated in the second chamber can be preheated to a temperature of 500 ° C. or higher. A heat treatment apparatus according to any one of claims 1 to 13,
The moving mechanism includes a support that supports the object to be processed, and a rod that is coupled to the support.
The heat treatment apparatus according to claim 1, wherein the rod is connected to the support through a temperature insulator. The heat treatment apparatus according to any one of claims 1 to 14,
The moving mechanism includes a support that supports the object to be processed, and a rod that is coupled to the support.
A heat treatment apparatus configured to be capable of releasing the connection between the rod and the support when the object to be processed is in the first chamber. The heat treatment apparatus according to claim 15,
The second chamber is provided with a multilayer heat reflecting metal plate, and a passage hole is formed in the multilayer heat reflecting metal plate, and an object to be processed can be taken in and out of the second chamber through the passage hole. Heat treatment equipment.   The heat treatment apparatus according to claim 16, wherein an opening / closing member capable of opening and closing the passage hole is provided. The heat treatment apparatus according to claim 14,
The second chamber includes a multilayer heat reflecting metal plate, and is configured to be able to form a passage space by moving at least a part of the multilayer heat reflecting metal plate.
A heat treatment apparatus characterized in that a workpiece can be taken in and out of the second chamber through the passage space. A heat treatment apparatus according to any one of claims 1 to 18,
A transport mechanism capable of loading and unloading an object to and from the second chamber;
The transport mechanism includes an arm, and is configured to transport an object to be processed by the arm. The heat treatment apparatus according to any one of claims 1 to 19,
A transport mechanism capable of loading and unloading an object to and from the second chamber;
A heat treatment apparatus characterized in that the transport mechanism is configured as a rotary table. A heat treatment apparatus according to any one of claims 1 to 20,
A stock room capable of stocking a plurality of workpieces in a vertical direction; and
A transport mechanism capable of transporting a workpiece in a horizontal direction between the second chamber and the stock chamber;
With
The heat treatment apparatus, wherein the second chamber is adjacent to the first chamber in a vertical direction. The heat treatment apparatus according to claim 21, wherein
The heat treatment apparatus, wherein the stock chamber includes a cooling mechanism for cooling an object to be processed stocked in the stock chamber. The heat treatment apparatus according to any one of claims 1 to 22,
Provided with an introduction chamber for introducing workpieces from the atmosphere into the equipment,
A heat treatment apparatus configured to be capable of transporting an object to be treated introduced into the introduction chamber to the second chamber. The heat treatment apparatus according to any one of claims 1 to 23,
The heat treatment apparatus is characterized in that the first chamber is configured to be able to be a vacuum of 10 ⁻² Pa or less. The heat treatment apparatus according to any one of claims 1 to 23,
The heat treatment apparatus is characterized in that the first chamber is configured to be in a rare gas atmosphere into which an inert gas is introduced after reaching a vacuum of 10 ⁻² Pa or less. The heat treatment apparatus according to any one of claims 1 to 25,
The moving mechanism includes a cradle for placing the object to be processed,
The cradle is made of at least one of tantalum carbide, tungsten carbide, tungsten, tantalum, molybdenum, or graphite. The heat treatment apparatus according to claim 26,
The heat treatment apparatus, wherein the cradle is fixed to another member by a fixing screw made of tantalum subjected to tantalum carbide treatment. A heat treatment apparatus according to any one of claims 1 to 27,
The heating heater is made of at least one of tungsten, molybdenum, and tantalum. The heat treatment apparatus according to claim 28, wherein
The said heater is fixed to the other member with the attachment screw which consists of a tantalum which performed the tantalum carbide process, The heat processing apparatus characterized by the above-mentioned. A heat treatment apparatus according to any one of claims 1 to 29,
The heat treatment apparatus is characterized in that the heater is covered with a cover made of at least one of tungsten, molybdenum, and tantalum. The heat treatment apparatus according to claim 30, wherein
The heat treatment apparatus, wherein the cover is fixed to another member by a mounting screw made of tantalum subjected to tantalum carbide treatment. The heat treatment apparatus according to any one of claims 1 to 31,
The heat treatment apparatus, wherein the first multilayer heat reflective metal plate and the second multilayer heat reflective metal plate are made of at least one of tungsten carbide, tungsten, tantalum, and molybdenum. A heat treatment apparatus according to claim 32, wherein
At least one of the first multilayer heat-reflecting metal plate and the second multilayer heat-reflecting metal plate is fixed to another member by a mounting screw made of tantalum carbide-treated tantalum. . A heat treatment apparatus according to any one of claims 1 to 33,
In the moving mechanism, a heat treatment apparatus is characterized in that a shield made of at least one of tungsten, molybdenum, and tantalum is disposed around an object to be processed. A heat treatment apparatus according to claim 34,
The heat treatment apparatus, wherein the shield is fixed to another member by a mounting screw made of tantalum subjected to tantalum carbide treatment. A heat treatment apparatus according to any one of claims 1 to 35, wherein
In the first multilayer heat-reflecting metal plate, a temperature detecting unit is disposed between the stacked metal plates. A heat treatment method for heat-treating an object to be treated using the heat treatment apparatus according to any one of claims 1 to 36,
A preheating treatment in which the object to be treated is preheated to a temperature of 500 ° C. or more and 1,000 ° C. or less in the second chamber;
A main heat treatment for heating the object to be processed to a temperature of 1,000 ° C. or more and 2,400 ° C. or less in the first chamber by moving the object to be processed from the second chamber to the first chamber;
A cooling process for cooling the object to be processed by moving the object to be processed from the first chamber to the second chamber after the end of the main heat treatment;
The heat processing method characterized by performing. A heat treatment method for heat-treating an object to be treated using the heat treatment apparatus according to any one of claims 1 to 36,
A preheating treatment in which the object to be treated is preheated to a temperature of 500 ° C. or more and 1,000 ° C. or less in the second chamber;
After the workpiece is moved from the second chamber to the first chamber, the temperature of the first chamber is controlled in accordance with a set temperature profile, so that the workpiece is 1,000 ° C. or more and 2,400 ° C. A main heat treatment for heating to the following temperature;
After the completion of the main heating process, by controlling the temperature of the first chamber according to a set temperature profile, a cooling process for cooling the object to be processed in the first chamber;
The heat processing method characterized by performing. A heat treatment method according to claim 37 or 38,
The heat treatment method, wherein the preliminary heat treatment and the main heat treatment are performed in a vacuum of 10 ⁻² Pa or less. A heat treatment method according to claim 37 or 38,
The preheating treatment and the main heating treatment are performed in a dilute gas atmosphere into which an inert gas is introduced after reaching a vacuum of 10 ⁻² Pa or less. The heat treatment method according to claim 39 or 40,
The preliminary heat treatment and the main heat treatment are performed in a state in which the object to be processed is accommodated in a container composed of an upper container and a lower container, and the upper container and the lower container are fitted with each other.
The container is made of tantalum subjected to tantalum carbide treatment. The heat treatment method according to claim 39 or 40,
The preliminary heat treatment and the main heat treatment are performed in a state in which the object to be processed is accommodated in a container composed of an upper container and a lower container, and the upper container and the lower container are fitted with each other.
The container is made of at least one of tungsten carbide, tungsten, or graphite.

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