Polishing head and chemical mechanical polishing apparatus

Abstract

The application provides a polishing head and a chemical mechanical polishing device. The polishing head comprises a polishing head body, an elastic air film, a first clamping device and a second clamping device. An installation space is formed at one end of the polishing head body in the axial direction. The elastic air film is arranged in the installation space, and the elastic air film forms a side film and a bottom film away from the bottom of the installation space. The first clamping device is in contact with the inner side surface of the side film, and the second clamping device is in contact with the outer side surface of the side film. The first clamping device and the second clamping device cooperate to clamp the side film. In the state of clamping the side film, the first clamping device and the second clamping device are annular structures. The circumferential dimensions of the annular structures of the first clamping device and the second clamping device can be adjusted to adjust the circumferential dimension of the elastic air film and change the edge stress of the polished wafer. The scheme can improve the compatibility of the polishing head.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical mechanical polishing, and in particular to a polishing head and a chemical mechanical polishing device. BACKGROUND

[0002] A chemical mechanical polishing device is a common device for chemical mechanical polishing of a wafer. A polishing head is an important component of chemical mechanical polishing. For example, in some chemical mechanical polishing devices, in addition to the polishing head, there is also a loading cup for carrying the wafer, and a polishing disc with a polishing pad. Some types of polishing heads include an air film, which can be used to adsorb the wafer from the loading cup, and to exert a suitable pressure on the wafer through the air film to press the wafer against the polishing disc with the polishing pad to achieve chemical mechanical polishing.

[0003] In this type of polishing head, in order to effectively transmit the pressure of the gas to the wafer to exert pressure on the wafer, the air film is generally made of elastic and relatively soft rubber. In order to prevent the side of the air film from tilting, a clamping device is needed to clamp the side of the air film to increase the rigidity of the side of the air film and ensure the stability of the edge of the air film.

[0004] The third generation semiconductor material can meet the new requirements of modern electronic technology for harsh conditions such as high temperature, high power, high voltage, high frequency and radiation resistance, etc. due to its wider band gap, higher thermal conductivity, higher breakdown field strength, higher saturated electron drift rate, higher bonding energy and other characteristics. The third generation semiconductor material has a wide range of applications in radio frequency communication, radar, satellite, power management, automotive electronics, industrial power electronics and other industries.

[0005] However, the third generation semiconductor material such as gallium nitride (GaN), silicon carbide (SiC), zinc oxide (ZnO) and diamond has the characteristics of extremely high hardness and difficult polishing. In some special requirements, the edge of the wafer needs to be thinned to be uneven with other areas to form a trim wafer (i.e. an edge-thinned wafer); when the conventional polishing head presses such a wafer against the polishing disc through the air film for chemical mechanical polishing, the polishing rate of the edge of the wafer is prone to increase sharply, resulting in poor chemical mechanical polishing effect, and this sharp increase is difficult to improve by adjusting the gas pressure transmitted by the air film.

[0006] Generally, for each size of trim wafer, a different size of air film is designed to adapt to it, and even different polishing heads need to be developed. Obviously, designing different sizes of air films and different polishing heads for each size of trim wafer will greatly complicate the management of the polishing head, increase the workload of the R&D personnel, and increase the difficulty of cost control. Therefore, a new technical solution is needed to at least partially improve such problems. SUMMARY

[0007] The present application provides a polishing head and a chemical mechanical polishing device to at least partially improve the above problems.

[0008] According to an aspect of the present application, a polishing head for a chemical mechanical polishing device is provided, comprising: a polishing head body, an elastic air film, a first clamping device and a second clamping device, one end of the polishing head body is formed with a mounting space, the elastic air film is arranged in the mounting space, and the elastic air film is formed with a side film and a bottom film away from the bottom of the mounting space; the first clamping device is in contact with the inner side surface of the side film, the second clamping device is in contact with the outer side surface of the side film, and the first clamping device and the second clamping device cooperate to clamp the side film; in the state of clamping the side film, the first clamping device and the second clamping device are both annular structures, and the circumferential dimensions of the annular structures of the first clamping device and the second clamping device can be adjusted to adjust the circumferential dimension of the elastic air film and change the edge stress of the polished wafer.

[0009] According to another aspect of the present application, a chemical mechanical polishing device is provided, comprising: a polishing unit, and the above-mentioned polishing head; the elastic air film of the polishing head is configured to adjust its circumferential dimension by the first clamping device and the second clamping device to change the edge stress of the polished wafer.

[0010] The polishing head in the present application has at least the following beneficial effects:

[0011] a. The first clamping device and the second clamping device can cooperate to clamp the side film, thereby improving the rigidity of the side film of the elastic air film and improving the stability of the edge of the elastic air film;

[0012] b. Since in the state of clamping the side film, the first clamping device and the second clamping device are both annular structures, and the circumferential dimensions of the annular structures of the first clamping device and the second clamping device can be adjusted, when different specifications of wafers need to be adsorbed, the circumferential dimensions of the annular structures of the first clamping device and the second clamping device can be adjusted as needed to adjust the clamping state of the side film of the elastic air film to a certain extent, thereby changing the edge stress of the polished wafer, so that the elastic air film can adapt to wafers of different specifications, solving the problem of sharp increase of polishing rate at the edge of the wafer, and improving the effect of chemical mechanical polishing;

[0013] c. Since the circumferential dimensions of the annular structures of the first and second clamping devices can be adjusted to accommodate trim wafers of different sizes, it is not necessary to design different elastic air films and polishing heads for trim wafers of different sizes. This improves the compatibility of the polishing heads, effectively reduces the complexity of polishing head management, reduces the workload of R&D personnel, and lowers the difficulty of cost control. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 A cross-sectional schematic diagram of some of the optional polishing heads in this application is shown.

[0016] Figure 2 It shows Figure 1 A schematic diagram at point Q1.

[0017] Figure 3 A schematic diagram of an optional first type structure in this application is shown.

[0018] Figure 4 It shows Figure 3 A schematic diagram at point Q2.

[0019] Figure 5 A schematic diagram of the overlapping portion of the arc-shaped plate in this application is shown.

[0020] Figure 6 A cross-sectional schematic diagram of some other optional polishing heads in this application is shown.

[0021] Figure 7 A schematic diagram of an optional second type of structure in this application is shown.

[0022] Figure 8 A schematic diagram of one of the optional links in this application is shown.

[0023] Figure 9A A top view schematic diagram of the connection state between two adjacent links in this application is shown.

[0024] Figure 9B It shows Figure 9A Schematic diagram of the cross section along the AA direction.

[0025] Figure 9C It shows Figure 9B A schematic diagram at point Q4.

[0026] Figure 9D A schematic diagram showing the angle between the first and second limiting surfaces of two adjacent chain links flush with each other.

[0027] Figure 10A A partial schematic diagram showing the bottom film pressing the wafer on the polishing unit before the adjustment of the clamping device.

[0028] Figure 10B A partial schematic diagram showing the bottom film pressing the wafer on the polishing unit after the adjustment of the clamping device.

[0029] Figure 10C A schematic diagram showing the pressure curve comparison of the wafer at different radial positions during the chemical mechanical polishing before and after the adjustment of the clamping device.

[0030] Figure 11 A schematic diagram showing an optional chemical mechanical polishing device in the present application. DETAILED DESCRIPTION

[0031] In order to make the person skilled in the art better understand the technical solutions in the present application, the technical solutions in the present application will be described clearly and completely in the present application by combining the drawings in the present application. Obviously, the described embodiments are only some of the embodiments in the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art should belong to the scope of protection of the present application.

[0032] The specific implementation of the polishing head 100 and the chemical mechanical polishing device 200 in the present application will be described below by combining the drawings. It should be noted that in order to facilitate the illustration, the structures in the following drawings are not necessarily drawn according to the actual proportions.

[0033] Referring to Figure 1 and Figure 2 , according to an aspect of the present application, a polishing head 100 for a chemical mechanical polishing device 200 is provided.

[0034] The polishing head 100 comprises a polishing head body 1, an elastic air film 2, a first clamping device 3 and a second clamping device 4. One end of the polishing head body 1 is formed with a mounting space 11, the elastic air film 2 is arranged in the mounting space 11, and the elastic air film 2 forms a side film 21 and a bottom film 22 away from the bottom of the mounting space 11.

[0035] The first clamping device 3 is in contact with the inner side of the side film 21, and the second clamping device 4 is in contact with the outer side of the side film 21. The first clamping device 3 and the second clamping device 4 cooperate to clamp the side film 21. In the state of clamping the side film 21, the first clamping device 3 and the second clamping device 4 are annular structures, and the circumferential dimensions of the annular structures of the first clamping device 3 and the second clamping device 4 can be adjusted to adjust the circumferential dimension of the elastic air film 2, so as to change the edge stress of the polished wafer.

[0036] The polishing head 100 in the present application will be described in detail below.

[0037] The polishing head 100 in the present application can be used in a chemical mechanical polishing device 200 and can be an important part of wafer picking and chemical mechanical polishing. In the present application, the chemical mechanical polishing device 200 can include one or more polishing heads 100, which are not limited herein. For example, the number of polishing heads 100 can correspond to the number of polishing units 201 (for example, can include polishing discs with polishing pads) of the chemical mechanical polishing device 200, and one polishing head 100 can be provided for each polishing unit 201. Alternatively, multiple polishing heads 100 can be provided for each polishing unit 201.

[0038] In the present application, the polishing head body 1 is the main part of the polishing head 100. One end of the polishing head body 1 is formed with a mounting space 11, for example, the mounting space 11 can be located at one end of the polishing head body 1 in the axial direction. Alternatively, as shown in Figure 1 The lower part of the polishing head body 1 is provided with a retaining ring 12, and the mounting space 11 can be surrounded by the retaining ring 12. The inner wall of the retaining ring 12 forms the side wall of the mounting space 11. The elastic air film 2 is arranged in the mounting space 11 and can be limited in position by the mounting space 11. The elastic air film 2 can be made of relatively soft rubber with elasticity. The elastic air film 2 forms a side film 21 and a bottom film 22 away from the bottom of the mounting space 11 in the mounting space 11. The polishing head 100 can absorb the wafer from the loading cup of the chemical mechanical polishing device 200 through the elastic air film 2 to take out the wafer. When the wafer is absorbed, the wafer is located in the mounting space 11 and in contact with the bottom film 22. Then the polishing head 100 can move the wafer to the polishing unit 201 (for example, can include polishing discs with polishing pads), and the bottom film 22 of the elastic air film 2 transmits pressure to the wafer to press the wafer on the polishing unit 201 of the chemical mechanical polishing device 200 for corresponding chemical mechanical polishing. The principle of the bottom film 22 transmitting pressure to the wafer can be to transmit gas pressure, for example, as shown in Figure 1 The inside of the elastic air film 2 is formed with a plurality of air chambers 23. The pressure transmitted by the bottom film 22 to each area of the wafer corresponding to the plurality of air chambers 23 can be reasonably adjusted by adjusting the gas pressure of the plurality of air chambers 23, so as to facilitate the chemical mechanical polishing of the wafer on the polishing pad.

[0039] In the present application, with reference to Figure 1 and Figure 2 , the first clamping device 3 is located at the inner side of the side film 21 of the elastic air film 2 and is in contact with the inner side of the side film 21, and the second clamping device 4 is located at the outer side of the side film 21 of the elastic air film 2 and is in contact with the outer side of the side film 21; through the cooperation of the first clamping device 3 and the second clamping device 4, the side film 21 can be clamped, thereby maintaining the rigidity of the side film 21 and improving the stability of the elastic air film 2.

[0040] The first clamping device 3 and the second clamping device 4 have a certain strength. In the state that the side film 21 is clamped by the first clamping device 3 and the second clamping device 4, the first clamping device 3 and the second clamping device 4 are annular structures, the annular structure of the first clamping device 3 can outwardly support the side film 21, and the annular structure of the second clamping device 4 can inwardly hoop the side film 21, so as to clamp the side film 21.

[0041] Optionally, with reference to Figure 1 and Figure 2 , the outer side of the annular structure of the first clamping device 3 can be attached to the inner side of the side film 21, and the inner side of the annular structure of the second clamping device 4 can be attached to the outer side of the side film 21, so as to clamp the side film 21. Based on this, the side film 21 can be effectively outwardly supported by the first clamping device 3 and inwardly hooped by the second clamping device 4, thereby effectively meeting the requirement that the first clamping device 3 and the second clamping device 4 cooperate to clamp the side film 21.

[0042] In the present application, the annular structures of the first clamping device 3 and the second clamping device 4 can be made and adapted according to the actual shape of the elastic air film 2. Optionally, the annular structures of the first clamping device 3 and the second clamping device 4 can both be circular ring structures. For example, the bottom film 22 of a conventional elastic air film 2 can be circular to adapt to the requirement of taking out wafers which are mostly circular. Therefore, the circular-shaped first clamping device 3 and the second clamping device 4 can also better adapt to such requirements.

[0043] The circumferential dimensions of the annular structures of the first clamping device 3 and the second clamping device 4 can be adjusted, so that by adjusting the circumferential dimensions of the annular structures of the first clamping device 3 and the second clamping device 4, the clamping state of the side film 21 of the elastic air film 2 can be adjusted, so as to change the circumferential dimension of the elastic air film 2, thereby changing the edge stress of the polished wafer, so that the elastic air film 2 can be applied to the polishing of trim wafers of different specifications.

[0044] The first clamping device 3 and the second clamping device 4 in the present application can be configured into any structure as long as the requirements are met. In some optional embodiments, the first clamping device 3 can be configured into a first type structure, and the second clamping device 4 can be configured into the first type structure or a second type structure.

[0045] Referring to Figure 3 , the first type structure includes at least one adjusting structure and at least one arc-shaped plate body 31, the at least one adjusting structure is connected to the at least one arc-shaped plate body 31, and the at least one arc-shaped plate body 31 is connected into a ring-shaped structure through the at least one adjusting structure, and the circumferential size of the ring-shaped structure is adjusted through the at least one adjusting structure.

[0046] Referring to Figure 7 , the second type structure includes a plurality of links 41 and a plurality of rotating shafts 42, the plurality of links 41 are sequentially and rotatably connected into a ring-shaped structure through the plurality of rotating shafts 42, and the circumferential size of the ring-shaped structure is adjusted by changing the number of the links 41 connected into the ring-shaped structure.

[0047] In the present application, the circumferential size of the ring-shaped structure of the first clamping device 3 and the second clamping device 4 can be effectively adjusted through the first type structure of the first clamping device 3 and the first type structure or the second type structure of the second clamping device 4, so that the clamping state of the side membrane 21 of the elastic air membrane 2 can be adjusted by adjusting the circumferential size of the ring-shaped structure of the two, thereby changing the edge stress of the polished wafer, so that the elastic air membrane 2 can be applied to wafers of different specifications.

[0048] It should be noted that the first clamping device 3 cannot adopt the second type structure because the second type structure cannot well outwardly support the side membrane 21 of the elastic air membrane 2, resulting in poor clamping effect. The second clamping device 4 inwardly clamps the side membrane 21, and the second type structure can well meet the requirements.

[0049] In the present application, for any first type structure, the arc-shaped plate body 31 has a certain strength, and the arc-shaped plate body 31 can be made of any suitable material, for example, can be made of metal material or reinforced plastic material.

[0050] In the present application, the specific implementation of the first type structure is not limited, and a suitable structure can be made as needed. Some optional implementations of the first type structure in the present application are described below.

[0051] Optionally, referring to Figure 3 , Figure 4 and Figure 5As shown, an optional first type structure is shown. In the optional first type structure: the arc-shaped plate body 31 comprises two overlapping portions for fastening, the two overlapping portions are located at two ends of the arc-shaped plate body 31, and the overlapping portions are provided with a plurality of lock holes 311; the adjusting structure comprises an arc-shaped lock buckle 32, the arc-shaped lock buckle 32 is buckled into the plurality of lock holes 311 on the two overlapping portions to connect at least one arc-shaped plate body 31 into a ring-shaped structure; the circumferential size of the ring-shaped structure can be adjusted by buckling the arc-shaped lock buckle 32 into different plurality of lock holes 311.

[0052] In the present application, when the first clamping device 3 and / or the second clamping device 4 adopts such a first type structure, the circumferential size adjustment of the ring-shaped structure of the first clamping device 3 and / or the second clamping device 4 can be effectively realized to facilitate the adjustment of the clamping state of the side membrane 21 of the elastic air membrane 2.

[0053] The lock hole 311 can be set to any suitable shape as needed. For example, it can be set to a parallelogram (in particular, it can be set to a rectangle). Or it can also be other regular or irregular shapes. Alternatively, when the lock hole 311 is set to a non-rectangular parallelogram, a certain range of slope can be set. The number of lock holes 311 on the arc-shaped plate body 31 can be set as needed and is not limited herein. In addition, the spacing between adjacent lock holes 311 on each overlapping portion can also be set as needed to meet different adjustment needs.

[0054] In some optional embodiments, referring to Figure 5 As shown, the arc-shaped plate body 31 further comprises a main body portion which is arranged between the overlapping portions. Among them, the thickness of the overlapping portion is less than or equal to half of the thickness of the main body portion. Based on this, the thickness of the two overlapping portions after overlapping can be avoided to be too large, and the thickness uniformity of the first clamping device 3 and / or the second clamping device 4 after forming a ring-shaped structure can be improved.

[0055] In this optional first type structure, a single or multiple arc-shaped plate bodies 31 can be included, i.e., a single or multiple arc-shaped plate bodies 31 can be used to form a ring-shaped structure.

[0056] Alternatively, referring to Figure 3 As shown, if a single arc-shaped plate body 31 and a single adjusting structure are included in the first type structure, the arc-shaped lock buckle 32 of the single adjusting structure is buckled into the plurality of lock holes 311 on the two overlapping portions of the single arc-shaped plate body 31 to form a ring-shaped structure. Through such a structure, the single arc-shaped plate body 31 can be effectively connected into a ring-shaped structure by the arc-shaped lock buckle 32 and the plurality of lock holes 311 of the single adjusting structure, and the circumferential size of the ring-shaped structure can be effectively adjusted.

[0057] Optionally, if the first type of structure includes multiple arc-shaped plates 31 and multiple adjustment structures, the multiple arc-shaped plates 31 are connected sequentially through multiple adjustment structures. Furthermore, the arc-shaped latches 32 of the adjustment structures connecting each pair of adjacent arc-shaped plates 31 engage with multiple locking holes 311 on the first overlapping portion of the first arc-shaped plate 31 and the second overlapping portion of the second arc-shaped plate 31 in the two adjacent arc-shaped plates 31, thus forming a ring structure. With this structure, the multiple arc-shaped plates 31 can be effectively connected into a ring structure through the arc-shaped latches 32 and multiple locking holes 311 of the multiple adjustment structures, and the circumferential dimension adjustment of the ring structure can be effectively achieved.

[0058] For example, if it includes four arc-shaped plates 31 and four arc-shaped latches 32, its structure can be as follows: the second overlapping portion of the first arc-shaped plate 31 and the first overlapping portion of the first arc-shaped plate 31 are connected by the first arc-shaped latch 32 after overlapping; the second overlapping portion of the second arc-shaped plate 31 and the first overlapping portion of the third arc-shaped plate 31 are connected by the second arc-shaped latch 32 after overlapping; the second overlapping portion of the third arc-shaped plate 31 and the first overlapping portion of the fourth arc-shaped plate 31 are connected by the third arc-shaped latch 32 after overlapping; the second overlapping portion of the fourth arc-shaped plate 31 and the first overlapping portion of the first arc-shaped plate 31 are connected by the fourth arc-shaped latch 32 after overlapping; thus forming a ring structure. The number of other arc-shaped plates 31 and adjustment structures can be deduced similarly, and will not be elaborated here.

[0059] This application does not limit the specific structure of the arc-shaped latch 32. In some alternative embodiments, refer to Figure 4 As shown, the arc-shaped latch 32 includes a locking piece 323, a setting hole 324, and a first arc wall 321 and a second arc wall 322 located on both sides of the setting hole 324 along the thickness direction of the arc-shaped latch 32. The thickness of the first arc wall 321 is greater than the thickness of the second arc wall 322. Two overlapping portions are intersected in the setting hole 324, so that the first arc wall 321 and the second arc wall 322 are located on both sides of the two overlapping portions. The locking piece 323 of the arc-shaped latch 32 engages with a plurality of locking holes 311 on the two overlapping portions of the setting hole 324 to connect at least one arc-shaped plate 31 into a ring structure. Wherein, if the first clamping device 3 is a first type structure, the first arc wall 321 is located on the inner side of the ring structure and the second arc wall 322 is located on the outer side of the ring structure; if the second clamping device 4 is a first type structure, the second arc wall 322 is located on the inner side of the ring structure and the first arc wall 321 is located on the outer side of the ring structure.

[0060] Based on the above-mentioned optional arc-shaped lock 32 structure, at least one arc-shaped plate body 31 can be effectively connected into an arc shape through the plurality of lock holes 311. In addition, when the first clamping device 3 adopts such a structure, the first arc wall 321 with a larger thickness is located on the inner side of the annular structure, and the second arc wall 322 with a smaller thickness is located on the outer side of the annular structure, so that the second arc wall 322 with a smaller thickness is in contact with the inner side of the side film 21 of the elastic air film 2. Thus, by adopting such a structure, the arc-shaped plate body 31 of the first clamping device 3 can better realize the fit with the side film 21, so as to improve the clamping effect.

[0061] In addition, when the second clamping device 4 adopts such a structure, the first arc wall 321 with a larger thickness is located on the outer side of the annular structure, and the second arc wall 322 with a smaller thickness is located on the inner side of the annular structure, so that the second arc wall 322 with a smaller thickness is in contact with the outer side of the side film 21 of the elastic air film 2. Thus, by adopting such a structure, the arc-shaped plate body 31 of the second clamping device 4 can better realize the fit with the side film 21, so as to improve the clamping effect.

[0062] Optionally, the first arc wall 321 and the second arc wall 322 and the arc-shaped plate body 31 are in a circular arc structure, and the circular arcs are in the same direction. In this way, the effect of the annular structure formed can be better.

[0063] For example, referring to Figure 3 In the first type structure shown in FIG. 1, the first arc wall 321 with a larger thickness is located on the outer side of the annular structure, and the second arc wall 322 with a smaller thickness is located on the inner side of the annular structure, so that the first arc wall 321 with a larger thickness is not in direct contact with the side film 21. Figure 6

[0064] For example, referring to Figure 7 and Figure 8 In the second type structure, the link 41 includes a main body part 411 and an extension part 412, the extension part 412 is connected to one side of the main body part 411 along the width direction, and the other side of the main body part 411 along the width direction is provided with a notch 413; the extension part 412 is provided with a first shaft hole, and the two sides of the notch 413 of the main body part 411 are respectively provided with a second shaft hole and a third shaft hole; in the adjacent two links 41, the extension part 412 of the first link 41 is arranged in the notch 413 of the second link 41, and the shaft 42 is sequentially arranged in the second shaft hole, the first shaft hole and the third shaft hole,

[0065] so as to rotatably connect the adjacent two links 41.

[0066] ​Based on this, two chain links 41 are rotatably connected through the rotating shaft 42, so that the plurality of chain links 41 and the plurality of rotating shafts 42 are connected into a ring structure, and the circumferential size of the ring structure can be adjusted by changing the number of chain links 41.

[0067] Optionally, the extension part 412 extends from the main body part 411, and the two are connected in an integrally formed structure.

[0068] Optionally, as shown in Figure 9A and Figure 9B , the chain link 41 in the present application can include a first limiting surface B and a second limiting surface C, wherein the first limiting surface B is located at the extension part 412 of the chain link 41, and the second limiting surface C is located at the gap 413 of the chain link 41; and in the optional second type structure, as shown in Figure 9A to 9C , in some states, among the two adjacent chain links 41, the first limiting surface B of one chain link 41 can be limited by the second limiting surface C of the other chain link 41, so that the rotation angle of the chain link 41 relative to the other chain link 41 cannot be too large, thereby preventing the ring structure connected finally from deforming too much.

[0069] Optionally, as shown in Figure 9D , when the two adjacent chain links 41 are flush, the included angle between the first limiting surface B of the first chain link 41 and the second limiting surface C of the second chain link 41 is θ, and θ = 360° / a, wherein a is the minimum number of chain links 41 when the first limiting surface B on the extension part 412 of each chain link 41 in the second type structure is limited by the second limiting surface C at the gap 413 of the adjacent other chain link 41. That is, when θ = 360° / a, then the second type structure connected into a ring structure requires at least a chain link 41; if the circumferential size of the ring structure needs to be increased, the number of chain links 41 needs to be increased. Through such a structure, the present application can prevent the overall deformation of the ring structure of the optional second type structure from being too large.

[0070] It should be noted that the above optional first type structure and second type structure can be selected and used as needed, and the first clamping device 3 and the second clamping device 4 can select the same first type structure or different first type structures, as long as they can meet the use requirements.

[0071] The present application will be understood in combination with Figure 10A , Figure 10B and Figure 10C . As shown in Figure 10A and Figure 10B , the wafer 300 is a trim wafer, and the thickness of the edge is smaller than the thickness of the inside. Figure 10AFig. 1 shows a state before the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 10B Fig. 2 shows a state after the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted.

[0072] Fig. 1 shows a state before the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 10A Fig. 1 shows a state before the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 10C Fig. 1 shows a state before the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 10A Fig. 1 shows a state before the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted.

[0073] Fig. 1 shows a state before the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 10B Fig. 2 shows a state after the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 10C Fig. 2 shows a state after the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 10B Fig. 2 shows a state after the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted.

[0074] Fig. 2 shows a state after the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted. Figure 11 Fig. 2 shows a state after the circumferential dimension of the annular structure of the clamping device (i.e. the first clamping device 3 and the second clamping device 4) is adaptively adjusted.

[0075] For example, in some optional embodiments, the polishing unit 201 can include a polishing disc with a polishing pad, the polishing disc can drive the polishing pad to rotate, the bottom film 22 of the polishing head 100 can transmit pressure to the wafer to press the wafer on the polishing pad of the polishing disc, and the wafer is chemically and mechanically polished by the polishing pad. Optionally, the polishing head 100 needs to drive the wafer to rotate during chemical mechanical polishing. In addition, the polishing unit 201 also needs to be configured with a liquid supply device, which drips polishing liquid used for chemical mechanical polishing on the polishing pad during chemical mechanical polishing. Optionally, the polishing unit 201 can also include a trimming device, which trims the polishing pad to improve the effect of chemical mechanical polishing.

[0076] In some optional embodiments, the chemical mechanical polishing apparatus 200 also includes a loading cup for carrying the wafer, and the polishing head 100 can interact with the loading cup to load the wafer. Optionally, the elastic air film 2 can take the wafer away from the loading cup by adsorbing the wafer. It should be understood that the above-mentioned polishing unit 201 and the loading cup for carrying the wafer can be realized as any suitable structure, and can also be understood with reference to the related art, which will not be described here.

[0077] Since the chemical mechanical polishing apparatus 200 in the present application uses at least one polishing head 100 as described above, when different specifications and sizes of trim wafers are chemically and mechanically polished, the steep increase of the polishing rate of the wafer edge is improved, and the effect of chemical mechanical polishing is improved.

[0078] Since the polishing head 100 can adapt to wafers of different specifications and sizes by adjusting the circumferential size of the annular structure of the first clamping device and the second clamping device, the chemical mechanical polishing apparatus 200 also does not need to design different elastic air films and polishing heads for wafers of different specifications and sizes, thereby effectively reducing the complexity of polishing head management, reducing the workload of researchers in research and development, and reducing the difficulty of cost control.

[0079] It should be noted that the scheme / apparatus provided in the present application is mainly applied to chemical mechanical polishing of wafers of third-generation semiconductor materials, and can be specifically used for 4-inch, 6-inch or 8-inch wafers processed from third-generation semiconductor materials, such as 4-inch, 6-inch or 8-inch GaN wafers, or 8-inch SiC wafers, etc.

[0080] In addition, since the growth of third-generation semiconductor materials is difficult, there are problems such as difficulty in controlling the temperature field, slow growth speed, high requirement for good product parameters, and difficulty in expanding the diameter of the crystal, so the wafer size of the third-generation semiconductor material is mainly 6-8 inches. With the development of technology and the overcoming of growth problems, the wafer size of the third-generation semiconductor material can be expanded to 12 inches or even more than 12 inches, which is also applicable to the scheme / apparatus provided in the present application and is within the protection scope of the present application.

[0081] The optional embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application. The various technical features included in the various different embodiments of the present application can be combined in any suitable manner. In order to avoid unnecessary repetition, various possible combinations are not described again in the present application. However, these simple modifications and combinations should also be regarded as disclosed in the present application and fall within the protection scope of the present application.

[0082] The term “comprising” and variations thereof as used herein are open-ended, that is, “comprising but not limited to”. The term “based on” means “based at least in part on”. The term “one embodiment” means “at least one embodiment”; the term “another embodiment” means “at least one additional embodiment”; the term “some embodiments” means “at least some embodiments”. It should be noted that the concepts “first”, “second”, etc. mentioned in the present application are only used to distinguish different devices, modules or units, and do not limit the order or interdependence of the functions performed by these devices, modules or units. It should be noted that the terms “one”, “multiple” used in the present application are illustrative and not limiting, and those skilled in the art should understand that “one” or “multiple” should be understood as “one or more” unless otherwise explicitly indicated in the context.

[0083] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A polishing head for use in chemical mechanical polishing equipment, characterized in that, include: The polishing head body comprises an elastic air film, a first clamping device, and a second clamping device. One end of the polishing head body has an installation space, and the elastic air film is disposed within the installation space, forming a side film and a bottom film away from the bottom of the installation space. The first clamping device contacts the inner surface of the side membrane, and the second clamping device contacts the outer surface of the side membrane. The first clamping device and the second clamping device cooperate with each other to clamp the side membrane. When the side film is clamped, both the first clamping device and the second clamping device are annular structures, and the circumferential dimensions of the annular structures of the first clamping device and the second clamping device can be adjusted to adjust the circumferential dimensions of the elastic gas film and change the edge force of the polished wafer.

2. The polishing head according to claim 1, characterized in that, The outer side of the annular structure of the first clamping device is attached to the inner side of the side membrane, and the inner side of the annular structure of the second clamping device is attached to the outer side of the side membrane to clamp the side membrane.

3. The polishing head according to claim 1, characterized in that, The ring structure is a circular ring structure.

4. The polishing head according to any one of claims 1-3, characterized in that, The first clamping device is configured with a first type of structure, and the second clamping device is configured with either a first type of structure or a second type of structure; wherein... The first type of structure includes: at least one adjustment structure and at least one arc-shaped plate, wherein the at least one adjustment structure is connected to the at least one arc-shaped plate, and the at least one arc-shaped plate is connected to form a ring structure through the at least one adjustment structure, and the circumferential dimension of the ring structure is adjusted through the at least one adjustment structure; The second type of structure includes: multiple links and multiple pivots, wherein the multiple links are rotatably connected in sequence to form a ring structure, and the circumferential dimension of the ring structure can be adjusted by adjusting the number of links.

5. The polishing head according to claim 4, characterized in that, In the first type of structure: The arc-shaped plate includes two overlapping portions for fixing, located at both ends of the arc-shaped plate, and the overlapping portions are provided with multiple locking holes; The adjustment structure includes an arc-shaped latch that can engage with the locking holes of two overlapping portions to connect at least one arc-shaped plate into a ring structure. The circumferential dimensions of the annular structure can be adjusted by adjusting the arc-shaped latch to engage with different lock holes.

6. The polishing head according to claim 5, characterized in that, If the first type of structure includes a single arc-shaped plate and a single adjustment structure, then the arc-shaped latch of the single adjustment structure is engaged with the locking hole of the overlapping part of the single arc-shaped plate to form the ring structure; If the first type of structure includes multiple arc-shaped plates and multiple adjustment structures, the multiple arc-shaped plates are connected sequentially through multiple adjustment structures, and the arc-shaped latch of the adjustment structure connecting each two adjacent arc-shaped plates is engaged in the locking hole of the first overlapping part of the first arc-shaped plate and the second overlapping part of the second arc-shaped plate in the two adjacent arc-shaped plates to form the ring structure.

7. The polishing head according to claim 5, characterized in that, The arc-shaped plate also includes a main body portion located between the overlapping portions, wherein the thickness of the overlapping portions is less than or equal to half the thickness of the main body portion.

8. The polishing head according to claim 5, characterized in that, The arc-shaped latch includes a locking plate, a setting hole, and a first arc wall and a second arc wall located on both sides of the setting hole along the thickness direction of the arc-shaped latch, wherein the thickness of the first arc wall is greater than the thickness of the second arc wall.

9. The polishing head according to claim 8, characterized in that, The two overlapping portions are intersected and pass through the setting hole, so that the first arc wall and the second arc wall are respectively located on both sides of the two overlapping portions; The locking plate of the arc-shaped latch engages with the locking holes of the two overlapping portions of the setting hole, so as to connect the at least one arc-shaped plate into a ring structure.

10. The polishing head according to claim 9, characterized in that, If the first clamping device is of the first type of structure, then the first arc wall is located inside the annular structure, and the second arc wall is located outside the annular structure; If the second clamping device is of the first type, then the second arc wall is located inside the annular structure, and the first arc wall is located outside the annular structure.

11. The polishing head according to claim 4, characterized in that, In the second type of structure: The link includes a main body and an extension, the extension being connected to one side of the main body along the width direction, and the other side of the main body along the width direction including a notch; The extension is provided with a first shaft hole, and the two sides of the notch in the main body are respectively provided with a second shaft hole and a third shaft hole; In two adjacent links, the extension of the first link is disposed in the notch of the second link, and the shaft is sequentially inserted through the second shaft hole, the first shaft hole and the third shaft hole to rotatably connect the two adjacent links.

12. A chemical mechanical polishing apparatus, characterized in that, include: A polishing unit, wherein the polishing unit is configured with a polishing head as described in any one of claims 1-11, wherein the elastic air film configured on the polishing head is adjustable in circumferential dimension by means of a first clamping device and a second clamping device to change the edge force of the polished wafer.

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