A polishing head liquid supply unit

Abstract

The utility model discloses a kind of liquid supply units of polishing head, comprising: polishing head, at least including pedestal, rotating shaft for driving pedestal rotation, and flexible film covered in pedestal;Liquid supply source is used to provide fluid, with liquid outlet;The flexible film includes first film part located at the bottom of pedestal, can be contacted with wafer, and second film part located at the periphery of first film part, the second film part covers the side and part top of pedestal;The polishing head has flow guide channel, the end of this flow guide channel has the liquid supply port of setting towards second film part, the liquid outlet is communicated with flow guide channel, to send fluid to liquid supply port.This utility model pertinently proposes the cleaning problem of flexible film second film part, effectively prevent the second film part material solidification problem of flexible film, improve the service life of flexible film, and reduce the defect of flexible film.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor integrated circuit chip manufacturing technology, and in particular relates to a polishing head liquid supply unit. Background Technology

[0002] Existing polishing heads can only clean the lower surface of the flexible membrane. Due to the presence of the retaining ring, polishing fluid tends to accumulate on the sides of the flexible membrane, and this area is difficult to clean, resulting in polishing fluid residue. Furthermore, disassembling the flexible membrane for cleaning takes too long, affecting the final polishing efficiency.

[0003] In addition, when the polishing head is not in use, the flexible membrane needs to be kept moist. Typically, the flexible membrane is made of silicone. When the flexible membrane undergoes multiple cycles of moisture and dryness, its properties, such as elasticity, are easily altered, ultimately negatively impacting the polishing process. Therefore, it is necessary to supply liquid to the flexible membrane when the polishing head is not in use to maintain its moisture level.

[0004] Furthermore, in the existing technology, the polishing slurry is replenished during polishing by retaining rings or grooves on the surface of the polishing pad. In the actual process, the amount of polishing slurry required at different diameters of the polishing pad will also be different, and there is no control over the distribution of polishing slurry in the polishing area. Therefore, the controllability of polishing slurry replenishment is not high. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, this utility model provides a polishing head liquid supply unit, which solves the problem of incomplete cleaning of flexible membranes and improves the controllability of polishing liquid distribution.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a polishing head liquid supply unit, comprising:

[0007] A polishing head includes at least a base, a rotating shaft for driving the base to rotate, and a flexible membrane covering the base;

[0008] A liquid supply source, used to provide fluid, has a liquid outlet;

[0009] The flexible film includes a first film portion located at the bottom of the base and in contact with the wafer, and a second film portion located on the outer periphery of the first film portion, the second film portion covering the side and part of the top of the base;

[0010] The polishing head has a flow channel, the end of which has a liquid supply port facing the second membrane portion, and the liquid outlet is connected to the flow channel to deliver fluid to the liquid supply port.

[0011] Furthermore, the second membrane portion includes a membrane portion one covering the side portion of the base and a membrane portion two covering the outer ring of the top of the base. The liquid supply port faces the membrane portion one, or the liquid supply port faces the membrane portion two, or the liquid supply port faces both the membrane portion one and the membrane portion two.

[0012] Furthermore, the flow channel includes a main flow channel extending circumferentially along the base, and multiple branch flow channels connected to the main flow channel, with the end of each branch flow channel forming a liquid supply port.

[0013] Furthermore, the branch flow channel extends along the height direction of the polishing head, and its opening cross-section is a long groove shape. Multiple branch flow channels are evenly distributed around the polishing head, and the liquid supply port faces the membrane body.

[0014] or,

[0015] The branch channel extends along the height direction of the polishing head, and its longitudinal section is conical. Its inner radial direction gradually increases towards the main channel, and the liquid supply port faces the membrane body.

[0016] or,

[0017] The longitudinal section of the branch channel is L-shaped, and the liquid supply port faces the membrane body.

[0018] or,

[0019] The longitudinal section of the branch channel is V-shaped with the opening facing the second membrane section, and the liquid supply port faces the membrane section body.

[0020] Furthermore, the main channel is formed by sealing and splicing the first polishing head housing and the second polishing head housing together, and both the inner and outer rings of the main channel have sealing elements.

[0021] Furthermore, the polishing head includes a first polishing head housing, a second polishing head housing located below the first polishing head housing, and a retaining ring located below the second polishing head housing. The flow guiding channel is disposed in the retaining ring, and the starting end of the flow guiding channel is located on the outer wall of the retaining ring; or, the flow guiding channel extends within the first polishing head housing and the second polishing head housing; or, the flow guiding channel extends within the first polishing head housing, the second polishing head housing, and the retaining ring.

[0022] Furthermore, the flow channel has an inclined flow surface that extends inclinedly from the outside to the inside and from top to bottom to increase the liquid supply port, which faces the membrane body one and the membrane body two.

[0023] Furthermore, the fluid is a cleaning liquid, or the fluid is a polishing liquid.

[0024] Furthermore, the polishing head and the liquid supply source rotate relative to each other.

[0025] Furthermore, the liquid supply source is an external water source, or the liquid supply source is a water source in the internal processing channel of the polishing head.

[0026] The beneficial effects of this utility model are: 1) It specifically addresses the cleaning problem of the second membrane portion of the flexible membrane, effectively preventing the solidification of the material in the second membrane portion, improving the service life of the flexible membrane, and reducing defects in the flexible membrane; 2) When the polishing head is not in working condition, the second membrane portion of the flexible membrane can be rinsed and moistened using the liquid supply source to ensure that the flexible membrane is in a wetted state, extending its service life and ensuring its performance; 3) The flow channel has various opening forms to adapt to different application scenarios and has high flexibility of use; 4) The branch flow channel design allows for cleaning of the flexible membrane in all directions, without being limited by location. Attached Figure Description

[0027] Figure 1 Partial cross-sectional view of this utility model Figure 1 .

[0028] Figure 2 This is a simplified cross-sectional view of the flexible membrane and the base in this utility model.

[0029] Figure 3 This is a top view of the present invention.

[0030] Figure 4 Partial cross-sectional view of this utility model Figure 2 .

[0031] Figure 5 This is an internal top view of the present invention.

[0032] Figure 6 Partial cross-sectional view of this utility model Figure 3 .

[0033] Figure 7 This is the front view of the present invention.

[0034] Figure 8 Partial cross-sectional view of this utility model Figure 4 .

[0035] Among them, 1-polishing head, 11-flow guide channel, 111-liquid supply port, 112-main flow channel, 113-branch flow channel, 114-flow guide surface, 12-first polishing head housing, 13-second polishing head housing, 14-retaining ring, 2-base, 21-base side, 22-base top, 3-rotating shaft, 4-flexible membrane, 41-first membrane part, 42-second membrane part, 421-membrane part body one, 422-membrane part body two, 5-liquid supply source, 51-liquid outlet, 6-sealant. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0037] A polishing head fluid supply unit includes a polishing head 1 and a fluid supply source 5 for providing fluid. The polishing head 1 includes at least a base 2, a rotating shaft 3 for driving the base 2 to rotate, and a flexible membrane 4 covering the lower part of the base 2.

[0038] like Figure 2 As shown, the flexible film 4 includes a first film portion 41 located at the bottom of the base 2 and capable of contacting the wafer, and a second film portion 42 located on the outer periphery of the first film portion 41. The second film portion 42 covers the side portion 21 and part of the top 22 of the base 2. In other words, the flexible film 4 covers the bottom surface, side surface, and top surface of the base 2. Specifically, the first film portion 41 covers the bottom surface of the base 2, and the second film portion 42 covers the side surface and top surface of the base 2, that is, the second film portion 42 covers the side portion 21 and part of the top 22 of the base 2.

[0039] The structure of the flexible membrane 4 and the base 2, and their assembly and connection structure, can be achieved by existing technology and will not be described in detail here.

[0040] The polishing head 1 has a flow channel 11, the end of which has a liquid supply port 111 facing the second membrane 42. The liquid outlet 51 is connected to the flow channel 11, thereby conveying fluid to the liquid supply port 111 and conveying the fluid to the position of the second membrane 42.

[0041] During the process, the liquid supply source 5 delivers fluid to the guide channel 11 through the liquid outlet 51. The fluid in the guide channel 11 is then delivered to the second membrane section 42 of the flexible membrane 4 through the liquid supply port 111. This fluid can be a cleaning fluid, specifically deionized water; or it can be a polishing liquid, with no specific limitation. The exact location of the fluid delivery to the second membrane section 42 is not specified here.

[0042] In detail, the second membrane portion 42 includes a membrane portion body 421 covering the side portion 21 of the base 2, and a membrane portion body 422 covering the outer ring of the top portion 22 of the base 2. The liquid supply port 111 may face only the membrane portion body 421, or the liquid supply port 111 may face only the membrane portion body 422, or the liquid supply port 111 may face both the membrane portion body 421 and the membrane portion body 422.

[0043] like Figure 1, Figure 3 As shown, the liquid supply source 5 is an external water source, which is located above the polishing head 1. The fluid is a cleaning solution. The guide channel 11 includes a main channel 112 extending circumferentially along the base 2, i.e., along the polishing head 1, and multiple branch channels 113 connected to the main channel 112. The end of each branch channel 113 forms a liquid supply port 111. In this embodiment, the main channel 112 is formed by a recess from the upper surface of the polishing head 1, and it is an open annular shape. The cross-section of the branch channels 113 is circular or racetrack-shaped, and the starting end of each branch channel 113 is located on the inner bottom surface of the main channel 112.

[0044] Branch channels 113 extend along the height of the polishing head 1, and their opening cross-section is a long groove. Multiple branch channels 113 are evenly distributed around the polishing head 1. The liquid supply port 111 faces the membrane body 422. The liquid outlet 51 is located above the polishing head 1. The cleaning liquid is output from the top of the polishing head 1 from top to bottom. It first enters the main channel 112, and then guides and cleans the membrane body 422 of the flexible membrane 4 through multiple branch channels 113. Of course, the fluid will also flow from top to bottom to the membrane body 421, that is, both the membrane body 421 and the membrane body 422 are guided and cleaned.

[0045] During the cleaning process, the polishing head 1 and the liquid supply source 5 rotate relative to each other. This includes situations where the polishing head 1 remains stationary while the liquid supply source 5 rotates, where the polishing head 1 rotates while the liquid supply source 5 remains stationary, and where both the polishing head 1 and the liquid supply source 5 rotate simultaneously. Because the branch channels 113 are evenly spaced around the circumference of the polishing heads 1, and their opening cross-section is a long groove shape, it is beneficial to increase the time for the cleaning fluid to rinse the second membrane portion 42 of the flexible membrane 4, and to ensure the connection strength of the base 2 of the polishing head 1.

[0046] like Figure 4 As shown, in this embodiment, the branch channel 113 extends along the height direction of the polishing head 1, and its longitudinal section is tapered. Its inner radial direction gradually increases towards the main channel 112. In other words, with... Figure 4 Taking the direction shown as an example, the longitudinal section of the branch channel 113 is larger at the top and smaller at the bottom, and the liquid supply port 111 also faces the membrane body 422.

[0047] Unlike the previous implementation, in this case, the liquid supply source 5 is the water source for the internal processing channel of the polishing head 1. That is, the liquid supply source 5 is built into the polishing head 1. The two ends of the water pipe are connected to the cleaning fluid inside the polishing head 1 and the upper surface of the polishing head 1, respectively, and an outlet 51 is formed at the end of the water pipe. The cleaning fluid inside the polishing head 1 is guided to the main channel 112 inside the polishing head 1 through the water pipe, and then guided and cleaned to the second membrane body 422 of the flexible membrane 4 through the branch channel 113. Of course, the fluid will also flow from top to bottom to the first membrane body 421, that is, both the first membrane body 421 and the second membrane body 422 are guided and cleaned.

[0048] At this time, the water pipe and polishing head 1 are relatively stationary, or the water pipe and polishing head 1 can rotate together. In order to ensure that the cleaning fluid in the main channel 112 can be delivered to the branch channel 113 more evenly, the cross-section of the branch channel 113 is designed as a micropore. The cleaning fluid first fills the main channel 112 as much as possible, and then is delivered to all parts of the flexible membrane 4 through the branch channel 113.

[0049] To ensure uniform rinsing of the flexible membrane in all directions, the main flow channel 112 is designed as a relatively sealed flow channel. Specifically, the polishing head 1 includes a first polishing head housing 12 and a second polishing head housing 13, which are sealed together to form the main flow channel 112. Figure 5 As shown, both the inner and outer rings of the main channel 112 have sealing elements 6 to ensure the relative sealing of the main channel 112, thereby allowing a slight pressure within the main channel 112, so that the liquid supply ports 111 of each branch channel 113 have water outlet pressure.

[0050] The polishing head 1 includes not only a first polishing head housing 12 and a second polishing head housing 13 located below the first polishing head housing 12, but also a retaining ring 14 located below the second polishing head housing 13. In the above embodiment, the flow channel 11 extends within the first polishing head housing 12 and the second polishing head housing 13, but does not extend to the retaining ring 14. Figure 6 , Figure 7 As shown, the flow channel 11 is only provided on the retaining ring 14, and the starting end of the flow channel 11 is located on the outer wall of the retaining ring 14, and the end of the flow channel 11 is located on the inner wall of the retaining ring 14. In other words, the flow channel 11 extends radially along the retaining ring 14. At this time, the liquid supply port 111 faces the second membrane 42, including facing only the first membrane body 421, and also facing both the first membrane body 421 and the second membrane body 422.

[0051] At this time, the external water source can remain relatively stationary. During the rotation of the polishing head 1 driven by the rotating shaft 3, the cleaning fluid is delivered to the circumference of the flexible membrane 4.

[0052] To increase the size of the liquid supply port 111, the flow channel 11 is designed with an inclined flow guiding surface 114. Figure 6 Taking the direction shown as an example, the guide surface 114 extends obliquely from the outside of the polishing head 1 inward and from top to bottom, that is, the cross-sectional area of ​​the starting end of the guide channel 11 is smaller than the cross-sectional area of ​​its end. In this embodiment, the guide channel 11 is completely opened in the retaining ring 14, and the upper part of the guide channel 11 is open, so that in the figure, the liquid supply port 111 faces the membrane body 421 and the membrane body 422.

[0053] like Figure 8As shown, the flow channel 11 extends within the first polishing head housing 12, the second polishing head housing 13, and the retaining ring 14. In this case, the liquid supply source 5 is the water source inside the polishing head 1. The main flow channel 112 of the flow channel 11 is located between the second polishing head housing 13 and the retaining ring 14. The longitudinal section of the branch flow channel 113 is L-shaped, and the liquid supply port 111 faces the membrane body 2 422. The cleaning fluid inside the polishing head 1 flows through a water pipe to the main flow channel 112 inside the polishing head 1, and then through the branch flow channel 113 to clean the membrane body 2 422 of the flexible membrane 4. The fluid also flows from top to bottom to the membrane body 1 421, thus cleaning both the membrane body 1 421 and the membrane body 2 422.

[0054] The above specific embodiments are used to explain and illustrate the present utility model, and are not intended to limit the present utility model. Any modifications and changes made to the present utility model within the spirit and scope of the claims shall fall within the protection scope of the present utility model.

Claims

1. A polishing head liquid supply unit, characterized in that, include: The polishing head (1) includes at least a base (2), a rotating shaft (3) for driving the base (2) to rotate, and a flexible membrane (4) covering the base (2). A liquid supply source (5) is used to supply fluid and has a liquid outlet (51). The flexible film (4) includes a first film portion (41) located at the bottom of the base (2) and in contact with the wafer, and a second film portion (42) located on the outer periphery of the first film portion (41), the second film portion (42) covering the side portion (21) and part of the top portion (22) of the base (2). The polishing head (1) has a flow channel (11) at the end of which is a liquid supply port (111) facing the second membrane portion (42). The liquid outlet (51) is connected to the flow channel (11) to deliver fluid to the liquid supply port (111).

2. The polishing head liquid supply unit according to claim 1, characterized in that: The second membrane portion (42) includes a membrane portion one (421) covering the side portion (21) of the base (2) and a membrane portion two (422) covering the outer ring of the top (22) of the base (2). The liquid supply port (111) faces the membrane portion one (421), or the liquid supply port (111) faces the membrane portion two (422), or the liquid supply port (111) faces both the membrane portion one (421) and the membrane portion two (422).

3. The polishing head liquid supply unit according to claim 1 or 2, characterized in that: The flow channel (11) includes a main flow channel (112) extending circumferentially along the base (2) and a plurality of branch flow channels (113) connected to the main flow channel (112), the end of which forms a liquid supply port (111).

4. The polishing head liquid supply unit according to claim 3, characterized in that: The branch flow channel (113) extends along the height direction of the polishing head (1), and its opening cross section is a long groove shape. Multiple branch flow channels (113) are evenly distributed around the polishing head (1). The liquid supply port (111) faces the membrane body (422). or, The branch channel (113) extends along the height direction of the polishing head (1), and its longitudinal section is conical. Its inner radial direction gradually increases towards the main channel (112), and the liquid supply port (111) faces the membrane body (422). or, The longitudinal section of the branch channel (113) is L-shaped, and the liquid supply port (111) faces the membrane body (422). or, The longitudinal section of the branch channel (113) is V-shaped with the opening facing the second membrane part (42), and the liquid supply port (111) faces the membrane part body (421).

5. The polishing head liquid supply unit according to claim 3, characterized in that: The main channel (112) is formed by sealing the first polishing head housing (12) and the second polishing head housing (13) together, and both the inner and outer rings of the main channel (112) have sealing elements (6).

6. The polishing head liquid supply unit according to claim 1 or 2, characterized in that: The polishing head (1) includes a first polishing head housing (12), a second polishing head housing (13) located below the first polishing head housing (12), and a retaining ring (14) located below the second polishing head housing (13). The flow channel (11) is disposed in the retaining ring (14), and the starting end of the flow channel (11) is located on the outer wall of the retaining ring (14); or, the flow channel (11) extends within the first polishing head housing (12) and the second polishing head housing (13); or, the flow channel (11) extends within the first polishing head housing (12), the second polishing head housing (13), and the retaining ring (14).

7. The polishing head liquid supply unit according to claim 6, characterized in that: The flow channel (11) has an inclined flow surface (114) that extends from the outside to the inside and from the top to the bottom to increase the liquid supply port (111), which faces the membrane body one (421) and the membrane body two (422).

8. The polishing head liquid supply unit according to claim 1, characterized in that: The fluid is a cleaning liquid, or the fluid is a polishing liquid.

9. The polishing head liquid supply unit according to claim 1, characterized in that: The polishing head (1) and the liquid supply source (5) rotate relative to each other.

10. The polishing head liquid supply unit according to claim 1, characterized in that: The liquid supply source (5) is an external water source, or the liquid supply source (5) is a water source in the internal processing channel of the polishing head (1).

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