CN112792728B

CN112792728B - Flexible membrane for chemical mechanical polishing, bearing head and polishing equipment

Info

Publication number: CN112792728B
Application number: CN202110146610.2A
Authority: CN
Inventors: 赵德文; 王宇; 路新春
Original assignee: Huahaiqingke Co Ltd
Current assignee: Huahaiqingke Co Ltd
Priority date: 2021-02-03
Filing date: 2021-02-03
Publication date: 2022-11-22
Anticipated expiration: 2041-02-03
Also published as: CN112792728A

Abstract

The invention discloses a flexible film for chemical mechanical polishing, a carrier head and polishing equipment, wherein the flexible film comprises a bottom plate part for receiving a substrate; an annular edge side wall having a vertical portion extending upward along a peripheral edge of the bottom plate portion, a bent portion provided on an upper side of the vertical portion, and a first horizontally extending portion extending horizontally inward from an upper end of the bent portion; the inner side wall is concentrically and adjacently arranged with the edge side wall, and the top end of the inner side wall is provided with a second horizontal extending part which is bent to the inner side and horizontally extends; and a partition plate extending radially inward from an inner surface of the rim side wall, the partition plate having a wall thickness smaller than a thickness of the bottom plate portion, an inner edge of the partition plate being closer to a center position of the bottom plate portion than an inner edge of the first horizontally extending portion.

Description

Flexible membrane for chemical mechanical polishing, bearing head and polishing equipment

Technical Field

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

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. Wherein, the chemical mechanical polishing belongs to the wafer manufacturing process.

Chemical Mechanical Polishing (CMP) is a globally planarized ultra-precise surface processing technique. Chemical mechanical polishing generally attracts a wafer to a bottom surface of a carrier head, the surface of the wafer having a deposition layer is pressed against an upper surface of a polishing pad, and the carrier head rotates in the same direction as the polishing pad under the actuation of a driving assembly and gives a 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.

In a prior art CMP carrier head, a multi-chamber membrane having five chambers with adjustable pressure applied to different annular regions of a substrate, the five chambers cooperating to perform a pressure polishing operation can improve polishing uniformity and consistency compared to a carrier head having only one chamber or less than five chambers. For more uniform polishing of the substrate, it is desirable to divide the membrane used in the carrier head for substrate processing into more chambers, such as six chambers that are pressure adjustable.

In addition, the number of the chambers is increased, and meanwhile the 'edge effect' (the wafer edge polishing is difficult to regulate and control, and over-polishing is caused by the reason that the rotating speed is higher than the inner side of the wafer and the like) is reduced as much as possible, namely, the regulating and controlling effectiveness, stability, accuracy and the like of the region are enhanced by carrying out structural optimization on two or three chambers at the outermost edge.

In summary, it is desirable to provide a chemical mechanical carrier head that addresses the problems of polishing uniformity, edge effects, loading effectiveness, loading reliability, loading accuracy, and the like, particularly the problems of substrate edge over-polishing and/or under-polishing, which, however, generally affect each other and make the design of the carrier head difficult to balance.

Disclosure of Invention

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

According to one aspect of the present invention, there is provided a flexible membrane for chemical mechanical polishing, comprising: a bottom plate portion for receiving a substrate; an annular edge side wall having a vertical portion extending upward along a peripheral edge of the bottom plate portion, a bent portion provided on an upper side of the vertical portion, and a first horizontal extending portion extending horizontally inward from an upper end of the bent portion; the inner side wall is concentrically and adjacently arranged with the edge side wall, and the top end of the inner side wall is provided with a second horizontal extending part which is bent to the inner side and horizontally extends; and a partition plate extending from an inner surface of the edge side wall toward a radially inner side, the wall thickness of the partition plate being smaller than the wall thickness of the bottom plate portion, an inner edge of the partition plate being closer to a center position of the bottom plate portion than an inner edge of the first horizontally extending portion.

In a preferred embodiment, the spacer is formed to extend horizontally inward from the inner surface of the edge sidewall.

In a preferred embodiment, the wall thickness of the partition plate is 1/3 to 1 of the wall thickness of the upright portion.

As a preferred embodiment, the partition plate includes a first horizontal portion of the partition plate horizontally extending inward from the inner surface of the edge side wall, a protruding portion formed by arching an end portion of the first horizontal portion of the partition plate toward an upper side, and a second horizontal portion of the partition plate horizontally extending inward from an end portion of the protruding portion, which are integrally molded.

In a preferred embodiment, the first horizontal portion of the partition plate and the second horizontal portion of the partition plate are located on the same horizontal plane.

In a preferred embodiment, the second horizontal portion of the partition plate is located at an upper side of the first horizontal portion of the partition plate.

In a preferred embodiment, the height difference between the bottom surface of the second horizontal part of the partition board and the bottom surface of the first horizontal part of the partition board is 3mm-10mm.

As a preferred embodiment, the partition plate extends inwards horizontally from the inner surface of the edge side wall and then extends upwards and inwards in an inclined manner, and the included angle between the upwards and inwards inclined extension section and the horizontal plane is 5-45 degrees.

According to another aspect of the invention, a chemical mechanical carrier head is provided that includes the flexible membrane described above for chemical mechanical polishing.

According to another aspect of the invention, there is provided a polishing apparatus comprising the chemical mechanical carrier head described above.

The beneficial effects of the invention include: the structure of the edge chamber is optimized, so that the regulation effectiveness, stability, accuracy and the like of the region are enhanced, and a chemical mechanical polishing flexible film, a bearing head and polishing equipment are provided to solve the problems of polishing uniformity, consistency, edge effect, loading effectiveness, loading reliability, determined loading and the like, particularly solve the problems of over-polishing and/or under-polishing and the like of the edge part of the substrate to a certain extent; in addition, 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 present invention will become more apparent and more readily appreciated from the detailed description set forth below when taken in conjunction with the drawings, which are given by way of illustration only, and which are not intended to limit the scope of the invention, wherein:

FIG. 1 is a schematic diagram of a carrier head 300 for chemical mechanical polishing according to the present invention;

FIG. 2 is a schematic diagram of the structure of the flexible membrane 14 according to the present invention;

FIG. 3 is an enlarged partial view of the edge portion of the flexible membrane 14 of FIG. 2;

FIGS. 4-7 are schematic views of the edge portion of the flexible membrane 14 of the present invention;

FIG. 8 is a prior art deformation of the upstanding portion 142 of the flexible membrane 14' in a pressurized state;

fig. 9 is a schematic view of the structure of a polishing apparatus 1000 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 invention, and are presented to illustrate 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.

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 will be appreciated that in order to facilitate a clear presentation of the structure of the various elements of an embodiment of the invention, the figures are not drawn to scale and that like reference numerals have been used to indicate like parts in the figures.

The chemical mechanical polishing apparatus is called polishing apparatus for short, and generally includes a polishing disk, a polishing pad, a liquid supply device, a dressing device, a detection device, a control device, etc., and its constituent schemes are fully embodied in the prior art as the prior art, and are not described in detail in the present invention, but it should be understood that the chemical mechanical polishing apparatus according to the present invention also includes necessary parts and components for operations of the polishing disk, the polishing pad, the liquid supply device, the dressing device, the detection device, the control device, etc. The following description will mainly describe the configuration and function of a core carrier head in a chemical mechanical polishing apparatus according to the present invention, and the carrier head described below can be applied to the chemical mechanical polishing apparatus according to the present invention. It should be noted that, unless otherwise specified, the inward and radially inward directions in the present embodiment refer to inward along the radius direction of the bottom plate portion 141, and the outward and radially outward directions refer to outward along the radius direction of the bottom plate portion 141; and any of the features described below with respect to the carrier head and the flexible membrane can be combined and/or formed separately so long as the features and/or combination of features improves the performance of the cmp process and the process results; furthermore, the terms in the present invention should be interpreted and understood according to the actual functions of the parts, components, members, assemblies, etc., if they are inconsistent with national or international standards or prior or subsequent applications, and should not be taken as a basis for limiting the scope of the present invention. In the present invention, "Chemical Mechanical Polishing (CMP)" is also referred to as "Chemical Mechanical Planarization (CMP)", and a Wafer (Wafer) is also referred to as a Substrate (Substrate), and a Material Removal Rate (MRR), which means and actually works equally.

As shown in fig. 1, the present invention provides a chemical mechanical polishing head 300, which will be referred to hereinafter for convenience as a carrier head for descriptive purposes. The carrier head 300 comprises a gimbal 11, an adapter disc 12, a carrier disc 13, a flexible membrane 14, an annular pressure disc 15, a retaining ring 16, a first clamping ring 18, a second clamping ring 19, a third clamping ring 20, an annular elastic membrane 21, etc., wherein the adapter disc 12 is connected to an external drive shaft to move and/or rotate the entire carrier head 300. Specifically, the second clip ring 19 and the third clip ring 20 clamp-couple the outer edge and the inner edge of the elastic mold 21 to the carrier plate 13 and the coupling plate 12, respectively, so that the carrier plate 13 can rotate integrally with the coupling plate 12.

A balance frame 11 having a central shaft portion slidably inserted into a central shaft hole of the coupling disc 12 and movable in a vertical direction, a base portion, a peripheral wall portion, and a flange portion is coaxially disposed with the coupling disc 12, and the flange portion thereof is coupled to a central stepped hole of the carrier disc 13 by means of a washer 17, a first clip ring 18, and a bolt, not shown, so that the carrier disc 13 can rotate together with the balance frame 11 and/or move in a vertical direction.

The flexible membrane 14 is clamped to the lower part of the carrier plate 13 by an annular pressure plate 15 and can move and/or rotate together with the carrier plate 13; the flexible membrane 14, the annular pressure plate 15 and the carrier plate 13 cooperate to form seven adjustable pressure chambers C1, C2, C3, C4, C5, C6 and C7, which can be adjusted and controlled respectively. Although not illustrated, it is understood that a plurality of gas passages are disposed in the carrier head 300, and the gas passages are connected to the adjustable pressure chambers through the coupling plate 12, the carrier plate 13, and the annular pressure plate 15, respectively, so as to adjust the pressure of the chambers by introducing gas into the chambers or extracting gas from the chambers; in particular, the pressure of the pressure-adjustable chamber C8 can be adjusted by a through-hole in the coupling disc 12 extending in the vertical direction parallel to the central axis portion of the balance frame 11 to adjust the displacement of the carrier disc 13 and the flexible film 14 in the vertical direction relative to the coupling disc 12.

According to the structural schematic diagram of the flexible film 14 of the present invention, as shown in fig. 2, the flexible film 14 includes a circular bottom plate 141, a vertical part 142 extending substantially vertically upward along the bottom plate 141, a bent part 143 connected to a top end of the vertical part 142, and a first horizontal extending part 145 extending horizontally inward from an upper end of the bent part 143.

The free end of the first horizontal extension 145 has a sealing portion 145a protruding downward toward the inside in the vertical direction, and in order to enhance the rigidity of the upright portion 142 so that it can transmit a force downward toward the inside in the vertical direction more effectively, the outer side surface of the upright portion 142 is formed with an annular groove for providing an outer support ring of a flexible film, the groove extending toward the inside in the radial direction and having a thickness not more than half of the wall thickness of the upright portion 142, so that the outer support ring of the flexible film can be stably engaged in the groove, the outer support ring of the flexible film and the groove extending upward to a position close to the lower end of the bent portion 143 and downward to a position 0.5mm to 4mm from the upper surface of the bottom plate portion 141, and particularly, the outer support ring of the flexible film after being engaged in the groove, extends in the radial direction to not more than 2mm from the radially outer surface of the upright portion 142 so as to avoid formation of polishing liquid crystals in the region near the lower portion of the outer support ring.

Further, an annular groove extending radially inward is formed inside the root of the upright part 142 and the bottom plate part 141, and the annular groove has the function of enhancing the degree of freedom of the root of the upright part 142 of the edge side wall to prevent stress concentration and local buckling, so that the removal rate regulation and adjustment effect of the substrate edge region is relieved to a certain extent; in order to further enhance the rigidity of the upright portion 142 so that the pressure of the upper chamber thereof can be more transmitted downward to the region directly below it, in view of the inconvenience of providing an excessively thick outer support ring of a flexible film, an inner support ring of a flexible film may be provided on the inner surface of the upright portion 142.

In the embodiment shown in FIG. 2, the flexible membrane 14 further includes an inner sidewall 144 disposed concentrically adjacent the edge sidewall, the inner sidewall 144 having a second horizontal extension 147 at a top end thereof that curves inwardly and extends horizontally; the flexible membrane 14 further includes a spacer plate 146 extending from the inner surface of the edge side wall toward the radially inner side, the spacer plate 146 having a wall thickness smaller than the thickness of the bottom plate portion 141, and the inner edge of the spacer plate 146 is located closer to the center of the bottom plate portion 141 than the inner edge of the first horizontally extending portion 145 to increase the overall flexibility of the flexible membrane 14. Preferably, the wall thickness of the partition plate 146 is 1/3-1 of the thickness of the bottom plate 141, so as to control the inward pulling force of the partition plate 146 on the upright portion 142 during pressurization, thereby improving the flexibility of pressure regulation of the chambers C1 and C2. In the present invention, the inner edge refers to a portion of the rib extending toward the inner side of the flexible membrane 14 near the center of the flexible membrane.

Fig. 3 is a partially enlarged view of the edge portion of the flexible film 14 in fig. 2, and a recessed portion 141a is provided on the inner side where the bottom plate portion 141 meets the rising portion 142. That is, the thickness of the edge portion of the bottom plate portion 141 is tapered from the inside to the outside to regulate the removal rate of polishing at a local area of the edge of the substrate. The bending portion 143 includes a first bending portion 143a bending and extending upward and inward from an upper end of the upright portion and a second bending portion 143b bending and extending upward and outward from the first bending portion 143a, and an included angle between the first bending portion 143a and a horizontal plane is not equal to an included angle between the second bending portion 143b and the horizontal plane. With this arrangement, it is advantageous to improve the flexibility of the bent portion 143, so that the internal pressure in the chamber C1 can be controlled more freely.

As an embodiment of the present invention, an included angle between the first bent portion 143a and a horizontal plane is smaller than an included angle between the second bent portion 143b and the horizontal plane. The first horizontal extension portion 145 is connected to the carrier tray 13, the bending portion 143 is connected to the first horizontal extension portion 145, and an included angle of the bending portion 143 is set, so as to facilitate the edge portion of the flexible film 14 to generate a lifting force, so that a polishing pressure of the edge portion of the flexible film 14 is smaller than that of other portions, so as to adjust a material removal rate of the edge portion of the corresponding substrate, and improve global polishing uniformity of the substrate.

In one aspect of the present embodiment, an angle between the first bent portion 143a and the horizontal plane is smaller than an angle between the second bent portion 143b and the horizontal plane by 1 to 10 °. Preferably, an included angle between the first bending part 143a and the horizontal plane is smaller than an included angle between the second bending part 143b and the horizontal plane by 3 to 8 degrees, so as to improve the polishing pressure of the edge region of the flexible film and adjust and control the polishing removal rate of the edge region of the substrate.

Further, an included angle between the first bent portion 143a and the horizontal plane is 1 to 25 °, and preferably, an included angle between the first bent portion 143a and the horizontal plane is 3 to 5 °, so as to improve flexibility of the bent portion 143.

In the embodiment shown in fig. 2, the bent portion 143 extends outwardly no further than the circumferential outer surface of the upright portion 142 to ensure that the load of the chamber C1 is fully applied within the bottom plate portion 141 of the flexible membrane 14. I.e. the load of the edge portion of the flexible membrane 14 is applied completely to the edge area of the substrate without creating an ineffective load. Preferably, the bending portion 143 may be offset toward the inner side of the flexible film 14, for example, the distance between the bending portion 143 and the outer circumferential surface of the standing portion 142 may be 0.5mm to 3mm, so as to adjust the polishing pressure at a position of the edge of the substrate and adjust the material removal rate at the position.

In the embodiment shown in fig. 3, the spacer 146 extends horizontally inward from the inner surface of the edge sidewall and is provided with a sealing connection at its end to sealingly engage the annular platen 15. To ensure the flexibility of the chamber C1, the wall thickness of the partition plate 146 is smaller than that of the first horizontally extending portion 145; preferably, the wall thickness of the spacer plate 146 is 50% -75% of the wall thickness of the first horizontally extending portion 145.

In order to improve the stress condition of the root portion of the partition plate 146 and thus improve the accuracy, reliability, and the like of the downward pressure transmission of the upright portion 142, it is preferable that a locally thickened structure is formed on the upper surface of the root portion region of the partition plate 146, which is joined to the upright portion 142, and the cross section of the locally thickened structure is formed as an inclined surface inclined inward and downward, so that it is more advantageous that at least the pressure of the chamber C1 is transmitted to the right below of the upright portion 142 in the process of being transmitted to the radial outside more and is converted into a radial force as little as possible. Preferably, the included angle between the inclined plane and the horizontal plane is 30-60 degrees, and further preferably, the included angle between the inclined plane and the horizontal plane is 45 degrees, and the thickness of the local thickening structure, which is perpendicular to the inclined plane, is not less than 1.5mm.

In the present invention, the pressures of the chambers C1 and C2 largely cancel each other out, so that the pressing force of the flexible membrane portion directly below the chamber C2 is greater than the pressing force of the flexible membrane directly below the upright portion 142, although a part of the force of the chamber C1 is transmitted obliquely downward through the inclined surface and acts on the upright portion 142 and further acts on the flexible membrane directly below the upright portion 142, but such a force component still cannot solve the situation that the pressure may be insufficient below the upright portion 142, therefore, it is necessary to fully utilize the distance L1 between the inner edge of the spacer plate 146 and the inner edge of the first horizontal extension portion 145, which is determined by the distance L1 shown in fig. 3, the magnitude of the force transmitted directly below the upright portion 142 by the chambers C1 and/or C2 during the pressurization is determined, specifically, the magnitude of the force L1 and the magnitude of the force transmitted directly below the upright portion 142 during the pressurization are considered to be substantially equal to the length of the spacer plate 146 mm, and the length of the spacer plate is preferably limited to be greater than 4mm, and the length of the spacer plate 146 should be bent in proportion to the length; alternatively, the effect of such a difference in horizontal extension length can also be equivalently understood as that the difference in tension/pressure between the intermediate partition plate 146 and the first horizontal extension portion 145 during the pressurization of the chambers C1 and C2 can be equivalently regarded as a portion of the flexible membrane transmitted to the portion directly below the upright portion 142, and the difference in tension/pressure is mainly generated due to the difference in distance of the intermediate partition plate 146 from the first horizontal extension portion 145 extending horizontally in the radial direction.

Meanwhile, the inner edge of the partition plate 146 is farther from the center position of the bottom plate portion 141 than the inner edge of the second horizontally extending portion 147, and the distance between the inner edge of the partition plate 146 and the inner edge of the second horizontally extending portion 147 is L2, as shown in fig. 3. The distance between the inner edge of the partition plate 146 and the inner edge of the second horizontal extension 147 is 2mm to 10mm, and preferably, the distance between the inner edge of the partition plate 146 and the inner edge of the second horizontal extension 147 is 3mm to 5mm. So set up, on the one hand be favorable to nimble control chamber C2's pressure, on the other hand also be favorable to flexible membrane 14 corresponding to the design and the installation of adapting unit.

Further, the partition plate 146 includes a partition plate first horizontal portion 146a horizontally and inwardly formed from the inner surface of the edge side wall, a protrusion portion 146b formed by being arched upward from an end of the partition plate first horizontal portion 146a, and a partition plate second horizontal portion 146c horizontally and inwardly formed from an end of the protrusion portion 146b, as shown in fig. 4, which are integrally formed.

In fig. 4, the first horizontal portion 146a of the partition plate and the second horizontal portion 146c of the partition plate are located on the same horizontal plane, and the protruding portion 146b extends vertically upward from the end of the first horizontal portion 146a of the partition plate, and then extends vertically downward after passing through an arc transition. Further, the length of the vertical upward extension is equal to the length of the vertical downward extension.

As an aspect of the present embodiment, the wall thickness of the first horizontal portion 146a, the convex portion 146b, and the second horizontal portion 146c of the partition plate are the same. In another aspect of this embodiment, the wall thickness of the protruding portion 146b may be smaller than the wall thicknesses of the first horizontal portion 146a and the second horizontal portion 146c of the partition plate, for example, the wall thickness of the protruding portion 146a is 30% to 60% of the wall thickness of the other portions of the partition plate 146, so as to enhance the flexibility of the partition plate 146.

As a variation of this embodiment, a plurality of the protrusions 146b may be provided, which are spaced at upper and lower sides of the plane of the first horizontal portion 146a of the partition plate, to facilitate pressure adjustment of the chambers C1 and C2.

As another embodiment of the present invention, the partition plate second horizontal portion 146c is positioned at an upper side of the partition plate first horizontal portion 146a, as shown in fig. 5. The protruding portion 146b is formed by extending the end portion of the first horizontal portion 146a of the partition plate in an upward and inward inclined manner and then extending in a downward and inward inclined manner, and the included angle between the upward and inward inclined extending section and the horizontal plane is larger than the included angle between the downward and inward inclined extending section and the horizontal plane. Preferably, the angle between the upwardly and inwardly inclined extension and the horizontal plane is 0.5 to 10 degrees greater than the angle between the downwardly and inwardly inclined extension and the horizontal plane, so as to reduce the pulling of the spacer plates 146 on the upright portions 142 and improve the accuracy of the load application of the edge portions of the flexible film.

Further, the height difference between the bottom surface of the second horizontal portion 146c of the partition plate and the bottom surface of the first horizontal portion 146a of the partition plate is 3mm to 10mm. Preferably, the height difference between the bottom surface of the second horizontal portion 146c of the partition plate and the bottom surface of the first horizontal portion 146a of the partition plate is 4mm to 6mm.

Fig. 6 is a schematic view of another embodiment of the edge portion of the flexible film 14 according to the present invention, in which the partition plate 146 extends horizontally and inwardly from the inner surface of the edge sidewall and then extends upwardly and inwardly in an inclined manner, an included angle between the upwardly and inwardly inclined extension section 146d and the horizontal plane is 5 to 45 °, and a sealing connection portion is provided at an end of the upwardly and inwardly inclined extension section 146d to be in sealing connection with the annular platen 15. Preferably, the upwardly and inwardly inclined extension 146d is angled 30 from the horizontal. As an aspect of this embodiment, the wall thickness of the upwardly and inwardly inclined extension section 146d is 30% to 70% of the wall thickness of the other portion of the partition plate 146, so as to improve the pressure regulation capability of the chamber C1, thereby accurately controlling the polishing pressure at the edge portion of the flexible membrane 14 and controlling the material removal rate at the edge region of the substrate.

Fig. 7 is a schematic view of an edge portion of the flexible film 14 according to the present invention, wherein the bending portion 143 is provided with two folds (35103) to improve flexibility of the edge portion of the flexible film 14. It is understood that other numbers of the folds (35103) can be disposed on the bending portion 143, which can be weighted according to the structural and functional requirements of the carrier head.

Fig. 8 shows a deformation diagram of the upright portion 142 of the prior art flexible membrane 14' in a pressurized state. Due to the wall thickness of the spacer 146 not being properly arranged with respect to the wall thickness of the rest of the flexible membrane 14, when the chamber C1 is inflated and pressurized, the upright portion 142 is pulled inwardly, so that the upright portion 142 is inclined inwardly, which is indicated by the dashed line in fig. 8 for the inwardly inclined upright portion 142. The inclination of the upstanding portion 142 affects the normal loading of the flexible membrane 14, particularly the polishing pressure in the edge region of the wafer. In some embodiments of the present invention, the wall thickness of the spacer plate 146 is 1/3 to 1 of the thickness of the upright portion 142, so as to reduce the pulling of the spacer plate 146 on the upright portion 142, improve the accuracy of the pressure loading of the edge portion of the flexible film 14, and improve the uniformity of the wafer polishing.

In the embodiment shown in fig. 1, a portion of the upper surface of the first horizontal extension portion 145 is pressed by the carrier plate 13, which is advantageous for adjusting the degree of expansion of the chamber C1 when pressurized. Specifically, the partial structure can be matched with the structure of the bent portion 143, so that the accuracy of pressure adjustment of the flexible membrane 14 is improved. Preferably, 1/3-2/3 of the upper surface of the first horizontal extension 145 is pressed by the carrier tray 13.

Meanwhile, the invention also discloses polishing equipment, which has a schematic structural diagram as shown in FIG. 9. The polishing apparatus 1000 includes a polishing disk 100, a polishing pad 200, a carrier head 300 shown in fig. 1, a dresser 400, and a liquid supply portion 500; the polishing pad 200 is disposed on the upper surface of the polishing disc 100 and rotates along the axis Ax therewith; a horizontally movable carrier head 300 disposed above the polishing pad 200, the lower surface of which receives a substrate to be polished; the dresser 400 includes a dresser arm and a dresser head, which are disposed at one side of the polishing disc 100, 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 300 presses the surface of the substrate to be polished against the surface of the polishing pad 200, and the carrier head 300 performs a rotation motion and a reciprocating motion along the radial direction of the polishing disc 100, so that the surface of the substrate contacting the polishing pad 200 is gradually polished; meanwhile, the polishing pad 100 rotates, and the liquid supply part 500 sprays polishing liquid onto the surface of the polishing pad 200. The substrate is rubbed against the polishing pad 200 by the relative movement of the carrier head 300 and the polishing pad 100 under the chemical action of the polishing liquid to perform polishing.

The polishing solution composed of submicron or nanometer abrasive particles and a chemical solution flows between the substrate and the polishing pad 200, the polishing solution 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 substrate and the polishing pad 200, chemical components in the liquid and the substrate generate chemical reaction to convert insoluble substances into soluble substances, then the chemical reactants are removed from the surface of the substrate through micro-mechanical friction of the abrasive particles and dissolved in the flowing liquid to be taken away, namely surface materials are removed in an alternating process of chemical film formation and mechanical film removal to realize surface planarization treatment, so that the purpose of global planarization is achieved.

During chemical mechanical polishing, the dresser 400 is used to dress and activate the topography of the polishing pad 200. The dresser 400 is used to remove foreign particles remaining on the surface of the polishing pad, such as abrasive particles in the slurry and waste material released from the surface of the substrate, and to planarize the surface deformation of the polishing pad 200 caused by abrasion, thereby ensuring the uniformity of the surface topography of the polishing pad 200 during polishing and stabilizing the removal rate of polishing.

The drawings accompanying this specification are for the purpose of illustrating the concepts of the invention and are not necessarily to scale, the drawings being schematic representations of the shapes of the parts and their interrelationships. 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

1. A flexible membrane for chemical mechanical polishing, comprising:

a bottom plate portion for receiving a substrate;

an annular edge side wall having a vertical portion extending upward along a peripheral edge of the bottom plate portion, a bent portion provided on an upper side of the vertical portion, and a first horizontal extending portion extending horizontally inward from an upper end of the bent portion;

the inner side wall is concentrically and adjacently arranged with the edge side wall, and the top end of the inner side wall is provided with a second horizontal extending part which is bent to the inner side and horizontally extends;

and a partition plate extending radially inward from an inner surface of the rim side wall, the partition plate having a wall thickness smaller than a wall thickness of the bottom plate portion, an inner edge of the partition plate being closer to a center position of the bottom plate portion than an inner edge of the first horizontally extending portion;

the bending part comprises a first bending part which is bent upwards and inwards from the vertical part and a second bending part which is bent upwards and outwards from the first bending part, and the included angle between the first bending part and the horizontal plane is smaller than that between the second bending part and the horizontal plane; the inner side of the joint of the bottom plate part and the upright part is provided with a groove part, and the thickness of the edge part of the bottom plate part is gradually reduced from inside to outside; the partition plate comprises a first horizontal part of the partition plate, a bulge part and a second horizontal part, wherein the first horizontal part of the partition plate is horizontally and inwardly formed from the inner surface of the edge side wall, the bulge part is formed by arching the end part of the first horizontal part of the partition plate towards the upper side, and the second horizontal part of the partition plate is horizontally and inwardly formed from the end part of the bulge part; the first horizontal part of the partition plate and the second horizontal part of the partition plate are positioned on the same horizontal plane.

2. The flexible membrane of claim 1, wherein the spacer is formed to extend horizontally inwardly from the inner surface of the edge sidewall.

3. The flexible membrane of claim 2, wherein the spacer plate has a wall thickness of 1/3 to 1 of a wall thickness of the bottom plate portion.

4. A carrier head comprising the flexible membrane for chemical mechanical polishing according to any one of claims 1 to 3.

5. A polishing apparatus comprising the carrier head of claim 4.