Improved structure of chemical mechanical grinding head

Abstract

The utility model relates to an improved structure of a chemical mechanical grinding head. The improved structure mainly comprises a gas shunting seat, a balance ring frame and the gas shunting seat form an airtight cavity; and an elastic diaphragm is arranged on the side wall of the balancing ring frame to elastically transfer pressure. A membrane fixing ring is located below the balancing ring frame, a plurality of grooves are formed in the surface of the membrane fixing ring in a concentric circle mode, sucker-shaped grooves are formed in each groove at intervals, an annular bead chain type adsorption structure is formed, the functions of air suction adsorption and positive pressure release are supported, and pressure can be independently adjusted in a partitioned mode. Wherein the balancing ring frame is a disc with a center shaft, and a triangular cone-shaped reinforcing wall is arranged at the bottom of the balancing ring frame; the carrier of the grinding head can be made of aluminum alloy or stainless steel materials, weight balance is achieved through the hollowed-out design and the reinforcing structure, and the practical structure which has strength and light weight and is suitable for the advanced CMP process is achieved.

Description

Improved Structure of Chemical Mechanical Grinding Head Technical Field

[0001] This utility model relates to the technical field of chemical mechanical grinding instruments, and more particularly to an improved structure of a chemical mechanical grinding head. Background Technology

[0002] Traditional chemical mechanical polishing (CMP) equipment used in semiconductor processes primarily functions to achieve high-precision planarization of the wafer surface through a polishing process, facilitating subsequent circuit layer deposition and etching. While existing CMP polishing heads possess basic polishing capabilities, they still suffer from the following major drawbacks:

[0003] Existing CMP polishing heads typically employ a concentric arrangement of pores in their wafer adsorption structure, concentrating adsorption force in specific areas. This can easily lead to unstable adsorption or wafer misalignment, affecting polishing accuracy and safety. Especially with the increasing size of wafers (e.g., 12 inches and above), or applications in ultra-thin wafers and back-side polishing processes, current adsorption mechanisms are prone to uneven adsorption distribution. This uneven adsorption can cause wafer bonding surface warping or localized suspension, leading to center dishing, edge roll-off, or even wafer breakage during polishing. Furthermore, if adsorption is concentrated in the central area, insufficient force at the edges can easily cause wafer slippage or detachment during high-speed rotation, affecting process stability and increasing yield risks.

[0004] In addition, the main body of existing CMP grinding heads is usually made of aluminum alloy. While this structure is easier to form and drive, the spindle is prone to stress concentration under high-speed rotation and pressure, leading to cracking at the L-shaped corner beneath the spindle. This spindle is often subjected to combined forces from the motor and pneumatic system during pressurization and rotation, making it highly susceptible to fatigue stress concentration and cracking. Past cases have shown spindle breakage or eccentricity issues in high-speed or high-pressure processes, further resulting in uneven grinding or even complete machine failure. Summary of the Invention

[0005] In view of this, the main objective of this utility model is to provide an improved structure for a chemical mechanical grinding head, mainly comprising at least a gas splitter, a balance ring frame, an elastic diaphragm, a fixing ring, and a diaphragm fixing ring, wherein...

[0006] A gas distributor is located above the center of an annular vehicle and has at least one gas flow channel for accessing control gas pressure.

[0007] The balance ring frame is fitted in the carrier and forms an airtight cavity with the gas diversion seat, and the side ring is equipped with a diaphragm seat;

[0008] An elastic diaphragm is disposed on the diaphragm seat and is used to transmit pressure through elastic expansion and contraction;

[0009] A retaining ring, located below the carrier, is framed around the membrane retaining ring, and:

[0010] The membrane fixing ring, located below the balance ring frame, has multiple concentric grooves on its surface that are connected to the air pressure control. Each groove is provided with a circular suction cup-shaped groove, forming a ring-shaped bead chain arrangement. The suction cup-shaped grooves can adsorb the wafer in suction mode and release the wafer in positive pressure mode, and support independent pressure adjustment in each zone.

[0011] In a preferred embodiment, the balance ring frame is a disc with a central axis, and the outer diaphragm seat is a multi-layered, outwardly expanding stepped disc. The bottom of the disc is integrally connected to the bottom of the central axis to form a triangular pyramid-shaped reinforcing wall.

[0012] In a preferred embodiment, the balance ring frame is made of aluminum alloy or stainless steel, and the carrier is also made of aluminum alloy or stainless steel. Multiple perforations are spaced apart on its annular surface to reduce weight and achieve weight balance with the reinforced balance ring frame.

[0013] In a preferred embodiment, a plurality of perforated spacers are arranged in a groove on the carrier.

[0014] In a preferred embodiment, the concentric grooves on the surface of the membrane fixing ring are arranged in two layers, an inner and an outer layer, and the circular suction cup-shaped grooves on the outer and inner grooves are arranged alternately and at intervals.

[0015] In a preferred embodiment, the circular suction cup-shaped grooves on the inner and outer grooves arranged in concentric circles are further distributed in a triangular grid pattern by having two short inclined grooves connected to each other in a pair.

[0016] Compared with existing technologies, this invention has the following advantages: The film fixing ring includes multiple circular suction cup-shaped grooves forming a beaded chain, which can be further arranged in a radial triangular grid pattern to achieve multi-point distributed vacuum adsorption and positive pressure release, as well as pressure zone control according to a zone-by-zone strategy, improving wafer bonding uniformity and polishing stability. This gives the overall structure advantages such as stable adsorption, lightweight and high strength, and precise pressure division, improving wafer bonding uniformity and polishing stability, making it more suitable for next-generation semiconductor wafer planarization processes. Attached Figure Description

[0017] Figure 1 is a cross-sectional view of the assembled chemical mechanical grinding head of this utility model;

[0018] Figure 2 is a plan view of the first embodiment of the membrane fixing ring of this utility model;

[0019] Figure 3 is a plan view of the second embodiment of the membrane fixing ring of this utility model;

[0020] Figure 4 is a perspective view of the second embodiment of the membrane fixing ring of this utility model;

[0021] Figure 5 is a partial exploded perspective view of the chemical mechanical grinding head of this utility model;

[0022] Figure 6 is a cross-sectional view of the balance ring frame of this utility model.

[0023] In the diagram: 1. Gas splitter seat; 10. Carrier; 101. Hole; 110. Groove; 15. Gas flow channel; 2. Balance ring frame; 20. Airtight cavity; 21. Central shaft; 22. Diaphragm seat; 23. Disc; 25. Reinforcing wall; 3. Elastic diaphragm; 4. Fixing ring; 5. Diaphragm fixing ring; 50. Groove; 51. Groove; 510. Short inclined groove. Detailed Implementation

[0024] To facilitate understanding of the content and effects of this utility model, specific embodiments are listed below with reference to the accompanying drawings, and detailed descriptions are provided below: Referring to Figures 1 to 4, the improved structure of a chemical mechanical grinding head provided by this utility model mainly includes: at least one gas distribution seat 1, one balance ring frame 2, one elastic diaphragm 3, one fixing ring 4, and one diaphragm fixing ring 5, wherein...

[0025] A gas splitter 1 is disposed above the center of an annular carrier 10 and has at least one gas flow channel 15 for accessing control gas pressure.

[0026] The balance ring 2 is sleeved in the middle of the carrier 10 and forms an airtight cavity 20 with the gas diversion seat 1, and the side ring is provided with a diaphragm seat 22.

[0027] An elastic diaphragm 3 is disposed on a diaphragm seat 22 and is used to transmit pressure through elastic expansion and contraction.

[0028] The fixing ring 4 is located below the carrier 10, and frames the periphery of the membrane fixing ring 5, and:

[0029] The membrane fixing ring 5 is located below the balance ring frame 2. Its surface has multiple concentric grooves 51 that are connected to the air pressure control. Each groove 51 is provided with a circular suction cup-shaped groove 50, forming a ring-shaped bead chain arrangement. The suction cup-shaped groove 50 can adsorb the wafer in the suction mode and release the wafer in the positive pressure mode, and supports independent pressure adjustment in each zone.

[0030] In a preferred embodiment, as shown in Figure 2, the concentric circular grooves 51 on the surface of the membrane fixing ring 5 are further configured as inner and outer channels, and the circular suction cup-shaped grooves 50 on the outer channel groove 51 and the inner channel groove 51 are arranged alternately. Therefore, in application, the surface of the membrane fixing ring 5 is provided with multiple rows of equidistant circular adsorption grooves 50, which are arranged like a string of suction cups to form a beaded distribution, increasing the adsorption area and stability. It can provide uniform multi-point adsorption for different areas of the wafer, simulating a near-planar suction force distribution, effectively improving the wafer bonding stability and reducing the risk of wafer breakage.

[0031] A preferred embodiment, as shown in Figures 3 and 4, involves circular suction cup-shaped grooves 50 on both the outer and inner channel grooves 51. These grooves are further interconnected by two short, inclined grooves 510 arranged in a triangular grid pattern. This design combines pressure guiding and structural support functions, improving the uniformity of adhesion to the wafer edge and interior, providing stable support and good pressure distribution, thus achieving the practical purpose of precise support for zoned pressure control and rapid wafer pick-and-place.

[0032] A preferred embodiment is shown in Figures 5 and 6, wherein the balance ring frame 2 is a disk 23 with a central axis 21, and the outer diaphragm seat 22 is a multi-layered outwardly expanding stepped circular plate. The bottom of the disk 23 is integrally connected to the bottom of the central axis 21 to form a triangular pyramid-shaped reinforcing wall 25.

[0033] In a preferred embodiment, the balance ring frame 2 is made of aluminum alloy or stainless steel, and the carrier 10 is made of aluminum alloy or stainless steel. Multiple hollow holes 101 are provided on its surface at intervals to reduce weight. In a preferred embodiment, a groove 110 is further provided on the carrier 10, and the multiple hollow holes 101 are spaced around the groove 110.

[0034] This allows the balance ring frame 2 to be made of stainless steel, making it more robust and stable. Although the local changes will increase the weight, multiple perforated holes 101 are provided in the middle of the groove 110 on the carrier 10, so that the weight is balanced with the reinforced balance ring frame 2. This avoids the loss of system balance and synchronization due to uneven weight distribution after assembly, and effectively maintains the overall efficiency of CMP and the stability of the process.

[0035] Compared with existing technologies, the improved structure of the chemical mechanical polishing head of this invention has the following advantages: the overall design and material application have been optimized, improving the shortcomings of current polishing devices in terms of strength, weight, and adsorption stability, thereby enhancing overall process efficiency and equipment lifespan. The film fixing ring 5 includes multiple circular suction cup-shaped grooves 50 forming a bead chain, which can be further arranged in a radial triangular grid pattern to achieve multi-point distributed vacuum adsorption and positive pressure release, as well as pressure zone control according to a zone-by-zone strategy, improving wafer bonding uniformity and polishing stability. This gives the overall structure advantages such as stable adsorption, lightweight and high strength, and precise pressure division, improving wafer bonding uniformity and polishing stability, and making it more suitable for next-generation semiconductor wafer planarization processes.

[0036] However, the above description is only a preferred embodiment of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, all equivalent changes and modifications made in accordance with the scope of the present utility model patent application and the contents of the specification should fall within the scope of the present utility model patent.

Claims

1. An improved structure for a chemical mechanical grinding head, characterized in that: The device includes at least one gas splitter, a balance ring frame, an elastic diaphragm, a fixing ring, and a diaphragm fixing ring. The gas splitter is located above the center of an annular carrier and has at least one gas flow channel. The balance ring frame is fitted within the carrier and forms an airtight cavity with the gas splitter, with a diaphragm seat surrounding its side. The elastic diaphragm is located on the diaphragm seat and is used for elastic expansion and contraction to transmit pressure. The fixing ring is located below the carrier, framing the periphery of the diaphragm fixing ring. The diaphragm fixing ring is located below the balance ring frame and has multiple concentrically arranged grooves on its surface that are connected to a pressure control system. Each groove has a spaced circular suction cup-shaped groove, forming a ring-shaped beaded chain arrangement. The suction cup-shaped grooves adsorb the wafer in suction mode and release the wafer in positive pressure mode, supporting independent pressure adjustment in different zones.

2. The improved chemical mechanical grinding head structure according to claim 1, characterized in that: The balance ring frame is a disc with a central axis, and the diaphragm seat around it is a multi-layered, outwardly expanding stepped disc. The bottom of the disc is integrally connected to the bottom of the central axis to form a triangular pyramid-shaped reinforcing wall.

3. The improved chemical mechanical grinding head structure according to claim 2, characterized in that: The balance ring frame is made of aluminum alloy or stainless steel, and the carrier is made of aluminum alloy or stainless steel, with multiple hollow holes spaced apart on its annular surface.

4. The improved chemical mechanical grinding head structure according to claim 3, characterized in that: The plurality of perforated spacers are arranged in a groove on the vehicle.

5. The improved chemical mechanical grinding head structure according to claim 1, characterized in that: The concentric grooves on the surface of the membrane fixing ring are arranged in two layers, an inner and an outer layer, and the circular suction cup-shaped grooves on the outer and inner layers are arranged alternately and at intervals.

6. The improved chemical mechanical grinding head structure according to claim 5, characterized in that: The circular suction cup-shaped grooves on the outer channel groove and the inner channel groove are arranged in a triangular grid pattern with two short inclined grooves connected to each other in a one-to-two manner.

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