Upper grinding and polishing disc system

Abstract

The invention provides an upper grinding and polishing disc system, which relates to the technical field of semiconductor processing and comprises an upper grinding and polishing disc, a disc body unit, a disc cover unit, a disc core unit and a connecting sleeve, the upper grinding and polishing disc is fixedly arranged below the disc body unit; the tray cover unit is fixedly connected above the tray body unit, and a cavity is formed between the tray cover unit and the tray body unit; the disc core unit is wrapped in the cavity; one end of the connecting sleeve is fixedly connected to an installation foundation, and the other end is fixedly connected with the middle of the disc core unit; the disc core unit comprises a first magnetic module, and at least one of the lower surface of the disc cover unit and the upper surface of the disc body unit is provided with a first magnetic element used for being in magnetic fit with the first magnetic module. By controlling the magnetic pole direction of the first magnetic module and / or the first magnetic element and the magnetic field intensity between the first magnetic module and the first magnetic element, the magnetic force direction and the magnetic force value applied to the disc cover unit and the disc body unit by the disc core unit are controlled. And the adjusting range, the control precision and the grinding and polishing quality of the wafer pressure are improved.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor processing, and more particularly, to an upper polishing pad system. Background Art

[0002] In a grinding and polishing apparatus for processing multiple semiconductor wafers in one operation, the upper polishing pad is a key component. The diameter of the upper polishing pad is relatively large, usually about 1000 mm, and some exceed 1500 mm.

[0003] As shown in Figure 1 , Figure 2 , Figure 3 FIGURES 1 - 3 show a schematic diagram of a prior art semiconductor wafer grinding and polishing apparatus, which mainly consists of an upper platen part A1, a universal joint A11, an upper platen drive unit A12, a lower platen part B1, a lower platen drive unit B11, and a machine base C1. The upper platen part A1 is driven by the upper platen drive unit A12 through the universal joint A11. The upper platen part A1 can rotate clockwise and counterclockwise and can change speed. The upper platen part A1 has 4 degrees of freedom and is a floating rotation structure. The lower surface of the upper platen part A1 is the upper polishing pad; the lower platen part B1 is driven by the lower platen drive unit B11, can rotate clockwise and counterclockwise, and can change speed. The lower platen part B1 has only 1 degree of rotational freedom and is a rigid rotation structure. The upper surface of the lower platen part B1 is the lower polishing pad; between the upper polishing pad of the upper platen part A1 and the lower polishing pad of the lower platen part B1 is a planetary wheel part D1, and the planetary wheel contains wafers D11. Through the respective rotations of the upper polishing pad, the lower polishing pad, and the planetary wheel, grinding or polishing of multiple wafers is achieved.

[0004] During the processing, the upper polishing pad needs to be pressurized when polishing the wafer. In the prior art, the pressurization method is mainly hydraulic or pneumatic, and the pressurization force is achieved by adjusting the pressure (pressure) of the hydraulic or pneumatic pressure. With the continuous improvement of the grinding and polishing processing accuracy and efficiency of the wafer, the accuracy of the pressure provided by the upper polishing pad to the wafer is also continuously improved.

[0005] When no additional pressure is applied to the upper polishing pad, the self - weight of the upper polishing pad constitutes the reference pressure on the wafer. In the prior art, when using a pneumatic or hydraulic method to apply an additional pressure to the upper polishing pad, there are the following defects: The control of the downward pressure is not precise enough to meet the requirements; The downward pressure adjustment range is small and cannot meet the working scenario where the downward pressure is less than the self - weight; The mechanical vibration caused by hydraulic and pneumatic control limits the grinding and polishing quality. Summary of the Invention

[0006] The purpose of the present application is to provide an upper polishing disc system, aiming to solve the problems in related technologies such as how to improve the adjustment range of the pressure on the wafer, the control accuracy, and the polishing quality.

[0007] Additional aspects and advantages of the present application will be partly set forth in the description below, and partly will be obvious from the description, or can be learned through the practice of the present application.

[0008] According to the present application, there is provided an upper polishing disc system, which is characterized in that it includes an upper polishing disc, a disc body unit, a disc cover unit, a disc core unit, and a connecting sleeve; The upper polishing disc is fixedly installed below the disc body unit; The disc cover unit is fixedly connected above the disc body unit, and a cavity is formed between the disc cover unit and the disc body unit; The disc core unit is wrapped in the cavity; One end of the connecting sleeve is used to be fixedly connected to a mounting base, and the other end passes through the disc cover unit and is fixedly connected to the middle of the disc core unit; The disc core unit includes a first magnetic module, and at least one of the lower surface of the disc cover unit and the upper surface of the disc body unit is provided with a first magnetic element for forming a magnetic fit with the first magnetic module; By controlling the magnetic pole directions of the first magnetic module and / or the first magnetic element and the magnetic field strength between the two, the magnetic force direction and magnetic force value applied by the disc core unit to the disc cover unit and the disc body unit are controlled, and further the downward pressure value applied by the upper polishing disc is controlled.

[0009] In an exemplary embodiment of the present application, the first magnetic pole module has magnetic poles at its upper and lower ends; Through control, the magnetic pole direction of the upper magnetic pole of the first magnetic module is opposite to the magnetic pole direction of the first magnetic element on the lower surface of the disc cover unit facing the upper magnetic pole of the first magnetic module; and / or, the magnetic pole direction of the lower magnetic pole of the first magnetic pole module is the same as the magnetic pole direction of the first magnetic element on the upper surface of the disc body unit facing the lower magnetic pole of the first magnetic module.

[0010] In an exemplary embodiment of the present application, the first magnetic pole module has magnetic poles at its upper and lower ends; Through control, the magnetic pole direction of the upper magnetic pole of the first magnetic module is the same as the magnetic pole direction of the first magnetic element on the lower surface of the disc cover unit facing the upper magnetic pole of the first magnetic module; and / or, the magnetic pole direction of the lower magnetic pole of the first magnetic pole module is opposite to the magnetic pole direction of the first magnetic element on the upper surface of the disc body unit facing the lower magnetic pole of the first magnetic module.

[0011] In an exemplary embodiment of the present application, the first magnetic module is an iron core coil structure, and the first magnetic elements of the disc cover unit and the disc body unit are both permanent magnet structures, and the magnetic pole directions facing the first magnetic module are the same; The magnetic pole direction at both ends of the first magnetic module is changed by controlling the input direction of the coil current; the magnetic force value exerted by the first magnetic module on the magnet of the disc cover unit and / or the magnet of the disc body unit is changed by controlling the magnitude of the coil current.

[0012] In an exemplary embodiment of the present application, the first magnetic module is an integral modular structure, including a first iron core, a first coil, an upper cover, and a lower cover.

[0013] In an exemplary embodiment of the present application, the first iron core is in an "I" shape structure, the first coil is wound around the waist of the first iron core, and after the first coil is energized, the first iron core forms four magnetic poles.

[0014] In an exemplary embodiment of the present application, the disc core unit further includes a disc core body, the first magnetic modules are multiple groups, and the multiple groups of the first magnetic modules are embedded in the disc core body, and the multiple groups of the first magnetic modules are radially distributed around the center of the disc core body on the disc core body; The disc cover unit further includes a disc cover body, and the disc body unit further includes a disc body; the first magnetic elements of the disc cover unit and / or the disc body unit are multiple groups, and the multiple groups of the first magnetic elements are installed on the lower surface of the disc cover body and / or the upper surface of the disc body, and are in a structure of multiple concentric rings.

[0015] In an exemplary embodiment of the present application, a motor rotor is fixedly provided on the inner circumference of the disc cover unit, and a motor stator is fixedly provided on the outer circumference of the disc core unit. The motor rotor and the motor stator constitute a motor unit, and the motor unit can drive the disc cover unit and the disc body unit to rotate relative to the disc core unit.

[0016] In an exemplary embodiment of the present application, gaps are provided between the disc core unit and the circumferential cavity walls of the cavities formed between the lower surface of the disc cover unit, the upper surface of the disc body unit, and between the disc cover unit and the disc body unit.

[0017] In an exemplary embodiment of the present application, a convex sleeve is fixedly provided at the central part of the disc core unit, and the convex sleeve is fixedly connected with the connecting sleeve; A centering unit is provided in the convex sleeve. The centering unit includes a centering shaft and an aligning bearing. The centering shaft is arranged along the axis direction of the convex sleeve. The aligning bearing is sleeved on the centering shaft. The inner ring of the aligning bearing is fixed to the centering shaft, and the outer ring of the aligning bearing can slide up and down in the convex sleeve.

[0018] In an exemplary embodiment of the present application, the centering unit further includes a second magnetic module and a second magnetic element. The second magnetic element is fixedly connected to the centering shaft, and the second magnetic module is fixedly connected to the disk core unit. The second magnetic module and the second magnetic element form a coupling pair, and there is a gap between the second magnetic module and the second magnetic element.

[0019] In an exemplary embodiment of the present application, the second magnetic module includes a second iron core and a second coil, and the second magnetic element is a permanent magnet structure. When the second coil is energized, the second magnetic module and the second magnetic element generate a mutual force. When the magnitude or direction of the current and voltage parameters during energization changes, the direction and magnitude of the force will also change accordingly.

[0020] In an exemplary embodiment of the present application, the disk body is made of a non-magnetic conductive material.

[0021] In an exemplary embodiment of the present application, the upper polishing disk has plasticity. By adjusting the current of each first magnetic module, the magnitude and direction of the electromagnetic force between the first magnetic module and the first magnetic element are adjusted, so as to change the polishing surface shape of the upper polishing disk.

[0022] In an exemplary embodiment of the present application, The polishing surface shape of the upper polishing disk is obtained by the following formula: ; where is the deformation amount at the center of the polishing surface shape, is the deformation amount of the polishing surface shape affected by the attraction of the first magnetic module, is the deformation amount of the polishing surface shape affected by the repulsion of the first magnetic module.

[0023] In an exemplary embodiment of the present application, the calculation of and is as follows: ; ; ; ; ; ; ; In the formula, is the radius of the polished surface profile of the upper polishing disc, is the distance from the outermost edge of the cross-section of the first magnetic element to the center of the polished surface profile of the upper polishing disc, is the distance from the innermost edge of the cross-section of the first magnetic element to the center of the polished surface profile of the upper polishing disc, is the flexural rigidity, is the elastic modulus of the material, is the thickness of the disc body, is the Poisson's ratio of the material, is the pressure exerted on the upper polishing disc, is the electromagnetic force exerted by the first magnetic module on the upper polishing disc, is the number of turns of the coil, is the current, is the vacuum permeability, is the air gap thickness, is the cross-sectional area of the magnetic circuit.

[0024] In an exemplary embodiment of the present application, the upper polishing disc is plastic; by adjusting the current of each group of the first magnetic modules and / or, the magnitude and direction of the electromagnetic force between the first magnetic module and the first magnetic element are adjusted, so as to change the polished surface profile of the upper polishing disc.

[0025] In an exemplary embodiment of the present application, the upper polishing disc is plastic; by adjusting the current of each group of the first magnetic modules, the magnitude and direction of the electromagnetic force between the first magnetic module and the first magnetic element are adjusted, so as to change the polished surface profile of the upper polishing disc.

[0026] The exemplary embodiments of the present application may have some or all of the following beneficial effects: 1. In an upper polishing pad system provided by an exemplary embodiment of the present application, the disk core unit is fixedly connected to the mounting base through a connecting sleeve, so that the disk core unit and the mounting base are relatively fixed. By energizing at least one of the first magnetic module and the first magnetic element, a magnetic field is formed between the first magnetic module and the first magnetic element, and a magnetic force is generated. The magnetism generated by the disk core unit can act on the disk cover unit, the disk body unit, or both the disk cover unit and the disk body unit simultaneously, so as to accurately adjust the pressure exerted by the upper polishing pad on the wafer. Specifically, the first magnetic module can be energized to generate magnetic poles, and the first magnetic element can be set as a permanent magnet; or the first magnetic module can be set as a permanent magnet, and the first magnetic element can be energized to generate magnetic poles; or both can be set as electromagnetic structures that generate magnetic poles when energized. The first magnetic element can be installed on the disk cover unit or the disk body unit; when the first magnetic element is installed on the disk cover unit, if the first magnetic module generates a magnetic attraction force with the first magnetic element, and at this time the magnetic force received by the disk cover unit is downward, the pressure of the upper polishing pad on the wafer can be increased. If the first magnetic module generates a magnetic repulsion force with the first magnetic element, and at this time the magnetic force received by the disk cover unit is upward, the pressure of the upper polishing pad on the wafer can be reduced. When the first magnetic element is installed on the disk body unit, if the first magnetic module generates a magnetic attraction force with the first magnetic element, and at this time the magnetic force received by the disk body unit is upward, the pressure of the upper polishing pad on the wafer can be reduced. If the first magnetic module generates a magnetic repulsion force with the first magnetic element, and at this time the magnetic force received by the disk body unit is downward, the pressure of the upper polishing pad on the wafer can be increased. Of course, the first magnetic element can also be set in two groups, and the two electromagnetic elements are respectively installed on the disk cover unit and the disk body unit. When the first magnetic module and / or the first magnetic element is energized, the first magnetic module generates a magnetic force with the first magnetic element in the disk cover unit and also generates a magnetic force with the first magnetic element in the disk body unit. It can be understood that the sum of the weights of the upper polishing pad, the disk body unit, and the disk cover unit can be used as the reference pressure for generating pressure on the wafer. On this basis, if the pressure required by the wafer is greater than the reference pressure, the magnetic force acting downward on the upper polishing pad can be generated through the magnetic field generated by the first magnetic module and the first magnetic element to increase the pressure on the wafer; if the pressure required by the wafer is less than the reference pressure, the magnetic force acting upward on the upper polishing pad can be generated through the magnetic field generated by the first magnetic module and the first magnetic element to reduce the pressure on the wafer. In summary, by adjusting the parameters of the input current and / or voltage, the intensity and direction of the magnetic force can be controlled, and thus the pressure of the upper polishing pad on the wafer can be adjusted.Compared with the traditional hydraulic or pneumatic methods, the magnetic force used in this application eliminates the compressibility and fluidity of gases and liquids, thereby improving the precision of controlling the pressure on the wafer. By adjusting the parameters of the input current and / or voltage in this application, the direction of the magnetic force on the upper polishing pad can be changed, so that on the basis of the reference pressure, the pressure on the wafer can be increased or decreased. Thus, the adjustment range of the pressure on the wafer is expanded. The magnetic force used in this application also eliminates the mechanical vibration in the traditional hydraulic and pneumatic controls, thereby further improving the polishing quality of the wafer. 2. In an upper polishing pad system provided by the exemplary embodiment of this application, the upper polishing pad and the disk body are set to be plastic, and a plurality of first magnetic modules are provided and radially distributed around the center of the disk core body. By adjusting the magnitude and direction of the electromagnetic forces generated by the first magnetic modules and / or the second magnetic modules at different positions, the surface shape of the polishing disk can be changed, so that the upper polishing pad can meet different processing requirements.

[0027] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. Brief Description of the Drawings

[0028] The drawings here are incorporated into the specification and form a part of this specification, showing the embodiments consistent with this application, and are used together with the specification to explain the principles of this application. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic cross-sectional view of a semiconductor wafer grinding and polishing processing device in the prior art; Figure 2 It is a three-dimensional schematic diagram of a lower polishing device in the prior art; Figure 3 It is a three-dimensional schematic diagram of an upper polishing pad system in the prior art; Figure 4 It shows a three-dimensional cross-sectional schematic diagram of a magnetic levitation semiconductor upper polishing pad system in an embodiment of this application; Figure 5 It shows a front view schematic diagram of a magnetic levitation semiconductor upper polishing pad system in an embodiment of this application; Figure 6 It shows a simplified cross-sectional schematic diagram of a magnetic levitation semiconductor upper polishing pad system in an embodiment of this application; Figure 7Shows a cross-sectional schematic diagram of a magnetic levitation type semiconductor upper polishing and lapping disc system in an embodiment of the present application; Figure 8 is Figure 7 a partial enlarged schematic diagram of part A of; Figure 9 is Figure 7 a partial enlarged schematic diagram of part B of; Figure 10 is Figure 7 a partial enlarged schematic diagram of part C of; Figure 11 Shows a three-dimensional cross-sectional schematic diagram of a disc core unit in an embodiment of the present application; Figure 12 Shows a three-dimensional exploded schematic diagram of a disc core unit in an embodiment of the present application; Figure 13 Shows a three-dimensional schematic diagram of a magnetic core module one in an embodiment of the present application; Figure 14 Shows an exploded schematic diagram of a magnetic core module one in an embodiment of the present application; Figure 15 Shows in calculating the polishing surface profile of the upper polishing and lapping disc in an embodiment of the present application 、 、 the distance schematic diagram referred to.

[0030] Explanation of reference numerals: A1, upper disc part; A11, universal joint; A12, upper disc drive unit; B1, lower disc part; B11, lower disc drive unit; C1, machine base; D1, planetary wheel part; D11, wafer; 1, upper polishing and lapping disc; 2, disc body unit; 3, disc cover unit; 4, disc core unit; 5, centering unit; 6, disc frame; 7, connecting sleeve; 8, first magnetic module; 21, magnetic core one; 22, disc body; 23, sealing ring; 31, magnetic core two; 32, motor rotor; 33, disc cover body; 41, motor stator; 42, disc core body; 51, centering shaft; 52, aligning bearing; 53, second magnetic module; 54, magnetic core three; 55, screw; 71, screw one; 72, screw two; 81, iron core one; 82, coil one; 83, upper protective cover; 84, lower protective cover. Detailed implementation manners

[0031] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present application and are not necessarily drawn to scale.

[0032] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another component, these terms are used in this specification only for convenience, for example, according to the direction of the example in the drawings. It can be understood that if the device of the icon is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" another structure, it may mean that a structure is integrally formed on another structure, or that a structure is "directly" disposed on another structure, or that a structure is "indirectly" disposed on another structure through another structure.

[0033] The terms "a", "an", "the" and "at least one" are used to denote the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc.; the terms "first", "second" are used only as labels and are not a limitation on the quantity of their objects.

[0034] Referring to Figure 4 、 Figure 5 and Figure 6 As shown, in an embodiment of the present application, an upper polishing pad system is provided, including an upper polishing pad 1, a disk body unit 2, a disk cover unit 3, a disk core unit 4, a centering unit 5, a mounting base, a connecting sleeve 7, a first magnetic module 8 and a multi-channel sensor (not shown in the figure).

[0035] Further, the upper polishing pad 1 is fixedly installed below the disk body unit 2; The disk cover unit 3 is fixedly connected above the disk body unit 2, and a cavity is formed between the disk cover unit 3 and the disk body unit 2; The disk core unit 4 is wrapped in the cavity; One end of the connecting sleeve 7 is used to be fixedly connected to a mounting base, and the other end passes through the disk cover unit and is fixedly connected to the middle of the disk core unit; in the present application, the mounting base can be regarded as the disk rack 6 shown in the figure, of course, this is not restrictive; The core unit 4 includes a first magnetic module 8, and at least one of the lower surface of the cover unit 3 and the upper surface of the body unit 2 is provided with a first magnetic element for forming a magnetic cooperation with the first magnetic module 8; By controlling the magnetic pole directions of the first magnetic module 8 and / or the first magnetic element and the magnetic field strength therebetween, the magnetic force direction and magnetic force value applied by the core unit 4 to the cover unit 3 and the body unit 2 are controlled, and further the downward pressure value applied by the upper polishing disc 1 is controlled. Specifically, when the first magnetic module 8 is set as an electromagnet, the first magnetic element is set as a permanent magnet; when the first magnetic module 8 is set as a permanent magnet, the first magnetic element is set as an electromagnet; of course, it is also possible to set both the first magnetic module 8 and the first magnetic element as electromagnets. In this application, taking the first magnetic module 8 as an electromagnet and the first magnetic element as a permanent magnet as a preferred embodiment for illustration. When the first magnetic module 8 is energized, the first magnetic module 8 can generate a magnetic force. At this time, the magnetic pole formed by the first magnetic module 8 can be the same as (repulsive) or opposite to (attractive) that of the first magnetic element. When the first magnetic module 8 is not energized, the self-weights of the upper polishing disc 1, the body unit 2 and the cover unit 3 act on the wafer together, and the pressure generated thereby can be used as a reference pressure.

[0036] And the scheme of using the electromagnetic force generated by the first magnetic module 8 and the first magnetic element to adjust the pressure on the wafer has the following several schemes: Scheme 1: The first magnetic element is arranged in the cover unit 3. At this time, the first magnetic element is located above the first magnetic module 8. When the magnetic pole of the first magnetic module 8 facing the first magnetic element is the same as it, the first magnetic module 8 generates an attractive force on the first magnetic element. At this time, the electromagnetic force is downward, so that the pressure of the upper polishing disc 1 on the wafer can be increased; conversely, if the magnetic pole of the first magnetic module 8 facing the first magnetic element is different, the first magnetic module 8 generates a repulsive force on the first magnetic element. At this time, the electromagnetic force is upward, so that the pressure of the upper polishing disc 1 on the wafer can be reduced.

[0037] Scheme 2: The first magnetic element is arranged in the body unit 2. At this time, the first magnetic element is located below the first magnetic module 8. When the magnetic pole of the first magnetic module 8 facing the first magnetic element is the same as it, the first magnetic module 8 generates an attractive force on the first magnetic element. At this time, the electromagnetic force is upward, so that the pressure of the upper polishing disc 1 on the wafer can be reduced; conversely, if the magnetic pole of the first magnetic module 8 facing the first magnetic element is different, the first magnetic module 8 generates a repulsive force on the first magnetic element. At this time, the electromagnetic force is downward, so that the pressure of the upper polishing disc 1 on the wafer can be increased.

[0038] Solution 3: Set the first magnetic element into two groups. One group of the first magnetic elements is arranged on the disc cover unit 3, and the other group of the first magnetic elements is arranged on the disc body unit 2. The first magnetic module 8 is arranged vertically between the two groups of the first magnetic elements. It should be noted that the ends of the two groups of the first magnetic elements facing the first magnetic module 8 should be like magnetic poles. If it is necessary to increase the pressure of the polishing disc 1 on the wafer based on the reference pressure, make the bottom of the first magnetic module 8 and the first magnetic element in the disc body unit 2 like magnetic poles, and make the top of the first magnetic module 8 and the first magnetic element in the disc cover unit 3 unlike magnetic poles; if it is necessary to reduce the pressure of the polishing disc 1 on the wafer based on the reference pressure, make the bottom of the first magnetic module 8 and the first magnetic element in the disc body unit 2 unlike magnetic poles, and make the top of the first magnetic module 8 and the first magnetic element in the disc cover unit 3 like magnetic poles.

[0039] Refer to Figure 6 As shown, in the embodiment of the present application, Solution 3 is adopted as the optimal implementation manner. In Solution 3, the first magnetic element arranged in the disc body unit 2 is the magnetic core one 21, and the first magnetic element arranged in the disc cover unit 3 is the magnetic core two 31.

[0040] In the embodiment of the present application, the disc body unit 2 includes the magnetic core one 21 and the disc body 22, and the disc body 22 is in a round cake-shaped structure. The disc cover unit 3 includes the magnetic core two 31 and the disc cover body 33, and the disc cover body 33 is in a round cover shape.

[0041] Further, the disc body 22 is made of non-magnetic conductive material, and its specific material is not limited. Both the magnetic core one 21 and the magnetic core two 31 are arranged in multiple groups and are permanent magnets. The magnetic core one 21 is embedded on the disc body 22 and is in a structure of multiple concentric rings. The magnetic core two 31 is embedded in the cavity of the disc cover body 33 and is in a structure of multiple concentric rings.

[0042] When the first magnetic module 8 is powered on, magnetic poles are generated at the upper and lower ends. Taking the example of increasing the pressure on the wafer, the magnetic pole at the upper end of the first magnetic module 8 is magnetically opposite to the magnetic core two 31 under the disc cover unit 3 and attracts each other. The magnetic pole at the lower end of the first magnetic module 8 is magnetically the same as the magnetic core one 21 of the disc body unit 2 and repels each other. Under the magnetic force of the magnetic module one 8, the disc cover unit 3 and the disc body unit 2 are forced downward. Thus, the effect of increasing the pressure on the wafer is achieved.

[0043] Refer to Figure 7 、 Figure 8 and Figure 9 As shown, furthermore, a sealing ring 23 is provided between the circumference of the disc body 22 and the circumference of the disc cover body 33.

[0044] Refer to Figure 7 、 Figure 11 and Figure 12As shown, in the embodiment of the present application, the disk core unit 4 further includes a disk core body 42. The disk core body 42 is of a disk structure. There are multiple groups of the first magnetic modules 8, and the first magnetic modules 8 are radially distributed on the disk core body 42 with the center of the disk core body 42 as the center.

[0045] Referring to Figure 12 、 Figure 13 and Figure 14 As shown, further, the first magnetic module 8 is of an integral modular structure, including a first iron core 81, a first coil 82, an upper cover 83 and a lower cover 84.

[0046] Furthermore, the first iron core 81 is of an "I" - shaped structure, and the first coil 82 is wound around the waist of the first iron core 81. After the first coil 82 is energized, four magnetic poles are formed.

[0047] Referring to Figure 7 and Figure 10 As shown, in the embodiment of the present application, a convex sleeve is provided at the central part of the disk core unit 4. The convex sleeve of the disk core unit 4 is fixedly connected to the connecting sleeve 7, the connecting sleeve 7 is fixedly installed on the disk rack 6, the disk core unit 4 is fixed to the convex sleeve, and the centering unit 5 is assembled in the convex sleeve.

[0048] In the embodiment of the present application, the centering unit 5 includes a centering shaft 51 and an aligning bearing 52. The aligning bearing is arranged in the vertical direction. The aligning bearing 52 is sleeved on the centering shaft 51, and the inner ring of the aligning bearing 52 is fixedly connected to the centering shaft 51; the aligning bearing 52 is installed in the convex sleeve of the disk core unit 4. The inside of the convex sleeve is provided with a central hole. The outer ring of the aligning bearing 52 has a clearance fit with the central hole of the disk core unit 4, and the outer ring of the aligning bearing 52 can slide up and down in the central hole of the convex sleeve.

[0049] In the embodiment of the present application, the centering unit 5 is located above the disk body unit 2. The centering shaft 51 is fixedly connected to the disk body 22 through a screw 55. The disk body unit 2 is of a disk - shaped structure. The upper grinding and polishing disk 1 is fixedly installed below the disk body unit 2. The disk cover unit 3 is buckled on the upper part of the disk body unit 2. The disk cover unit 3 is of a circular shell - like structure. The disk cover unit 3 is fixedly connected to the disk body unit 2. The disk cover unit 3 and the disk body unit 2 form a circular cavity. The disk core unit 4 is wrapped in the circular cavity formed by the disk cover unit 3 and the disk body unit 2. There are gaps between the disk core unit 4 and the disk cover unit 3 and the disk body unit 2 both vertically and circumferentially.

[0050] The disk core unit 4 restricts two degrees of freedom of the disk body unit 2 and the disk cover unit 3 through the aligning bearing 52 and the centering shaft 51, making the disk body unit 2 and the disk cover unit 3 form a floating rotating structure.

[0051] In the embodiment of the present application, the centering unit 5 further includes a second magnetic module 53 and a third magnetic core 54. The third magnetic core 54 is installed at the top of the centering shaft 51 and is fixedly connected to the centering shaft 51. The outer ring of the third magnetic core 54 is the second magnetic module 53. The second magnetic module 53 is embedded in the convex sleeve of the disk core unit 4 through the first screw 71 and the connecting sleeve 7, and is fixedly connected to the disk core unit 4. The second magnetic module 53 and the third magnetic core 54 are a coupling pair, and there is a gap between the second magnetic module 53 and the third magnetic core 54.

[0052] Further, the second magnetic module 53 includes a second iron core and a second coil, and the third magnetic core 54 is a permanent magnet structure; when the second coil of the second magnetic module 53 is energized, a mutual force will be generated between the second magnetic module 53 and the third magnetic core 54, either upward or downward. When the magnitude or direction of the current and voltage parameters changes, the direction and magnitude of the force will also change accordingly.

[0053] Refer to Figure 7 and Figure 8 As shown, a motor rotor 32 is fixedly provided on the inner circumference of the disk cover unit 3, and a motor stator 41 is fixedly provided on the outer circumference of the disk core unit 4. The electronic rotor 32 and the motor stator 41 constitute a motor unit. Specifically, the motor stator 41 is fixedly provided around the outer wall of the disk core unit 4; the motor rotor 32 is fixedly provided around the inner wall of the disk cover unit 3, and the motor rotor 32 surrounds the outside of the motor stator 41; wherein, there is a uniform radial gap between the motor rotor 32 and the motor stator 41. When the motor stator 41 is energized, the motor rotor 32 can rotate through electromagnetic induction.

[0054] Further, the motor stator 41 includes a third iron core and a third coil, and the third coil is wound around the outer wall of the third iron core. The motor rotor 32 is a permanent magnet structure.

[0055] Refer to Figure 7 As shown, in practical applications, the motor stator 41 is connected to a driver, an inverter, or a control system through a wire. The multiple first magnetic modules 8 and the second magnetic module 53 are connected to a power supply and a control system through a wire; multiple sensors, including displacement sensors, force sensors, temperature sensors, speed sensors, current and voltage sensors, and liquid and gas pressure and flow sensors, are connected to the control system or the numerical control system through a wire or wirelessly to form a closed-loop control system. The disk core unit 4 is fixedly connected to the connecting sleeve 7 through the first screw 71, and the connecting sleeve 7 is fixedly connected to the disk rack 6 through the second screw 72. The disk rack 6 can drive the entire magnetic floating semiconductor upper grinding and polishing disk system to move up and down, or move and swing, and separate from the lower polishing disk equipment for easy loading and unloading. At the same time, before grinding and polishing, the disk rack 6 can also drive the magnetic floating semiconductor upper grinding and polishing disk system to move up and down to determine its initial position.

[0056] Both grinding and polishing are two inseparable processes in the wafer grinding process. There are various processing techniques in the grinding or polishing process. According to the requirements of the wafer processing technology, the material, shape, or structure of the upper grinding and polishing disc 1 will have different changes. The upper grinding and polishing disc 1 is fixedly installed on the disc body unit 2. The disc body unit 2, the disc cover unit 3, and the centering shaft 51 are an integrally structured fixed connection. The disc body unit 2, the disc cover unit 3, and the centering shaft 51 are centered with the disc core unit 4 through the self-aligning bearing 52. The self-aligning bearing 52 restricts two degrees of freedom of the disc body unit 2, the disc cover unit 3, and the centering shaft 51, namely their up-and-down degree of freedom and rotational degree of freedom, while there is no restriction on the two tilting degrees of freedom. Except for the connection between the centering shaft 51 and the self-aligning bearing 52, there is no contact between the disc body unit 2, the disc cover unit 3, and the disc core unit 4 and the periphery. The disc body unit 2, the disc cover unit 3, and the centering shaft 51 form a rotating and floating structure.

[0057] During operation, the upper grinding and polishing disc 1 presses on the wafer. After the motor stator 41 and the motor rotor 32 are energized, they drive the disc cover unit 3, the centering shaft 51, the disc body unit 2, and the upper grinding and polishing disc 1 to rotate together. The weights of the disc cover unit 3, the centering shaft 51, the disc body unit 2, and the upper grinding and polishing disc 1 serve as part of the pressure for grinding or polishing the wafer. When increasing the pressure on the wafer, the other part of the pressure is generated by multiple groups of the first magnetic modules 8 and the magnetic cores 21 and 31, as well as the second magnetic module 53 and the magnetic core 54.

[0058] As Figure 6 shown, when the first magnetic module 8 is energized, a magnetic field is generated. When the magnetic pole of the magnetic field generated by the first magnetic module 8 has the opposite polarity to the magnetic pole of the magnetic field of the magnetic core 31, the disc cover unit 3 is attracted and the pressure is downward. At the same time, the magnetic pole of the magnetic field generated by the first magnetic module 8 has the same polarity as the magnetic pole of the magnetic field of the magnetic core 21, and the disc body unit 2 is repelled and the pressure is also downward. At this time, the pressure borne by the wafer is the resultant force of the weights of the disc cover unit 3, the centering shaft 51, the disc body unit 2, the upper grinding and polishing disc 1 and the magnetic force generated by the first magnetic module 8. The first magnetic module 8 is a multi-group module, and the resultant force is also the resultant force of the magnetic forces of multiple groups of the first magnetic module 8. During operation, the control system can control each first magnetic module 8 in real time so that the magnetic force generated by each first magnetic module 8 changes according to the required pressure of the wafer.

[0059] The second magnetic module 53 and the magnetic core 54 can also generate magnetic forces. The second magnetic module 53 is also controlled by the control system in real time, and the magnetic force generated by it also changes according to the required pressure of the wafer. The second magnetic module 53 and the magnetic core 54 are in the central position.

[0060] In the embodiment of the present application, the upper polishing disc 1 and the disc body 22 are plastic. When the upper polishing disc 1 needs to deform, that is, when the upper polishing disc 1 needs to have a concave center or a convex center according to the requirements of the wafer processing technology, the control system can control the first magnetic module 8 and / or the second magnetic module 53, so that the first magnetic modules 8 and the second magnetic modules 53 at different positions are adjusted accordingly according to the surface shape of the wafer, and the surface shape of the upper polishing disc 1 is changed to meet the requirements.

[0061] Figure 7 , Figure 11 , Figure 12 As shown in ,

[0062] , Figure 12 , the first magnetic modules 8 are radially distributed around the center of the disc core body 42 and are arranged on the entire disc surface of the disc core body 42. The second magnetic module 53 is disposed directly above the centers of the upper polishing disc 1 and the disc body 22. When the upper polishing disc 1 needs to locally change the pressure in a partitioned manner, the control system can easily achieve this by separately controlling the first magnetic module 8 and / or the second magnetic module 53 in different regions.

[0062] In the embodiment of the present application, there are three ways to adjust the polishing surface shape of the upper polishing disc 1 according to the requirements of the target polishing process. The specific ways are as follows: Way 1: Adjust the current, voltage or their combined parameters input to each group of the first magnetic modules 8 according to the requirements to adjust the electromagnetic intensity and direction of the first magnetic modules 8; Way 2: Adjust the current, voltage or their combined parameters input to the second magnetic module 53 according to the requirements to adjust the electromagnetic intensity and direction of the second magnetic module 53, so that the centering shaft 51 drives the upper polishing disc 1 to move upward (the polishing surface shape is concave) or downward (the polishing surface shape is convex); Way 3: Adjust the current, voltage or their combined parameters input to each group of the first magnetic modules 8 and the second magnetic modules 53 according to the requirements. By jointly adjusting the first magnetic module 8 and the second magnetic module 53, different electromagnetic forces (the electromagnetic forces can be different in direction or in magnitude) are applied to different positions of the upper polishing disc 1, so that the surface shape of the upper polishing disc 1 is changed to achieve an inner concave or outer convex curved surface.

[0063] In some feasible embodiments, the upper polishing disc 1 provided in the present application can adjust the polishing surface profile of the polishing disc by adjusting the magnetic force between the first magnetic module 8 and the first magnetic core 21 and the second magnetic core 31. For example, during actual polishing, the polishing surface profile includes a flat surface, a concave-convex curved surface, and a convex-concave curved surface. To adapt to different polishing processes, the polishing end face needs to be adjusted, and the degree of concavity-convexity or convexity-concavity can be different, so as to have a variety of polishing surface profiles based on concavity-convexity or convexity-concavity. In addition, it should be noted that a concave-convex curved surface of the polishing end face means that the middle part of the polishing end face is recessed inward, and other parts form a certain inclination angle with the horizontal plane. A convex-concave curved surface of the polishing end face means that the middle part of the polishing end face protrudes outward, and other parts form a certain inclination angle with the horizontal plane.

[0064] Referring to Figure 15 As shown, the principle of adjusting the polishing surface profile by the first magnetic module 8 is as follows: ; ; ; ; Among them, is the deformation of the center of the polishing surface profile (which can be converted into the deformation of the outermost edge of the polishing surface profile), is the deformation of the polishing surface profile caused by the gravitational influence of the first magnetic module 8, is the deformation of the polishing surface profile caused by the repulsive force of the first magnetic module 8. As Figure 15 shown, is the radius of the polishing surface profile, is the distance from the farthest edge of the cross-section of the first magnetic module 8 to the center of the polishing surface profile, is the distance from the nearest edge of the cross-section of the first magnetic module 8 to the center of the polishing surface profile, is the bending stiffness, is the elastic modulus of the material, is the thickness of the disc body 22, is the Poisson's ratio of the material.

[0065] It should be specifically noted that in the present application, multiple groups of first magnetic elements are provided, and the multiple groups of first magnetic elements are in a ring structure. When calculating the change amount of the polishing surface profile, the pressure exerted by each group of first magnetic elements on the upper polishing disc 1 should be calculated separately. When calculating, refers to calculating the distance from the farthest edge of the cross-section of this group of first magnetic elements to the center of the polishing surface profile, is the distance from the nearest edge of the cross-section of this group of first magnetic elements to the center of the polishing surface profile.

[0066] Among them, the calculation method of the pressure exerted on the upper polishing pad 1 by each first magnetic element pair is as follows: ; ; ; Among them, is the pressure received by the upper polishing pad 1, is the electromagnetic force exerted on the upper polishing pad 1 by the first magnetic module 8, is the number of turns of the coil: in a coil, the more turns, the generally greater the magnetic field intensity generated, is the current: the magnitude of the current also affects the intensity of the magnetic field. The greater the current, the stronger the magnetic field; is the vacuum permeability: this is a physical constant used to describe the properties of the magnetic field in a vacuum, is the air gap thickness: in devices such as electromagnets, the air gap thickness affects the distribution of the magnetic field and the magnitude of the electromagnetic force; is the cross-sectional area of the magnetic circuit: the cross-sectional area of the magnetic circuit also affects the electromagnetic force. The larger the cross-sectional area, the greater the electromagnetic force that may be generated under the same conditions.

[0067] After considering the specification and practicing the embodiments of the present application, those skilled in the art will easily think of other implementation schemes of the present application. The present application aims to cover any variations, uses, or adaptive changes of the present application. These variations, uses, or adaptive changes follow the general principles of the present application and include the common general knowledge or conventional technical means in the technical field not claimed in the present application. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the appended claims.

Claims

1. An upper polishing pad system, characterized in that, It includes an upper grinding and polishing disc, a disc body unit, a disc cover unit, a disc core unit and a connecting sleeve; The upper grinding and polishing disc is fixedly installed below the disc body unit; The disc cover unit is fixedly connected above the disc body unit, and a cavity is formed between the disc cover unit and the disc body unit; The disc core unit is wrapped in the cavity; One end of the connecting sleeve is used to be fixedly connected to a mounting base, and the other end passes through the disc cover unit and is fixedly connected to the middle of the disc core unit; The disc core unit includes a first magnetic module, and at least one of the lower surface of the disc cover unit and the upper surface of the disc body unit is provided with a first magnetic element for forming a magnetic fit with the first magnetic module; By controlling the pole directions of the first magnetic module and / or the first magnetic element and the magnetic field strength between the two, the magnetic force direction and magnetic force value applied by the disc core unit to the disc cover unit and the disc body unit are controlled, and further the downward pressure value applied by the upper grinding and polishing disc is controlled.

2. The upper polishing pad system according to claim 1, wherein, The first pole module has upper and lower pole positions; Through control, the pole direction of the upper pole position of the first magnetic module is opposite to the pole direction of the first magnetic element on the lower surface of the disc cover unit facing the upper pole position of the first magnetic module; and / or, the pole direction of the lower pole position of the first pole module is the same as the pole direction of the first magnetic element on the upper surface of the disc body unit facing the lower pole position of the first magnetic module.

3. The upper polishing pad system according to claim 1, wherein The first pole module has upper and lower pole positions; Through control, the pole direction of the upper pole position of the first magnetic module is the same as the pole direction of the first magnetic element on the lower surface of the disc cover unit facing the upper pole position of the first magnetic module; and / or, the pole direction of the lower pole position of the first pole module is opposite to the pole direction of the first magnetic element on the upper surface of the disc body unit facing the lower pole position of the first magnetic module.

4. The upper polishing pad system according to claim 2 or 3, characterized in that, The first magnetic module is an iron core coil structure, and the first magnetic elements of the disc cover unit and the disc body unit are both permanent magnet structures, and the pole directions facing the first magnetic module are the same; By controlling the input direction of the coil current, the pole directions of the two ends of the first magnetic module are changed; by controlling the magnitude of the coil current, the magnetic force value applied by the first magnetic module to the magnet of the disc cover unit and / or the magnet of the disc body unit is changed.

5. The upper polishing pad system according to claim 4, characterized in that, The first magnetic module is an integral modular structure, including an iron core one, a coil one, an upper protective cover and a lower protective cover.

6. The upper polishing pad system according to claim 5, characterized in that, The iron core one is in an "I" - shaped structure, the coil one is wound around the waist of the iron core one, and after the coil one is energized, the iron core one forms four magnetic poles.

7. The upper polishing pad system according to claim 1, wherein The disc core unit further includes a disc core body, the first magnetic module is in multiple groups, and multiple groups of the first magnetic modules are embedded in the disc core body, and multiple groups of the first magnetic modules are radially distributed on the disc core body with the center of the disc core body as the center; The disc cover unit further includes a disc cover body, and the disc unit further includes a disc body; the first magnetic elements of the disc cover unit and / or the disc unit are multiple groups, and the multiple groups of the first magnetic elements are embedded in the lower surface of the disc cover body and / or the upper surface of the disc body, and are arranged in a plurality of concentric ring structures.

8. The upper polishing pad system according to claim 1, wherein A motor rotor is fixedly provided on the inner circumference of the disc cover unit, and a motor stator is fixedly provided on the outer circumference of the disc core unit. The motor rotor and the motor stator constitute a motor unit, and the motor unit can drive the disc cover unit and the disc unit to rotate relative to the disc core unit.

9. The upper polishing pad system according to claim 1, wherein Gaps are provided between the disc core unit and the circumferential cavity walls of the cavity formed between the lower surface of the disc cover unit, the upper surface of the disc body unit, and between the disc cover unit and the disc body unit.

10. The upper polishing pad system according to claim 7, wherein A convex sleeve is fixedly provided at the central part of the disc core unit, and the convex sleeve is fixedly connected to the connecting sleeve; A centering unit is provided in the convex sleeve. The centering unit includes a centering shaft and an aligning bearing. The centering shaft is arranged along the axis direction of the convex sleeve. The aligning bearing is sleeved on the centering shaft. The inner ring of the aligning bearing is fixed to the centering shaft, and the outer ring of the aligning bearing can slide up and down in the convex sleeve.

11. The upper polishing pad system according to claim 10, wherein, The centering unit further includes a second magnetic module and a second magnetic element. The second magnetic element is fixedly connected to the centering shaft, and the second magnetic module is fixedly connected to the disc core unit; the second magnetic module and the second magnetic element are a coupling pair, and a gap is provided between the second magnetic module and the second magnetic element.

12. The upper polishing pad system according to claim 11, wherein The second magnetic module includes a second iron core and a second coil. The second magnetic element is a permanent magnet structure. When the second coil is energized, the second magnetic module and the second magnetic element generate a mutual force. When the magnitude or direction of the current and voltage parameters during energization changes, the direction and magnitude of the force will also change accordingly.

13. The upper polishing pad system according to claim 9, wherein The disc body is made of a non-magnetic material.

14. The upper polishing pad system according to claim 7, wherein The upper polishing disc has plasticity; by adjusting the current of each group of the first magnetic modules, the magnitude and direction of the electromagnetic force between the first magnetic modules and the first magnetic elements are further adjusted, so that the polishing surface shape of the upper polishing disc is changed.

15. The upper polishing disc system according to claim 4, wherein The polishing surface shape of the upper polishing disc is obtained by the following formula: ； Wherein, is the deformation amount of the center of the polished surface profile, is the deformation amount generated by the influence of the gravitational force of the first magnetic module on the polished surface profile, is the deformation amount generated by the influence of the repulsive force of the first magnetic module on the polished surface profile of the upper grinding and polishing disc.

16. The upper polishing pad system according to claim 15, characterized in that, Calculation and The method is as follows: ； ； ； ； ； ； ； Wherein, is the radius of the polishing surface profile of the upper polishing disc, is the distance from the farthest edge of the cross-section of the first magnetic element to the center of the polishing surface profile of the upper polishing disc, is the distance from the nearest edge of the cross-section of the first magnetic element to the center of the polishing surface profile of the upper polishing disc, is the flexural rigidity, is the elastic modulus of the material, is the thickness of the disc body, is the Poisson's ratio of the material, is the pressure applied to the upper polishing disc, is the electromagnetic force applied by the first magnetic module to the upper polishing disc, is the number of turns of the coil, is the current, is the vacuum permeability, is the air gap thickness, is the cross-sectional area of the magnetic circuit.

17. The upper polishing pad system according to claim 12, wherein The upper polishing disc has plasticity; by adjusting the current of each group of the first magnetic modules and / or the second magnetic modules, the magnitude and direction of the electromagnetic force between the first magnetic modules and the first magnetic elements, and the magnitude and direction of the electromagnetic force between the second magnetic modules and the second magnetic elements are further adjusted, so that the polishing surface shape of the upper polishing disc is changed.

18. The upper polishing pad system according to claim 12, wherein The upper polishing disc has plasticity; by adjusting the current of the second magnetic module, the magnitude and direction of the electromagnetic force between the second magnetic module and the second magnetic element are further adjusted, so that the polishing surface shape of the upper polishing disc is changed.

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