Ceramic ring and graphite boat

Abstract

The utility model provides a ceramic ring and a graphite boat, and belongs to the technical field of solar cell manufacturing, the ceramic ring comprises a ceramic ring body, the outer surface of the ceramic ring body is provided with an annular narrow slit, and the annular narrow slit obliquely extends into the ceramic ring body, so that the inner wall of the annular narrow slit forms a circular truncated cone side surface. According to the ceramic ring and the graphite boat provided by the utility model, the annular narrow slit arranged on the outer surface of the ceramic ring body obliquely extends into the ceramic ring body to form a circular truncated cone side surface and form a narrow inclined slit, so that reaction gas is difficult to enter, and the probability of deposition of amorphous silicon in the annular narrow slit can be reduced; the amount of amorphous silicon deposited on the inner surface of the groove of the ceramic ring is reduced, and an amorphous silicon layer deposited on the surface of the ceramic ring body is separated, so that an amorphous silicon conductive layer which is continuous in the axial direction is prevented from being deposited on the circumferential surface of the ceramic ring body, the probability of conduction and short circuit of two adjacent graphite boat pages is reduced, the risk of damage of the graphite boat pages is reduced, and the service life of the graphite boat pages is prolonged. And the yield and the productivity of the silicon wafer are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of solar cell manufacturing, and particularly relates to a ceramic ring and a graphite boat provided with the ceramic ring. Background Art

[0002] The Topcon cell is a solar cell based on the principle of selective carriers. Currently, there are four main processes for preparing the tunnel oxide layer in the Topcon cell: LPCVD, PVD, PECVD, and PEALD. Among them, the two in-situ doping processes of PECVD and PEALD both require the use of a graphite boat.

[0003] A graphite boat serves as a carrier for PECVD coating of solar silicon wafers. During coating, the boat, loaded with the wafers to be coated, is placed into the PECVD vacuum coating equipment to coat the wafers with phosphorus-doped amorphous silicon. The graphite boat consists of an insulating ceramic ring and two graphite boat pages that hold the solar silicon wafers. The insulating ceramic ring abuts between the two graphite boat pages to ensure the required spacing between them. It also insulates the two graphite boat pages, which are connected to different electrodes, creating an electric field between them, thereby depositing the amorphous silicon layer on the silicon wafer.

[0004] When using PECVD to plate good conductor films such as doped amorphous silicon, a conductive film will be deposited on the ceramic ring. As the ceramic ring is used more and more times and the time of use increases, the insulating properties of the ceramic ring will gradually decrease, eventually causing the ceramic ring to become a conductor, causing conduction between the positive and negative plates of the graphite boat, causing process instability problems, resulting in reduced product quality, lower yield and increased rework rate. Utility Model Content

[0005] The embodiments of the present invention provide a ceramic ring and a graphite boat, which are intended to delay the time for depositing a conductive film on the ceramic ring, extend the insulation service life of the ceramic ring, and prevent conduction between the positive and negative plates of the graphite boat, which would cause problems such as reduced product quality, decreased yield, and increased rework rate.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a ceramic ring, including: a ceramic ring body, an annular narrow slot is provided on the outer surface of the ceramic ring body, and the annular narrow slot extends obliquely into the ceramic ring body so that the inner wall of the annular narrow slot constitutes the side of a truncated cone.

[0007] In combination with the first aspect, in one achievable manner, the shortest distance L1 between the opening of the annular slit and the axial end of the ceramic ring body is 1-2 mm.

[0008] In combination with the first aspect, in one achievable manner, the shortest distance L2 between the bottom of the annular narrow slot and the axial end of the ceramic ring body is 1-1.5 mm.

[0009] In combination with the first aspect, in one achievable manner, the shortest distance L3 between the bottom of the annular narrow slot and the inner wall of the ceramic ring body is 1-1.5 mm.

[0010] In combination with the first aspect, in one achievable manner, the groove width L4 of the annular narrow slit is 0.5-1.0 mm.

[0011] In combination with the first aspect, in one achievable manner, the groove wall surface of the annular narrow slot close to the center line of the ceramic ring body has a rough structure.

[0012] In combination with the first aspect, in one achievable manner, the rough structure includes spiral protrusions spirally formed on the circumferential surface of the ceramic ring body.

[0013] In combination with the first aspect, in one achievable manner, the axial cross-section of the spiral protrusion is triangular, rectangular, arc-shaped or trapezoidal.

[0014] In a second aspect, an embodiment of the present invention further provides a graphite boat provided with the ceramic ring.

[0015] The ceramic ring and graphite boat provided by the present invention have the following beneficial effects compared with the prior art: the annular narrow slit arranged on the outer surface of the ceramic ring body is inclined and penetrates into the ceramic ring body to form a truncated cone side, forming a narrow inclined gap, which makes it difficult for the reaction gas to enter, and can reduce the probability of amorphous silicon deposition inside the annular narrow slit, reduce the amount of amorphous silicon deposited on the inner surface of the ceramic ring groove, and isolate the amorphous silicon layer deposited on the surface of the ceramic ring body, thereby avoiding the deposition of an amorphous silicon conductive layer continuous along the axial direction on the circumferential surface of the ceramic ring body, thereby reducing the probability of conduction and short circuit between two adjacent graphite boat pages, reducing the risk of damage to the graphite boat pages, and allowing the deposition of the amorphous silicon layer of the silicon wafer to proceed normally, thereby improving the yield and production capacity of the silicon wafer; at the same time, it can extend the effective insulation service life of the ceramic ring as an insulator. Since the service life of the ceramic ring is extended, the time and cost of replacing the ceramic ring can also be reduced, which is also conducive to shortening the production cycle and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a ceramic ring provided in an embodiment of the present utility model;

[0017] Figure 2 for Figure 1 A schematic side view of the structure of the provided ceramic ring;

[0018] Description of reference numerals:

[0019] 1. Ceramic ring body; 2. Rough structure; 3. Annular slit; 4. Center hole; 5. Bottom of the annular slit. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] Please also refer to Figure 1 and Figure 2 The ceramic ring provided by the present invention is now described. The ceramic ring comprises a ceramic ring body 1, an annular slit 3 is provided on the outer surface of the ceramic ring body 1, and the annular slit 3 extends obliquely into the ceramic ring body 1 so that the inner wall of the annular slit 3 forms a truncated cone side surface.

[0022] The ceramic ring and graphite boat provided by the present invention have an annular narrow slit 3 arranged on the outer surface of the ceramic ring body 1, which is inclined and penetrates into the ceramic ring body 1 to form a truncated cone side surface, forming a narrow inclined gap, which makes it difficult for the reaction gas to enter, and can reduce the probability of amorphous silicon deposition inside the annular narrow slit 3, reduce the amount of amorphous silicon deposited on the inner surface of the ceramic ring groove, and isolate the amorphous silicon layer deposited on the surface of the ceramic ring body 1, thereby preventing the circumferential surface of the ceramic ring body 1 from being deposited into an amorphous silicon conductive layer continuous along its axial direction, thereby reducing the probability of conduction and short circuit between two adjacent graphite boat pages, reducing the risk of damage to the graphite boat pages, and allowing the deposition of the amorphous silicon layer of the silicon wafer to proceed normally, thereby improving the yield and production capacity of the silicon wafer; at the same time, it can extend the effective insulation service life of the ceramic ring as an insulator. Since the service life of the ceramic ring is extended, the time and cost of replacing the ceramic ring can also be reduced, which is also conducive to shortening the production cycle and reducing production costs.

[0023] When the present invention is in use, under the premise that the external dimensions of the ceramic ring body 1 are certain, the depth of the annular narrow gap 3 is relatively deep, so that it is difficult for sediment to enter the annular narrow gap 3 and adhere to its inner surface, especially the inner surface of the annular narrow gap 3 close to the inner surface of the inner wall of the ceramic ring body, so that the amorphous silicon conductive layer deposited on the outer surface of the ceramic ring body 1 forms a partition at the annular narrow gap 3, so that the insulation effect between the two axial end faces of the ceramic ring body 1 is very ideal; after testing, conventional ceramic rings need to be taken offline for cleaning after 40 uses, while the ceramic ring of the present invention can be used up to 80 times before being taken offline for cleaning, which effectively reduces the probability of sediment accumulation inside the annular narrow gap 3 and extends the one-time service life of the ceramic ring, thereby not only reducing the cost of use, but also reducing the frequency of replacing ceramic rings, and ensuring the continuity of amorphous silicon deposition on silicon wafers.

[0024] It should be noted that, since ceramic rings are generally cylindrical, the axial direction referred to in this application refers to the direction of the centerline of the ceramic ring body 1, and the circumferential outer surface of the ceramic ring is the circumferential outer surface. Therefore, generally speaking, the axial cross-section of the annular narrow slot is an eight-shaped shape.

[0025] The ceramic ring body 1 is provided with a center hole 4, and the ceramic ring body 1 needs to be inserted into the ceramic column so that the ceramic column can pass through; the graphite boat includes multiple ceramic columns, multiple graphite boat pages and multiple ceramic rings, each graphite boat page is provided with a fixed through hole, and the ceramic column passes through the fixed through hole of each graphite boat page to fix the multiple graphite boat pages. The ceramic ring is provided on the ceramic column to support and isolate two adjacent graphite boat pages.

[0026] In some embodiments, see Figure 1 As shown, the shortest distance L1 between the opening of the annular narrow slit 3 and the axial end of the ceramic ring body 1 is 1-2 mm. For example, L1 can be 1 mm, 1.5 mm, or 2 mm.

[0027] In some embodiments, see Figure 1 and Figure 2 As shown, the shortest distance L2 between the bottom 5 of the annular slit and the axial end of the ceramic ring body 1 is 1-1.5 mm. For example, L2 can be 1 mm, 1.2 mm, or 1.5 mm. The axial length of a ceramic ring is generally 11 mm to 13 mm. By limiting the opening of the annular slit 3 and the shortest distance between the bottom of the annular slit and the axial ends of the ceramic ring body 1, the present application can set an annular slit 3 of maximum depth on the ceramic ring body 1, thereby increasing the difficulty of depositing an amorphous silicon layer inside the annular slit 3 and extending the primary service life of the ceramic ring.

[0028] In some embodiments, see Figure 1 As shown, the minimum distance L3 between the bottom of the annular slit 3 and the inner wall of the ceramic ring body 1 is 1-1.5 mm. For example, L3 can be 1 mm, 1.2 mm, or 1.5 mm. By limiting the minimum distance between the bottom of the annular slit 3 and the inner wall of the ceramic ring body 1, the present application forms an annular slit 3 with a large inclination within the allowable range, thereby increasing the difficulty of depositing the amorphous silicon layer within the annular slit 3 and extending the primary service life of the ceramic ring.

[0029] In some embodiments, see Figure 1 As shown, the slot width L4 of the annular narrow slot 3 is 0.5-1.0 mm. The present application increases the difficulty of depositing the amorphous silicon conductive layer inside the annular narrow slot 3 by limiting the width of the annular narrow slot 3, thereby extending the life of the ceramic ring.

[0030] In some embodiments, see Figure 1As shown, the groove wall surface of the annular narrow slot 3 near the centerline of the ceramic ring body 1 has a rough structure 2. The provision of the rough structure 2 makes it difficult to form a conductive layer on the inner surface or groove wall of the annular narrow slot 3, and thus it is impossible to form a conductive layer that is connected at both ends of the axial direction on the outer surface of the ceramic ring, thereby achieving insulation between the two graphite boat pages.

[0031] In some embodiments, see Figure 1 As shown, the rough structure 2 includes spiral protrusions spirally formed on the circumferential surface of the ceramic ring body 1, the purpose of which is to extend the period of forming the conductive layer of the ceramic ring. The spiral protrusions can be a thread structure.

[0032] In some embodiments, the axial cross-section of the spiral protrusion is triangular, rectangular, arc-shaped, or trapezoidal.

[0033] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0034] Based on the same inventive concept, embodiments of the present application also provide a graphite boat equipped with the aforementioned ceramic rings. Because the ceramic rings employed have a long insulation lifespan, the risk of conductive layer deposition on the outer surface of the inner ceramic rings causing conduction in the graphite boat can be reduced, thereby improving product quality and yield, reducing the rework rate of coated products, and also reducing the time and expense of replacing the ceramic rings, thereby shortening production cycles and lowering production costs.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A ceramic ring, characterized in that: include: A ceramic ring body (1) is provided with an annular narrow slit (3) on its outer surface, and the annular narrow slit (3) extends obliquely into the ceramic ring body (1) so that the inner wall of the annular narrow slit (3) forms a truncated cone side surface.

2. The ceramic ring according to claim 1, wherein: The shortest distance L1 between the opening of the annular narrow slit (3) and the axial end of the ceramic ring body (1) is 1-2 mm.

3. The ceramic ring according to claim 1, wherein: The shortest distance L2 between the groove bottom of the annular narrow slot (3) and the axial end of the ceramic ring body (1) is 1-1.5 mm.

4. The ceramic ring according to claim 1, wherein: The shortest distance L3 between the bottom of the annular narrow slot (3) and the inner wall of the ceramic ring body (1) is 1-1.5 mm.

5. The ceramic ring according to claim 1, wherein: The groove width L4 of the annular narrow slit (3) is 0.5-1.0 mm.

6. The ceramic ring according to claim 1, wherein: The groove wall surface of the annular narrow slot (3) close to the center line of the ceramic ring body (1) is a rough structure (2).

7. The ceramic ring according to claim 6, characterized in that The rough structure (2) comprises spiral protrusions spirally formed on the circumferential surface of the ceramic ring body (1).

8. The ceramic ring according to claim 7, wherein: The axial cross-section of the spiral protrusion is in the shape of a triangle, a rectangle, an arc or a trapezoid.

9. A graphite boat, characterized in that: A ceramic ring according to any one of claims 1 to 8 is provided.

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