Silicon carbide thermal field thermal insulation structure
By using a three-layer insulation cylinder and a pore-guided channel design, the stress concentration and ablation problems caused by the difference in thermal expansion coefficients in the silicon carbide thermal field are solved, extending the service life of the thermal field and improving the stability and quality of single crystal growth.
Patent Information
- Application Number
- CN202520166497.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2035-01-23
AI Technical Summary
In existing silicon carbide thermal fields, the difference in thermal expansion coefficients between the insulation cylinder and the crucible leads to stress concentration at high temperatures, affecting service life and stability, and causing severe ablation.
The insulation cylinder adopts a three-layer structure, consisting of an inner insulation layer, a middle insulation layer, and an outer insulation layer from the inside out. The coefficient of thermal expansion changes gradually, and the design of pores and guide channels reduces stress and ablation.
It extends the lifespan of the thermal field, improves the stability and quality of single crystal growth, and reduces the ablation of gases such as Si, Si2C, and SiC2.
Smart Images
Figure CN223738212U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a semiconductor technical field especially is related to a silicon carbide heat field heat preservation structure. BACKGROUND
[0002] The related art points out that the silicon carbide crystal growth heat field is usually provided with a heat preservation cylinder outside the crucible to ensure that the temperature distribution in the crucible is relatively constant, but the thermal expansion system, density and other physical characteristics of the crucible and the heat preservation cylinder have great differences, the heat preservation cylinder and the crucible used in the silicon carbide heat field are both graphite materials, the thermal expansion system of the graphite material increases with the increase of temperature, and the temperature of the silicon carbide single crystal growth is 2100-2300 DEG C, under high temperature, the heat preservation material at the position of the interface line of the heat preservation cylinder and the crucible bears a large stress, and is ablated by Si, Si2C, SiC2 and other gases, which seriously affects the service life. Therefore, how to slow down the stress and ablation speed of the heat preservation material under high temperature at the position to improve the service life and stability of the heat field is a technical problem to be solved at present. SUMMARY
[0003] The utility model aims at at least one of the prior art existing technical problems. For this purpose, the utility model provides a silicon carbide heat field heat preservation structure, which can prolong the service life of the heat field and improve the stability of single crystal growth.
[0004] To achieve the above-mentioned purpose of the application, the utility model provides a silicon carbide heat field heat preservation structure, which comprises a heat preservation cylinder and a crucible, the crucible is located in the heat preservation cylinder, and the outer wall of the crucible is tightly attached to the inner wall of the heat preservation cylinder, the upper part of the crucible is provided with a crucible cover, and the upper part of the crucible cover is uniformly provided with air holes; the upper part of the heat preservation cylinder is sealed by an upper heat preservation layer, the lower part of the heat preservation cylinder is sealed by a lower heat preservation layer, the heat preservation cylinder is uniformly provided with a flow guide groove along the upper edge, and the flow guide groove corresponds to the position of the air hole.
[0005] In some embodiments, the heat preservation cylinder of the utility model is composed of an inner heat preservation layer, a middle heat preservation layer and an outer heat preservation layer from inside to outside, the thermal expansion system of the inner heat preservation layer is 1.5-3.0*10 -6 / K, the density is 0.5-1.0g / cm 3 , the expansion coefficient of the middle heat preservation layer is less than 1.0*10 -6 / K, the density is 0.05-0.2g / cm 3 , the thermal expansion coefficient of the crucible is 2.7-4.5*10 -6 / K, and the density is 1.50-1.80g / cm 3 , the outer heat preservation layer is made of the same material as the inner heat preservation layer, and the thickness of the middle heat preservation layer is the thickest.
[0006] In some embodiments, the diversion groove is internally provided with a graphite diversion plate.
[0007] In some embodiments, the air hole and the diversion groove are both provided with four, and one-to-one correspondence.
[0008] In some embodiments, the upper heat preservation layer, the lower heat preservation layer and the heat preservation cylinder are all made of heat preservation felt.
[0009] Compared with the prior art, the utility model has the following advantages:
[0010] 1) the utility model discloses a heat preservation cylinder of three-layer structure and a crucible close to the inner heat preservation layer material, effectively reduces the stress generated between different materials due to thermal expansion under high temperature environment, thereby prolonging the service life of the thermal field, and improving the stability and quality of the thermal field and single crystal growth.
[0011] 2) the utility model discloses that the air hole is formed on the graphite cover, and the diversion groove is formed on the upper edge of the heat preservation cylinder, and the graphite diversion plate is placed in the diversion groove, which effectively reduces the ablation of Si, Si2C, SiC2 and other gases to the thermal field, and further prolongs the service life of the thermal field.
[0012] 3) the utility model discloses simple structure, practical and strong, and can be widely applied to single crystal growth.
[0013] The additional aspects and advantages of the utility model will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 is the schematic diagram of the silicon carbide thermal field heat preservation structure according to one embodiment of the utility model;
[0015] Figure 2 is the heat preservation cylinder overhead view of the silicon carbide thermal field heat preservation structure according to one embodiment of the utility model;
[0016] Figure 3 is the graphite cover overhead view of the silicon carbide thermal field heat preservation structure according to one embodiment of the utility model;
[0017] Figure 4 is the diversion groove and graphite diversion plate position schematic diagram of the silicon carbide thermal field heat preservation structure according to one embodiment of the utility model;
[0018] Reference signs:
[0019] 1000: silicon carbide thermal field heat preservation structure;
[0020] 200: upper heat preservation layer;
[0021] 300: flow guide groove; 301: graphite flow guide plate;
[0022] 400: heat preservation cylinder; 401: inner heat preservation layer; 402: middle heat preservation layer; 403: outer heat preservation layer;
[0023] 500: lower heat preservation layer;
[0024] 600: crucible cover;
[0025] 700: crucible. DETAILED DESCRIPTION
[0026] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein like reference numerals refer to like elements or elements with similar functions throughout the figures. The embodiments described below are exemplary and intended to provide an explanation of the application, and are not intended to restrict the application. The following detailed description is provided with reference to the accompanying figures.
[0027] The disclosure below provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplicity, the elements and settings of the particular examples below are described in some instances by reference to the drawings. Of course, that description of the elements and settings should not be construed to limit the scope of the application. Rather, the description is provided as a representative sample of the many different ways the components and settings of the application can be implemented. Additionally, the application can be implemented in different examples with variations that do not depart from the spirit or scope of the present application. Such variations are intended to be within the scope of the present application. Further, the disclosure of particular examples using specific terminology should not be construed to limit the scope of the present application. Rather, the specific examples are provided in order to provide a thorough understanding of the present application.
[0028] The following detailed description is provided with reference to the accompanying drawings. Figures 1-4The utility model discloses a silicon carbide thermal field heat preservation structure 1000, including heat preservation cylinder 400 and crucible 700, crucible 700 is placed in heat preservation cylinder 400, and the outer wall of crucible 700 is close to the inner wall of heat preservation cylinder 400, and the crucible 700 is used to load the raw material required for silicon carbide single crystal growth, the upper portion of crucible 700 is installed crucible cover 600, and the upper portion of crucible cover 600 is uniformly distributed with air hole, and the setting of air hole is favorable to the volatilization of Si, Si2C, SiC2 etc. Figure 2 and Figure 3 .
[0029] In some embodiments, the utility model heat preservation cylinder 400 is three layer structure, by inside and outside in proper order by inner heat preservation layer 401, middle heat preservation layer 402 and outer heat preservation layer 403 are constituted, and the thermal expansion system of inner heat preservation layer 401 is 1.5~3.0x10 -6 / K, and the density is 0.5~1.0g / cm 3 , preferably, the thermal expansion system of inner heat preservation layer 401 in the utility model embodiment is 2.0x10 -6 / K, and the density is 0.8g / cm 3 , and the thermal expansion coefficient of crucible 700 is 2.7~4.5x10 -6 / K, and the density is 1.50~1.80g / cm 3 , preferably, the thermal expansion coefficient of inner crucible 700 in the utility model embodiment is 3.0x10 -6 / K, and the density is 1.65g / cm 3 , and the thermal expansion coefficient and the density of inner heat preservation layer 401 and crucible 700 are not much different, reduce the stress that the heat preservation cylinder 400 produces because of the uneven thermal expansion, improve the stability and durability of whole thermal field system, and the expansion coefficient of middle heat preservation layer 402 is less than 1.0x10 -6 / K, and the density is 0.05~0.2g / cm 3 , preferably, the expansion coefficient of middle heat preservation layer 402 in the utility model embodiment is 0.8x10 -6 / K, and the density is 0.09g / cm 3The thickness of the middle heat preservation layer 402 is greater than the thickness of the inner heat preservation layer 401 and the outer heat preservation layer 403, in other words, the thickness of the middle heat preservation layer 402 is the greatest among the three heat preservation layers, so that the overall heat preservation effect is improved; the outer heat preservation layer 403 is made of the same material as the inner heat preservation layer 401, so that the stability of the overall structure of the thermal field is effectively maintained.
[0030] With reference to Figure 4 As shown in the figure, in some embodiments, the graphite flow guide plate 301 is placed in the flow guide groove 300. The graphite flow guide plate 301 in the embodiment effectively prevents the crystallization of the gas phase components in the flow guide groove 300, keeps the flow guide groove 300 unobstructed, and thus ensures the flow of Si, Si2C, SiC2 and other gases to the outside of the thermal field.
[0031] The heat preservation cylinder 400 of the utility model adopts a multi-layer structure, and the material is matched with the material of the crucible 700, so that the stress generated between different materials due to thermal expansion under a high-temperature environment is significantly reduced, thereby prolonging the service life of the thermal field. The utility model discloses that the gas hole is arranged on the crucible cover 600, the flow guide groove 300 is arranged on the heat preservation cylinder 400, and the graphite flow guide plate 301 is placed in the flow guide groove 300, so that the ablation of Si, Si2C, SiC2 and other gases to the thermal field is effectively reduced, and the service life of the thermal field is further prolonged.
[0032] Other components of the silicon carbide thermal field heat preservation structure 1000 according to the utility model embodiment, such as the crucible 700, the upper heat preservation layer 200 and the lower heat preservation layer 500, and the operation are known to those skilled in the art, and will not be described in detail here.
[0033] In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.
[0034] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and do not connote or imply any relative importance or any meaning pertaining to the quantity of the features being described. Thus, a feature defined with "first", "second", etc. can include one or more of the features implicitly or explicitly. In the description of the present application, the meaning of "a plurality" is two or more, unless specifically defined otherwise.
[0035] In the present application, unless specifically defined and limited otherwise, the terms "mounting", "connecting", "connection", "fixed", and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection, and can also be communication; can be directly connected, can also be indirectly connected through an intermediate medium, and can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0036] In the present application, unless specifically defined and limited otherwise, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.
[0037] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or features of different embodiments or examples described in the present application without contradiction.
[0038] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.
Claims
1. A silicon carbide hot face heat retaining structure, characterized by, The application relates to a heat preservation cylinder and a crucible, the crucible is located in the heat preservation cylinder, the outer wall of the crucible is close to the inner wall of the heat preservation cylinder, a crucible cover is installed on the upper part of the crucible, and air holes are uniformly distributed on the upper periphery of the crucible cover; the upper part of the heat preservation cylinder is sealed through an upper heat preservation layer, the lower part of the heat preservation cylinder is sealed through a lower heat preservation layer, and flow guide grooves are uniformly distributed on the upper part of the heat preservation cylinder and correspond to the positions of the air holes.
2. A silicon carbide hot face heat retaining structure according to claim 1, wherein The heat preservation cylinder is composed of inner heat preservation layer, middle heat preservation layer and outer heat preservation layer from inside to outside, the thermal expansion system of the inner heat preservation layer is 1.5-3.0*10 -6 / K, the density is 0.5-1.0g / cm 3 , the expansion coefficient of the middle heat preservation layer is less than 1.0*10 -6 / K, the density is 0.05-0.2g / cm 3 , the thermal expansion coefficient of the crucible is 2.7-4.5*10 -6 / K, the density is 1.50-1.80g / cm 3 , the outer heat preservation layer is made of the same material as the inner heat preservation layer, and the thickness of the middle heat preservation layer is the thickest.
3. The silicon carbide hot face heat retaining structure according to claim 1, wherein Graphite flow guide plates are arranged in the flow guide grooves.
4. The silicon carbide hot face heat retaining structure according to claim 1, wherein The air holes and the flow guide grooves are provided with four air holes and four flow guide grooves respectively and correspond to each other.
5. A silicon carbide hot face heat retaining structure according to any one of claims 2 to 4, wherein The upper heat preservation layer, the lower heat preservation layer and the heat preservation cylinder are all made of heat preservation felt.