Grinding head and grinding device for chemical mechanical planarization

Abstract

The utility model provides a grinding head and a grinding device for chemical mechanical planarization, the grinding head comprises a main body part and a fastening ring which are detachably connected, the main body part comprises a grinding main body, a retaining ring and a clamping ring, and the retaining ring and the grinding main body are coaxially arranged and are sequentially stacked in the clamping ring; the fastening ring comprises an annular body, the annular body is arranged outside the clamping ring in a sleeving mode, an annular limiting flange is arranged on the inner wall of the bottom of the annular body, a plurality of positioning through holes are formed in the surface of the limiting flange, and the positioning through holes are used for being connected with the clamping ring. The grinding head disclosed by the utility model is locked by utilizing the fastening ring, so that the grinding head is wear-resistant and impact-resistant, and the assembling steps of parts and components are simplified.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical mechanical planarization and relates to a polishing head and a polishing device used for chemical mechanical planarization. Background Art

[0002] Chemical Mechanical Polish (CMP) refers to the removal of deposited materials from excess and uneven parts of the silicon wafer surface through chemical corrosion and physical removal, thereby improving the flatness between circuit layers. CMP usually uses a retaining ring to adsorb and fix the wafer and control the pressure on the wafer surface. The lower part is connected to the grinding head, and the two are placed in the buckle, and then fixed with fasteners for grinding. During the CMP process, the buckle will be subject to vibration and impact as the wafer and the grinding pad move relative to each other. Therefore, the fasteners need to have characteristics such as high stability and low vibration. In addition, since the grinding fluid added during the grinding process has certain chemical corrosiveness, the material of the fasteners is required to be acid and alkali resistant.

[0003] CN209425232U discloses a novel retaining ring, comprising a retaining ring having at least three first strip-shaped grooves arranged obliquely on its upper surface and at least three bolt holes on its lower surface; the retaining ring comprises a stainless steel annular body, the outer surface of which is wrapped with a plastic layer. The plastic layer is wrapped around the stainless steel annular body, and the surface of the annular body is provided with multiple strip-shaped grooves. After injection molding using an injection molding machine, the connection between the plastic layer and the annular body is more stable, thereby enhancing structural strength, increasing service life, and reducing production costs.

[0004] CN112405331A discloses a wafer grinding device, comprising a grinding table with a grinding pad for grinding the surface of a wafer; a supply arm, located above the grinding pad, for conveying grinding liquid to the grinding pad; a wafer carrier, located above the grinding pad, for pressing the wafer against the grinding pad, the wafer carrier having a bearing surface and a non-bearing surface, the bearing surface being in contact with the wafer; an adhesive tape is adhered to the side wall of the supply arm and / or the non-bearing surface of the wafer carrier, and the surface roughness of the adhesive tape is less than or equal to a preset surface roughness.

[0005] CN117444839A discloses a grinding head and chemical mechanical polishing equipment, which includes a main body, an edge control ring, an edge holding assembly, an elastic connector, a carrier and a flange assembly; the lower surface of the elastic connector, the upper end surface of the edge control ring and the outer peripheral wall of the carrier boss of the main body are combined to form a first pressure chamber, the lower surface of the carrier, the upper end surface of the edge control ring and the upper surface of the elastic connector are combined to form a second pressure chamber, and the flange assembly, the carrier, the elastic connector and the main body are combined to form a third pressure chamber; the edge control ring is controlled by the first pressure chamber, and the edge holding assembly is controlled by the second pressure chamber.

[0006] Traditional fasteners are all made of metal and formed through turning and milling processes. The preparation process is relatively cumbersome and the manufacturing cost is high. In order to reduce the wear between them and the buckle and reduce the vibration between the two during movement, a rubber pad with a buffering effect is often placed between the two, resulting in an increase in the number of assembly parts and assembly steps of the overall grinding head. In addition, after long-term grinding, a layer of rust will appear on the surface of the metal fasteners due to the corrosive effect of the grinding fluid. If the rust layer falls off, it may cause scratches on the wafer surface and reduce the yield of the finished product. Utility Model Content

[0007] In response to the shortcomings of the existing technology, the purpose of the present invention is to provide a grinding head and grinding device for chemical mechanical planarization, which uses a fastening ring to achieve locking, has high impact resistance, does not require the use of rubber gaskets, simplifies the assembly process, and reduces the weight of the grinding head, which is conducive to improving production efficiency.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] In the first aspect, the utility model provides a grinding head for chemical mechanical planarization, wherein the grinding head includes a main body and a fastening ring that are detachably connected, the main body including a grinding body, a retaining ring and a clamping ring, the retaining ring and the grinding body are coaxially arranged and stacked in sequence inside the clamping ring; the fastening ring includes an annular body, the annular body is sleeved on the outside of the clamping ring, the bottom inner wall of the annular body is provided with an annular limiting flange, the surface of the limiting flange is provided with a plurality of positioning through holes, and the positioning through holes are used to connect the clamping ring.

[0010] The utility model uses a clamping ring to fix the grinding body and the retaining ring, and then uses a fastening ring for locking, which simplifies the assembly process, improves the overall stability and impact resistance, and prevents the problem of uneven grinding of the wafer surface due to vibration of the clamping ring. Compared with the traditional grinding head, there is no need to set a rubber gasket, which reduces the number of assembled parts, reduces the weight of the grinding head, and increases the service life of the product.

[0011] As a preferred technical solution of the present invention, the annular body is a thermoplastic polyester ring.

[0012] The annular body of the utility model is formed by injection molding, and has high impact resistance, stability and acid and alkali resistance. It eliminates the need for rubber gaskets, preventing the material surface from being corroded by grinding fluid, causing the rust layer on the surface of the parts to fall off, and causing the wafer surface to be scratched, thereby effectively improving the cost-effectiveness and service life of the overall product.

[0013] As a preferred technical solution of the present invention, the end surface of the limiting flange close to the clamping ring is a horizontal surface.

[0014] The cross section of the fastening ring in the utility model is "L" shaped and fits tightly with the clamping ring, which improves the overall stability and greatly simplifies the assembly process.

[0015] As a preferred technical solution of the present invention, the width of the limiting flange is 3.8~4.2mm, for example, it can be 3.8mm, 3.82mm, 3.85mm, 3.9mm, 3.92mm, 3.96mm, 4.0mm, 4.05mm, 4.1mm, 4.12mm, 4.15mm or 4.2mm, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] As a preferred technical solution of the present invention, the positioning through hole is a screw hole.

[0017] As a preferred technical solution of the present invention, an annular limiting groove is provided along the inner surface of the clamping ring, and the limiting groove is clamped to the grinding body.

[0018] As a preferred technical solution of the present invention, the inner surface of the clamping ring is further provided with a locking thread.

[0019] The utility model increases the friction performance between the clamping ring and the grinding body by arranging the locking thread, avoids rotation during the grinding process, and is conducive to improving the grinding effect.

[0020] As a preferred technical solution of the present invention, the thickness of the retaining ring is 16 to 25 mm, for example, it can be 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm or 25 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] As a preferred technical solution of the present invention, a drive shaft is vertically provided at one end of the grinding body away from the retaining ring.

[0022] In a second aspect, the present invention provides a grinding device, which includes the grinding head for chemical mechanical planarization described in the first aspect.

[0023] The grinding device provided by the present invention also includes a polishing disc, a dressing assembly, a liquid supply assembly and a pressure drive assembly, etc. that are well known to those skilled in the art. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection. The present invention does not make special requirements or specific limitations on this.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] The utility model provides a grinding head and grinding device for chemical mechanical planarization, which have high impact resistance and acid and alkali resistance, strong structural stability, ensure the uniformity of grinding, avoid damage to the wafer surface during the grinding process, and extend the service life of the product. In addition, the counterweight is small, the number of assembled parts is small, and assembly is convenient, which greatly reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of a grinding head provided in Example 1 of the present utility model;

[0027] Figure 2 A cross-sectional view of a fastening ring provided in Example 1 of the present utility model;

[0028] Figure 3 A schematic structural diagram of the grinding body provided in Example 2 of the present utility model;

[0029] Figure 4 This is a schematic structural diagram of the grinding head provided in Comparative Example 1 of the present invention.

[0030] Among them, 1-grinding body; 2-retaining ring; 3-clamping ring; 4-annular body; 5-limiting groove; 6-limiting flange; 7-positioning through hole; 8-driving shaft; 9-rubber gasket. DETAILED DESCRIPTION

[0031] It should be understood that in the description of the present invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "multiple" and "several" mean two or more.

[0032] It should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0034] In a specific embodiment, the present invention provides a grinding head for chemical mechanical planarization, the grinding head comprising a detachably connected main body and a fastening ring. The main body comprises a grinding body, a retaining ring and a clamping ring, the retaining ring being coaxially arranged with the grinding body and sequentially stacked inside the clamping ring, the grinding body being used to adsorb wafers undergoing chemical mechanical planarization and to control the pressure of various regions on the wafer surface, the retaining ring being used to fix the wafer, and the clamping ring being used to clamp and fix the grinding body and the retaining ring. The fastening ring comprises an annular body, the annular body being sleeved on the outside of the clamping ring for locking the entire main body, the bottom inner wall of the annular body being provided with an annular limiting flange for supporting the main body, the surface of the limiting flange being provided with a plurality of positioning through holes, the positioning through holes being used to connect the clamping ring.

[0035] In some embodiments, the annular body and the limiting flange are both thermoplastic polyester rings, formed using an injection molding process. Compared to traditional metal materials, the fastening ring of the present invention is wear-resistant and impact-resistant, providing a better buffering effect, preventing uneven polishing of the wafer surface caused by vibration of the clamping ring. It also has good acid and alkali resistance, preventing the rust layer on the surface of the parts from peeling off after acid and alkali corrosion, which could cause scratches on the wafer surface. Furthermore, the fastening ring can be directly assembled with the clamping ring, eliminating the rubber gasket used in traditional grinding heads and preventing corrosion of the material surface by the grinding fluid.

[0036] In some embodiments, the end face of the limiting flange close to the clamping ring is a horizontal plane, so that the cross section of the fastening ring is "L"-shaped, the width of the limiting flange is 3.8~4.2mm, preferably 3.96~4.05mm, and the positioning through hole is a screw hole. After the clamping ring is placed on the fastening ring, it is supported by the limiting flange at the bottom, and then the screw is installed in the limiting through hole to achieve locking of the clamping ring and the fastening ring.

[0037] In some embodiments, an annular limiting groove is provided along the inner surface of the clamping ring, and the limiting groove is engaged with the grinding body.

[0038] Furthermore, the inner surface of the clamping ring is also provided with a locking thread for improving the friction performance between the clamping ring and the grinding body, preventing the grinding body from rotating relative to each other during the grinding process, which is beneficial to improving the grinding effect.

[0039] In some embodiments, the retaining ring has a thickness of 16 to 25 mm.

[0040] In some embodiments, a drive shaft is vertically mounted on the end of the grinding body away from the retaining ring, forming an inverted "T"-shaped cross-section with the grinding body. A fastening ring is used to secure the main body, significantly reducing the vertical weight of the grinding head, thereby improving the equipment's composite force and, consequently, production efficiency. The drive shaft is connected to the grinding device's drive mechanism to rotate the grinding body and ensure the balance of its components.

[0041] In another specific embodiment, the utility model provides a grinding device, which includes a grinding head for chemical mechanical planarization as described in a specific embodiment. The grinding device also includes a polishing disc, a dressing component, a liquid supply component and a pressure drive component for achieving a complete process. The pressure drive component is connected to the grinding head and placed above the polishing disc, and the bottom of the grinding head is used to fix the wafer. A grinding pad is also provided between the grinding head and the polishing disc. The dressing component is provided above the polishing disc and is located on one side of the grinding head. It automatically rotates and applies a downward load for dressing the grinding pad. The liquid supply component is provided above the polishing disc and is used to provide grinding liquid to the grinding pad. During application, the grinding head carrying the wafer is placed on the polishing disc so that the wafer contacts the grinding pad. The pressure drive component drives the grinding head to rotate and move back and forth circumferentially along the surface of the polishing disc. At the same time, the polishing disc rotates automatically so that the wafer and the grinding pad are frictionally ground.

[0042] It should be noted that the grinding device must also include necessary pipelines, conventional valves and general pump equipment for realizing the complete process, but the above content does not belong to the main improvement points of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection. The present invention does not make special requirements and specific limitations on this.

[0043] Example 1

[0044] This embodiment provides a polishing head for chemical mechanical planarization, comprising a main body and a fastening ring that are detachably connected. Figure 1As shown, the main body includes a grinding body 1, a retaining ring 2 and a clamping ring 3. The retaining ring 2 is coaxially arranged with the grinding body 1, and is sequentially stacked inside the clamping ring 3. An annular limiting groove 5 is provided along the inner surface of the clamping ring 3 for clamping the grinding body 1. The inner surface of the clamping ring 3 is also provided with a locking thread to prevent the grinding body 1 from rotating relative to each other. The thickness of the retaining ring 2 is 20 mm. The fastening ring includes an annular body 4, which is made of thermoplastic polyethylene terephthalate plastic. The annular body 4 is sleeved on the outside of the clamping ring 3 to lock the entire main body. As shown Figure 2 As shown, the bottom inner wall of the annular body 4 is provided with an annular retaining flange 6 for supporting the main body. The end surface of the retaining flange 6, which is adjacent to the clamping ring 3, is horizontal and 4 mm wide. Multiple positioning holes 7 are circumferentially defined on the surface of the retaining flange 6 for screw connection to the clamping ring 3.

[0045] The fastening ring used in the grinding head of this embodiment has the characteristics of wear resistance and high impact resistance, ensuring uniform grinding of the wafer surface. At the same time, it also has good acid and alkali resistance to avoid the formation of a rust layer to scratch the wafer surface.

[0046] Example 2

[0047] This embodiment provides a polishing head for chemical mechanical planarization, which differs from the embodiment 1 in that: Figure 3 As shown, a drive shaft 8 is vertically provided at one end of the grinding body 1 away from the retaining ring 2, so that the drive shaft 8 and the grinding body 1 form a structure with an inverted "T" shape in cross section. The rest of the structure is the same as that of Example 1.

[0048] In this embodiment, the driving shaft 8 is connected to the pressure driving component of the grinding device to drive the grinding body 1 to rotate, thereby ensuring the balance of each component and achieving uniform grinding of the wafer surface.

[0049] Example 3

[0050] This embodiment provides a grinding device, comprising a polishing plate, a dressing assembly, a liquid supply assembly, a pressure drive assembly, and the grinding head of Example 2. The pressure drive assembly is connected to a drive shaft to position the grinding head above the polishing plate. The dressing assembly is disposed above the polishing plate and located to one side of the grinding head. The liquid supply assembly is disposed above the polishing plate to provide grinding liquid.

[0051] Comparative Example 1

[0052] This comparative example provides a polishing head for chemical mechanical planarization, which differs from Example 1 in that: Figure 4 As shown, the fastening ring is made of stainless steel and is connected to the clamping ring 3 via a rubber gasket 9 . The rest of the structure is the same as that of embodiment 1.

[0053] Compared with Example 1, the grinding head of Example 1 adds a rubber gasket 9 to connect the fastening ring and the clamping ring, which increases the number of assembly parts of the overall grinding head. In addition, the fastening ring is made of metal, which is easily corroded by the grinding fluid to form a rust layer, and there is a risk of scratching the wafer surface.

[0054] The applicant declares that the above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Technicians in the relevant technical field should understand that any changes or substitutions that can be easily thought of by technicians in the relevant technical field within the technical scope disclosed in the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polishing head for chemical mechanical planarization, characterized in that: The grinding head includes a main body and a fastening ring that are detachably connected. The main body includes a grinding body, a retaining ring and a clamping ring. The retaining ring is coaxially arranged with the grinding body and is sequentially stacked inside the clamping ring. The fastening ring includes an annular body, which is sleeved on the outside of the clamping ring. The bottom inner wall of the annular body is provided with an annular limiting flange, and the surface of the limiting flange is provided with a plurality of positioning through holes, which are used to connect the clamping ring.

2. The polishing head for chemical mechanical planarization according to claim 1, wherein: The annular body is a thermoplastic polyester ring.

3. The polishing head for chemical mechanical planarization according to claim 1, wherein: An end surface of the limiting flange close to the clamping ring is a horizontal surface.

4. The polishing head for chemical mechanical planarization according to claim 3, wherein: The width of the limiting flange is 3.8-4.2 mm.

5. The polishing head for chemical mechanical planarization according to claim 1, wherein: The positioning through hole is a screw hole.

6. The polishing head for chemical mechanical planarization according to claim 1, wherein: An annular limiting groove is provided along the inner surface of the clamping ring, and the limiting groove is clamped to the grinding body.

7. The polishing head for chemical mechanical planarization according to claim 1, wherein: The inner surface of the clamping ring is also provided with a locking thread.

8. The polishing head for chemical mechanical planarization according to claim 1, wherein: The thickness of the retaining ring is 16 to 25 mm.

9. The polishing head for chemical mechanical planarization according to claim 1, wherein: A driving shaft is vertically arranged on one end of the grinding body away from the retaining ring.

10. A grinding device, characterized in that: The polishing device comprises the polishing head for chemical mechanical planarization according to any one of claims 1 to 9.

Images