A driving assembly for a carrier head and a wafer carrier device

Abstract

The present invention discloses a driving assembly for a carrier head and a wafer carrier device, comprising a carrier head and an upper pneumatic assembly, wherein the carrier head is coupled to the upper pneumatic assembly via a connecting assembly, wherein the connecting assembly comprises a locating pin and a flange with a locating pin hole, wherein the locating pin and the flange are made of metal material, and a non-metallic structure is provided on part or all of the surface of the locating pin so that no metal contaminants are generated when the locating pin contacts the flange.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical mechanical polishing, and in particular, relates to a driving assembly for a carrier head and a wafer carrier device. Background Art

[0002] At present, chemical mechanical polishing (CMP, also known as chemical mechanical planarization) as a technology to achieve global flatness of wafers has developed into equipment that integrates polishing, wafer transfer, online measurement, cleaning and other technologies. Chemical mechanical polishing usually sucks the wafer onto the bottom surface of the carrier head at the bottom of the carrier device, and the side of the wafer with the deposition layer is pressed against the upper surface of the polishing pad. The carrier head rotates in the same direction as the polishing pad under the actuation of the upper pneumatic assembly (UPA) and applies a downward load to the wafer; at the same time, the 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 the chemical mechanical polishing of the wafer under the combined action of chemistry and mechanics.

[0003] Problems encountered in the prior art include that the wafer surface is easily scratched by metal contaminants and / or the metal contaminants exceed the standard during the chemical mechanical polishing process, which are difficult to accept in the field of chip manufacturing, especially as the chip process continues to decline, unprecedented high requirements are placed on the level of metal contamination. Generally speaking, once it is found that the wafer surface is scratched by metal contaminants or the metal contaminants exceed the standard, it may be necessary to replace all related consumables, thereby greatly increasing costs and reducing production efficiency. For example, as pointed out in CN107301960A, in the semiconductor process, metal ion contaminants are called mobile ion contamination sources, which have strong mobility in semiconductor materials, can cause oxide-polysilicon gate structure defects, increase PN junction leakage current, reduce minority carrier lifetime, and change threshold voltage, which have serious harm to the yield and reliability of the device.

[0004] The carrier head of the wafer carrier device is an important part of the chemical mechanical polishing equipment. The carrier head needs to be regularly loaded and unloaded to carry out maintenance operations and replace parts 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 with the connecting piece of the upper pneumatic component through a positioning pin and connected to it through a clamp, and vice versa; the existing positioning pins are easy to scratch the mounting surface of the metal connecting piece during installation, thereby generating metal contaminants such as metal debris, metal particles, and metal particles. Similarly, the connecting piece of the upper pneumatic component can also be equipped with a positioning pin for positioning with the mounting surface of the connecting piece of the carrier head, and the upper positioning pin is also easy to scratch the connecting piece of the carrier head during installation and generate metal contaminants. Summary of the invention

[0005] The present invention aims to solve one of the technical problems existing in the prior art to at least some extent. To this end, the present invention provides a driving assembly for a carrier head, comprising a flange plate arranged at the bottom of the driving assembly for connecting the carrier head, the flange plate having a positioning pin, the main body of the positioning pin being made of a metal material and part or all of its surface being provided with a non-metallic structure to avoid wear.

[0006] According to one aspect of the present invention, the non-metallic structure is provided at an end surface of the locating pin for inserting into a locating pin hole of a carrier head.

[0007] According to one aspect of the present invention, the non-metallic structure is formed as a truncated cone, the diameter of the bottom surface of the truncated cone combined with the positioning pin is equal to the diameter of the combining surface of the positioning pin, and the diameter of the top surface of the truncated cone is less than or equal to the diameter of the positioning pin.

[0008] According to one aspect of the present invention, the non-metallic structure is made of at least one of plastic, ceramic, and glass.

[0009] According to one aspect of the present invention, the plastic is a hard engineering plastic.

[0010] According to one aspect of the present invention, the hard engineering plastic is hard polyvinyl chloride, polyethylene, organic glass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK and / or PPS.

[0011] According to one aspect of the present invention, the non-metal structure is made of composite plastic containing fibers and / or graphene.

[0012] According to one aspect of the present invention, the metal material is a hard metal material that does not contain aluminum.

[0013] Furthermore, the present invention also discloses a wafer carrying device, including a carrying head and an upper pneumatic component, wherein the carrying head is coupled to the upper pneumatic component via a connecting component, wherein the connecting component includes a locating pin and two flanges with locating pin holes, wherein the locating pin is arranged at the bottom of the upper pneumatic component, and the locating pin hole matches the flange arranged at the top of the carrying head; a non-metallic structure is provided on part or all of the surface of the locating pin so that the locating pin and the flange contact each other without causing wear and / or generating metal contaminants.

[0014] Furthermore, the present invention also discloses a wafer carrying device, including a carrying head and an upper pneumatic component, wherein the carrying head is coupled to the upper pneumatic component via a connecting component, wherein the connecting component includes a locating pin and two flanges with locating pin holes, wherein the locating pin is arranged at the bottom of the upper pneumatic component, and the locating pin hole matches the flange arranged at the top of the carrying head; the locating pin is made of non-metallic material.

[0015] The driving assembly of the carrier head and a wafer carrier device described in the present invention have a reasonable structure, and 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 maintenance operations on the carrier device and when the positioning pin contacts the flange, thereby solving the problem that the wafer surface is easily scratched by metal contaminants and / or the metal contaminants exceed the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The advantages of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings, which are only schematic and do not limit the scope of protection of the present invention, wherein:

[0017] Figure 1 is a schematic structural diagram of a chemical mechanical polishing device according to the present invention;

[0018] Figure 2 is a schematic structural diagram of a wafer carrying device according to the present invention;

[0019] Figure 3 is a schematic structural diagram of a carrier head according to the present invention;

[0020] Figure 4 is a schematic structural diagram of an upper pneumatic assembly according to the present invention;

[0021] Figure 5a , 5b 5c is a schematic diagram of the structure of the positioning pin according to the present invention.

[0022] The meanings of the numerical reference symbols are as follows:

[0023] 100-Chemical mechanical polishing device;

[0024] 10- polishing disc;

[0025] 20- polishing pad;

[0026] 30-wafer carrying device; 31-carrying head; 32-upper pneumatic assembly; 33-connecting assembly; 331a-lower flange; 331b-upper flange; 332-positioning pin; 3321a, 3321b, 3321c-non-metallic structure; 333a, 333b-positioning pin hole; 334a, 334b-air hole;

[0027] 40-dressing device; 41-dressing arm; 42-dressing head;

[0028] 50-Polishing liquid supply device. DETAILED DESCRIPTION

[0029] The technical scheme of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0030] The drawings of this specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of various components of 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.

[0031] It should be pointed out that the wafer in the present invention is sometimes also referred to as a "substrate" or "base wafer" in the industry, which have roughly the same meaning and are not distinguished in the CMP field in most cases.

[0032] Figure 1 The chemical mechanical polishing device 100 shown includes a polishing disk 10, a polishing pad 20, a wafer carrier 30, a dressing device 40 and a polishing liquid supply device 50; the polishing pad 20 is arranged on the upper surface of the polishing disk 10 and rotates along the axis Ax1 with the polishing disk 10; the horizontally movable wafer carrier 30 is arranged above the polishing pad 20, and its lower surface holds the wafer W to be polished; 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 achieve a state suitable for polishing; the polishing liquid supply device 50 spreads the polishing liquid on the surface of the polishing pad 20; during the polishing operation, the wafer carrier 30 presses the surface of the wafer W to be polished 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 wafer surface material is completed under the action of chemical machinery.

[0033] like Figure 2As shown, the wafer carrier 30 includes a carrier head 31 and an upper pneumatic assembly 32 (UPA). The carrier head 31 is coupled to the upper pneumatic assembly 32 via a connecting assembly 33. The connecting 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 arranged on the top of the carrier head 31 for connecting to the upper flange 331b at the bottom of the upper pneumatic assembly 32.

[0034] Figure 3 The wafer carrier head 31 of the wafer carrier device 30 according to the present invention is shown, and the lower flange 331a at the top thereof is provided with 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 path of the upper pneumatic assembly 32; Figure 4 The upper pneumatic assembly 32 of the wafer carrier 30 according to the present invention is shown, and the upper flange 331b at the bottom thereof is provided with at least one positioning pin 332, at least one positioning pin hole 333b and a plurality of air holes 334b, and the air holes 334a of the carrier head 31 and the air holes 334b ​​of the upper pneumatic assembly 32 are precisely aligned with each other and are airtightly connected, so that the upper pneumatic assembly 32 can adjust the pressure formula of the carrier head 31 by introducing / exhausting gas into the carrier head 31. As an alternative embodiment, two positioning pins 332 and corresponding positioning pin holes can also be provided only on the upper flange 331b or the lower flange 331a.

[0035] When performing assembly and / or maintenance operations, it is necessary to lift the carrier head 31 so that it can be accurately assembled to the upper pneumatic component 32, so that the locating pin 332 of the carrier head 31 is inserted into the locating pin hole 333b of the upper pneumatic component 32 and / or the locating pin 332 of the upper pneumatic component 32 is inserted into the locating pin hole 333a of the carrier head 31, so as to ensure that the air hole 334a of the carrier head 31 and the air hole 334b ​​of the upper pneumatic component 32 are precisely aligned with each other, and the clamp not shown fastens the lower flange 331a and the upper flange 331b to realize the assembly connection between the carrier head 31 and the upper pneumatic component 32.

[0036] As an embodiment of the present invention, Figure 2 As shown, the main bodies of the lower flange 331a, the upper flange 331b and the positioning pin 332 are made of metal material, and at least one end face of the positioning pin 332 and / or its adjacent portion have a non-metallic structure. Since the hardness of the non-metallic structure is much lower than that of the flange made of metal, the contact between them can prevent the positioning pin 332 from being inserted into the positioning pin holes 333a, 333b in an unaligned manner and damaging the flange surface to produce metal contamination including metal debris and / or metal particles, thereby preventing scratches on the wafer or affecting the yield rate of wafer polishing.

[0037] Figure 5a A variation of the embodiment of the positioning pin 332 according to the present invention is shown, the non-metallic structure 3321a is sleeved on the end of the positioning pin 332, the end of the positioning pin 332 is formed into a truncated cone, and the upper end diameter of the non-metallic structure 3321a is smaller than the lower end diameter, so that the positioning pin 332 is easy to align with the positioning pin holes 333a, 333b and prevent the two from being misaligned and damaging the flange surface to generate metal debris and / or metal particles. As a variation of this embodiment, Figure 5b As shown, the outer end of the assembly formed by the non-metallic structure 3321b and the positioning pin 332 is a columnar structure, and the edges of the columnar structure are chamfered; as a variation of this embodiment, Figure 5c As shown, the non-metallic structure 3321c can also be set only at the circumferential edge of the locating pin 332, that is, the non-metallic structure 3321c only needs to cover the edge of the locating pin 332 to prevent the locating pin 332 from being inserted into the locating pin holes 333a, 333b without being aligned, and the edge of the locating pin 332 made of metal material directly contacts the metal flanges 331a, 331b and generates metal contamination such as metal debris and / or metal particles.

[0038] In view of the need to strictly prevent aluminum ion contamination during the wafer production 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. This can reduce the amount of aluminum ions in the polishing environment and control metal contaminants within the required range.

[0039] As another variation of an embodiment of the present invention, the non-metallic structure may also cover the entire surface of the outer peripheral side of the locating pin 332 or be arranged to cover the entire outer surface of the locating pin 332. When the carrier head 31 is connected and assembled with the upper pneumatic component 32, the setting of the non-metallic structure ensures that no metal contaminants are generated when the locating pin 332 contacts the lower flange 331a and the upper flange 331b.

[0040] As another variation 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. Figure 5a , Figure 5b and Figure 5c The thickness of the non-metallic structure 3321 shown in FIG. 3 is 1.2 mm.

[0041] As another variation of the embodiment of the present invention, the non-metal structure 3321 is made of at least one material selected from 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, organic glass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK, and / or PPS. Figure 5a In the embodiment shown, the non-metallic structure 3321 can be made of PEEK. As one aspect of this embodiment, the non-metallic structure 3321 is made of reinforced composite plastic containing fiber and / or graphene. Under the premise of ensuring that no metal contaminants are generated when the locating pin 332 contacts the lower flange 331a and the upper flange 331b, the fiber and / or graphene can improve the strength of the locating pin 332, prevent the locating pin 332 from being damaged during the torque transmission between the upper pneumatic component 32 and the carrier head 31, and ensure the normal operation of the wafer carrier; wherein the fiber can be one or more of glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, etc. for enhancing the strength of plastic, the length of the fiber is 0.2 mm to 12 mm, preferably 1 mm to 5 mm, and the weight proportion of the fiber material is 5% to 50%, preferably 15% to 25%.

[0042] As an embodiment of the present invention, the lower flange 331a and the upper flange 331b are made of metal materials and the positioning pin 332 is completely made of non-metallic materials. In some embodiments, the non-metallic material is ceramic, glass, rigid polyvinyl chloride, polyethylene, organic glass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK and / or PPS. Preferably, the non-metallic material contains fiber and / or graphene to enhance the strength of the positioning pin, prevent the upper pneumatic component 32 and the carrier head 31 from damaging the positioning pin 332 when transmitting torque, so as to ensure the normal operation of the wafer bearing device, wherein the fiber can be one or more of glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, etc. for enhancing the strength of plastic, and the length of the fiber is 0.2mm to 12mm, preferably 1mm to 5mm. The positioning pin 332 made of non-metallic material can prevent the generation of metal contaminants when it contacts the lower flange 331a and the upper flange 331b.

[0043] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does 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.

[0044] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A drive assembly for a carrier head, characterized in that: It includes a flange plate arranged at the bottom of the driving assembly for connecting the bearing head, the flange plate has a positioning pin, the main body of the positioning pin is made of metal material and part or all of its surface is provided with a non-metallic structure to avoid wear; The metal material is a hard metal material that does not contain aluminum; The non-metal structure is arranged at the end surface of the positioning pin for inserting into the positioning pin hole of the bearing head, and is made of at least one of plastic, ceramic and glass; The non-metallic structure is formed as a truncated cone, the diameter of the bottom surface of the truncated cone combined with the locating pin is equal to the diameter of the joint surface of the locating pin, and the diameter of the top surface of the truncated cone is less than or equal to the diameter of the locating pin, so that the locating pin is easy to align with the locating pin hole and prevent the two from being misaligned to damage the flange surface and produce metal debris and / or metal particles.

2. The drive assembly according to claim 1, characterized in that The plastic is hard engineering plastic.

3. The drive assembly according to claim 2, characterized in that: The hard engineering plastic is hard polyvinyl chloride, polyethylene, organic glass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK and / or PPS.

4. The drive assembly according to claim 1, characterized in that: The non-metal structure is made of composite plastic containing fibers and / or graphene.

5. A wafer carrier device, comprising a carrier head and an upper pneumatic assembly, wherein the carrier head is coupled to the upper pneumatic assembly via a connecting assembly, wherein the connecting assembly comprises a locating pin and two flanges with locating pin holes, wherein the locating pin is arranged at the bottom of the upper pneumatic assembly, and the locating pin holes match the flange arranged at the top of the carrier head; the main body of the locating pin is made of a metal material and a non-metallic structure is arranged on part or all of its surface so that the locating pin and the flange contact each other without causing wear and / or generating metal contaminants; The non-metallic structure is formed as a truncated cone, the diameter of the bottom surface of the truncated cone combined with the locating pin is equal to the diameter of the joint surface of the locating pin, and the diameter of the top surface of the truncated cone is less than or equal to the diameter of the locating pin, so that the locating pin is easy to align with the locating pin hole and prevent the two from being misaligned to damage the flange surface and produce metal debris and / or metal particles.

6. The wafer carrier device according to claim 5, characterized in that: The non-metal structure is made of at least one of plastic, ceramic and glass.

7. The wafer carrier device according to claim 6, characterized in that: The plastic is hard engineering plastic.

8. The wafer carrier device according to claim 7, characterized in that: The hard engineering plastic is hard polyvinyl chloride, polyethylene, organic glass, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET, ABS, PEEK and / or PPS.

9. The wafer carrier device according to claim 5, characterized in that: The non-metal structure is made of composite plastic containing fibers and / or graphene.

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