Driving assembly for bearing head and wafer bearing device

Abstract

The invention discloses a driving assembly for a bearing head and a wafer bearing device, the driving assembly comprises the bearing head and an upper pneumatic assembly, the bearing head is coupled to the upper pneumatic assembly through a connecting assembly, the connecting assembly comprises a positioning pin and a flange plate with a positioning pin hole, and the positioning pin and the flange plate are made of metal materials. A non-metal structure is arranged on part of or all the surface of the positioning pin, so that no metal pollutant is generated when the positioning pin makes contact with the flange plate.

Description

[0001] This application is a divisional application of the invention patent application with the application number 201911398791.7 and filed on December 30, 2019. Technical Field

[0002] The present invention belongs to the technical field of chemical mechanical polishing, and particularly relates to a driving component for a carrier head and a wafer carrying device. Background Art

[0003] Currently, chemical mechanical planarization (CMP, also known as chemical mechanical polishing) as a technology for achieving global planarization of wafers has developed into an equipment integrating technologies such as polishing, wafer transfer, in-situ measurement, and cleaning. In chemical mechanical polishing, a wafer is usually sucked onto the bottom surface of a carrier head at the lower part of a carrying device, and the surface of the wafer with a deposition layer is pressed against the upper surface of a polishing pad. The carrier head rotates in the same direction as the polishing pad under the actuation of an upper pneumatic assembly (UPA) at the upper part and applies a downward load to the wafer. At the same time, a polishing liquid is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the wafer completes chemical mechanical polishing of the wafer under the combined action of chemistry and mechanics.

[0004] Problems encountered in the prior art include that the surface of the wafer is easily scratched by metal contaminants and / or the problem of excessive metal contaminants during the chemical mechanical polishing process, which are unacceptable in the field of chip manufacturing. Especially with the continuous reduction of the chip manufacturing process, unprecedented high requirements are put forward for the metal pollution level. Generally speaking, once it is found that the surface of the wafer is scratched by metal contaminants or the metal contaminants exceed the standard, it may be necessary to replace all relevant consumables, thereby greatly increasing the cost and reducing the production efficiency. As pointed out in CN107301960A, in the semiconductor manufacturing process, metal ion contaminants are called mobile ion pollution sources, which have strong mobility in semiconductor materials and will cause oxide-polysilicon gate structure defects, increased PN junction leakage current, reduced minority carrier lifetime, and changed threshold voltage, which seriously endanger the yield and reliability of devices.

[0005] The carrier head of the wafer carrier device is an important component of the chemical mechanical polishing equipment. It is necessary to regularly load and unload the carrier head to carry out maintenance operations and replace components to ensure the service life of the carrier head. In order to accurately align the multiple air holes of the carrier head with the air holes of the upper pneumatic component, the carrier head of the wafer carrier device is positioned by a positioning pin with a connecting member of the upper pneumatic component and connected thereto via a clamp, and vice versa; the existing positioning pin is prone to scratching the installation surface of the metal connecting member during the installation process, thereby generating metal contaminants such as metal debris, metal particles, and metal grains. Similarly, the connecting member of the upper pneumatic component can also be configured with a positioning pin for positioning with the installation surface of the connecting member of the carrier head, and this upper positioning pin is also prone to scratching the connecting member of the carrier head and generating metal contaminants during the installation process. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art to a certain extent. For this purpose, the present invention provides a drive assembly for a carrier head, including a flange configured at the bottom of the drive assembly for connecting the carrier head, the flange having a positioning pin, the main body of the positioning pin being made of a metal material and having a non-metallic structure on part or all of its surface to avoid wear.

[0007] According to one aspect of the present invention, the non-metallic structure is provided at the end face of the positioning pin for inserting into the positioning pin hole of the carrier head.

[0008] According to one aspect of the present invention, the non-metallic structure is formed as a frustum of a cone, the diameter of the bottom surface of the frustum of the cone combined with the positioning pin being equal to the diameter of the combined surface of the positioning pin and the diameter of the top surface of the frustum of the cone being less than or equal to the diameter of the positioning pin.

[0009] According to one aspect of the present invention, the non-metallic structure is made of at least one of plastic, ceramic, and glass.

[0010] According to one aspect of the present invention, the plastic is a hard engineering plastic.

[0011] According to one aspect of the present invention, the hard engineering plastic is hard polyvinyl chloride, polyethylene, plexiglass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK, and / or PPS.

[0012] According to one aspect of the present invention, the non-metallic structure is made of a composite plastic containing fibers and / or graphene.

[0013] According to one aspect of the present invention, the metal material is a hard metal material without aluminum element.

[0014] Furthermore, the present invention also discloses a wafer carrier device, which includes a carrier head and an upper pneumatic assembly. The carrier head is coupled to the upper pneumatic assembly through a connection assembly. The connection assembly includes a positioning pin and two flange plates with positioning pin holes. The positioning pin is disposed at the bottom of the upper pneumatic assembly, and the positioning pin holes are correspondingly disposed on the flange plate at the top of the carrier head. Part or all of the surface of the positioning pin is provided with a non-metallic structure such that the positioning pin and the flange plate contact each other without abrasion and / or without generating metal contaminants.

[0015] Furthermore, the present invention also discloses a wafer carrier device, which includes a carrier head and an upper pneumatic assembly. The carrier head is coupled to the upper pneumatic assembly through a connection assembly. The connection assembly includes a positioning pin and two flange plates with positioning pin holes. The positioning pin is disposed at the bottom of the upper pneumatic assembly, and the positioning pin holes are correspondingly disposed on the flange plate at the top of the carrier head. The positioning pin is made of a non-metallic material.

[0016] For the drive assembly of the carrier head and a wafer carrier device according to the present invention, the structure is reasonable. Part or all of the surface of the positioning pin is provided with a non-metallic material structure, so that no metal contaminants are generated during the maintenance operation of the carrier device and when the positioning pin contacts the flange plate, solving the problems that the surface of the wafer is easily scratched by metal contaminants and / or the metal contaminants exceed the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Through the detailed description in conjunction with the following drawings, the advantages of the present invention will become clearer and easier to understand. These drawings are only schematic and do not limit the protection scope of the present invention, wherein:

[0018] Figure 1 is a schematic structural diagram of a chemical mechanical polishing device according to the present invention;

[0019] Figure 2 is a schematic structural diagram of the wafer carrier device according to the present invention;

[0020] Figure 3 is a schematic structural diagram of the carrier head according to the present invention;

[0021] Figure 4 is a schematic structural diagram of the upper pneumatic assembly according to the present invention;

[0022] Figure 5a 、 5b 、5c is a schematic structural diagram of the positioning pin according to the present invention.

[0023] Among them, the meanings of the numerical reference signs are as follows:

[0024] 100 - Chemical mechanical polishing device;

[0025] 10 - Polishing disc;

[0026] 20 - Polishing pad;

[0027] 30 - Wafer carrier device; 31 - Carrier head; 32 - Upper pneumatic component; 33 - Connection component; 331a - Lower flange; 331b - Upper flange; 332 - Locating pin; 3321a, 3321b, 3321c - Non - metallic structure; 333a, 333b - Locating pin holes; 334a, 334b - Air holes;

[0028] 40 - Dressing device; 41 - Dressing arm; 42 - Dressing head;

[0029] 50 - Polishing liquid supply device. Detailed implementation manners

[0030] The following combines specific embodiments and their accompanying drawings to elaborate on the technical solutions of the present invention in detail. The embodiments recorded herein are specific specific implementation manners of the present invention for explaining the concept of the present invention; these explanations are all explanatory and exemplary, and should not be construed as limiting the implementation manners of the present invention and the protection scope of the present invention. Except for the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims of this application and its specification. These technical solutions include technical solutions that make any obvious substitutions and modifications to the embodiments recorded herein.

[0031] The drawings in this specification are schematic diagrams to assist in explaining the concept of the present invention, schematically showing the shapes of each part and their mutual relationships. It should be understood that in order to clearly show the structures of the components in the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0032] It should be noted that the wafers in the present invention are sometimes also referred to as "substrates" or "substrates" in the industry, and their meanings are generally the same. In most cases, there is no distinction in the CMP field.

[0033] Figure 1The shown chemical mechanical polishing apparatus 100 includes a polishing platen 10, a polishing pad 20, a wafer carrier device 30, a dressing device 40, and a polishing liquid supply device 50; the polishing pad 20 is disposed on the upper surface of the polishing platen 10 and rotates therewith along the axis Ax1; the horizontally movable wafer carrier device 30 is disposed above the polishing pad 20, and the wafer W to be polished is held by suction on its lower surface; the dressing device 40 includes a dressing arm 41 and a dressing head 42, and the dressing arm 41 drives the rotating dressing head 42 to swing to dress the surface of the polishing pad 20 to a state suitable for polishing; the polishing liquid supply device 50 disperses the polishing liquid on the surface of the polishing pad 20; during the polishing operation, the wafer carrier device 30 presses the surface to be polished of the wafer W against the surface of the polishing pad 20, and the polishing liquid is distributed between the polishing pad 20 and the wafer W, and the removal of the surface material of the wafer is completed under the action of chemical mechanics.

[0034] As Figure 2 shown, the wafer carrier device 30 includes a carrier head 31 and an upper pneumatic assembly 32 (UPA, upper pneumatic assembly), the carrier head 31 is coupled to the upper pneumatic assembly 32 through a connection assembly 33, and the connection assembly 33 includes a lower flange 331a, an upper flange 331b, at least one positioning pin 332, and a clamp (not shown); the lower flange 331a is disposed on the top of the carrier head 31 for connection to the upper flange 331b at the bottom of the upper pneumatic assembly 32.

[0035] Figure 3 The carrier head 31 of the wafer carrier device 30 according to the present invention is shown, and at least one positioning pin 332, at least one positioning pin hole 333a, and a plurality of air holes 334a for communicating with the air circuit of the upper pneumatic assembly 32 are configured on the lower flange 331a at the top thereof; Figure 4 The upper pneumatic assembly 32 of the wafer carrier device 30 according to the present invention is shown, and at least one positioning pin 332, at least one positioning pin hole 333b, and a plurality of air holes 334b are configured on the upper flange 331b at the bottom thereof. The air holes 334a of the carrier head 31 and the air holes 334b of the upper pneumatic assembly 32 are precisely aligned and airtightly connected to each other, so that the upper pneumatic assembly 32 can adjust the pressure formula of the carrier head 31 by introducing / discharging gas into the carrier head 31. As an alternative embodiment, two positioning pins 332 and corresponding positioning pin holes may also be configured only on the upper flange 331b or the lower flange 331a.

[0036] When performing assembly and / or maintenance operations, the carrier head 31 needs to be lifted to accurately assemble it to the upper pneumatic component 32, so that the positioning pin 332 of the carrier head 31 is inserted into the positioning pin hole 333b of the upper pneumatic component 32 and / or so that the positioning pin 332 of the upper pneumatic component 32 is inserted into the positioning pin hole 333a of the carrier head 31, to ensure that the air holes 334a of the carrier head 31 and the air holes 334b of the upper pneumatic component 32 are precisely aligned with each other. A clamp (not shown) fastens the lower flange 331a and the upper flange 331b to achieve the assembly connection between the carrier head 31 and the upper pneumatic component 32.

[0037] As an embodiment of the present invention, as Figure 2 shown, the main bodies of the lower flange 331a, the upper flange 331b and the positioning pin 332 are made of metal materials, and at least one end face and / or its adjacent part of the positioning pin 332 has a non-metal structure. Since the hardness of the non-metal structure is much lower than that of the flange made of metal, the contact between them can prevent the positioning pin 332 from being misaligned and inserted into the positioning pin holes 333a and 333b, which may damage the surface of the flange and generate metal contamination including metal debris and / or metal particles, thereby preventing scratching of the wafer or affecting the yield rate of wafer polishing.

[0038] Figure 5a An embodiment variant of the positioning pin 332 according to the present invention is shown. The non-metal structure 3321a is sleeved on the end of the positioning pin 332. The end of the positioning pin 332 is formed in a frustum shape, and the upper diameter of the non-metal structure 3321a is smaller than its lower diameter, so that the positioning pin 332 is convenient to align with the positioning pin holes 333a and 333b and prevent the two from being misaligned, which may damage the surface of the flange and generate metal debris and / or metal particles. As a variant of this embodiment, as Figure 5b shown, the outer end of the component formed by the non-metal structure 3321b and the positioning pin 332 is a columnar structure, and the edges of the columnar structure are chamfered with arcs; As a variant of this embodiment, as Figure 5c shown, the non-metal structure 3321c can also be only arranged at the circumferential edges of the positioning pin 332, that is, the non-metal structure 3321c only needs to cover the edges of the positioning pin 332, to prevent the edges of the positioning pin 332 made of metal material from directly contacting the flanges 331a and 331b made of metal due to the misalignment of the positioning pin 332 inserted into the positioning pin holes 333a and 333b, resulting in metal contamination such as metal debris and / or metal particles.

[0039] In view of the need to strictly prevent the degree of aluminum ion contamination during the wafer production and processing process, as an aspect of this embodiment, the lower flange 331a, the upper flange 331b and the positioning pin 332 are made of hard metal materials that do not contain aluminum elements, such as stainless steel and titanium alloy, so that the number of aluminum ions can be reduced in the polishing environment and the metal contaminants can be controlled within the required range.

[0040] As another variant of the embodiment of the present invention, the non-metallic structure may also cover all the surfaces disposed on the outer peripheral side of the positioning pin 332 or cover all the outer surfaces of the positioning pin 332. When the carrier head 31 is connected and assembled with the upper pneumatic assembly 32, the setting of the non-metallic structure prevents metal contaminants from being generated when the positioning pin 332 contacts the lower flange 331a and the upper flange 331b.

[0041] As another variant of the embodiment of the present invention, the non-metallic structure 3321 has a certain thickness. Preferably, the thickness of the non-metallic structure 3321 is 0.3 mm - 3 mm. Preferably, in Figure 5a 、 Figure 5b and Figure 5c the thickness of the non-metallic structure 3321 shown is 1.2 mm.

[0042] As another variant of the embodiment of the present invention, the non-metallic structure 3321 is made of at least one material among plastic, ceramic, and glass. Preferably, the plastic is a hard engineering plastic. In some embodiments, the hard engineering plastic may be hard polyvinyl chloride, polyethylene, plexiglass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK, and / or PPS. In Figure 5a the embodiment shown, the non-metallic structure 3321 may be made of PEEK. As an aspect of this embodiment, the non-metallic structure 3321 is made of a reinforced composite plastic containing fibers and / or graphene. On the premise of preventing metal contaminants from being generated when the positioning pin 332 contacts the lower flange 331a and the upper flange 331b, the fibers and / or graphene can improve the strength of the positioning pin 332 and prevent the positioning pin 332 from being damaged during the process of transmitting torque between the upper pneumatic assembly 32 and the carrier head 31, ensuring the normal operation of the wafer carrying device; wherein, the fibers may be one or more of glass fibers, carbon fibers, boron fibers, aramid fibers, silicon carbide fibers, asbestos fibers, etc. used to enhance the strength of the plastic. The length of the fibers is 0.2 mm to 12 mm, preferably 1 mm to 5 mm, and the weight ratio of the fiber material is 5% to 50%, preferably 15% to 25%.

[0043] As an embodiment of the present invention, the lower flange 331a and the upper flange 331b are made of a metal material and the positioning pin 332 is entirely made of a non-metallic material. In some embodiments, the non-metallic material is ceramic, glass, rigid polyvinyl chloride, polyethylene, plexiglass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK, and / or PPS. Preferably, the non-metallic material contains fibers and / or graphene to enhance the strength of the positioning pin and prevent the positioning pin 332 from being damaged when transmitting torque between the upper pneumatic assembly 32 and the chuck 31, so as to ensure the normal operation of the wafer handling device. Wherein, the fibers may be one or more of glass fibers, carbon fibers, boron fibers, aramid fibers, silicon carbide fibers, asbestos fibers, etc. for enhancing the strength of plastics, and the length of the fibers is 0.2 mm to 12 mm, preferably 1 mm to 5 mm. The positioning pin 332 made of a non-metallic material can prevent metal contaminants from being generated when it contacts the lower flange 331a and the upper flange 331b.

[0044] In the description of the present specification, the descriptions referring to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In the present specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0045] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A driving component for carrying a head, characterized in that, It includes a flange disposed at the bottom of the driving component for connecting the carrier head. The flange has a positioning pin. The main body of the positioning pin is made of a metal material, and a non-metal structure for avoiding wear is provided on part or all of its surface. The non-metal structure covers the outer peripheral edge of the end face of the positioning pin to prevent metal contamination caused by damage to the surface of the flange due to misalignment between the positioning pin and the positioning pin hole.

2. The drive assembly according to claim 1, wherein The non-metal structure is formed as a frustum of a cone. The diameter of the bottom surface of the frustum of the cone combined with the positioning pin is equal to the diameter of the joint surface of the positioning pin, and the diameter of the top surface of the frustum of the cone is less than or equal to the diameter of the positioning pin, so that the positioning pin is convenient to align with the positioning pin hole.

3. A wafer carrier device, comprising a carrier head and an upper pneumatic component. The carrier head is coupled to the upper pneumatic component through a connecting component. The connecting component includes two flanges. The two flanges are respectively disposed at the top of the carrier head and the bottom of the upper pneumatic component. At least one of the flanges is provided with a positioning pin, and the other flange is provided with a positioning pin hole for cooperating with the positioning pin. The main body of the positioning pin is made of a metal material, and a non-metal structure is provided on part or all of its surface. The non-metal structure covers the outer peripheral edge of the end face of the positioning pin to prevent metal contamination caused by damage to the surface of the flange due to misalignment between the positioning pin and the positioning pin hole.

4. The wafer carrier device according to claim 3, wherein, The positioning pin has a partial columnar structure, the end face is circular, and the diameter of the end face is smaller than the diameter of the columnar structure, so that the positioning pin is convenient to align with the positioning pin hole.

5. The wafer carrier device according to claim 4, wherein The non-metal structure is formed as a frustum of a cone, and the lower diameter of the non-metal structure is equal to the diameter of the columnar structure.

6. The wafer carrier device according to any one of claims 3-5, characterized in that, The non-metal structure covers the entire surface disposed on the outer peripheral side of the positioning pin.

7. The wafer carrier device according to any one of claims 3-5, characterized in that, The edges of the non-metal structure are chamfered with arcs.

8. The wafer carrier device according to any one of claims 3-5, characterized in that, There are a plurality of air holes on the two flanges. The positioning pin is inserted into the positioning pin hole so that the air holes on the two flanges are accurately aligned with each other.

9. A chemical mechanical polishing device, characterized in that, It includes a polishing disc, a polishing pad, a dressing device, a polishing liquid supply device, and the wafer carrier device according to any one of claims 3-8. The wafer carrier device is used to hold the wafer and press the wafer against the surface of the polishing pad.

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