Pressure control components, grinding equipment, chemical mechanical polishing machine.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NEXCHIP SEMICON CO LTD
- Filing Date
- 2025-05-29
- Publication Date
- 2026-05-26
Smart Images
Figure CN224274587U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of wafer polishing technology, and in particular to pressure control components, polishing apparatus, and chemical mechanical polishing machines. Background Technology
[0002] Chemical mechanical polishing (CMP) is one of the key processes in the semiconductor manufacturing industry. CMP equipment includes polishing heads, polishing discs, and polishing pads adhered to the polishing discs. Currently, common polishing head structures include pressure diaphragms and retaining rings.
[0003] During grinding, the grinding head vacuum-adsorbs and fixes the wafer, the positioning ring covers the edge area of the wafer, and the pressure film is divided into multiple pressure zones with concentric circles along different diameters. By adjusting the pressure value in different zones, together with the positioning ring, the wafer is pressed and rotated relative to the surface of the grinding pad, so that mechanical friction is formed between its surface and the grinding pad. Through a series of chemical reactions and mechanical actions, the wafer surface is planarized and polished.
[0004] Therefore, improving the pressure control of the grinding head is crucial for enhancing the efficiency and accuracy of the CMP process, and is a key area for future research and development in this field. Utility Model Content
[0005] Therefore, it is necessary to provide a pressure control component, a grinding device, and a chemical mechanical polishing machine to address the problems mentioned in the background art, which can at least improve the efficiency and accuracy of the CMP process.
[0006] To address the aforementioned technical problems and other issues, according to some embodiments, one aspect of this application provides a pressure control assembly for mounting on a grinding head, the pressure control assembly comprising:
[0007] The pressure membrane has a pressure surface including a central region and multiple annular pressure zones surrounding the central region. The center point of the central region and the center points of the multiple annular pressure zones are arranged sequentially along the radial direction of the pressure surface.
[0008] A positioning ring, which circumferentially surrounds the pressure membrane and is located on the periphery of the pressure membrane, includes multiple positioning parts distributed at intervals along the circumferential direction;
[0009] The controller, connected to the grinding head, controls the pressure diaphragm and positioning ring to perform corresponding actions, so that the pressure values of the positioning part, the central area and the annular pressure zone are the same or different, in order to match the target pattern on the wafer surface.
[0010] In the pressure control component of the above embodiment, the redesign and adjustment of the pressure area of the pressure film (i.e., the central area and multiple annular pressure areas) can better match the target pattern on the wafer surface, reducing the difference in grinding amount in the same radius grinding area caused by the difference in film thickness; the original integrated positioning ring is replaced with a segmented positioning ring with multiple positioning parts, which individually controls the pressure of the wafer edge and prevents the edge from being over-grinded.
[0011] In some embodiments, the center point of the central region and the center points of the multiple annular pressure zones are arranged sequentially along a radial direction close to the center of the pressure surface.
[0012] In the pressure control component of the above embodiment, the pressure film is divided into multiple non-concentric asymmetric pressure regions, which enables pressure regions with the same radius to have different pressure values, thereby more flexibly responding to the pressure value applied to the target pattern on the wafer surface.
[0013] In some embodiments, the positioning ring is ring-shaped;
[0014] Multiple positioning parts have the same target size; the target size is used to characterize the circumferential dimension of a positioning part.
[0015] In some embodiments, the central angle range corresponding to the target size of a positioning part is 36°~72°.
[0016] In the pressure control assembly of the above embodiment, a segmented annular positioning ring circumferentially surrounds the pressure membrane and applies pressure to the edge of the wafer. The independent positioning parts can each apply the same or different pressure values and cooperate with the pressure membrane to form the target pattern of the wafer.
[0017] In some embodiments, the outer contours of the central region and the annular pressure zone do not overlap.
[0018] In some embodiments, the pressure membrane includes at least four annular pressure zones.
[0019] In some embodiments, the center point of at least one annular pressure zone overlaps with the geometric center of the positioning ring.
[0020] In the pressure control component of the above embodiment, by setting an equal number of annular pressure zones and ensuring that the corresponding pressure zones do not overlap, the occurrence of pressure superposition or confusion caused by the intersection of zones can be avoided.
[0021] Another aspect of this application provides a grinding apparatus, including the pressure control component described in any of the above embodiments.
[0022] In some embodiments, the grinding apparatus further includes: a grinding disc;
[0023] A sensor, located within the polishing pad, communicates with the controller to detect the wafer surface pattern and generate a feedback signal after the polishing head picks up the wafer.
[0024] In the polishing apparatus of the above embodiments, the polishing head equipped with the pressure control component of the above embodiments, after adsorbing the wafer, applies differential pressure to polishing areas with different film thicknesses according to the target pattern on the wafer surface, demonstrating good process adaptability.
[0025] Another aspect of this application provides a chemical mechanical polishing machine, including the pressure control component described in any of the above embodiments; or the grinding apparatus described in the above embodiments.
[0026] The pressure control components, grinding apparatus, and chemical mechanical polishing machine provided in this application have the following unexpected technical effects:
[0027] By redesigning and adjusting the pressure zone of the pressure film (i.e., the central area and multiple annular pressure zones), the traditional concentric annular pressure zone within the pressure surface is replaced with a pressure film having asymmetric annular pressure zones; the original integrated positioning ring is also replaced with a segmented positioning ring with multiple positioning parts, allowing for individual control of the wafer edge pressure and preventing excessive edge grinding.
[0028] When the polishing head applies pressure to the wafer, it causes a significant difference in pressure distribution at the same radius, breaking the symmetry of pressure transmission in traditional pressure films. At the same time, with the help of advanced sensors, the wafer surface pattern is accurately identified, and the pressure is adjusted for different positions on the edge or for the corresponding wafer surface pattern and film thickness differences, so as to meet the polishing amount required for each part.
[0029] The above structures work together to achieve high-precision grinding of the wafer, meeting the stringent requirements of semiconductor manufacturing for wafer processing precision and improving the accuracy and yield of chip manufacturing. Attached Figure Description
[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.
[0031] Figure 1 This is a schematic diagram of the structure of a pressure control component in the prior art;
[0032] Figure 2 This is a schematic diagram of the structure of a grinding head in the prior art;
[0033] Figure 3This is a schematic diagram of the structure of a pressure control component provided in one embodiment of this application;
[0034] Figure 4 This is a schematic diagram of a pressure membrane provided in one embodiment of this application;
[0035] Figure 5 This is a schematic diagram of a positioning ring provided in one embodiment of this application;
[0036] Figure 6 A schematic diagram of the cross-sectional profile of the wafer film thickness obtained by grinding traditional pressure control components;
[0037] Figure 7 A schematic diagram of the cross-sectional profile of the wafer film thickness obtained by grinding using the pressure control components provided in this application.
[0038] Explanation of reference numerals in the attached figures:
[0039] 10. Pressure membrane; 11. Central region; 12. Annular pressure zone; 121. First annular pressure zone; 122. Second annular pressure zone; 123. Third annular pressure zone; 124. Fourth annular pressure zone; 20. Positioning ring; 21. Positioning part; 30. Controller. Detailed Implementation
[0040] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.
[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0042] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.
[0043] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.
[0044] In this application, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal connection of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0045] Figure 1 This is an example diagram of the structure of a pressure control assembly in the prior art, including a concentric annular pressure diaphragm that divides pressure zones along different diameters (e.g., 80 mm, 200 mm, 260 mm, 290 mm, and 299 mm), and a positioning ring surrounding the edge of the pressure diaphragm. Please refer to [link / reference]. Figure 2 The grinding head is equipped with a gas channel. When the gas channel is evacuated to generate negative pressure, the wafer is adsorbed and fixed. When the gas is vented to generate positive pressure, the pressure film deforms and adheres tightly to the wafer and presses it onto the surface of the grinding pad, thereby performing grinding.
[0046] Because of the design patterns on the wafer surface, the film thickness in different areas often varies depending on functional requirements. However, such as Figure 2 As shown, the positioning ring, as a whole, can only apply the same pressure P to the wafer edge within its annular region. RR Only the same pressure P can be applied within an annular pressure zone of the same radius under the pressure membrane. M For example, the pressure is P5 in the 80mm pressure zone; P4 in the 200mm annular pressure zone; P3 in the 260mm annular pressure zone; P2 in the 290mm annular pressure zone; and P1 in the 299mm annular pressure zone. Therefore, it is impossible to adjust the pressure according to different positions on the edge or the corresponding wafer surface patterns and film thickness differences to meet the required grinding amount for each part. Some areas are prone to over- or under-grinding, making it difficult to guarantee the uniformity of the morphology.
[0047] Based on this, please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a pressure control component provided in one embodiment of this application. The pressure control component provided in this embodiment includes: a pressure diaphragm 10, the pressure surface of which includes a central region 11 and a plurality of annular pressure zones 12 surrounding the central region 11, the center point of the central region 11 and the center points of the plurality of annular pressure zones 12 being arranged sequentially along the radial direction of the pressure surface;
[0048] The positioning ring 20 surrounds the pressure membrane 10 circumferentially and is located on the periphery of the pressure membrane 10, and includes a plurality of positioning parts 21 distributed at intervals along the circumferential direction.
[0049] The controller 30, connected to the grinding head, is used to control the pressure diaphragm 10 and the positioning ring 20 to perform corresponding actions, so that the pressure values of the positioning part 21, the central region 11 and the annular pressure area 12 are the same or different, so as to match the target pattern on the wafer surface.
[0050] Please see Figure 1 and Figure 3 In this embodiment, the traditional concentric annular pressure region is replaced with a pressure film 10 with an asymmetric annular pressure region. The pressure values of the central region 11 and the annular pressure region 12 can be set according to the target pattern on the wafer surface and different film thickness regions.
[0051] For example, the material of the pressure membrane includes, but is not limited to, flexible materials such as liquid silicone or rubber.
[0052] It should be noted that, for ease of understanding this application, Figure 3 This is a schematic diagram of an exemplary pressure control component provided in an embodiment of this application. Other suitable examples of the pressure control component provided in this application are also possible, and no limitations are imposed here.
[0053] In some embodiments, the center point of the central region 11 and the center points of the plurality of annular pressure zones 12 are arranged sequentially along a radial direction close to the center of the pressure surface;
[0054] In an optional embodiment, the pressure membrane 10 includes at least four annular pressure zones 12.
[0055] In an optional embodiment, the outer contours of the central region 11 and the annular pressure region 12 do not overlap.
[0056] Please see Figure 4 For example, D represents the diameter of the pressure surface; the annular pressure zone 12 includes a first annular pressure zone 121, a second annular pressure zone 122, a third annular pressure zone 123 and a fourth annular pressure zone 124.
[0057] For example, the diameter of the central region 11 can be 78mm-83mm, such as 78mm, 80mm and 83mm; the corresponding applied pressure is P5.
[0058] The outer diameter of the first annular pressure zone 121 can be 293mm-300mm, for example, 293mm, 297mm and 300mm; the corresponding applied pressure is P1.
[0059] The outer diameter of the second annular pressure zone 122 can be 284mm-293mm, for example, 284mm, 290mm and 293mm; the corresponding applied pressure is P2.
[0060] The outer diameter of the third annular pressure zone 123 can be 254mm-284mm, for example, 254mm, 268mm and 284mm; the corresponding applied pressure is P3.
[0061] The outer diameter of the fourth annular pressure zone 124 can be 83mm-254mm, for example, 83mm, 150mm and 254mm; the corresponding applied pressure is P4.
[0062] It should be understood that the outer contours of the central region 11 and the annular pressure region 12 do not overlap; the outer contours of the first annular pressure region 121, the second annular pressure region 122, the third annular pressure region 123, and the fourth annular pressure region 124 should also not overlap. For example, when the outer contour diameter of the first annular pressure region 121 is 293 mm, the outer contour diameter of the second annular pressure region 122 is 292.5 mm or other values less than 293 mm, and the outer contour relationships of other annular pressure regions are deduced accordingly.
[0063] Specifically, when the grinding head applies pressure to the wafer, such as Figure 4 As shown, the pressure values within the same annular pressure zone 12 are the same. Since the center point of the central region 11 within the pressure surface and the center points of multiple annular pressure zones 12 are arranged sequentially along the radial direction close to the center of the pressure surface, there is a significant difference in the pressure distribution on the left and right sides of the pressure surface symmetry line at the same radius position, which breaks the symmetry of traditional pressure membrane pressure transmission.
[0064] Furthermore, by adjusting the pressure applied to the central region 11 or any annular pressure zone 12 via the controller 30, the local polishing rate of the wafer can be controlled. When a larger pressure is applied to the annular pressure zone corresponding to a certain side, the polishing amount on that side of the wafer will increase significantly; conversely, if a smaller pressure is applied, the polishing amount on the corresponding side will decrease accordingly. For example, during the process of adjusting the film thickness of a specific area on the wafer surface, if it is found that the film thickness in a certain local area of the wafer is too thick and requires more polishing, the pressure in the annular pressure zone 12 corresponding to that area can be appropriately increased to increase the polishing amount of this part of the wafer, so as to achieve the ideal film thickness standard. This method of flexibly and accurately controlling the local polishing rate according to the actual situation of the wafer greatly improves the accuracy of wafer polishing and helps to ensure the uniformity of the polishing amount on the wafer surface.
[0065] In some embodiments, the positioning ring 20 is annular; the target size of the plurality of positioning portions 21 is the same; the target size is used to characterize the circumferential size of a positioning portion.
[0066] In an alternative embodiment, at least one center point of the annular pressure zone 12 overlaps with the geometric center of the positioning ring 20.
[0067] In an optional embodiment, the central angle range corresponding to the target size of a positioning part 21 is 36° to 72°.
[0068] Please see Figure 5 For example, L represents the length of the arc formed by the line connecting the two ends of the positioning part, which is the target size. In fact, the positioning ring 20 can be divided into multiple positioning parts 21 at equal angles (i.e., all target sizes are the same), or it can adopt an unequal division scheme with some parts having the same angle and some parts having different angles (i.e., some target sizes are the same and some are different).
[0069] In this embodiment, the positioning ring 20 has a ring-shaped structure, and the target size L of each positioning part 21 on it is the same. This design feature provides a fundamental guarantee for the precise positioning of the wafer. Since all positioning parts 21 have the same target size L, when circumferentially surrounding the edge of the wafer, each positioning part 21 can act on the edge of the wafer with a uniform dimensional standard, ensuring that the positioning force on the edge of the wafer is evenly distributed when it is positioned. For example, when the wafer is placed inside the positioning ring 20, each positioning part 21 applies stable and balanced pressure to the corresponding part of the wafer edge according to the same target size L, avoiding uneven pressure caused by differences in the size of the positioning parts 21, thereby effectively reducing deviations such as displacement and tilting of the wafer during the positioning process and improving the positioning accuracy of the wafer in subsequent processing steps.
[0070] For example, the central angle range corresponding to the target size of a positioning part 21 is 36° to 72°, such as 36°, 40°, 45°, 60°, and 72°. In this embodiment, the central angle of the positioning part 21 is 45°.
[0071] Please see Figures 6-7 , Figure 6 This is a schematic diagram of the cross-sectional profile of a wafer obtained by grinding a traditional pressure control component. Figure 7 This is a schematic diagram of the cross-sectional profile of a wafer obtained by grinding using the pressure control component provided in this application. The horizontal axis represents the wafer diameter in millimeters (mm), and the vertical axis represents the wafer film thickness after grinding in angstroms (Å). According to the schematic diagram of the wafer film thickness after grinding, the wafer morphology uniformity is better after processing with the pressure control component provided in this application compared to traditional grinding equipment.
[0072] In some embodiments, this disclosure also provides a grinding apparatus, including: a grinding disc;
[0073] A sensor, located within the polishing pad, communicates with the controller to detect the wafer surface pattern and generate a feedback signal after the polishing head picks up the wafer.
[0074] Among them, the sensor is a high-precision white light real-time feedback sensor.
[0075] Specifically, the polishing pad has holes that serve as sensor detection windows, through which the sensor's detection surface detects the wafer surface to be polished.
[0076] As an example, the working principle of the grinding device proposed in this application embodiment is as follows:
[0077] Before performing the grinding operation, the wafer surface with the target pattern is flipped face down, facing the detection window of the grinding pad. After the grinding head equipped with the pressure control component picks up the wafer, the sensor detects the pattern on the wafer surface and generates a feedback signal. After receiving the feedback signal, the controller can apply pressure to areas with different film thicknesses according to the target pattern on the wafer surface.
[0078] Throughout the grinding process, the sensor continuously monitors the film thickness in each area in real time, and the data is quickly fed back to the controller to achieve differentiated pressure application in a short period of time; the pressure membrane 10 is responsible for precisely controlling the grinding pressure and determining the amount of grinding in different areas of the wafer; the positioning ring 20 ensures the stability of wafer positioning and provides a good foundation for grinding.
[0079] In some embodiments, this disclosure also provides a chemical mechanical polishing (CMP) machine. Based on this polishing apparatus, the CMP machine can use advanced sensors to monitor and identify wafer surface patterns in real time, quickly determining the film thickness in each area. Its pressure control component can intelligently and differentially adjust the pressure of the polishing head based on this information. When applying pressure to polishing areas with different film thicknesses, it can accurately match the required pressure for each area, avoiding damage to the pattern, ensuring pattern integrity, and improving the precision and yield of chip manufacturing.
[0080] Please note that the above embodiments are for illustrative purposes only and do not imply any limitation on the present invention.
[0081] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0083] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A pressure control component, characterized in that, For mounting on a grinding head, the pressure control assembly includes: The pressure membrane has a pressure surface including a central region and a plurality of annular pressure zones surrounding the central region, wherein the center point of the central region and the center points of the plurality of annular pressure zones are arranged sequentially along the radial direction of the pressure surface. A positioning ring, which circumferentially surrounds the pressure membrane and is located on the periphery of the pressure membrane, includes a plurality of positioning portions spaced apart along the circumferential direction; The controller, connected to the grinding head, is used to control the pressure diaphragm and the positioning ring to perform corresponding actions, so that the pressure values of the positioning part, the central region and the annular pressure zone are the same or different, so as to match the target pattern on the wafer surface.
2. The pressure control component according to claim 1, characterized in that, The center point of the central region and the center points of the plurality of annular pressure zones are arranged sequentially along the radial direction close to the center of the pressure surface.
3. The pressure control component according to claim 2, characterized in that, The positioning ring is ring-shaped; The target dimensions of the plurality of positioning parts are the same; the target dimensions are used to characterize the circumferential dimension of one of the positioning parts.
4. The pressure control component according to claim 3, characterized in that, The central angle range corresponding to the target size of the positioning part is 36°~72°.
5. The pressure control component according to any one of claims 1-4, characterized in that, The outer contours of the central region and the annular pressure zone do not overlap.
6. The pressure control component according to any one of claims 1-4, characterized in that, The pressure membrane includes at least four of the aforementioned annular pressure zones.
7. The pressure control assembly according to any one of claims 1-4, characterized in that, The center point of at least one of the annular pressure zones overlaps with the geometric center of the positioning ring.
8. A grinding apparatus, characterized in that, Includes the pressure control component as described in any one of claims 1-7.
9. The grinding apparatus according to claim 8, characterized in that, Also includes: Grinding disc; A sensor, disposed within the polishing pad, communicates with the controller and is used to detect the surface pattern of the wafer and generate a feedback signal after the polishing head adsorbs the wafer.
10. A chemical mechanical polishing machine, characterized in that, Includes the pressure control component as described in any one of claims 1-7; or The grinding apparatus according to any one of claims 8-9.