Polishing retaining ring and chemical mechanical polishing equipment
By designing grooves and detection slots on the grinding retaining ring, the life of the retaining ring can be accurately determined, solving the problem of life uncertainty in the prior art and improving the quality and efficiency of chemical mechanical grinding.
Patent Information
- Application Number
- CN202520095880.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-15
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2035-01-15
AI Technical Summary
Existing technologies cannot accurately determine the lifespan of the grinding retainer ring, leading to errors and risks during the grinding process, which affects the quality and efficiency of chemical mechanical grinding.
The grinding retaining ring is designed with multiple grooves and detection grooves. The grooves are used to evenly distribute the grinding fluid, and the detection grooves are used to determine the wear and tear of the retaining ring by the number of grooves that disappear, so as to accurately determine its lifespan.
By detecting the number of grooves, the wear and tear of the retaining ring can be determined, reducing wear and deformation caused by the expiration of its lifespan, improving the accuracy and uniformity of the grinding process, and reducing maintenance costs and time.
Smart Images
Figure CN223685132U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to mechanical chemical polishing equipment field, concretely relates to a kind of grinding retaining ring and chemical mechanical polishing equipment. BACKGROUND
[0002] In chemical mechanical polishing machine, the retaining ring on the polishing head is a very important component in the polishing process. The retaining ring is usually an annular structure, which surrounds the area where the polishing pad contacts the wafer. The material of the retaining ring generally has certain hardness and wear resistance, and the common ones are engineering plastics or metal materials. The different service life of the grinding ring is crucial to the process, but because the consumption of the grinding ring depends on various factors such as polishing time, polishing head pressure, polishing pad material and polishing liquid type, it is not possible to accurately determine the remaining life of the grinding retaining ring. At present, only through time and product piece number information can the life of the grinding retaining ring be indirectly grasped, which has a large error and certain risk.
[0003] It should be noted that the information disclosed in the above background section is only used to enhance the understanding of the background of the utility model, and therefore can include information that does not constitute prior art known to those skilled in the art. CONTENT OF THE UTILITY MODEL
[0004] In view of the problems in the prior art, the purpose of the utility model is to provide a grinding retaining ring and a chemical mechanical polishing equipment. The grinding retaining ring can accurately determine the life of the grinding retaining ring by detecting the number of detection grooves on its grinding surface, which helps to take measures such as replacing the grinding retaining ring in advance, and improves the quality and efficiency of chemical mechanical polishing.
[0005] The first aspect of the utility model provides a grinding retaining ring, which comprises an annular body;
[0006] The annular body has an inner peripheral wall, an outer peripheral wall and a grinding surface of one end face;
[0007] The grinding surface is provided with a plurality of grooves and a plurality of detection grooves;
[0008] Any of the grooves extends from the inner peripheral wall of the annular body to the outer peripheral wall of the annular body and penetrates through;
[0009] Any of the detection grooves extends from the inner peripheral wall of the annular body to the outer peripheral wall of the annular body and penetrates through, and the depths of at least two detection grooves in the axial direction of the annular body are different.
[0010] According to the first aspect of the utility model, a plurality of grooves are uniformly distributed in the circumferential direction of the grinding surface, and a detection groove is arranged between two adjacent grooves; and / or
[0011] The plurality of detection grooves are uniformly distributed in the circumferential direction of the grinding surface.
[0012] According to the first aspect of the utility model, the width of the section of the detection groove in the plane perpendicular to the axial direction of the annular body is w, the width of the section of the groove in the plane perpendicular to the axial direction of the annular body is W, and w≤1 / 2W is satisfied.
[0013] According to the first aspect of the utility model, the depths of the detection grooves in the axial direction of the annular body are all different.
[0014] According to the first aspect of the utility model, the maximum depth of the plurality of detection grooves in the axial direction of the annular body is tmax, the depth of the groove in the axial direction of the annular body is T, and (T-tmax)≥0.2mm is satisfied.
[0015] According to the first aspect of the utility model, the depths of the plurality of detection grooves in the axial direction of the annular body increase or decrease successively.
[0016] According to the first aspect of the utility model, the two detection grooves with the same depth in the axial direction of the annular body are symmetrically arranged relative to the axis of the annular body.
[0017] According to the first aspect of the utility model, the depths of the plurality of detection grooves in the axial direction of the annular body form an arithmetic sequence, and / or
[0018] The common difference of the arithmetic sequence is between 0.1 and 0.3mm.
[0019] According to the first aspect of the utility model, the grinding retaining ring further comprises a buffer pad, and the buffer pad is arranged on the inner circumferential wall of the annular body.
[0020] The second aspect of the utility model provides a chemical mechanical grinding equipment comprising the grinding retaining ring.
[0021] The grinding retaining ring of the utility model is provided with detection grooves with different depths, and the consumption condition or residual service life of the retaining ring is directly determined by the number of remaining detection grooves after grinding, which reduces the problems such as unstable fixing of wafers in the grinding process due to wear and deformation of the retaining ring due to expiration of the service life in the chemical mechanical grinding process, and further affects the precision and uniformity of chemical mechanical grinding. BRIEF DESCRIPTION OF DRAWINGS
[0022] Other features, objects and advantages of the utility model will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings.
[0023] Other features, objects and advantages of the utility model will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings.Figure 1 FIG. 1 is a structural schematic view of a grinding surface of a grinding retaining ring according to an embodiment of the present application;
[0024] Figure 2 FIG. 2 is a cross-sectional view of the grinding surface of the grinding retaining ring according to the embodiment of the present application; and
[0025] Figure 3 FIG. 3 is a structural schematic view of a grinding surface of a grinding retaining ring according to another embodiment of the present application. DETAILED DESCRIPTION
[0026] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein. Rather, these implementations are provided as example embodiments so that this disclosure will be thorough and complete, and will fully convey the scope thereof to those skilled in the art. Embodiments described below are examples only, and are not intended to limit the present application in any way. Same reference numerals in different drawings identify same or similar elements, and explicit descriptions of these similar elements will not be repeated.
[0027] In the description of the present application, it is to be understood that the terms "first", "second", "third" and the like, merely identify features being referred to and do not imply or imply relative importance or a number of the features. Thus, a feature with a "first", "second", "third" attribute can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.
[0028] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements or the interaction between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0029] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.
[0030] The structure of the grinding retaining ring and the chemical mechanical grinding equipment of the present application will be further described below in combination with the drawings and specific embodiments. It can be understood that each specific embodiment is not a limitation on the protection scope of the present application.
[0031] The present application provides a grinding retaining ring, which is a key component in the chemical mechanical grinding (CMP) process. In the chemical mechanical grinding process, the grinding retaining ring is used to fix the wafer and stably keep the wafer at a specific position below the grinding head, preventing the wafer from shifting or shaking during the grinding process, and ensuring the precision and uniformity of the grinding.
[0032] Specifically, the grinding retaining ring includes a ring-shaped body; the ring-shaped body has an inner peripheral wall, an outer peripheral wall, and a grinding surface of one end face, the inner peripheral wall of the ring-shaped body needs to be matched with the outer diameter of the wafer to be fixed, the outer peripheral wall of the ring-shaped body cooperates with other parts of the chemical mechanical grinding equipment, and the grinding surface interacts with the polishing pad during the grinding process.
[0033] Figure 1 The structure of the grinding surface of the grinding retaining ring of an embodiment of the present application is shown in the figure, the grinding surface is provided with a plurality of grooves 11 and a plurality of detection grooves, each groove 11 extends from the inner peripheral wall of the ring-shaped body to the outer peripheral wall of the ring-shaped body and penetrates, in the chemical mechanical grinding process, the grinding liquid is transported to the interface between the polishing pad and the wafer through these grooves 11, so that the grinding liquid can fully participate in the grinding process, improve the uniformity of the wafer grinding rate, and help to realize more accurate material removal and better surface quality control. Preferably, the plurality of grooves 11 are uniformly distributed in the circumferential direction of the grinding surface. The number of grooves 11 can be determined according to the size of the wafer to be fixed.
[0034] The width of the section of the trench 11 in the plane perpendicular to the axial direction of the annular body can be consistent or inconsistent. The trench 11 can be a strip-shaped through groove or an arc-shaped through groove. Taking the section of the trench 11 as a strip-shaped through groove and the section of the through groove as a rectangle as an example, the width of the section of the trench 11 in the plane perpendicular to the axial direction of the annular body is W, and the depth of the trench in the axial direction of the annular body is T. The width W of the trench has an important influence on the flow and distribution of the polishing liquid. If the width W is too narrow, the polishing liquid cannot enter the wafer area, resulting in a low polishing rate. If the width W is too wide, the polishing liquid may be gathered at the edge of the wafer, resulting in over-polishing of the wafer edge and affecting the flatness of the wafer surface. The trench with a large depth T can accommodate more polishing liquid, but may affect the structural strength of the retaining ring. The trench with a small depth T may not provide sufficient polishing liquid storage and flow space, affecting the polishing effect.
[0035] The polishing surface of the polishing retaining ring is provided with a plurality of detection grooves extending from the inner circumferential wall of the annular body to the outer circumferential wall of the annular body and penetrating through, and the depths of at least two detection grooves in the axial direction of the annular body are different. Figure 1 In the embodiment, the polishing surface is provided with N detection grooves, which are a first detection groove 121, a second detection groove 122, a third detection groove 123, an i-th detection groove 12i, and an N-th detection groove 12N. If one detection groove is arranged between two adjacent trenches 11, the number of trenches 11 of the polishing surface is also N. The N detection grooves can also be uniformly distributed in the circumferential direction of the polishing surface.
[0036] The width of the section of the detection groove 12i in the plane perpendicular to the axial direction of the annular body can be consistent or inconsistent. The detection groove 12i can be a strip-shaped through groove or an arc-shaped through groove. Taking the section of the detection groove as a strip-shaped through groove and the section of the through groove as a rectangle as an example, the width of the section of the i-th detection groove 12i in the plane perpendicular to the axial direction of the annular body is wi, and the depth of the i-th detection groove 12i in the axial direction of the annular body is ti. In the utility model, the width w of any one detection groove is less than or equal to 1 / 2W, and W is the width of the section of the trench in the plane perpendicular to the axial direction of the annular body. Preferably, the width wi of the detection groove 12i is about 1 / 3 of the width W of the trench 11.
[0037] Figure 2In a sectional view of the grinding surface of the grinding retaining ring in a clockwise (CW) direction in an embodiment of the present application, the depths of the detection grooves in the axial direction of the annular body are all different. In this embodiment, the depths of the detection grooves in the axial direction of the annular body can be sequentially increased or decreased, for example, in the clockwise CW direction of the grinding surface, the depths of the first detection groove 121, the second detection groove 122, the third detection groove 123, the i-th detection groove 12i, and the N-th detection groove 12N are sequentially decreased, preferably, the depths of the detection grooves in the axial direction of the annular body form an arithmetic sequence, and the common difference of the arithmetic sequence is between 0.1 and 0.3 mm.
[0038] For example, if the grinding retaining ring has 8 (N) detection grooves, such as the groove 11, and the depth W is 2.2 mm, then the depths of the first detection groove 121, the second detection groove 122, the third detection groove 123, the i-th detection groove 12i, and the eighth detection groove 128 are sequentially decreased, and are respectively 2.0 mm, 1.8 mm, 1.6 mm, …, 0.6 mm.
[0039] When the grinding retaining ring of the present application is used to clamp a wafer for chemical mechanical grinding, the grinding surface of the grinding retaining ring is worn out with the number of grinding, and the detection grooves with different depths disappear in turn, wherein the detection groove with the smallest depth in the plurality of detection grooves disappears first, when the depths of the plurality of detection grooves in the clockwise CW direction are sequentially decreased or increased, the plurality of detection grooves gradually disappear in the counterclockwise or clockwise direction, and the operator can estimate the wear of the grinding surface by observing the number of detection grooves on the grinding surface of the grinding retaining ring, when all the detection grooves disappear, it can be considered that the grinding surface of the grinding retaining ring is worn out and needs to be replaced. In order to set the detection grooves to well warn the life limit of the grinding retaining ring, preferably, the maximum depth of the detection grooves in the axial direction of the annular body is tmax, and the depth of the groove in the axial direction of the annular body is T, and satisfies: (T-tmax)≥0.2 mm. In the above embodiment, T is 2.2 mm, and tmax is t1 of the first detection groove 121.
[0040] The grinding retaining ring of the present application can accurately determine the service life of the grinding retaining ring by detecting the number of detection grooves on the grinding surface, which helps to predict possible failures in advance, so that appropriate measures can be taken to avoid downtime of the grinding equipment or damage to other parts of the equipment due to failure of the grinding retaining ring, thereby reducing maintenance cost and maintenance time and improving production efficiency.
[0041] It should be noted that the plurality of grooves 11 and the plurality of detection grooves can extend along the normal line (ON / ON') of the polishing surface, and the grooves and the detection grooves can be arranged according to the rotation direction of the polishing retaining ring relative to the polishing pad during polishing. For example, the extension direction of the grooves 11 can form an angle α with the normal line ON of the normal polishing surface, and the extension direction of the detection grooves can form an angle β with the normal line ON of the normal polishing surface, and both α and β are not zero degrees.
[0042] In some embodiments, the annular polishing surface can be divided into a plurality of sector regions, and the depths of the plurality of detection grooves in each region are sequentially increased or decreased.
[0043] In some other embodiments, two detection grooves with the same depth along the axis direction of the annular body are symmetrically arranged relative to the axis OO' of the annular body.
[0044] Figure 3 The structure diagram of the polishing surface of the polishing retaining ring of another embodiment of the utility model is shown, wherein the extension line of the diameter of the polishing surface is DD', and DD' divides the polishing surface into two semicircular regions. For example, four detection grooves, i.e., the first detection groove 131, the second detection groove 132, the third detection groove 133, and the fourth detection groove 134, are arranged in one semicircular region, and four detection grooves, i.e., the first detection groove 131', the second detection groove 132', the third detection groove 133', and the fourth detection groove 134', are arranged in the other semicircular region. The depths of the first detection groove 131, the first detection groove 131', the second detection groove 132, the second detection groove 132', the third detection groove 133, the third detection groove 133', the fourth detection groove 134, and the fourth detection groove 134' are the same, respectively, and are symmetric about the axis OO' of the annular body. Similarly, the depths of the first detection groove 131, the second detection groove 132, the third detection groove 133, and the fourth detection groove 134 can be sequentially increased or decreased, and the depths of the first detection groove 131', the second detection groove 132', the third detection groove 133', and the fourth detection groove 134' can be sequentially increased or decreased. The two detection grooves with the same depth symmetrically arranged relative to the axis OO' of the annular body can determine whether the two detection grooves with the same depth disappear at the same time during polishing, so as to detect whether the polishing retaining ring is tilted during polishing, reduce the uneven distribution of polishing pressure caused by the tilt of the polishing retaining ring, and make the force on the wafer inconsistent during polishing, thereby causing uneven polishing of the wafer surface and affecting the flatness and roughness of the wafer.
[0045] In some other embodiments, the two detection grooves of the two semi-circular regions have the same depth, and the two detection grooves are symmetrical with respect to the diameter DD' of the grinding surface, at this time, the depths of the first detection groove 131, the second detection groove 132, the third detection groove 133 and the fourth detection groove 134 can be increased (decreased) in turn, and the depths of the first detection groove 131', the second detection groove 132', the third detection groove 133' and the fourth detection groove 134' are decreased (increased) in turn.
[0046] The utility model also provides a kind of chemical mechanical grinding equipment, including grinding retaining ring.The chemical mechanical grinding equipment usually also includes grinding head, grinding pad, polishing liquid supply unit and driving unit, polishing liquid supply unit transmits polishing liquid to grinding pad, grinding retaining ring stably clamps wafer and keeps wafer at the specific position below grinding head, driving unit drives grinding head to move relative to grinding pad with certain pressure, make wafer surface and grinding pad and the friction of polishing liquid thereon, to realize the effect of grinding polishing.Grinding retaining ring can also include buffer pad being arranged in the inner circumferential wall of its annular body, the thickness of buffer pad can be between 0.03mm to 0.08mm.Buffer pad can prevent wafer and grinding retaining ring from colliding or rubbing directly, avoid wafer edge damage, ensure the integrity and quality of wafer;Meanwhile, it is helpful to absorb vibration generated during grinding, so that wafer keeps relatively stable state, to improve the precision and flatness of grinding, reduce the problem such as uneven grinding caused by vibration.The chemical mechanical grinding equipment of the utility model can improve the machining precision of mechanical chemical grinding, improve the consistency of product.
[0047] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the utility model, and those skilled in the art can change, modify, replace and modify the above-mentioned embodiments within the scope of the utility model.
[0048] The above content is further detailed description of the utility model in combination with specific preferred embodiments, and the specific implementation of the utility model cannot be limited to these descriptions.For those skilled in the art to which the utility model belongs, without departing from the concept of the utility model, a number of simple deductions or replacements can be made, which should be regarded as belonging to the protection scope of the utility model.
Claims
1. A polishing retainer ring characterized by, The annular body comprises an inner peripheral wall, an outer peripheral wall, and a grinding surface of an end surface; The grinding surface is provided with a plurality of grooves and a plurality of detection grooves; Any one of the grooves extends from the inner peripheral wall of the annular body to the outer peripheral wall of the annular body and penetrates through; Any one of the detection grooves extends from the inner peripheral wall of the annular body to the outer peripheral wall of the annular body and penetrates through, and the depths of at least two of the detection grooves in the axial direction of the annular body are different. The plurality of grooves are uniformly distributed in the circumferential direction of the grinding surface, and one detection groove is arranged between any two adjacent grooves; and / or 2. The polishing retainer ring of claim 1, wherein, The plurality of detection grooves are uniformly distributed in the circumferential direction of the grinding surface. The width of the cross section of the detection groove in the plane perpendicular to the axial direction of the annular body is w, and the width of the cross section of the groove in the plane perpendicular to the axial direction of the annular body is W, satisfying: w≤1 / 2W.
3. The polishing retainer ring of claim 1, wherein, The depths of each of the detection grooves in the axial direction of the annular body are different.
4. The polishing retainer ring of claim 1, wherein, The maximum depth of the plurality of detection grooves in the axial direction of the annular body is tmax, and the depth of the groove in the axial direction of the annular body is T, satisfying: (T-tmax)≥0.2mm.
5. The polishing retainer ring of claim 1, wherein, The depths of the plurality of detection grooves in the axial direction of the annular body increase or decrease in turn.
6. The polishing retainer ring of claim 1, wherein, Two detection grooves with the same depth in the axial direction of the annular body are symmetrically arranged with respect to the axis of the annular body.
7. The polishing retainer ring of claim 1, wherein The depths of the plurality of detection grooves in the axial direction of the annular body form an arithmetic sequence, and / or 8. The polishing retainer ring of claim 1, wherein, The common difference of the arithmetic sequence is between 0.1 and 0.3mm. Further comprising a buffer pad arranged on the inner peripheral wall of the annular body.
9. The polishing retainer ring of claim 1, wherein, The grinding retaining ring comprises the annular body according to any one of claims 1 to 9.
10. A chemical mechanical polishing apparatus characterized by comprising: