An apparatus for chemical mechanical polishing

Abstract

The application provides a device for chemical mechanical polishing, which comprises a polishing main body, a shield and a liquid injection assembly; the shield is arranged around the polishing main body, the inside of the shield is provided with an annular flow channel, and the bottom of the flow channel is provided with a groove which is communicated with the outside; the liquid injection assembly is detachably connected with the shield and is used for injecting liquid into the flow channel, and the liquid forms an annular liquid curtain after flowing out of the groove. The moisturizing device provided by the application can make the moisturizing liquid form a liquid curtain and flow down along the side wall of the shield to carry out moisturizing, so that crystallization does not occur on the outer wall of the parts below the shield; meanwhile, compared with the traditional moisturizing mode of directly spraying the side wall, the liquid curtain formed by the application can flow down along the wall, so that liquid splashing caused by spraying to the outer wall is avoided, and secondary pollution to other areas is prevented.

Description

Technical Field

[0001] This invention belongs to the field of wafer manufacturing technology, and more specifically, relates to an apparatus for chemical mechanical polishing. Background Technology

[0002] The manufacturing process of integrated circuits is generally divided into three stages: silicon wafer manufacturing, front-end processing (chip fabrication), and back-end processing (packaging and testing). The main purpose of silicon wafer manufacturing is to transform natural raw materials (such as sand and gravel) into a wafer-like substrate. The main purpose of front-end processing (chip fabrication) is to grow circuit devices on the substrate. The front-end manufacturing process, according to technical specialization, can be mainly divided into: thin film deposition, chemical mechanical polishing (CMP), photolithography, etching, and ion implantation. Each process stage requires multiple cycles.

[0003] CMP is the most important step in wafer processing. CMP uses a combination of chemical and mechanical processes to polish the wafer surface. First, the wafer surface material reacts chemically with oxidants, catalysts, and other substances in the polishing slurry to form a relatively easy-to-remove soft layer. Then, the soft layer is removed by the mechanical action of abrasives and polishing pads in the polishing slurry, exposing the wafer surface again. Then, another chemical reaction is carried out. In this way, the polishing operation of the wafer surface is completed through the alternation of chemical and mechanical processes.

[0004] In chemical mechanical polishing (CMP) equipment, the drive module provides power to the polishing head, which then presses against the polishing pad with specific pressure to rotate and oscillate. Polishing slurry is added during the polishing process to improve efficiency; however, the slurry has a crystallizing property. During polishing, the polishing pad carries the slurry at high speed, and the slurry splashes onto areas such as the sides of the polishing drive shield and the sidewalls of the polishing head. If these areas are not promptly moisturized and cleaned, the slurry will crystallize and fall onto the polishing pad, scratching the wafer surface, reducing the machine's yield, and potentially even resulting in defective wafers. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes an apparatus for chemical mechanical polishing.

[0006] One embodiment of the present invention provides an apparatus for chemical mechanical polishing, comprising:

[0007] Polishing body, protective cover, and liquid injection assembly;

[0008] The protective cover is arranged around the polishing body, and the interior of the protective cover has an annular flow channel, with a groove at the bottom of the flow channel communicating with the outside.

[0009] The liquid injection assembly is detachably connected to the protective cover and is used to inject liquid into the flow channel. After the liquid flows out of the tank, it forms an annular liquid curtain.

[0010] In some embodiments, the polishing body includes at least two drive modules, and a support head is configured at the bottom of each drive module;

[0011] The protective cover is arranged around the outer periphery of the drive module.

[0012] In some embodiments, the polishing body further includes a rotating frame connected to the drive module, the rotating frame being used to drive a plurality of the drive modules to rotate about the center of the rotating frame.

[0013] In some embodiments, the groove is aligned with the outer wall of the support head, and the annular liquid curtain flows down along the outer wall of the support head.

[0014] In some embodiments, the side wall of the protective cover is provided with an injection port communicating with the flow channel, and the outlet end of the injection assembly is configured to correspond to the position of the injection port.

[0015] In some embodiments, the protective cover is divided into an upper part and a lower part, the outer circumferential diameter of the upper part is larger than the outer circumferential diameter of the lower part, and the outer wall surface of the upper part protrudes beyond the outer wall surface of the lower part.

[0016] The flow channel is opened inside the upper part of the protective cover, and the opening of the groove is located on the bottom surface of the protruding part of the upper part of the protective cover.

[0017] In some embodiments, the trough is aligned with the outer wall of the lower part of the shield, and the liquid flowing out of the trough flows down the outer wall of the lower part of the shield to form the annular liquid curtain.

[0018] In some embodiments, the injection assembly includes:

[0019] A fixed base with an axially continuous travel cavity inside;

[0020] The liquid injection component extends through the stroke cavity and has a through-flow liquid injection channel along the axial direction inside.

[0021] An elastic element is located within the stroke cavity and surrounding the injection element. The protective cover abuts against or detaches from one end of the injection element, causing the elastic element to be compressed or reset.

[0022] In some embodiments, a sealing element is provided at the end of the injection component that contacts the protective cover.

[0023] In some embodiments, the outer wall of the injection component is formed with a limiting structure for docking, and a cap is disposed at one open end of the fixing base to close the fixing base, the cap abutting against the limiting structure.

[0024] The beneficial effects of the embodiments of the present invention include:

[0025] The protective cover and injection assembly provided by this invention allow the moisturizing liquid to flow out through the cover, forming an annular liquid curtain that flows down the side wall of the cover, moisturizing various components below and preventing crystallization on the outer walls of the components below the cover. Furthermore, compared to traditional spray moisturizing methods that spray directly onto the side wall, the annular liquid curtain formed by this invention can flow slowly down the outer wall of the components, preventing secondary contamination of other areas due to liquid splashing when sprayed onto the outer wall. Attached Figure Description

[0026] The advantages of the present invention will become clearer and easier to understand through the following detailed description in conjunction with the accompanying drawings, which are merely illustrative and do not limit the scope of protection of the present invention, wherein:

[0027] Figure 1 This is a schematic diagram of the structure of an apparatus for chemical mechanical polishing provided in an embodiment of the present invention;

[0028] Figure 2 This is a front view of an apparatus for chemical mechanical polishing provided in an embodiment of the present invention;

[0029] Figure 3 This is a front view of a protective cover provided in an embodiment of the present invention;

[0030] Figure 4 This is a diagram showing the docking state of the protective cover and the liquid injection component according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the structure of a protective cover provided in an embodiment of the present invention;

[0032] Figure 6 This is a partial cross-sectional view of a protective cover provided in an embodiment of the present invention. Detailed Implementation

[0033] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0034] The accompanying drawings in this specification are schematic diagrams to aid in illustrating the concept of the invention, and schematically show the shapes of the various parts and their interrelationships. It should be understood that, in order to clearly demonstrate the structure of the components in the embodiments of the invention, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings. The technical solutions of the invention will be further described below through specific embodiments.

[0035] In this invention, "Chemical Mechanical Polishing (CMP)" is also called "Chemical Mechanical Planarization (CMP)," and the wafer (W) is also called the substrate (Substrate), with the same meaning and actual function.

[0036] Figure 1 An apparatus for chemical mechanical polishing according to an embodiment of the present invention includes:

[0037] Polishing body, protective cover 220 and liquid injection assembly 210;

[0038] The protective cover 220 surrounds the polishing body. The interior of the protective cover 220 has an annular flow channel 224, and the bottom of the flow channel 224 has a groove 225 communicating with the outside (e.g., ...). Figure 6 (as shown);

[0039] The liquid injection assembly 210 is detachably connected to the protective cover 220 and is used to inject liquid into the flow channel 224. After the liquid flows out of the tank 225, it forms an annular liquid curtain.

[0040] In this embodiment, the injection component 210 injects moisturizing liquid into the flow channel 224 inside the protective cover 220. The liquid flows through the flow channel 224 to various parts of the circumference of the protective cover 220 and exits from the groove 225 at the bottom of the flow channel 224, forming an annular liquid curtain. This annular liquid curtain moisturizes various components in the area below the protective cover 220, including but not limited to the outer wall of the area below the protective cover 220 and the side wall of the polishing head 130, preventing crystallization of the outer wall of the components below the protective cover 220 due to the presence of polishing liquid. Compared to the traditional spray moisturizing method facing the side wall, the liquid curtain formed in this embodiment can flow down the wall without splashing liquid when sprayed onto the outer wall, preventing secondary contamination of other areas.

[0041] Figure 1 In the embodiment shown, the polishing body includes at least two drive modules 120, and a support head is disposed at the bottom of the drive module 120.

[0042] The protective cover 220 is arranged around the outer periphery of the drive module 120.

[0043] Figure 1 In the embodiment shown, the polishing body also includes a rotating frame 110 connected to the drive module 120. The rotating frame 110 is used to drive multiple drive modules 120 to rotate about the center of the rotating frame 110.

[0044] Chemical mechanical polishing equipment may include multiple drive modules 120, such as Figure 2 As shown, the system includes a first drive module 121 and a second drive module 122. The use of two sets of drive modules 120 significantly improves the polishing efficiency of the machine. The first drive module 121 and the second drive module 122 are mounted side-by-side below the rotating frame 110. A first polishing head 131 and a second polishing head 132 are respectively positioned at the bottom of the first drive module 121 and the second drive module 122. Each drive module 120 can oscillate linearly, thereby driving the polishing head 130 at the bottom to move linearly back and forth, meeting the process requirements during polishing. Simultaneously, the first drive module 121 and the second drive module 122 can rotate along the central axis of the rotating frame 110, enabling rapid switching of the polishing head 130's position.

[0045] In this embodiment, the linear oscillation of the drive module 120 enables docking and disengagement with the injection component 210. During use, the injection component 210 remains fixed. When the drive module 120 and the protective cover 220 move towards the injection component 210, the injection port 223 on the protective cover 220 docks with the injection component 210, and the injection component 210 injects moisturizing liquid into the flow channel 224 within the protective cover 220. When the drive module 120 and the protective cover 220 move away from the injection component 210, the injection port 223 on the protective cover 220 disengages from the injection component 210. Alternatively, the injection component 210 can also move synchronously towards the drive module 120. The relative movement of the protective cover 220 and the injection component 210 completes the docking of the injection port 223 with the injection element 211, while the opposite movement of the protective cover 220 and the injection component 210 completes the disengagement of the injection port 223 from the injection element 211.

[0046] exist Figure 1 In the embodiment shown, after the protective cover 220 of the first drive module 121 has completed moisturizing, the rotating frame drives the first drive module 121 and the second drive module 122 to rotate, switching the second drive module 122 to the moisturizing station, and injecting liquid to moisturize the protective cover 220 of the second drive module 122 through the liquid injection component 210.

[0047] In this embodiment, the groove 225 at the bottom of the flow channel 224 is aligned with the outer wall of the support head, and the annular liquid curtain flows down along the outer wall of the support head.

[0048] In order to moisturize the sidewall of the polishing head 130 below the shield 220, it is necessary to control the formation position of the annular liquid curtain, that is, the groove 225 at the bottom of the flow channel 224 needs to be aligned with the sidewall of the polishing head 130 so that the moisturizing liquid curtain can flow down along the sidewall of the polishing head 130.

[0049] Figure 5 In the embodiment shown, the side wall of the protective cover 220 is provided with an injection port 223 that communicates with the flow channel 224, and the outlet end 217 of the injection assembly 210 is configured to correspond to the position of the injection port 223.

[0050] Figure 3 In the illustrated embodiment, the shield 220 is divided into an upper shield 221 and a lower shield 222. The outer circumferential diameter of the upper shield 221 is larger than that of the lower shield 222, and the outer wall surface of the upper shield 221 protrudes beyond the outer wall surface of the lower shield 222. A flow channel 224 is formed inside the upper shield 221, and the opening of the groove 225 is located on the bottom surface of the protruding portion of the upper shield 221.

[0051] The trough 225 is aligned with the outer wall of the lower part 222 of the shield, and the liquid flowing out of the trough 225 flows down the outer wall of the lower part 222 of the shield to form an annular liquid curtain.

[0052] In this embodiment, the moisturizing liquid flows out from the groove 225 on the bottom surface of the upper part 221 of the protective cover to form an annular liquid curtain. The groove 225 is aligned with the outer wall of the lower part 222 of the protective cover, so that the moisturizing liquid flowing out from the groove 225 flows out along the circumferential outer wall of the lower part 222 of the protective cover to form an annular liquid curtain, thereby moisturizing the circumferential outer wall of the lower part 222 of the protective cover and the side wall of the polishing head 130 below it.

[0053] Figure 4 In the illustrated embodiment, the injection assembly 210 includes:

[0054] The fixed base 215 has an axially penetrating travel cavity inside;

[0055] The liquid injection component 211 has a through-stroke cavity and an axial liquid injection channel 216 inside.

[0056] The elastic element 212 is located in the stroke cavity and is disposed around the liquid injection element 211. The protective cover 220 abuts against or detaches from one end of the liquid injection element 211, so that the elastic element 212 is compressed or reset.

[0057] In this embodiment, the injection component 211 can move along the axial direction of the fixed base 215. When the side wall of the protective cover 220 abuts against one end of the injection component 211, the elastic element 212 inside the fixed base 215 will be compressed, realizing the displacement tolerance of the fixed base 215 in the extension and contraction direction. At the same time, the outlet end 217 of the injection channel 216 is connected to the injection port 223 to realize the connection of the moisturizing water channel. When the moisturizing water channel is opened, the moisturizing liquid is injected into the flow channel 224 inside the protective cover 220 through the injection component 210 from the injection port 223 and fills the entire flow channel 224. It flows down through the slit slot 225 at the bottom of the flow channel 224 to form an annular liquid curtain, which performs 360° circumferential moisturizing operation on each component below the protective cover 220.

[0058] Figure 4 In the embodiment shown, a sealing element 213 is provided at the end of the liquid injection component 211 that contacts the protective cover 220.

[0059] In this embodiment, a sealing element 213 is added between the injection port 211 and the protective cover 220. When the injection port 223 is tightly connected with the injection port 211, the sealing element 213 can further improve the sealing between the injection port 223 and the outlet end 217 of the injection port 211, preventing the moisturizing liquid from leaking due to sealing problems after the injection port 223 and the injection port 211 are connected.

[0060] It should be noted that this embodiment does not impose specific requirements or special limitations on the structure of the injection component 211, the elastic component 212, and the sealing component 213. For example, the injection component 211 can be a rod-shaped structure, the elastic component 212 can be a spring, and the sealing component 213 can be a sealing ring, etc.

[0061] Figure 4 In the illustrated embodiment, the outer wall of the injection component 211 is formed with a limiting structure for docking, and a pressure cap 214 is disposed at the open end of the fixing base 215 to close the fixing base 215, with the pressure cap 214 abutting against the limiting structure. Figure 4 In the embodiment shown, the pressure cap 214 is an annular structure with an end face width greater than that of the fixed base 215. The outer wall surface of the pressure cap 214 is aligned with the outer wall surface of the fixed base 215, and the inner wall surface of the pressure cap 214 protrudes inward from the inner wall surface of the fixed base 215, thereby forming a stepped surface in the contact area between the pressure cap 214 and the fixed base 215.

[0062] Figure 4 In the embodiment shown, the travel cavity in the fixed base 215 is divided into a first travel cavity and a second travel cavity along the axial direction of the fixed base 215. The first travel cavity is closer to the cover 220, the diameter of the first travel cavity is larger than the diameter of the second travel cavity, and a stepped surface is formed at the joint between the first travel cavity and the second travel cavity.

[0063] The limiting structure provided on the outer wall of the liquid injection component 211 can be an annular boss formed along the circumference. Before liquid injection, the elastic component 212 is in the initial state, and one end face of the annular boss abuts against the inner side of the fixed base 215. At this time, there is a gap between the other end face of the annular boss and the stepped surface in the stroke cavity. When the protective cover 220 moves toward the injection assembly 210 and / or the injection assembly 210 moves toward the protective cover 220, the injection port 223 on the side wall of the protective cover 220 abuts against the outlet end 217 of the injection element 211, the elastic element 212 is compressed, one end face of the annular boss disengages from the inner side of the pressure cap 214, and the injection element 211 moves toward the second stroke cavity until the other end face of the annular boss abuts against the stepped surface in the stroke cavity, at which point the injection element 211 stops moving. At this time, the injection port 223 and the outlet end 217 of the injection element 211 are tightly connected, realizing the communication between the injection channel 216 of the injection element 211 and the flow channel 224 in the protective cover 220. After the injection is completed, the protective cover 220 disengages from the injection assembly 210, and under the action of the elastic element 212, the injection element 211 moves toward the pressure cap 214, and the injection element 211 and the elastic element 212 are reset. In this embodiment, the combination of the limiting structure, the pressure cap 214 and the elastic element 212 can provide a certain pre-pressure to the liquid injection element 211, ensuring that the fixed base 215 can return to the set position after it is separated from the protective cover 220.

[0064] This embodiment describes the docking and disengagement process between the protective cover 220 and the liquid injection assembly 210 as follows:

[0065] When the drive module 120 is in the moisturizing position, it will drive the polishing head 130 to swing linearly. Each drive module 120 corresponds to a protective cover 220 and shares a liquid injection component 211. The drive module 120 is driven to rotate circumferentially around the center of the support module through the support module, thereby switching different protective covers 220 to the moisturizing position. The docking and disengagement between the protective cover 220 and the liquid injection component 210 are achieved by the linear swing of the drive module 120 and / or the displacement of the liquid injection component 210.

[0066] When the injection port 223 of the protective cover 220 is connected to the outlet end 217 of the injection component 211, a continuous moisturizing water channel is formed. The moisturizing liquid is injected into the flow channel 224 of the protective cover 220 through the injection component 211, and flows out through the groove 225 at the bottom of the flow channel 224 to form an annular liquid curtain, which performs 360° circumferential moisturizing operation on the outer wall of the lower part 222 of the protective cover and the polishing head 130 and other components below the protective cover 220. After moisturizing is completed, the moisturizing water channel is closed, and the injection component 211 and the protective cover 220 are disengaged with the displacement of the drive module 120 and / or the injection assembly 210.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0068] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An apparatus for chemical mechanical polishing, characterized by comprising: include: Polishing body, protective cover, and liquid injection assembly; The protective cover is arranged around the polishing body, and the interior of the protective cover has an annular flow channel, with a groove at the bottom of the flow channel communicating with the outside. The liquid injection assembly is detachably connected to the protective cover and is used to inject liquid into the flow channel. After the liquid flows out of the tank, it forms an annular liquid curtain. The protective cover is divided into an upper part and a lower part. The outer diameter of the upper part is larger than that of the lower part. The outer wall surface of the upper part protrudes beyond the outer wall surface of the lower part. The flow channel is opened inside the upper part of the protective cover, and the opening of the groove is located on the bottom surface of the protruding part of the upper part of the protective cover; The trough is aligned with the outer wall of the lower part of the protective cover, and the liquid flowing out of the trough flows down the outer wall of the lower part of the protective cover to form an annular liquid curtain; The side wall of the protective cover is provided with an injection port that communicates with the flow channel, and the outlet end of the injection component is configured to correspond to the position of the injection port. When the drive module and the protective cover of the polishing body move toward the liquid injection component, the liquid injection port on the protective cover connects with the liquid injection component, and the liquid injection component injects moisturizing liquid into the flow channel inside the protective cover; when the drive module and the protective cover move away from the liquid injection component, the liquid injection port on the protective cover disengages from the liquid injection component.

2. The apparatus of claim 1, wherein, The polishing body includes at least two drive modules, and a support head is configured at the bottom of each drive module; The protective cover is arranged around the outer periphery of the drive module.

3. The apparatus of claim 2, wherein, The polishing body also includes a rotating frame connected to the drive module, which drives multiple drive modules to rotate about the center of the rotating frame.

4. The apparatus of claim 2, wherein, The groove is aligned with the outer wall of the bearing head, and the annular liquid curtain flows down along the outer wall of the bearing head.

5. The apparatus according to claim 1, characterized in that, The injection assembly includes: A fixed base with an axially continuous travel cavity inside; The liquid injection component extends through the stroke cavity and has a through-flow liquid injection channel along the axial direction inside. An elastic element is located within the stroke cavity and surrounding the injection element. The protective cover abuts against or detaches from one end of the injection element, causing the elastic element to be compressed or reset.

6. The apparatus of claim 5, wherein, A sealing element is provided at the end of the injection component that contacts the protective cover.

7. The apparatus of claim 5, wherein, The outer wall of the injection component is formed with a limiting structure for docking, and a pressure cap is provided at the open end of the fixed base to close the fixed base, the pressure cap abutting against the limiting structure.

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