A new center press structure and single-side polishing equipment

Abstract

This utility model discloses a novel central pressurization structure and a single-sided polishing device. The novel central pressurization structure includes a pressurization outer cover with a downward opening, an airbag fixing ring threaded to the inner side of the pressurization outer cover, and an airbag diaphragm. An air pipe interface is provided through the center of the pressurization outer cover. The circumferential edge of the airbag diaphragm is clamped between the pressurization outer cover and the airbag fixing ring, forming an air cavity connecting the air pipe interface between the airbag diaphragm and the pressurization outer cover. A pressure plate is also axially slidably connected to the opening of the pressurization outer cover. The middle portion of the pressure plate is directly opposite the airbag diaphragm, and a ceramic disc is fixedly connected to the lower side of the pressure plate. This application effectively addresses the technical problem in existing single-sided polishing devices where edge effects exist on the polished wafer surface, resulting in poor surface flattening and affecting the yield of polished finished products.

Description

Technical Field

[0001] This application relates to the field of polishing technology, and in particular to a novel central pressure structure and single-sided polishing equipment. Background Technology

[0002] Chemical mechanical polishing (CMP) is a key process in integrated circuit manufacturing for achieving wafer surface planarization. It combines surface chemical action and mechanical abrasion to remove micron / nanoscale materials from the wafer surface, achieving nanoscale surface planarization and enabling subsequent photolithography processes. The main working principle of CMP is that under pressure and the action of a polishing slurry, the wafer being polished moves relative to the polishing pad. Through the combined mechanical and chemical action, the polished wafer surface achieves high planarization, low surface roughness, and low defects.

[0003] In single-sided polishing equipment, the main disk rotates while the main polishing head rotates eccentrically under pressure during product processing. Surface polishing is achieved through the mechanical grinding action of nano-abrasives and the chemical action of various chemical reagents. During CMP polishing, the polishing effect exhibits a CMP edge effect when the pressure is consistent, posing a potential challenge to the high planarity requirements of wafer surfaces and presenting certain limitations. Specifically: First, because the edge has a larger polishing area compared to other parts, the distribution of CMP liquid and abrasive in the edge region is uneven, leading to inconsistent CMP results. Second, the edge may have geometric or structural irregularities, such as sharp edges or steps, which also affect the polishing effect. Furthermore, the poorer contact between the edge and the CMP pad results in fewer abrasive particles in the edge region, further exacerbating the edge effect. Utility Model Content

[0004] This application provides a novel central pressure structure and a single-sided polishing device, which can improve the technical problem that when the single-sided polishing device in the prior art polishes, there is an edge effect on the surface of the polished wafer, resulting in poor surface flattening effect and affecting the pass rate of the polished product.

[0005] Firstly, this application provides a novel central pressurization structure, employing the following technical solution:

[0006] A novel central pressurization structure includes a pressurization outer cover with a downward opening, an airbag fixing ring threaded to the inner side of the pressurization outer cover, and an airbag diaphragm. The pressurization outer cover has a through-hole air tube interface. The circumferential edge of the airbag diaphragm is clamped between the pressurization outer cover and the airbag fixing ring, forming an air cavity between the airbag diaphragm and the pressurization outer cover that communicates with the air tube interface. A pressure plate is also axially slidably connected to the opening of the pressurization outer cover. The middle part of the pressure plate is directly opposite the airbag diaphragm, and a ceramic disc is fixedly connected to the lower side of the pressure plate.

[0007] Optionally, the pressurized outer cover includes a top plate and an inner ring fixedly connected to the lower side of the top plate at its upper end. The air pipe interface is opened through the center of the top plate, and the outer side of the airbag fixing ring is threadedly connected to the inner side of the inner ring.

[0008] Optionally, the pressure plate includes a base plate and a force-bearing plate, the force-bearing plate and the base plate are coaxially arranged, and the diameter of the force-bearing plate is smaller than the diameter of the base plate. The upper end of the force-bearing plate is directly opposite the airbag diaphragm, and the base plate is axially slidably connected to the pressurized outer cover.

[0009] Optionally, the outer side of the upper end of the force-bearing plate is fitted with the inner side of the inner ring with a gap, and the gap is no more than 3mm.

[0010] Optionally, the pressure cover has at least two stepped holes, each stepped hole being circumferentially distributed, and the pressure plate has multiple first internal threaded holes, each first internal threaded hole being directly opposite each stepped hole; the novel central pressure structure also includes multiple screws, the heads of each screw being slidably connected to each stepped hole, and the shanks being threadedly connected to the corresponding first internal threaded holes.

[0011] Optionally, each of the first internal threaded holes has a second internal threaded hole at its bottom, and each of the screws has a fastening hole that can connect to the corresponding second internal threaded hole. The connected second internal threaded hole and the fastening hole are simultaneously connected to fasteners.

[0012] Optionally, the pressure cover includes an outer ring whose upper end is fixedly connected to the lower side of the outer edge of the top plate; the novel central pressure structure also includes an outer fixing ring and a spring ring, the outer fixing ring is sleeved on the outside of the pressure plate and its upper end is threadedly connected to the lower end of the outer ring, the outer edge of the spring ring is clamped between the outer ring and the outer fixing ring, and the inner end of the spring ring is fixedly connected to the pressure plate.

[0013] Optionally, the novel central pressure structure further includes an inner fixing ring, the inner ring of which is threadedly connected to the pressure plate, and the inner end of the spring ring is clamped between the inner fixing ring and the pressure plate.

[0014] Optionally, when the spring coil is in its natural state, the ceramic disc extends downwards from the lower opening of the outer ring.

[0015] Secondly, this application provides a single-sided polishing device, including the novel central pressure structure described above.

[0016] In summary, this application includes the following beneficial technical effects:

[0017] The novel central pressurization structure of this application inflates the air chamber through the air pipe interface. After the gas is injected, the air bladder diaphragm deforms, pushing the pressure plate relative to the pressurization cover to move downwards toward the wafer being polished. This pressurizes the ceramic disk carrier, causing the pressure distribution on the surface of the ceramic disk carrier to tend to be larger in the middle and smaller at the outer edge. This makes the polishing amount of the outer and inner edges tend to be balanced, thus improving the technical problem of edge effect on the surface of the wafer being polished in the existing single-sided polishing equipment, which leads to poor surface flattening effect and affects the qualification rate of polished products. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the novel central pressurization structure of this application.

[0019] Figure 2 This is a cross-sectional view of the novel centrally pressurized structure of this application.

[0020] Figure 3 yes Figure 2 An enlarged view of the left side of the structure.

[0021] Explanation of reference numerals in the attached drawings: 1. Pressurized outer cover; 11. Top plate; 111. Air tube interface; 112. Stepped hole; 12. Inner ring; 13. Outer ring; 2. Airbag fixing ring; 3. Airbag diaphragm; 31. Air chamber; 4. Pressure plate; 41. Base plate; 42. Force plate; 43. Sliding ring; 431. First internal threaded hole; 432. Second internal threaded hole; 5. Ceramic disc; 6. Screw; 61. Fastening hole; 7. Outer fixing ring; 8. Spring ring; 9. Inner fixing ring. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0023] This application discloses a novel centrally pressurized structure.

[0024] Reference Figures 1 to 3A novel central pressurization structure includes a pressurization outer cover 1 with a downward opening, an airbag fixing ring 2 with its outer side threaded to the inner side of the pressurization outer cover 1, and an airbag diaphragm 3. The pressurization outer cover 1 has a through-hole air tube interface 111. The circumferential edge of the airbag diaphragm 3 is clamped between the pressurization outer cover 1 and the airbag fixing ring 2, so that an air cavity 31 communicating with the air tube interface 111 is formed between the airbag diaphragm 3 and the pressurization outer cover 1. A pressure plate 4 is also axially slidably connected to the opening of the pressurization outer cover 1. The middle part of the pressure plate 4 is directly opposite to the airbag diaphragm 3, and a ceramic disc 5 is fixedly connected to the lower side of the pressure plate 4.

[0025] During operation, the air source inflates the air chamber 31 through the air pipe interface 111. After the gas is injected, the air bladder diaphragm 3 deforms, pushing the pressure plate 4 relative to the pressure cover 1 to move downward toward the wafer being polished. This pressurizes the ceramic disk 5 carrier, causing the pressure distribution on the surface of the ceramic disk 5 carrier to tend to be larger in the middle and smaller at the outer edge. This balances the polishing amount between the outer and inner edges, improving the technical problem of edge effect on the surface of the wafer being polished in existing single-sided polishing equipment, which leads to poor surface flattening and affects the yield of polished finished products.

[0026] The pressurized outer cover 1 includes a top plate 11 and an inner ring 12 fixedly connected to the lower side of the top plate 11 at its upper end. An air pipe interface 111 is opened through the center of the top plate 11, and the outer side of the airbag fixing ring 2 is threadedly connected to the inner side of the inner ring 12. The inner ring 12 is used to achieve stable installation of the airbag fixing ring 2, ensuring a stable clamping effect on the circumferential edge of the airbag diaphragm 3.

[0027] The pressure cover 1 also includes an outer ring 13 that is fixedly connected to the lower side of the outer edge of the top plate 11. The inner diameter of the outer ring 13 is larger than the outer diameter of the inner ring 12.

[0028] The pressure plate 4 includes a base plate 41 and a force-bearing plate 42, which are coaxially arranged. The diameter of the force-bearing plate 42 is smaller than that of the base plate 41. The upper end of the force-bearing plate 42 is directly opposite the airbag diaphragm 3. The base plate 41 is axially slidably connected to the pressurized outer cover 1. The extension of the force-bearing plate 42 towards the airbag diaphragm 3 allows the deformed airbag diaphragm 3 to exert an effective compressive force on the pressure plate 4 through the force-bearing plate 42, causing the pressure distribution on the surface of the ceramic disc 5 carrier to tend to be the largest in the middle.

[0029] The pressure plate 4 also includes a sliding ring 43 with an inner diameter larger than that of the force plate 42. The lower end of the sliding ring 43 is fixedly connected to the upper side of the base plate 41, and the upper end extends toward the base plate 41.

[0030] The outer upper end of the force-bearing plate 42 is fitted with the inner side of the inner ring 12 with a gap of no more than 3mm. This reduces the possibility of the deformed airbag diaphragm 3 entering the gap between the force-bearing plate 42 and the inner ring 12, allowing the deformed airbag diaphragm 3 to effectively compress the pressure plate 4 through the force-bearing plate 42.

[0031] Reference Figure 2 and Figure 3 The top plate 11 of the pressure cover 1 has at least two stepped holes 112 through it. The stepped holes 112 are evenly distributed around the periphery. The sliding ring 43 of the pressure plate 4 has multiple first internal thread holes 431, and each first internal thread hole 431 is directly opposite to each stepped hole 112. The new central pressure structure also includes multiple screws 6. The head of each screw 6 is slidably connected to each stepped hole 112, and the rod is threadedly connected to the corresponding first internal thread hole 431.

[0032] The pressure plate 4 is stably connected to the pressure cover 1 by the connection of each screw 6. When the airbag diaphragm 3 deforms and squeezes the pressure plate 4, the pressure plate 4 under force causes the screw 6 to slide relative to the pressure cover 1, so that the pressure distribution on the surface of the ceramic disc 5 carrier tends to be larger in the middle, until the head of the screw 6 abuts against the shoulder of the stepped hole 112, at which point the pressure reaches its maximum.

[0033] Of course, before the airbag diaphragm 3 deforms and squeezes the pressure plate 4, the ceramic disk 5 abuts against the polished wafer, and there is a gap between the head of the screw 6 and the shoulder of the stepped hole 112.

[0034] Specifically, the number of stepped holes 112, first internal threaded holes 431, and screws 6 can be two, three, four, or five, etc.

[0035] Each first internal threaded hole 431 has a second internal threaded hole 432 at its bottom, and each screw 6 has a fastening hole 61 that can connect to the corresponding second internal threaded hole 432. The connected second internal threaded hole 432 and fastening hole 61 are connected to fasteners.

[0036] The connection between screw 6 and pressure plate 4 is strengthened by using fasteners to prevent screw 6 from loosening.

[0037] Reference Figure 2 and Figure 3 The new central pressure structure also includes an outer fixing ring 7 and a spring ring 8. The outer fixing ring 7 is sleeved on the outside of the pressure plate 4, and its upper end is threaded to the lower end of the outer ring 13. The outer edge of the spring ring 8 is clamped between the outer ring 13 and the outer fixing ring 7, and the inner end of the spring ring 8 is fixedly connected to the pressure plate 4.

[0038] When the airbag diaphragm 3 deforms, it creates pressure on the pressure plate 4, causing the pressure plate 4 to slide downwards away from the pressurized outer cover 1. The spring coil 8 undergoes adaptive deformation. When the gas in the air chamber 31 is discharged, the pressure plate 4 can slide back to its original position under the action of the spring coil 8, which restores its original shape.

[0039] Among them, the spring coil 8 can be made of spring steel.

[0040] The new central pressure structure also includes an inner fixing ring 9, the inner ring of which is threaded to the outside of the sliding ring 43 of the pressure plate 4, and the inner end of the spring ring 8 is clamped between the inner fixing ring 9 and the pressure plate 4.

[0041] The spring ring 8 is stably installed by the clamping action of the outer ring 13 and the outer fixing ring 7, and the combined clamping action of the inner fixing ring 9 and the pressure plate 4, ensuring that the pressure plate 4 and the ceramic disc 5 can return to their original positions under the action of the spring ring 8.

[0042] Furthermore, when the spring ring 8 is in its natural state, the ceramic disc 5 extends downwards from the lower opening of the outer ring 13 to ensure that the ceramic disc 5 can be polished without applying central pressure.

[0043] This application also discloses a single-sided polishing device, including the novel central pressure structure described above.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A novel centrally pressurized structure, characterized in that: The device includes a pressurized outer cover (1) with a downward opening, an airbag fixing ring (2) with an outer thread connected to the inner side of the pressurized outer cover (1), and an airbag diaphragm (3). The pressurized outer cover (1) has a through air tube interface (111) in the center. The circumferential edge of the airbag diaphragm (3) is clamped between the pressurized outer cover (1) and the airbag fixing ring (2), so that an air cavity (31) is formed between the airbag diaphragm (3) and the pressurized outer cover (1) that communicates with the air tube interface (111). A pressure plate (4) is also axially slidably connected to the opening of the pressurized outer cover (1). The middle part of the pressure plate (4) is directly opposite to the airbag diaphragm (3), and a ceramic disc (5) is fixedly connected to the lower side of the pressure plate (4).

2. The novel central pressurization structure according to claim 1, characterized in that: The pressurized outer cover (1) includes a top plate (11) and an inner ring (12) fixedly connected to the lower side of the top plate (11) at the upper end. The air pipe interface (111) is opened through the center of the top plate (11), and the outer side of the airbag fixing ring (2) is threadedly connected to the inner side of the inner ring (12).

3. The novel central pressurization structure according to claim 2, characterized in that: The pressure plate (4) includes a base plate (41) and a force plate (42). The force plate (42) and the base plate (41) are coaxially arranged, and the diameter of the force plate (42) is smaller than the diameter of the base plate (41). The upper end of the force plate (42) is directly opposite to the airbag diaphragm (3). The base plate (41) is axially slidably connected to the pressurized outer cover (1).

4. The novel central pressurization structure according to claim 3, characterized in that: The outer side of the upper end of the force plate (42) is fitted with the inner side of the inner ring (12) with a gap of no more than 3mm.

5. The novel central pressurization structure according to claim 1, characterized in that: The pressure cover (1) has at least two stepped holes (112) through it, and each stepped hole (112) is evenly distributed around the periphery. The pressure plate (4) has multiple first internal thread holes (431), and each first internal thread hole (431) is directly opposite to each stepped hole (112). The novel central pressure structure also includes multiple screws (6), the head of each screw (6) is slidably connected to each stepped hole (112), and the rod is threadedly connected to the corresponding first internal thread hole (431).

6. The novel central pressurization structure according to claim 5, characterized in that: Each of the first internal threaded holes (431) has a second internal threaded hole (432) at the bottom, and each of the screws (6) has a fastening hole (61) that can connect to the corresponding second internal threaded hole (432). The connected second internal threaded hole (432) and the fastening hole (61) are connected to fasteners.

7. The novel central pressurization structure according to claim 2, characterized in that: The pressure cover (1) includes an outer ring (13) whose upper end is fixedly connected to the lower side of the outer edge of the top plate (11); the novel central pressure structure also includes an outer fixing ring (7) and a spring ring (8). The outer fixing ring (7) is sleeved on the outside of the pressure plate (4) and its upper end is threaded to the lower end of the outer ring (13). The outer edge of the spring ring (8) is clamped between the outer ring (13) and the outer fixing ring (7), and the inner end of the spring ring (8) is fixedly connected to the pressure plate (4).

8. The novel central pressurization structure according to claim 7, characterized in that: The novel central pressure structure also includes an inner fixing ring (9), the inner ring of which is threadedly connected to the pressure plate (4), and the inner end of the spring ring (8) is clamped between the inner fixing ring (9) and the pressure plate (4).

9. The novel central pressurization structure according to claim 7, characterized in that: When the spring coil (8) is in its natural state, the ceramic disc (5) extends downwards from the lower opening of the outer ring (13).

10. A single-sided polishing device, characterized in that: Including the novel central pressurization structure as described in any one of claims 1-9.

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