CN220433072U - Crystal growth apparatus - Google Patents

Abstract

The utility model discloses a crystal growth device, comprising: a crucible; the material placing component comprises a base, a cylindrical side plate and a separation filter screen, the base is positioned in the crucible and arranged at the bottom of the crucible, the base is attached to the bottom of the crucible, the cylindrical side plate is positioned in the crucible and attached to the side wall of the crucible, and the cylindrical side plate surrounds the base, so that a raw material cavity for placing raw materials is formed between the cylindrical side plate and the base; the separation filter screens are multiple in number, extend along the axis direction of the crucible respectively, and are sequentially arranged in the raw material cavity; the plurality of separating screens separate the feedstock chamber into a plurality of feedstock placement areas and at least one first atmosphere passage. The crystal growth device provided by the embodiment of the utility model can reduce the risk of carbon encapsulation in the crystal growth process, is beneficial to the maximum sublimation of raw materials and improves the utilization rate of the raw materials.

Description

Crystal growth apparatus

Technical Field

The present utility model relates generally to the field of crystal growth technology. More particularly, the present utility model relates to a crystal growth apparatus.

Background

Silicon carbide is used as a third-generation wide band gap semiconductor material which is most mature in development at present, has the advantages of high heat conductivity, high breakdown field strength, high saturated electron drift rate and the like, so that the silicon carbide can meet the new requirements of modern electronic technology on high temperature, high frequency, high power and radiation resistance, and the silicon carbide device is also widely used in the fields of aerospace detection, nuclear energy development, satellites, radars, communication and the like. Compared with traditional semiconductor materials such as silicon, gallium arsenide and the like, silicon carbide has wider development prospect.

In view of the wide application prospect of silicon carbide devices, the growth mode of silicon carbide single crystals becomes one of the international research hot spots. Currently, the growth modes of silicon carbide single crystals include a physical vapor transport method (pvd), a high temperature chemical vapor deposition method, a liquid phase epitaxy method, etc., wherein the physical vapor transport method (PVT) is the mainstream growth mode of silicon carbide single crystals at present, and is adopted by most research institutions and companies. When the PVT method is adopted to grow the silicon carbide monocrystal, the silicon carbide raw material is placed at the bottom of a crucible and heated to more than 2000 ℃, and the silicon carbide raw material sublimates to a cold seed crystal at the top of the crucible to deposit crystals under a low-pressure environment.

However, when a silicon carbide single crystal is grown by the PVT method, the silicon carbide raw material contacting with the high temperature region such as the side wall of the crucible and the surface layer of the bottom of the crucible is seriously carbonized, and carbon particles are easily formed, which increases the risk of carbon inclusion during the crystal growth.

Disclosure of Invention

In order to solve the technical problems, the utility model provides a crystal growth device, which can reduce the risk of carbon encapsulation in the crystal growth process.

The present utility model provides a crystal growth apparatus comprising: a crucible; the material placing assembly comprises a base, a cylindrical side plate and a separation filter screen, wherein the base is positioned in the crucible and arranged at the bottom of the crucible, the base is attached to the bottom of the crucible, the cylindrical side plate is positioned in the crucible and attached to the side wall of the crucible, the cylindrical side plate comprises a first end close to the bottom of the crucible and a second end far away from the bottom of the crucible, the cylindrical side plate is arranged around the base, and the first end of the cylindrical side plate is connected with the base so that a raw material cavity for placing raw materials is formed between the cylindrical side plate and the base; the number of the separation filter screens is multiple, the separation filter screens extend along the axial direction of the crucible respectively and are sequentially arranged in the raw material cavity, and a space is reserved between any two adjacent separation filter screens; the separation filter screens divide the raw material cavity into a plurality of raw material placement areas and at least one first atmosphere channel, and the raw material placement areas and the first atmosphere channels are alternately arranged.

Compared with the prior art, the crystal growth device provided by the utility model has the advantages that the material placing component comprising the base, the cylindrical side plate and the separation filter screen is arranged in the crucible, so that raw materials for crystal growth can be separated from the bottom and the side wall of the crucible, the carbonization problem caused by direct contact of the raw materials with the side wall of the crucible and the bottom of the crucible is effectively avoided, the risk of carbon wrapping in the crystal growth process is reduced, the raw materials are placed in a partitioned manner through the plurality of separation filter screens so as to be heated uniformly, and the first atmosphere channel is arranged between the adjacent raw material placing areas so as to facilitate the atmosphere rising of each raw material placing area, thereby being beneficial to the maximum sublimation of the raw materials and improving the utilization rate of the raw materials.

Drawings

The above, as well as additional purposes, features, and advantages of exemplary embodiments of the present utility model will become readily apparent from the following detailed description when read in conjunction with the accompanying drawings. In the drawings, embodiments of the utility model are illustrated by way of example and not by way of limitation, and like reference numerals refer to similar or corresponding parts and in which:

FIG. 1 is a schematic view showing the structure of a crystal growth apparatus according to an embodiment of the present utility model;

FIG. 2 shows a schematic top cross-sectional view of a crystal growing apparatus including a plurality of cylindrically configured separation screens according to an embodiment of the present utility model;

FIG. 3 is a schematic view showing the structure of a crystal growing apparatus including a second atmosphere passage according to an embodiment of the present utility model; and

fig. 4 shows a top cross-sectional view of the crystal growing apparatus shown in fig. 3.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be understood that the terms "comprises" and "comprising," when used in this specification and in the claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the utility model herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used in the specification and claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the term "and/or" as used in the present specification and claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

In the description of the present utility model, it should be noted that, if the terms "upper", "lower", "inner", "outer", etc. indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, or the azimuth or the positional relationship in which the inventive product is conventionally put in use, it is merely for convenience of describing the present utility model and simplifying the description, and it is not indicated or implied that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated.

Specific embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

Fig. 1 shows a schematic structural view of a crystal growth apparatus according to an embodiment of the present utility model. As shown in fig. 1, the present utility model provides a crystal growth apparatus, which may include a crucible 100 and a loading assembly, wherein the loading assembly may include a base 210, a cylindrical side plate 220, and a separation screen, the base 210 is positioned within the crucible 100 and positioned at the bottom of the crucible 100, the base 210 is attached to the bottom of the crucible 100, the cylindrical side plate 220 is positioned within the crucible 100 and attached to a sidewall of the crucible 100, the cylindrical side plate 220 may include a first end 221 near the bottom of the crucible 100 and a second end 222 remote from the bottom of the crucible 100, the cylindrical side plate 220 is disposed around the base 210, and the first end 221 of the cylindrical side plate 220 is connected to the base 210 such that a raw material cavity 230 for placing raw materials is formed between the cylindrical side plate 220 and the base 210.

In some embodiments, the material of the material placing component may be high density graphite or the like. In other embodiments, the surface of the placement component may be provided with a carbide coating, which may be a tantalum carbide layer or a titanium carbide layer, or the like. According to the arrangement, the service life of the material placing component can be prolonged, and new carbon sources brought after the material placing component is corroded can be avoided. In one embodiment, the carbide coating may be provided on the outer surface of the loading assembly to avoid carbonization of the interface of the loading assembly and the crucible 100.

In some embodiments, the shape of the base 210 may be adapted to the cross-sectional shape of the barrel side plate 220 to facilitate connection with the first end 221 of the barrel side plate 220. For example, in some application scenarios, the cross-sectional shape of the cylindrical side plate 220 may be a circle, a square, a polygon, or the like, and the shape of the base 210 may be correspondingly configured as a circle, a square, a polygon, or the like. In other applications, since the cylindrical side plate 220 is attached to the side wall of the crucible 100 and the base 210 is attached to the bottom of the crucible 100, the cross-sectional shape of the cylindrical side plate 220 may be the same as the cross-sectional shape of the inner wall of the crucible 100, and the shape of the base 210 may be the same as the shape of the bottom of the crucible 100.

The height of the cylindrical side plate 220 may be less than the height of the crucible 100 such that the second end 222 of the cylindrical side plate 220 is positioned within the crucible 100. The first end 221 of the cylindrical side plate 220 is connected to the base 210, and may be fixedly connected or detachably connected. The formation of the source chamber 230 for placing the source material between the cylindrical side plate 220 and the base 210 means that the source chamber 230 is formed between the upper side of the base 210 and the inner side of the cylindrical side plate 220, and the source material may be silicon carbide source material for forming a silicon carbide single crystal or source material required for other types of crystal growth.

It will be appreciated that by providing the pedestal 210, the feedstock on the pedestal 210 may be spaced from the bottom of the crucible 100 to avoid severe carbonization of the feedstock by direct contact with the bottom of the crucible 100. By providing the cylindrical side plate 220, the raw material inside the cylindrical side plate 220 can be separated from the side wall of the crucible 100 to avoid serious carbonization caused by direct contact of the raw material with the side wall of the crucible 100.

As further shown in fig. 1, the number of the separation screens according to the embodiment of the present utility model may be plural (e.g., the first separation screen 240-1 and the second separation screen 240-2 in the drawings), and the plural separation screens may extend in the axial direction of the crucible 100 and may be sequentially disposed in the raw material chamber 230 with a space between any adjacent two separation screens; the plurality of separating screens separate the raw material chamber 230 into a plurality of raw material placement regions (e.g., a first raw material placement region 250-1 and a second raw material placement region 250-2 in the illustration) and at least one first atmosphere channel 310, the raw material placement regions and the first atmosphere channels 310 being alternately arranged.

The axial direction of the crucible 100 as used herein refers to the direction of the central axis of the crucible 100 (for example, the direction indicated by an arrow in the drawing), or the direction parallel to the central axis. In some embodiments, the separating screen may be provided in a plate-like structure or a cylindrical structure. In other embodiments, the separation screen may be a graphite screen. In still other embodiments, the separation screen may be a graphite screen with a porosity of 10-100 μm. In some embodiments, the height of the separating screen may be less than or equal to the height of the cylindrical side panels 220.

It can be understood that the raw material cavity is divided into a plurality of raw material placement areas through the separation filter screen, and raw materials can be separated, so that the raw materials can not be stacked too thick, the raw materials can be heated more uniformly, and the sublimation degree and the utilization rate of the raw materials are improved. Further, the separating screen may be attached to the material in the material placement area. The separation filter screen not only can be used for separating a plurality of raw material placement areas, but also can filter carbon particles possibly carried in raw material atmosphere formed when raw materials are heated and sublimated, so that the risk of carbon wrapping in the crystal formation process at the seed crystal is reduced.

In other embodiments, the base 210 may be provided with a first groove, where the first groove may be adapted to the first end of the separating filter, and the first end of the separating filter may be engaged in the first groove. The first end of the separation screen may be the end of the separation screen near the base 210 (or near the bottom of the crucible). The first groove being adapted to the first end of the separating filter screen may mean that the shape of the first groove is adapted to the shape of the first end of the separating filter screen, for example, when the separating filter screen is of a plate-like structure or a sheet-like structure, the first groove may be a bar-like groove; when the separating filter screen is of a cylindrical structure, the first groove may be an annular groove. In still other embodiments, the number of first grooves may be the same as the number of separating screens, and the clamping may be performed in a one-to-one correspondence.

In order to facilitate the explanation of the case where the first atmosphere passage 310 is formed between the plurality of partition screens, the case where the plurality of partition screens are in a plate-like structure will be explained. As shown in fig. 1, a plurality of separation screens are each extended in the axial direction of the crucible 100 and are arranged in the raw material chamber at intervals in order. For example, the first and second separating screens 240-1 and 240-2 are spaced apart to form the first raw material placement area 250-1, the first atmosphere passage 310, and the second raw material placement area 250-2.

The alternate arrangement of the material placement areas and the first atmosphere channels 310 may be such as the first material placement areas 250-1→the first atmosphere channels 310→the second material placement areas 250-2 shown in the drawings, that is, the areas adjacent to the material placement areas are the first atmosphere channels 310 and the areas adjacent to the first atmosphere channels 310 are the material placement areas. For the case where the number of the partition screens is more than two, the alternate arrangement of the raw material placement area and the first atmosphere passage 310 may be: the first raw material placement area 250-1→the first atmosphere passage 310→the second raw material placement area 250-2→the first atmosphere passage 310, and so on.

The first atmosphere passage 310 described above may open into the top (or open end) of the crucible 100 so that the gas formed by sublimation of the feedstock can rise (e.g., in the direction indicated by the arrow in the drawing) along the first atmosphere passage 310 to the cold seed at the top of the crucible 100 for deposition crystallization. For example, the illustrated crucible 100 may include a crucible body and a crucible cover 320, the crucible cover may cover an open end of the crucible body, and a seed stage 321 may be disposed inside the crucible cover 320, and the seed stage 321 may be used to place a seed crystal. The gas formed by sublimation of the feedstock may rise along the first atmosphere channel 310 to a seed on the seed table 321 for crystallization. In some application scenarios, the crucible 100 may be a graphite crucible with a thickness of 5-30mm, the crucible cover may be a graphite cover with a thickness of 5-30mm, the graphite cover may be attached to the crucible body, and the center of the crucible cover may be attached with seed crystals.

In some embodiments, any adjacent two separate screens may be parallel to each other. For example, the first and second separating screens 240-1 and 240-2 are shown to be parallel to each other. In still other embodiments, the separating screen may be a cylindrical structure or a plate-like structure; in the case where the partition screens are of a plate-like structure, one of any adjacent two partition screens (e.g., the first partition screen 240-1 in the drawing and the second partition screen 240-2 in the drawing) is located on one side of the other partition screen (e.g., the second partition screen 240-2 in the drawing) and the two are disposed opposite to each other; under the condition that the separation filter screens are of cylindrical structures, one of any two adjacent separation filter screens is sleeved on the outer side of the other separation filter screen. In order to facilitate understanding of the case where the plurality of partition screens are cylindrical in structure, an exemplary description will be made below with reference to a top sectional view of a crystal growing apparatus including the plurality of partition screens of cylindrical structure shown in fig. 2.

Fig. 2 shows a schematic top cross-sectional view of a crystal growing apparatus including a plurality of cylindrically configured separation screens according to an embodiment of the present utility model. As shown in fig. 2, the crystal growing apparatus may include a crucible 100 and a loading assembly, which may include a base and a cylindrical side plate 220, and further include a plurality of separation screens (e.g., a first separation screen 240-1 and a second separation screen 240-2 in the drawings), and in this embodiment, the plurality of separation screens may each be a cylindrical structure, two adjacent separation screens (e.g., the first separation screen 240-1 and the second separation screen 240-2 in the drawings) may have a space therebetween, and one of the separation screens (e.g., the first separation screen 240-1 in the drawings) may be sleeved outside the other separation screen (e.g., the second separation screen 240-2 in the drawings). The plurality of separating screens separate the feedstock chambers into a plurality of feedstock placement areas (e.g., first feedstock placement area 250-1 and second feedstock placement area 250-2 in the illustration) and at least one first atmosphere channel 310, the plurality of feedstock placement areas and first atmosphere channels 310 may be alternately disposed from inside to outside or from outside to inside as illustrated, e.g., in an alternating manner of first feedstock placement area 250-1→first atmosphere channel 310→second feedstock placement area 250-2 as illustrated.

While the crystal growth apparatus including the plurality of partition screens according to the embodiment of the present utility model has been exemplarily described above with reference to fig. 1 and 2, it will be appreciated that by providing the plurality of partition screens to divide the raw material chamber into the plurality of raw material placement areas and the at least one first atmosphere passage, not only can the raw material be partitioned to be heated uniformly, but also an atmosphere rising passage can be provided to facilitate atmosphere rising, thereby facilitating maximum sublimation of the raw material and improving the utilization rate of the raw material.

It will also be appreciated that the above description is exemplary and not limiting, e.g., the number of separating screens may not be limited to two in the illustration, but may be more as desired. Taking the case of the cylindrical structure as an example of the separating screen shown in fig. 2, in case that the number of separating screens is three, assuming that a third separating screen is sleeved on the inner side of the second separating screen 240-2 shown in fig. 2, according to the principle that the material placement areas are alternately arranged with the first atmosphere channels, the inner side of the third separating screen may form the first atmosphere channels, and the material placement areas may be between the third separating screen and the second separating screen 240-2, so that an alternating manner of the first atmosphere channels 310, the second material placement areas 250-2, the first atmosphere channels 310, the first material placement areas 250-1 may be formed. Therefore, in light of the technical teaching of the embodiments of the present utility model, those skilled in the art may set the number of separating screens and the interval area between adjacent separating screens as the raw material placement area or the first atmosphere passage according to the actual application needs.

Fig. 3 shows a schematic structural view of a crystal growth apparatus including a second atmosphere passage according to an embodiment of the present utility model. Fig. 4 shows a top cross-sectional view of the crystal growing apparatus shown in fig. 3. As shown in fig. 3 and 4, the crystal growing apparatus may include a crucible 100 and a loading assembly, which may include a base 210 and a cylindrical side plate 220, and a plurality of separation screens 240, and in this embodiment, the plurality of separation screens 240 may each have a cylindrical structure.

In some embodiments, a through hole 510 penetrating through the base 210 is provided in the middle of the base 210, and the central axis of the through hole 510 is parallel to the axis of the crucible 100; the placement component may further comprise: a second atmosphere passage 520, the second atmosphere passage 520 extending along the axial direction of the crucible 100, and the second atmosphere passage 520 communicating with the through hole 510; and a first filter screen 530, wherein the first filter screen 530 extends along the axial direction of the crucible 100 and is arranged around the second atmosphere channel 520, the first filter screen 530 is connected with the base 210, the cylindrical side plate 220 is sleeved outside the first filter screen 530 and is arranged at intervals with the first filter screen 530, and a raw material cavity is formed among the cylindrical side plate 220, the base 210 and the first filter screen 530. The plurality of separation screens 240 divide the feedstock chamber into a plurality of feedstock placement areas 250 and at least one first atmosphere channel 310 that are alternately arranged. After the raw materials in the raw material cavity are heated, the sublimated silicon carbide atmosphere rises along the first atmosphere channel 310 and the second atmosphere channel 520 (in the direction indicated by the arrow in the figure) to the seed crystal position on the seed crystal table 321 of the crucible cover 320 to deposit crystals.

The shape of the through holes 510 may be, for example, circular, square, or other regular or irregular shapes. The cross-sectional shape of the second atmosphere passage 520, which is surrounded by the first screen, may be the same as the shape of the through-hole 510. One end of the first strainer 530 near the bottom of the crucible 100 is connected to the base 220, and may be fixedly connected or detachably connected. The first screen 530 is disposed around the second atmosphere passage 520, meaning that the second atmosphere passage 520 is surrounded on the inner side of the first screen 530 such that the second atmosphere passage 520 is separated from the raw material chamber on the outer side of the first screen 530. The first screen 530 may be a graphite screen. In other embodiments, the first screen 530 may be a graphite screen with a porosity of 10-100 μm. The outer side of the first filter screen 530 may be attached to the raw material in the raw material placement area and serves to filter out carbon particles in the raw material atmosphere formed after sublimation of the raw material, so as to prevent the carbon particles from rising to the seed crystal in the second atmosphere passage 520.

Through set up second atmosphere passageway 520 on the middle part of base 210, both can provide more atmosphere passageway in order to help the even heating and the sublimation of raw materials, can also effectively avoid the raw materials to pile up at the middle part of crucible and lead to the raw materials of this place to sublimate slowly or take place the problem of sublimation to be favorable to further improving the utilization ratio of raw materials, and reduction in production cost.

In other embodiments, the width of any one of the first atmosphere channels is smaller than the width of any one of the raw material placement regions in the radial direction of the crucible, and the width of the second atmosphere channel 520 is larger than the width of any one of the first atmosphere channels. Wherein the radial direction of the crucible is a direction perpendicular to the axial direction of the crucible. The width of the first atmosphere channel is controlled to be smaller than that of the raw material placement area, so that a larger raw material placement space can be obtained while an atmosphere rising channel is provided so as to facilitate atmosphere rising; the width of the second atmosphere channel is controlled to be larger than that of the first atmosphere channel, so that the uniform heating and sublimation of the raw materials are facilitated, and the problem that the raw materials sublimate slowly or are not sublimated can be effectively avoided.

As further shown in fig. 3, in some embodiments, the placement assembly may further include a second screen 540, which second screen 540 may cover the top of the raw material cavity, each separate screen being located between the base 210 and the second screen 540, one end of each separate screen being connected to the base 210, and the other end of each separate screen being connected to the second screen 540. The second screen 540 may be a graphite screen. In other embodiments, the second screen 540 may be a graphite screen with a porosity of 10-100 μm. The second filter screen 540 is covered on the top of the raw material cavity, and can block carbon particles rising along with the raw material atmosphere in the raw material cavity, so that the defect that the carbon particles are blown up by the raw material atmosphere and carried to the crystal growth surface to form a wrapper is avoided; each separating filter screen is located between the base 210 and the second filter screen 540, and one end of each separating filter screen is connected with the base 210, and the other end of each separating filter screen is connected with the second filter screen 540, so that each raw material placing area and each first atmosphere channel are independent in space and are not easy to interfere with each other.

In other embodiments, the second filter 540 may have an annular structure, the second filter 540 is sleeved outside the first filter 530, the second filter 540 is located between the first filter 530 and the cylindrical side plate 220, the second filter 540 abuts against the first filter 530, and the second filter 540 abuts against the cylindrical side plate 220. The central hole of the second screen 540 of the ring structure may communicate with the second atmosphere passage 520. The second filter 540 may be in contact with the first filter 530, and the inner side of the second filter 540 may be in contact with the outer side of the first filter 530, and the two may be in fixed contact or detachable contact. The second filter 540 may be in contact with the cylindrical side plate 220, and the outer side of the second filter 540 may be in contact with the inner side of the cylindrical side plate 220, and the two may be in fixed contact or detachable contact. Abutment is understood to mean abutment and connection.

In still other embodiments, the number of second screens 540 may be provided in plurality. For example, the number of the second screens 540 may be equal to the number of the raw material placement areas, and may be disposed at the top of the raw material placement areas in a one-to-one correspondence. Taking the crystal growing apparatus shown in fig. 3 as an example, it includes two material placement areas 250, two second filter screens 540 having annular structures may be disposed, wherein the second filter screen 540 having one annular structure is sleeved outside the second filter screen 540 having the other annular structure, and is disposed at the top of the two material placement areas 250, respectively.

It should be understood that, although the case that the plurality of separating screens are in a cylindrical structure is described above in connection with fig. 3 and 4, the arrangement is similar when the plurality of separating screens are in a plate-like structure, for example, the plurality of separating screens with plate-like structure may be separately disposed at both sides of the first screen 530 to form a plurality of raw material placement areas and at least one first atmosphere passage, which will not be described herein.

As will be appreciated from the description of the crystal growth apparatus according to the embodiments of the present utility model above in conjunction with the various figures, by providing a loading assembly comprising a base, a cylindrical side plate, and a plurality of separating screens, the present utility model isolates the feedstock from high temperature regions such as the side walls and bottom of the crucible, thereby facilitating a reduction in the carbonization degree of the feedstock, and a reduction in the carbon particles in the atmosphere of the feedstock, thereby avoiding the risk of carbon inclusion formation from the feedstock end. Through setting up a plurality of separation filter screens, can form a plurality of raw materials and place district and at least one first atmosphere passageway for the raw materials can not pile up too thick, thereby the heating of raw materials can be more even, and the atmosphere that forms rises the passageway and also is favorable to promoting the maximum sublimation of raw materials, and then effectively improves raw materials utilization ratio.

While various embodiments of the present utility model have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous modifications, changes, and substitutions will occur to those skilled in the art without departing from the spirit and scope of the utility model. It should be understood that various alternatives to the embodiments of the utility model described herein may be employed in practicing the utility model. The appended claims are intended to define the scope of the utility model and are therefore to cover all equivalents or alternatives falling within the scope of these claims.

Claims (10)

1. A crystal growth apparatus, comprising:

a crucible; and

the material placing assembly comprises a base, a cylindrical side plate and a separation filter screen, wherein the base is positioned in the crucible and arranged at the bottom of the crucible, the base is attached to the bottom of the crucible, the cylindrical side plate is positioned in the crucible and attached to the side wall of the crucible, the cylindrical side plate comprises a first end close to the bottom of the crucible and a second end far away from the bottom of the crucible, the cylindrical side plate is arranged around the base, and the first end of the cylindrical side plate is connected with the base so that a raw material cavity for placing raw materials is formed between the cylindrical side plate and the base;

the number of the separation filter screens is multiple, the separation filter screens extend along the axial direction of the crucible respectively and are sequentially arranged in the raw material cavity, and a space is reserved between any two adjacent separation filter screens; the separation filter screens divide the raw material cavity into a plurality of raw material placement areas and at least one first atmosphere channel, and the raw material placement areas and the first atmosphere channels are alternately arranged.

2. The crystal growing apparatus of claim 1 wherein the separating screen is a cylindrical structure; under the condition that the separation filter screens are of cylindrical structures, one of any two adjacent separation filter screens is sleeved on the outer side of the other separation filter screen;

or the separation filter screen is of a plate-shaped structure; under the condition that the separation filter screens are of plate-shaped structures, one of any two adjacent separation filter screens is positioned on one side of the other separation filter screen, and the two separation filter screens are arranged oppositely.

3. The crystal growing apparatus of claim 1 wherein any adjacent two of the separating screens are parallel to each other.

4. The crystal growth apparatus of claim 1, wherein the base is provided with a first recess, the first recess being adapted to a first end of the separation screen, the first end of the separation screen being snapped into the first recess.

5. The crystal growth apparatus according to any one of claims 1 to 4, wherein a through hole penetrating the base is provided in a middle portion of the base, and a central axis of the through hole is parallel to an axis of the crucible;

the material placing component further comprises:

a second atmosphere passage extending in an axial direction of the crucible and communicating with the through hole; and

the first filter screen, first filter screen is followed the axis direction of crucible extends and encircles the setting of second atmosphere passageway, first filter screen with the base is connected, the tube-shape curb plate cover is located the first filter screen outside and with first filter screen interval sets up, the tube-shape curb plate the base and form between the first filter screen the raw materials chamber.

6. The crystal growth apparatus according to claim 5, wherein a width of any one of the first atmosphere channels is smaller than a width of any one of the raw material placement regions in a radial direction of the crucible, and a width of the second atmosphere channel is larger than a width of any one of the first atmosphere channels.

7. The crystal growing apparatus of claim 5, wherein the placement assembly further comprises a second screen, the second screen covering the top of the feedstock cavity;

each separation filter screen is located between the base and the second filter screen, one end of each separation filter screen is connected with the base, and the other end of each separation filter screen is connected with the second filter screen.

8. The crystal growth apparatus of claim 7, wherein the second screen is of an annular structure, the second screen is sleeved outside the first screen, the second screen is located between the first screen and the cylindrical side plate, the second screen abuts against the first screen, and the second screen abuts against the cylindrical side plate.

9. The crystal growth apparatus of claim 1, wherein the surface of the placement component is provided with a carbide coating, and the carbide coating is a tantalum carbide layer or a titanium carbide layer.

10. The crystal growth apparatus of claim 1, wherein the separation screen is a graphite screen having a porosity of 10-100 μm.