CN115302403A

CN115302403A - Bearing head for chemical mechanical polishing and polishing equipment

Info

Publication number: CN115302403A
Application number: CN202111541581.6A
Authority: CN
Inventors: 李昆; 路新春
Original assignee: Tsinghua University; Huahaiqingke Co Ltd
Current assignee: Tsinghua University; Huahaiqingke Co Ltd
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2022-11-08
Anticipated expiration: 2041-12-16
Also published as: CN115302403B

Abstract

The invention discloses a bearing head for chemical mechanical polishing and polishing equipment, which comprises a base, an elastic membrane and a retaining ring, wherein the elastic membrane is concentrically arranged at the bottom of the base, and the retaining ring is fixed at the bottom of the base and positioned at the peripheral side of the elastic membrane; the polishing device also comprises an adjusting ring which is detachably connected to the bottom of the elastic membrane so as to limit a wafer to be polished inside the adjusting ring; the wafer to be polished and the adjusting ring are arranged at the bottom of the elastic membrane as a whole, and polishing liquid is conveyed to the adjusting ring and the bottom surface of the wafer through the groove on the bottom surface of the retaining ring so as to remove materials on the surface of the wafer.

Description

Bearing head for chemical mechanical polishing and polishing equipment

Technical Field

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

Background

The integrated circuit industry is the core of the information technology industry and plays a key role in the process of upgrading the boosting manufacturing industry to digitalization and intellectualization transformation. The chip is a carrier of an integrated circuit, and the chip manufacturing relates to the process flows of chip design, wafer manufacturing, wafer processing, electrical property measurement, cutting packaging, testing and the like. The Chemical Mechanical Polishing (CMP) is a global Planarization ultra-precise surface processing technology, and belongs to a wafer manufacturing process, wherein a wafer is attracted to the bottom surface of a bearing head, one surface of the wafer with a deposition layer is pressed against the upper surface of a polishing pad, and the bearing head rotates in the same direction as the polishing pad under the actuation of a driving component and gives downward load to the wafer; meanwhile, the polishing solution is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the chemical mechanical polishing of the wafer is completed under the combined action of chemistry and machinery.

FIG. 1 is a graph illustrating a prior art CMP carrier head and polished wafer material removal rate profile, wherein the flexible membrane of the carrier head is configured with three concentric chambers (Zone 1, zone2, and Zone 3) to zonally control the material removal rate of the wafer. The wafer may be divided into 3 polishing zones (Z1, Z2, and Z3) corresponding to the chambers of the elastic membrane. Since the wafer edge has the maximum rotation speed and the wafer edge supplies more polishing liquid, the material removal rate of the wafer edge region (Z3) is relatively high, so that the material in the wafer edge region is removed too quickly, thereby affecting the global polishing uniformity of the wafer, which is called "edge effect".

In order to polish the wafer more uniformly, the industry is required to divide the elastic membrane used for wafer operation into more chambers, such as 5 chambers, in the carrier head, and especially to arrange a complicated chamber at the edge position of the elastic membrane to increase the regulation capability of the edge area of the wafer. The elastomeric membranes of the five chambers cooperate to perform a compressive polishing operation to improve polishing uniformity and consistency as compared to a carrier head having only one chamber or less than five chambers.

As the technical solutions described in patents CN112847127a and US20150273657A1, the structure of two or three chambers at the edge position of the elastic membrane is optimized, which can enhance the effectiveness, stability, accuracy, etc. of the edge region regulation and control, and reduce the "edge effect" of the chemical mechanical polishing.

This increases the cost of manufacturing the carrier head due to the increasingly complex structure of the elastomeric membrane edge locations. Furthermore, existing elastomeric films are typically molded, and there are processing limitations to the mold tooling. With the downward movement of the polishing process node, the processing precision of the polishing process is close to the nm level, and the processing precision of the molding is far from meeting the requirement of the polishing process.

In summary, with the complexity of the edge structure of the elastic film, the processing limit is easily reached, so that the technical scheme cannot be realized or the realization cost is very high, and how to weaken or control the "edge effect" is always a difficult problem in the design of the carrier head.

Disclosure of Invention

The present invention aims to solve at least to some extent one of the technical problems existing in the prior art.

To this end, an embodiment of the present invention provides a carrier head and a polishing apparatus for chemical mechanical polishing, which includes a base, an elastic membrane concentrically disposed at the bottom of the base, and a retaining ring fixed at the bottom of the base and located at the outer peripheral side of the elastic membrane; the polishing device also comprises an adjusting ring which is detachably connected to the bottom of the elastic membrane so as to limit a wafer to be polished inside the adjusting ring; the wafer to be polished and the adjusting ring are arranged at the bottom of the elastic membrane as a whole, and polishing liquid is conveyed to the adjusting ring and the bottom surface of the wafer through the groove on the bottom surface of the retaining ring so as to remove materials on the surface of the wafer.

In a preferred embodiment, the bottom surface of the adjusting ring is flush with the bottom surface of the wafer to be polished.

In a preferred embodiment, the material of the adjusting ring is matched with the material to be removed from the bottom surface of the wafer.

In a preferred embodiment, the distance between the inner side wall of the adjusting ring and the outer edge of the wafer is not more than 0.1mm, and the adjusting ring is in clearance fit with the wafer, so that the adjusting ring and the wafer form a whole.

As a preferred embodiment, the adjusting ring is provided with a protective layer applied to the inner side wall of the adjusting ring; the protective layer is parylene to prevent debris from the wafer contacting the tuning ring.

In a preferred embodiment, a transition layer is arranged between the protective layer and the adjusting ring, and the transition layer is a rubber coating to increase the adhesiveness of the protective layer.

In a preferred embodiment, the inner side and the outer side of the bottom of the adjusting ring are provided with fillet structures, and the fillet structure on the inner side of the adjusting ring is larger than that on the outer side of the adjusting ring; the inner side of the top of the adjusting ring is provided with a clamping portion, and the size of the clamping portion is matched with the size of the edge chamfer of the wafer.

In a preferred embodiment, the adjusting ring has an outer edge flush with an outer edge of the elastic membrane, and the adjusting ring is magnetically attracted to the bottom of the elastic membrane.

As a preferred embodiment, the adjusting ring includes a connecting portion made of metal and having an abutting portion wrapped around an outer peripheral side thereof, and an abutting portion made of silicon or an oxide of silicon.

In addition, the invention also discloses polishing equipment which comprises the carrier head.

The beneficial effects of the invention include:

(1) The edge position of the bottom surface of the elastic membrane is provided with the detachable adjusting ring, and the wafer to be polished is arranged in the adjusting ring, so that the wafer to be polished and the adjusting ring are in clearance fit to form a whole, the polished edge effect acts on the adjusting ring but not on the edge area of the wafer, the control difficulty of the edge area of the wafer is effectively reduced, the regulation and control capability of the material removal rate of the edge area of the wafer is improved, and the uniformity of wafer polishing is favorably ensured;

(2) The inner side wall of the adjusting ring is coated with a protective layer to prevent the wafer from contacting with the adjusting ring to generate debris and avoid the influence of the debris formed by the contact of the wafer and the adjusting ring on the polishing of the wafer;

(3) The clamping part is arranged on the inner side of the top of the adjusting ring, the chamfer is arranged on the inner side of the bottom of the adjusting ring so as to effectively clamp and fix the wafer, and the adjusting ring and the wafer are formed into an integral structure, so that the material removal rate of the edge region of the wafer is favorably improved.

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 which do not limit the scope of protection of the invention, wherein:

FIG. 1 is a graph illustrating a prior art CMP carrier head and polished wafer material removal rate curve;

FIG. 2 is a schematic diagram of a carrier head for chemical mechanical polishing according to the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 2 at A;

FIG. 4 is a cross-sectional view of one embodiment of the adjusting ring of the present invention;

FIG. 5 is a cross-sectional view of another embodiment of the adjusting ring of the present invention;

FIG. 6 is a cross-sectional view of yet another embodiment of the adjusting ring of the present invention;

FIG. 7 is a partial schematic view of a wafer disposed within an adjustment ring according to the present invention;

FIG. 8 is a schematic view of the adjustment ring of the present invention pressed against a polishing pad;

FIG. 9 is a schematic view of a variant embodiment of the corresponding adjusting ring of FIG. 6;

FIG. 10 is a cross-sectional view of yet another embodiment of the adjustment ring of the present invention;

FIG. 11 is a schematic view of the adjusting ring of FIG. 10 magnetically attracted to the bottom of the elastic membrane;

FIG. 12 is a schematic view of a polishing apparatus 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 illustrative and exemplary in nature and is not to be construed as limiting the embodiments of the invention and 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.

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 present invention, "Chemical Mechanical Polishing (CMP)" is also referred to as "Chemical Mechanical Planarization (CMP)", and wafers (Wafer, W) are also referred to as substrates (substrates) and Carrier heads are also referred to as Polishing heads (Polishing heads), and their meanings and practical effects are equivalent.

With the progress of miniaturization and multilayer formation of integrated circuits, the processing accuracy of each step in the manufacture of semiconductor devices has reached the order of several nm, which has made higher demands on CMP. Thus, there is a need to continuously increase the global planarization level of chemical mechanical polishing.

A carrier head for chemical mechanical polishing according to the present invention is schematically illustrated in FIG. 2. The carrier head 100 includes a base 10, an elastic membrane 20, and a retaining ring 30; the elastic membrane 20 is concentrically arranged at the bottom of the base 10 to attract the wafer to be polished; the retainer ring 30 is fixed to the bottom of the susceptor 10 and located on the outer circumferential side of the elastic membrane 20 to prevent the polished wafer from slipping out of the carrier head, while the bottom surface of the retainer ring 30 is provided with grooves to ensure the normal supply of the polishing liquid.

Further, the carrier head 100 further includes a conditioning ring 40, and the conditioning ring 40 is detachably connected to the bottom of the flexible membrane 20 to confine the wafer to be polished inside the conditioning ring 40. That is, the wafer W to be polished and the adjusting ring 40 are integrally disposed at the bottom of the elastic membrane 20, and the materials of the wafer W and the bottom surface of the adjusting ring 40 are simultaneously removed by the combined chemical and mechanical actions.

As an embodiment of the present invention, the material of the tuning ring 40 matches the material to be removed from the bottom surface of the wafer. Specifically, the material of the adjusting ring 40 is substantially the same as the material of the wafer to be removed. So configured, the wafer W and the adjustment ring 40 are equivalent to a "wafer" of increasing size. The carrier head 100 holds the wafer W and the adjustment ring 40 together and then performs load polishing, since the edge effect of the cmp mainly affects the position of the adjustment ring 40, not the edge region of the wafer in the conventional carrier head structure. That is, the adjusting ring 40 is used as a consumable part to control the polishing removal rate of the wafer W disposed inside the adjusting ring 40, thereby improving the material removal rate of the edge region of the wafer and enhancing the polishing uniformity of the wafer. The adjusting ring 40 is skillfully arranged, so that the removal rate of the edge area of the wafer is effectively controlled, and the problem of nm-level polishing is solved; meanwhile, the bearing head effectively reduces the design difficulty of the structure and control of the edge position of the elastic membrane, avoids the processing limit of die manufacturing, and effectively controls the cost of the polishing head.

As one aspect of this embodiment, the tuning ring 40 may be made of silicon or an oxide of silicon, such as SiO ₂ And (4) preparing. The material of the adjustment ring 40 substantially conforms to the material of the wafer W to be removed, so that the adjustment ring 40 and the wafer W are integrated into a single body for chemical mechanical polishing.

Fig. 3 is a partially enlarged view of a portion a in fig. 2. The bottom surface of the adjusting ring 40 is flush with the bottom surface of the wafer W to be polished to ensure the synchronicity of the polishing of the adjusting ring 40 and the wafer W. In this way, the edge effect of polishing is concentrated in the conditioning ring 40 rather than the edge region of the wafer W.

Further, the outer edge of the adjusting ring 40 is flush with the outer edge of the elastic membrane 20, as shown in fig. 3, so as to control the aggregation of particles at the joint of the adjusting ring 40 and the elastic membrane 20, and prevent the wafer surface from being scratched due to the falling of the particle crystals.

In the embodiment shown in fig. 2, the gap between the inner sidewall of the adjusting ring 40 and the outer edge of the wafer W is not greater than 0.1mm, and the adjusting ring 40 is in clearance fit with the wafer W such that the adjusting ring 40 and the wafer W are integrally formed. Specifically, on the premise of ensuring that the wafer W is smoothly attracted to the inside of the adjusting ring 40, the gap between the inner side wall of the adjusting ring 40 and the outer edge of the wafer W is reduced as much as possible so that the two are reliably combined into a whole, the polishing edge effect acts on the position of the adjusting ring 40, the control difficulty of the polishing pressure of the edge region of the wafer is reduced, and the manufacturing cost of the carrier head is reduced.

Since the wafer is a hard material with silicon as the main body, the material of the adjusting ring 40 is the same as the material of the wafer. During the polishing process, the wafer W will move laterally under the action of friction force, so that the edge of the wafer W abuts against the inner sidewall of the adjusting ring 40. The impact of the two hard materials creates debris that is highly likely to fall onto the polishing pad and scratch the polished wafer.

In order to solve the above problems, the adjusting ring 40 of the present invention is provided with a protective layer 51, as shown in fig. 4, coated on the inner sidewall of the adjusting ring 40 to prevent the wafer W from hard contact with the adjusting ring 40 and generating debris. As an embodiment of the present invention, the protective layer 51 may be parylene, such as parylene C, uniformly applied to the inner sidewall of the tuning ring 40 to prevent the wafer and the tuning ring from hard contact with each other to generate debris. Specifically, the wall thickness of the protective layer 51 is 0.05-0.2mm, and the thickness uniformity of the coating of the protective layer 51 is controlled within 0.01 mm.

To increase the adhesion of the protective layer 51, a transition layer 52 is disposed between the protective layer 51 and the adjusting ring 40, as shown in FIG. 5. Preferably, the transition layer 52 is a rubber coating that is uniformly applied to the inner side wall of the adjusting ring 40 to ensure a reliable fixation of the protective layer 51.

In another embodiment of the present invention, a chamfer structure 41 is disposed on the inner side of the bottom of the adjusting ring 40, as shown in fig. 6, to ensure that the wafer W is smoothly sucked and fixed by the elastic membrane 20. Specifically, the size of the chamfering structure 41 is smaller than the size of the edge chamfer of the wafer W, so that the wafer W does not collide with the bottom surface of the adjusting ring 40, and the smoothness of suction of the wafer W is ensured. In addition, the chamfer structure 41 is also arranged to effectively prevent the adjusting ring 40 from directly abutting against the polishing pad to form chips.

In the embodiment shown in FIG. 6, the adjustment ring 40 is primarily for a wafer having a T-type edge configuration and the bevel 41 is beveled; it is understood that the chamfered structure 41 may also be rounded.

Further, the inner side of the top of the adjusting ring 40 is provided with a snap-in portion 42 shown in fig. 6, and the bottom surface of the snap-in portion 42 is matched with the edge chamfer of the wafer W, so that the snap-in portion 42 of the adjusting ring 40 can be precisely covered on the top of the wafer W. Specifically, the clamping portion 42 extends from the top of the adjusting ring 40 toward the inner side, and the inclined surface of the clamping portion 42 extending toward the inner side forms an included angle θ with the bottom surface of the adjusting ring 40; the included angle theta is 10-60 degrees, preferably 20-45 degrees, and the inclined surface of the clamping portion 42 abuts against the edge chamfer of the wafer W, so that the adjusting ring 40 and the wafer W are combined into a whole. FIG. 7 shows a partial schematic view of a wafer W disposed within the conditioning ring 40, with edge effects of polishing acting on the conditioning ring 40.

In FIG. 6, the width D of the bottom of the conditioning ring 40 matches the active area width of the polishing edge effect so that wafers disposed inside the conditioning ring 40 are not affected by the polishing edge effect. Specifically, the width D is any value within the range of 1-5mm, and preferably, the width D of the bottom of the adjusting ring 40 is 2-4mm. It will be appreciated that the width of the adjustment ring 40 is not too large. This is because the size of the adjustment ring 40 is directly related to the size of the relevant components of the carrier head 100, which directly affects the cost of manufacturing the carrier head 100.

Fig. 8 is a schematic view showing the polishing pad 200 pressed by the adjusting ring 40, and the polishing pad 200 is deformed by the pressing of the adjusting ring 40. As can be seen in FIG. 8, the bottom edge of the conditioning ring 40 is first worn by the polishing pad 200 to produce debris.

To control and avoid the effects of debris formed at the edge of the adjustment ring 40 on the chemical mechanical polishing, the inner 41a and outer 41b chamfer structures of the adjustment ring 40 are rounded as shown in FIG. 9. Preferably, the inner chamfer 41a is larger in size than the outer chamfer 41 b. The inner chamfer structure 41a has two functions, one is to ensure the wafer W to be smoothly clamped inside the adjusting ring 40, and the other is to prevent the edge of the adjusting ring 40 from being worn to form chips, which may scratch the surface of the polished wafer. In contrast to the inner chamfer 41a, the outer chamfer 41b only has the effect of preventing wear of the edge of the adjusting ring 40.

As an embodiment of the present invention, the adjusting ring 40 is concentrically disposed at the bottom of the elastic membrane 20. Specifically, the adjusting ring 40 is magnetically fixed to the bottom of the elastic membrane 20. In order to ensure the concentricity of the adjusting ring 40 and the elastic membrane 20, the bottom surface of the elastic membrane 20 and the top surface of the adjusting ring 40 are provided with a convex structure and a clamping structure, so as to ensure the installation precision of the adjusting ring 40 through accurate limit.

It is understood that the adjusting ring 40 may be disposed at the bottom of the elastic membrane 20 by vacuum suction. This requires a vacuum suction line to be disposed at the edge of the elastic membrane 20, a suction passage to be disposed in the thickness direction of the adjustment ring 40, and the adjustment ring 40 to be fixed to the bottom of the elastic membrane 20 by vacuum suction.

In the chemical mechanical polishing, the adjusting ring 40 is first concentrically disposed at the bottom of the elastic membrane 20, and then the wafer W to be polished is picked up according to the process steps. In order to ensure the reliability of the pull-in of the adjusting ring 40, the magnetic attraction force of the adjusting ring 40 is between 10 and 200N. Since the polished wafer W is attracted by the elastic membrane 20, the reversed confinement of the conditioning ring 40 by the wafer W also prevents the conditioning ring 40 from excessively shifting laterally to affect the symmetry of the cmp.

Fig. 10 is a cross-sectional view of yet another embodiment of the adjusting ring of the present invention, the adjusting ring 40 including a connecting portion 40A and an abutting portion 40B, the abutting portion 40B being located on the lower side of the connecting portion 40A. Further, the connection portion 40A may be made of metal, so that the connection portion 40A may be directly magnetized to the bottom surface of the elastic membrane 20; the abutting portion 40B may be made of Si or SiO ₂ Is made to ensure that the material removal rate of the abutment portion 40B is substantially the same as the material removal rate of the wafer W.

Since the connection portion 40A is metal, it may form metal ions and become a source of metal ion contamination. In order to cut off this contamination source, the surface of the connecting portion 40A needs to be provided with a Polytetrafluoroethylene (PTFE) coating to form an effective protection on the surface of the connecting portion 40A and prevent metal ion contamination during the chemical mechanical polishing process. Preferably, the polytetrafluoroethylene coating is coated on the outer surface of the connecting portion 40A entirely, and the thickness of the coating is controlled to be 0.05-0.2mm. It is understood that the outer surface of the connecting portion 40A may be coated with materials such as fluorinated ethylene propylene, polyethylene, etc. as a coating layer to prevent the metal connecting portion 40A from generating metal ions to be released in the chemical mechanical polishing environment.

Fig. 11 is a schematic view of the adjusting ring 40 shown in fig. 10 magnetically attracted to the bottom of the elastic membrane 20, a magnetic ring 60 is disposed at an inner edge of the elastic membrane 20, and the adjusting ring 40 is magnetically attracted to the bottom of the elastic membrane 20. It is understood that the magnetic ring 60 may be disposed on the bottom surface or inside the elastic membrane 20 to achieve the detachable installation of the adjusting ring 40, thereby ensuring the flexibility of assembling the adjusting ring 40.

During chemical mechanical polishing, the outer edge of the wafer may abut against the inner sidewall of the conditioning ring 40 under lateral force, causing scratches to occur on the inner sidewall. The wafer polishing consistency can be ensured by a mode of regular detection and replacement. Because the adjusting ring 40 is convenient to detect and disassemble and the size of the adjusting ring 40 is small, the manufacturing cost is reduced, which is beneficial to controlling the wafer polishing cost to a certain degree.

In addition, the invention also discloses a polishing apparatus 1000, which comprises the carrier head 100, wherein the polishing apparatus 1000 comprises a polishing disk 300, a polishing pad 200, the carrier head 100, a dresser 400 and a liquid supply part 500, wherein the carrier head 100 is shown in figure 1; the polishing pad 200 is disposed on the upper surface of the polishing disk 300 and rotates along the axis Ax; the horizontally movable carrier head 100 is disposed above the polishing pad 200, and a lower surface thereof receives a wafer to be polished; the dresser 400 includes a dresser arm and a dresser head, which are disposed at one side of the polishing disk 300, and the dresser arm drives the rotating dresser head to swing to dress the surface of the polishing pad 200; the liquid supply part 500 is provided at an upper side of the polishing pad 200 to distribute the polishing liquid to the surface of the polishing pad 200.

During polishing operation, the carrier head 100 presses the surface of the wafer to be polished against the surface of the polishing pad 200, and the carrier head 100 performs a rotation motion and a reciprocating motion along the radial direction of the polishing disk 300 to gradually remove the surface of the wafer contacting the polishing pad 200; meanwhile, the polishing platen 300 rotates, and the liquid supply part 500 sprays polishing liquid onto the surface of the polishing pad 200. The wafer is rubbed against the polishing pad 200 by the relative movement of the carrier head 100 and the polishing platen 300 under the chemical action of the polishing liquid to perform polishing.

Polishing liquid consisting of submicron or nanometer abrasive particles and chemical solution flows between a wafer and a polishing pad 200, the polishing liquid is uniformly distributed under the action of transmission and rotation centrifugal force of the polishing pad 200 to form a layer of liquid film between the wafer and the polishing pad 200, chemical components in the liquid and the wafer generate chemical reaction to convert insoluble substances into easily soluble substances, then the chemical reactants are removed from the surface of the wafer through micro-mechanical friction of the abrasive particles and dissolved into the flowing liquid to be taken away, namely surface materials are removed in the alternate process of chemical film forming and mechanical film removing to realize surface planarization treatment, thereby achieving the purpose of global planarization.

During chemical mechanical polishing, the dresser 400 is used to dress and activate the topography of the polishing pad 200. The dresser 400 can remove foreign particles remaining on the surface of the polishing pad, such as abrasive particles in the slurry and waste materials falling off from the surface of the wafer, and can also planarize the surface deformation of the polishing pad 200 caused by the grinding, thereby ensuring the consistency of the surface topography of the polishing pad 200 during the polishing process and stabilizing the removal rate of the polishing.

The carrier head 100 of the present invention is configured with the adjusting ring 40, and the adjusting ring 40 is magnetically attracted to the bottom surface of the elastic membrane 20, which can act the edge effect of the chemical mechanical polishing on the adjusting ring 40 instead of the edge region of the wafer W, thereby effectively reducing the control difficulty of the edge region of the wafer and improving the polishing uniformity of the wafer surface.

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 present 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

1. A bearing head for chemical mechanical polishing is characterized by comprising a base, an elastic membrane and a retaining ring, wherein the elastic membrane is concentrically arranged at the bottom of the base, and the retaining ring is fixed at the bottom of the base and positioned at the outer peripheral side of the elastic membrane; the polishing device also comprises an adjusting ring which is detachably connected to the bottom of the elastic membrane so as to limit a wafer to be polished inside the adjusting ring; the wafer to be polished and the adjusting ring are arranged at the bottom of the elastic membrane as a whole, and polishing liquid is conveyed to the adjusting ring and the bottom surface of the wafer through the groove on the bottom surface of the retaining ring so as to remove materials on the surface of the wafer.

2. The carrier head of claim 1, wherein a bottom surface of the adjustment ring is flush with a bottom surface of a wafer to be polished.

3. The carrier head of claim 1 wherein the material of the adjustment ring matches the material to be removed from the bottom surface of the wafer.

4. The carrier head of claim 1, wherein the distance between the inner sidewall of the adjustment ring and the outer edge of the wafer is no greater than 0.1mm, the adjustment ring being a clearance fit with the wafer such that the adjustment ring is integral with the wafer.

5. The carrier head of claim 1, wherein the adjustment ring is configured with a protective layer applied to an inner sidewall of the adjustment ring; the protective layer is parylene to prevent debris from the wafer contacting the tuning ring.

6. The carrier head of claim 5, wherein a transition layer is disposed between the protective layer and the adjustment ring, the transition layer being a rubber coating to increase adhesion of the protective layer.

7. The carrier head of claim 1, wherein the adjustment ring is configured with a fillet configuration on an inner side and an outer side of the bottom of the adjustment ring, the fillet configuration on the inner side of the adjustment ring being larger than the fillet configuration on the outer side thereof; the inboard at adjustable ring top disposes joint portion, the size of joint portion and the marginal chamfer size phase-match of wafer.

8. The carrier head of claim 1, wherein the adjustment ring has an outer edge that is flush with an outer edge of the flexible membrane and magnetically attracts a bottom of the flexible membrane.

9. The carrier head of claim 1, wherein the adjustment ring comprises a connecting portion made of metal and having an abutment portion wrapped around its outer circumference, the abutment portion being made of silicon or an oxide of silicon.

10. A polishing apparatus comprising the carrier head of any one of claims 1 to 9.