HIP jig for high-purity alumina ceramic electrostatic chuck

Abstract

The invention discloses an HIP jig for a high-purity alumina ceramic electrostatic chuck, and belongs to the technical field of electrostatic chucks, the HIP jig comprises at least one woven structure jig body, the woven structure jig body comprises a plurality of transverse woven belts and a plurality of longitudinal woven belts woven together with the transverse woven belts, the transverse woven belts and the longitudinal woven belts are made of carbon fibers, a certain distance is arranged between any two adjacent transverse woven belts, and a certain distance is arranged between any two adjacent longitudinal woven belts. According to the technical scheme, by changing the form of the HIP jig, the contact area of the product and the jig is reduced, the gas passing rate between the product and the jig is increased, ceramic on the contact face of the product and the jig is more transparent, and the appearance and use performance of the electrostatic chuck are improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrostatic chucks, and in particular to a HIP jig for high-purity alumina ceramic electrostatic chucks. Background Art

[0002] As a key process equipment, electrostatic chuck is widely used in semiconductor manufacturing, optoelectronic industry and precision component processing. It uses electrostatic force to achieve non-destructive fixation and precise positioning of the workpiece, and therefore plays an important role in high-precision manufacturing. The core components of the electrostatic chuck are usually made of high-purity alumina ceramic material because of its excellent electrical insulation, mechanical strength and thermal stability. However, during the preparation process, how to further improve the transparency and performance of alumina ceramics is still one of the key issues in the current technical field.

[0003] HIP (Hot Isostatic Pressing) technology is widely used in the preparation of high-purity alumina ceramics because it can significantly improve the density and uniformity of ceramic materials. By treating ceramics under high temperature and high pressure, HIP technology can effectively eliminate tiny defects such as pores and cracks inside the material, and improve mechanical properties and electrical insulation. However, in the traditional HIP process, the electrostatic chuck ceramic is in direct contact with the fixture, resulting in the inability of gas to fully penetrate, especially in the contact surface area, which is prone to form opaque areas, affecting the transparency and performance of the ceramic material. Therefore, how to improve the gas transmittance and eliminate the local opacity of ceramics by improving the design of the HIP fixture has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a HIP jig for a high-purity alumina ceramic electrostatic chuck to solve the problem raised in the background technology.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A HIP jig for a high-purity alumina ceramic electrostatic chuck, the HIP jig comprising a woven structure jig body, the woven structure jig body comprising a plurality of transverse woven belts and a plurality of longitudinal woven belts woven together with the transverse woven belts, the transverse woven belts and the longitudinal woven belts are both made of carbon fiber, a certain distance is set between any two adjacent transverse woven belts, and a certain distance is set between any two adjacent longitudinal woven belts.

[0007] Preferably, the spacing between any two adjacent transverse braided belts is greater than or equal to the width of the transverse braided belt, and the spacing between any two adjacent longitudinal braided belts is greater than or equal to the width of the longitudinal braided belt.

[0008] Preferably, the width of the transverse braided belt is equal to that of the longitudinal braided belt.

[0009] Preferably, the spacing between any two adjacent transverse braided belts is equal to the spacing between any two adjacent longitudinal braided belts.

[0010] Preferably, the braided structure fixture body is a disc-shaped structure adapted to a disc-shaped electrostatic chuck HIP, and the diameter of the braided structure fixture body of the disc-shaped structure is 300-600 mm.

[0011] Preferably, the thickness of the braided structure fixture body is 3-5 mm, and the thickness of the braided structure fixture body is the distance between the highest surface and the lowest surface of the same transverse braided belt or the same longitudinal braided belt.

[0012] The above technical solution has the following beneficial effects:

[0013] The technical solution of the present application reduces the contact area between the product and the fixture and increases the gas permeability between the product and the fixture by changing the form of the HIP fixture, thereby making the ceramic on the contact surface between the product and the fixture more transparent and improving the appearance and performance of the electrostatic chuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the braided structure jig body of the present invention;

[0015] Figure 2 It is a structural schematic diagram of the small hole fixture body of the present invention. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] In response to the defects in the prior art, the present invention proposes a new HIP jig design, which optimizes the gas permeability so that the gas can more evenly penetrate the ceramic body, especially the contact area between the jig and the ceramic, to ensure that the density consistency and transparency of the ceramic material are significantly improved. The new jig design: By improving the jig structure, the gas can more evenly penetrate the ceramic surface, especially on the jig contact surface, avoiding the problem of local opacity caused by insufficient gas permeability. Improve ceramic transparency: The use of the new jig ensures that the ceramic material is more uniformly dense during the HIP treatment, thereby greatly improving the transparency of the alumina ceramic and improving the appearance and performance of the electrostatic suction cup. Uniform density and performance: Since the gas circulation is smoother, the new jig makes the density of each part of the ceramic body more uniform, reduces local performance differences, and enhances the overall mechanical strength and electrical insulation performance;

[0018] Through this improvement, the present invention effectively solves the problems of ceramic opacity and unstable performance caused by insufficient fixture design in the prior art, and significantly improves the overall performance and service life of the high-purity alumina electrostatic chuck;

[0019] Example 1

[0020] refer to Figure 1 A HIP fixture for a high-purity alumina ceramic electrostatic chuck, the HIP fixture comprises a braided structure fixture body 1, the braided structure fixture body 1 comprises a plurality of transverse braided belts 2 and a plurality of longitudinal braided belts 3 braided together with the transverse braided belts 2, the transverse braided belts 2 and the longitudinal braided belts 3 are both made of carbon fiber, which can withstand high temperatures and are convenient for use during high-temperature sintering of the ceramic disk without damage, and a certain distance is set between any two adjacent transverse braided belts 2, and a certain distance is set between any two adjacent longitudinal braided belts 3;

[0021] A plurality of transverse braided belts 2 and a plurality of longitudinal braided belts 3 are interwoven and woven together to form a whole. The weaving form can refer to the weaving form of textile fabrics, that is, a transverse braided belt 2 first passes under a longitudinal braided belt 3, and then passes over another longitudinal braided belt 3 adjacent thereto, and the above steps are repeated to complete the weaving of a transverse braided belt 2. Continuing to repeat can complete the weaving of all transverse braided belts 2, that is, the weaving of all transverse braided belts 2 and longitudinal braided belts 3 is completed. The transverse braided belts 2 and the longitudinal braided belts 3 can have the same shape, both of which are flat long strip structures, which are convenient for use after manufacturing and also convenient for weaving;

[0022] The spacing between any two adjacent transverse braided belts 2 is greater than or equal to the width of the transverse braided belt 2, and the spacing between any two adjacent longitudinal braided belts 3 is greater than or equal to the width of the longitudinal braided belt 3; there is a certain spacing between the transverse braided belts 2 to facilitate gas flow, and there is also a certain spacing between the longitudinal braided belts 3, which is combined with the braiding form to facilitate gas circulation;

[0023] In other implementations of this embodiment, the widths of the transverse braided belts 2 and the longitudinal braided belts 3 are equal, and the spacing between any two adjacent transverse braided belts 2 is equal to the spacing between any two adjacent longitudinal braided belts 3;

[0024] The braided structure fixture body 1 is a disc-shaped structure, which is suitable for the use of disc-shaped ceramic discs. The diameter of the braided structure fixture body 1 is 300-600 mm, which is selected according to the usage scenario and the size of the ceramic disc to be sintered. The thickness of the braided structure fixture body 1 is 3-5 mm. The overall thickness after weaving will not be completely consistent, and the thickness of each part can be within the range of 3-5 mm. The thickness of the braided structure fixture body is the distance between the highest surface and the lowest surface of the same transverse braided belt 2 or the same longitudinal braided belt 3. It has a certain thickness, which is convenient for supporting the ceramic disc to be sintered;

[0025] The technical solution of the present application reduces the contact area between the product and the fixture by changing the form of the HIP fixture, and increases the gas permeability between the product and the fixture, thereby making the ceramic on the contact surface between the product and the fixture more transparent, and improving the appearance and performance of the electrostatic chuck;

[0026] When using a fiber-woven fixture for HIP treatment, its unique woven structure provides a more optimized gas flow path for high-purity alumina ceramics. Compared with open-hole fixtures, it has unique advantages in improving the flatness, light transmittance and color consistency of ceramics. Its principle can be explained from the following aspects:

[0027] 1. Formation of gas circulation space

[0028] The surface of the fiber woven structure fixture has staggered fiber layers, and tiny gaps are naturally formed between these layers. These gaps can provide a uniform flow path for the gas. This means that the gas can flow more freely between the ceramic and the fixture, unlike the small holes in the solid fixture that rely on specific through-hole locations.

[0029] The uniform flow of gas helps to uniformly pressurize and densify the entire ceramic surface, effectively eliminating internal pores and tiny defects. This directly improves the light transmittance of the ceramic and makes the color more consistent, because the gas flow in different areas is uniform, and the density and microstructure of the material become more consistent;

[0030] 2. Reduce local pressure differences

[0031] The fiber-woven jig can transfer pressure to the ceramic body more evenly during HIP treatment, because the flexibility of the fiber weaving allows it to evenly adapt to the shape of the ceramic body. This feature avoids the problem of local pressure differences caused by improper aperture design or uneven opening of traditional solid jigs;

[0032] Uniform pressure transmission ensures that the ceramic is subjected to uniform force throughout the entire processing process, thereby reducing deformation or local stress concentration. This is important for maintaining the flatness and overall consistency of the ceramic;

[0033] 3. Reduce the formation of pores and microcracks

[0034] In HIP treatment, the flow of gas can promote the discharge of pores inside the ceramic and improve the density of the material. Fiber-woven jigs can provide a more continuous and uniform gas discharge path due to their complex fiber network structure. Compared with open-pored jigs, the fiber structure allows the gas to flow freely through the multi-dimensional paths of the fabric, not just the pores, thereby improving the densification effect of the ceramic material.

[0035] The increase in density helps to reduce the residual microcracks and pores, thereby improving the light transmittance of the ceramic, making it present a more consistent light transmittance effect under light, thereby improving the quality of the product;

[0036] 4. Color consistency

[0037] Since the fiber braided jig has more uniform gas flow and heat transfer, the sintering and densification process of alumina ceramics will be more stable, which helps to form a consistent microstructure throughout the surface and inside of the material;

[0038] This not only improves the light transmittance of the ceramic, but also makes the final product visually more consistent in color. For materials such as high-purity alumina ceramics that require high color consistency, the use of fiber braiding jigs can significantly reduce color differences caused by uneven pressurization or densification.

[0039] In the case of Example 1, the present application reduces the contact area between the product and the fixture while ensuring flatness, improves the transparency and uniformity of the product, and thus improves the consistency of the product's density, hardness, resistivity and light transmittance.

[0040] Example 2

[0041] refer to Figure 2The HIP jig further comprises at least one small hole jig body 4, which is arranged above or below the braided structure jig body 1, and is provided with a plurality of through holes 5 which pass through the small hole jig body 4 from top to bottom; the small hole jig body 4 is made of any one of graphite, molybdenum and tungsten, which are resistant to high temperatures and are convenient for high temperature sintering of ceramic discs;

[0042] The small hole fixture body 4 is a disc-shaped structure, and the diameter of the disc-shaped small hole fixture body 4 is 300-600 mm. The specific size is selected according to the use requirements, and the thickness is 20 mm or 50 mm, or 35 mm;

[0043] The flatness of the working surface of the small hole fixture body 4 is 50μm or 500μm, and in other implementations of the present embodiment, it can also be 250μm, and the roughness is 0.5μm or 5μm, and in other implementations of the present embodiment, it can also be 2.5μm; the diameter of the through hole is 10mm or 30mm, and in other implementations of the present embodiment, it can also be 20mm, and the spacing between adjacent through holes is 3mm or 5mm, and in other implementations of the present embodiment, it can also be 4mm.

[0044] Example 3

[0045] refer to Figure 2 The diameter of the through hole on the small hole fixture body 4 is 40 mm or 70 mm. In other implementations of this embodiment, the aperture is larger than the aperture in Example 2. As a comparative example, the ceramic disk sintered under the conditions in Example 2 is compared. The spacing between adjacent through holes is 6 mm or 9 mm. In other implementations of this embodiment, it can also be 8 mm. The small hole fixture body 4 is made of any one of graphite, molybdenum, and tungsten.

[0046] Example 4

[0047] The small hole jig body 4 is made of any one of graphite, molybdenum, and tungsten. The diameter of the through hole 5 is zero, that is, the small hole jig body 4 has no hole. During sintering, the ceramic disk is directly placed on the small hole jig body 4. Example 4 without a hole is used as a comparative example and compared with the above-mentioned Examples 1 to 3.

[0048] The results of the ceramic discs sintered in the above four embodiments are shown in Table 1 below:

[0049] Table 1:

[0050]

[0051] According to Table 1 above, the following conclusions can be drawn: Compared with traditional open-pored graphite jigs, fiber-woven jigs have more flexible and uniform gas flow paths, and can provide more uniform pressure and heat distribution during the HIP process, which makes the pores of the ceramics eliminated more thoroughly, and the surface density and uniformity are higher, thereby significantly improving the flatness, light transmittance and color consistency of the ceramics. The characteristics of the fiber-woven structure provide processing conditions for the manufacture of high-precision ceramic products that are superior to traditional jigs.

[0052] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A HIP fixture for high-purity alumina ceramic electrostatic chuck, characterized in that: The HIP fixture includes a woven structure fixture body, and the woven structure fixture body includes a plurality of transverse woven belts and a plurality of longitudinal woven belts woven together with the transverse woven belts. The transverse woven belts and the longitudinal woven belts are both made of carbon fiber. A certain distance is set between any two adjacent transverse woven belts, and a certain distance is set between any two adjacent longitudinal woven belts.

2. A HIP fixture for high-purity alumina ceramic electrostatic chuck according to claim 1, characterized in that: The spacing between any two adjacent transverse braided belts is greater than or equal to the width of the transverse braided belt, and the spacing between any two adjacent longitudinal braided belts is greater than or equal to the width of the longitudinal braided belt.

3. A HIP fixture for high-purity alumina ceramic electrostatic chuck according to claim 2, characterized in that: The widths of the transverse braided bands are equal to those of the longitudinal braided bands.

4. A HIP fixture for high-purity alumina ceramic electrostatic chuck according to claim 2, characterized in that: The spacing between any two adjacent transverse braided belts is equal to the spacing between any two adjacent longitudinal braided belts.

5. The HIP fixture for high-purity alumina ceramic electrostatic chuck according to claim 1, characterized in that: The braided structure fixture body is a disc-shaped structure adapted to a disc-shaped electrostatic chuck HIP, and the diameter of the disc-shaped braided structure fixture body is 300-600 mm.

6. The HIP fixture for high-purity alumina ceramic electrostatic chuck according to claim 1, characterized in that: The thickness of the braided structure fixture body is 3-5 mm, and the thickness of the braided structure fixture body is the distance between the highest surface and the lowest surface of the same transverse braided belt or the same longitudinal braided belt.

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