WO2022166776A1

WO2022166776A1 - Flexible membrane, bearing head and planarization apparatus for chemical mechanical planarization

Info

Publication number: WO2022166776A1
Application number: PCT/CN2022/074444
Authority: WO
Inventors: 赵德文; 王宇; 路新春
Original assignee: 华海清科股份有限公司
Priority date: 2021-02-03
Filing date: 2022-01-27
Publication date: 2022-08-11
Also published as: CN112847127B; CN112847127A

Abstract

A flexible membrane for chemical mechanical planarization, the flexible membrane comprising a bottom plate part (141) for receiving a substrate; an annular edge side wall, the edge side wall being provided with an upright part (142), which is formed by means of extending upwards along the peripheral edge of the bottom plate part, a bent part (143), which is arranged on the upper side of the upright part, and a first horizontal extension part (145), which is formed by means of horizontally extending inwards from the upper end of the bent part; and an inner side wall (144), which is arranged concentric with and adjacent to the edge side wall, wherein the top end of the inner side wall is provided with a second horizontal extension part (146), which is bent inwards and horizontally extends. The bent part comprises a first bent part (143a), which is bent upwards and inwards and extends from the upper end of the upright part, and a second bent part (143b), which is bent upwards and outwards and extends from the first bent part; and an included angle between the first bent part and a horizontal plane is not equal to an included angle between the second bent part and the horizontal plane. Further disclosed is a bearing head for chemical mechanical planarization, the bearing head comprising the flexible membrane. Further disclosed is a planarization apparatus, comprising the bearing head. An edge chamber is structurally optimized, such that the problem(s) of over-planarization and/or under-planarization of the edge of the substrate are/is solved to a certain extent; and the accuracy of membrane thickness measurement during a planarization process is improved, such that the accuracy of planarization process control and planarization results are improved.

Description

A flexible membrane, carrier head and polishing equipment for chemical mechanical polishing

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 technique

The integrated circuit industry is the core of the information technology industry and plays a key role in the process of boosting the transformation and upgrading of the manufacturing industry to digitalization and intelligence. A chip is the carrier of an integrated circuit, and chip manufacturing involves process processes such as chip design, wafer manufacturing, wafer processing, electrical measurement, cutting, packaging, and testing. Among them, chemical mechanical polishing belongs to the wafer manufacturing process.

Chemical mechanical polishing (Chemical Mechanical Planarization, CMP) is a global planarization of ultra-precision surface processing technology. In chemical mechanical polishing, the wafer is usually attracted to the bottom surface of the carrier head. The side of the wafer with the deposited layer is pressed against the upper surface of the polishing pad. At the same time, the polishing liquid is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the wafer can complete the chemical mechanical polishing of the wafer under the combined action of chemical and mechanical.

In the prior art CMP carrier head, the multi-chamber diaphragm has five pressure-adjustable chambers that act on different annular regions of the substrate respectively. The five chambers cooperate with each other to perform the pressure polishing operation, which can be compared with having only one chamber. A carrier head with or less than five chambers improves polishing uniformity and consistency. In order to polish the substrate more uniformly, the industry has consistently pursued dividing more chambers, such as six chambers with adjustable pressure, for the diaphragm used for the substrate operation in the carrier head.

In addition, while increasing the number of chambers, it is also necessary to minimize the "edge effect" (the wafer edge polishing is difficult to control, and the rotation speed is higher than the inner side of the wafer, resulting in over-polishing). The three chambers are structurally optimized to enhance the regulation effectiveness, stability, and accuracy of this region.

In conclusion, the industry hopes to provide a chemical-mechanical carrier head to solve the problems of polishing uniformity, consistency, edge effect, loading effectiveness, loading reliability, loading accuracy, etc., especially to solve the over-polishing and/or under-polishing of the edge portion of the substrate However, these problems usually affect each other, which makes the design of the bearing head difficult to balance.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a flexible membrane, a carrier head, and a polishing device for chemical mechanical polishing, which aim to solve one of the technical problems existing in the prior art at least to a certain extent.

According to one aspect of the present invention, the present invention provides a flexible film for chemical mechanical polishing, comprising: a circular bottom portion for receiving a substrate; an upright portion formed by vertically extending the peripheral edge of the bottom plate portion upward, a bent portion disposed on the upper side of the upright portion, and a first horizontal extension portion formed horizontally extending from the upper end of the bent portion to the inner side of the bottom plate portion , the bottom of the edge side wall is integrally formed with the bottom plate part; and a circular vertical inner side wall is arranged concentrically adjacent to the edge side wall, and the inner side wall has a bent towards the bottom plate at its top end a second horizontal extension part horizontally extending from the inner side of the inner side wall, the inner side wall is integrally formed with the bottom plate part at the bottom thereof; A second bending portion is bent upward and outward from the first bending portion, and the included angle between the first bending portion and the horizontal plane is not equal to the included angle between the second bending portion and the horizontal plane.

As a preferred embodiment, the included angle between the first bending portion and the horizontal plane is smaller than the included angle between the second bending portion and the horizontal plane.

As a preferred embodiment, the included angle between the first bending portion and the horizontal plane is 1-10° smaller than the included angle between the second bending portion and the horizontal plane.

As a preferred embodiment, the bent portion extends outward not beyond the circumferential outer surface of the upright portion.

As a preferred embodiment, the angle between the first bending portion and the horizontal plane is 1-25°.

As a preferred embodiment, the horizontal projection of the inwardly bent portion of the bent portion does not exceed the inner edge of the first horizontal extension portion.

As a preferred embodiment, it further includes a spacer plate extending radially inward from the inner surface of the edge side wall, and the inner edge of the spacer plate is farther from the center of the bottom plate portion than the inner edge of the second horizontally extending portion. Location.

As a preferred embodiment, the horizontal distance between the inner edge of the partition plate and the inner edge of the second horizontally extending portion is 2-10 mm.

According to another aspect of the present invention, the present invention provides a carrier head for chemical mechanical polishing, comprising the flexible membrane for chemical mechanical polishing described above.

According to yet another aspect of the present invention, the present invention provides a polishing apparatus comprising the above-described carrier head for chemical mechanical polishing.

The beneficial effects of the present invention include: enhancing the regulation effectiveness, stability, accuracy, etc. of the region by optimizing the structure of the edge chamber and providing a chemical mechanical polishing flexible film, a carrier head and a polishing equipment to solve the polishing uniformity , consistency, edge effect, loading effectiveness, loading reliability, loading has been determined and other issues, especially to a certain extent to solve the problem of over-throwing and/or under-throwing of the edge part of the substrate; in addition, without affecting the load On the premise of the operation function and reliability of the head and chemical mechanical polishing equipment, the accuracy of the film thickness measurement during the polishing process can be improved and improved, so as to improve the polishing process control and the accuracy of the polishing results.

Description of drawings

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

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

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

FIG. 3 is a partial enlarged view of the edge portion of the flexible film 14 in FIG. 2;

4 is a schematic diagram of the deformation of the bending portion 143 when the flexible film 14 of the present invention is loaded;

Fig. 5 shows the material removal rate contour line of the wafer edge portion corresponding to different included angle differences;

6 is a schematic diagram of another embodiment of the edge portion of the flexible film 14 according to the present invention;

FIG. 7 is a schematic structural diagram of the polishing apparatus 1000 of the present invention;

FIG. 8 is a material removal rate profile line corresponding to the prior art and the present invention.

Detailed ways

The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention, used to illustrate the concept of the present invention; these descriptions are all explanatory and exemplary, and should not be construed as limiting the embodiments of the present invention and the protection scope of the present invention . In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims of the present application and the description thereof, and these technical solutions include adopting any modifications made to the embodiments described herein. Obvious alternative and modified technical solutions.

The accompanying drawings in the present specification are schematic diagrams to assist in explaining the concept of the present invention, and schematically show the shapes of various parts and their mutual relationships. It should be understood that, in order to clearly represent the structures of the various components of the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to denote the same parts in the drawings.

Chemical mechanical polishing equipment is referred to as polishing equipment, which generally includes a polishing disc, a polishing pad, a liquid supply device, a dressing device, a detection device, a control device, etc., and its composition scheme has been fully embodied in the prior art as the prior art. It is not repeated here, but it should be understood that the chemical mechanical polishing equipment according to the present invention also includes necessary parts and components for operations such as polishing discs, polishing pads, liquid supply devices, dressing devices, detection devices, and control devices. The following mainly introduces the structure and function of the core element carrier head in the chemical mechanical polishing apparatus according to the present invention, and the carrier head described below can be applied in the chemical mechanical polishing apparatus according to the present invention. It should be pointed out that, unless otherwise specified, the inward and radially inwards mentioned in this embodiment refer to inwards along the radial direction of the bottom plate portion 141 , and the outwards and radially outwards refer to along the radial direction of the bottom plate portion 141 . The radial direction of the bottom plate portion 141 is outward; and any of the following technical features regarding the carrier head and the flexible membrane can be combined and/or formed separately, as long as these features and/or the combination of features can improve the workability of chemical mechanical polishing and process results; in addition, if the terms in the present invention are inconsistent with national or international standards or previous or subsequent applications, they should be interpreted and understood according to the actual function of the part, component, component or assembly, etc. It should not be taken as a basis for limiting the protection scope of the present invention. In the present invention, "chemical mechanical polishing (Chemical Mechanical Polishing, CMP)" is also referred to as "chemical mechanical planarization (Chemical Mechanical Planarization, CMP)", wafer (Wafer) is also referred to as substrate (Substrate), material removal rate ( Material Remove Rate, MRR), its meaning and actual effect are equivalent.

As shown in FIG. 1 , the present invention provides a chemical mechanical polishing head 300. For the convenience of description, the chemical mechanical polishing head is hereinafter referred to as a carrier head for short. The bearing head 300 includes a gimbal 11, a connecting plate 12, a bearing plate 13, a flexible membrane 14, an annular annular pressure plate 15, a retaining ring 16, a first clamping ring 18, a second clamping ring 19, and a third clamping ring The ring 20, the annular elastic membrane 21, etc., wherein the coupling disc 12 is connected to the external drive shaft to drive the entire carrier head 300 to move and/or rotate. Specifically, the second clamping ring 19 and the third clamping ring 20 clamp the outer and inner edges of the elastic mold 21 to the bearing plate 13 and the connecting plate 12, respectively, so that the bearing plate 13 can rotate together with the connecting plate 12. .

A gimbal 11 having a central shaft portion, a chassis portion, a peripheral wall portion and a flange portion is coaxially disposed with the connecting shaft plate 12, wherein the shaft portion is slidably inserted into the central shaft hole of the connecting shaft plate 12 and can be vertically arranged therein. Moving in the straight direction, the flange portion of the gimbal 11 is coupled to the central stepped hole of the carrier plate 13 by means of a washer 17, a first clamping ring 18 and a bolt not shown, so that the carrier plate 13 can rotate together with the gimbal 11 and/or Move vertically.

The flexible film 14 is clamped to the lower part of the carrier plate 13 by the annular platen 15 and can move and/or rotate together with the platen 13; the flexible film 14, the annular platen 15 and the platen 13 cooperate to form C1, C2, The seven adjustable pressure chambers C3, C4, C5, C6, and C7 can be adjusted separately. Although not shown, it should be understood that the carrier head 300 is provided with a plurality of gas passages that can be coupled to the external air passages, and these gas passages pass through the coupling plate 12 , the carrier plate 13 , and the annular pressure plate 15 , respectively, and communicate with each other. to these adjustable pressure chambers, so as to adjust their pressure by introducing gas into these chambers or extracting gas from these chambers; The through holes extending parallel to the shaft portion are used to adjust the pressure of the adjustable pressure chamber C8 to adjust the displacement of the bearing plate 13 and the flexible film 14 relative to the shaft connection plate 12 in the vertical direction.

According to a schematic diagram of the structure of the flexible film 14 of the present invention, as shown in FIG. 2 , the flexible film 14 includes a circular bottom plate portion 141 and an annular edge side wall, and the edge side wall includes a vertical upward direction along the bottom plate portion 141 . The extending upright portion 142, the bent portion 143 connected to the top of the upright portion 142, and the first horizontal extension portion 145 formed horizontally extending from the upper end of the bent portion 143 inwardly, the bottom of the edge side wall and the bottom plate portion 141 form one body.

The free end of the first horizontally extending portion 145 has a sealing portion 145a extending vertically downward toward the inner side. In order to enhance the rigidity of the upright portion 142, it can more effectively transmit the action downward toward the inner side along the vertical direction. Force, the outer surface of the upright portion 142 is formed with an annular groove for arranging the outer support ring of the flexible membrane, the groove extends radially toward the inner side and its thickness is not more than half of the thickness of the upright portion 142, so that the flexibility The outer membrane support ring can be stably clamped in the groove, and the flexible membrane outer support ring and the groove extend upward to a position close to the lower end of the bending portion 143 and extend downward to a position of 0.5 mm to 4 mm from the upper surface of the bottom plate portion 141 In particular, after the flexible membrane outer support ring is snapped into the groove, it extends in the radial direction to no more than 2 mm from the radially outer surface of the upright portion 142 to avoid the formation of polishing liquid crystals in the vicinity of the lower portion of the flexible membrane outer support ring.

Further, an annular groove extending radially toward the inside and outside is formed on the inner side of the joint root of the upright portion 142 and the bottom plate portion 141, and its function includes enhancing the degree of freedom of the root portion of the upright portion 142 of the edge side wall to prevent stress concentration and localization. to a certain extent, the removal rate regulation effect of the edge area of the substrate is relieved; in order to further strengthen the rigidity of the upright portion 142 so that the pressure of the upper chamber thereof can be more transmitted downward to the area directly below it, in view of the inconvenience If a flexible membrane outer support ring with an excessive thickness is provided, a flexible membrane inner support ring may be provided on the inner surface of the upright portion 142 .

In the embodiment shown in FIG. 2 , the flexible film 14 further includes an inner side wall 144 concentrically adjacent to the edge side wall. The inner side wall 144 has a second horizontal extension portion 147 at its top end that is bent and horizontally extended inward. The wall 144 is integrally formed with the bottom plate portion 141 at its bottom.

The flexible membrane 14 further includes a spacer plate 146 extending radially inward from the inner surface of the edge side wall, and the outer end surface of the spacer plate 146 is closer to the center of the bottom plate portion 141 than the inner edge of the first horizontally extending portion 145 , so as to The overall flexibility of the flexible membrane 14 is increased. In the present invention, the inner edge refers to the portion of the rib extending toward the inner side of the flexible film 14 and close to the center of the flexible film.

FIG. 3 is a partial enlarged view of the edge portion of the flexible film 14 in FIG. 2 , a groove portion 141 a is provided on the inner side of the intersection of the bottom plate portion 141 and the upright portion 142 . That is, the thickness of the edge portion of the bottom plate portion 141 gradually decreases from the inside to the outside, so as to regulate the polishing removal rate of the local area of the edge of the substrate. The bent portion 143 includes a first bent portion 143a that is bent upward and inwardly extended from the upper end of the upright portion 142 and a second bent portion 143b that is bent upward and outward from the first bent portion 143a. The included angle θ between the folded portion 143a and the horizontal plane is not equal to the included angle β between the second folded portion 143b and the horizontal plane. In this way, the bending portion 143 cooperates with the groove portion 141a on the edge of the bottom plate portion 141 , which is beneficial to improve the flexibility of the bending portion 143 , so that the internal pressure in the chamber C1 can be adjusted more freely.

As an embodiment of the present invention, the included angle θ between the first bending portion 143a and the horizontal plane is smaller than the included angle β between the second bending portion 143b and the horizontal plane. The first horizontal extension portion 145 is connected with the carrier plate 13 , the bending portion 143 is connected with the first horizontal extension portion 145 , and the included angle of the bending portion 143 is set, which is beneficial to improve the uniformity of the pressure deformation of the bending portion 143 , making the flexibility The polishing pressure regulation of the edge portion of the membrane 14 is more precise, so as to adjust the material removal rate corresponding to the edge portion of the substrate and improve the uniformity of the global polishing of the substrate.

Further, the horizontal projection of the inwardly bent portion 143 does not exceed the inner edge of the first horizontal extension portion 145 , that is, the level of the inwardly bent junction of the first bent portion 143a and the second bent portion 143b The position does not exceed the inner edge of the first horizontal extension 145 . When the flexible film 14 is pressurized, the bent portion 143 moves outwards substantially horizontally, so as to ensure the stable deformation of the bent portion 143 during pressurization.

As another embodiment of the present invention, the included angle θ between the first bending portion 143a and the horizontal plane is 1-10° smaller than the included angle β between the second bending portion 143b and the horizontal plane. Preferably, the included angle θ between the first bending portion 143a and the horizontal plane is 3-8° smaller than the included angle β between the second bending portion 143b and the horizontal plane, so as to prevent the chamber C1 from bulging excessively and turning over. If the bent portion 143 of the flexible membrane 14 is everted, the everted bent portion 143 contacts the retaining ring, which interferes with the loading of polishing pressure, and even affects the service life of the flexible membrane 14 . FIG. 4 shows the corresponding deformation of the bending portion 143 when the flexible film 14 is pressurized. If the structure of the bending portion 143 is not properly set, the eversion situation indicated by the dotted line will occur. Therefore, it is necessary to strictly control the inclination of the first bent portion 143a and the second bent portion 143b, so that the bent portion 143 of the flexible film 14 swells outward without everting. FIG. 4 uses the center line to show a situation in which the bent portion 143 is bulged to the outside. In this embodiment, the bent portion 143 formed by the first bent portion 143a and the second bent portion 143b is slightly bulged to the outside. . When the chamber C1 expands, the bent portion 143 moves substantially in the horizontal direction, so as to reduce the influence of the pressurization of the chamber C1 on the upright portion 142 and improve the accuracy of pressure loading.

The structure of the bent portion 143 shown in FIG. 3 is also beneficial to improve the accuracy of loading the edge portion of the flexible film 14. The included angle difference between the included angle θ and the included angle β is 1-10°, preferably, the included angle difference is 3-8°.

FIG. 5 shows the material removal rate profile of the wafer edge portion corresponding to different included angle differences. When the angle difference is greater than 5°, the material removal rate contour line at the edge of the wafer has a valley value around 145mm; when the angle difference is 5-10°, the corresponding material removal rate at the wafer edge The valley value of the contour line is higher than the corresponding valley values of the other two positions, that is, the material removal rate at the position around 145mm of the wafer is closer to the material removal rate at the center of the wafer; and at the position between 145mm and 150mm, the material removal rate The extreme value corresponding to the rate is reduced, which is beneficial to the uniformity of polishing.

Further, the included angle θ between the first bending portion 143a and the horizontal plane is 1-25°, preferably, the included angle θ between the first bending portion 143a and the horizontal plane is 3-15°, which can avoid the first bending The portion 143a abuts against the spacer plate 146 to affect the normal loading of the flexible film 14 . The angle β between the second bending portion 143b and the horizontal plane is 5-45° to avoid the application of polishing pressure of the carrier head due to the contact between the first horizontal extension portion 145 and the bottom surface of the carrier plate 13 when the flexible film 14 is loaded.

In the embodiment shown in FIG. 1 , a part of the upper surface of the first horizontal extension part 145 is pressed by the carrier plate 13 , which is beneficial to adjust the degree of expansion of the chamber C1 when pressurized. Specifically, this part of the structure can cooperate with the structure of the bending portion 143 to improve the accuracy of the pressure adjustment of the flexible membrane 14 . Preferably, 1/3-2/3 of the upper surface of the first horizontal extension part 145 is pressed by the carrying tray 13 .

As an embodiment of the present invention, the included angle formed by the first bending portion 143 a and the second bending portion 143 b needs to be greater than 30°, so that the eversion of the bending portion 143 can be avoided to ensure the overall use of the flexible film 14 performance.

As another aspect of this embodiment, the wall thickness of the bending portion 143 is smaller than the thickness of the bottom plate portion 141 . The flexibility of elastic deformation of the portion 143 .

In the embodiment shown in FIG. 2 , the bent portion 143 does not extend beyond the circumferential outer surface of the upright portion 142 to ensure that the load of the chamber C1 is completely applied to the bottom portion 141 of the flexible membrane 14 . That is, the load of the edge portion of the flexible film 14 completely acts on the edge region of the substrate without generating an invalid load. Preferably, the bent portion 143 can be offset toward the inner side of the flexible film 14, for example, the distance between the bent portion 143 and the outer circumferential surface of the upright portion 142 can be 0.5mm˜3mm, so as to adjust the polishing pressure at a certain position on the edge of the substrate , to adjust the material removal rate for that location.

In FIG. 3, the partition board 146 includes a partition board first horizontal portion 146a, a partition board corrugated portion 146b, a partition board lower scallop portion 146c and a partition board second horizontal portion 146d, which are directed radially from the inner surface of the edge side wall It is formed by extending inwardly, and the height of the corrugated portion 146b on the partition plate is greater than the height of the lower shell portion 146c of the partition plate. Preferably, the height of the corrugated portion 146b on the partition plate toward the upper side is 1.5 to 3 times the height of the lower scallop portion 146c of the partition plate bent downward, so that the second horizontal portion 146d of the partition plate is located on the side of the first horizontal portion 146a of the partition plate. On the upper side, the controllability of the load inside the chamber C1 is improved.

In order to improve the stress on the root of the spacer plate 146 and thereby improve the accuracy and reliability of the downward pressure transmission from the upright portion 142, it is preferable to form a local thickening on the upper surface of the root region of the spacer plate 146 that is combined with the upright portion 142. , the section of the local thickening structure is formed as a slope inclined to the inner side and downward, which is at least more favorable for the pressure of the chamber C1 to be more transferred to the directly below the upright portion 142 in the process of transferring to the radial outer side. Convert as little as possible to radial force. Preferably, the angle between the inclined plane and the horizontal plane is 30° to 60°, and more preferably, the angle between the inclined plane and the horizontal plane is 45°, and the thickness of the local thickening structure perpendicular to the inclined plane should not be less than 1.5mm. .

In the present invention, the pressures of the chambers C1 and C2 will cancel each other to a large extent, so that the downward pressure force of the flexible membrane portion directly under the chamber C2 is greater than the downward pressure force of the flexible membrane directly under the upright portion 142, although the chamber C1 A part of the force will be transmitted downward through the inclined plane and act on the upright portion 142 and further act on the flexible film directly below it, but such a force component still cannot solve the possible lack of pressure below the self-supporting portion 142. To this end, it is necessary to make full use of the outward pressure acting on the root of the partition plate 146 when the partition plate 146 is stretched during the pressurization process of the chamber C1 to transmit to the upright portion 142 and make its component act directly below the upright portion 142. Therefore, the partition plate The distance L1 between the inner edge of 146 and the inner edge of the first horizontal extension portion 145 is particularly critical. This distance L1 shown in FIG. 3 determines that the chambers C1 and/or C2 are transferred to the upright portion 142 during the pressurization process. The magnitude of the force directly below, specifically, the size of this distance L1 is roughly proportional to the magnitude of the force transmitted directly below the upright portion 142, but considering that the partition plate 146 needs to be placed too bent downward and the inner side wall If interference occurs between other structures, the horizontal projection length of the spacer plate 146 should also be limited. Generally speaking, the length of L1 should be greater than 2 mm, preferably greater than 4 mm; or, the effect of such a difference in horizontal extension length can also be understood equivalently. Therefore, in the process of pressurizing the chambers C1 and C2, the tension/pressure difference between the partition plate 146 and the first horizontal extension part 145 can be equivalently regarded as the part transmitted to the flexible membrane directly below the upright part 142, The main reason for such a tension difference/pressure difference is the difference in the distance between the spacer plate 146 and the first horizontal extending portion 145 extending horizontally in the radial direction.

Meanwhile, the inner edge of the partition plate 146 is farther from the center of the bottom plate portion 141 than the second horizontal extension portion 147, and the distance between the inner edge of the partition plate 146 and the inner edge of the second horizontal extension portion 147 is L2, as shown in FIG. 3 . Show. The distance between the inner edge of the partition plate 146 and the inner edge of the second horizontal extension part 147 is 2mm-10mm, preferably, the distance between the inner edge of the partition plate 146 and the inner edge of the second horizontal extension part 147 is 3mm -5mm. This arrangement is beneficial to flexibly control the pressure of the chamber C2 on the one hand, and is also beneficial to the design and installation of the corresponding connecting parts of the flexible membrane 14 on the other hand.

6 is a schematic diagram of another embodiment of the edge portion of the flexible film 14 according to the present invention. In this embodiment, the inner side wall 144 is arranged perpendicular to the bottom plate portion 141 , the inner side wall 144 , the second horizontal extension portion 147 , the spacer 146 and the ring The shaped platen 15 forms a chamber C2 ; the chamber C1 transmits pressure to the chamber C2 to regulate the pressure of the edge portion of the flexible membrane 14 .

At the same time, the present invention also discloses a polishing device, the schematic diagram of which is shown in FIG. 7 . The polishing apparatus 1000 includes a polishing disc 100, a polishing pad 200, a carrier head 300 shown in FIG. 1, a dresser 400 and a liquid supply part 500; the polishing pad 200 is disposed on the upper surface of the polishing disc 100 and rotates along the axis Ax together with it; it can be horizontal The movable carrier head 300 is disposed above the polishing pad 200, and its lower surface receives the substrate to be polished; the trimmer 400 includes a trimming arm and a trimming head, which are disposed on one side of the polishing disc 100, and the trimming arm drives the rotating trimming head to swing to The surface of the polishing pad 200 is trimmed; the liquid supply part 500 is arranged on the upper side of the polishing pad 200 to spread the polishing liquid on the surface of the polishing pad 200 .

During the polishing operation, the carrier head 300 presses the to-be-polished surface of the substrate against the surface of the polishing pad 200, and the carrier head 300 rotates and reciprocates along the radial direction of the polishing disc 100 so that the surface of the substrate in contact with the polishing pad 200 is gradually polished. At the same time, the polishing disc 100 rotates, and the liquid supply part 500 sprays the polishing liquid on the surface of the polishing pad 200 . Under the chemical action of the polishing liquid, the substrate and the polishing pad 200 are rubbed by the relative movement of the carrier head 300 and the polishing disk 100 to perform polishing.

The polishing liquid composed of sub-micron or nano abrasive particles and chemical solution flows between the substrate and the polishing pad 200 , and the polishing liquid is evenly distributed under the action of the transmission of the polishing pad 200 and the centrifugal force of rotation, so that the polishing liquid is evenly distributed between the substrate and the polishing pad 200 A layer of liquid film is formed, and the chemical components in the liquid react with the substrate to convert insoluble substances into soluble substances, and then these chemical reactants are removed from the surface of the substrate by the micro-mechanical friction of abrasive particles and dissolved into the flowing liquid. Take away, that is, to remove the surface material in the alternate process of chemical film formation and mechanical film removal to achieve surface planarization, so as to achieve the purpose of global planarization.

The conditioner 400 is used to condition and activate the surface topography of the polishing pad 200 during chemical mechanical polishing. The use of the conditioner 400 can remove the impurity particles remaining on the surface of the polishing pad, such as the abrasive particles in the polishing liquid and the waste material falling off the surface of the substrate, etc., and can also flatten the surface deformation of the polishing pad 200 caused by grinding, ensuring that The uniformity of the surface topography of the polishing pad 200 during polishing, in turn, keeps the polishing removal rate stable.

8 is the material removal rate contour line of the chemical mechanical polishing equipment of the prior art and the substrate of the chemical mechanical polishing equipment corresponding to the present invention, wherein the solid line is the material removal contour line corresponding to the prior art. The linear velocity of the edge portion is higher than that of the center portion, and the edge portion of the substrate is more easily combined with the polishing liquid, so that the removal rate of the edge portion of the substrate is greater than that of the center portion of the substrate (edge effect). In FIG. 8 , a dashed line is used to represent the material removal rate contour line corresponding to the polishing apparatus of the present invention. Since the carrier head 300 shown in FIG. 1 is configured, the carrier head 300 is configured with the flexible film 14 of the present invention, and the flexible film The included angle θ between the first bending portion 143a and the horizontal plane corresponding to the bending portion 143 of The control ability is effectively improved, the removal rate of the middle part and the edge part of the substrate is greatly balanced, and the global flattening of the substrate is realized.

The accompanying drawings in the present specification are schematic diagrams to assist in explaining the concept of the present invention, and schematically show the shapes of various parts and their mutual relationships. It should be understood that, in order to clearly represent the structure of each component of the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to denote the same parts in the drawings. In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, material, or characteristic described by an example or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms 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.

Although 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 in these embodiments without departing from the principles and spirit of the invention, The scope of the invention is defined by the claims and their equivalents.

Claims

A flexible film for chemical mechanical polishing, characterized in that it comprises:

a circular bottom portion for receiving the substrate;

An annular edge side wall, the edge side wall has an upright portion extending vertically upward along the periphery of the bottom plate portion, a bent portion disposed on the upper side of the upright portion, and extending from the upper end of the bent portion to the upright portion. the inner side of the bottom plate part is horizontally extended to form a first horizontal extension part, and the bottom of the edge side wall is integrally formed with the bottom plate part;

and an annular vertical inner side wall arranged concentrically adjacent to the edge side wall, the inner side wall has at its top end a second horizontal extension portion bent horizontally to the inner side of the bottom plate portion, the inner side wall the wall is integral with the floor portion at its bottom;

The bent portion includes a first bent portion that is bent upward and inward from the upright portion and a second bent portion that is bent upward and outward from the first bent portion. The included angle between the folded portion and the horizontal plane is not equal to the included angle between the second folded portion and the horizontal plane.
The flexible film according to claim 1, wherein the included angle between the first bending portion and the horizontal plane is smaller than the included angle between the second bending portion and the horizontal plane.
The flexible film according to claim 2, wherein the angle between the first bending portion and the horizontal plane is 1-10° smaller than the angle between the second bending portion and the horizontal plane.
2. The flexible film of claim 1, wherein the bent portion extends outwardly no more than a circumferential outer surface of the upright portion.
The flexible film according to claim 1, wherein the angle between the first bending portion and the horizontal plane is 1-25°.
The flexible film according to claim 1, wherein a horizontal projection of the inwardly bent portion of the bent portion does not exceed the inner edge of the first horizontal extension portion.
The flexible film of claim 1, further comprising a spacer plate extending radially inwardly from the inner surface of the edge side wall, the inner edge of the spacer plate being wider than the second horizontally extending portion. The inner edge is away from the center of the bottom plate portion.
The flexible film according to claim 7, wherein the horizontal distance between the inner edge of the spacer plate and the inner edge of the second horizontally extending portion is 2-10 mm.
A carrier head for chemical mechanical polishing, characterized by comprising the flexible film for chemical mechanical polishing according to any one of claims 1 to 8.
A polishing apparatus, characterized by comprising the carrying head for chemical mechanical polishing as claimed in claim 9 .