Adsorption device of polishing head, chemical mechanical polishing equipment and control method

Abstract

The present application discloses an adsorption device for a grinding head, a chemical mechanical grinding device and a control method, wherein the adsorption device comprises: an adsorption film made of an elastic material, the adsorption film having a first surface and a second surface relative to each other, the first surface being used to contact a wafer; wherein the wafer comprises a central area and an edge area surrounding the central area; the adsorption device further comprises an adsorption chamber and a plurality of pressure chambers arranged on the second surface, the adsorption chamber being used to adsorb the edge area; the plurality of pressure chambers being used to be respectively connected to an external pressure supply device, so that each pressure chamber can adjust the pressure therein through an independent pressure supply device, and adjust the pressure applied to the area on the central area opposite to the position of the pressure chamber; wherein some of the pressure chambers are arranged along the circumference of the wafer, and some of the pressure chambers are arranged along the radial direction of the wafer.

Description

Technical Field

[0001] The present application relates to the semiconductor field, and more specifically to an adsorption device for a polishing head, a chemical mechanical polishing device, and a control method. Background Art

[0002] Chemical Mechanical Polishing (CMP) technology was first introduced in wafer manufacturing. With the upgrade of process technology and the increase in requirements for wafer surface flatness, CMP technology has developed rapidly since the 1990s and has been widely used in the semiconductor industry. CMP technology achieves surface flatness by combining chemical etching and physical mechanical removal, becoming the only technology in mechanical processing that can achieve this goal.

[0003] The adsorption film is an important component in the CMP process. Its working principle is: the grinding head transfers the wafer to the grinding pad through the adsorption film. A pressure chamber is provided in the grinding head to provide pressure to the wafer so that there is pressure between the wafer and the grinding pad. As the grinding pad rotates, the global flattening of the wafer is achieved.

[0004] However, the structures of the adsorption film and the pressure chamber in the related art are relatively complicated, and the flatness of the ground wafer is relatively poor. Summary of the invention

[0005] The present application is proposed to solve the above-mentioned problems. According to one aspect of the present application, an adsorption device for a grinding head is provided, the adsorption device comprising: an adsorption film made of an elastic material, the adsorption film having a first surface and a second surface relative to each other, the first surface being used to contact a wafer; wherein the wafer comprises a central area and an edge area surrounding the central area; the adsorption device further comprises an adsorption chamber and a plurality of pressure chambers arranged on the second surface, the adsorption chamber being used to adsorb the edge area; the plurality of pressure chambers are used to be respectively connected to an external pressure supply device, so that each pressure chamber can adjust the pressure therein through an independent pressure supply device, and adjust the pressure applied to the area on the central area opposite to the position of the pressure chamber; wherein some of the pressure chambers are arranged along the circumference of the wafer, and some of the pressure chambers are arranged along the radial direction of the wafer.

[0006] The above embodiment has the following beneficial effects: by using an adsorption film made of elastic material, setting an adsorption chamber and a pressure chamber on the second surface of the adsorption film, and integrating the pressure chamber into the adsorption device, the adsorption film can be directly used as the cavity wall of the adsorption chamber and the pressure chamber facing the wafer side, and when the adsorption chamber is in a negative pressure state to adsorb the wafer, the adsorption film can be deformed toward the inside of the adsorption chamber; and when the pressure chamber is in a positive pressure state to apply pressure to the wafer, the adsorption film can be deformed toward the wafer direction, which can simplify the structural arrangement of the adsorption film, the pressure chamber and the adsorption chamber. Moreover, some pressure chambers are arranged along the circumference of the wafer, and some pressure chambers are arranged along the radial direction of the wafer, so that the grinding rates of different angle areas of the same radius area on the wafer can be adjusted separately, which is beneficial to improve the flatness of the same radius area of ​​the wafer.

[0007] In some embodiments of the present application, the adsorption device also includes: a support plate spaced apart from the second surface of the adsorption membrane, wherein the adsorption chamber and the pressure chamber are arranged between the adsorption membrane and the support plate; the pressure chamber includes: a first bottom chamber wall formed by the adsorption membrane, a first top chamber wall formed by the support plate, and a first side chamber wall connected between the first bottom chamber wall and the first top chamber wall; the adsorption chamber includes: a second bottom chamber wall formed by the adsorption membrane, a second top chamber wall formed by the support plate, and a second side chamber wall connected between the second bottom chamber wall and the second top chamber wall.

[0008] The above-mentioned embodiment has the following beneficial effects: by setting a rigid support plate, it is convenient to connect the adsorption device to the grinding head, and when the pressure state in the adsorption chamber and the pressure chamber changes, the rigid support plate will not deform or the deformation amount is extremely small, thereby not interfering with the influence of the adsorption device on other devices in the grinding head; by setting the adsorption chamber and the pressure chamber between the support plate and the adsorption membrane, and making the support plate and the adsorption membrane serve as the top cavity wall and the bottom cavity wall of each chamber respectively, the structure of the adsorption device is simplified.

[0009] In some embodiments of the present application, the first side cavity wall includes: a partition formed by extending from the support plate toward the adsorption membrane, and a diaphragm formed by extending from the adsorption membrane toward the support plate; wherein the partition and the diaphragm are sealed and connected.

[0010] The above embodiment has the following beneficial effects: for the first side wall of the pressure chamber, it is composed of a rigid partition and an elastic diaphragm, and the partition is originally arranged in the direction of the wafer, and the diaphragm is arranged close to the direction of the wafer, so that when there is a pressure difference between two adjacent pressure chambers, the diaphragm will have a slight deformation toward the side with smaller pressure, thereby increasing the transition area on the wafer partitions corresponding to the two pressure chambers, slowing down the sudden change in pressure between different partitions on the wafer, and slowing down the sudden change in grinding rate at the connection between different partitions of the wafer, which is beneficial to improving the flatness of the connection between different partitions of the wafer.

[0011] In some embodiments of the present application, the height of the diaphragm accounts for one third to two thirds of the total height of the first side cavity wall.

[0012] The above embodiment has the following beneficial effects: if the height of the diaphragm accounts for more than two-thirds of the total height of the first side cavity wall, when there is a pressure difference between two adjacent pressure chambers, the deformation amount of the diaphragm toward the side with smaller pressure will be larger, thereby significantly reducing the pressure difference between the two pressure chambers, which is not conducive to independent and obvious adjustment of the pressure applied to different partitions of the wafer; if the height of the diaphragm accounts for less than one-third of the total height of the first side cavity wall, when there is a pressure difference between two adjacent pressure chambers, the deformation amount of the diaphragm toward the side with smaller pressure is almost small, and the increase in the area of ​​the transition area on the wafer partitions corresponding to the two pressure chambers is very small, and the effect of slowing down the sudden change of the grinding rate at the connection between different partitions of the wafer is small, which is not conducive to improving the flatness of the connection between different partitions of the wafer. By controlling the height of the diaphragm to one-third to two-thirds of the total height of the first side cavity wall, it is not only conducive to independent and obvious adjustment of the pressure applied to different partitions of the wafer, but also conducive to improving the flatness of the connection between different partitions of the wafer.

[0013] In some embodiments of the present application, the second side cavity wall includes: a first annular baffle and a second annular baffle formed by extending from a support plate to the second surface in the direction of the adsorption membrane; wherein the size of the first annular baffle is larger than the size of the second annular baffle, and the first annular baffle is concentrically arranged with the second annular baffle; the first annular baffle and the second annular baffle are both sealed and connected to the second surface of the adsorption membrane; and a portion of the first side cavity wall of the pressure chamber adjacent to the second annular baffle is formed by the second annular baffle.

[0014] The above embodiment has the following beneficial effects: by adopting a rigid first annular baffle and a second annular baffle to form the second side cavity wall of the adsorption chamber, when the adsorption chamber is in a negative pressure state and the pressure chamber adjacent to it is in a positive pressure state, the second annular baffle will not deform or the deformation amount will be extremely small, so that the adsorption chamber will not interfere with the normal pressure regulation function of the adjacent pressure chamber; and the first annular baffle will not deform or the deformation amount will be extremely small, so as not to interfere with the normal operation of other structures in the grinding head.

[0015] In some embodiments of the present application, the diaphragm and the partition are connected in a detachable sealed manner; and the first annular partition and the second annular partition are connected in a detachable sealed manner to the second surface of the adsorption membrane.

[0016] The above embodiment has the following beneficial effects: the diaphragm and the partition plate are detachably sealed and connected, and the two annular partition plates and the second surface of the adsorption membrane are detachably sealed and connected, so that the adsorption membrane can be easily replaced.

[0017] In some embodiments of the present application, the area of ​​the first bottom cavity wall does not exceed a preset value.

[0018] The above embodiment has the following beneficial effects: by controlling the area of ​​the first bottom cavity wall not to exceed a preset value, the area of ​​the pressure adjustment zone of a single pressure chamber is made very small, and the area of ​​the partition relative to the position of each pressure chamber on the wafer is reduced, so that the pressure of different areas of the wafer can be finely adjusted, which is beneficial to reduce the difference in grinding rate between adjacent different partitions and improve the flatness of the ground wafer.

[0019] In some embodiments of the present application, the multiple pressure chambers include: at least two fan-shaped chambers that enclose a circular area; and at least two fan-shaped annular chambers that enclose at least one annular area; and the circular area and all the annular areas are concentrically arranged.

[0020] The above-mentioned embodiment has the following beneficial effects: by adopting a circular area enclosed by at least two fan-shaped chambers, and at least two fan-shaped annular chambers enclosed by at least one annular area, the wafer is partitioned according to the radius range and angle range, thereby providing more controllable pressure chambers; based on the angle partitioning method, during the pressure control process, independent pressures can be given to pressure chambers at different angles at the same radius, thereby improving the flatness of the same radius area of ​​the wafer.

[0021] According to the second aspect of the present application, a chemical mechanical polishing device is also provided, which includes: a polishing pad, a polishing liquid supplier, a pressure supply device and a polishing head; wherein the polishing liquid supplier is used to spray polishing liquid onto the polishing pad; the polishing head includes an adsorption device of any one of the above-mentioned polishing heads, and multiple pressure chambers are respectively connected to an external pressure supply device.

[0022] According to the third aspect of the present application, a control method for an adsorption device based on any of the above-mentioned grinding heads is also provided, and the control method includes: after the wafer to be ground is adsorbed on the grinding head through the adsorption chamber, obtaining the target grinding amount of the area on the wafer to be ground corresponding to the position of each pressure chamber; based on the target grinding amount, dividing multiple pressure chambers into at least two adjustment groups; based on the target grinding amount corresponding to each adjustment group, determining the target pressure of each adjustment group; based on the target pressure of each adjustment group, controlling the pressure supply device to supply pressure to each pressure chamber.

[0023] The above embodiment has the following beneficial effects: some of the multiple pressure chambers on the grinding head are arranged along the circumference of the wafer, and some are arranged along the radial direction of the wafer, so that the grinding rates of different angle areas of the same radius area on the wafer can be adjusted separately, which is beneficial to improving the flatness of the same radius area of ​​the wafer. And by obtaining the target grinding amount of the area on the wafer to be ground that is opposite to the position of each pressure chamber, and dividing the multiple pressure chambers into at least two adjustment groups based on the target grinding amount, and then determining the target pressure of each adjustment group based on the target grinding amount corresponding to each adjustment group. By applying the same target pressure to the adjustment groups corresponding to the areas with similar or identical target grinding amounts, the grinding rates of the areas corresponding to the same adjustment group on the wafer can be made the same, which is beneficial to the final grinding degree of the areas with similar or identical target grinding amounts to be similar or identical, which is beneficial to improving the flattening effect of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 A schematic cross-sectional view of the structure of an adsorption device according to an embodiment of the present application;

[0026] Figure 2 A schematic top view of an adsorption device according to an embodiment of the present application;

[0027] Figure 3 This is a partially enlarged schematic diagram of an adsorption device shown in one embodiment of the present application;

[0028] Figure 4 A schematic diagram of a first surface of an adsorption device according to an embodiment of the present application;

[0029] Figure 5 A schematic top view and a schematic cross-sectional view of a certain cross section of a pressure chamber shown in one embodiment of the present application;

[0030] Figure 6 A schematic top view of a pressure chamber shown in another embodiment of the present application;

[0031] Figure 7 A schematic cross-sectional view of a pressure chamber according to an embodiment of the present application;

[0032] Figure 8 A schematic diagram of the arrangement of a pressure chamber according to an embodiment of the present application;

[0033] Fig. 9A schematic diagram showing that the flatness of wafers polished by existing chemical mechanical polishing equipment is poor;

[0034] Fig.10 A schematic flow chart of a method for controlling a grinding head according to an embodiment of the present application;

[0035] Fig.11 A schematic diagram of a process for determining a target grinding amount according to an embodiment of the present application;

[0036] Fig.12 A schematic diagram of a process for dividing adjustment groups according to an embodiment of the present application;

[0037] Fig.13 This is a schematic diagram of a flow chart for determining a target pressure for each adjustment group according to an embodiment of the present application.

[0038] Reference numerals:

[0039] 10-adsorption film 20-wafer

[0040] 21-Central area 22-Edge area

[0041] 30-adsorption chamber 31-second bottom chamber wall

[0042] 32-second top cavity wall 33-first annular partition

[0043] 34- Second annular partition 40- Pressure chamber

[0044] 41-first bottom cavity wall 42-first top cavity wall

[0045] 43- partition 44- diaphragm

[0046] 50-support plate 60-connecting pipe DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0048] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0049] It should be understood that the present application can be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0050] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, confirm the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0051] In order to thoroughly understand the present application, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present application. The optional embodiments of the present application are described in detail as follows, but in addition to these detailed descriptions, the present application may also have other implementation methods.

[0052] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0053] First, the application scenario of the adsorption device of the grinding head shown in the example of this application is introduced. The grinding head is a device used to adsorb, move and clamp the wafer when the wafer is subjected to chemical mechanical grinding; the adsorption device of the grinding head is used to adsorb the wafer on the grinding head, and is also used to independently apply pressure to different partitions on the wafer to adjust the grinding rate of different partitions of the wafer.

[0054] refer to Figure 1 , Figure 2 and Figure 3The embodiment of the present application provides an adsorption device for a grinding head, the adsorption device comprising: an adsorption film 10 made of an elastic material, the adsorption film 10 having a first surface and a second surface relative to each other, the first surface being used to contact a wafer 20; wherein the wafer 20 comprises a central area 21 and an edge area 22 surrounding the central area 21; the adsorption device further comprises an adsorption chamber 30 and a plurality of pressure chambers 40 arranged on the second surface, the adsorption chamber 30 being used to adsorb the edge area 22; the plurality of pressure chambers 40 are used to be respectively connected to an external pressure supply device, so that each pressure chamber 40 can adjust the pressure therein through an independent pressure supply device, and adjust the pressure applied to the area on the central area 21 opposite to the pressure chamber 40; wherein some of the pressure chambers 40 are arranged along the circumferential direction of the wafer 20, and some of the pressure chambers 40 are arranged along the radial direction of the wafer 20.

[0055] The above embodiment has the following beneficial effects: by using an adsorption film 10 made of elastic material, setting an adsorption chamber 30 and a pressure chamber 40 on the second surface of the adsorption film 10, and integrating the pressure chamber 40 in the adsorption device, the adsorption film 10 can be directly used as the cavity wall of the adsorption chamber 30 and the pressure chamber 40 facing the wafer 20. When the adsorption chamber 30 is in a negative pressure state to adsorb the wafer 20, the adsorption film 10 can deform toward the inside of the adsorption chamber 30; and when the pressure chamber 40 is in a positive pressure state to apply pressure to the wafer 20, the adsorption film 10 can deform toward the wafer 20, which can simplify the structural arrangement of the adsorption film 10, the pressure chamber 40 and the adsorption chamber 30. Moreover, part of the pressure chamber 40 is arranged along the circumference of the wafer 20, and part of the pressure chamber 40 is arranged along the radial direction of the wafer 20, so that the grinding rate of different angle areas of the same radius area on the wafer 20 can be adjusted separately, which is beneficial to improve the flatness of the same radius area of ​​the wafer 20. The above structures are described in detail below in conjunction with the accompanying drawings.

[0056] The existing method of dividing the pressure chamber 40 into multiple circular / annular areas according to the radius causes deformation at the junction of each partition, resulting in a sudden change in pressure in the transition area, which ultimately affects the flattening effect. The existing method cannot solve the problem of different grinding amounts required at different angles in the same radius area, which results in thickness deviation of the wafer 20 after grinding.

[0057] The current arrangement of the pressure chamber 40 is based on the radius arrangement in a ring shape, referring to Fig. 9 When the thickness of the wafer 20 is offset, the current arrangement of the pressure chambers 40 cannot achieve accurate regional pressure control. The adsorption device shown in the present application can provide different pressures to each pressure chamber 40 in the same annular area to adjust the grinding rate of different areas, thereby solving the defect of the thickness of the wafer 20 being offset and improving the flatness of the wafer 20.

[0058] When setting the adsorption film 10, refer to Figure 1 , the adsorption film 10 covers the surface of the grinding head, and the grinding head contacts the wafer 20 through the adsorption film 10 and provides pressure to the wafer 20. It should be noted that the central area 21 of the wafer 20 is an area for arranging microelectronic devices such as but not limited to transistors, capacitors, resistors, etc., and the edge area 22 of the wafer 20 is an area not used for arranging electronic devices.

[0059] In some embodiments, reference Figure 1 , Figure 3 , Figure 4 and Figure 7 The adsorption device may further include: a support plate 50 spaced apart from the second surface of the adsorption membrane 10, wherein the adsorption chamber 30 and the pressure chamber 40 are arranged between the adsorption membrane 10 and the support plate 50; the pressure chamber 40 includes: a first bottom chamber wall 41 formed by the adsorption membrane 10, a first top chamber wall 42 formed by the support plate 50, and a first side chamber wall connected between the first bottom chamber wall 41 and the first top chamber wall 42; the adsorption chamber 30 includes: a second bottom chamber wall 31 formed by the adsorption membrane 10, a second top chamber wall 32 formed by the support plate 50, and a second side chamber wall connected between the second bottom chamber wall 31 and the second top chamber wall 32.

[0060] The above-mentioned embodiment has the following beneficial effects: by setting a rigid support plate 50, it is convenient to connect the adsorption device to the grinding head, and when the pressure state in the adsorption chamber 30 and the pressure chamber 40 changes, the rigid support plate 50 will not deform or the deformation amount is extremely small, so as not to interfere with the influence of the adsorption device on other devices in the grinding head; by setting the adsorption chamber 30 and the pressure chamber 40 between the support plate 50 and the adsorption film 10, and making the support plate 50 and the adsorption film 10 serve as the top cavity wall and the bottom cavity wall of each cavity respectively, the structure of the adsorption device is simplified.

[0061] In some embodiments, reference Figure 1 and Figure 3 The first side cavity wall includes: a partition 43 formed by extending from the support plate 50 toward the adsorption membrane 10, and a diaphragm 44 formed by extending from the adsorption membrane 10 toward the support plate 50; wherein the partition 43 and the diaphragm 44 are sealed and connected.

[0062] The above embodiment has the following beneficial effects: the existing adsorption film 10 is insensitive to pressure feedback at the junction of each partition due to deformation difference. In the above embodiment of the present application, for the first side wall of the pressure chamber 40, it is composed of a rigid partition 43 and an elastic diaphragm 44, and the partition 43 is originally arranged in the direction of the wafer 20, and the diaphragm 44 is arranged close to the direction of the wafer 20, so that when there is a pressure difference between two adjacent pressure chambers 40, the diaphragm 44 will have a slight deformation toward the side with smaller pressure, so that the transition area area on the wafer 20 partition corresponding to the two pressure chambers 40 can be increased, the problem of insensitivity to pressure feedback caused by deformation difference is solved, the sudden change of pressure in the transition area of ​​the pressure chamber 40 is reduced, the sudden change of pressure between different partitions on the wafer 20 is slowed down, the pressure control of CMP in the junction area of ​​different pressure chambers 40 is effectively improved, and the sudden change of grinding rate of the wafer 20 at the connection of different partitions is slowed down, which is conducive to improving the flatness of the connection of different partitions of the wafer 20.

[0063] Regarding the height of the diaphragm 44, it may be related to the total height of the first side chamber wall. Figure 1 and Figure 3 In some embodiments, the height of the diaphragm 44 accounts for one third to two thirds of the total height of the first side cavity wall. Figure 3 , the height of the diaphragm 44 is Q1, and the total height of the first side cavity wall is Q2, then the height Q1 of the diaphragm 44 is one third to two thirds of the total height Q2 of the first side cavity wall.

[0064] The above embodiment has the following beneficial effects: if the height of the diaphragm 44 accounts for more than two-thirds of the total height of the first side cavity wall, when there is a pressure difference between two adjacent pressure chambers 40, the deformation amount of the diaphragm 44 toward the side with lower pressure will be larger, thereby significantly reducing the pressure difference between the two pressure chambers 40, which is not conducive to independent and obvious adjustment of the pressure applied to different partitions of the wafer 20; if the height of the diaphragm 44 accounts for less than one-third of the total height of the first side cavity wall, when there is a pressure difference between two adjacent pressure chambers 40, the deformation amount of the diaphragm 44 toward the side with lower pressure is almost small, and the increase in the area of ​​the transition area on the partitions of the wafer 20 corresponding to the two pressure chambers 40 is very small, and the effect of slowing down the sudden change of the grinding rate at the connection between different partitions of the wafer 20 is small, which is not conducive to improving the flatness of the connection between different partitions of the wafer 20. By controlling the height of the diaphragm 44 to one-third to two-thirds of the total height of the first side cavity wall, it is not only conducive to independent and obvious adjustment of the pressure applied to different partitions of the wafer 20, but also conducive to improving the flatness of the connection between different partitions of the wafer 20.

[0065] In some embodiments, reference Figure 1 and Figure 3The second side cavity wall includes: a first annular baffle 33 and a second annular baffle 34 formed by extending from the support plate 50 to the second surface in the direction of the adsorption membrane 10; wherein, the size of the first annular baffle 33 is larger than that of the second annular baffle 34, and the first annular baffle 33 and the second annular baffle 34 are concentrically arranged; the first annular baffle 33 and the second annular baffle 34 are both sealed and connected to the second surface of the adsorption membrane 10; and a portion of the first side cavity wall of the pressure chamber 40 adjacent to the second annular baffle 34 is formed by the second annular baffle 34.

[0066] The above embodiment has the following beneficial effects: by adopting a rigid first annular baffle 33 and a second annular baffle 34 to form the second side cavity wall of the adsorption chamber 30, when the adsorption chamber 30 is in a negative pressure state and the adjacent pressure chamber 40 is in a positive pressure state, the second annular baffle 34 will not deform or the deformation amount will be extremely small, so that the adsorption chamber 30 will not interfere with the normal pressure regulation function of the adjacent pressure chamber 40; and the first annular baffle 33 will not deform or the deformation amount will be extremely small, so as not to interfere with the normal operation of other structures in the grinding head.

[0067] In some embodiments, reference Figure 1 and Figure 3 , the diaphragm 44 is detachably sealed to the partition plate 43 ; and the first annular partition plate 33 and the second annular partition plate 34 are detachably sealed to the second surface of the adsorption membrane 10 .

[0068] The above embodiment has the following beneficial effects: the diaphragm 44 and the partition plate 43 are detachably sealed together, and the two annular partition plates 43 and the second surface of the adsorption membrane 10 are detachably sealed together, thereby facilitating replacement of the adsorption membrane 10 .

[0069] The detachable sealed connection can be realized in a variety of ways, such as, but not limited to, gluing, snapping, etc.

[0070] In some embodiments, reference Figure 1 and Figure 3 , the area of ​​the first bottom cavity wall 41 does not exceed a preset value. The preset value may be, for example but not limited to, 1 square centimeter, 1.5 square centimeters, or the like.

[0071] The above-mentioned embodiment has the following beneficial effects: by controlling the area of ​​the first bottom cavity wall 41 not to exceed the preset value, the area of ​​the pressure adjustment zone of a single pressure chamber 40 is made very small, and the area of ​​the partition relative to the position of each pressure chamber 40 on the wafer 20 is reduced, so that more pressure chambers 40 can be set, so that the pressure of different areas of the wafer 20 can be finely adjusted, which is beneficial to narrowing the difference in grinding rate between adjacent different partitions, greatly reducing the deformation at the junction of each partition, reducing the sudden change of pressure in the transition area, and effectively improving the pressure control of CMP in the junction area of ​​different pressure chambers 40, which is beneficial to improving the flatness of the ground wafer 20.

[0072] There are many ways to form the multiple pressure chambers 40. That is, as long as some of the pressure chambers 40 are distributed along the circumference of the wafer 20 or some of the pressure chambers 40 are distributed along the radial direction of the wafer 20, they are all within the protection scope of the embodiments of the present application.

[0073] In some embodiments, reference Figure 1 , Figure 2 , Figure 4~Figure 8 The multiple pressure chambers 40 include: at least two fan-shaped chambers that enclose a circular area; and at least two fan-shaped annular chambers that enclose at least one annular area; and the circular area and all the annular areas are concentrically arranged.

[0074] Specifically, the method of enclosing at least two fan-shaped annular chambers to form at least one annular area can be adopted in a variety of ways. For example, the number of enclosed annular areas can be 4, 5, 6, etc., and each annular area is formed by enclosing at least two fan-shaped annular chambers. Thus, based on the circumferential and radial directions of the wafer 20, the pressure chamber 40 is divided into several independent pressure adjustment areas of fan-shaped chambers / fan-shaped chambers. Each independent pressure chamber 40 can be connected to an external pressure supply device through a connecting pipe 60 on the support plate 50. The pressure supply device can be, for example, but not limited to, air pressure, oil pressure, etc. It should be noted that the number of pressure chambers 40, the angle and radius of the fan-shaped chamber or the fan-shaped chamber can be any value without restriction.

[0075] The above-mentioned embodiment has the following beneficial effects: by adopting a circular area enclosed by at least two fan-shaped chambers, and at least two fan-shaped annular chambers enclosed by at least one annular area, the wafer 20 is partitioned according to the radius range and angle range, thereby providing more controllable pressure chambers 40; based on the angle partitioning method, during the pressure control process, independent pressures can be given to the pressure chambers 40 at different angles at the same radius, thereby improving the flatness of the same radius area of ​​the wafer 20.

[0076] For example, the wafer 20 can be divided into a circular area and four annular areas every 3 cm in the radial direction, the angle of the fan-shaped chamber or the fan-annular chamber is 60°, a circular area is divided into 6 fan-shaped chambers, and an annular area is divided into 6 fan-annular chambers. Thus, a total of 30 independent pressure chambers 40 are formed. The 30 independent pressure chambers 40 are connected to the pressure supply device through the connecting pipe 60, and the control device performs independent air pressure control on each pressure chamber 40 connected to the connecting pipe 60.

[0077] The pressure in each pressure chamber 40 is proportional to the amount of grinding required for each partition on the wafer 20. For a partition area on the wafer 20 that requires a higher amount of grinding, the pressure of the pressure chamber 40 corresponding to the partition needs to be increased to provide a greater pressure to the partition and increase the grinding rate of the partition. For a partition area on the wafer 20 that requires a lower amount of grinding, the pressure of the pressure chamber 40 corresponding to the partition needs to be reduced to provide a smaller pressure to the partition and reduce the grinding rate of the partition. Since the pressure partitioning method is based on both radial distribution and circumferential distribution, the problem of thickness deviation of the wafer 20 can be solved.

[0078] In addition, the present application also provides a control method for the adsorption device based on any of the above-mentioned grinding heads, referring to Figure 1 to Figure 8 ,as well as Fig.10 , the control method comprises:

[0079] After the wafer 20 to be ground is adsorbed onto the grinding head by the adsorption chamber 30, a target grinding amount of the area on the wafer 20 to be ground corresponding to each pressure chamber 40 is obtained;

[0080] Based on the target grinding amount, the plurality of pressure chambers 40 are divided into at least two adjustment groups;

[0081] Determining a target pressure for each adjustment group based on a target grinding amount corresponding to each adjustment group;

[0082] Based on the target pressure of each regulating group, the pressure supply device is controlled to supply pressure to each pressure chamber 40 .

[0083] The above embodiment has the following beneficial effects: some of the multiple pressure chambers 40 on the grinding head are arranged along the circumference of the wafer 20, and some are arranged along the radial direction of the wafer 20, so that the grinding rates of different angle areas of the same radius area on the wafer 20 can be adjusted separately, which is beneficial to improve the flatness of the same radius area of ​​the wafer 20. And by obtaining the target grinding amount of the area on the wafer 20 to be ground that is opposite to each pressure chamber 40, and dividing the multiple pressure chambers 40 into at least two adjustment groups based on the target grinding amount, and then determining the target pressure of each adjustment group based on the target grinding amount corresponding to each adjustment group. By applying the same target pressure to the adjustment groups corresponding to the areas with similar or identical target grinding amounts, the grinding rates of the areas corresponding to the same adjustment group on the wafer 20 can be made the same, which is beneficial to the final grinding degree of the areas with similar or identical target grinding amounts being similar or identical, and is beneficial to improving the flattening treatment effect of the wafer 20. The above steps are described in detail below in conjunction with the accompanying drawings.

[0084] First, refer to Fig.10 After the wafer 20 to be ground is adsorbed onto the grinding head, a target grinding amount of an area on the wafer 20 to be ground corresponding to the position of each pressure adjustment zone is obtained.

[0085] There are many ways to adsorb the wafer 20 to be polished onto the polishing head. For example, an adsorption chamber 30 is provided on the polishing head, and the wafer 20 to be polished is adsorbed onto the polishing head through the adsorption chamber 30 .

[0086] There are many ways to obtain the target grinding amount of the area on the to-be-grinded wafer 20 that is opposite to each pressure adjustment zone. Specifically, the target grinding amount of the partitions on the wafer 20 that are opposite to each pressure adjustment zone can be obtained by analyzing the thickness of different pressure adjustment zones before and after grinding. Some of the methods are described as follows.

[0087] Exemplary, reference Fig.11 , obtaining a target grinding amount of an area on the to-be-grinded wafer 20 that is opposite to each pressure adjustment zone may include:

[0088] Acquire current thickness information of an area on the wafer 20 to be ground that is opposite to the position of each pressure adjustment zone;

[0089] Obtaining target thickness information of an area on the to-be-polished wafer 20 that is opposite to the position of each pressure adjustment zone;

[0090] Based on the current thickness information and the target thickness information, a target grinding amount of a region on the to-be-grinded wafer 20 opposite to the position of each pressure adjustment zone is determined.

[0091] The above-mentioned embodiment has the following beneficial effects: by determining the target grinding amount of the area opposite to the position of each pressure adjustment zone based on the current thickness information and target thickness information of the area opposite to the position of each pressure adjustment zone on the wafer 20 to be ground, it is beneficial to determine differentiated target grinding amounts according to the differences in current thickness information of different wafers 20, thereby facilitating improving the flattening processing effect on the wafer 20.

[0092] Next, refer to Fig.10 Based on the target grinding amount, the multiple pressure adjustment zones are divided into at least two adjustment groups. The specific division method can be adopted in many ways, and some methods are introduced as examples below.

[0093] Exemplary, reference Fig.12 , based on the target grinding amount, the plurality of pressure adjustment zones are divided into at least two adjustment groups, which may include:

[0094] Obtaining the maximum and minimum values ​​of all target grinding amounts, and calculating the difference between the maximum and minimum values;

[0095] Based on the difference, the total number of adjustment groups is determined;

[0096] Based on the difference and the total number of groups, the grinding amount range of each adjustment group is determined;

[0097] The plurality of pressure adjustment zones are divided into at least two adjustment groups based on a target grinding amount and a grinding amount range of each adjustment group.

[0098] The above-mentioned embodiment has the following beneficial effects: by determining the maximum and minimum values ​​of the target grinding amounts of all areas of the wafer 20 to be ground, and determining the total number of adjustment groups based thereon, a larger total number of groups can be determined when the difference is larger, and a smaller total number of groups can be determined when the difference is smaller, so that the total number of adjustment groups changes dynamically, which is conducive to balancing strategy control between simplifying the adjustment difficulty and improving the flattening processing effect on the wafer 20.

[0099] Next, refer to Fig.10 , based on the target grinding amount corresponding to each adjustment group, determine the target pressure of each adjustment group. The specific idea is: for the partition with higher grinding amount on the wafer 20 corresponding to the pressure adjustment zone of the adjustment group, the target pressure of the adjustment group needs to be increased to increase the grinding rate of the partition of the wafer 20 corresponding to the pressure adjustment zone in the adjustment group. For the partition with lower grinding amount on the wafer 20 corresponding to the pressure adjustment zone of the adjustment group, the target pressure of the adjustment group needs to be reduced to reduce the grinding rate of the partition of the wafer 20 corresponding to the pressure adjustment zone in the adjustment group.

[0100] There are many ways to determine the target pressure of each adjustment group, some of which are introduced as examples below.

[0101] Exemplarily, determining the target pressure of each adjustment group based on the target grinding amount corresponding to each adjustment group may include:

[0102] Calculate the average grinding amount of the target grinding amount corresponding to all the pressure adjustment zones in each adjustment group;

[0103] Based on the average grinding amount of each pressure adjustment group, the target pressure of each adjustment group is determined.

[0104] The above-mentioned embodiment has the following beneficial effects: by calculating the average grinding amount of the target grinding amount corresponding to all the pressure adjustment zones in each adjustment group, and determining the target pressure of each adjustment group based on the average grinding amount of the adjustment group, a more accurate target pressure can be determined for each adjustment group, which is conducive to the actual grinding amount of the area on the wafer 20 corresponding to the position of each pressure adjustment zone being close to or equal to the target grinding amount.

[0105] For example, the number of adjustment groups is As an example, the pressure adjustment areas with similar target grinding amounts are divided into one adjustment group, which is divided into Then the mean of the target grinding amount of the partitions corresponding to each pressure adjustment group in different adjustment groups can be calculated using the following formula:

[0106]

[0107] in, is the number of pressure regulation zones in the kth regulation group, is the target grinding amount of the m pressure adjustment zones in the kth adjustment group, is the mean grinding amount of the target grinding amount of the kth adjustment group.

[0108] There are many ways to determine the target pressure of each adjustment group based on the average grinding amount of each adjustment group, some of which are exemplified below.

[0109] Exemplary, reference Fig.13 , based on the average grinding amount of each adjustment group, determining the target pressure of each adjustment group may include:

[0110] Obtain the pressure-grinding rate correspondence of the grinding head in the current state;

[0111] Obtaining a target grinding time for the wafer 20 to be ground;

[0112] Determining a target grinding rate for each adjustment group based on the average grinding amount and the target grinding time for each adjustment group;

[0113] Based on the target grinding rate of each adjustment group and the pressure-grinding rate correspondence, the target pressure of each adjustment group is determined.

[0114] The above embodiment has the following beneficial effects: by calculating the target grinding rate of each adjustment group based on the average grinding amount and target grinding time of each adjustment group; and calculating the target pressure of each adjustment group based on the pressure-grinding rate correspondence under the current state of the grinding head; thus, when the state of the grinding head changes, the corresponding pressure-grinding rate correspondence will also change, so that the target pressure of each adjustment group can be determined according to the pressure-grinding rate correspondence under the latest state, so as to improve the accuracy of the determined target pressure.

[0115] There are many ways to obtain the pressure-grinding rate correspondence of the grinding head in the current state, and some of the ways are introduced as examples below.

[0116] Exemplarily, obtaining the pressure-grinding rate correspondence relationship under the current state of the grinding head may include:

[0117] Based on the current state information of the grinding head, determining the pressure-grinding rate correspondence relationship under the current state of the grinding head;

[0118] The current status information of the polishing head includes at least part of the following information: the pattern and roughness of the polishing pad, the pH value of the polishing liquid, the reaction rate between the polishing liquid and the wafer 20 to be polished, and the usage time of the polishing pad.

[0119] The above-mentioned embodiment has the following beneficial effects: by determining the pressure-grinding rate correspondence under the current state of the grinding head based on the current state information of the grinding head, when part or all of the information such as the pattern form and roughness of the grinding pad, the pH value of the grinding liquid, the reaction rate between the grinding liquid and the wafer 20 to be ground, and the used time of the grinding pad changes, the pressure-grinding rate correspondence also changes accordingly, so that the target pressure of each adjustment group can be determined based on the latest pressure-grinding rate correspondence to improve the accuracy of the determined target pressure.

[0120] It should be noted that the pressure-grinding rate correspondence relationship under the current state of the grinding head can be expressed in various forms, for example, it can be expressed as a functional relationship or in a table form.

[0121] The following is an exemplary method for determining the pressure-grinding rate correspondence of the grinding head in the current state.

[0122] Exemplarily, the grinding state coefficient of the grinding head can be determined according to the current state information of the grinding head; then, the pressure-grinding rate correspondence under the current state of the grinding head can be determined according to the grinding state coefficient of the grinding head.

[0123] For example, the pressure-grinding rate correspondence relationship under the current state of the grinding head can be the following functional relationship:

[0124]

[0125] in, represents pressure, V represents grinding rate, Indicates the grinding state coefficient.

[0126] The larger the grinding state coefficient is, the better the current state of the grinding head is, and the greater the grinding rate is at the same pressure. When determining the target pressure based on the target grinding rate and the pressure-grinding rate correspondence, under the same target grinding rate, the larger the grinding state coefficient is, the smaller the determined target pressure is.

[0127] The smaller the grinding state coefficient is, the worse the current state of the grinding head is, and the smaller the grinding rate is at the same pressure. When determining the target pressure based on the target grinding rate and the pressure-grinding rate correspondence, the smaller the grinding state coefficient is, the greater the target pressure is determined under the same target grinding rate.

[0128] When determining the grinding state coefficient β of the grinding head according to the current state information of the grinding head, various methods may be used. One method is exemplarily introduced as follows.

[0129] The grinding state coefficient β of the grinding head can be determined based on at least part of the information including the pattern and roughness of the grinding pad, the pH value of the grinding liquid, the reaction rate between the grinding liquid and the wafer 20 to be ground, and the usage time of the grinding pad.

[0130] For example, the more complex the pattern of the grooves of the polishing pad, the larger the corresponding polishing state coefficient β, that is, the two are positively correlated;

[0131] For example, the rougher the polishing pad, the larger the corresponding polishing state coefficient β, that is, the two are positively correlated;

[0132] For example, the time the polishing pad has been used affects the depth of the grooves on the polishing pad. When the grooves on the polishing pad are gradually smoothed as the use time increases, the surface of the polishing pad gradually becomes smoother, and the corresponding polishing state coefficient β becomes smaller. That is, the time the polishing pad has been used is negatively correlated with the polishing state coefficient β.

[0133] For example, the pH of the polishing liquid will affect the chemical reaction rate between the polishing liquid and the wafer 20. For different wafers 20, there is always a corresponding optimal pH so that the chemical reaction rate between the polishing liquid and the wafer 20 reaches the optimal reaction rate, which is beneficial to improving the polishing rate. The closer the pH of the polishing liquid is to the optimal pH, the higher the efficiency of the chemical reaction rate between the polishing liquid and the wafer 20, the faster the corrosion rate of the polishing liquid on the wafer 20, the more beneficial to improving the polishing rate, and the larger the polishing state coefficient β. The further the pH of the polishing liquid deviates from the optimal pH, the lower the efficiency of the chemical reaction rate between the polishing liquid and the wafer 20, or even no chemical reaction occurs or other side chemical reactions occur, the slower the corrosion rate of the polishing liquid on the wafer 20, the more unfavorable to improving the polishing rate, and the smaller the polishing state coefficient β.

[0134] For example, the faster the reaction rate between the polishing liquid and the wafer 20 to be polished, the more conducive it is to improving the polishing rate, and the larger the polishing state coefficient β is. That is, the reaction rate between the polishing liquid and the wafer 20 to be polished is positively correlated with the polishing state coefficient β.

[0135] A score value can be assigned to each state information in the current state information of the grinding head, and corresponding weight values ​​can be assigned to different state information according to the degree of contribution to the grinding rate. Then, the grinding state coefficient β is calculated using a weighted average algorithm based on the score values ​​of these state information.

[0136] In other embodiments, other methods may be used to determine the target pressure of each adjustment group based on the average grinding amount of each adjustment group.

[0137] For example, based on the average grinding amount of each adjustment group, the target pressure of each adjustment group can be determined in the following manner:

[0138] Obtaining a preset grinding amount mean-pressure correspondence relationship;

[0139] Based on the average grinding amount of each adjustment group and the corresponding relationship between the average grinding amount and the pressure, the target pressure of each adjustment group is determined.

[0140] The above embodiment has the following beneficial effects: the target pressure of each adjustment group is determined by the preset grinding amount mean value-pressure correspondence relationship, thereby simplifying the calculation amount of determining the target pressure of each adjustment group.

[0141] There are many ways to obtain the preset grinding amount mean-pressure correspondence relationship, some of which are exemplified below.

[0142] Exemplarily, obtaining a preset grinding amount mean-pressure correspondence relationship may include:

[0143] The following grinding amount mean-pressure correspondence model is established:

[0144]

[0145] in, Indicates pressure, Indicates the average grinding amount, represents the proportionality coefficient;

[0146] Determine the proportionality coefficient based on the current state information of the grinding head; wherein the current state information of the grinding head includes at least part of the following information: the pattern form and roughness of the grinding pad, the pH value of the grinding liquid, the reaction rate between the grinding liquid and the wafer 20 to be ground, and the used time of the grinding pad;

[0147] Based on the proportionality coefficient and the grinding amount mean value-pressure correspondence model, the grinding amount mean value-pressure correspondence relationship is determined.

[0148] The above embodiment has the following beneficial effects: by determining the proportional coefficient based on the current state information of the grinding head, when at least part of the current state information of the grinding head changes, the proportional coefficient also changes accordingly, so that the determined grinding amount mean-pressure correspondence is dynamically adjusted, which is conducive to determining a more accurate target pressure.

[0149] For example, the number of adjustment groups is For example,

[0150]

[0151] in is the proportionality coefficient, is the target pressure of the kth adjustment group, is the mean grinding amount of the target grinding amount of the kth adjustment group.

[0152] In the process of determining the mean grinding amount-pressure correspondence relationship based on the proportional coefficient and the mean grinding amount-pressure correspondence relationship model, the proportional coefficient determined based on the current state information of the grinding head can be substituted into the mean grinding amount-pressure correspondence relationship model to obtain a function type mean grinding amount-pressure correspondence relationship.

[0153] In the subsequent process of determining the target pressure based on the average grinding amount and the corresponding relationship between the average grinding amount and the pressure, the following corresponding relationship is obtained.

[0154] Scale factor The larger the value is, the greater the target pressure will be when the grinding amount is the same. Correspondingly, when the pressure is the same, the proportional coefficient The larger it is, the smaller the average grinding amount is.

[0155] Scale factor The smaller the value, the smaller the target pressure is when the grinding amount is the same. Correspondingly, when the pressure is the same, the proportionality coefficient is The smaller it is, the larger the average grinding amount is.

[0156] From the above, it can be seen that the proportionality coefficient The larger the ratio is, the slower the grinding speed of the grinding head will be under the same pressure, so the average grinding amount can be smaller; the proportional coefficient The smaller it is, the faster the grinding speed of the grinding head will be under the same pressure, so the average grinding amount can be greater. It is negatively correlated with the grinding rate of the grinding head.

[0157] When determining the proportionality coefficient based on the current state information of the grinding head, various methods may be used, some of which are exemplarily introduced below.

[0158] Exemplarily, the grinding state coefficient of the grinding head may be determined according to the current state information of the grinding head; then, the inverse of the grinding state coefficient of the grinding head is used as the proportional coefficient.

[0159] For example, the grinding state coefficient of the grinding head can be , proportionality coefficient Can be equal to 1 / .

[0160] Grinding state coefficient of grinding head For the determination method, please refer to the description of the corresponding part above, which will not be repeated here.

[0161] There are many ways to set up multiple pressure adjustment zones, some of which are introduced as examples below.

[0162] Exemplarily, the plurality of pressure regulating zones include:

[0163] At least two sector-shaped pressure regulating areas enclosing a circular area; and,

[0164] At least two sector-annular pressure regulating zones enclose at least one annular area; wherein the circular area and all the annular areas are concentrically arranged.

[0165] Specifically, the method of enclosing at least two fan-shaped pressure regulation zones into at least one annular area can be adopted in a variety of ways. For example, the number of enclosed annular areas can be 4, 5, 6, etc., and each annular area is formed by enclosing at least two fan-shaped pressure regulation zones. Thus, based on the circumferential and radial directions of the wafer 20, the pressure regulation area is divided into several independent pressure regulation areas of fan-shaped pressure regulation areas / fan-shaped pressure regulation areas. Each independent pressure regulation area can be connected to an external pressure supply device through a connecting pipe 60 on the support plate 50. The pressure supply device can be such as but not limited to air pressure, oil pressure and the like. It should be noted that the number of pressure regulation zones, the angle and radius of the fan-shaped pressure regulation zone or the fan-shaped pressure regulation zone can be any value without restriction.

[0166] The above-mentioned embodiment has the following beneficial effects: by adopting a circular area enclosed by at least two fan-shaped pressure adjustment zones, and at least two fan-shaped annular pressure adjustment zones enclosed by at least one annular area, the wafer 20 is partitioned according to the radius range and angle range, thereby providing more controllable pressure adjustment areas; based on the angle partitioning method, during the pressure control process, independent pressures can be given to pressure adjustment zones at different angles at the same radius, thereby improving the flatness of the same radius area of ​​the wafer 20.

[0167] For example, the wafer 20 can be divided into a circular area and four annular areas every 3 cm in the radial direction, the angle of the fan-shaped pressure adjustment area or the fan-shaped annular pressure adjustment area is 60°, a circular area is divided into 6 fan-shaped pressure adjustment areas, and an annular area is divided into 6 fan-shaped pressure adjustment areas. Thus, a total of 30 independent pressure adjustment areas are formed. The 30 independent pressure adjustment areas are connected to the pressure supply device through the connecting pipe 60, and the control device performs independent air pressure control on each pressure chamber 40 connected to the connecting pipe 60.

[0168] Of course, the division along the radial direction of the wafer 20 is not limited to the five radial regions shown above, and can be any value. Of course, the division along the circumferential direction of the wafer 20 is not limited to the six sectors or sector rings shown above, and can be any value.

[0169] Each pressure regulating zone can independently control the pressure to independently apply pressure to the corresponding zone of the wafer 20. Each pressure regulating zone in the same regulating group is controlled uniformly.

[0170] Some exemplary methods are introduced below.

[0171] by Figure 5For example, when the partition on the wafer 20 corresponding to the pressure adjustment zone A3 requires a larger amount of grinding, while the partition on the wafer 20 corresponding to the pressure adjustment zone D3 requires a smaller amount of grinding, the existing pressure control method based on the radius can only increase or decrease the pressure of the entire region 3, which often results in the partition corresponding to the pressure adjustment zone A3 being thicker as a whole after grinding, while the partition corresponding to the pressure adjustment zone D3 being thinner as a whole, resulting in the problem of thickness deviation of the wafer 20. The present invention can divide A3 and D3 into different adjustment groups, pressurize A3, and decompress D3, and finally achieve flattening of the entire region 3.

[0172] Continue with Figure 5 For example, when the wafer 20 partition corresponding to pressure adjustment zone A requires more grinding than the wafer 20 partition corresponding to pressure adjustment zones B, C, E, and F, and the wafer 20 partition corresponding to pressure adjustment zone D requires less grinding than the wafer 20 partition corresponding to pressure adjustment zones B, C, E, and F, the existing pressure control method based on radius cannot handle it. However, the present invention can divide the pressure adjustment zones A1-A5 into one adjustment group, and divide the pressure adjustment zones D1-D5 into another adjustment group, uniformly pressurize the pressure adjustment zones A1-A5, and uniformly depressurize the pressure adjustment zones D1-D5, and finally achieve the flattening of the entire wafer 20.

[0173] Continue with Figure 5 For example, when the amount of grinding required for the wafer 20 partition corresponding to the pressure adjustment zones A2, A3, B2, and B3 is greater than the average value of the entire wafer 20, and the amount of grinding required for the wafer 20 partition corresponding to the pressure adjustment zones D3, D4, E3, and E4 is less than the average value of the entire wafer 20, the existing pressure control method based on the radius cannot handle it. However, the present invention can divide the pressure adjustment zones A2, A3, B2, and B3 into the same adjustment group and pressurize the entire group; divide the pressure adjustment zones D3, D4, E3, and E4 into another adjustment group and depressurize the entire group, and finally achieve the flattening of the entire wafer 20.

[0174] It can be seen that the above embodiment of the present application effectively improves the process accuracy, and can add a means of controlling the pressure according to the angle on the basis of taking into account the pressure control of each radius area of ​​the traditional CMP, solving the problem that the traditional CMP cannot control the thickness of each point in the same radius partition, further improving the grinding flatness, and ensuring the yield and reliability of the grinding product. The pressure control means of the group partition of the present design is adjustable and can be applied to the grinding requirements of different situations.

[0175] The existing CMP only regulates the pressure based on radius zones, and the regulation accuracy is insufficient and cannot meet production requirements. The method provided by the above embodiment of the present invention provides more regulation areas. The existing CMP has consistent pressure within the same radius area, making it difficult to grind wafers 20 of different thicknesses at the same radius flat. The above embodiment of the present invention can give independent pressure to areas at different angles at the same radius based on the top-down polar coordinate angle, thereby improving the flatness of the area with the same radius.

[0176] In addition, an embodiment of the present application also provides a grinding head, which includes: multiple pressure adjustment zones and a control device, each pressure adjustment zone is used to independently adjust the pressure of a relative area on the wafer 20; a control device is used to adopt any of the above-mentioned control methods to control the pressure supply device to supply pressure to each pressure adjustment zone.

[0177] The above embodiment has the following beneficial effects: some of the multiple pressure adjustment zones on the grinding head are arranged along the circumference of the wafer 20, and some are arranged along the radial direction of the wafer 20, so that the grinding rates of different angle areas of the same radius area on the wafer 20 can be adjusted separately, which is beneficial to improving the flatness of the same radius area of ​​the wafer 20. And by obtaining the target grinding amount of the area on the wafer 20 to be ground that is opposite to the position of each pressure adjustment zone, and dividing the multiple pressure adjustment zones into at least two adjustment groups based on the target grinding amount, and then determining the target pressure of each adjustment group based on the target grinding amount corresponding to each adjustment group. By applying the same target pressure to the adjustment groups corresponding to the areas with similar or identical target grinding amounts, the grinding rates of the areas corresponding to the same adjustment group on the wafer 20 can be made the same, which is beneficial to the final grinding degree of the areas with similar or identical target grinding amounts being similar or identical, and is beneficial to improving the flattening effect of the wafer 20.

[0178] In addition, the present application also provides a chemical mechanical polishing device, referring to Figure 1 to Figure 8 The chemical mechanical polishing equipment includes: a polishing pad, a polishing liquid supplier, a pressure supply device and a polishing head; wherein the polishing liquid supplier is used to spray the polishing liquid onto the polishing pad; the polishing head includes any one of the above-mentioned adsorption devices of the polishing head, and multiple pressure chambers 40 are respectively connected to the external pressure supply device.

[0179] The grinding pad assists in grinding the wafer 20 through physical action. The grinding liquid assists in grinding the wafer 20 through chemical action. The chemical mechanical grinding equipment may also include a grinding pad dresser, which is used to dress the grinding pad to maintain its grinding ability. The grinding pad can be set on a grinding disk, which is used to carry the above-mentioned overall equipment. Of course, the chemical mechanical grinding equipment may also include a control device, which is used to control the movement of each device in the chemical mechanical grinding equipment and the pressure supply of the pressure supply device. Of course, in addition to the above-mentioned devices, the chemical mechanical grinding equipment may also include any other auxiliary components.

[0180] The present application has been described through the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of example and illustration, and are not intended to limit the present application to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present application is not limited to the above-mentioned embodiments, and more variations and modifications can be made according to the teachings of the present application, and these variations and modifications all fall within the scope of protection claimed by the present application. The scope of protection of the present application is defined by the attached claims and their equivalents.

Claims

1. A grinding head adsorption device, characterized in that: include: An adsorption film made of an elastic material, the adsorption film having a first surface and a second surface opposite to each other, the first surface being used to contact a wafer; wherein the wafer comprises a central area and an edge area surrounding the central area; an adsorption chamber disposed on the second surface, the adsorption chamber being used for adsorbing the edge region; A plurality of pressure chambers are provided on the second surface; the plurality of pressure chambers are used to be connected to external pressure supply devices respectively, so that each of the pressure chambers can adjust the pressure therein through an independent pressure supply device, thereby adjusting the pressure applied to the area on the central area opposite to the position of the pressure chamber; Part of the pressure chambers are arranged along the circumference of the wafer, and part of the pressure chambers are arranged along the radial direction of the wafer; The adsorption device further comprises: a support plate spaced apart from the second surface of the adsorption membrane, wherein the adsorption chamber and the pressure chamber are disposed between the adsorption membrane and the support plate; The pressure chamber comprises a first bottom cavity wall formed by the adsorption film, a first top cavity wall formed by the support plate, and a first side cavity wall connected between the first bottom cavity wall and the first top cavity wall; wherein the first side cavity wall comprises a partition formed by the support plate extending toward the adsorption film, and a diaphragm formed by the adsorption film extending toward the support plate, wherein the partition is sealedly connected to the diaphragm; The adsorption chamber comprises a second bottom cavity wall formed by the adsorption membrane, a second top cavity wall formed by the support plate, and a second side cavity wall connected between the second bottom cavity wall and the second top cavity wall; the second side cavity wall comprises a first annular baffle and a second annular baffle formed by the support plate extending toward the adsorption membrane to the second surface; wherein the size of the first annular baffle is larger than that of the second annular baffle, and the first annular baffle is concentrically arranged with the second annular baffle; The first annular partition plate and the second annular partition plate are both sealed and connected to the second surface of the adsorption membrane, and a portion of the first side chamber wall of the pressure chamber adjacent to the second annular partition plate is formed by the second annular partition plate.

2. The adsorption device according to claim 1, characterized in that: The height of the diaphragm accounts for one third to two thirds of the total height of the first side cavity wall.

3. The adsorption device according to claim 1, characterized in that: a detachable sealed connection between the diaphragm and the partition; Furthermore, the first annular partition plate, the second annular partition plate and the second surface of the adsorption membrane are detachably sealed and connected to each other.

4. The adsorption device according to claim 1, characterized in that: The area of ​​the first bottom cavity wall does not exceed a preset value.

5. The adsorption device according to any one of claims 1 to 4, characterized in that: The plurality of pressure chambers include: At least two sector-shaped chambers enclosing a circular area; and, At least two fan-shaped annular chambers enclose at least one annular area; and the circular area and all the annular areas are concentrically arranged.

6. A chemical mechanical polishing device, characterized in that: include: Abrasive pads; A grinding liquid supplier, used for spraying the grinding liquid onto the grinding pad; Pressure supply device; as well as, A grinding head, comprising the adsorption device of the grinding head as described in any one of claims 1 to 5, wherein the plurality of pressure chambers are respectively connected to an external pressure supply device.

7. A control method for an adsorption device of a grinding head according to any one of claims 1 to 5, characterized in that: include: After the wafer to be ground is adsorbed onto the grinding head through the adsorption chamber, a target grinding amount of a region on the wafer to be ground corresponding to the position of each pressure chamber is obtained; Based on the target grinding amount, the plurality of pressure chambers are divided into at least two adjustment groups; Determining a target pressure of each adjustment group based on the target grinding amount corresponding to each adjustment group; Based on the target pressure of each of the regulating groups, a pressure supply device is controlled to supply pressure to each of the pressure chambers.

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