Fixed finishing device

Abstract

The utility model discloses a fixed type trimming device which comprises a grinding head and a connector, the connector is arranged in the vertical direction, the grinding head is arranged at the bottom of the connector and movably connected with the connector, the diameter R of the grinding head is larger than the diameter r of a wafer polishing head, the grinding head forms a polishing belt on a polishing pad, and the diameter r of the polishing belt is larger than the diameter r of the wafer polishing head. The wafer is polished within the range of the polishing belt. Due to the fact that the fixed type structural design is adopted, the size of the grinding disc can be greatly reduced compared with the prior art, and due to the fact that the center area of the grinding disc is not used, the use amount of the polishing pad can be greatly reduced. Due to the fact that the connector adopts a vertical downward pressing mode, the stress of the grinding head on all points on the polishing pad is more uniform, the polishing pad is more uniformly trimmed, and the risks of polishing pad damage and wafer secondary pollution caused by non-uniform trimming are eliminated.

Description

Technical Field

[0001] This utility model relates to the field of CMP polishing technology, and more specifically, to a fixed dressing device. Background Technology

[0002] In the chemical mechanical polishing (CMP) process for semiconductor wafers, pad dressing is a crucial step in maintaining surface uniformity and process stability. Traditional dressing equipment (such as...) Figure 1 As shown, a swing-arm structure is typically used to drive the dresser. The swing arm applies downward pressure to dress the polishing pad. Its advantage lies in the fact that it has no requirement for the diameter of the grinding head, and the swing arm can achieve zero-dead-angle dressing of the polishing pad. However, this structure has significant drawbacks: due to the dynamic swinging characteristics of the swing arm, the applied pressure is unevenly distributed on the dresser surface. This may cause some points of the grinding head to be pressed too tightly, while others may not contact the polishing pad, resulting in uneven wear of the grinding head and damage to the polishing pad. The bumps, depressions, or residual contaminants (such as abrasive buildup and debris) on the polishing pad surface caused by uneven dressing will cause uneven friction with the wafer surface during subsequent polishing, leading to scratches, depressions, or uneven thickness defects on the wafer surface, resulting in decreased wafer yield or even scrap. Furthermore, the dynamic swinging mode of traditional dressers makes it difficult to achieve uniform distribution of polishing fluid in the dressing area, further exacerbating the instability of the dressing process and creating a vicious cycle. Therefore, how to achieve uniform distribution of dressing pressure to eliminate the risk of polishing pad damage and secondary contamination of wafers caused by uneven dressing is the technical problem to be solved by this utility model. Utility Model Content

[0003] The utility model description section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This utility model description section is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0004] To at least partially solve the above problems, this utility model provides a fixed dressing device, including: a grinding head and a connector, the connector being arranged in a vertical direction, the grinding head being disposed at the bottom of the connector and movably connected to the connector, the diameter R of the grinding head being larger than the diameter r of the wafer polishing head, the grinding head forming a polishing belt on the polishing pad, and the wafer being polished within the range of the polishing belt.

[0005] Preferably, the connector is a vertical pressurizing device used to apply pressure to the grinding head in the vertical direction.

[0006] Preferably, a pressure detection module is provided between the grinding head and the connector.

[0007] Preferably, the pressure detection module consists of several concentric detection rings, with the center of rotation of the grinding head as the center of the circle.

[0008] Preferably, the detection ring consists of at least one pressure module, and the distance between any two adjacent pressure modules is the same.

[0009] Preferably, the connector is provided with an infusion tube, one end of which is connected to the liquid supply device and the other end extends to the bottom of the connector. The center of the grinding head is provided with an outlet hole, and the infusion tube communicates with the outlet hole.

[0010] Preferably, the inner diameter of the outlet hole is not less than the inner diameter of the infusion tube.

[0011] Preferably, the bottom surface of the grinding head is composed of a plurality of grinding strips, which extend spirally radially from the liquid outlet to the edge of the grinding head, and there is a first distance H between two adjacent grinding strips.

[0012] Preferably, the end of the grinding strip near the liquid outlet hole has a second distance h between it and the edge of the liquid outlet hole.

[0013] Preferably, the sidewall of the grinding strip is provided with an inclined surface.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects:

[0015] This invention abandons the traditional "swing arm" dressing method and adopts a "fixed" dressing method. The connector is vertically positioned and can function as a vertical pressure device, applying uniform pressure to the grinding head in the vertical direction. This vertical pressure device can be a commercially available product or existing technology. Because of the "fixed" and "vertical downward pressure" design, the coverage area of ​​the polishing band formed by the grinding head on the polishing pad is inevitably reduced, making it impossible to fully dress the polishing pad. Therefore, the diameter R of the grinding head needs to be larger than the diameter r of the wafer polishing head, ensuring that the wafer polishing head always polishes within the polishing band area. The "fixed" structural design also allows for a significant reduction in the size of the grinding disc compared to existing technologies. Furthermore, because the central area of ​​the grinding disc is not used, the amount of polishing pad used is greatly reduced. The "vertical downward pressure" method of the connector ensures more uniform force distribution on the polishing pad at all points, resulting in more even dressing of the polishing pad and eliminating the risk of polishing pad damage and secondary wafer contamination caused by uneven dressing.

[0016] The fixed trimming device described in this utility model, other advantages, objectives and features of this utility model will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this utility model. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of existing technology.

[0019] Figure 2 This is a schematic diagram of the fixed trimming device described in this utility model.

[0020] Figure 3 This is a bottom view of the grinding head when the inner diameter of the liquid outlet is the same as the inner diameter of the infusion tube (grinding strips are not shown).

[0021] Figure 4 This is a bottom view of the grinding head (the shaded area represents the inclined plane).

[0022] Figure 5 This is a schematic diagram of the grinding head.

[0023] Figure 6 This is a cross-sectional view of the grinding bar and grinding head.

[0024] In the diagram: 1 Grinding head, 2 Connector, 3 Polishing belt, 4 Infusion tube, 5 Infusion hole, 6 Grinding strip, 7 Bevel, 100 Dresser, 200 Grinding disc, 300 Wafer polishing head, 400 Liquid supply equipment. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0026] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0027] like Figures 1-6 As shown, this utility model provides a fixed dressing device, including: a grinding head 1 and a connector 2. The connector 2 is arranged vertically, and the grinding head 1 is disposed at the bottom of the connector 2 and movably connected to the connector 2. The diameter R of the grinding head 1 is larger than the diameter r of the wafer polishing head 300. The grinding head 1 forms a polishing belt 3 on a polishing pad, and the wafer is polished within the range of the polishing belt 3. The connector 2 is a vertical pressure device used to apply pressure to the grinding head 1 in the vertical direction.

[0028] The working principle and beneficial effects of the above technical solution: This utility model abandons the traditional "swing arm" dressing method and adopts a "fixed" dressing method. The connector 2 is arranged vertically and can be a vertical pressure device to uniformly apply pressure to the grinding head 1 in the vertical direction. The vertical pressure device can be a commercially available product or existing technology. Because of the "fixed" and "vertical downward pressure" design, the coverage area of ​​the polishing band 3 formed by the grinding head 1 on the polishing pad is inevitably reduced, making it impossible to completely dress the polishing pad. Therefore, the diameter R of the grinding head 1 needs to be larger than the diameter r of the wafer polishing head 300, so that the wafer polishing head 300 can always polish within the polishing band 3. Also, because of the "fixed" structural design, the size of the grinding disc 200 can be significantly reduced compared to existing technologies, and because the central area of ​​the grinding disc 200 is not used, the amount of polishing pad used can be significantly reduced. Because connector 2 uses a "vertical downward pressing" method, the force on the polishing head 1 is more uniform at each point on the polishing pad, which makes the polishing pad more uniformly dressed and eliminates the risk of polishing pad damage and secondary wafer contamination caused by uneven dressing.

[0029] Furthermore, to ensure the uniformity of the force exerted by the grinding head 1 on the polishing pad, a pressure detection module is provided between the grinding head 1 and the connector 2, or on the bottom surface of the grinding head 1 (because it needs to contact the polishing pad and participate in the polishing pad dressing; under the influence of wear and polishing fluid corrosion, the lifespan of the pressure detection module will be short, and specific commercially available products or existing technologies are required as pressure detection modules, resulting in high costs; therefore, this implementation method is generally not adopted). The pressure detection module consists of several concentric detection rings, with the rotation center of the grinding head 1 as the center. Each detection ring consists of at least three pressure modules, with the distance between any two adjacent pressure modules being equal. By arranging the pressure modules in a ring shape between the grinding head 1 and the connector 2, the force exerted at various points on the grinding head 1 can be monitored in real time.

[0030] In existing technologies, such as Figure 1 As shown, a liquid supply device 400 needs to be installed above the polishing pad 200 to continuously supply polishing liquid to the polishing pad, such as... Figure 1As shown by the solid arrow, the polishing slurry washes away contaminants on the polishing pad after it has been prepared. Because the size of the grinding head 1 in the prior art is relatively small, the polishing slurry can smoothly reach the wafer polishing head 300 for wafer polishing as the swing arm swings. However, because this utility model adopts a "fixed" design, if the external liquid supply device 400 of the prior art is still used, the polishing slurry will be blocked by the grinding head 1 and will not be able to reach the wafer polishing head 300. Furthermore, it will not be able to wash away the contaminants generated by the grinding head 1 on the side away from the liquid supply device 400. To address the aforementioned issues, an infusion tube 4 is incorporated within the connector 2. It should be noted that the infusion tube 4 can be an external conduit or a pipe or channel integrated into the connector 2. One end of the infusion tube 4 connects to the liquid supply device 400 to supply polishing fluid, while the other end extends to the bottom of the connector 2. A liquid outlet 5 is located at the rotation center of the grinding head 1, and the infusion tube 4 communicates with the outlet 5. Polishing fluid can travel from the liquid supply device 400 through the infusion tube 4 to the outlet 5 and be sprayed onto the polishing pad. This allows the polishing fluid to diffuse from the center of the grinding head 1 outwards, achieving complete coverage of the grinding head 1. Furthermore, a portion of the polishing fluid flowing from the grinding head 1 can smoothly reach the wafer polishing head 300 for polishing. The inner diameter of the outlet 5 is not smaller than the inner diameter of the infusion tube 4, allowing the outlet 5 to form a small receiving cavity to hold the polishing fluid, thus enabling the polishing fluid to diffuse evenly from the center of the grinding head 1 outwards.

[0031] Furthermore, because this utility model adopts a structural design of a "fixed" connector 2 and a "built-in infusion tube 4", the structure of the grinding head 1 also needs to be adjusted accordingly. The bottom surface of the grinding head 1 is composed of several grinding strips 6, which extend spirally radially from the liquid outlet 5 towards the edge of the grinding head 1, such as... Figure 4 and Figure 5 As shown, there is a first distance H between two adjacent grinding strips 6. Because the grinding strips 6 extend radially from the center outwards in a spiral pattern, the first distance H mentioned here is the average value between two adjacent grinding strips 6. The minimum value of the first distance is H1, and H1 > 0, which is the distance between the ends of two adjacent grinding strips 6 near the liquid outlet 5. Figure 4 As shown; the maximum value of the first distance is H2, which is the distance between the ends of two adjacent grinding strips 6 furthest from the liquid outlet 5, as shown. Figure 4 As shown; the aforementioned first distance H is (H1+H2) / 2. By setting the first distance H, the polishing slurry is ensured to have a flow channel that diffuses from the center of the grinding head 1 to the outside, thereby improving the scouring efficiency of contaminants on the surface of the polishing pad and increasing the amount of polishing slurry flowing into the wafer polishing head 300.

[0032] Furthermore, the end of the grinding strip 6 near the liquid outlet 5 has a second distance h between it and the edge of the liquid outlet 5, such as... Figure 4 As shown, the second distance h allows the end of the polishing strip 6 near the liquid outlet 5 to form a cavity for storing polishing fluid, similar to the cavity formed when the inner diameter of the liquid outlet 5 is larger than the inner diameter of the infusion tube 4. Because the polishing strip 6 is set on the bottom surface of the grinding head 1 and extends towards the polishing pad, the cavity can be naturally formed by setting the second distance h, without needing to limit the inner diameter of the liquid outlet 5.

[0033] Furthermore, an inclined surface 7 is provided on the side wall of the grinding strip 6, such as... Figure 4 As shown in the shaded area, and Figure 5 and Figure 6 As shown. The inclined surface can squeeze and guide the polishing fluid between the two polishing strips 6 during grinding, and as the first distance gradually increases from H1 to H2, a space can also be formed between the inclined surface 7 and the polishing pad to temporarily store contaminants after finishing.

[0034] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0035] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A stationary dressing device, characterized in that The utility model relates to a polishing head (1) and a connector (2), the connector (2) is arranged in the vertical direction, the polishing head (1) is arranged at the bottom of the connector (2) and is movably connected with the connector (2), the diameter R of the polishing head (1) is greater than the diameter r of the wafer polishing head (300), the polishing head (1) forms a polishing belt (3) on the polishing pad, and the wafer is polished within the range of the polishing belt (3). The connector (2) is a vertical pressure device for applying pressure to the polishing head (1) in the vertical direction.

2. The stationary finishing device of claim 1, wherein A pressure detection module is arranged between the polishing head (1) and the connector (2).

3. The stationary finishing device of claim 2, wherein The pressure detection module is composed of several concentric detection rings, and the center of rotation of the polishing head (1) is taken as the center of the detection rings.

4. The stationary finishing device of claim 3, wherein The detection ring is composed of at least three pressure modules, and the distance between adjacent pressure modules is the same.

5. The stationary finishing device according to claim 4, characterized in that The connector (2) is provided with a liquid supply pipe (4), one end of the liquid supply pipe (4) is connected with a liquid supply device (400), the other end extends to the bottom of the connector (2), the center of the polishing head (1) is provided with a liquid outlet hole (5), and the liquid supply pipe (4) communicates with the liquid outlet hole (5).

6. The stationary finishing device of claim 2, wherein The inner diameter of the liquid outlet hole (5) is not less than the inner diameter of the liquid supply pipe (4).

7. The stationary finishing device according to claim 6, characterized in that The bottom surface of the polishing head (1) is composed of several grinding strips (6), the grinding strips (6) extend radially from the liquid outlet hole (5) to the edge of the polishing head (1), and the distance between adjacent grinding strips (6) is a first distance H.

8. The stationary finishing device of claim 6, wherein, The end of the grinding strip (6) close to the liquid outlet hole (5) has a second distance h from the edge of the liquid outlet hole (5).

9. The stationary finishing device of claim 8, wherein, The side wall of the grinding strip (6) is provided with an inclined surface (7).

10. The stationary finishing device of claim 8, wherein, ​

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