Processing method for micron-level flatness of surface of ultrathin sic ring

Abstract

The application discloses a kind of processing methods of micron level flatness of ultra-thin SIC ring surface, to solve the stability of existing fixture in the process of clamping and processing SIC material, unable to realize the micron level flatness processing of deficiency.The present application comprises the following steps: S1, SIC ring is loaded into annealing furnace and annealed to release stress;S2, the SIC ring that completes annealing treatment is loaded to fixture, and a plurality of negative pressure adsorption holes are arranged on the circumference of the fixture, and the adsorption positioning of the SIC ring is realized by the negative pressure adsorption of the negative pressure adsorption hole;S3, polishing process forms micron level flatness, and a polishing disc is arranged below the SIC ring, and the polishing disc and the SIC ring are in contact and friction to grind and polish.The processing method of micron level flatness of ultra-thin SIC ring surface of the present application makes the clamping and processing process of ultra-thin SIC ring stable, not easy to deform, and ensures the machining precision requirement of micron level flatness of product.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically, to a method for fabricating an ultrathin SiC ring with micron-level flatness. Background Technology

[0002] In the semiconductor chip industry, semiconductor manufacturing equipment holds an extremely important strategic position. Precision ceramic components are core components of this equipment, playing a crucial role in vapor deposition and etching equipment. Currently, with the shrinking feature sizes of chips and the increasing energy of halogen plasmas, higher demands are being placed on the performance and precision of ceramics. For example, high-purity alumina (Al2O3) ceramic materials are no longer sufficient for electrostatic chucks used in silicon carbide wafer processing. Therefore, there is an urgent need to develop SiC (silicon carbide) precision ceramic products with stable chemical properties, high thermal conductivity, low coefficient of thermal expansion, and good wear resistance as replacements. Compared to alumina ceramics, SiC materials have better wear resistance, making them more difficult to process and resulting in higher production costs. Existing fixtures for clamping SiC materials exhibit poor stability during processing and cannot achieve micron-level flatness. Summary of the Invention

[0003] To overcome the above shortcomings, this invention provides a method for processing ultra-thin SiC rings with micron-level flatness. The ultra-thin SiC ring clamping and processing process has good stability and is not easily deformed, thus ensuring the processing accuracy requirements of micron-level flatness of the product.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for processing an ultrathin SiC ring surface with micron-level flatness, comprising the following steps:

[0005] S1. The SiC ring is placed in the annealing furnace for annealing treatment to release stress.

[0006] S2, The annealed SiC ring is loaded onto the fixture. The fixture is provided with several negative pressure adsorption holes spaced circumferentially. The SiC ring is adsorbed and positioned by the negative pressure adsorption of the negative pressure adsorption holes.

[0007] S3, polishing process to form micron-level flatness, a polishing disk is set below the SiC ring, the polishing disk and the SiC ring contact friction to perform grinding and polishing.

[0008] Annealing the SiC ring releases stress, reducing deformation during processing and improving machining accuracy. Vacuum adsorption technology is used to position the SiC ring, ensuring a sealed fit between the ring's upper surface and the fixture surface. This effectively reduces the likelihood of deformation during processing, further enhancing accuracy. Polishing is achieved through contact grinding with a polishing pad, resulting in micron-level flatness on the SiC ring surface.

[0009] The processing method for achieving micron-level flatness on the surface of ultrathin SiC rings in this patent application ensures good stability and resistance to deformation during the clamping and processing of ultrathin SiC rings, thereby guaranteeing the micron-level flatness processing accuracy requirements of the product.

[0010] Preferably, annealing pads are installed inside the annealing furnace, and SiC rings are mounted on the annealing pads for annealing.

[0011] During the annealing process, the annealing gaskets provide support for the SiC rings and prevent them from twisting and deforming.

[0012] Preferably, during the S3 process, polishing liquid is poured onto the polishing pad, and the polishing liquid and the polishing pad work together to polish the surface of the SiC ring.

[0013] The polishing fluid acts as a lubricant and coolant, and also prevents dust, thus improving the polishing effect.

[0014] Preferably, a negative pressure chamber is provided inside the fixture, and an air pipe connector is installed at the middle position on the upper surface of the fixture. Both the air pipe connector and the negative pressure adsorption hole are connected to the negative pressure chamber.

[0015] A vacuum pump is connected via a duct connector to generate negative pressure in the negative pressure chamber, thereby achieving reliable positioning of the SiC ring.

[0016] Preferably, the fixture includes an upper suction cup and a lower suction cup, with a negative pressure suction hole located on the lower suction cup and an air tube connector installed on the upper suction cup.

[0017] The fixture, formed by connecting the upper and lower suction cups, is easy to process.

[0018] As a preferred option, several weight-reducing holes are evenly distributed on the upper suction cup.

[0019] Weight reduction holes can reduce the weight of the fixture. During the grinding and polishing process, the SiC ring is subjected to the weight of the fixture. If the fixture is too heavy, the SiC ring will be damaged due to excessive weight.

[0020] Preferably, an annular groove and a central groove are provided on the lower surface of the upper suction cup, and several radial grooves are provided between the annular groove and the central groove on the lower surface of the upper suction cup. The negative pressure adsorption hole is provided in correspondence with the annular groove, and the air pipe connector is provided in correspondence with the central groove. A negative pressure cavity is formed between the annular groove, the central groove, the radial grooves and the lower suction cup.

[0021] During operation, vacuum adsorption is performed on various positions of the ring groove through several radial grooves, so that the adsorption of the SIC ring by the negative pressure adsorption holes at each position is more balanced, ensuring the reliable positioning of the SIC ring.

[0022] Preferably, the lower suction cup is made of alumina ceramic material, and the flatness of the lower surface of the lower suction cup is 2-4 micrometers.

[0023] The alumina ceramic material will not cause metal contamination to the SiC ring. The lower suction cup has a flat surface, ensuring a good seal with the SiC ring and guaranteeing effective negative pressure adsorption and positioning.

[0024] Preferably, the tracheal connector is a rotary connector, a positioning ring is set on the polishing disc, the fixture is placed in the positioning ring, and several positioning rollers are set above the polishing disc, with the outer wall of the positioning ring abutting against the positioning rollers; during S3, the polishing disc rotates, causing the positioning ring and fixture supported on the polishing disc to rotate together.

[0025] During operation, the polishing disc rotates, while the positioning ring and fixture are supported on it. Positioning rollers position the positioning ring, which in turn positions the fixture. As the polishing disc rotates, the outer wall of the positioning ring comes into contact with the positioning rollers. With continued rotation of the polishing disc, the positioning ring rotates in place, while the fixture is confined within the positioning ring. This movement within the positioning ring's range causes the SiC ring and the polishing disc to come into contact and rub against each other, achieving grinding and polishing. This method allows all areas of the polishing disc surface to participate in grinding, resulting in high utilization of the polishing surface. Furthermore, the rotation of both the polishing disc and the SiC ring reduces frictional resistance and improves machining accuracy. The rotation of both the polishing disc and the SiC ring allows for arbitrary and multiple directions of grinding and polishing on the SiC ring surface, further enhancing machining precision.

[0026] Preferably, several buffer blocks are installed at intervals on the inner wall of the positioning ring, a buffer spring is installed between the buffer blocks and the positioning ring, and a gap is provided between the buffer blocks and the outer wall of the fixture.

[0027] The rotation of the positioning ring and fixture causes an eccentricity, resulting in the outer wall of the fixture and the inner wall of the positioning ring moving closer and further apart. During this process, the outer wall of the fixture contacts the buffer block, which absorbs energy and prevents excessive impact force from damaging the SiC ring or causing it to detach from the fixture. The contact between the fixture and the buffer block causes the fixture to oscillate smoothly within a small range. This oscillation continuously changes the direction of the frictional force between the lower surface of the SiC ring and the polishing disc, allowing the lower surface of the SiC ring to be polished from various directions, thereby improving the polishing accuracy.

[0028] Compared with the prior art, the beneficial effects of the present invention are: (1) The processing method for achieving micron-level flatness of the ultrathin SiC ring surface in this patent application makes the ultrathin SiC ring clamping and processing process stable and not easily deformed, thus ensuring the processing accuracy requirements of micron-level flatness of the product; (2) After annealing the SiC ring, stress is released before grinding and polishing, which can reduce the deformation amplitude during processing and improve processing accuracy; (3) The negative pressure adsorption holes have a balanced adsorption force on each position of the SiC ring surface, ensuring reliable positioning of the SiC ring; (4) During operation, both the polishing disc and the SiC ring rotate, which can make each position of the polishing disc surface... The position participates in grinding, the grinding surface of the polishing disc has a high utilization rate, and it can reduce frictional resistance and improve processing accuracy; the grinding and polishing direction of the SIC ring surface is arbitrary and multiple, which is conducive to improving processing accuracy; (5) The buffer block installed in the positioning ring can absorb energy and avoid excessive impact force from damaging the SIC ring or causing the SIC ring to detach from the fixture; the fixture touches the buffer block, so that the fixture can shake smoothly in a small range. Through shaking, the direction of frictional force between the lower surface of the SIC ring and the polishing disc is constantly changed, so that the lower surface of the SIC ring can be rubbed and polished from all directions, thereby improving the polishing accuracy. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the fixture of the present invention;

[0030] Figure 2 This is an exploded view of the fixture of the present invention;

[0031] Figure 3 This is a schematic diagram of the SiC ring grinding and polishing structure of the present invention;

[0032] In the diagram: 1. SiC ring, 2. Fixture, 3. Negative pressure suction hole, 4. Air pipe connector, 5. Polishing disc, 6. Upper suction cup, 7. Lower suction cup, 8. Weight reduction hole, 9. Ring groove, 10. Central groove, 11. Radial groove, 12. Positioning ring, 13. Positioning roller, 14. Buffer block, 15. Buffer spring. Detailed Implementation

[0033] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0034] Example: A method for fabricating micron-level flatness on the surface of an ultrathin SiC ring (see appendix) Figure 1 To be continued Figure 3 ), including the following steps:

[0035] S1. The SiC ring is placed in the annealing furnace for annealing treatment to release stress; annealing gaskets are installed in the annealing furnace, and the SiC ring is mounted on the annealing gaskets for annealing; after the stress of the SiC ring is released by annealing, the deformation during the processing is reduced.

[0036] S2, the annealed SIC ring 1 is loaded onto the fixture 2. The fixture is provided with several negative pressure adsorption holes 3 at intervals around the circumference. There are two circles of negative pressure adsorption holes, which are staggered around the circumference. The negative pressure adsorption of the negative pressure adsorption holes is used to adsorb and position the SIC ring. A negative pressure cavity is provided inside the fixture. An air pipe connector 4 is installed in the middle position on the upper surface of the fixture. The air pipe connector and the negative pressure adsorption holes are connected to the negative pressure cavity.

[0037] S3, polishing process to form micron-level flatness, a polishing disk 5 is set below the SIC ring, the polishing disk and the SIC ring are contacted and rubbed to perform grinding and polishing; polishing liquid is poured on the polishing disk, the polishing liquid and the polishing disk work together to polish the surface of the SIC ring.

[0038] The fixture includes an upper suction cup 6 and a lower suction cup 7. Negative pressure suction holes are located on the lower suction cup, and the endotracheal connector is mounted on the upper suction cup. Several weight-reducing holes 8 are evenly distributed on the upper suction cup. An annular groove 9 and a central groove 10 are formed on the lower surface of the upper suction cup. Several radial grooves 11 are formed between the annular groove and the central groove on the lower surface of the upper suction cup. A radial groove is formed between two adjacent weight-reducing holes. The negative pressure suction holes and annular grooves are correspondingly arranged, and the endotracheal connector and central groove are correspondingly arranged. The lower surfaces of the upper and lower suction cups are bonded together, and a negative pressure cavity is formed between the annular groove, central groove, radial grooves, and the lower suction cup. The upper suction cup is made of aluminum, and the lower suction cup is made of alumina ceramic. The flatness of the lower surface of the lower suction cup is 2-4 micrometers.

[0039] The endotracheal connector is a rotary connector. A positioning ring 12 is set on the polishing disc, and a fixture is placed in the positioning ring. Several positioning rollers 13 are set above the polishing disc, and the outer wall of the positioning ring abuts against the positioning rollers. Several buffer blocks 14 are installed at intervals on the inner wall of the positioning ring, and buffer springs 15 are installed between the buffer blocks and the positioning ring. There is a gap between the buffer blocks and the outer wall of the fixture. The inner wall of the buffer blocks has an arc-shaped structure. The positioning ring and the fixture are both eccentrically set with respect to the polishing disc. During process S3, the polishing disc rotates, causing the positioning ring and fixture supported on the polishing disc to rotate together.

[0040] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications may be made without departing from the technical solutions described in the claims.

Claims

1. A processing method for the surface micrometer order flatness of an ultrathin SIC ring, characterized by, Includes the following steps: S1. The SiC ring is placed in the annealing furnace for annealing treatment to release stress. S2, The annealed SiC ring is loaded onto the fixture. The fixture is provided with several negative pressure adsorption holes spaced circumferentially. The SiC ring is adsorbed and positioned by the negative pressure adsorption of the negative pressure adsorption holes. S3, polishing process to form micron-level flatness, a polishing disk is set under the SiC ring, and the polishing disk and the SiC ring are contacted and rubbed to perform grinding and polishing; A positioning ring is set on the polishing disc, and the fixture is placed in the positioning ring. Several positioning rollers are set above the polishing disc, and the outer wall of the positioning ring abuts against the positioning rollers. During S3, the polishing disc rotates, which drives the positioning ring and fixture supported on the polishing disc to rotate together. Several buffer blocks are installed at intervals on the inner wall of the positioning ring, and buffer springs are installed between the buffer blocks and the positioning ring. There is a gap between the buffer blocks and the outer wall of the fixture.

2. The method for processing an ultrathin SiC ring with micron-level flatness according to claim 1, characterized in that, Annealing gaskets are installed inside the annealing furnace, and SiC rings are mounted on the annealing gaskets for annealing.

3. The method for processing an ultrathin SiC ring with micron-level flatness according to claim 1, characterized in that, During the S3 process, polishing fluid is poured onto the polishing pad, and the polishing fluid and polishing pad work together to polish the surface of the SiC ring.

4. A method for processing an ultrathin SiC ring with micron-level flatness according to claim 1, 2, or 3, characterized in that, The fixture has a negative pressure chamber inside, and an air pipe connector is installed in the middle of the upper surface of the fixture. The air pipe connector and the negative pressure adsorption hole are both connected to the negative pressure chamber.

5. The method for processing an ultrathin SiC ring with micron-level flatness according to claim 4, characterized in that, The fixture includes an upper suction cup and a lower suction cup. The negative pressure suction hole is located on the lower suction cup, and the air tube connector is installed on the upper suction cup.

6. The method for processing an ultrathin SiC ring with micron-level flatness according to claim 5, characterized in that, Several weight-reducing holes are evenly distributed on the upper suction cup.

7. The method for processing an ultrathin SiC ring with micron-level flatness according to claim 5, characterized in that, An annular groove and a central groove are provided on the lower surface of the upper suction cup. Several radial grooves are provided between the annular groove and the central groove on the lower surface of the upper suction cup. The negative pressure adsorption hole is provided in correspondence with the annular groove, and the air pipe connector is provided in correspondence with the central groove. A negative pressure cavity is formed between the annular groove, the central groove, the radial grooves and the lower suction cup.

8. The method for processing an ultrathin SiC ring with micron-level flatness according to claim 5, characterized in that, The lower suction cup is made of alumina ceramic, and the flatness of the lower surface of the lower suction cup is 2-4 micrometers.

9. A method for processing an ultrathin SiC ring with micron-level flatness according to claim 4, characterized in that, The endotracheal connector is a rotary connector.

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