CN112108994A - Bearing head for chemical mechanical polishing and chemical mechanical polishing equipment - Google Patents

Abstract

The invention relates to the technical field of chemical mechanical polishing post-treatment, and discloses a bearing head for chemical mechanical polishing, which comprises a coupling disc, a balance frame, a bearing disc, a flexible membrane and an annular pressure disc, wherein a middle shaft part of the balance frame is slidably arranged in a central through hole of the coupling disc and drives the bearing disc to move up and down relative to the coupling disc through a bottom disc part and a flange part of the balance frame, one part of the flexible membrane is clamped to the lower part of the bearing disc by the annular pressure disc to form a pressure-adjustable chamber, and one part of the balance frame is made of a non-metallic material.

Description

Bearing head for chemical mechanical polishing and chemical mechanical polishing equipment

Technical Field

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

Background

Chemical mechanical polishing is a mainstream method for polishing substrates in the field of chip manufacturing. The polishing method generally attracts and holds the substrate at the lower part of the carrier head, one surface of the substrate with a deposition layer abuts against the rotating polishing pad, and the carrier head rotates in the same direction with the polishing pad under the driving of the driving part and gives a downward load to the substrate; meanwhile, the polishing solution is supplied to the upper surface of the polishing pad and distributed between the substrate and the polishing pad, so that the substrate is subjected to global polishing under the combined action of chemistry and machinery.

The carrier head is an important component of the chemical mechanical polishing apparatus, and the operation performance of the carrier head is directly related to the chemical mechanical polishing effect of the substrate. For example, US20130065495a1 discloses a carrier head, which comprises a carrier tray and an elastic membrane, wherein the elastic membrane is detachably arranged at the lower part of the carrier tray; the carrier tray includes a first portion and a second portion, the first portion being movably disposed concentrically within an upper recess of the second portion such that the first portion and the second portion are movable relative to each other in a direction perpendicular to a bottom surface of the carrier tray. An elastic membrane is arranged at the lower part of the second part, so that a plurality of air cavities are formed between the second part and the elastic membrane, and the pressure profile of the substrate can be adjusted by adjusting the pressure of each independent air cavity. In the prior art, external air enters the channel inside the first part through the air holes on the upper surface of the first part and flows out from the air holes on the side wall of the first part, and then is conveyed to the air holes on the upper surface of the second part which are respectively communicated with the independent air cavities through the air pipes.

Chinese patent CN104854680B discloses a carrier head which can clamp the tail end of each baffle between clamping plates. The various cleats may be substantially pure plastic, such as polyetheretherketone or polyphenylene sulfide, composite plastic, such as glass-filled or glass-filled PEEK, or metal, such as stainless steel or aluminum. The gimbal mechanism allows the base assembly to slide vertically relative to the housing while limiting lateral movement of the base assembly. The cover is made of, for example, a semi-crystalline thermoplastic polyester based on polyethylene terephthalate, for example polyester, which can be coated on the outside of the base assembly to prevent contamination from the slurry from reaching the interior of the carrier head.

However, as the feature size of electronic devices continues to shrink, the process requirements for Chemical Mechanical Polishing (CMP) are becoming higher and higher during the fabrication process, resulting in more and more gas chamber partitions in the carrier head. The structure of the bearing head is gradually complicated, the number and the combination relation of parts reach the unprecedented complexity, the challenges are brought to the assembly operation and the maintenance operation, and the high precision requirement and the cost requirement are provided for the part processing; in addition, the detection accuracy requirement of the chemical mechanical polishing end point detection is also improved along with the continuous reduction of the size of the characteristic structure, so a certain requirement is also put forward on the whole electromagnetic signal reflection performance of the bearing head, and the electromagnetic measurement signals are hopefully reflected by other metal parts on the bearing head as few as possible when the characteristic thickness of the metal structure on the substrate is measured; moreover, the carrier head is required to rapidly pick and place the substrate and reduce the possible influence on the substrate in the process of pressurizing the substrate, so as to prevent the substrate from being damaged.

In summary, it is desirable to provide a polishing apparatus having more precision and uniformity to achieve more precise and uniform chemical mechanical polishing.

Disclosure of Invention

The embodiment of the invention provides a bearing head for chemical mechanical polishing and chemical mechanical polishing equipment, and aims to solve at least one technical problem in the prior art to a certain extent.

The invention provides a bearing head for chemical mechanical polishing, which comprises a coupling disc, a balance frame, a bearing disc, a flexible membrane and an annular pressure disc, wherein a middle shaft part of the balance frame is slidably arranged in a central through hole of the coupling disc and drives the bearing disc to move up and down relative to the coupling disc through a bottom disc part and a flange part of the balance frame, a part of the flexible membrane is clamped to the lower part of the bearing disc by the annular pressure disc to form a pressure-adjustable chamber, and a part of the balance frame is made of non-metallic materials.

Preferably, the middle shaft part is composed of a middle shaft core and a middle shaft sleeve, the middle shaft sleeve is provided with a connecting hole used for being combined with the middle shaft core, and the inner surface of the connecting hole of the middle shaft sleeve is tightly and fixedly combined with the outer surface of the middle shaft core, so that the balance frame can be driven to move through the middle shaft sleeve.

Preferably, the middle bushing is made of a metal material.

Preferably, the metal material is a metal material having a relative permeability of austenitic stainless steel or less.

Preferably, the metal material is titanium, a titanium alloy, an aluminum alloy, a magnesium alloy, or austenitic stainless steel.

Preferably, the non-metallic material is at least one of PPS plastic, PEEK plastic, PET plastic, POM plastic, ceramic material, or semiconductor material.

Preferably, the center bushing has a top portion covering the center core.

Preferably, the diameter of the top portion is the same as the outer diameter of the middle boss.

Preferably, the top portion extends vertically upwardly along the axis of rotation of the gimbal.

Preferably, the aspect ratio of the central axis core is 2 to 6.

Preferably, the aspect ratio of the central axis core is 3 to 5.

Preferably, the central shaft portion of the balance frame has a fluid passage extending therethrough along a central axis of rotation thereof for delivering fluid into the carrier head.

A second aspect of embodiments of the present invention provides a chemical mechanical polishing apparatus including the carrier head described above.

The application a carrier head and chemical mechanical polishing equipment for chemical mechanical polishing, its beneficial effect includes: the accuracy of film thickness measurement in the polishing process is improved and promoted on the premise of not influencing the operation function and reliability of the bearing head and the chemical mechanical polishing equipment, so that the accuracy of polishing process control and polishing results is promoted, and the like.

Drawings

The advantages of the invention will become clearer and more readily appreciated from the detailed description given with reference to the following drawings, which are given by way of illustration only and do not limit the scope of protection of the invention, wherein:

FIG. 1 is a schematic structural view of a carrier head 1 for chemical mechanical polishing according to the present invention;

FIG. 2 is a schematic view of the structure of the balance 11 according to the present invention;

FIG. 3 is a schematic structural view of the coupling disk 12 according to the present invention;

FIG. 4 is a schematic structural diagram of a carrier tray 13 according to the present invention;

FIG. 5 is a schematic diagram of the construction of a flexible membrane 14 according to the present invention;

FIG. 6 shows a schematic diagram including a film thickness measuring device 203 for measuring the thickness of a metal film layer 202 on a substrate 201 and a carrier head 1 according to the present invention;

FIG. 7 is a schematic view of the mounting of a gimbal with a wave-damping layer in a carrier head 1;

FIG. 8 is a schematic structural diagram of another embodiment of a gimbal according to the present invention.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the following embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention for the purpose of illustrating the concepts of the invention; the description is intended to be illustrative and exemplary and should not be taken to limit the scope of the invention. In addition to the embodiments described herein, those skilled in the art will be able to employ other technical solutions which are obvious based on the disclosure of the claims and the specification thereof, and these technical solutions include technical solutions which make any obvious replacement or modification of the embodiments described herein. It should be understood that, unless otherwise specified, the following description of the embodiments of the present invention is made for the convenience of understanding, and the description is made in a natural state where relevant devices, apparatuses, components, etc. are originally at rest and no external control signals and driving forces are given.

One embodiment of a carrier head 1 for chemical mechanical polishing according to the present invention is shown in fig. 1, and includes a balance 11, a coupling disk 12, a carrier disk 13, a flexible membrane 14, and an annular platen 15; the first clamp ring 20 clamp-couples the outer edge of the annular elastic membrane 21 to the carrier disc 13 and the second clamp ring 23 clamp-couples the inner edge of the annular elastic membrane 21 to the coupling disc 12 so that the coupling disc 12 can bring the carrier disc 13 to coaxially rotate together via the annular elastic membrane 21 when the coupling disc 12 rotates together with an external drive shaft (not shown); the third clamping ring 18 and the annular gaskets 17A, 17B clamp the balance frame 11 to the carrier plate 13, and the annular pressure plate 15 hermetically clamps the flexible membrane 14 to the lower part of the carrier plate 13 so that the flexible membrane 14 can coaxially rotate with the carrier plate 13 and the balance frame 11 and move up and down in the vertical direction relative to the coupling plate 12; the retaining ring 16 is fixedly coupled to the lower surface of the carrier plate 13; when the carrier head 1 is in operation, the coupling disc 12 is coupled to an external drive shaft, and the substrate to be processed is received and held under the flexible membrane 14 inside the retaining ring 16.

As shown in fig. 2, the balance frame 11 is composed of a middle shaft portion 111, a bottom plate portion 112, a peripheral wall portion 113 and a flange portion 114 which extend vertically, the disk-shaped bottom plate portion 112 is formed coaxially at the bottom of the middle shaft portion 111 and has a radius at least 3 times of the radius of the middle shaft portion 111, the peripheral wall portion 113 extends substantially vertically upward along the circumferential edge of the bottom plate portion 112 to not more than half the height of the middle shaft portion 111 to form a semi-closed annular cylindrical stroke chamber 116 having a certain height, and the annular flat flange portion 114 is formed extending horizontally outward from the upper outer surface of the peripheral wall portion 113 and has a thickness equal to or greater than the thickness of the bottom plate portion 112 and/or the peripheral wall portion 113. In addition, the middle shaft portion 111 has a first through hole 115 disposed along an axis thereof and extending from an upper surface of the middle shaft portion 111 to a lower surface of the chassis portion 112, and an external gas source, not shown, may supply gas into the carrier head 1 or extract gas from the carrier head 1 via the first through hole 115 to adjust a pressure of a chamber in the carrier head 1.

As shown in fig. 3, the coupling disk 12 is composed of a cylindrical main body portion 121 and a peripheral portion 122, the main body portion 121 has a second through hole 123 extending therethrough along the central rotational axis thereof to serve as a shaft hole, and at least one third through hole 124 extending in parallel with the second through hole 123, as can be seen from fig. 3, the second through hole 123 is provided extending therethrough along the central rotational axis of the coupling disk 12, and the second through hole 123 is a central through hole. The outer diameter of the body portion 121 is slightly smaller than the inner diameter of the cylindrical stroke chamber 116 so that the body portion 121 of the coupling disc 12 can be inserted downward into the cylindrical stroke chamber 116 of the balance frame 11 when the coupling disc 12 moves downward relative to the balance frame 11 as shown in fig. 1, and the inner diameter of the second through hole 123 matches the outer diameter of the middle shaft portion 111 of the balance frame 11 so that the middle shaft portion 111 can be slidably inserted into the second through hole 123 and airtightly slide therein in the vertical direction; in other words, the gimbal 11 is vertically movable up and down along the common central rotational axis thereof with each other via the second through hole 123 in which the shaft portion 111 and the coupling disk 12 are fitted to each other.

As shown in fig. 4, the carrier plate 13 is a circular plate with a certain thickness, and has a step hole 131 extending through along the central rotation axis, and the step hole 131 is composed of a first step hole 131A, a second step hole 131B, a third step hole 131C, and a fourth step hole 131D, wherein the 4 step holes have different radii and increase from bottom to top. The inner diameter of the first step hole 131A is slightly larger than the outer diameter of the base plate portion 112 of the gimbal 11, the radius of the second step hole 131B is slightly larger than the distance from the central rotation axis to the outer end of the flange portion 114, and the inner diameter of the fourth step hole 131D is 1 to 20mm larger than the outer diameter of the peripheral portion 122 of the coupling disc 12, so that, as shown in fig. 1, the gimbal 11 is clamped and fixed into the step hole 131 by the annular washers 17A, 17B and the third clamp ring 18 to form a relatively closed variable-volume first pressure chamber 25 constituted by the inner surface of the cylindrical stroke chamber 116, the inner surface and the upper surface of the third clamp ring 18, the bottom surface and the side surface of the fourth step hole 131D, the lower surface of the annular elastic membrane 21, the lower surface and the outer surface of the second clamp ring 23, and the lower surface of the coupling disc 12 which is not covered by the second clamp ring.

When gas is introduced into the first pressure chamber 25 through the third through-hole 124, as shown in fig. 1, the gas pressure in the first pressure chamber 25 increases so that the integrated balance 11 and carrier plate 13 integrally move downward in the vertical direction with respect to the coupling plate 12, and the volume of the first pressure chamber 25 increases accordingly; similarly, when gas is drawn out of the first pressure chamber 25 through the third through hole 124, the gas pressure in the first pressure chamber 25 is decreased so that the combined balance frame 11 and carrier plate 13 integrally moves upward in the vertical direction with respect to the coupling plate 12, the volume of the first pressure chamber 25 is correspondingly decreased, and the vertical movement of the balance frame 11 and carrier plate 13 brings the movement of the flexible film 14 and the annular platen 15 to actuate and/or hold the substrate.

Further, as shown in fig. 1, the lower edge of the peripheral portion 122 of the coupling disc 12 has an edge recess 231 for receiving the second clip ring 23, and the depth of the edge recess 231 is configured such that when the second clip ring 23 and the third clip ring 18 are fixed to the coupling disc 12 and the carrier disc 13 via fixing members such as bolts (not shown), respectively, the lower surface of the second clip ring 23 may be flush with or lower than the lower surface of the peripheral portion 122 of the coupling disc 12 and the upper surface of the third clip ring 18 is configured to be flush with or higher than the top surface of the carrier disc 13. Further, the thickness of the third clip 18 in the vertical direction is greater than the depth of the fourth step hole 131D of the step hole 131, the thickness of the second clip 23 in the vertical direction is greater than the depth of the edge recess 231 of the peripheral portion 122 of the stub plate 12, and the height difference h1 between the thickness of the third clip 18 and the depth of the fourth step hole 131D should be greater than the height difference h2 between the thickness of the second clip 23 and the depth of the edge recess 231, so that the third clip 18 can block the stub plate 12 from continuing to move downward by supporting the lower surface of the peripheral portion 122 of the stub plate 12 when the stub plate 12 moves downward to the lowermost position with respect to the balance frame 11 to provide a limit function.

The flexible membrane 14 functions to cooperate with the rest of the carrier head 1 to form at least two pressure-adjustable gas chambers to further fine tune the pressure profile applied to the substrate to improve the uniformity and consistency of the chemical mechanical polishing. To this end, as shown in fig. 5, the flexible film 14 is formed to be constituted by a circular bottom plate portion 141, an annular edge bellows 142, and at least one annular inner bellows 143, the edge bellows 142 vertically extends upward along the circumferential edge of the circular bottom plate portion 141 and horizontally extends toward the radially inner side at the tip end thereof for a distance to form an annular first horizontal extending portion 144, and the first horizontal extending portion 144 has an annular first sealing projection 145 at the inner edge thereof; similarly, an annular inner corrugated wall 143 is provided concentrically and in parallel with the edge corrugated wall 142 and radially inside thereof, the inner corrugated wall 143 extends vertically upward from the upper surface of the circular bottom plate portion 141 and horizontally extends at a tip end thereof toward the radially outer side by a distance to form an annular second horizontal extending portion 146, and the second horizontal extending portion 146 has an annular second sealing projection 147 at an outer edge thereof; alternatively, the inner corrugated wall 143 extends vertically upward from the upper surface of the circular bottom plate portion 141 and horizontally extends at its tip end toward the radially inner side by a distance to form an annular second horizontal extending portion 146, and the second horizontal extending portion 146 has an annular second sealing projection 147 at its outer edge.

As shown in fig. 1 and 5, the first seal projection 145 and a portion of the first horizontal extension 144 adjacent thereto are clamped and fixed to the lower surface of the carrier plate 13 by the outer peripheral upper portion of the annular pressure plate 15 via bolts (not shown), and the second sealing projection 147 and a portion of the second horizontal extension 146 adjacent thereto are clampingly fixed by the upper portion of the inner periphery of the annular pressure plate 15 to the lower portion of the inner periphery of the bottom of the stepped hole 131 of the carrier plate 13, thereby forming a relatively sealed second pressure chamber 24A of adjustable pressure and a third pressure chamber 24B of annular shape, gas may be introduced into or withdrawn from the second pressure chamber 24A through the first port 115 to regulate the pressure therein, and, similarly, gas may be introduced or withdrawn from the third pressure chamber 24B through other through-holes or fluid passages not shown to regulate the pressure of that chamber, thereby zonally fine-tuning the pressure profile applied to the substrate to achieve a more uniform and consistent polish.

As can be seen from the above description, the relative position between the carrier head 1 and the substrate in the vertical direction can be controlled by adjusting the pressure of the first pressure chamber 25, and the pressure profile applied to the substrate can be further adjusted by adjusting the pressures of the second pressure chamber 24A and the third pressure chamber 24B, in order to monitor the polishing process, in particular, the real-time thickness of the functional film layer on the substrate surface during the polishing process and determine the polishing endpoint, a series of devices such as an eddy current sensor and/or an optical sensor are also required to measure the polishing thickness of the substrate, i.e., the real-time thickness of the functional film layer on the substrate.

Although the embodiment shows the flexible membrane 14 having two independent pressure chambers, in order to further optimize the uniformity and consistency of chemical mechanical polishing, more pressure-adjustable chambers may be formed by providing more inner corrugated walls 143 having sealing structures and/or horizontal extensions, and accordingly, the annular platen 15 may be formed by combining a plurality of different annular platen members, illustratively, the annular platen 15 may be formed as an assembly, and the annular platen assembly 15 not shown may include 2, 3, 4, 5, 6, or 7 annular platen members that respectively clamp and bond part or all of the sealing portions of the inner side walls of the different pressure-adjustable chambers to the carrier plate 13; in other words, the number, structure, configuration and/or fitting form of the annular platen 15 and the inner corrugated wall 143 in the present embodiment should not be construed restrictively, but rather should be construed broadly with reference to the prior art, and the present embodiment omits the description of the prior art merely to highlight the core inventive concept thereof.

As shown in fig. 6, when the carrier head 1 presses the substrate 201 against a rotating polishing pad (not shown) to perform a polishing operation, the thickness of the metal film layer 202 on the surface of the substrate 201 needs to be measured by the eddy current film thickness measuring device 203 mounted on the polishing disk to determine the polishing endpoint, and since the metal material has a reflection function on the electromagnetic wave emitted by the eddy current film thickness measuring device 203 and the metal material generally transmits the electromagnetic wave, and the reflection intensity of the electromagnetic wave has a substantially positive correlation with the thickness of the metal film layer within a certain range, the film thickness can be measured by the eddy current film thickness measuring device 203 emitting the electromagnetic wave toward the metal film layer 202 on the substrate 201 and measuring the intensity of the electromagnetic wave reflected by the metal film layer 202. The gimbal 11 is generally made of a metal material having a high strength such as stainless steel so as to satisfy the strength requirement, however, when the bottom plate portion 112 of the gimbal 11 is made of a metal material, since it is closer to the eddy current film thickness measuring device 203 than the flange portion 114 so that it reflects the electromagnetic wave emitted from the eddy current film thickness measuring device 203 to a large extent, it has a hardly negligible influence on the thickness measurement accuracy of the metal film layer 202, thereby affecting the accuracy of the detection of the polishing end point.

For this reason, it is preferable to manufacture the gimbal 11 from a material having a low relative permeability and/or electric conductivity (closer to 1), such as austenitic stainless steel of 304, aluminum-magnesium alloy, and/or titanium alloy, and since the relative permeability of such a material is less than 1.01, the reflection of electromagnetic waves is very weak, and the influence on the measurement accuracy of the film thickness is acceptable. It should be understood that the structural dimensions and the proportional relationship in the drawings of the present embodiment or the present embodiment, particularly the dimensions of the substrate 201, the metal film layer 202, and the eddy current film thickness measuring device 203 in fig. 6 do not represent the actual dimensions thereof, nor represent the proportional relationship between the dimensions thereof, and are only shown for representing the functions thereof.

Although the metal material having a low relative magnetic permeability can reduce the influence of the bottom plate portion 112 of the balance frame 11 on the measurement signal of the eddy current sensor, since the thickness of the metal film layer is as thin as up to 1000nm and the error requirement on the measurement accuracy is generally less than 10nm, the influence of the material of the balance frame 11 on the film thickness measurement accuracy, that is, the reflection of the electromagnetic wave by the bottom plate portion 112 of the balance frame 11, needs to be further reduced in some cases.

Preferably, as shown in fig. 7, a wave absorbing layer 204 may be disposed on the lower surface of the chassis part 112 of the balance frame 11, the wave absorbing layer 204 has a thickness of generally 0.05mm to 2mm, and the wave absorbing layer 204 is generally made of a material such as ferrite, barium titanate, silicon carbide, graphite, metal powder, conductive fiber, chiral material, or the like. As will be readily appreciated, the wave-absorbing layer 204 can be bonded to the entire lower surface of the chassis portion 112 by a variety of different coating methods, such as adhering a wave-absorbing patch, applying an adhesive containing a wave-absorbing powder material, vapor depositing a wave-absorbing material, electroplating or spraying a wave-absorbing material, and preferably, the radius of the wave-absorbing layer 204 is greater than the radius of the chassis portion 112 to cover the bottom area of the outer surface of the adjacent peripheral wall portion 113 at the edge of the chassis portion 112, thereby further reducing the potential impact of the gimbal 11 on the film thickness measurement; it is easily understood that the wave-damping layer 204 does not cover the first through-hole 115.

In the foregoing embodiment, the balance frame 11 is generally integrally machined from a metal material to meet the strength requirement and the machining accuracy requirement, but it may alternatively be formed as a solution shown in fig. 8 in which the middle shaft portion 311 of the balance frame 31 is constituted by the middle shaft core 311A and the middle shaft sleeve 311B, in order to further reduce the influence of the chassis portion of the balance frame on the film thickness measurement; the middle shaft core 311A, the chassis part 312, the peripheral wall part 313 and the flange part 314 are integrally processed from the same non-metal material, the middle shaft sleeve 311B is made from the same metal material and is provided with a connecting hole for combining the middle shaft core 311A at the lower part of the inner part, and the size of the connecting hole is matched with that of the middle shaft core 311A so that the middle shaft core 311A can be completely and coaxially inserted and fixed in the connecting hole and simultaneously the airtight combination between the inner surface of the connecting hole and the outer surface of the middle shaft core 311A is ensured; the center shaft core 311A has a center shaft core through hole 315A extending therethrough along an axis thereof, the center shaft sleeve 311B has a center shaft sleeve through hole 315B extending therethrough along an axis thereof, and when the center shaft sleeve 311B is coupled to the center shaft core 311A, the center shaft core through hole 315A and the center shaft sleeve through hole 315B having the same radius are aligned with each other to form a balance frame through hole 315 extending therethrough along a rotation axis of the balance frame 31, where the through hole 315 of the balance frame 31 functions as well as the first through hole 115.

As shown in fig. 8, in consideration of the processing technology and strength requirement, the length-diameter ratio of the central axis is 2 to 6, preferably 3 to 5, but in some application scenarios, the central axis 311A may also extend vertically upward to the upper surface of the central axis sleeve 311B, i.e. the height of the central axis 311A (without the chassis part) is equivalent to the height of the central axis sleeve 311B; in consideration of the requirements for reflection and intensity of electromagnetic waves, the wall thickness of the hole of the connection hole at the lower portion of the middle shaft sleeve 311B should not exceed 50% of the thickness of the upper portion of the middle shaft sleeve 311B. Preferably, in order to ensure form and position tolerances between different parts of the gimbal 31, the gimbal through hole 315 formed by the central axis through hole 315A and the central bushing through hole 315B is formed by machining after fixedly combining the central axis 311A and the central bushing 311B, and at least one of the base plate part 312, the peripheral wall part 313 and the flange part 314 is formed by machining after fixedly combining the central axis 311A and the central bushing 311B.

The material forming the part of the central shaft core 311A is at least one of PPS plastic, PEEK plastic, PET plastic, POM plastic, ceramic material or semiconductor material, and it is preferable to add reinforcing material such as glass fiber, carbon fiber and/or ceramic or directly use composite plastic with better strength to manufacture these parts, or it is also possible to use titanium or titanium alloy to manufacture the central shaft core 311A; the middle sleeve 311B is preferably made of a metallic material having a relatively low magnetic permeability, such as austenitic stainless steel having a grade of 304, aluminum-magnesium alloy, titanium alloy, or the like. It should be understood that the diameter of the central axis 311A near the bottom plate 312 may be larger than the diameter of other parts to enhance the strength of the joint of the central axis 311A and the bottom plate 312, and the joint of the central axis 311A and the bottom plate 312 is preferably rounded to optimize the strength of the joint; further, in order to further reduce the influence that the middle bushing 311B made of metal may have on the measurement accuracy of the eddy current film thickness measuring apparatus 203, a layer of wave-absorbing material may be coated on the surface thereof, or a layer of wave-absorbing material may be coated on the area of the bushing 311B in contact with the root of the middle bushing core 311A to reduce the influence of the middle bushing 311B, particularly the root of the middle bushing 311B, on the eddy current detection signal.

In fact, the influence of the metal material on the eddy current signal also includes that the electromagnetic wave may form induced eddy current in the metal material, so that a part of the electromagnetic wave received by the eddy current film thickness measuring device 203 may come from the electromagnetic wave generated by the induced eddy current, which is one of the advantages of the configuration of the present invention that the metal material, the wave-absorbing material and the non-metal material with relatively low magnetic permeability are introduced into the components of the carrier head 1.

Further, as shown in fig. 2 and 8, the balance frame 31 is also different from the balance frame 11 in that the whole or a part of the chassis portion 312 of the balance frame 31 is formed as a downward projection, and the downward projection extends downward in the vertical direction not lower than the lower surface of the annular platen 15; such downward projection functions to prevent the central portion of the substrate from being excessively lifted due to excessive deformation of the second pressure chamber 24A during loading of the substrate, i.e., to be blocked by the downward projection when the central region of the substrate is excessively lifted, thereby preventing local excessive deformation of the substrate and/or damage to the substrate features that may be caused by excessive lifting of the lower portion of the inner edge of the annular platen 15; and the effect of configuring the downward projection to extend downward in the vertical direction to not lower than the lower surface of the annular platen 15 is to prevent the projection from approaching the substrate so much that the projection acts on the substrate prior to the annular platen 15 during substrate lifting, resulting in excessive force acting on the middle region of the substrate, thereby preventing excessive deformation or damage of the base plate middle portion of the bottom plate portion 312 due to excessive lifting.

The drawings in the present specification are schematic views to assist in explaining the concept of the present invention, and schematically show the shapes of respective portions and their mutual relationships. It should be understood that the drawings are not necessarily to scale, the same reference numerals being used to identify the same elements in the drawings in order to clearly show the structure of the elements of the embodiments of the invention. In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean 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, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. 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 invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (13)

1. The utility model provides a bear head for chemical mechanical polishing, includes shaft coupling dish, balancing stand, bears dish, flexible membrane, cyclic annular pressure disk, the well axial region slidable of balancing stand sets up in the central through-hole of shaft coupling dish and drives through its base portion and edge of a wing portion and bear the dish and reciprocate for the shaft coupling dish, a part of flexible membrane is pressed from both sides tightly to bearing the dish lower part by cyclic annular pressure disk and is formed the adjustable pressure cavity, a part of balancing stand is made by non-metallic material.

2. The carrier head of claim 1, wherein the middle shaft portion is formed by a middle shaft core and a middle shaft sleeve, the middle shaft sleeve has a connecting hole for combining with the middle shaft core, and an inner surface of the connecting hole of the middle shaft sleeve is tightly and fixedly combined with an outer surface of the middle shaft core so that the balance frame can be driven to move through the middle shaft sleeve.

3. The carrier head of claim 2, wherein the center sleeve is made of a metallic material.

4. The carrier head of claim 3, wherein the metallic material is one having a relative permeability of austenitic stainless steel or less.

5. The carrier head of claim 4, wherein the metallic material is titanium, a titanium alloy, an aluminum alloy, a magnesium alloy, or an austenitic stainless steel.

6. The carrier head of claim 1, wherein the non-metallic material is at least one of PPS plastic, PEEK plastic, PET plastic, POM plastic, ceramic material, or semiconductor material.

7. The carrier head of claim 2, wherein the center sleeve has a top portion that covers the center core.

8. The carrier head of claim 7, wherein the top portion has a diameter that is the same as an outer diameter of the middle boss.

9. The carrier head of claim 7 or 8, wherein the top portion extends vertically upward along the axis of rotation of the gimbal.

10. The carrier head of claim 2, wherein the central core has an aspect ratio of 2 to 6.

11. The carrier head of claim 10, wherein the central core has an aspect ratio of 3 to 5.

12. The carrier head of any of claims 1 to 8, wherein the middle shaft portion of the gimbal has a fluid passage extending therethrough along a central axis of rotation thereof for delivering fluid into the carrier head.

13. A chemical mechanical polishing apparatus, comprising a carrier head according to any one of claims 1 to 8.

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