A carrier head for chemical mechanical polishing

Abstract

The utility model relates to chemical mechanical polishing technical field provides a kind of for chemical mechanical polishing's bearing head, comprising: positioning member, support plate, first flexible film, first pipeline and drive structure, positioning member is equipped with first recess;Support plate is set in first recess, the side of support plate away from positioning member is equipped with second recess;First flexible film is covered in support plate outside, and first gas chamber is formed between first flexible film and second recess;First pipeline is communicated with first gas chamber;The both ends of drive structure are respectively connected with the groove bottom of first recess and support plate;In the case where first gas chamber is under negative pressure, drive structure drives support plate to move upwards, and first flexible film adsorbs wafer;In the case where first gas chamber is under positive pressure, drive structure drives support plate to move downwards, and first flexible film presses wafer.Upon the bearing head for chemical mechanical polishing described above, it is not necessary to adhere adsorption pad on first flexible film, avoid the processing quality of wafer being influenced by adsorption pad drop.

Description

Technical Field

[0001] This utility model relates to the field of chemical mechanical polishing technology, and in particular to a support head for chemical mechanical polishing. Background Technology

[0002] Chemical mechanical polishing (CMP), a key ultra-precision surface finishing technology for global planarization, has wide applications in semiconductor manufacturing and other fields. Its core principle is as follows: the wafer to be processed is placed under a support head, so that the bottom surface of the wafer contacts a rotating polishing pad; driven by a drive mechanism, the support head and polishing pad rotate in the same direction, applying a downward load to the wafer through the support head; simultaneously, polishing fluid is delivered to the contact area between the polishing pad and the wafer, and through the synergistic effect of chemical etching and mechanical abrasion, material removal is achieved from the wafer surface, ultimately achieving the goal of global planarization.

[0003] Currently, existing technologies typically employ an airbag-surfaced adsorption pad structure to achieve pressure control and positioning of the wafer. Specifically, a resin hard ring, slightly thinner than the wafer, is adhered to the outer ring of the adsorption pad. The adsorption pad primarily applies controllable pressure to the wafer, while the resin hard ring positions the wafer to ensure stability during processing. However, this structure has significant drawbacks in practical applications: firstly, the adsorption pad is constantly exposed to the polishing fluid environment, making it susceptible to corrosion; secondly, the relative movement between the polishing pad and the adsorption pad during polishing generates continuous mechanical friction, leading to rapid wear and tear on the adsorption pad and a generally short lifespan. More seriously, when the adsorption pad detaches during polishing, the fragments may mix into the polishing fluid, causing scratches or other damage to the wafer surface, severely impacting product quality and resulting in significant economic losses. Utility Model Content

[0004] The purpose of this invention is to provide a carrier head for chemical mechanical polishing, which aims to solve the problem that the existing carrier head affects the quality of the wafer due to the detachment of the adsorption pad.

[0005] To solve the above-mentioned technical problems, the present invention provides a support head for chemical mechanical polishing, comprising: A positioning component, one side of which is used to connect to an external driving mechanism, and the other side of which is provided with a first groove for positioning the wafer; A support plate is disposed in the first groove, and a second groove is provided on the side of the support plate opposite to the positioning member; A first flexible membrane covers the outside of the support plate, and a first air chamber is formed between the first flexible membrane and the second groove; A first pipeline passes through the positioning member and the support plate and is connected to the first air chamber. The first pipeline is used to connect to an external air source. A driving structure, wherein both ends of the driving structure are respectively connected to the bottom of the first groove and the support plate, and the driving structure is used to drive the support plate to move along a first direction; When the first air chamber is under negative pressure, the driving structure drives the support plate to move along the first direction, and the first flexible membrane adsorbs the wafer; when the first air chamber is under positive pressure, the first flexible membrane expands to press against the wafer.

[0006] Preferably, the second groove is an arc-shaped groove.

[0007] Preferably, there are multiple second grooves, and any one of the second grooves is connected to the first pipeline; Multiple first air chambers are formed between the multiple second grooves and the first flexible membrane, and the multiple first air chambers are connected when the first air chambers are under positive pressure.

[0008] Preferably, the driving structure includes: The second flexible membrane has a ring structure, and its two ends are respectively connected to the bottom of the first groove and the support plate. A second air chamber is formed inside the second flexible membrane. The second pipeline passes through the positioning member and communicates with the second air chamber. The second pipeline is used to connect to an external air source. Specifically, when the second air chamber is under negative pressure, the second flexible membrane drives the support plate to move upward; when the second air chamber is under positive pressure, the second flexible membrane squeezes the edge of the support plate.

[0009] Preferably, the driving structure further includes: A first clamping ring is disposed on the surface of the support plate facing the bottom of the first groove, and the first end of the second flexible membrane is fixed between the first clamping ring and the support plate; The second clamping ring is disposed at the bottom of the first groove, and the second end of the second flexible membrane is fixed between the second clamping ring and the positioning member.

[0010] Preferably, the second flexible membrane has annular protrusions at both ends, and the first clamping ring and the second clamping ring fix the two ends of the second flexible membrane through the annular protrusions.

[0011] Preferably, the surface of the first clamping ring facing the support plate is provided with a first annular groove, the surface of the second clamping ring facing the bottom of the groove is provided with a second annular groove, and a pair of annular protrusions are respectively embedded in the first annular groove and the second annular groove.

[0012] Preferably, the support plate has a third annular groove on its surface facing the first clamping ring, and a fourth annular groove is provided at the bottom of the groove. A pair of annular protrusions are respectively embedded in the third annular groove and the fourth annular groove.

[0013] Preferably, the positioning element includes: A connecting plate, through which the first pipe and the second pipe pass, the connecting plate being used to connect with an external drive mechanism; A positioning ring is disposed on one side of the connecting plate, and the interior of the positioning ring is configured to form the first groove.

[0014] Preferably, the bearing head for chemical mechanical polishing further includes a connecting shaft connected to the connecting plate, with the first and second conduits passing through the connecting shaft, which is used to connect to an external drive mechanism. To achieve the above objectives, this utility model also provides a polishing machine including the aforementioned polishing head.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The carrier head for chemical mechanical polishing provided by this utility model has a first groove on the positioning component. The groove wall of the first groove plays a positioning role for the wafer, eliminating the need to stick an adsorption pad on the first flexible film. This avoids the adsorption pad falling off and affecting the wafer processing quality, thus improving the wafer quality and yield. At the same time, the carrier head has a simple structure, low manufacturing cost, and longer service life. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a schematic diagram of the structure of the support head for chemical mechanical polishing provided in an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 The enlarged view of point A shown in the image.

[0019] Explanation of reference numerals in the accompanying drawings of this utility model: Positioning component 10, connecting plate 11, positioning ring 12, support plate 20, second groove 21, first air chamber 22, membrane 30, first pipeline 40, flexible membrane 51, second pipeline 52, first pressing ring 53, second pressing ring 54, second air chamber 55, connecting shaft 60, wafer 100, first groove 101, annular protrusion 511, first annular groove 531, second annular groove 541.

[0020] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0024] like Figure 1As shown in the embodiment of this utility model, the support head for chemical mechanical polishing includes: a positioning element 10, a support plate 20, a first flexible membrane 30, a first conduit 40, and a driving structure. One side of the positioning element 10 is used to connect to an external driving mechanism, and the other side of the positioning element 10 is provided with a first groove 101, which is used to position the wafer 100. The support plate 20 is disposed in the first groove 101, and the side of the support plate 20 opposite to the positioning element 10 is provided with a second groove 21. The first flexible membrane 30 covers the support plate 20, and a first air chamber 22 is formed between the first flexible membrane 30 and the second groove 21. The first conduit 40 passes through the positioning element 10 and the support plate 20 and communicates with the first air chamber 22. The first conduit 40 is used to connect to an external air source. The two ends of the driving structure are respectively connected to the bottom of the first groove 101 and the support plate 20, and the driving structure is used to drive the support plate 20 to move along a first direction.

[0025] Specifically, in this embodiment, a first groove 101 is provided on one side of the positioning member 10. The shape of the first groove 101 matches the shape of the support plate 20. Taking the support plate 20 as a circular plate, the first groove 101 is a circular groove. The first flexible film 30 is connected to the circumferential surface of the support plate 20 so that the first flexible film 30 and the support plate 20 form a gas film structure, and the wafer 100 is located below the first flexible film 30. In this embodiment, the first flexible film 30 can be bonded to the circumferential surface of the support plate 20, or it can be connected in other ways, such as: the circumferential surface of the support plate 20 is provided with an annular groove, the edge of the first flexible film 30 is provided with an annular protrusion, the annular protrusion is embedded in the annular groove, and then a connecting ring is fitted over the first flexible film 30 and connected to the circumferential surface of the support plate 20 so that the first flexible film 30 is firmly connected to the support plate 20 and prevents the first flexible film 30 from separating from the support plate 20 when it expands.

[0026] The support plate 20 has a second groove 21 on its surface facing the first flexible membrane 30, forming a first air chamber 22 between the second groove 21 and the first flexible membrane 30. The first air chamber 22 has three states: negative pressure, positive pressure, and exhaust. When the first air chamber 22 is evacuated through the first pipe 40, it is in a negative pressure state, the first flexible membrane 30 contracts, a pressure difference exists on both sides of the wafer 100, and the wafer 100 is adsorbed by the air film structure. When positive pressure air is introduced into the first air chamber 22 through the first pipe 40, it is in a positive pressure state, the first flexible membrane 30 expands, and presses against the wafer 100 to apply pressure to the wafer 100. In addition, the air in the first air chamber 22 can also be discharged through the first pipe 40. The wafer 100 is located below the first flexible film 30 and within the first groove 101. When the wafer 100 is polished, the positioning element 10 abuts against the polishing pad, and the groove wall of the first groove 101 positions the wafer 100, ensuring that no wafer fly occurs during the polishing process.

[0027] An external drive mechanism is used to move or rotate the positioning component 10 up and down, thereby moving or rotating the entire support head up and down. During wafer 100 processing, the external drive mechanism moves the entire support head to the wafer 100, and then moves the support head downwards, aligning the first flexible film 30 with the wafer 100. The first air chamber 22 is evacuated, and the drive structure moves the support plate 20 upwards. The air film structure then adsorbs the wafer 100, lifting the support head. When the support head transfers the wafer 100 to the polishing pad, it descends, introducing positive pressure air into the first air chamber 22. The first flexible film 30 expands, pressing against the wafer 100 to apply pressure to the back side of the wafer 100.

[0028] In the embodiments of this utility model, the positioning member 10 can be an integral structure or a split structure; when the positioning member 10 is an integral structure, a first groove 101 is provided on one side; when the positioning member 10 is a split structure, it can be formed by connecting a circular plate and a circular ring, and the first groove 101 is formed inside the circular ring.

[0029] In embodiments of this utility model, the driving structure can be a telescopic actuator, such as a hydraulic cylinder. The cylinder body is connected to the bottom of the first groove 101 of the positioning member 10, and the hydraulic rod of the hydraulic cylinder is connected to the support plate 20. When the hydraulic rod retracts, it can drive the support plate 20 to move along the first direction, thereby driving the air film structure to move along the first direction. Optionally, this type of actuator can also be a pneumatic cylinder or an electric cylinder.

[0030] Optionally, the driving structure can also be a gas chamber structure made of a flexible membrane. The flexible membrane is annular, with its two ends connected to the support plate 20 and the bottom of the first groove 101, respectively. The interior of the flexible membrane is connected to a pipeline. By evacuating the interior of the flexible membrane, the flexible membrane can drive the support plate 20 to move along a first direction when it contracts. In this embodiment of the present invention, the first direction is upward.

[0031] The carrier head for chemical mechanical polishing provided in this embodiment of the invention, by setting a first groove on the positioning component, the groove wall of the first groove plays a positioning role for the wafer, eliminating the need to adhere an adsorption pad to the first flexible film, avoiding the adsorption pad falling off and affecting the wafer processing quality, and improving the wafer quality and yield; at the same time, the carrier head has a simple structure, low manufacturing cost, and longer service life.

[0032] Optionally, the second groove 21 can be a rectangular groove or an arc-shaped groove. In this embodiment, the second groove 21 is an arc-shaped groove, which forms an arc-shaped gas chamber with the first flexible membrane 30. The arc-shaped groove is more conducive to vacuuming, so as to use negative pressure to adsorb the wafer 100.

[0033] Optionally, the number of arc-shaped grooves can be one or more. When there are multiple arc-shaped grooves, any one of them is connected to the first conduit 40. Multiple arc-shaped grooves and the first flexible membrane 30 form multiple first air chambers 22. When the first air chambers 22 are under positive pressure, the multiple first air chambers 22 are connected, and the first flexible membrane 30 can uniformly press against the wafer 100 when it expands. In this embodiment, a proportional valve can be provided on the first conduit 40. The proportional valve can precisely control the air pressure in the first air chambers 22. Combined with the flexibility of the first flexible membrane 30, the pressure direction can be ensured to be along the normal direction of the wafer 100, thereby precisely controlling the pressure applied by the first flexible membrane 30 to the surface of the wafer 100.

[0034] like Figure 2 As shown, in an embodiment of this utility model, the driving structure includes a second flexible membrane 51 and a second conduit 52. The second flexible membrane 51 has an annular structure, and its two ends are respectively connected to the bottom of the first groove 101 and the support plate 20. A second air chamber 55 is formed inside the second flexible membrane 51. The second conduit 52 passes through the positioning member 10 and communicates with the second air chamber 55. The second conduit 52 is used to connect to an external air source.

[0035] Specifically, in this embodiment, the two ends of the second flexible membrane 51 can be fixed to the support plate 20 and the bottom of the first groove 101 respectively by adhesive bonding, so that a closed space is formed inside the second flexible membrane 51, which is the second air chamber 55. The second pipe 52 is connected to the second air chamber 55, and the second air chamber 55 also has a negative pressure state, a positive pressure state, and an exhaust state. When the second air chamber 55 is evacuated through the second pipe 52, the second flexible membrane 51 contracts, causing the support plate 20 to move upward; when positive pressure air is injected into the second air chamber 55 through the second pipe 52, the second flexible membrane 51 expands, squeezing the edge of the support plate 20 to apply pressure to the edge of the wafer 100. At the same time, the gas in the second air chamber 55 can also be discharged through the second pipe 52.

[0036] In this embodiment, when the wafer 100 needs to be adsorbed, both the first air chamber 22 and the second air chamber 55 are under negative pressure. The second flexible membrane 51 uses the negative pressure to drive the air film structure upward, and the air film structure uses the negative pressure to adsorb the wafer 100. When the wafer 100 needs to be polished, both the first air chamber 22 and the second air chamber 55 are under positive pressure. The first flexible membrane 30 expands and presses against the wafer 100, and the second flexible membrane 51 expands and squeezes the edge of the support plate 20 to apply pressure to the edge of the wafer 100.

[0037] Furthermore, a proportional valve can also be installed on the second pipeline 52 to precisely control the air pressure in the second air chamber 55. Combined with the flexibility of the second flexible membrane 51, this ensures that the pressure direction is along the normal direction of the wafer 100, thereby precisely controlling the pressure applied to the edge of the wafer 100 by the air film structure. In this embodiment, when the first flexible membrane 30 expands, it can apply force uniformly to the center of the wafer 100, and when the second flexible membrane 51 expands, it can apply force uniformly to the edge of the wafer 100, ensuring that the surface of the wafer 100 is uniformly stressed during polishing, thus improving processing accuracy.

[0038] like Figure 2 As shown, in an embodiment of this utility model, the driving structure further includes: a first clamping ring 53 and a second clamping ring 54. The first clamping ring 53 is disposed on the surface of the support plate 20 facing the bottom of the first groove 101, and the first end of the second flexible membrane 51 is fixed between the first clamping ring 53 and the support plate 20. The second clamping ring 54 is disposed at the bottom of the first groove 101, and the second end of the second flexible membrane 51 is fixed between the second clamping ring 54 and the positioning member 10.

[0039] Specifically, in this embodiment, the two ends of the second flexible membrane 51 can be bonded to the support plate 20 and the bottom of the first groove 101, respectively. Then, the first pressing ring 53 is connected to the support plate 20 to press the first end of the second flexible membrane 51. Similarly, the second pressing ring 54 is connected to the bottom of the first groove 101 to press the second end of the second flexible membrane 51 to prevent the second flexible membrane 51 from separating from the support plate 20 or the positioning member 10 when it expands.

[0040] like Figure 2 As shown, in an embodiment of this utility model, the two ends of the second flexible membrane 51 are provided with annular protrusions 511, and the first pressing ring 53 and the second pressing ring 54 fix the two ends of the second flexible membrane 51 through the annular protrusions 511.

[0041] Specifically, in an optional embodiment, the surface of the first clamping ring 53 facing the support plate 20 is provided with a first annular groove 531, and the surface of the second clamping ring 54 facing the bottom of the first groove 101 is provided with a second annular groove 541. A pair of annular protrusions 511 are respectively embedded in the first annular groove 531 and the second annular groove 541 to press the two ends of the second flexible membrane 51 together. In this embodiment, the pair of annular protrusions may be located on the outside of the second flexible membrane 51, or the annular protrusion embedded in the first annular groove 531 may be located on the outside of the second flexible membrane 51, while the annular protrusion embedded in the second annular groove 541 may be located on the inside of the second flexible membrane 51.

[0042] In another optional embodiment, the support plate 20 has a third annular groove on its surface facing the first clamping ring 53, and a fourth annular groove is provided at the bottom of the first groove 101. A pair of annular protrusions are respectively embedded in the third annular groove and the fourth annular groove. In this embodiment, the annular protrusion embedded in the third annular groove is located inside the second flexible membrane 51, and the annular protrusion embedded in the fourth annular groove is located outside the second flexible membrane 51.

[0043] It should be noted that in the above-described embodiments, the wall of the second flexible membrane 51 surrounding the second air chamber 55 is the inner side, and the other side is the outer side.

[0044] like Figure 1 As shown, in this embodiment of the present invention, the positioning member 10 is a split structure, consisting of a connecting plate 11 and a positioning ring 12. The positioning ring 12 is disposed on one side of the connecting plate 11, and the hollow structure of the positioning ring 12 forms a first groove 101. The first pipe 40 and the second pipe 52 pass through the connecting plate 11 to connect to an external air source. During the polishing of the wafer 100, the end of the positioning ring 12 facing away from the connecting plate 11 abuts against the polishing pad, and the wafer 100 is located inside the positioning ring 12 to position the wafer 100. In this embodiment, an external driving mechanism can be connected to the connecting plate 11 to drive the connecting plate 11 to move up and down, rotate, or move.

[0045] like Figure 1 As shown in the embodiment of this utility model, the bearing head for chemical mechanical polishing further includes a connecting shaft 60, which is connected to the connecting plate 11. The first pipe 40 and the second pipe 52 pass through the connecting shaft 60. The connecting shaft 60 is used to connect to an external drive mechanism to drive the bearing head to move.

[0046] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A support head for chemical mechanical polishing, characterized in that, include: A positioning component, one side of which is used to connect to an external driving mechanism, and the other side of which is provided with a first groove for positioning the wafer; A support plate is disposed in the first groove, and a second groove is provided on the side of the support plate opposite to the positioning member; A first flexible membrane covers the outside of the support plate, and a first air chamber is formed between the first flexible membrane and the second groove; A first pipeline passes through the positioning member and the support plate and is connected to the first air chamber. The first pipeline is used to connect to an external air source. A driving structure, wherein both ends of the driving structure are respectively connected to the bottom of the first groove and the support plate, and the driving structure is used to drive the support plate to move along a first direction; When the first air chamber is under negative pressure, the driving structure drives the support plate to move along the first direction, and the first flexible membrane adsorbs the wafer; when the first air chamber is under positive pressure, the first flexible membrane expands to press against the wafer.

2. The carrier head for chemical mechanical polishing according to claim 1, characterized by The second groove is an arc-shaped groove.

3. The carrier head for chemical mechanical polishing according to claim 2, wherein There are multiple second grooves, and any one of the second grooves is connected to the first pipeline; Multiple first air chambers are formed between the multiple second grooves and the first flexible membrane, and the multiple first air chambers are connected when the first air chambers are under positive pressure.

4. The carrier head for chemical mechanical polishing according to claim 1, wherein The driving structure includes: The second flexible membrane has a ring structure, and its two ends are respectively connected to the bottom of the first groove and the support plate. A second air chamber is formed inside the second flexible membrane. The second pipeline passes through the positioning member and communicates with the second air chamber. The second pipeline is used to connect to an external air source. Specifically, when the second air chamber is under negative pressure, the second flexible membrane drives the support plate to move upward; when the second air chamber is under positive pressure, the second flexible membrane squeezes the edge of the support plate.

5. The carrier head for chemical mechanical polishing according to claim 4, wherein The driving structure also includes: A first clamping ring is disposed on the surface of the support plate facing the bottom of the first groove, and the first end of the second flexible membrane is fixed between the first clamping ring and the support plate; The second clamping ring is disposed at the bottom of the first groove, and the second end of the second flexible membrane is fixed between the second clamping ring and the positioning member.

6. The carrier head for chemical mechanical polishing according to claim 5, wherein The second flexible membrane has annular protrusions at both ends, and the first and second clamping rings fix the two ends of the second flexible membrane through the annular protrusions.

7. The carrier head for chemical mechanical polishing according to claim 6, wherein The first clamping ring has a first annular groove on its surface facing the support plate, and the second clamping ring has a second annular groove on its surface facing the bottom of the groove. A pair of annular protrusions are respectively embedded in the first annular groove and the second annular groove.

8. The carrier head for chemical mechanical polishing according to claim 6, wherein The support plate has a third annular groove on its surface facing the first clamping ring, and a fourth annular groove is provided at the bottom of the groove. A pair of annular protrusions are respectively embedded in the third annular groove and the fourth annular groove.

9. The carrier head for chemical mechanical polishing according to claim 4, wherein The positioning element includes: A connecting plate, through which the first pipe and the second pipe pass, the connecting plate being used to connect with an external drive mechanism; A positioning ring is arranged on one side of the connecting plate, and an inner part of the positioning ring is configured as the first groove.

10. The carrier head for chemical mechanical polishing according to claim 9, wherein Further comprising a connecting shaft connected with the connecting plate, the first pipeline and the second pipeline are arranged through the connecting shaft, and the connecting shaft is used for being connected with an external driving mechanism.

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