CN116175402A

CN116175402A - Carrier head assembly for chemical mechanical polishing and chemical mechanical polishing apparatus

Info

Publication number: CN116175402A
Application number: CN202310413446.6A
Authority: CN
Inventors: 马旭; 刘远航; 靳凯强; 路新春; 赵德文
Original assignee: Huahaiqingke Co Ltd
Current assignee: Huahaiqingke Co Ltd
Priority date: 2023-04-18
Filing date: 2023-04-18
Publication date: 2023-05-30

Abstract

The invention discloses a bearing head assembly for chemical mechanical polishing and chemical mechanical polishing equipment, wherein the bearing head assembly comprises a main shaft flange and a bearing head flange which are connected with each other, and a positioning structure is arranged between the main shaft flange and the bearing head flange and used for enabling all positions to correspond when being assembled; and the bottom of the main shaft flange and/or the top of the bearing head flange are/is provided with a magnetic structure for auxiliary installation. The invention can greatly reduce the difficulty of maintenance of the bearing head, improve the installation efficiency, reduce the operation threshold and reduce the maintenance cost.

Description

Carrier head assembly for chemical mechanical polishing and chemical mechanical polishing apparatus

Technical Field

The invention relates to the technical field of chemical mechanical polishing, in particular to a bearing head assembly for chemical mechanical polishing and chemical mechanical polishing equipment.

Background

Chemical mechanical polishing (CMP, chemical Mechanical Polishing) is a very important element in the wafer fabrication process. The polishing process is to press the wafer against the surface of the polishing pad by the carrier head, and the wafer surface polishing is realized by the relative motion between the wafer and the polishing pad and by the abrasive particles in the polishing liquid.

In the production process, the carrying head is required to be assembled and disassembled regularly, parts are replaced and the like so as to carry out maintenance operation and ensure the service life of the carrying head. When the maintenance of the bearing head is carried out, the flange of the bearing head can fall down due to the dead weight, and the flange of the bearing head is generally required to be manually supported, so that the upper flange and the lower flange are kept in a tightly-attached state all the time to finish fixation. Because the dead weight of the bearing head flange is large, the bearing head flange can be supported by using large force, the connection of the two flange faces is difficult, and two operators are generally required to finish the connection, so that the difficulty and time consumption of the maintenance process are greatly increased.

Disclosure of Invention

The embodiment of the invention provides a bearing head assembly for chemical mechanical polishing and chemical mechanical polishing equipment, which aim to at least solve one of the technical problems in the prior art.

A first aspect of an embodiment of the present invention provides a carrier head assembly for chemical mechanical polishing, including a spindle flange and a carrier head flange that are used for being connected to each other, a positioning structure being provided between the spindle flange and the carrier head flange, for enabling positions of the spindle flange and the carrier head flange to correspond to each other during assembly; and the bottom of the main shaft flange and/or the top of the bearing head flange are/is provided with a magnetic structure for auxiliary installation.

In one embodiment, the magnetically attractable structure is an embedded magnet formed of a neodymium magnet, a samarium cobalt magnet, an alnico magnet, or a ferrite magnet.

In one embodiment, the bottom of the main shaft flange is provided with a magnetic attraction structure, and the material of the top of the bearing head flange is a ferromagnetic material.

In one embodiment, the top of the bearing head flange is provided with a magnetic attraction structure, and the material at the bottom of the main shaft flange is a ferromagnetic material.

In one embodiment, the bottom of the spindle flange is provided with a first magnetic attraction structure, the top of the bearing head flange is provided with a second magnetic attraction structure, and the polarities of the magnetic poles of the relative positions of the first magnetic attraction structure and the second magnetic attraction structure are opposite.

In one embodiment, the locating structure comprises a locating pin provided at the bottom of the spindle flange and/or at the top of the carrier head flange.

In one embodiment, an auxiliary disassembly structure is provided between the spindle flange and the carrier head flange.

In one embodiment, the auxiliary dismounting structure is a V-shaped groove arranged on the bottom surface edge of the main shaft flange and/or the top surface edge of the bearing head flange.

In one embodiment, the magnetic attraction structure does not extend beyond the surfaces of the spindle flange and the carrier head flange.

A second aspect of an embodiment of the present invention provides a chemical mechanical polishing apparatus including a carrier head, a carrier head assembly as described above for connecting the carrier head, and further including a polishing platen, a conditioner, and a polishing liquid supply device.

The beneficial effects of the embodiment of the invention include: the difficulty of bearing head maintenance can be greatly reduced, the installation efficiency is improved, the operation threshold is reduced, and the maintenance cost is reduced.

Drawings

The advantages of the present invention will become more apparent and more readily appreciated from the detailed description given in conjunction with the following drawings, which are meant to be illustrative only and not limiting of the scope of the invention, wherein:

FIG. 1 illustrates a chemical mechanical polishing apparatus provided in accordance with one embodiment of the present invention;

FIG. 2 illustrates an installation process for a carrier head assembly provided in accordance with one embodiment of the present invention;

FIG. 3 illustrates a spindle flange and carrier head flange provided in accordance with one embodiment of the present invention;

fig. 4 shows a spindle flange and carrier head flange provided by a further embodiment of the invention.

Detailed Description

The following describes the technical scheme of the present invention in detail with reference to specific embodiments and drawings thereof. The examples described herein are specific embodiments of the present invention for illustrating the concept of the present invention; the description is intended to be illustrative and exemplary in nature and should not be construed as limiting the scope of the invention in its aspects. It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. In addition to the embodiments described herein, those skilled in the art can adopt other obvious solutions based on the disclosure of the claims of the present application and the specification thereof, including those adopting any obvious substitutions and modifications to the embodiments described herein. It should be understood that the following description of the embodiments of the present invention, unless specifically stated otherwise, is established in the natural state of the relevant devices, apparatuses, components, etc. in which no external control signal or driving force is given, in order to facilitate understanding.

Furthermore, it is noted that terms such as front, back, upper, lower, left, right, top, bottom, front, back, horizontal, vertical, and the like used herein are merely used for ease of description to aid in understanding the relative position or orientation and are not intended to limit the orientation of any apparatus or structure.

In order to describe the technical solution according to the invention, reference will be made to the accompanying drawings and examples.

In this application, chemical mechanical polishing (Chemical Mechanical Polishing) is also referred to as chemical mechanical planarization (Chemical Mechanical Planarization), and wafers are also referred to as wafers, silicon chips, substrates or substrates (substrates), etc., and their meaning and actual function are equivalent.

As shown in fig. 1, a chemical mechanical polishing apparatus 1 according to an embodiment of the present invention includes a polishing platen 10, a polishing pad 20 bonded to the polishing platen 10, a carrier head 30 that adsorbs a wafer and rotates the wafer, a dresser 40 that dresses the polishing pad 20, and a polishing liquid supply device 50 that supplies a polishing liquid to a surface of the polishing pad 20.

Before polishing starts, the robot hand carries the wafer to the wafer storage section, and the carrier head 30 moves from the wafer storage section to above the polishing platen 10 in the radial direction of the polishing platen 10 after loading the wafer. During chemical mechanical polishing, the carrier head 30 presses the wafer against the polishing pad 20 covered by the surface of the polishing platen 10, and the size of the polishing pad 20 is larger than the size of the wafer to be polished, for example, 1.2 times the size of the wafer or more, thereby ensuring uniform polishing of the wafer. The carrier head 30 is rotated and reciprocated in the radial direction of the polishing pad 10 so that the surface of the wafer in contact with the polishing pad 20 is gradually polished while the polishing pad 10 is rotated, and the polishing liquid supply apparatus 50 sprays the polishing liquid to the surface of the polishing pad 20. The wafer is rubbed against the polishing pad 20 by the relative motion of the carrier head 30 and the polishing platen 10 under the chemical action of the polishing liquid to perform polishing. The polishing solution composed of submicron or nanometer abrasive particles and chemical solution flows between the wafer and the polishing pad 20, the polishing solution is uniformly distributed under the action of the transmission and rotation centrifugal force of the polishing pad 20 to form a layer of liquid film between the wafer and the polishing pad 20, chemical components in the liquid react with the wafer to convert insoluble substances into soluble substances, then the chemical reactants are removed from the surface of the wafer through the micro-mechanical friction of the abrasive particles and dissolved into the flowing liquid to be taken away, namely, surface materials are removed in the alternating process of chemical film formation and mechanical film removal to realize surface planarization treatment, so that the aim of global planarization is achieved. The conditioner 40 is used to condition and activate the surface topography of the polishing pad 20 during polishing. The use of the dresser 40 can remove impurity particles remaining on the surface of the polishing pad 20, such as abrasive particles in the polishing liquid, and waste material that falls off from the wafer surface, and can planarize the deformation of the surface of the polishing pad 20 due to the polishing, ensuring the uniformity of the surface topography of the polishing pad 20 during polishing, and further maintaining a stable polishing removal rate. After polishing is completed, the carrier head 30 adsorbs the wafer to place it on the wafer storage section, and the robot hand takes the wafer from the wafer storage section and conveys the wafer to the post-processing unit.

The carrier head 30 for chemical mechanical polishing includes a coupling plate, a gimbal, a carrier plate, a flexible membrane, and a retaining ring.

The balance frame is slidably arranged in the central through hole of the connecting disc roller, the bottom of the balance frame drives the bearing disc to move up and down relative to the connecting disc roller, and a part of the flexible film is clamped to the lower part of the bearing disc to form a sealing cavity; the retaining ring is mounted at the bottom edge of the carrier plate.

The first clamping ring clamps and bonds the outer edge of the annular elastic piece to the bearing disc and the second clamping ring clamps and bonds the inner edge of the annular elastic piece to the coupling disc roller, so that the coupling disc roller can drive the bearing disc to coaxially rotate together through the annular elastic piece when the coupling disc roller rotates together with the external driving shaft; the third clamping ring and the annular gasket clamp and fix the balance frame to the bearing disc, and the annular pressure plate clamps the flexible film to the lower part of the bearing disc in an airtight manner so that the flexible film can coaxially rotate together with the bearing disc and the balance frame and vertically move up and down relative to the roller of the connecting disc; the retaining ring is attached to the lower surface of the carrier plate. When the carrier head is in operation, the capstan roller is coupled to an external drive shaft and the wafer to be processed is received and held under the flexible membrane inside the retaining ring.

The retaining ring is mounted to the lower portion of the carrier head 30. During chemical mechanical polishing, a receiving space is formed between the inner diameter surface of the retaining ring and the lower surface of the flexible membrane for defining the wafer. The bottom surface of the retaining ring faces downwards and is opposite to the upper surface of the polishing pad, the wafer positioned inside the retaining ring is pressed against the upper surface of the polishing pad, and the retaining ring can prevent the wafer from sliding out of the accommodating space and participating in the load application of the wafer. Additionally, the carrier platter may be raised and lowered to control the pressure exerted by the bottom surface of the retaining ring on the polishing pad. As shown in fig. 2, the bottom surface of the retainer ring is provided with channels for the inflow and outflow of the polishing liquid. The retaining ring is coupled with the carrier plate, and is mounted on the lower portion of the carrier head 30 through the carrier plate.

The carrier head 30 provided in the embodiment of the present invention is connected to an upper driving device through a carrier head assembly, and the upper driving device is used for providing pneumatic control and driving control for the carrier head 30, so as to implement various actions of the carrier head 30.

As shown in fig. 2 to 4, an embodiment of the present invention provides a carrier head assembly for chemical mechanical polishing, which includes a spindle flange 31, a carrier head flange 32 and a clamp 33 that are connected to each other, wherein a positioning structure is disposed between the spindle flange 31 and the carrier head flange 32, so that the positions of the spindle flange 31 and the carrier head flange 32 correspond to each other during assembly; the bottom of the spindle flange 31 and/or the top of the carrier head flange 32 are provided with magnetic attraction structures for auxiliary mounting. The magnetic attraction structure can be an embedded magnet, and the magnet is formed by a neodymium magnet, a samarium cobalt magnet, an alnico magnet or a ferrite magnet.

The carrier flange 32 is located at the top of the carrier 30 and is fixedly connected to the main structure of the carrier 30, and the spindle flange 31 is connected to the bottom of the spindle of the upper driving device. The spindle flange 31 and the carrier head flange 32 are detachably connected.

As shown in fig. 3 and 4, the locating structure includes locating pins provided on the bottom of the spindle flange 31 and/or the top of the carrier head flange 32. The positioning structure comprises at least two pairs of positioning pins and positioning holes, the positioning pins are respectively arranged on opposite surfaces of the bearing head flange 32 and the main shaft flange 31, and the positioning pins are inserted into the positioning holes to realize positioning during assembly. And the positioning structure enables maintaining alignment between the carrier head 30 and the spindle to avoid misalignment when a shearing force in the horizontal direction acts on the carrier head 30 during polishing.

Specifically, the bottom surface of the spindle flange 31 is provided with at least one positioning pin 311, at least one positioning hole 312, and a plurality of air holes 313 for communicating with the air path of the upper driving device. Accordingly, the top surface of the carrier head flange 32 is provided with positioning pins 321 corresponding to the number of positioning holes 312 of the spindle flange 31, positioning holes 322 corresponding to the number of positioning pins 311 of the spindle flange 31, and air holes 323 corresponding to the number of air holes 313 of the spindle flange 31. Further, a seal ring is provided around the periphery of the air hole 323 of the carrier head flange 32. The air holes 323 of the carrier head flange 32 are precisely aligned and air-tightly connected with the air holes 313 of the spindle flange 31, respectively, so that the upper driving device can be used for introducing or exhausting air into the carrier head 30 through the air holes to adjust the polishing pressure applied to the wafer by the carrier head 30.

When the assembly or maintenance work is performed, the carrier head 30 is lifted to make the carrier head flange 32 at the top and the spindle flange 31 fixed to the upper driving device, in order to achieve the accurate alignment of the carrier head flange 32 and the spindle flange 31 to complete the assembly, the positioning pins 321 of the carrier head flange 32 are inserted into the positioning holes 312 of the spindle flange 31 or/and the positioning pins 311 of the spindle flange 31 are inserted into the positioning holes 322 of the carrier head flange 32, so that the air holes 323 of the carrier head flange 32 and the air holes 313 of the spindle flange 31 are ensured to be accurately aligned with each other, and then the carrier head flange 32 and the spindle flange 31 are fastened by the clamp 33.

In order to facilitate lifting of the carrier head 30, as shown in fig. 3 and 4, in the embodiment of the present invention, a magnetic structure is disposed at the connection between the spindle flange 31 and the carrier head flange 32 for auxiliary fixation. In order to ensure the flatness of the contact surface between the spindle flange 31 and the carrier head flange 32, the magnetic attraction structure does not exceed the surfaces of the spindle flange 31 and the carrier head flange 32, and is only an embedded structure.

The magnetic attraction structure is a magnet embedded in the spindle flange 31 or the carrier head flange 32, and the magnet can be made of metal or ceramic materials. Such materials may include iron or rare earth metals such as neodymium, neodymium iron boron, samarium cobalt, alnico, and magnets in the ceramic family, with ceramics such as hard magnet oxides, strontium, and barium ferrites. The magnets may be permanent magnets, for example formed from neodymium magnets, samarium cobalt magnets, alnico magnets or ferrite magnets. Alternatively, the magnets may be electromagnetic.

As shown in fig. 3 and 4, in one embodiment, the magnetic attraction structure is provided with a plurality of magnetic attraction structures, at least one of which is located at the center of the bottom surface of the main shaft flange or the top surface of the bearing head flange, and the rest of the magnetic attraction structures are evenly distributed around the air hole and located at the periphery of the air hole so as to realize better attraction.

In another embodiment, an annular magnetic attraction structure can be further arranged, and the annular magnetic attraction structure is arranged around the air hole at the periphery of the air hole.

The magnetic structure is embedded into the main shaft flange or the bearing head flange no matter what shape, and only the surface is exposed and is flush with the surface of the air hole.

As shown in fig. 3, in one embodiment, the bottom of the spindle flange 31 is embedded with a magnetic attraction structure 314, and the material on the top of the carrier head flange 32 is a ferromagnetic material. In this embodiment, the magnetic attraction structure 314 may be cylindrical or rectangular, and may be provided with a plurality of magnetic attraction structures uniformly distributed. Alternatively, the magnetic attraction structure 314 may be annular and disposed along the circumferential direction of the bottom surface of the spindle flange 31. The material of the spindle flange 31 may be conventional stainless steel. The carrier head flange 32 may be made of a ferromagnetic material such as iron, nickel or such alloys, or a martensitic, ferritic stainless steel such as 400 series stainless steel that is capable of engaging the spindle flange 31.

It will be appreciated that in another embodiment, the top of the carrier head flange 32 is provided with a magnetic attraction structure, and the material at the bottom of the spindle flange 31 is a ferromagnetic material. In this embodiment, the magnetic attraction structure may be cylindrical or rectangular, and may be provided with a plurality of uniformly distributed magnets. Alternatively, the magnetic attraction structure may be annular and disposed along the circumference of the top surface of the carrier head flange 32. The material of the carrier head flange 32 may be conventional stainless steel. The spindle flange 31 uses a ferromagnetic material.

In yet another embodiment, as shown in fig. 4, a first magnetic attraction structure 315 is provided at the bottom of the spindle flange 31, and a second magnetic attraction structure 324 is provided at the top of the carrier head flange 32, where the magnetic poles of the relative positions of the first magnetic attraction structure 315 and the second magnetic attraction structure 324 are opposite in polarity. In this embodiment, the spindle flange 31 and the carrier head flange 32 are both provided with a magnetic attraction structure. The downward magnetic pole of the first magnetic attraction structure 315 of the spindle flange 31 is opposite to the upward magnetic pole of the second magnetic attraction structure 324 of the carrier head flange 32, thereby achieving attraction with each other. For example, the first magnetic structure 315 exposes an S pole, and the second magnetic structure 324 exposes an N pole.

Further, in one embodiment, an auxiliary disassembly feature is provided between the spindle flange 31 and the carrier head flange 32 to assist in separating the spindle flange 31 from the carrier head flange 32.

The auxiliary dismounting structure is a V-shaped groove arranged on the bottom surface edge of the main shaft flange 31 and/or the top surface edge of the bearing head flange 32. Specifically, a V-shaped groove may be disposed at the bottom edge of the main shaft flange 31, so as to form a gap between the main shaft flange 31 and the carrier head flange 32, so that a tool can be used to extend into the V-shaped groove during disassembly, and the carrier head 30 can be pried open, thereby facilitating the disassembly. Similarly, V-grooves may be provided in the top edge of carrier head flange 32.

Fig. 2 shows the mounting process of the carrier head 30, specifically including:

1) The carrier head 30 is lifted to a position where the carrier head flange 32 is adjacent to the spindle flange 31.

2) Under the action of the magnetic force of the magnetic attraction structure, the bearing head flange 32 is attached to the main shaft flange 31 and is not separated.

3) The carrier head flange 32 and the spindle flange 31 are locked by the clamp 33, thereby realizing the fixed installation of the carrier head 30.

The drawings in the present specification are schematic views, which assist in explaining the concept of the present invention, and schematically show the shapes of the respective parts and their interrelationships. It should be understood that for the purpose of clearly showing the structure of various parts of embodiments of the present invention, the drawings are not drawn to the same scale and like reference numerals are used to designate like parts in the drawings.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. The bearing head assembly for chemical mechanical polishing is characterized by comprising a main shaft flange and a bearing head flange which are connected with each other, wherein a positioning structure is arranged between the main shaft flange and the bearing head flange and used for enabling all positions to correspond when the bearing head assembly is assembled; and the bottom of the main shaft flange and/or the top of the bearing head flange are/is provided with a magnetic structure for auxiliary installation.

2. The carrier head assembly of claim 1, wherein the magnetically attractable structure is an embedded magnet formed of a neodymium magnet, a samarium cobalt magnet, an alnico magnet, or a ferrite magnet.

3. The carrier head assembly of claim 1, wherein the bottom of the spindle flange is provided with a magnetic attraction structure, and the top of the carrier head flange is made of a ferromagnetic material.

4. The carrier head assembly of claim 1, wherein the top of the carrier head flange is provided with a magnetic attraction structure, and the material at the bottom of the spindle flange is a ferromagnetic material.

5. The carrier head assembly of claim 1, wherein the bottom of the spindle flange has a first magnetic attraction structure and the top of the carrier head flange has a second magnetic attraction structure, the poles of the first and second magnetic attraction structures being opposite in polarity.

6. The carrier head assembly of claim 1, wherein the locating structure comprises locating pins provided on a bottom of the spindle flange and/or a top of the carrier head flange.

7. The carrier head assembly of claim 1, wherein an auxiliary disassembly structure is provided between the spindle flange and the carrier head flange.

8. The carrier head assembly of claim 7, wherein the auxiliary disassembly feature is a V-groove provided in a bottom edge of the spindle flange and/or a top edge of the carrier head flange.

9. The carrier head assembly of claim 1, wherein the magnetic attraction structure does not extend beyond the surfaces of the spindle flange and the carrier head flange.

10. A chemical mechanical polishing apparatus comprising a carrier head and a carrier head assembly according to any one of claims 1 to 9 for connection to the carrier head, further comprising a polishing platen, a conditioner and a polishing liquid supply means.