TWM673590U - Silicon carbide manufacturing equipment - Google Patents

Abstract

A silicon carbide manufacturing apparatus comprises a graphite crucible, a diffusion plate unit, and a coating unit. The graphite crucible includes a bottom wall, a first peripheral wall extending upward from the periphery of the bottom wall, and a second peripheral wall extending upward from the top of the first peripheral wall. The bottom wall, the first peripheral wall, and the second peripheral wall together define a chamber with an opening. The chamber has a raw material area defined by the bottom wall and the first peripheral wall, and a sublimation zone located between the raw material area and the opening. The diffusion plate unit includes a plurality of diffusion plates arranged in an annular pattern and spaced vertically within the sublimation zone. The diffusion plates accommodate multiple carbon sources. The coating unit includes a first coating layer on a surface of the first peripheral wall facing the raw material area, and a second coating layer on a surface of the second peripheral wall facing the sublimation area.

Description

Silicon carbide manufacturing equipment

The present invention relates to a silicon carbide manufacturing device, in particular to a silicon carbide manufacturing device capable of increasing the carbon source contact area.

Third-generation semiconductor materials (such as silicon carbide and gallium nitride) are primarily produced using physical vapor deposition (PVD). PVD powder production involves placing a silicon source at the bottom of a crucible and attaching a carbon source to a lid atop the crucible. The crucible is then heated using electromagnetic induction, causing the silicon source to sublime into a gas that is transported upward (toward the top of the crucible) to the carbon source, forming silicon carbide (SiC).

However, due to the current's concentration effect, the heat energy generated by electromagnetic induction is primarily concentrated on the crucible's walls, resulting in uneven heating of the silicon source. For example, when the crucible is heated to 2100-2400°C, a radial temperature gradient forms on the surface of the silicon powder. The lowest point of this temperature gradient is located where the silicon carbide powder corresponds to the crucible's central axis. This reduces the efficiency of the silicon source. Therefore, improving this problem is an important topic.

Therefore, one of the objectives of the present invention is to provide a silicon carbide manufacturing device that can solve at least one of the above problems.

Therefore, the novel silicon carbide manufacturing apparatus includes a graphite crucible, including a bottom wall, a first peripheral wall extending upward along the periphery of the bottom wall, and a second peripheral wall extending upward from the top of the first peripheral wall, wherein the bottom wall, the first peripheral wall, and the second peripheral wall jointly define a chamber having an opening, wherein the chamber has a raw material area defined by the bottom wall and the first peripheral wall, and a sublimation zone located between the raw material area and the opening; a diffusion plate unit, including a plurality of diffusion plates annularly arranged in the sublimation zone at intervals of one another, wherein the diffusion plates are used to place a plurality of carbon sources; and a coating unit, including a first coating layer located on a surface of the first peripheral wall facing the raw material area, and a second coating layer located on a surface of the second peripheral wall facing the sublimation zone.

In some embodiments, a porous graphite tube is further included in the raw material area.

In some embodiments, the diffusion plates include a first diffusion plate disposed at the bottom of the sublimation zone and two second diffusion plates located above the first diffusion plate.

In some embodiments, the first diffusion disk has a first opening, each of the second diffusion disks has a second opening, and the diameter of the first opening is larger than the diameter of the second opening.

In some embodiments, the diameter of the first opening is larger than the diameter of the porous graphite tube.

In some embodiments, the thickness of the first coating layer is less than the thickness of the second coating layer.

In some embodiments, the material of the first coating layer and the second coating layer comprises metal carbide.

In some embodiments, the metal carbide is selected from tantalum carbide, einsteinium carbide, or zirconium carbide.

The present invention has at least the following effects: by disposing the diffusion plates of the diffusion plate unit in the sublimation zone at intervals above and below, the contact area of the carbon source placed on the diffusion plates can be increased, thereby increasing the overall efficiency of silicon carbide generation.

Referring to Figure 1 , the novel silicon carbide manufacturing apparatus is suitable for utilizing a carbon source (not shown) and a silicon source 101 to produce powdered silicon carbide (SiC) (not shown). The silicon source 101 may be, for example, silicon powder, silicon dioxide (SiO ₂ ), silicon sand, or other silicon-containing raw materials, and the carbon source may be, for example, carbon powder, petroleum coke, or other carbon-containing raw materials. However, in actual implementation, there are no particular limitations on the carbon source and silicon source 101. One embodiment of the novel silicon carbide manufacturing apparatus includes a graphite crucible 1, a diffusion plate unit 3, a coating unit 2, a graphite cover 4, a porous graphite tube 5, and a heating unit 6.

The graphite crucible 1 includes a bottom wall 11, a first peripheral wall 12 extending upward from the periphery of the bottom wall 11, and a second peripheral wall 13 extending upward from the top of the first peripheral wall 12. The bottom wall 11, the first peripheral wall 12, and the second peripheral wall 13 collectively define a chamber 14 with an opening 15. The chamber 14 includes a raw material zone defined by the bottom wall 11 and the first peripheral wall 12, and a sublimation zone located between the raw material zone and the opening 15. The raw material zone is suitable for accommodating the silicon source 101. The graphite upper cover 4 is openably disposed on the top of the second peripheral wall 13 to seal the opening 15. The temperature of the raw material zone is set between 2200°C and 2300°C, while the sublimation zone is set to approximately 2100°C.

The coating unit 2 is designed to conserve heat, prevent heat loss, and provide corrosion resistance. It includes a first coating layer 21 located on the surface of the first peripheral wall 12 in the raw material zone, and a second coating layer 22 located on the surface of the second peripheral wall 13 in the sublimation zone. Both the first coating layer 21 and the second coating layer 22 are made of metal carbides selected from tantalum carbide, arsenic carbide, or zirconium carbide. The thickness of the first coating layer 21 is smaller than that of the second coating layer 22, ensuring better thermal insulation in the sublimation zone.

Referring to Figures 1 and 2 , the diffusion plate unit 3 comprises a plurality of diffusion plates arranged in a circular pattern, spaced vertically within the sublimation zone. These diffusion plates accommodate multiple carbon sources. Specifically, the diffusion plates include a first diffusion plate 31 positioned at the bottom of the sublimation zone and two second diffusion plates 32 positioned above the first diffusion plate 31. The first diffusion plate 31 has a first opening 15, and each second diffusion plate 32 has a second opening 15. The diameter of the first opening 15 is larger than that of the second opening 15. The porous graphite tube 5 is located in the raw material zone to filter impurities generated during the heating and sublimation process of the silicon source 101, preventing these impurities from being mixed with the sublimation gas and transported to the carbon source for deposition. Preferably, the porous graphite tube 5 is approximately 20-30 mm thick, with a pore diameter of approximately 300 to 1000 µm. Furthermore, the first opening 15 has a larger diameter than the porous graphite tube 5. The heating unit 6 includes three first heat sources 61 located near the bottom wall 11 and the first peripheral wall 12, and two second heat sources 62 located on the second peripheral wall 13. The first heat sources 61 are used to heat the raw material zone, while the second heat sources 62 are used to heat the sublimation zone.

The operating process of the novel silicon carbide manufacturing apparatus is generally as follows: Under high temperature conditions, the silicon source 101 located in the raw material zone sublimates into silicon vapor. After being filtered through the porous graphite tube 5, the silicon vapor diffuses upward, reacting with the carbon source on the diffusion plates. By disposing the diffusion plates of the diffusion plate unit 3 in the sublimation zone, the contact area of the carbon source placed on the diffusion plates is increased, thereby increasing the overall efficiency of silicon carbide production. The carbon source on the diffusion plates is also more evenly exposed to the silicon vapor, reducing the size variation of the resulting silicon carbide (SiC) particles. During the reaction process, inert gas is added as a reaction catalyst, which can also increase the overall efficiency of silicon carbide formation.

In summary, the novel silicon carbide production apparatus, by disposing the diffusion plates of the diffusion plate unit 3 at intervals in the sublimation zone, can increase the contact area of the carbon source placed on the diffusion plates, thereby increasing the overall efficiency of silicon carbide production, thereby truly achieving the purpose of this novel apparatus.

However, the above description is merely an example of the present invention and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made within the scope of the patent application and the content of the patent specification are still within the scope of the present patent.

101: Silicon source 1: Graphite crucible 11: Bottom wall 12: First peripheral wall 13: Second peripheral wall 14: Chamber 15: Opening 2: Coating unit 21: First coating layer 22: Second coating layer 3: Diffusion plate unit 31: First diffusion plate 32: Second diffusion plate 4: Graphite cover 5: Porous graphite tube 6: Heating unit 61: First heat source 62: Second heat source

Other features and benefits of the present invention are clearly illustrated in the accompanying drawings, including: Figure 1 is a schematic cross-sectional view of an embodiment of the present invention's silicon carbide manufacturing apparatus; and Figure 2 is a schematic perspective view of a diffusion plate unit and a porous graphite tube of the embodiment.

101: Silicon Source

1: Graphite Crucible

11: Bottom wall

12: First wall

13: Second peripheral wall

14: Storage Room

15: Opening

2: Coating unit

21: First coat

22: Second coating

3: Diffuser unit

31: First Diffusion Plate

32: Second diffusion plate

4: Upper cover

5:Porous graphite tube

6: Heating unit

61: First Heat Source

62: Second heat source

Claims (8)

A silicon carbide manufacturing apparatus comprises: A graphite crucible comprising a bottom wall, a first peripheral wall extending upwardly from the periphery of the bottom wall, and a second peripheral wall extending upwardly from the top of the first peripheral wall. The bottom wall, the first peripheral wall, and the second peripheral wall collectively define a chamber having an opening. The chamber comprises a raw material region defined by the bottom wall and the first peripheral wall, and a sublimation region located between the raw material region and the opening; A diffusion plate unit comprising a plurality of diffusion plates annularly arranged and spaced vertically within the sublimation region, the diffusion plates housing a plurality of carbon sources; and A coating unit comprising a first coating layer on a surface of the first peripheral wall facing the raw material region, and a second coating layer on a surface of the second peripheral wall facing the sublimation region. The silicon carbide manufacturing apparatus as described in claim 1 further includes a porous graphite tube arranged in the raw material area. The silicon carbide manufacturing apparatus as described in claim 2, wherein the diffusion plates include a first diffusion plate disposed at the bottom of the sublimation zone and two second diffusion plates located above the first diffusion plate. The silicon carbide manufacturing apparatus as described in claim 3, wherein the first diffusion plate has a first opening, each of the second diffusion plates has a second opening, and the diameter of the first opening is larger than the diameter of the second opening. The silicon carbide manufacturing apparatus as described in claim 4, wherein the diameter of the first opening is larger than the diameter of the porous graphite tube. The silicon carbide manufacturing apparatus as described in claim 1, wherein a thickness of the first coating layer is smaller than a thickness of the second coating layer. The silicon carbide manufacturing apparatus according to claim 1, wherein the material of the first coating layer and the second coating layer comprises metal carbide. The silicon carbide manufacturing apparatus as described in claim 7, wherein the metal carbide is selected from tantalum carbide, einsteinium carbide or zirconium carbide.