CN114941174A

CN114941174A - Silicon carbide crystal growth device and filling method

Info

Publication number: CN114941174A
Application number: CN202210643789.7A
Authority: CN
Inventors: 袁文博; 张洁; 洪棋典
Original assignee: Fujian Norstel Material Technologies Co ltd
Current assignee: Fujian Norstel Material Technologies Co ltd
Priority date: 2022-06-08
Filing date: 2022-06-08
Publication date: 2022-08-26

Abstract

The invention discloses a silicon carbide crystal growth device and a filling method, and relates to the technical field of silicon carbide crystal preparation; the device comprises a crucible body, a crucible cover, a plurality of first flow guide pieces and a plurality of second flow guide pieces; the crucible body comprises a crucible bottom wall and a crucible side wall, and a cavity is formed by enclosing the crucible bottom wall and the crucible side wall; the crucible cover is arranged on one side of the crucible side wall opposite to the crucible bottom wall; the first flow guide piece extends from the side wall of the crucible to the middle part of the chamber; the second flow guide piece extends from the middle part of the chamber to the side wall of the crucible; the first flow guide and the second flow guide are located on different planes, and an atmosphere transmission channel is configured between the first flow guide and the second flow guide. The device can prolong the ascending stroke of the gas-phase component of the silicon carbide through the matching of the first flow guide part and the second flow guide part, prevent the carbon particles from moving towards the seed crystal and ensure the growth quality of the silicon carbide crystal.

Description

Silicon carbide crystal growth device and filling method

Technical Field

The invention relates to the technical field of silicon carbide crystal preparation, in particular to a silicon carbide crystal growth device and a filling method.

Background

Silicon carbide (SiC) is a representative material of third-generation wide band gap semiconductor materials, has a large forbidden band width, a high critical breakdown electric field strength, a high carrier saturation migration speed, a high thermal conductivity, and excellent chemical stability based on the excellent physicochemical properties, and has wide applications in the fields of microelectronics and optoelectronics.

At present, the growth of silicon carbide single crystal takes Physical Vapor Transport (PVT) as a main growth mode, and has proved to be the most mature method for growing SiC crystal. The main process comprises the steps of heating SiC powder to 2200-2500 ℃ for sublimation, and crystallizing the sublimated atmosphere on cold-end seed crystals to form silicon carbide crystals under the protection of inert atmosphere.

However, in the prior art, the growth process of the silicon carbide crystal is very long, which often requires more than 100 hours, and the long time easily causes the imbalance of the ratio of Si to C in the gas phase generated by the silicon carbide powder, so that the carbonization phenomenon is easily generated. Carbon particles generated by raw material carbonization are brought to the surface of the crystal along with airflow, so that carbon packages are easily formed, the formation of the carbon packages directly causes the reduction of the crystal quality, and MPD (silicon carbide wafer micro-tube density) defects, polytype and other quality defects are induced in serious cases, so that the whole crystal is scrapped, and the loss is caused to the actual production.

Disclosure of Invention

The invention aims to provide a silicon carbide crystal growing device, which can prolong the ascending stroke of a silicon carbide gas-phase component, prevent carbon particles from moving towards seed crystals and ensure the growth quality of the silicon carbide crystal through the matching arrangement of a first flow guide part and a second flow guide part.

Another object of the present invention is to provide a method for loading a silicon carbide crystal growth apparatus, which can further improve the growth quality of silicon carbide crystals by loading a second material with a slower volatilization rate between the first material and the side wall of the crucible, thereby limiting the carbonization of the materials on the energy head and reducing the occurrence probability of carbon coating.

The embodiment of the invention is realized by the following steps:

in a first aspect, the present invention provides an apparatus for growing a silicon carbide crystal, comprising:

the crucible body comprises a crucible bottom wall and a crucible side wall, and the crucible bottom wall and the crucible side wall are enclosed to form a cavity;

the crucible cover is arranged on one side of the crucible side wall opposite to the crucible bottom wall;

the first flow guide pieces extend from the side wall of the crucible to the middle part of the chamber;

the second flow guide pieces extend from the middle part of the cavity to the side wall of the crucible;

the first flow guide and the second flow guide are located on different planes, and an atmosphere transmission channel is configured between the first flow guide and the second flow guide.

In an alternative embodiment, at least one second flow guide member is arranged between two adjacent first flow guide members along the direction from the bottom wall of the crucible to the crucible cover, or at least one first flow guide member is arranged between two adjacent second flow guide members.

In an optional embodiment, the first flow guide part is obliquely arranged towards the direction of the crucible cover, one end, far away from the side wall of the crucible, of the first flow guide part is encircled to form an atmosphere transmission port communicated with the atmosphere transmission channel, and an orthographic projection surface of the second flow guide part on the plane in the radial direction covers or covers and exceeds the atmosphere transmission port.

In an alternative embodiment, the growing apparatus further comprises:

one end of the supporting piece is connected with the middle part of the second flow guide piece, and the other end of the supporting piece is connected with the bottom wall of the crucible and penetrates through the atmosphere transmission channel.

In an alternative embodiment, the support member is arranged perpendicular to the bottom wall of the crucible, and the second flow guide member is arranged perpendicular to the support member; or the supporting piece is perpendicular to the bottom wall of the crucible, and one end, far away from the supporting piece, of the second flow guide piece is obliquely arranged towards the direction of the bottom wall of the crucible.

In an alternative embodiment, a support body for supporting the first baffle member is provided on the side wall of the crucible.

In an alternative embodiment, the inner edge of the crucible side wall at the end remote from the crucible bottom wall is inclined relative to the axial direction and tapers in the direction of the crucible cover and encloses the flow guide chamber.

In an alternative embodiment, the chamber comprises a growth chamber and a feedstock chamber in communication with each other; the growth chamber is close to one side of the crucible cover, and the raw material chamber is close to one side of the crucible bottom wall;

the first flow guide piece and the second flow guide piece are arranged in the growth chamber;

the raw material chamber comprises a first containing area and a second containing area which are used for filling different raw materials, wherein the second containing area is wound outside the first containing area.

In an alternative embodiment, the orthographic projection surface of the first flow guide piece on the plane of the radial direction covers or covers and exceeds the orthographic projection surface of the second accommodating area on the plane of the radial direction.

In a second aspect, the present invention provides a method of loading a silicon carbide crystal growing apparatus, the silicon carbide crystal growing apparatus comprising: the crucible comprises a crucible body, a crucible cover, a plurality of first flow guide pieces and a plurality of second flow guide pieces; the crucible body comprises a crucible bottom wall and a crucible side wall, a cavity is formed by enclosing the crucible bottom wall and the crucible side wall, a crucible cover is arranged on one side of the crucible side wall opposite to the crucible bottom wall in a covering mode, the cavity comprises a growth cavity and a raw material cavity which are communicated with each other, the growth cavity is close to one side of the crucible cover, the raw material cavity is close to one side of the crucible bottom wall, the raw material cavity comprises a first accommodating area and a second accommodating area, and the second accommodating area is wound outside the first accommodating area; the first flow guide piece extends from the side wall of the crucible to the middle part of the chamber; the second flow guide piece extends from the middle part of the chamber to the side wall of the crucible; the first flow guide part and the second flow guide part are positioned on different planes, and an atmosphere transmission channel is arranged between the first flow guide part and the second flow guide part;

a method of filling comprising:

filling a first raw material in the first containing area;

filling a second raw material in the second accommodating area; the first raw material and the second raw material are different raw materials, and the volatilization rate of the first raw material is greater than that of the second raw material.

In an alternative embodiment, the first feedstock and the second feedstock are the same feedstock in different forms;

wherein the first raw material is silicon carbide powder, and the second raw material is silicon carbide lump material.

In an alternative embodiment, before filling the first holding section with the first material, the filling method further comprises:

the first containing area is filled with cerium compound powder.

The embodiment of the invention has at least the following advantages or beneficial effects:

the embodiment of the invention provides a silicon carbide crystal growth device, which comprises a crucible body, a crucible cover, a plurality of first flow guide pieces and a plurality of second flow guide pieces, wherein the crucible body is provided with a plurality of first flow guide pieces; the crucible body comprises a crucible bottom wall and a crucible side wall, and a cavity is formed by enclosing the crucible bottom wall and the crucible side wall; the crucible cover is arranged on one side of the crucible side wall opposite to the crucible bottom wall; the first flow guide piece extends from the side wall of the crucible to the middle part of the chamber; the second flow guide piece extends from the middle part of the chamber to the side wall of the crucible; the first flow guide and the second flow guide are located on different planes, and an atmosphere transmission channel is configured between the first flow guide and the second flow guide.

On the one hand, this crucible body can provide the water conservancy diversion effect through the setting of first water conservancy diversion spare, guarantees that carborundum gas phase component can move to the seed crystal, and on the other hand, through the cooperation of first water conservancy diversion spare and second water conservancy diversion spare, can prolong the stroke that carborundum gas phase component rises to block carbon particle to the seed crystal motion, can guarantee the growth quality of carborundum crystal.

The embodiment of the invention also provides a filling method of a silicon carbide crystal growing device, which is characterized in that a second raw material with a slower volatilization rate is filled between the first raw material and the side wall of the crucible, so that the carbonization of the raw materials is limited on an energy head, the occurrence probability of a carbon wrapping phenomenon is reduced, and the growth quality of the silicon carbide crystal is further improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of an apparatus for growing a silicon carbide crystal according to an embodiment of the present invention.

10-silicon carbide crystal growth apparatus; 101-a crucible body; 105-crucible side wall; 107-crucible bottom wall; 109-opening; 111-a chamber; 113-a first containment area; 115-a second containment area; 117-zone of inhibition; 119-silicon carbide powder; 121-silicon carbide boules; 123-cerium-containing compound powder; 125-crucible cover; 127-a seed crystal; 129-a first flow guide; 131-a first end; 133-a second end; 134-an atmosphere transfer channel; 135-inlet; 137-atmosphere transfer port; 139-a support; 141-a second flow guide; 143-a connecting end; 145-free end; 147-a flow guiding chamber; 149-a support member; 151-a feedstock chamber; 153-growth chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are absolutely horizontal or hanging, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

In the related technology, the process of growing the silicon carbide crystal is very long, which usually needs more than 100 hours, and the overflow rate of the silicon component is greater than that of the carbon component, so that the carbon component in the raw material is much greater than that of the silicon component, which is easily caused by the long time, so that the proportion of Si and C in the gas phase generated by the silicon carbide powder is unbalanced, and the silicon carbide crystal is easily carbonized. Carbon particles generated by raw material carbonization are brought to the surface of the crystal along with airflow, so that carbon packages are easily formed, the quality of the crystal is directly reduced due to the formation of the carbon packages, and quality defects such as MPD (metal-induced degradation) and polytype and the like can be induced in serious cases, so that the whole crystal is scrapped, and the loss is caused to the actual production.

In view of this, the present embodiment provides a silicon carbide growth apparatus capable of extending the ascending stroke of the gas-phase component of silicon carbide and blocking the carbon particles from moving toward the seed crystal, so as to fully ensure the growth quality of the silicon carbide crystal. The structure of the silicon carbide crystal growing apparatus is described in detail below.

Fig. 1 is a schematic structural view of a silicon carbide crystal growing apparatus 10 according to this embodiment. The present embodiment provides a silicon carbide crystal growth apparatus comprising a silicon carbide crystal growth device 10 shown in fig. 1, a heating device (not shown), a vacuum pumping device (not shown), and a shielding gas input device (not shown).

In detail, the silicon carbide crystal growing apparatus 10 is a crucible structure, which is a place where the silicon carbide crystal grows. The heating device is arranged at the periphery of the silicon carbide crystal device, can be a coil electrifying heating device and is used for heating the silicon carbide crystal growing device 10 so as to ensure that the temperature of the interior of the silicon carbide crystal growing device can reach the temperature required by the growth of the silicon carbide crystal. The vacuumizing device is used for vacuumizing the silicon carbide crystal growing device 10 so as to facilitate the silicon carbide crystal growing operation. And the protective gas input device is used for inputting inert gases such as argon and hydrogen or a mixture of hydrogen and argon as protective gas, so that the high-efficiency operation of the silicon carbide preparation is ensured.

Referring to fig. 1 again, in the present embodiment, the silicon carbide crystal growth apparatus 10 includes a crucible body 101, a plurality of first baffle members 129, a plurality of second baffle members 141, and a crucible cover 125.

Illustratively, the crucible body 101 is a cylindrical structure, which is a semi-closed cylindrical structure having an opening 109. The crucible body 101 comprises an arcuate closed crucible side wall 105 and a crucible bottom wall 107 at the end of the crucible side wall 105 remote from the opening 109, the crucible side wall 105 and the crucible bottom wall 107 enclosing a cylindrical chamber 111 communicating with the opening 109. The chamber 111 specifically comprises a raw material chamber 151 and a growth chamber 153, wherein the raw material chamber 151 is arranged close to one side of the crucible bottom wall 107 and used for placing raw materials for growing silicon carbide crystals, and the growth chamber 153 is arranged close to one side of the opening 109 and used for providing a place for growing the silicon carbide crystals. The crucible cover 125 is disc-shaped, the size of the crucible cover matches with that of the opening 109, the crucible cover can be covered on the opening 109 and close the opening 109, and the tightness and reliability of the growth operation are ensured. When the silicon carbide crystal growth operation is performed, the silicon carbide powder 119 can be placed in the chamber 111, the seed crystal 127 is arranged on one side of the crucible cover 125 facing the opening 109, and when the heating device performs the heating operation, the vapor phase formed by heating and sublimating the silicon carbide powder 119 is deposited on the surface of the seed crystal 127 to form the silicon carbide crystal.

The number of the first flow guide 129 is one or more, and in the case that there are a plurality of the first flow guide 129, the plurality of the first flow guide 129 are disposed at intervals in the growth chamber 153 of the chamber 111, and each of the first flow guide 129 extends from the crucible side wall 105 toward the middle of the chamber 111. The number of the second guide members 141 is also one or more, and when there are a plurality of the second guide members 141, the plurality of the second guide members 141 are disposed at intervals in the growth chamber 153 of the chamber 111, and each of the second guide members 141 extends from the middle of the chamber 111 toward the crucible side wall 105. And, the first guide member 129 and the second guide member 141 are located at different planes, and an atmosphere transfer passage 134 is formed between the first guide member 129 and the second guide member 141.

Through the cooperation of the first flow guide part 129 and the second flow guide part 141, the atmosphere transmission channel 134 is twisted, so that gas-phase components formed after the silicon carbide powder 119 is heated reach the seed crystal 127 along the twisted atmosphere transmission channel 134, the ascending stroke of the gas-phase components of the silicon carbide is prolonged, partial carbon particles and impurities in the atmosphere can be blocked, and the growth quality of the silicon carbide crystal is ensured.

Illustratively, by means of the first guiding element 129, the gas phase component formed after heating the silicon carbide powder 119 can be guided to move upwards to the seed crystal 127 for the silicon carbide crystal growth operation. Through the arrangement of the second flow guide part 141, the second flow guide part can be matched with the first flow guide part 129 to prolong the ascending stroke of the gas-phase component of the silicon carbide, prevent carbon particles from moving to the seed crystal 127, and simultaneously prevent impurities in the atmosphere, thereby ensuring the growth quality of the silicon carbide crystal.

Referring to fig. 1 again, in the present embodiment, at least one second flow guiding element 141 is disposed between two adjacent first flow guiding elements 129 along the direction from the crucible bottom wall 107 of the chamber 111 to the crucible cover 125, or at least one first flow guiding element 129 is disposed between two adjacent second flow guiding elements 141.

Illustratively, as shown in FIG. 1, the plurality of first baffle members 129 and the plurality of second baffle members 141 are alternately arranged in sequence in a direction from the crucible bottom wall 107 toward the crucible cover 125. Through the arrangement, the gas phase atmosphere is shielded by the second flow guide part 141 close to the crucible bottom wall 107 after passing through the first flow guide part 129 close to the crucible bottom wall 107, impurities and carbon particles in the atmosphere are removed, then the gas phase atmosphere is shielded by the second flow guide part 141 sequentially arranged next after passing through the first flow guide part 129 sequentially arranged next, and impurities and carbon packages mingled in the atmosphere are basically removed after multiple shielding, so that the occurrence probability of the carbon package condition is further reduced, and the growth quality of the silicon carbide crystal is fully ensured.

Of course, in other embodiments, when the number of the first flow guiding elements 129 is increased or decreased, the number of the second flow guiding elements 141 may also be increased or decreased, or one first flow guiding element 129 may be provided with two second flow guiding elements 141 correspondingly, or two first flow guiding elements 129 are provided with one second flow guiding element 141 correspondingly, and the like, so that the growth quality of the silicon carbide crystal can be ensured, and the description of this embodiment is omitted.

In some embodiments, the first baffle 129 is a conical baffle with openings at both ends, and for example, the baffle may be a conical structure, the first end 131 of the first baffle 129 circumferentially surrounds an inlet 135 communicating with the atmosphere transfer passage 134, the second end 133 of the first baffle 129 circumferentially surrounds an atmosphere transfer port 137 communicating with the atmosphere transfer passage 134, the atmosphere transfer port 137 is smaller than the inlet 135, the first end 131 of the baffle is far away from the opening 109, the second end 133 is close to the opening 109, and the atmosphere transfer port 137 is smaller than the inlet 135, so that the atmosphere can be guided to the atmosphere transfer port 137 via the first baffle 129.

In other embodiments, the orthographic projection surface of the second flow guide member 141 on the plane in the radial direction covers or covers and exceeds the atmosphere transmission port 137, and for example, the structure of the first flow guide member 129 is set to be a cone-shaped structure, and the second flow guide member 141 covers the atmosphere transmission port 137, so that on one hand, the flow guide of the gas-phase component sublimed at high temperature can be realized, and the effective movement of the gas-phase component towards the position of the seed crystal 127 can be ensured, so as to generate the silicon carbide crystal; on the other hand, the carbon particles can be blocked to a certain degree, so that the carbon particles fall along the extension direction of the carbon particles, and the carbon coating is further reduced, so that the quality of the silicon carbide crystal is ensured.

As an alternative embodiment, the atmosphere transfer port 137 is opposite to the middle position of the opening 109, so that the first flow guiding member 129 can guide the gas phase to move to the middle position after passing through the inlet 135 and the atmosphere transfer port 137 in sequence, so as to effectively block the carbon particles from moving while ensuring that the gas phase can reach the surface of the seed crystal 127, thereby ensuring the quality of the silicon carbide crystal.

Illustratively, the first flow guiding member 129 is in a conical structure, and the plurality of first flow guiding members 129 are arranged coaxially, so that the blocking effect and the flow guiding effect can be ensured, and the growth quality of the silicon carbide crystal can be further ensured.

Referring to fig. 1 again, in the present embodiment, a supporting body 139 for supporting the first guiding member 129 is disposed on the crucible sidewall 105. Illustratively, the support 139 may be configured as a support step having a right-angled shape and a support surface facing the opening 109, and the first end 131 of the first baffle 129 is supported on the support surface and abuts against the crucible sidewall 105 of the crucible body 101. Through the setting of supporting the step to fully guarantee the stability after first water conservancy diversion spare 129 is put into, thereby guarantee the stability of water conservancy diversion and stopping the operation, and then can fully guarantee the growth quality of silicon carbide crystal. Meanwhile, the first guide member 129 is more convenient to mount, dismount and maintain through the arrangement of the supporting steps, and the working efficiency and quality can be improved.

Alternatively, referring to fig. 1 again, in the present embodiment, the silicon carbide crystal growth apparatus 10 further includes a support 149 disposed in the chamber 111, one end of the support 149 is connected to a middle portion of each second guiding member 141, and the other end of the support 149 is connected to the bottom wall 107 of the crucible and penetrates through the atmosphere transmission channel 134. Illustratively, the support 149 is a rod-like structure; of course, in other embodiments, the support 149 may be provided as a plate or rod-like structure. Meanwhile, after the middle portion of the second baffle member 141 is connected to one end of the support member 149, the outer end of the second baffle member 141 extends toward the crucible side wall 105. The second guiding member 141 can be stabilized by the support member 149, so that the blocking effect can be ensured, and the growth quality of the silicon carbide crystal can be ensured.

In detail, in this embodiment, the second guiding elements 141 are baffles circumferentially arranged around the supporting element 149, and each of the second guiding elements 141 includes a connecting end 143 and a free end 145, the connecting end 143 is located in the middle to be fixedly connected with the supporting element 149, and the free end 145 is located in the circumferential direction and extends in a direction away from the supporting element 149.

In some embodiments, the support 149 is disposed perpendicular to the crucible bottom wall 107, and the second baffle 141 is disposed perpendicular to the support 149; alternatively, the supporting member 149 is disposed perpendicular to the bottom wall 107 of the crucible, and one end of the second guiding member 141 away from the supporting member 149 is disposed obliquely toward the bottom wall 107 of the crucible. For example, the second guiding member 141 may be specifically configured as a cone-shaped structure as shown in fig. 1, in which case the second guiding member 141 is disposed obliquely with respect to the support 149, for example, the oblique angle may be set to be between 60 ° and 90 °, and extends obliquely toward the direction of the second guiding member 141 close to the crucible bottom wall 107 to block outside the atmosphere delivery port 137, so as to effectively block the carbon particles in the gas phase structure output from the atmosphere delivery port 137, and to sufficiently ensure the growth quality of the silicon carbide crystal. Of course, in other embodiments, the second guiding element 141 can also be disposed perpendicular to the supporting element 149, and the description of this embodiment is omitted.

In the present embodiment, the support 149 is substantially located on the axis of the cylindrical crucible body 101, the second guiding member 141 is a plate-shaped structure formed by winding the support 149 as the center, and the axis of the second guiding member 141 coincides with the axis of the guiding member, so as to ensure the uniformity and reliability of the blocking operation, thereby further ensuring the growth quality of the silicon carbide crystal. Of course, in other embodiments, the supporting element 149 may also be disposed at a position close to the crucible sidewall 105, so as to ensure the stability of the second guiding element 141 and ensure the blocking effect, which is not repeated herein.

Referring again to fig. 1, in some embodiments, the chamber 111 includes a growth chamber 153 and a feedstock chamber 151 in communication with each other; the growth chamber 153 is adjacent to the side of the crucible cover 125, and the raw material chamber 151 is adjacent to the side of the crucible bottom wall 107; the first and

second guide members

129 and 141 are disposed in the growth chamber 153; the material chamber 151 includes a first receiving area 113 and a second receiving area 115 for filling different materials, wherein the second receiving area 115 is disposed around the first receiving area 113. Illustratively, the first receiving area 113 is located at a middle position opposite to the opening 109, and the second receiving area 115 is disposed around the first receiving area 113 and between the first receiving area 113 and the crucible sidewall 105. The first receiving area 113 and the second receiving area 115 are used for filling different raw materials. Here, the different materials may be different types of materials, or may be the same type but different forms of materials.

In some alternative embodiments, the first receiving area 113 is used to fill a first material and the second receiving area 115 is used to fill a second material, wherein the first material has a rate of volatilization that is greater than the rate of volatilization of the second material. Illustratively, the first receiving area may be used for filling with silicon carbide frit 119 and the second receiving area 115 may be used for filling with silicon carbide frit 121. Of course, in other embodiments, the types of the first raw material and the second raw material may be adjusted and selected according to requirements, so as to achieve the purpose of preparation, and this embodiment is not limited.

Because the crucible body 101 is when heating operation is carried out to heating device, its crucible lateral wall 105's temperature is higher, and the temperature reduces to inside gradually, and the temperature of middle part position is minimum, therefore carborundum powder 119 overflows with the silicon composition of the part of crucible lateral wall 105 contact easily for carborundum powder 119 the carbonization appears. Therefore, in the embodiment of the invention, the silicon carbide powder 119 of the silicon carbide crystal growth apparatus 10 is disposed in the first containing region 113 at the inner edge of the second containing region 115, so that the contact area between the silicon carbide powder 119 and the crucible side wall 105 of the crucible can be reduced, the probability of carbonization of the silicon carbide powder 119 can be reduced, further, the carbonization of the silicon carbide powder 119 can be limited from the source, the probability of carbon coating can be reduced, and the growth quality of the silicon carbide crystal can be fully ensured.

Meanwhile, since the silicon carbide powder 119 is easily carbonized due to the fact that the overflow rate of the silicon component is greater than that of the carbon component, and the silicon carbide crystal block 121 is in a single crystal or polycrystalline state and does not have the problem of the single overflow of the silicon component, the embodiment sets the part in contact with the wall body as the silicon carbide crystal block 121, so that the carbonization problem is not easy to occur, the growth quality of the silicon carbide crystal can be ensured, and since the carbon and silicon ratio of the silicon carbide crystal block 121 after sublimation is uniform, the uniformity of the carbon and silicon ratio in the gas phase formed after sublimation in a heated state can be ensured, and the growth quality of the silicon carbide crystal can be further ensured.

Moreover, because the temperature of the top end and the bottom end of the crucible body 101 is relatively low under the heating condition, and the temperature of the middle position of the top end and the bottom end is relatively high, the first accommodating area 113 and the second accommodating area 115 are both arranged at the positions close to the crucible bottom wall 107, the probability of carbonization of the silicon carbide powder 119 is further reduced, and the growth quality of the silicon carbide crystal is further improved.

It should be noted that, in this embodiment, the silicon carbide lump material 121 occupies 30 to 50% of the inner diameter of the crucible body 101 along the radial laying thickness of the crucible body 101, the filling thickness is not less than 50mm, and the filling height is 40 to 90mm, and this occupying ratio and size setting can achieve the effect of uniform temperature gradient, so that more uniform temperature gradient distribution can be realized at the top of the silicon carbide powder 119, and the growth quality of the silicon carbide crystal can be fully ensured. Of course, in other embodiments, the size and the ratio of the filling may be adjusted according to the requirement, so as to ensure the growth quality of the silicon carbide crystal, and this embodiment is not described again.

In addition, when the first raw material and the second raw material are the same type of raw material having different forms, for example, both are made of silicon carbide, and other impurities in the atmosphere can be reduced.

Optionally, in this embodiment, an orthographic projection area of the first flow guiding element 129 on the plane in the radial direction covers or covers and exceeds an orthographic projection area of the second accommodating area 115 on the plane in the radial direction. Through the arrangement, the blocking and flow guiding effects can be fully ensured, so that the growth quality of the silicon carbide crystal is ensured.

Further optionally, the raw material chamber 151 of the chamber 111 further includes a suppression area 117 located between the bottom end of the first accommodation area 113 and the crucible bottom wall 107 of the crucible body 101, the second accommodation area 115 is disposed around the first accommodation area 113 and the suppression area 117, and the suppression area 117 is used for placing the cerium-containing compound powder 123. On one hand, the silicon carbide powder 119 is not in contact with the bottom wall 107 of the crucible through the arrangement of the inhibition area 117, so that the silicon carbide powder 119 is not in direct contact with the wall body of the crucible body 101, the probability of occurrence of carbonization can be further reduced, and the growth quality of the silicon carbide crystal is ensured; on the other hand, cerium-containing compound powder 123 can be arranged in the inhibition area 117, and when cerium atoms of the cerium-containing compound powder 123 enter a crystal growth interface, the temperature of the growth interface can be reduced, and the surface energy of the growth interface can be reduced, so that the growth of a 4H-SiC crystal is facilitated; meanwhile, the cerium atoms enter the crystal growth interface, so that the content ratio of the carbon element to the silicon element can be improved, the crystal is stabilized in a 4H crystal form, the probability of carbonization can be further reduced, carbon coating is reduced, and the growth quality of the silicon carbide crystal is ensured.

That is, by using the suppression region 117 and the cerium-containing compound powder 123, it is possible to prevent the occurrence of polytypes in the crystal without affecting the crystal growth and suppressing carbon inclusions, and it is also possible to further ensure the growth quality of the silicon carbide crystal.

In this embodiment, the cerium-containing compound powder 123 is specifically selected from cerium oxide and the like, and the cerium oxide can prevent the generation of polytype in the crystal without affecting the crystal growth and inhibiting the carbon coating.

In this embodiment, no clear partition is provided between the first housing area 113, the suppression area 117, and the second housing area 115, and when the raw material is loaded, the bulk silicon carbide crystal blocks 121 may be loaded first, the cerium-containing compound powder 123 may be loaded further in the middle of the silicon carbide crystal blocks 121, and finally the silicon carbide powder 119 may be uniformly spread over the cerium-containing compound powder 123. In other embodiments, a graphite partition (not shown) may be disposed between the first accommodating region 113, the suppressing region 117, and the second accommodating region 115 to divide the regions, which is not described in detail in this embodiment.

In addition, it should be noted that in the present embodiment, the diameters of the first receiving area 113 and the suppressing area 117 are set to be the same, and the silicon carbide powder 119 is filled to be flush with the silicon carbide crystal block 121, so as to sufficiently ensure the quality and efficiency of the silicon carbide crystal growing operation.

Referring again to FIG. 1, in some embodiments, the inner edge of the crucible side wall 105 at the end remote from the crucible bottom wall 107 is sloped relative to the axial direction and tapers in a direction toward the crucible cover 125 and encloses a baffle chamber 147. Illustratively, the inner edge of the crucible side wall 105 of the crucible body 101 near the opening 109 can be arranged to be inclined relative to the axial direction and gradually tightened in the direction toward the crucible cover 125 to form a flow guiding chamber 147 in a surrounding manner, so as to guide the gas phase after being guided by the flow guiding hood and blocked by the baffle plate to the seed crystal 127, thereby ensuring the growth quality and the growth efficiency of the silicon carbide crystal.

Illustratively, the silicon carbide crystal growing apparatus 10 further comprises a plurality of graphite soft felt insulating layers wrapped outside the crucible body 101 and the crucible cover 125 to provide an insulating function and ensure the growth efficiency and quality.

Referring again to FIG. 1, the present embodiment also provides a method for loading a silicon carbide crystal growth apparatus 10, the silicon carbide crystal growth apparatus 10 comprising: the crucible comprises a crucible body 101, a crucible cover 125, a plurality of first flow guide pieces 129 and a plurality of second flow guide pieces 141; the crucible body 101 comprises a crucible bottom wall 107 and a crucible side wall 105, a cavity 111 is formed by enclosing the crucible bottom wall 107 and the crucible side wall 105, the crucible cover 125 is covered on one side of the crucible side wall 105 opposite to the crucible bottom wall 107, the cavity 111 comprises a growth cavity 153 and a raw material cavity 151 which are communicated with each other, the growth cavity 153 is close to one side of the crucible cover 125, the raw material cavity 151 is close to one side of the crucible bottom wall 107, the raw material cavity 151 comprises a first containing area 113 and a second containing area 115, and the second containing area 115 is arranged outside the first containing area 113 in a winding manner; the first baffle 129 extends from the crucible side wall 105 toward the middle of the chamber 111; the second baffle 141 extends from the middle of the chamber 111 towards the crucible side wall 105; the first flow guide 129 and the second flow guide 141 are configured as an atmosphere transfer passage therebetween; the filling method specifically comprises the following steps:

s1: filling the first containing area 113 with a first raw material;

s2: the second containing area 115 is filled with a second raw material, the first raw material and the second raw material are different raw materials, and the volatilization rate of the first raw material is greater than that of the second raw material.

Illustratively, the first material and the second material may be selected from the same material in different forms, wherein the first material may be selected from the group consisting of silicon carbide powder 119, and the second material may be selected from the group consisting of silicon carbide bulk 121.

Specifically, step S1 and step S2 are not in the order of priority, and step S1 may be performed first, or step S2 may be performed first. Simultaneously, because the crucible body 101 is when heating operation is carried out to heating device, its crucible lateral wall 105's temperature is higher, and the temperature reduces inside gradually, and the temperature of middle part position is minimum, therefore carborundum powder 119 overflows with the silicon composition of the part of crucible lateral wall 105 contact easily for carborundum powder 119 the carbonization appears. The reason why the silicon carbide powder 119 is easily carbonized is that the overflow rate of the silicon component is larger than that of the carbon component, while the silicon carbide crystal block 121 does not have a problem that the silicon component is separately overflowed because it is in a single crystal or polycrystal form. Therefore, in the embodiment, the silicon carbide powder 119 of the silicon carbide crystal growth apparatus 10 is disposed in the first accommodation region 113 at the inner edge of the second accommodation region 115, and the silicon carbide crystal block 121 is disposed in the second accommodation region 115, so that the contact area between the silicon carbide powder 119 and the crucible side wall 105 of the crucible can be reduced, the probability of carbonization of the silicon carbide powder 119 can be reduced, further, the carbonization of the silicon carbide powder 119 can be limited from the source, the probability of carbon wrapping phenomenon can be reduced, and the growth quality of the silicon carbide crystal can be fully ensured.

Optionally, the method for loading the silicon carbide crystal growth apparatus 10 further comprises loading the cerium-containing compound powder 123 in the first containing region 113 before loading the silicon carbide powder 119 in the first containing region 113, so that the cerium-containing compound powder 123 is located between the silicon carbide powder 119 and the crucible bottom wall 107, thereby avoiding the generation of polytype in the crystal without affecting the crystal growth and inhibiting the carbon inclusion during the preparation process, and further ensuring the growth quality of the silicon carbide crystal.

The installation process, the working principle and the beneficial effects of the silicon carbide crystal growth equipment provided by the invention are described in detail as follows:

when the silicon carbide crystal growth equipment is assembled, the silicon carbide crystal growth device 10 can be assembled, and then the heating device, the vacuumizing device, the shielding gas input device and the like are sequentially connected. When assembling the silicon carbide crystal growing apparatus 10, the silicon carbide crystal blocks 121 are first placed in the second containing region 115, then the cerium-containing compound powder 123 is placed in the inhibition region 117, and the silicon carbide powder 119 is uniformly spread in the first containing region 113 above the inhibition region 117; then, the crucible cover 125 adhered with the 4H-SiC seed crystal 127 is covered, and after the graphite soft felt heat preservation layer is wrapped around the crucible cover 125 and the crucible body 101, the growth operation can be carried out, so as to obtain the 4H-SiC crystal and the wafer. The obtained 4H-SiC crystal and wafer have no visible defect when observed by naked eyes, no polycrystal at the edge, no carbon inclusion under strong light and a polariscope, and no polytype discovery under the irradiation of a UV lamp.

In the above process, on the one hand, the silicon carbide crystal growth device 10 adopts a special filling process, the silicon carbide powder 119 is arranged in the first containing area 113 formed by the second containing area 115, so that the contact area between the silicon carbide powder 119 and the wall body of the crucible can be reduced, the temperature of the wall body of the crucible is higher than that of the central area, and the silicon carbide powder 119 is more easily carbonized, so that the probability of carbonization of the silicon carbide powder 119 can be reduced by reducing the contact area between the silicon carbide powder 119 and the wall body, further, the carbonization of the silicon carbide powder 119 can be limited from the source, the probability of the carbon wrapping phenomenon is reduced, and the growth quality of the silicon carbide crystal is fully ensured. On the other hand, through the cooperation of the first diversion part 129 and the second diversion part 141, the gas phase components sublimed at high temperature can be blocked for a plurality of times, so as to remove carbon particles ascending along with the gas phase and impurities in the raw materials, and further ensure the growth quality of the silicon carbide crystal. Meanwhile, cerium-containing compound powder 123 is also arranged, so that the generation of polytype in the crystal can be avoided by adding the cerium-containing compound powder 123 without influencing the crystal growth and inhibiting the carbon coating, and the growth quality of the silicon carbide crystal can be further ensured.

In summary, the embodiments of the present invention provide a silicon carbide crystal growth apparatus 10 and device capable of reducing the occurrence of carbonization of silicon carbide powder 119, which can limit the carbonization of the raw material and reduce the occurrence probability of carbon coating phenomenon, so as to fully ensure the growth quality of the silicon carbide crystal.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An apparatus for growing a silicon carbide crystal, comprising:

the crucible body comprises a crucible bottom wall and a crucible side wall, and a cavity is formed by enclosing the crucible bottom wall and the crucible side wall;

a plurality of second flow guide pieces extending from the middle part of the chamber to the side wall of the crucible;

2. A silicon carbide crystal growth apparatus according to claim 1 wherein:

at least one second flow guide piece is arranged between every two adjacent first flow guide pieces along the direction from the bottom wall of the crucible to the crucible cover, or at least one first flow guide piece is arranged between every two adjacent second flow guide pieces.

3. A silicon carbide crystal growth apparatus according to claim 1 wherein:

first water conservancy diversion spare court the crucible cover place direction slope sets up, just first water conservancy diversion spare is kept away from the one end of crucible lateral wall enclose close form with the atmosphere transmission mouth of atmosphere transmission path intercommunication, the orthographic projection area of second water conservancy diversion spare on radial direction place plane covers or covers and surpasss atmosphere transmission mouth.

4. The silicon carbide crystal growth apparatus of claim 1, wherein: the growing apparatus further comprises:

and one end of the supporting piece is connected with the middle part of the second flow guide piece, and the other end of the supporting piece is connected with the bottom wall of the crucible and penetrates through the atmosphere transmission channel.

5. A silicon carbide crystal growth apparatus according to claim 4 wherein:

the supporting piece is arranged perpendicular to the bottom wall of the crucible, and the second flow guide piece is arranged perpendicular to the supporting piece; or the supporting piece is perpendicular to the bottom wall of the crucible, and one end, far away from the supporting piece, of the second flow guide piece is obliquely arranged towards the direction of the bottom wall of the crucible.

6. A silicon carbide crystal growth apparatus according to claim 1 wherein:

and a support body for supporting the first flow guide piece is arranged on the side wall of the crucible.

7. The silicon carbide crystal growth apparatus of claim 1, wherein:

the inner edge of the side wall of the crucible at one end far away from the bottom wall of the crucible inclines relative to the axial direction, and gradually tightens in the direction towards the crucible cover and encloses a flow guide chamber.

8. A silicon carbide crystal growth apparatus according to any one of claims 1 to 7 wherein:

the chamber comprises a growth chamber and a raw material chamber which are communicated with each other; the growth chamber is close to one side of the crucible cover, and the raw material chamber is close to one side of the crucible bottom wall;

9. A silicon carbide crystal growing apparatus according to claim 8 wherein:

the orthographic projection surface of the first flow guide piece on the plane where the radial direction is located covers or covers and exceeds the orthographic projection surface of the second accommodating area on the plane where the radial direction is located.

10. A method of loading a silicon carbide crystal growing apparatus, the silicon carbide crystal growing apparatus comprising: the crucible comprises a crucible body, a crucible cover, a plurality of first flow guide pieces and a plurality of second flow guide pieces; the crucible body comprises a crucible bottom wall and a crucible side wall, a cavity is formed by enclosing the crucible bottom wall and the crucible side wall, the crucible cover is arranged on one side of the crucible side wall opposite to the crucible bottom wall, the cavity comprises a growth cavity and a raw material cavity which are communicated with each other, the growth cavity is close to one side of the crucible cover, the raw material cavity is close to one side of the crucible bottom wall, the raw material cavity comprises a first containing area and a second containing area, and the second containing area is wound outside the first containing area; the first flow guide piece extends from the side wall of the crucible to the middle part of the chamber; the second flow guide extends from the middle part of the chamber to the side wall of the crucible; the first flow guide piece and the second flow guide piece are positioned on different planes, and an atmosphere transmission channel is arranged between the first flow guide piece and the second flow guide piece;

the filling method comprises the following steps:

filling a first raw material in the first accommodating area;

11. The method of loading a silicon carbide crystal growing apparatus as defined in claim 10 wherein:

the first raw material and the second raw material are the same raw material with different forms;

the first raw material is silicon carbide powder, and the second raw material is silicon carbide lump material.

12. The method of loading a silicon carbide crystal growing apparatus defined in claim 10 wherein prior to loading the first feedstock material into the first containment zone, the method further comprises:

and filling cerium-containing compound powder in the first accommodating area.