Crucible for crystal growth
By setting up barrier nets and graphite paper in the crucible, the problem of bubble diffusion affecting crystal quality is solved, and high-quality crystal growth is achieved.
Patent Information
- Application Number
- CN202422013541.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-08-19
AI Technical Summary
In the lifting and growth method, the bubbles generated by heating the melt in the crucible expand to the seed crystal, resulting in the formation of pores in the crystal and affecting the crystal quality.
A barrier net is provided on the inner side wall and bottom wall of the crucible, and graphite paper is provided on the top. Exhaust holes are provided on the graphite paper to prevent the diffusion of bubbles and control the emission of volatiles. It is designed with appropriate mesh, thickness and distance to ensure crystal growth quality.
Effectively avoiding bubbles diffusion to the seed crystals, improving the quality and purity of crystal growth, and simplifying the crystal generation process.
Smart Images
Figure CN223176258U_ABST
Abstract
Description
Technical Field
[0001] This specification relates to the field of crystal growth, and particularly to a crucible for crystal growth. Background Art
[0002] As a semiconductor material, silicon carbide has very excellent physical and chemical properties and has broad application prospects and market space in high-end optoelectronics, high-power, and microwave radio frequency fields.
[0003] Common crystal growth methods include the Czochralski method. The Czochralski method means that a seed crystal is slowly immersed in the melt in a crucible. After the end face of the seed crystal contacts the melt and slightly melts, the seed crystal is slowly pulled up while rotating. This process prompts the atoms in the melt to arrange regularly according to the crystal structure of the seed crystal and solidify and grow to form a crystal. However, bubbles are generated when the melt in the crucible is heated, resulting in the expansion of the bubbles to the seed crystal during the Czochralski growth process, and there may be pores in the generated crystal, affecting the quality of the crystal.
[0004] Therefore, it is desirable to propose a crucible for crystal growth to prevent bubbles from expanding to the seed crystal and improve the quality of crystal growth. Summary of the Invention
[0005] One or more embodiments of this specification provide a crucible for crystal growth. The crucible is arranged in a crystal growth device and is used to hold a melt. The crucible includes a barrier net, and the barrier net is arranged on the inner side wall and the inner bottom wall of the crucible.
[0006] In some embodiments, a graphite paper is arranged at the top of the barrier net. The graphite paper is located above the melt, and exhaust holes are formed at the outer edge of the graphite paper.
[0007] In some embodiments, the purity of the graphite paper is greater than 99%.
[0008] In some embodiments, the maximum distance between the exhaust holes and the inner side wall of the crucible in the radial direction of the crucible is a first distance, and the minimum distance between the outer side wall of the seed crystal holder used in cooperation with the crucible and the inner side wall of the crucible in the radial direction of the crucible is a second distance. Among them, the first distance is less than the second distance.
[0009] In some embodiments, the thickness range of the graphite paper is 0.25 - 2.5 mm.
[0010] In some embodiments, the mesh number range of the exhaust holes on the graphite paper is 0.5 - 5 mm.
[0011] In some embodiments, the barrier net is made of one or more of quartz, iridium gold, platinum-rhodium alloy, and tantalum.
[0012] In some embodiments, the mesh number of the barrier net ranges from 20 to 40.
[0013] In some embodiments, the thickness of the barrier net ranges from 0.5 to 1.8 mm.
[0014] In some embodiments, the minimum distance between the outer sidewall of the seed crystal holder used in conjunction with the crucible and the inner sidewall of the crucible in the radial direction of the crucible is a second distance, and the maximum distance between the barrier net provided inside the inner sidewall of the crucible and the inner sidewall of the crucible in the radial direction of the crucible is a third distance, wherein the second distance is greater than the third distance. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] This specification will be further described by way of exemplary embodiments, which will be described in detail through the drawings. These embodiments are not restrictive. In these embodiments, the same reference numerals represent the same structures, where:
[0016] Figure 1 is a schematic structural view of a crucible for crystal growth according to some embodiments of this specification;
[0017] Figure 2 is another schematic structural view of a crucible for crystal growth according to some embodiments of this specification. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] To more clearly illustrate the technical solutions of the embodiments of this specification, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some examples or embodiments of this specification. For those of ordinary skill in the art, without creative efforts, this specification can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the figures represent the same structures or operations.
[0019] It should be understood that the "system", "device", "unit" and / or "module" used herein is a way to distinguish different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the said words can be replaced by other expressions.
[0020] As shown in this specification and the claims, unless the context clearly indicates an exceptional situation, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.
[0021] Flowcharts are used in this specification to illustrate the operations performed by the systems according to the embodiments of this specification. It should be understood that the preceding or subsequent operations are not necessarily performed precisely in sequence. On the contrary, the steps can be processed in reverse order or simultaneously. Also, other operations can be added to these processes, or one or several steps can be removed from these processes.
[0022] Figure 1 is a schematic structural diagram of a crucible for crystal growth shown according to some embodiments of this specification.
[0023] As Figure 1 shown, the crucible 100 is disposed in the crystal growth apparatus, and the aforementioned crucible 100 is used to hold the melt. The aforementioned melt can be formed by melting the production raw materials required for crystal growth and the flux at high temperature.
[0024] It can be understood that when heating the melt in the crucible 100 based on the crystal growth apparatus (for example, the induction heating coil in the crystal growth apparatus), the melt boiling may generate bubbles. When the bubbles diffuse to the vicinity of the seed crystal holder 200, it may affect the seed crystal on the seed crystal holder 200, thereby reducing the quality of crystal growth. Based on this, a barrier net 110 for blocking the diffusion of bubbles can be provided inside the crucible 100 in this specification. The barrier net 110 can be disposed along the inner walls of the crucible 100, as Figure 1 shown. In some embodiments, the barrier net 110 is provided on both the inner side wall 101 and the inner bottom wall 102 of the crucible 100.
[0025] In some embodiments, the barrier net 110 can be made of a material that is resistant to high-temperature melt corrosion and has good chemical stability to avoid changes in the properties of the barrier net 110 when heating the melt. For example, the barrier net 110 can be made of one or more of quartz, iridium gold, platinum-rhodium alloy, tantalum, etc.
[0026] In some embodiments, the mesh number of the barrier net 110 can be determined by presetting. For example, the mesh number of the barrier net 110 can be preset to 20 - 80. Different mesh number ranges of the barrier net 110 can be used in different crystal growth processes. For example, 20 - 40, 40 - 60, 60 - 80, etc. In some embodiments, the mesh number range of the barrier net 110 is 20 - 40. Preferably, the mesh number range of the barrier net 110 can be 25 - 35. For example, the mesh number of the barrier net 110 can be 30 mesh. By limiting the mesh number of the barrier net 110 as described above, it is possible to avoid the mesh number of the barrier net 110 being too small, which affects the fluidity of the melt. At the same time, it can also avoid the mesh number of the barrier net 110 being too large, which cannot block the bubbles and reduces the quality of crystal growth. In some embodiments, the thickness range of the barrier net 110 is 0.5 - 1.8 mm.
[0027] During different crystal growth processes, the thickness of the barrier net 110 can be different. For example, the thickness range of the barrier net 110 can include 0.5 - 0.8 mm, 0.8 - 1.2 mm, and 1.2 - 1.8 mm. Preferably, the thickness range of the barrier net 110 can be 0.8 - 1.2 mm. For example, the thickness of the barrier net 110 can be 1 mm. In some embodiments of this specification, by restricting the thickness of the barrier net 110, it is possible to avoid the thickness of the barrier net 110 being too thick and affecting the smoothness of the melt flow, and it is also possible to avoid the thickness of the barrier net 110 being too thin and being prone to deformation.
[0028] In some embodiments, as Figure 1 shown, the minimum distance between the outer sidewall of the seed crystal holder 200 used in conjunction with the crucible 100 and the inner sidewall 101 of the crucible 100 in the radial direction of the crucible is the second distance D2, and the maximum distance between the barrier net 110 provided inside the inner sidewall 101 of the crucible 100 and the inner sidewall 101 of the crucible 100 in the radial direction of the crucible 100 is the third distance D3. The second distance D2 is greater than the third distance D3 to ensure that the seed crystal holder 200 can move axially within the crucible 100 and avoid the seed crystal holder 200 colliding with the barrier net 110 during movement, which may affect the crystal growth process.
[0029] In some embodiments of this specification, by providing the barrier net 110 in the crucible 100, it is possible to avoid the bubbles generated during the boiling of the melt from diffusing to the vicinity of the seed crystal holder 200 and affecting the seed crystals on the seed crystal holder 200, thus ensuring the quality of crystal growth.
[0030] In some embodiments, as Figure 1 shown, before starting crystal growth, a graphite paper 120 is provided on the top of the barrier net 110. The aforementioned graphite paper 120 is located above the melt, and exhaust holes 121 are provided at the outer edge of the graphite paper 120. It should be noted that during the process of heating the crucible 100 to melt the raw materials, the seed crystal is directly above the material surface. At high temperatures, part of the melt will volatilize and is likely to deposit on the seed crystal growth surface of the seed crystal holder 200 facing the melt, forming two-dimensional nucleation, which is not conducive to subsequent single crystal growth. In some embodiments of this specification, by providing the graphite paper 120 with exhaust holes 121, it is possible to avoid the influence of volatiles on the seed crystal growth surface in the seed crystal holder 200 during the heating and raw material homogenization stages, thus ensuring the quality of crystal formation.
[0031] In some embodiments, the diameter of the graphite paper 120 can be smaller than the inner diameter of the crucible 100 and larger than the inner diameter of the barrier net 110 to ensure that it can be provided on the top of the barrier net 110 inside the crucible 100.
[0032] In some embodiments, the mesh number range of the exhaust holes 121 on the graphite paper 120 is 0.5 - 5 mm. In some embodiments, the mesh number range of the exhaust holes 121 on the graphite paper 120 is 0.8 - 3 mm. In some embodiments, the mesh number range of the exhaust holes 121 on the graphite paper 120 is 1 - 2 mm. During different crystal growth processes, graphite papers 120 with different mesh number ranges can be used. By restricting the mesh number range of the exhaust holes 121 on the graphite paper 120, it is possible to avoid the exhaust holes 121 being too small to timely discharge the volatilized melt, and also avoid the exhaust holes 121 being too large to restrict the exhaust direction of the volatilized melt, and the discharged volatilized melt still diffuses towards the seed crystal growth surface of the seed crystal holder 200, affecting the quality of crystal formation.
[0033] In some embodiments, as Figure 1 shown, the maximum distance between the exhaust hole 121 and the inner side wall 101 of the crucible 100 in the radial direction of the crucible 100 is the first distance D1, and the first distance D1 is less than the second distance D2, so as to ensure that the volatilized melt discharged from the exhaust hole 121 will not rise to the seed crystal growth surface of the seed crystal holder 200, affecting the quality of crystal formation.
[0034] In some embodiments, the difference between the first distance D1 and the second distance D2 is not less than 10 mm, so as to prevent the volatilized melt discharged from the exhaust hole 121 from diffusing to the seed crystal growth surface of the seed crystal holder 200, affecting the quality of crystal formation.
[0035] In some embodiments, when starting crystal growth, the graphite paper 120 can be taken out of the crucible 100 so that the seed crystal on the seed crystal holder 200 can contact the melt and form crystals.
[0036] Figure 2 is another schematic structural view of a crucible for crystal growth according to some embodiments of this specification.
[0037] In some embodiments, as Figure 2 shown, when starting crystal growth, the seed crystal holder 200 can tilt and press the graphite paper 120 into the melt, and the graphite paper 120 can melt in the melt. By this setting, it is possible to avoid taking out the graphite paper 120 again, simplifying the crystal growth process.
[0038] In some embodiments, the purity of the graphite paper 120 can be greater than 99%. In some embodiments, the purity of the graphite paper 120 can be greater than 99.5%. In some embodiments, the purity of the graphite paper 120 can be greater than 99.8%. By restricting the purity of the graphite paper 120, the purity of the materials in the melt can be ensured, and the quality of crystal formation can be ensured.
[0039] In some embodiments, the thickness of the graphite paper 120 ranges from 0.25 mm to 2.5 mm. In some embodiments, the thickness of the graphite paper 120 ranges from 0.5 to 2 mm. In some embodiments, the thickness of the graphite paper 120 ranges from 1 to 1.5 mm. By limiting the thickness of the graphite paper 120, it is possible to avoid the situation where the graphite paper 120 is too thick, which may damage the seeds on the seed holder 200 or make it difficult to press the graphite paper 120 into the melt during the process of the seed holder 200 pressing the graphite paper 120 into the melt. It can also avoid the situation where the graphite paper 120 is too thin, which may cause the upward airflow generated by the volatilization of the melt to blow up the graphite paper 120 or cause the graphite paper 120 to deform, thus unable to limit the discharge of the volatile melt.
[0040] In some embodiments of this specification, by arranging the graphite paper 120 in the crucible 100, the exhaust direction of the volatile melt can be controlled, avoiding its influence on the seed growth surface in the seed holder 200 and ensuring the quality of crystal formation.
[0041] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are proposed in this specification, so such modifications, improvements, and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.
[0042] At the same time, this specification uses specific terms to describe the embodiments of this specification. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.
[0043] In addition, unless clearly stated in the claims, the order of the processing elements and sequences, the use of numbers, letters, or other names in this specification is not used to limit the order of the processes and methods in this specification. Although various examples are discussed in the above disclosure for some currently considered useful invention embodiments, it should be understood that such details only serve the purpose of illustration. The appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that conform to the essence and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only through software solutions, such as installing the described system on existing servers or mobile devices.
[0044] Similarly, it should be noted that, in order to simplify the presentation disclosed in this specification and thus assist in the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of this specification, multiple features are sometimes grouped into one embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the features required by the subject matter of this specification are more than those recited in the claims. In fact, the features of the embodiments are fewer than all the features of the individual embodiments disclosed above.
[0045] In some embodiments, numbers are used to describe components and the quantity of attributes. It should be understood that such numbers used to describe the embodiments are, in some examples, modified by the modifiers "about", "approximate", or "substantially". Unless otherwise stated, "about", "approximate", or "substantially" indicate that the said numbers are allowed to have a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, and such approximate values may vary according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used in some embodiments of this specification to confirm the breadth of their scope are approximate values, in specific embodiments, such numerical settings are as precise as possible within the feasible range.
[0046] For each patent, patent application, patent application publication, and other materials cited in this specification, such as articles, books, specifications, publications, documents, etc., their entire contents are hereby incorporated into this specification by reference. Except for the application history documents that are inconsistent with or conflict with the content of this specification, and also except for the documents that limit the broadest scope of the claims of this specification (currently or subsequently appended to this specification). It should be noted that if there are inconsistencies or conflicts between the descriptions, definitions, and / or uses of terms in the supplementary materials of this specification and the content described in this specification, the descriptions, definitions, and / or uses of terms in this specification shall prevail.
[0047] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered to be consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.
Claims
1. A crucible for crystal growth, characterized in that, The crucible is disposed in a crystal growth apparatus, and the crucible is used to hold a melt. The crucible includes a barrier net, and the barrier net is disposed on the inner sidewall and the inner bottom wall of the crucible.
2. The crucible according to claim 1, characterized in that, Graphite paper is disposed on the top of the barrier net. The graphite paper is located above the melt, and exhaust holes are formed on the outer edge of the graphite paper.
3. The crucible according to claim 2, wherein, The purity of the graphite paper is greater than 99%.
4. The crucible according to claim 2, characterized in that, The maximum distance in the radial direction of the crucible between the exhaust holes and the inner sidewall of the crucible is a first distance, and the minimum distance in the radial direction of the crucible between the outer sidewall of a seed crystal holder used in cooperation with the crucible and the inner sidewall of the crucible is a second distance. Wherein, The first distance is less than the second distance.
5. The crucible according to claim 2, wherein The thickness range of the graphite paper is 0.25 to 2.5 mm.
6. The crucible according to claim 2, wherein, The mesh number range of the exhaust holes on the graphite paper is 0.5 to 5 mm.
7. The crucible according to claim 1, characterized in that, The mesh number range of the barrier net is 20 to 40.
8. The crucible according to claim 1, wherein The thickness range of the barrier net is 0.5 to 1.8 mm.
9. The crucible according to claim 1, characterized in that, The minimum distance in the radial direction of the crucible between the outer sidewall of a seed crystal holder used in cooperation with the crucible and the inner sidewall of the crucible is a second distance, and the maximum distance in the radial direction of the crucible between the barrier net disposed on the inner side of the inner sidewall of the crucible and the inner sidewall of the crucible is a third distance. Wherein, The second distance is greater than the third distance.