Ultrahigh-temperature heat treatment device

Abstract

The present invention relates to an ultra-high temperature heat treatment apparatus, characterized by comprising: a cylindrical heater made of a tungsten material; and a tube made of a material having heat resistance to ultra-high temperatures, the heater being made of a mesh structure.

Description

Technical Field

[0001] The present invention relates to an ultra-high temperature heat treatment device, and more specifically, to an ultra-high temperature heat treatment device comprising a cylindrical heater of metal tungsten material for a grid type vertical process, a thermocouple and a pyrometer based on a temperature change operation mode, and a tube of graphite material, wherein the cylindrical heater is connected to a plurality of electrodes, and cooling water flows around the plurality of electrodes to prevent overheating. Background Art

[0002] Recently, in the production of semiconductors, semiconductors produced by processes using silicon carbide (SiC) have attracted attention because of their higher performance and durability than those produced by processes using silicon (Si).

[0003] However, in order to induce denaturation and property changes of the thin film in the semiconductor process, a heat treatment (Annealing) process is required. The heat treatment process for SiC components is different from the process for existing Si components. It requires an oxidation (Oxidation) process above 1500 degrees and an ultra-high temperature activation (Activation) process above 1900 degrees, which cannot be achieved using the structure used in the existing heat treatment process for Si components.

[0004] Therefore, the present disclosure aims to provide a vertical ultra-high temperature heat treatment device capable of performing ultra-high temperature processes.

[0005] Japanese Patent Document "JP 2007-168708" discloses a heat treatment apparatus and a heat treatment method. Summary of the invention

[0006] Technical issues

[0007] The present invention may have the following objects.

[0008] An object of the present invention is to provide a device for heat treatment of SiC wafers, which is composed of materials and structures capable of processing under ultra-high temperature conditions (above 1900 degrees).

[0009] Furthermore, an object of the present invention is to effectively measure and control ultra-high temperature by changing the operation of a thermocouple according to a change in temperature.

[0010] Furthermore, the present invention aims to control the vacuum by designing the vacuum forming structure inside / outside the tube to prevent oxidation.

[0011] Technical Solution

[0012] An ultra-high temperature heat treatment device for solving the above-mentioned technical problems is characterized in that it comprises: a cylindrical heater made of tungsten material; and a tube made of a material resistant to ultra-high temperatures, wherein the heater is made of a mesh structure.

[0013] As an embodiment, it is characterized in that the heater of the grid structure is divided into a plurality of parts, and a guide part is respectively installed on one side of each of the plurality of parts, and the plurality of guide parts are respectively connected to corresponding electrodes.

[0014] As an embodiment, it is characterized in that the heater is divided into three arc-shaped parts, and the three parts include a first part, a second part and a third part. A thermocouple located between the first part and the second part and a pyrometer located between the second part and the third part measure the internal temperature of the heater.

[0015] As an embodiment, it is characterized in that when the internal temperature of the heater reaches a preset temperature, the thermocouple located inside the heater moves and is located outside the heater.

[0016] As an embodiment, it is characterized in that the tube is made of graphite material.

[0017] As an embodiment, it is characterized by comprising: a vacuum pump, which sucks air inside and outside the tube, and when the heater reaches a preset temperature, the vacuum pump is operated to make the inside and outside of the tube in a vacuum state.

[0018] Technical Effects

[0019] As described above, according to the present invention, the following effects are achieved.

[0020] According to the present invention, there is provided an effect of providing a device, which is composed of a material capable of being processed under ultra-high temperature conditions (above 1900 degrees) for heat treatment of SiC wafers. For example, according to one embodiment of the present invention, the heater is composed of a metal tungsten material, so it does not melt even at ultra-high temperatures and is stable; and it is configured as a grid structure, so that the uniformity of the heat treatment can be improved. In addition, by the cooling structure around the electrode around the power supply unit, short circuits and fires caused by overheating can be prevented.

[0021] Furthermore, according to the present invention, there is an effect of effectively measuring and controlling an ultra-high temperature by changing the operation of the thermocouple according to the change in temperature.

[0022] Furthermore, according to the present invention, there is an effect of controlling the vacuum to prevent oxidation by designing the vacuum forming structure inside / outside the tube.

[0023] Furthermore, according to the present invention, the number of wafers that need to be processed by configuring the heater in two or more stages can be increased as needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is a diagram showing an operation flow of an ultrahigh temperature heat treatment apparatus according to an embodiment of the present invention.

[0025] Figure 2 FIG. 1 is a diagram showing a structure of a heater according to an embodiment of the present invention.

[0026] Figure 3 FIG. 1 is a diagram showing a cross section of an ultrahigh temperature heat treatment apparatus according to an embodiment of the present invention.

[0027] Figure 4 It is a diagram showing the upper part of a heater according to an embodiment of the present invention.

[0028] Figure 5 FIG. 1 is a diagram showing a lower cavity according to an embodiment of the present invention.

[0029] Figure 6 A cylindrical tungsten heater and a guide formed of a mesh according to an embodiment of the present invention are shown. DETAILED DESCRIPTION

[0030] Taking a specific embodiment capable of implementing the present invention as an example, the present invention described below is described in detail with reference to the illustrated drawings. These embodiments are described in detail so that those skilled in the art can fully implement the present invention. It should be understood that, although the various embodiments of the present invention are different from each other, they do not need to be mutually exclusive. For example, the specific shapes, structures and characteristics described herein are related to an embodiment and can be implemented by other embodiments without departing from the spirit and scope of the present invention. In addition, it should be understood that the position or arrangement of the individual constituent elements in each disclosed embodiment can be changed without departing from the spirit and scope of the present invention. Therefore, the detailed description described below is not taken for the purpose of limitation. If the scope of the present invention can be properly described, it is limited to all scopes equal to the scope of the claim and the claims attached thereto. Similar reference numerals in the figures refer to having the same or similar functions on multiple sides.

[0031] Hereinafter, in order to enable those skilled in the art to easily implement the present invention, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0032] Figure 1 1 is a diagram showing an operation flow of an ultrahigh temperature heat treatment apparatus according to an embodiment of the present invention.

[0033] The heat treatment of SiC wafers requires ultra-high temperature conditions of 1500 to 1900 degrees. In the semiconductor oxidation process, the heat treatment can basically be carried out through the processes of wafer loading S100, ramp up S110, stabilization S120, oxidation S130A and ramp down S140. At this time, the temperature of the above steps S110 to S130A can reach up to 1500 degrees.

[0034] Furthermore, in the semiconductor activation process, heat treatment can be performed through the processes of wafer loading S100, ramp up S110, stabilization S120, activation S130B, and ramp down S140. At this time, the temperature of the above steps S110 to S130B can reach up to 1900 degrees.

[0035] The ultrahigh temperature heat treatment apparatus 100 of the present disclosure includes a heater 110 made of a heat-resistant tungsten material. The heater 110 is connected to an electrode 130 close to a power supply unit.

[0036] In addition, cooling water flows through the cooling line 120 around the ultrahigh temperature heat treatment device 100 to prevent overheating, thereby protecting the ultrahigh temperature heat treatment device 100. Specifically, the cooling line 120 through which the cooling water flows can be located outside the reflector 180 of the ultrahigh temperature heat treatment device 100.

[0037] In addition, cooling water flows around each electrode 130 independently of the cooling line 120, thereby preventing the electrode from overheating. As described later, the present invention may have three electrodes 130. If each of the three electrodes 130 overheats, it may cause damage to the device. Therefore, in order to prevent these problems, it can be configured so that the cooling water flows to the outside of the electrode 130.

[0038] On the one hand, in each step of oxidation S130A and activation S130B, a process gas (such as oxygen or nitrogen) is introduced according to preset conditions for heat treatment, and a vacuum process may be included. Compared with the existing horizontal furnace device for Si wafer heat treatment, the core function of the ultra-high temperature heat treatment device 100 that can perform SiC wafer heat treatment may correspond to achieving uniformity of ultra-high temperature heating and oxidation heat treatment.

[0039] The heater 110 of the ultrahigh temperature heat treatment device 100 of the present invention can utilize a heater 110 made of graphite or metal tungsten material that can generate heat above 2000 degrees, and the tube 140 and boat that are heat-resistant to high temperatures above 2000 degrees can be made of graphite material.

[0040] At this time, the tube 140 is a long cylindrical container or pipe used in the semiconductor heat treatment process, which can generally be used to separate the internal and external environments. At this time, the tube 140 plays an important role in maintaining and managing a specific temperature, gas or environment in the semiconductor process.

[0041] On the contrary, the boat refers to a small-volume special container or boat-shaped protective device mainly used in the semiconductor thermal treatment process. Generally speaking, the boat has a shape that can safely load semiconductor wafers and can transfer the wafers to the semiconductor thermal treatment and protect them.

[0042] The ultra-high temperature heat treatment device 100 of the present invention may include a cylindrical heater 110 of a mesh type tungsten material in a diagonal direction. The above-mentioned mesh type cylindrical heater 110 as a mesh structure is composed of a mesh type heat wire of a tungsten material, which is used to convert the electrical energy received from the electrode into thermal energy, and heat is uniformly heated along the mesh type heat wire (S110). That is, according to step S100, it is possible to avoid reducing the yield due to uneven heat treatment of the wafers loaded on the boat based on the position, thereby having the effect of improving efficiency.

[0043] In addition, when the heater 110 reaches a preset high temperature of ex400 degrees, the vacuum pump works to make the inside and outside of the tube 140 in a vacuum state. This can be used to remove impurities in the air during semiconductor heat treatment, provide a high temperature environment for semiconductor devices, and prevent oxidation and internal contamination of the heater, etc.

[0044] Figure 2 FIG. 1 is a diagram showing a structure of a heater according to an embodiment of the present invention.

[0045] like Figure 2 As shown, the heater 110 of the present invention is equivalent to a cylindrical shape, is a metal tungsten material, can withstand a heating temperature of more than 2000 degrees, and is composed of a grid (net) type (see Figure 6 ).

[0046] The above-mentioned grid-type cylindrical heater 110 can be divided into a plurality of uniform arcs for division. At this time, each of the above-mentioned divided arcs can be referred to as a part of the heater 110. That is, each part is rectangular in shape when unfolded, but when a plurality of parts are gathered, a cylindrical heater 110 can be formed.

[0047] A guide 150 is installed on one side of each of the above-mentioned multiple parts, and each of the multiple guides 150 is connected to the corresponding electrode 130, so that heat can be transferred to each part. For reference, as mentioned above, cooling water flows around each electrode 130, so that overheating of the electrode 130 can be prevented.

[0048] It can be assumed that the heater 110 can be roughly divided into three arc-shaped parts (120 degrees apart), including a first part, a second part and a third part. Figure 2 As shown, there may be a preset space (gap) between the above three parts.

[0049] At this time, the thermocouple may be located between the first part and the second part, and a pyrometer may be located between the second part and the third part (of course, the positions of the thermocouple and the pyrometer may be changed according to the setting). The thermocouple 170 and the pyrometer 160 may both measure the internal temperature of the heater 110. The temperature measurement of the thermocouple 170 and the pyrometer 160 will be described in detail later.

[0050] On the one hand, considering economy and output, the number of wafers processed at one time by the ultra-high temperature processing device 100 of the present invention is preferably about 60. However, if more wafers need to be processed, the height can be increased by adding segments of the heater 110.

[0051] For example, when the number of wafers increases (about 60 or more), the heater 110 currently composed of one stage is composed of two or more stages, so that more than 120 wafers can be heat-treated at one time. When the heater 110 is composed of two or more stages, the electrodes 130 and the guides 150 are increased in structure.

[0052] Figure 3 FIG. 1 is a diagram showing a cross section of an ultrahigh temperature heat treatment apparatus 100 according to an embodiment of the present invention.

[0053] The ultra-high temperature heat treatment device 100 of the present invention may include a thermocouple 170 that changes its operation mode based on temperature. The thermocouple 170 is highly accurate and stable when measuring heat, but may be damaged by heat at ultra-high temperatures above a certain temperature. Therefore, when the temperature of the heater 110 of the ultra-high temperature heat treatment device 100 of the present invention reaches a preset temperature ex1600 degrees that may damage the thermocouple 170, the above-mentioned thermocouple 170 can automatically exit (withdraw).

[0054] That is, the thermocouple 170 enters (in) to measure the internal temperature when the internal temperature is below the preset temperature ex1600 degrees, and exits (out) from the inside of the tube 140 and is located outside the heater 110 when the preset temperature ex1600 degrees is above, and no internal temperature above the preset temperature ex1600 degrees can be measured. This is to protect the thermocouple 170.

[0055] For example, the action of withdrawing the thermocouple 170 may include: moving the thermocouple 170 to be withdrawn along the normal direction of the heater 110, so that the thermocouple 170 exists outside the heater 110 to protect the thermocouple from ultra-high temperature. At this time, the thermocouple 170 may move forward and backward according to the operation. For reference, the in / out movement of the thermocouple 170 may be horizontally moved by various driving methods such as a linear motor.

[0056] On the contrary, the pyrometer 160 can continue to measure the internal temperature of the ultra-high temperature heat treatment device 100 regardless of the preset temperature, based on which, even when the thermocouple 170 is withdrawn, the pyrometer 160 can continue to measure the internal temperature of the ultra-high temperature heat treatment device 100. Finally, the temperature measurement at the ultra-high temperature above the preset temperature ex1600 degrees can be performed using the pyrometer 160 after the thermocouple 170 is withdrawn.

[0057] Specifically, if Figure 3 As shown, the ultra-high temperature heat treatment device 100 has a thermocouple 170 and a pyrometer 160 for measuring the internal temperature. When the internal temperature gradually rises to an ultra-high temperature above a certain temperature, the thermocouple 170 can be automatically withdrawn.

[0058] On the contrary, the pyrometer 160 may continue to measure the internal temperature of the ultrahigh temperature heat treatment apparatus 100 regardless of a certain temperature, and accordingly, the pyrometer 160 may continue to measure the internal temperature of the ultrahigh temperature heat treatment apparatus 100 even when the thermocouple 170 is withdrawn.

[0059] For reference, in Figure 3 There is no Figure 2 The electrode 130 is shown as shown, but Figure 2 and Figure 3 It is the same part, but from a different perspective, so it should be understood as Figure 3 Electrode 130 is also present.

[0060] Figure 4 FIG. 1 is a diagram showing an upper portion 110 of a heater according to an embodiment of the present invention.

[0061] In addition, the reflector 180 of the upper cavity 200 of the ultra-high temperature heat treatment device 100 can be composed of 10 layers (or 11 layers) of heat insulation material, in which case the 1st to 6th layers are composed of tungsten materials, and the 7th and above layers are composed of molybdenum materials, which can effectively insulate from the outside. In addition, the material exposed to the outside can include stainless steel materials, including SUS310S. Figure 4 , the upper portion of the heater 110 according to an embodiment of the present invention may include three electrodes 130 and a guide portion 150. That is, the upper portion of the heater 110 may be divided into three parts, each of which may be in an arc shape of 120 degrees.

[0062] In the ultra-high temperature heat treatment device 100, the tube 140 may be located between the reflector and the heater 110, and the tube 140 may be a graphite material that is heat-resistant to ultra-high temperatures. In addition, a vacuum pump may be included inside and outside the tube 140 made of the graphite material, and the vacuum pump maintains the inside and outside of the tube 140 in a vacuum state, thereby blocking variables that may be generated by the inflow of gas (the graphite material as the material of the tube 140 allows air to pass through, so it is necessary to maintain the inside and outside of the tube 140 in a vacuum state).

[0063] Figure 5 FIG. 1 is a diagram showing a lower cavity 300 according to an embodiment of the present invention.

[0064] The reflector 180 at the bottom of the ultra-high temperature heat treatment device 100 can be composed of 6 layers of heat insulation materials, 1 to 3 layers are composed of tungsten materials, and 4 to 6 layers are composed of molybdenum materials, which can effectively insulate from the outside.

[0065] In addition, the ultra-high temperature heat treatment device 100 of the present invention includes a cooling line 120 around its periphery, and the upper end of the device can be maintained at about 70 degrees, and the middle and lower ends can be maintained at 30 to 40 degrees.

[0066] The ultra-high temperature heat treatment device 100 may include a graphite tube 140 having heat resistance to ultra-high temperature, and vacuum pumps may be included inside and outside the tube 140. This is because particles such as oxygen can pass through the graphite tube 140, and the inside and outside of the graphite tube 140 must be kept in a vacuum state.

[0067] When the ultra-high temperature heat treatment device 100 or the heater 110 reaches a preset temperature of ex400 degrees, the vacuum pump can be controlled to work. A vacuum can be formed inside / outside the tube 140 by the vacuum pump to prevent oxidation and internal contamination of the heater 110, etc.

[0068] Figure 6 A cylindrical tungsten heater 110 and a guide portion 150 formed of a mesh according to an embodiment of the present invention are shown.

[0069] The heater 110 according to an embodiment of the present invention may be a cylindrical heater 110 formed of a mesh of tungsten material. The heater 110 is not directly connected to the ultrahigh temperature heat treatment device 100, but may be fixed in the ultrahigh temperature heat treatment device 100 through the installation guide 150.

[0070] Reference Figure 6 The heater 110 of the present invention can be evenly divided into three arc-shaped parts, and the upper and lower ends of each part are equipped with guide parts 150, so that the connected parts can be fixed. In particular, the guide parts 150-1 installed at the upper end of each part can be connected to the corresponding electrodes 130 by welding.

[0071] The guide portion 150 corresponds to a temperature changing portion, and thus heat transfer from the electrode 130 to the heater 110 can be smoothly performed.

[0072] Although the present invention has been described above through specific matters such as specific constituent elements and limited embodiments and drawings, this is only provided to help facilitate a more comprehensive understanding of the present invention. The present invention is not limited to the above-mentioned embodiments. Anyone with common knowledge in the technical field to which the present invention belongs can attempt to make various modifications and variations from these records.

[0073] Therefore, the concept of the present invention is not limited to the above-described embodiments, and not only the scope of the claims described below, but all modifications that are equal or equivalent to the scope of the claims belong to the scope of the concept of the present invention.

Claims

1. An ultra-high temperature heat treatment device, characterized in that: include: Tungsten cylindrical heater; as well as Tubes, made of materials resistant to extremely high temperatures, The heater is composed of a grid structure.

2. The ultra-high temperature heat treatment device according to claim 1, characterized in that: The heater of the grid structure is divided into a plurality of parts, and a guide part is installed on one side of each of the plurality of parts, and the plurality of guide parts are respectively connected to corresponding electrodes.

3. The ultra-high temperature heat treatment device according to claim 2, characterized in that: The heater is divided into three arc-shaped parts, including a first part, a second part, and a third part. A thermocouple located between the first part and the second part and a pyrometer located between the second part and the third part measure the internal temperature of the heater.

4. The ultra-high temperature heat treatment device according to claim 3, characterized in that: When the internal temperature of the heater reaches a preset temperature, the thermocouple located inside the heater moves and is located outside the heater.

5. The ultra-high temperature heat treatment device according to claim 1, characterized in that: The tube is made of graphite material.

6. The ultra-high temperature heat treatment device according to claim 1, characterized in that: include: A vacuum pump sucks air from inside and outside the tube. When the heater reaches a preset temperature, the vacuum pump is operated to place the inside and outside of the tube in a vacuum state.

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