Carrying head for wafer processing, chemical mechanical polishing apparatus and method

Abstract

The embodiment of the present application provides a kind of for wafer processing's bearing head, chemical mechanical polishing equipment and method, bearing head includes the main part of circular, its inside has first vent line and second vent line;First elastic film, between the surface of main part and it defines center cavity and multiple annular cavities, multiple annular cavities are concentric with center cavity, center cavity and multiple annular cavities are communicated with first vent line, to make the lower surface of first elastic film adsorb or release wafer, and at least one of multiple annular cavities is provided with multiple air holes towards the surface of wafer;Second elastic film, in the annular cavity with multiple air holes, second elastic film is communicated with second vent line, to block and open air hole.The embodiment of the present application provides a kind of bearing head, device and wafer polishing method, can stably adsorb wafer, and after wafer polishing operation is completed, make wafer and bearing head separate.

Description

Technical Field

[0001] This application relates to the field of wafer polishing technology, and more particularly to a carrier head, chemical mechanical polishing equipment and method for wafer processing. Background Technology

[0002] In semiconductor manufacturing, wafer polishing is one of the process steps. Most current wafer carriers suffer from problems such as unstable adsorption and complex operation, affecting polishing efficiency and quality. The carrier can adjust the pressure of the elastic membrane to achieve a series of wafer pick-up and drop actions. However, when the wafer is thin or in high-pressure (HDF) processes, the wafer pick-up and drop failure rate increases significantly. For example, in the polishing process of third-generation semiconductor SiC wafers, due to the high elastic modulus, high specific stiffness, and stable chemical properties of the SiC substrate, high pressure (7 psi) and long polishing time (15-30 min) are required. This causes a "sticking" phenomenon between the elastic membrane and the wafer, making it impossible to smoothly place the wafer using conventional pick-up and drop settings. Summary of the Invention

[0003] In view of this, embodiments of this application provide a carrier head, chemical mechanical polishing equipment and method for wafer processing, which can stably adsorb wafers and detach the wafers from the carrier head after the wafer polishing operation is completed.

[0004] According to a first aspect of this application, a carrier head for wafer processing is provided, comprising a circular main body having a first vent and a second vent inside; a first elastic membrane defining a central cavity and a plurality of annular cavities between itself and the surface of the main body, the plurality of annular cavities being concentric with the central cavity, the central cavity and the plurality of annular cavities being connected to the first vent, such that the lower surface of the first elastic membrane adsorbs or releases the wafer, and at least one of the plurality of annular cavities having a plurality of pores on its surface facing the wafer; and a second elastic membrane located within the annular cavity having the plurality of pores, the second elastic membrane being connected to the second vent to block and open the pores.

[0005] Optionally, the first elastic membrane includes an outer peripheral longitudinal wall, a first elastic bottom wall, a plurality of inner peripheral longitudinal walls, and a first top wall. The first top wall is connected to the lower surface of the main body. The first elastic bottom wall is connected to the lower surface of the main body through the outer peripheral longitudinal wall to form an internal cavity. The plurality of inner peripheral longitudinal walls are all concentrically arranged inside the outer peripheral longitudinal wall, and the diameters of the plurality of inner peripheral longitudinal walls are different, so as to divide the internal cavity into a central cavity and a plurality of annular cavities.

[0006] Optionally, the second elastic membrane includes a second elastic bottom wall, a pleated side wall, and a second top wall. The second top wall is connected to the lower surface of the main body. The second top wall and the second elastic bottom wall are connected by the pleated side wall to form an inflation chamber. The inflation chamber is connected to the second ventilation pipe.

[0007] Optionally, when the inflation chamber is inflated, the second elastic membrane expands, and the width of the second elastic bottom wall is the same as the width of the first elastic bottom wall.

[0008] Optionally, the second top wall of the second elastic membrane has the same width as the second elastic bottom wall.

[0009] Optionally, the width of the second top wall of the second elastic membrane is half the width of the first top wall, and the width of the second elastic bottom wall is two-thirds the width of the first elastic bottom wall.

[0010] Optionally, the second elastic membrane and the first elastic membrane satisfy the following relationship: b>5t1;

[0011] Where t1 is the thickness of the sidewall of the second elastic membrane; t2 is the thickness of the inner circumferential longitudinal wall; and b is the width of a single fold of the folded sidewall.

[0012] Optionally, the hardness of the second elastic membrane is less than that of the first elastic membrane, and the hardness of the second elastic membrane ranges from 37HA to 42HA.

[0013] According to a second aspect of this application, a wafer polishing method is provided, which is applicable to controlling the carrier head described in the first aspect embodiment above, comprising: inflating a second elastic membrane with a second venting conduit of the carrier head to cause the second elastic membrane to expand and seal the vent holes; moving the carrier head to a wafer pick-up position, wherein the first elastic bottom wall of the first elastic membrane is in contact with the wafer; the first venting conduit creating a negative pressure in the internal cavity to disengage the middle portion of the first elastic bottom wall from the wafer and adsorb the wafer; the carrier head moving the wafer to a polishing pad and lowering the height of the carrier head to make the wafer fit against the polishing pad; the second aspect of this application provides a wafer polishing method, which is applicable to controlling the carrier head described in the first aspect embodiment above, comprising: inflating a second elastic membrane with a second venting conduit of the carrier head to cause the second elastic membrane to expand and seal the vent holes; moving the carrier head to a wafer pick-up position, wherein the first elastic bottom wall of the first elastic membrane is in contact with the wafer; the second venting conduit creating a negative pressure in the internal cavity to cause the middle portion of the first elastic bottom wall to disengage from the wafer and adsorb the wafer; the second venting conduit moving the wafer to a polishing pad and lowering the height of the carrier head to make the wafer fit against the polishing pad; the second venting conduit moving the second elastic bottom wall to a polishing pad; the second venting conduit moving the second elastic bottom wall to a wafer pick-up position, wherein the second venting conduit moving the second elastic bottom wall is in contact with the wafer ... to a wafer pick-up position, wherein the second venting conduit moving the second elastic bottom wall to a A venting line creates positive pressure in the internal chamber, causing the first elastic bottom wall to contact the wafer surface and press the wafer against the polishing pad. Simultaneously, a second venting line inflates the second elastic membrane to seal the pores, and the polishing pad polishes the wafer surface. After polishing, the first venting line creates negative pressure in the internal chamber, causing the middle part of the first elastic bottom wall to detach from the wafer, adsorbing the wafer and moving it to the wafer placement location. The second venting line stops inflating, causing the second elastic membrane to contract and open the pores. The first venting line blows gas out through the pores, causing the wafer to detach from the first elastic bottom wall of the first elastic membrane.

[0014] According to a third aspect of this application, a chemical mechanical polishing apparatus is provided, including a support head, wherein the support head is the support head described in the first aspect of the above-described embodiment.

[0015] Optionally, the chemical mechanical polishing (CMP) equipment is characterized by further comprising: a controller for performing the following steps: inflating the second elastic membrane through the second venting conduit of the carrier head to cause the second elastic membrane to expand and seal the pores; controlling the carrier head to move to the wafer pick-up position, wherein the first elastic bottom wall of the first elastic membrane is in contact with the wafer; controlling the first venting conduit to create a negative pressure in the internal cavity to disengage the middle portion of the first elastic bottom wall from the wafer and adsorb the wafer; controlling the carrier head to move the wafer to the polishing pad and lowering the height of the carrier head to make the wafer fit with the polishing pad; controlling the first venting conduit to... A positive pressure is formed in the internal chamber, causing the first elastic bottom wall to contact the surface of the wafer and press the wafer against the polishing pad. Simultaneously, the second venting pipe inflates the second elastic membrane to seal the pores, and the polishing pad polishes the wafer surface. After polishing, the first venting pipe is controlled to create a negative pressure in the internal chamber, causing the middle part of the first elastic bottom wall to detach from the wafer, adsorbing the wafer and moving it to the wafer placement location. The second venting pipe is then stopped inflating, causing the second elastic membrane to contract and open the pores. The first venting pipe blows gas out through the pores, causing the wafer to detach from the first elastic bottom wall of the first elastic membrane.

[0016] According to a fourth aspect of this application, a computer storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the wafer grinding time determination method as described above.

[0017] According to a fifth aspect of this application, a computer program product is provided, including computer instructions that instruct a computing device to perform operations corresponding to the wafer grinding time determination method described above.

[0018] According to the carrier head provided in the first aspect of this application, the first venting conduit can provide positive and negative pressure gas to the central cavity and multiple annular cavities between the first elastic membranes, and the second venting conduit can provide positive and negative pressure gas to the interior of the second elastic membrane. The first elastic bottom wall of the annular cavity with the second elastic membrane has vent holes. This allows the second elastic membrane to expand and block the vent holes during wafer adsorption, ensuring stable wafer adsorption and preventing liquids (such as water or polishing fluid) and debris or particles generated during polishing from entering the annular cavity through the vent holes, thus preventing corrosion of the metal structure inside the carrier head. After polishing, gas can be blown out through the vent holes to detach the wafer from the first elastic bottom wall of the first elastic membrane. Furthermore, the overall structure is simple, requiring no additional equipment or structures, making it convenient and quick. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of 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 the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a structural side view of the bearing head according to the first aspect of this application;

[0021] Figure 2 This is a cross-sectional view along line AA of one embodiment of the bearing head according to the first aspect of this application;

[0022] Figure 3 for Figure 2 A magnified view of a section at point B in the middle;

[0023] Figure 4 This is a cross-sectional view along line AA of another embodiment of the carrier head according to the first aspect of this application;

[0024] Figure 5 for Figure 4 A magnified view of a section at point C;

[0025] Figure 6 This is a cross-sectional view along line AA of another embodiment of the carrier head according to the first aspect of this application;

[0026] Figure 7 for Figure 6 A magnified view of a section at point E in the middle;

[0027] Figure 8 A schematic diagram of a chemical mechanical polishing apparatus according to the second aspect of this application;

[0028] Figure 9 This is a flowchart of a wafer polishing method according to a third aspect of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] Chemical mechanical polishing equipment 1000;

[0031] Carrier head 100:

[0032] Main body 10;

[0033] First elastic membrane 20; outer peripheral longitudinal wall 201; first elastic bottom wall 202; inner peripheral longitudinal wall 203; first top wall 204;

[0034] Internal chamber 30; central cavity 301; annular cavity 302; vent 3021;

[0035] Second elastic membrane 40; second elastic bottom wall 401; pleated side wall 402; second top wall 403;

[0036] Inflatable chamber 50;

[0037] Polishing pad 200; Polishing disc 300; Dresser 400; Liquid supply unit 500;

[0038] Wafer W; Axis Ax. Detailed Implementation

[0039] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0040] As mentioned earlier, wafer polishing is one of the process steps in semiconductor manufacturing. Most current wafer carriers 100 suffer from problems such as unstable adsorption and complex operation, affecting polishing efficiency and quality. The wafer carrier 100 can achieve a series of actions for picking up and placing wafers W through the adjustment of elastic membrane pressure. However, when the wafer W is thin or used in high-pressure (HDF) processes, the failure rate of picking up and placing wafers W increases significantly. For example, in the polishing process of third-generation semiconductor SiC wafers W, due to the high elastic modulus, high specific stiffness, and stable chemical properties of the SiC substrate, high pressure (7 psi) and long polishing time (15-30 min) are required. This causes a "sticking" phenomenon between the elastic membrane and the wafer, making it impossible to smoothly place the wafer W using conventional pick-and-place settings.

[0041] Therefore, the carrier head 100 needs to be able to stably adsorb the wafer W, and also needs to be able to safely detach the wafer W from the carrier head 100 after the wafer W has been polished, so as to prevent the wafer W from being difficult to detach due to excessive pressure adsorbed by the carrier head 100, or from being damaged when detached.

[0042] Therefore, the first aspect of this application provides a carrier head 100, a chemical mechanical polishing apparatus 1000, and a method for wafer processing. The following description is in conjunction with the appended specification. Figures 1-7 The first aspect of this application describes in detail the carrier head 100 for wafer fabrication.

[0043] like Figure 1 The diagram shown is a schematic representation of the overall structure of the carrier head 100 for wafer fabrication according to the first aspect of this application. Figure 2As shown, the carrier head 100 for wafer processing according to the first aspect of this application includes a circular main body 10, a first elastic membrane 20, and a second elastic membrane 40. The main body 10 has a first venting channel and a second venting channel inside, the first venting channel being able to provide positive or negative pressure gas to the cavity formed between the first elastic membrane 20 and the main body 10.

[0044] The second vent pipe can provide positive or negative pressure gas to the cavity formed between the second elastic membrane 40 and the main body 10. The main body 10 has a disc-shaped structure in its top view, which facilitates its rotation.

[0045] like Figure 2 As shown, a central cavity 301 and a plurality of annular cavities 302 are defined between the surface of the first elastic membrane 20 and the main body 10. The central cavity 301 is the cavity corresponding to the central region of the main body 10 among the plurality of cavities formed between the first elastic membrane 20 and the main body 10. The annular cavities 302 are a plurality of annular cavities surrounding the central cavity 301, and all annular cavities 302 are concentric with the central cavity 301. The central cavity 301 and the plurality of annular cavities 302 are all connected to a first ventilation conduit, thereby allowing positive or negative pressure gas to be supplied through the first ventilation conduit, enabling the lower surface of the first elastic membrane 20 to adsorb or detach the wafer W. For example, when positive pressure gas is introduced, the first elastic membrane 20 can be filled with gas, thereby pressing the wafer W onto the polishing pad 200 during the polishing process, preventing the wafer W from slipping and ensuring uniform polishing of the wafer W. When connected to a negative pressure gas, the middle part of the first elastic membrane 20 is recessed, thereby adsorbing the wafer W and facilitating the handling of the wafer W.

[0046] like Figure 3 , Figure 5 and Figure 7 As shown, at least one of the multiple annular cavities 302 has multiple air holes 3021 on its surface facing the wafer W. Air can be blown through the air holes 3021 when it is necessary to loosen the wafer W from the lower surface of the first elastic film 20, thereby ensuring that the wafer W stably detaches from the first elastic film 20. This prevents the wafer W from failing to detach smoothly from the first elastic film 20 due to excessive pressing time or pressure during wafer W polishing, or from cracking due to uneven force during detachment.

[0047] like Figures 2-7As shown, the carrier head 100 also has a second elastic membrane 40, which is located within an annular cavity 302 having multiple vents 3021. The second elastic membrane 40 is connected to a second ventilation pipe to seal and open the vents 3021. Specifically, when the wafer W is polished, the first elastic membrane 20 is filled with positive pressure gas, causing it to expand. The second elastic membrane 40 is also supplied with positive pressure gas through the second ventilation pipe, thereby expanding and sealing the vents 3021, preventing the gas filled in the first elastic membrane 20 from leaking out and ensuring that the first elastic membrane 20 can stably press the wafer W. In addition, the second elastic membrane 40 sealing the vents 3021 can also prevent liquids (such as water or polishing fluid) generated during the wafer W polishing process, as well as debris or particles generated during the polishing process, from entering the annular cavity 302 through the vents 3021, thereby corroding the metal structure inside the carrier head 100.

[0048] Furthermore, by employing a structure of a first elastic membrane 20 and a second elastic membrane 40, the elastic membrane and wafer W are loosened through the expansion and contraction of multiple sets of elastic membranes, rather than requiring multiple adjustments to the elastic membrane pressure. This avoids the problem that the elasticity of the elastic membrane rapidly deteriorates with increasing polishing cycles, and that prolonged wafer placement time affects polishing efficiency and results in poor performance.

[0049] In this embodiment of the invention, the bottom wall width of the cross-section of the first elastic membrane 20 is denoted by D3, the bottom wall width of the cross-section of the second elastic membrane 40 is denoted by D2, and the top wall width of the cross-section of the second elastic membrane 40 is denoted by D1. Furthermore, D1 < D2 < D3. D1, D2, and D3 are all within... Figure 3 The symbols are shown in the figures and will not be labeled in other figures.

[0050] According to the carrier head 100 provided in this application embodiment, the first venting pipe can provide positive and negative pressure gas to the central cavity 301 and multiple annular cavities 302 between the first elastic membranes 20, and the second venting pipe can provide positive and negative pressure gas to the interior of the second elastic membrane 40. The first elastic bottom wall 202 of the annular cavity 302 with the second elastic membrane 40 has vent holes 3021. This allows the second elastic membrane 40 to expand and block the vent holes 3021 during wafer W adsorption, ensuring stable wafer W adsorption and preventing liquids (e.g., water or polishing fluid) and debris or particles generated during the wafer W polishing process from entering the annular cavity 302 through the vent holes 3021, thus preventing corrosion of the metal structure inside the carrier head 100. After polishing, gas can be blown out through the vent holes 3021 to detach the wafer W from the first elastic bottom wall 202 of the first elastic membrane 20. Furthermore, the overall structure is simple, requiring no additional equipment or structures, making it convenient and quick.

[0051] like Figure 2As shown, the first elastic membrane 20 includes an outer peripheral longitudinal wall 201, a first elastic bottom wall 202, a plurality of inner peripheral longitudinal walls 203 and a first top wall 204. The first top wall 204 is connected to the lower surface of the main body 10. The first elastic bottom wall 202 is connected to the lower surface of the main body 10 through the outer peripheral longitudinal wall 201, forming an internal cavity 30. The plurality of inner peripheral longitudinal walls 203 are all concentrically arranged inside the outer peripheral longitudinal wall 201, and the diameters of the plurality of inner peripheral longitudinal walls 203 are different, so as to divide the internal cavity 30 into a central cavity 301 and a plurality of annular cavities 302.

[0052] Specifically, an internal cavity 30 is formed between the lower surface of the main body 10 and the first elastic membrane 20. The first elastic membrane 20 is connected to the lower surface of the main body 10 via a first top wall 204. The outer peripheral wall of the first elastic membrane 20 is an outer peripheral longitudinal wall 201, forming an external longitudinal wall structure. The internal cavity 30 has multiple inner peripheral longitudinal walls 203, each with a different diameter. Therefore, the inner peripheral longitudinal walls 203 divide the internal cavity 30 into a central cavity 301 and multiple annular cavities.

[0053] like Figure 3 , Figure 5 and Figure 7 As shown, in some embodiments of the present invention, the second elastic membrane 40 includes a second elastic bottom wall 401, a pleated side wall 402, and a second top wall 403. The second top wall 403 is connected to the lower surface of the main body 10. The second top wall 403 and the second elastic bottom wall 401 are connected by the pleated side wall 402 to form an inflation chamber 50. The inflation chamber 50 is connected to the second ventilation pipe.

[0054] Specifically, the pleated sidewall 402 of the second elastic membrane 40 can unfold during inflation, and the second elastic bottom wall 401 expands downward to block the vents 3021 on the first elastic bottom wall 202. This ensures that the first elastic bottom wall 202 can expand and press the wafer W onto the polishing pad 200 when positive pressure gas is input. Alternatively, after the wafer W is polished and needs to be removed from the first elastic membrane 20, the second elastic membrane 40 can contract through the pleated sidewall 402, opening the vents 3021 that were originally blocked, allowing gas to be blown out through the vents 3021, thus blowing the wafer W off the first elastic membrane 20 and achieving smooth separation of the wafer W from the carrier head 100.

[0055] Furthermore, the design of the pleated sidewall 402 of the second elastic film 40 prevents it from touching or abutting the inner circumferential longitudinal wall 203 or outer circumferential longitudinal wall 201 of the first elastic film 20 after inflation. This would prevent the inner circumferential longitudinal wall 203 and outer circumferential longitudinal wall 201 from bending, which would cause the first elastic bottom wall 202 of the first elastic film 20 to be unable to stably press the wafer W onto the polishing pad 200, resulting in uneven polishing of the wafer W.

[0056] Furthermore, such as Figure 2 As shown, when the inflation chamber 50 is inflated, the second elastic membrane 40 expands, and the width of the second elastic bottom wall 401 is the same as the width of the first elastic bottom wall 202, thus blocking the air hole 3021. Furthermore, the pleated sidewall 402 and the inner circumferential longitudinal wall 203 are not in contact.

[0057] Specifically, when the second elastic membrane 40 expands, its second elastic bottom wall 401 extends to a structure with the same width as the first elastic bottom wall 202. This ensures that the pressure is evenly distributed on the first elastic bottom wall 202 corresponding to the annular cavity 302, and also guarantees complete sealing of the pores 3021 on the first elastic bottom wall 202. This prevents incomplete sealing of the pores 3021, which could lead to liquids (such as water or polishing fluid) and debris or particles generated during the wafer W polishing process entering the annular cavity 302 through the pores 3021, thereby corroding the metal structure inside the support head 100. The pleated sidewalls 402 of the second elastic membrane 40 do not contact the inner circumferential longitudinal wall 203 after the second elastic membrane 40 expands, preventing the inner circumferential longitudinal wall 203 from bending. This would cause the first elastic bottom wall 202 of the first elastic membrane 20 to also bend due to the bending of the inner circumferential longitudinal wall 203. Therefore, it is impossible to stably press the wafer W onto the polishing pad 200, resulting in uneven polishing of the wafer W and difficulty in controlling the adsorption pressure of the first elastic bottom wall 202 on the wafer W.

[0058] In some embodiments of the present invention, such as Figure 7 As shown, the second top wall 403 of the second elastic membrane 40 has the same width as the second elastic bottom wall 401.

[0059] Specifically, at this time, the width of the second top wall 403 of the second elastic membrane 40 is the same as the width of the second elastic bottom wall 401, thereby forming a shape as shown in the figure. Figure 7The cross-section shown is a rectangular structure with certain folds along its long side. The second top wall 403 and the second elastic bottom wall 401 are connected by folded side walls 402. This structural design ensures that the second elastic membrane 40 can seal the vent 3021 when it expands, while simultaneously preventing the folded side walls 402 from touching or abutting against the inner circumferential longitudinal wall 203. Simultaneously, due to the effect of the folded side walls 402, the second elastic bottom wall 401 can open the vent 3021 when the second elastic membrane 40 contracts.

[0060] In some embodiments of the present invention, such as Figure 3 and Figure 5 As shown, the width of the second top wall 403 of the second elastic membrane 40 is half the width of the first top wall 204, and the width of the second elastic bottom wall 401 is two-thirds the width of the first elastic bottom wall 202.

[0061] Specifically, the cross-sectional structure of the second elastic membrane 40 is a trapezoidal structure with pleats on both sides. This ensures that the second elastic membrane 40 can seal the pores 3021 when it expands, while also preventing the pleated sidewalls 402 from touching or abutting against the inner longitudinal wall 203. Simultaneously, due to the effect of the pleated sidewalls 402, the second elastic bottom wall 401 allows the pores 3021 to open when the second elastic membrane 40 contracts. Furthermore, the overall structure saves more material.

[0062] Among them, such as Figure 3 and Figure 5 As shown, the width of the second top wall 403 is half the width of the first top wall 204, the width of the second elastic bottom wall 401 is two-thirds the width of the first elastic bottom wall 202, and the second elastic bottom wall 401 has an open vent 3021.

[0063] Specifically, when the second elastic membrane 40 is in a contracted state, the second elastic bottom wall 401 also contracts to a structure with a width two-thirds that of the first elastic bottom wall 202, thereby opening the vent 3021. Gas is then allowed to pass through the vent 3021. When the wafer W polishing operation is completed and it needs to be placed in a predetermined position, the second elastic membrane 40 can be contracted, and the vent 3021 opened, allowing gas to be blown onto the wafer W through the vent 3021, enabling the wafer W to detach smoothly from the carrier head 100. This prevents the wafer W from being pressed by the carrier head 100 for an extended period of time, causing it to be unable to detach smoothly.

[0064] Furthermore, in this embodiment, the second elastic membrane 40 and the first elastic membrane 20 satisfy the following relationship:

[0065] b>5t1;

[0066] Where t1 is the thickness of the sidewall of the second elastic membrane;

[0067] t2 is the thickness of the inner circumferential longitudinal wall 203;

[0068] b is the width of a single fold in the folded sidewall 402.

[0069] Specifically, such as Figure 3 As shown, the sidewall of the second elastic membrane 40, represented by the waist of the trapezoid in its cross-section, has a thickness of t1. The thickness of the inner longitudinal wall 203 is t2. Therefore, it can be seen that the sidewall thickness of the second elastic membrane 40 is thinner than the inner longitudinal wall 203 of the first elastic membrane 20. Consequently, its elasticity is higher than that of the inner longitudinal wall 203. This allows for better elastic deformation, effectively sealing the pores 3021 and preventing their expansion from putting pressure on the first elastic membrane 20.

[0070] In addition, the sidewalls of the second elastic membrane 40 can also be like Figure 5 and Figure 7 The diagram shows a pleated sidewall. The number and width of the pleats in the pleated sidewall 402 of the second elastic membrane 40 can be determined by satisfying the formula above. b>5t1, ensuring that the second elastic membrane 40 seals the pores 3021 when it expands, and also preventing the folded sidewall 402 from touching or abutting the inner longitudinal wall 203 after it expands.

[0071] like Figure 5 and Figure 7 As shown, the width of the folds in the folded sidewall 402 is as follows: Figure 5 As shown in H in the diagram. After the second elastic membrane 40 is pressurized and expanded, it can completely cover the chamber, and the pressure can be applied evenly to the air film base plate without affecting the sidewalls of the elastic membrane.

[0072] In some embodiments of the present invention, the hardness of the second elastic membrane 40 is less than that of the first elastic membrane 20, and the hardness of the second elastic membrane 40 ranges from 37HA to 42HA.

[0073] Specifically, the second elastic membrane 40 has a lower hardness than the first elastic membrane 20, meaning it possesses greater elasticity. The hardness of the second elastic membrane 40 ranges from 37HA to 42HA. Therefore, when gas is introduced, the second elastic membrane 40 can undergo greater elastic deformation. This ensures that the deformation of the first and second elastic membranes 20 and 40 is more consistent due to gas pressure changes, thereby preventing a pressure difference between the internal chamber 30 of the first elastic membrane 20 and the gas-filled chamber 50 of the second elastic membrane 40, which could damage the wafer W.

[0074] This invention is not limited thereto. In some embodiments of this invention, multiple concentric annular cavities 302 are provided. The second elastic membrane 40 can be disposed in the outermost annular cavity 302. This allows multiple air holes 3021 to be formed on the first elastic bottom wall 202 corresponding to the annular cavity 302, so that when the wafer W is detached from the support head 100, the blown gas can more easily detach the wafer W from the support head 100, and the force received is more uniform.

[0075] A chemical mechanical polishing apparatus 1000 according to a second aspect embodiment of the present invention includes a support head 100, which is the support head 100 of the first aspect embodiment.

[0076] In some embodiments of the present invention, such as Figure 8 As shown, the chemical mechanical polishing apparatus 1000 may include a support head 100. The support head 100 may be the support head 100 described in the first aspect embodiment above. Furthermore, the chemical mechanical polishing apparatus 1000 may also include a polishing pad 200, a polishing disc 300, a dresser 400, and a liquid supply unit 500. The polishing pad 200 is disposed on the upper surface of the polishing disc 300 and rotates together with it along an axis Ax. The axis Ax is as follows... Figure 8 As shown in the diagram. The carrier head 100 is horizontally movable and positioned above the polishing pad 200. The lower surface of the carrier head 100 can hold the wafer W to be polished. The dresser 400 includes a dresser arm and a dresser head, which are disposed on one side of the polishing disk 300. The dresser arm drives the rotating dresser head to swing and dress the surface of the polishing pad 200. The liquid supply unit 500 is disposed above the polishing pad 200 to distribute the polishing liquid onto the surface of the polishing pad 200.

[0077] The chemical mechanical polishing apparatus 1000 provided according to the embodiments of this application has the same beneficial effects as the carrier head 100 of the first aspect embodiment due to having the carrier head 100 of the first aspect embodiment. Positive and negative pressure gases can be provided to the central cavity 301 and multiple annular cavities 302 between the first elastic membranes 20 through the first ventilation pipe, and positive and negative pressure gases can be provided to the interior of the second elastic membrane 40 through the second ventilation pipe. The first elastic bottom wall 202 of the annular cavity 302 with the second elastic membrane 40 has vent holes 3021, thereby ensuring stable adsorption of the wafer W by expanding and blocking the vent holes 3021 during wafer W adsorption, and preventing liquids (e.g., water or polishing fluid) and debris or particles generated during the polishing process from entering the interior of the annular cavity 302 through the vent holes 3021, thus preventing corrosion of the metal structure inside the carrier head 100. After polishing, gas can be blown out through the vent 3021 to detach the wafer W from the first elastic bottom wall 202 of the first elastic film 20. Furthermore, the overall structure is simple, requiring no additional equipment or structures, making it convenient and quick.

[0078] A wafer polishing method according to a third aspect of the present invention, such as Figure 9 As shown, the wafer polishing method is applicable to controlling the carrier head 100 of the first aspect embodiment, and its process is as follows: Figure 9 As shown, it includes:

[0079] Step S1: Inflate the second elastic membrane through the second vent pipe of the bearing head to expand the second elastic membrane and seal the air hole;

[0080] Specifically, in this step, the second elastic membrane 40 is inflated by the second venting pipe, which can cause the second elastic membrane 40 to expand and block the air hole 3021, thereby enabling the annular cavity 302 to form a sealed cavity.

[0081] Step S2: Control the carrier head to move to the wafer W pick-up position, and the first elastic bottom wall of the first elastic film is attached to the wafer W;

[0082] Specifically, in this step, the carrier head 100 moves to the wafer W gripping position, and the first elastic membrane 20 contacts the wafer W. At this time, the pores 3021 of the first elastic membrane 20 are blocked by the second elastic membrane 40, so the first elastic membrane 20 can be completely attached to the wafer W.

[0083] Step S3: Control the first ventilation pipe to create a negative pressure in the internal cavity, so that the middle part of the first elastic bottom wall separates from the wafer W and adsorbs the wafer W;

[0084] Specifically, in this step, the first ventilation pipe creates a negative pressure in the internal chamber 30 of the first elastic membrane 20, and the middle part of the first elastic bottom wall 202 of the first elastic membrane 20 separates from the wafer W, thereby adsorbing the wafer W.

[0085] Step S4: Control the carrier head to move the wafer W to the polishing pad, and lower the height of the carrier head so that the wafer W fits against the polishing pad;

[0086] Specifically, the carrier head 100 is controlled to move the wafer W synchronously to the polishing pad 300. The carrier head 100 lowers its height so that the wafer W fits against the polishing pad 200, which facilitates the subsequent polishing operation of the wafer W.

[0087] Step S5: Control the first venting pipe to form positive pressure on the internal chamber, so that the first elastic bottom wall contacts the surface of the wafer W and presses the wafer W onto the polishing pad. At the same time, the second venting pipe inflates the second elastic membrane to seal the pores, and the polishing pad polishes the surface of the wafer W.

[0088] Specifically, in this step, positive pressure gas is injected into the internal chamber 30, the first elastic membrane 20 expands, and the first elastic bottom wall 202 completely adheres to the surface of the wafer W, pressing the wafer W onto the polishing pad 200. The second elastic membrane 40 inflates and seals the vent 3021, thereby enabling the wafer to be stably pressed onto the polishing pad 200, thus stabilizing the position of the wafer W and ensuring uniform surface polishing of the wafer W.

[0089] Step S6: After polishing, control the first ventilation pipe to create a negative pressure in the internal cavity so that the middle part of the first elastic bottom wall separates from the wafer W, adsorbs the wafer W and moves it to the wafer W placement location.

[0090] Specifically, in this step, after polishing is completed, the internal chamber 30 forms a negative pressure, causing the middle part of the first elastic bottom wall 202 to detach from the wafer W and re-adsorb the wafer W. The movement of the polishing head drives the wafer W to the wafer W placement location.

[0091] Step S7: Stop the second ventilation pipe from filling with gas, so that the second elastic membrane contracts and opens the vent. The first ventilation pipe blows gas out through the vent, so that the wafer W is separated from the first elastic bottom wall of the first elastic membrane.

[0092] Specifically, in this step, the second elastic membrane 40 contracts and opens the vent 3021, allowing gas to be blown out through the vent 3021. Therefore, the wafer W can be smoothly detached from the carrier head 100 by the gas being blown out through the vent 3021. This enables rapid gripping and placement of the wafer W and also prevents damage to the wafer W during removal.

[0093] According to the wafer polishing method of the third aspect embodiment of this application, the wafer polishing method is applicable to controlling the carrier head 100 of the first aspect embodiment, and therefore has the same beneficial effects as the carrier head 100 of the first aspect embodiment. A first venting conduit can provide positive and negative pressure gas to the central cavity 301 and multiple annular cavities 302 between the first elastic membranes 20, and a second venting conduit can provide positive and negative pressure gas to the interior of the second elastic membrane 40. The first elastic bottom wall 202 of the annular cavity 302, which is provided with the second elastic membrane 40, has vent holes 3021. Therefore, when adsorbing the wafer W, the second elastic membrane 40 expands to block the vent holes 3021, thereby ensuring stable adsorption of the wafer W and preventing liquids (e.g., water or polishing fluid) and debris or particles generated during the polishing process from entering the interior of the annular cavity 302 through the vent holes 3021, thus preventing corrosion of the metal structure inside the carrier head 100. After polishing, gas can be blown out through the vent 3021 to detach the wafer W from the first elastic bottom wall 202 of the first elastic film 20. Furthermore, the overall structure is simple, requiring no additional equipment or structures, making it convenient and quick.

[0094] In another embodiment of this application, the chemical mechanical polishing apparatus may further include a controller, the controller being used to perform actions such as... Figure 9 The method shown.

[0095] Another embodiment of this application provides a computer storage medium storing a computer program that, when executed by a processor, implements the wafer grinding time determination method as described above.

[0096] Another embodiment of this application provides a computer program product, including computer instructions that instruct a computing device to perform operations corresponding to the wafer grinding time determination method described above.

[0097] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A carrier head for wafer processing, characterized in that, include: The main body is circular, and its interior has a first vent pipe and a second vent pipe; A first elastic membrane defines a central cavity and a plurality of annular cavities between itself and the surface of the main body. The plurality of annular cavities are concentric with the central cavity. The central cavity and the plurality of annular cavities are connected to the first ventilation channel so that the lower surface of the first elastic membrane can adsorb or detach the wafer. At least one of the plurality of annular cavities has a plurality of pores on its surface facing the wafer. A second elastic membrane is located within the annular cavity having a plurality of the pores, and the second elastic membrane is connected to the second venting conduit to block and open the pores; The sidewalls of the second elastic membrane are pleated sidewalls, and satisfy the following conditions: b > 5 t 1, among which, t 1 represents the thickness of the sidewall of the second elastic membrane. ，b The width of a single fold in the folded sidewall.

2. The bearing head according to claim 1, characterized in that, The first elastic membrane includes an outer peripheral longitudinal wall, a first elastic bottom wall, a plurality of inner peripheral longitudinal walls, and a first top wall. The first top wall is connected to the lower surface of the main body. The first elastic bottom wall is connected to the lower surface of the main body through the outer peripheral longitudinal wall to form an internal cavity. The plurality of inner peripheral longitudinal walls are all concentrically arranged inside the outer peripheral longitudinal wall, and the diameters of the plurality of inner peripheral longitudinal walls are different, so as to divide the internal cavity into a central cavity and a plurality of annular cavities.

3. The bearing head according to claim 2, characterized in that, The second elastic membrane includes a second elastic bottom wall, a pleated side wall, and a second top wall. The second top wall is connected to the lower surface of the main body. The second top wall and the second elastic bottom wall are connected by the pleated side wall to form an inflation chamber. The inflation chamber is connected to the second ventilation pipe.

4. The bearing head according to claim 3, characterized in that, When the inflation chamber is inflated, the second elastic membrane expands, and the width of the second elastic bottom wall is the same as the width of the first elastic bottom wall, thus blocking the air hole.

5. The bearing head according to claim 4, characterized in that, The second top wall of the second elastic membrane has the same width as the second elastic bottom wall.

6. The bearing head according to claim 4, characterized in that, The width of the second top wall of the second elastic membrane is half the width of the first top wall, and the width of the second elastic bottom wall is two-thirds the width of the first elastic bottom wall.

7. The bearing head according to any one of claims 1-6, characterized in that, The hardness of the second elastic membrane is less than that of the first elastic membrane, and the hardness of the second elastic membrane ranges from 37HA to 42HA.

8. A wafer polishing method, characterized in that, The wafer polishing method is applicable to controlling the carrier head according to any one of claims 1-7, including: The second elastic membrane is inflated through the second venting pipe of the bearing head to expand and seal the air pores; The carrier head is controlled to move to the wafer pick-up position, and the first elastic bottom wall of the first elastic film is in contact with the wafer. The first ventilation pipe is controlled to create a negative pressure in the internal cavity, so that the middle part of the first elastic bottom wall is separated from the wafer and the wafer is adsorbed. The central cavity and multiple annular cavities constitute the internal cavity. The carrier head is controlled to move the wafer to the polishing pad, and the height of the carrier head is lowered so that the wafer fits against the polishing pad; The first ventilation pipe is controlled to create positive pressure on the internal chamber, so that the first elastic bottom wall contacts the surface of the wafer and presses the wafer onto the polishing pad. At the same time, the second ventilation pipe inflates the second elastic membrane to seal the pores, and the polishing pad polishes the surface of the wafer. After polishing, the first ventilation pipe is controlled to create a negative pressure in the internal cavity, so that the middle part of the first elastic bottom wall is separated from the wafer, adsorbs the wafer, and moves it to the wafer placement location. The second ventilation line is stopped from inflating, causing the second elastic membrane to contract and open the vent. The first ventilation line blows gas out through the vent, causing the wafer to separate from the first elastic bottom wall of the first elastic membrane.

9. A chemical mechanical polishing device, characterized in that, include: The bearing head is the bearing head according to any one of claims 1-7.

10. The chemical mechanical polishing apparatus according to claim 9, characterized in that, Also includes: The controller is used to perform the following steps: The second elastic membrane is inflated through the second venting pipe of the bearing head to expand and seal the air pores; The carrier head is controlled to move to the wafer pick-up position, and the first elastic bottom wall of the first elastic film is in contact with the wafer. The first ventilation pipe is controlled to create a negative pressure in the internal cavity, so that the middle part of the first elastic bottom wall is separated from the wafer and the wafer is adsorbed. The central cavity and multiple annular cavities constitute the internal cavity. The carrier head is controlled to move the wafer to the polishing pad, and the height of the carrier head is lowered so that the wafer fits against the polishing pad; The first ventilation pipe is controlled to create positive pressure on the internal chamber, so that the first elastic bottom wall contacts the surface of the wafer and presses the wafer onto the polishing pad. At the same time, the second ventilation pipe inflates the second elastic membrane to seal the pores, and the polishing pad polishes the surface of the wafer. After polishing, the first ventilation pipe is controlled to create a negative pressure in the internal cavity, so that the middle part of the first elastic bottom wall is separated from the wafer, adsorbs the wafer, and moves it to the wafer placement location. The second ventilation line is stopped from inflating, causing the second elastic membrane to contract and open the vent. The first ventilation line blows gas out through the vent, causing the wafer to separate from the first elastic bottom wall of the first elastic membrane.

11. A computer storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the wafer polishing method as described in claim 8.

12. A computer program product, characterized in that, Includes computer instructions that instruct a computing device to perform operations corresponding to the wafer polishing method as described in claim 8.

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