Detection window, grinding gasket and chemical mechanical grinding device

Abstract

The invention provides a detection window, a grinding gasket and a chemical mechanical grinding device, the two ends of an inner frame of the detection window are arc-shaped, and the top opening of the inner frame is larger than the bottom opening of the inner frame, so that the side wall of the inner frame gradually converges inwards at a preset inclination angle to form a slope structure. According to the detection window, the grinding gasket and the chemical mechanical grinding device, the two ends of the inner frame are arranged to be arc-shaped, so that stress borne by the two ends of the inner frame can be dispersed, and therefore upheaval deformation generated by the detection window due to the action of pressure difference and transverse friction force can be weakened; the top opening of the inner frame is set to be larger than the bottom opening of the inner frame, so that the side wall of the inner frame gradually converges inwards at the preset inclination angle to form the slope structure, when the detection window is subjected to lateral friction force, a certain transverse deformation space can be provided to reduce longitudinal deformation, and therefore the protruding degree can be weakened, and the detection accuracy is improved. And the risk of detection window hole breaking can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to a detection window, a grinding pad and a chemical mechanical grinding device. Background Art

[0002] Chemical Mechanical Polishing (CMP) is the only ultra-precision processing technology that can achieve nano-scale global flattening in the processing and packaging of semiconductors and micro-electromechanical systems. The CMP process is not only an enabling process for advanced lithography and copper wire technology, but also a key step in the manufacture of integrated circuits such as chips. It has a very important impact on the performance and power consumption of chips and is an indispensable process link for the realization of advanced processes.

[0003] See also Figure 1 and Figure 2 , Figure 1 It is a structural schematic diagram of a chemical mechanical polishing device in the prior art; Figure 2 for Figure 1 The schematic diagram of the structure of the monitoring window installed on the grinding pad is shown. Figure 1 and Figure 2 It can be seen that the chemical mechanical polishing equipment includes a polishing table 10, a polishing pad 11 disposed on the polishing table 10, and a polishing head 13 disposed above the polishing pad 11; a monitoring window 12 for monitoring the polishing state of a wafer 14 is installed on the polishing pad 11. When the wafer 14 is subjected to chemical mechanical polishing, the back side of the wafer 14 is adsorbed on the bottom of the polishing head 13, and the front side of the wafer 14 is attached to the polishing pad 11. The chemical mechanical polishing equipment realizes the flattening of the wafer surface by combining chemical etching and mechanical polishing.

[0004] However, during the process of grinding the wafer 14, the monitoring window 12 may occasionally have a hole phenomenon. After the monitoring window 12 has a hole phenomenon, if the wafer 14 is continued to be ground, it will affect the machine process parameter capture and wafer morphology, and the thickness control and planarization requirements required by the CMP process cannot be achieved, which will bring high risks to subsequent processes and wafer yield. Summary of the invention

[0005] The purpose of the present invention is to provide a detection window, a polishing pad and a chemical mechanical polishing device to solve one or more problems in the prior art, such as occasional holes in the monitoring window affecting the machine process parameter capture and wafer morphology.

[0006] To achieve the above-mentioned purpose, the present invention is implemented through the following technical scheme: a detection window is arranged in a grinding pad, both ends of the inner frame of the detection window are arc-shaped, and the top opening of the inner frame is larger than the bottom opening of the inner frame, so that the side wall of the inner frame gradually converges inward at a preset inclination angle to form a slope structure.

[0007] Optionally, the orthographic projection of the inner frame on the plane where the grinding pad is located is in a racetrack ring shape.

[0008] Optionally, the orthographic projection of the inner frame on the plane where the grinding pad is located is an elliptical ring.

[0009] Optionally, an orthographic projection of the top of the inner frame on the plane where the grinding pad is located and an orthographic projection of the bottom of the inner frame on the plane where the grinding pad is located are co-centered.

[0010] Optionally, the preset tilt angle has a value range of 15 degrees to 30 degrees.

[0011] Optionally, the detection window is made of light-transmitting material.

[0012] In order to achieve the above object, the present invention further provides a grinding pad, in which any one of the above detection windows is provided.

[0013] Optionally, the upper surface of the grinding pad is coplanar with the upper surface of the detection window.

[0014] Optionally, at least two detection windows are provided in the grinding pad.

[0015] To achieve the above object, the present invention further provides a chemical mechanical polishing device, comprising any one of the detection windows described above or any one of the polishing pads described above.

[0016] Compared with the prior art, the detection window, the polishing pad and the chemical mechanical polishing device provided by the present invention have the following beneficial effects:

[0017] The detection window provided by the present invention is arranged in a grinding pad, and both ends of the inner frame of the detection window are arc-shaped, and the top opening of the inner frame is larger than the bottom opening of the inner frame, so that the side wall of the inner frame gradually converges inward at a preset tilt angle to form a slope structure. Therefore, the detection window provided by the present invention, by setting the two ends of the inner frame into an arc shape, the stress on the two ends of the inner frame can be dispersed, thereby reducing the bulge deformation of the detection window due to the pressure difference and the lateral friction force. Further, by setting the top opening of the inner frame to be larger than the bottom opening of the inner frame so that the side wall of the inner frame gradually converges inward at a preset tilt angle to form a slope structure, it can provide a certain lateral deformation space to reduce the longitudinal deformation when the detection window is subjected to lateral friction, thereby reducing the degree of bulge, and further reducing the risk of holes in the detection window.

[0018] Since the grinding pad provided by the present invention and the chemical mechanical grinding device provided by the present invention belong to the same inventive concept as the detection window provided by the present invention, the grinding pad provided by the present invention and the chemical mechanical grinding device provided by the present invention at least have all the advantages of the detection window provided by the present invention. For the advantages of the grinding pad provided by the present invention and the chemical mechanical grinding device provided by the present invention, please refer to the relevant description of the beneficial effects of the detection window provided by the present invention, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a chemical mechanical polishing device in the prior art;

[0020] Figure 2 for Figure 1 A schematic diagram of the structure of a monitoring window installed on the polishing pad shown;

[0021] Figure 3 It is a structural schematic diagram of a monitoring window in the prior art;

[0022] Figure 4 for Figure 3 A schematic side cutaway view of the monitoring window shown;

[0023] Figure 5 for Figure 3 One of the specific example diagrams of the monitoring window when it is subjected to force and bulges;

[0024] Figure 6 A specific example diagram of a detection window provided in the first embodiment of the present invention;

[0025] Figure 7 for Figure 6 A schematic side cut of the detection window shown;

[0026] Figure 8Another specific example diagram of a detection window provided in the first embodiment of the present invention;

[0027] Fig. 9 for Figure 8 A schematic side cut of the detection window shown;

[0028] The following are the descriptions of the reference numerals:

[0029] 10-grinding table, 11-grinding pad, 12-monitoring window, 121-lining, 13-grinding head, 14-wafer, 20-detection window, 201-inner frame. DETAILED DESCRIPTION

[0030] The detection window, polishing pad and chemical mechanical polishing device proposed by the present invention are further described in detail below in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change of the proportional relationship or adjustment of the size, under the same or similar conditions as the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. And, in the embodiments described below, sometimes the same figure mark is used in common between different drawings to represent the same part or part with the same function, and its repeated description is omitted.

[0031] In order to make it easier to understand and explain the present invention, before describing the specific implementation methods of the detection window, polishing pad and chemical mechanical polishing device provided by the present invention, the research process of proposing the present invention is briefly described as follows.

[0032] Please continue to see Figure 1 and Figure 2First, the inventor of the present invention analyzed the reasons for the occasional hole phenomenon in the monitoring window 12. By observing the grinding process of the wafer 14, the inventor found that the monitoring window 12 would be continuously subjected to lateral friction and extrusion during the grinding process, and friction would generate heat. The monitoring window 12 is located below a closed space, which causes the gas in the monitoring window 12 to expand due to heat and generate an internal and external pressure difference, thereby generating an outward bulging force. As the grinding pad 11 is consumed and becomes thinner, at the end of the consumable life cycle of the grinding pad 11, the monitoring window 12 will occasionally have holes under the combined effect of the friction, extrusion, and the outward bulging force generated in the monitoring window 12.

[0033] In order to solve this problem, the inventor first thought of cooling the monitoring window 12, but considering that the grinding table 10 has integrated cooling water pipelines for physical cooling of the grinding pad 11, if the monitoring window 12 is cooled by circulating air, it will increase the design cost, purchase cost, use cost and later maintenance cost. Then, the inventor thought of looking for a grinding pad 11 made of superior wear-resistant material, but this will increase the cost of machine inspection and time cost.

[0034] For further information, see Figures 3 to 5 , Figure 3 It is a structural schematic diagram of a monitoring window in the prior art; Figure 4 for Figure 3 A schematic side cutaway view of the monitoring window shown; Figure 5 for Figure 3 The monitoring window shown is one of the specific examples when it is subjected to force and bulges. Figures 3 to 5 It can be seen that the inner lining 121 of the monitoring window 12 is rectangular. After a lot of research and continuous in-depth practice, the inventors found that the four corners of the rectangular inner lining 121 are susceptible to concentrated stress, which can easily cause the monitoring window 12 to bulge and produce holes.

[0035] After optimization and improvement, for example, the inner lining 121 of the monitoring window 12 is designed to have an elliptical or rounded rectangular outer edge, so that the pressure can be evenly distributed at each point of the arc, which can effectively reduce the risk of window breaking.

[0036] Based on the above research, the core idea of ​​the present invention is to solve the technical problems existing in the prior art, such as occasional holes in the monitoring window, which affect the capture of machine process parameters and wafer morphology.

[0037] In order to realize the above idea, the present invention provides a detection window, a polishing pad and a chemical mechanical polishing device, which optimize the structure of the monitoring window to solve one or more problems such as occasional holes in the existing monitoring window affecting the capture of machine process parameters and wafer morphology.

[0038] Next, the specific embodiments of the detection window, the polishing pad and the chemical mechanical polishing device provided by the present invention are described in detail as follows.

[0039] Embodiment 1

[0040] This embodiment provides a detection window, which is set in the grinding pad (not shown in the figure). Figure 6 and Figure 7 , Figure 6 A specific example diagram of a detection window provided in this embodiment;

[0041] Figure 7 for Figure 6 A schematic diagram of the side cut of the detection window shown. Figure 6 and Figure 7 It can be seen that both ends of the inner frame 201 of the detection window 20 are arc-shaped, and the top opening of the inner frame 201 is larger than the bottom opening of the inner frame 201, so that the side wall of the inner frame 201 gradually converges inward at a preset tilt angle to form a slope structure. Therefore, the detection window provided in this embodiment, by setting the two ends of the inner frame 201 to be arc-shaped, the stress on the two ends of the inner frame 201 can be dispersed, thereby reducing the bulge deformation of the detection window 20 due to the pressure difference and the lateral friction force. Further, by setting the top opening of the inner frame 201 to be larger than the bottom opening of the inner frame 201 so that the side wall of the inner frame 201 gradually converges inward at a preset tilt angle to form a slope structure, it can provide a certain lateral deformation space to reduce the longitudinal deformation when the detection window 20 is subjected to lateral friction, thereby reducing the degree of bulge, and further reducing the risk of holes in the detection window 20.

[0042] Please continue to see Figure 6 and Figure 7 For example, in some exemplary embodiments, the orthographic projection of the inner frame 201 on the plane where the grinding pad is located is in the shape of a racetrack ring.

[0043] It should be noted that, as those skilled in the art can understand, the above is merely an exemplary description of the inner frame 201 , rather than a limitation of the present invention.

[0044] For example, see Figure 8 and Fig. 9 , Figure 8 Another specific example diagram of the detection window provided in this embodiment; Fig. 9 for Figure 8 A schematic diagram of the side cut of the detection window shown. Figure 8 and Fig. 9It can be seen that in some other embodiments, the orthographic projection of the inner frame 201 on the plane where the grinding pad is located may also be in the form of an elliptical ring.

[0045] For more information, please see Figures 6 to 9 ,like Figures 6 to 9 As shown, the orthographic projection of the top of the inner frame 201 on the plane where the grinding pad is located and the orthographic projection of the bottom of the inner frame 201 on the plane where the grinding pad is located are co-centered.

[0046] It should be noted that the present invention does not impose too many restrictions on the specific value of the preset tilt angle, and the specific value of the preset tilt angle can be set according to the actual application scenario. For example, in some embodiments, the value range of the preset tilt angle includes 15 degrees to 30 degrees; in other embodiments, the preset tilt angle can also be 45 degrees; in still other embodiments, the preset tilt angle can also be 60 degrees.

[0047] Preferably, the detection window 20 is made of a light-transmitting material, thereby being able to monitor the state of the surface of the wafer 14 in real time, thereby being able to accurately determine the end point of grinding, and being helpful in improving production efficiency and product quality.

[0048] Embodiment 2

[0049] This embodiment provides a polishing pad, in which the detection window 20 described in any of the above embodiments is provided.

[0050] Since the grinding pad provided in this embodiment and the detection window 20 provided in any of the above-mentioned embodiments belong to the same inventive concept, the grinding pad provided in this embodiment has at least all the advantages of the detection window 20 provided in the above-mentioned embodiments. For the advantages of the grinding pad provided in this embodiment, please refer to the relevant description of the beneficial effects of the detection window 20 provided in the above-mentioned embodiments, which will not be repeated here.

[0051] Preferably, the upper surface of the grinding pad is coplanar with the upper surface of the detection window 20. Thus, by making the grinding pad coplanar with the upper surface of the detection window 20, it is possible to ensure that uniform pressure is applied to the entire grinding area, thereby improving the quality and consistency of grinding.

[0052] Furthermore, the grinding pad is provided with at least two detection windows 20. Thus, by providing a plurality of detection windows 20 in the grinding pad, the state of the wafer 14 can be monitored at different positions simultaneously, which helps to more comprehensively understand the removal of the material on the surface of the entire wafer 14, thereby improving the accuracy and reliability of the detection results.

[0053] Embodiment 3

[0054] This embodiment provides a chemical mechanical polishing device, including the detection window 20 described in any of the above embodiments or the polishing pad described in any of the above embodiments.

[0055] Since the chemical mechanical polishing device provided in this embodiment and the detection window 20 provided in any of the above-mentioned embodiments or the polishing pad provided in any of the above-mentioned embodiments belong to the same inventive concept, the chemical mechanical polishing device provided in this embodiment has at least all the advantages of the detection window 20 or the polishing pad provided in the above-mentioned embodiments. For the advantages of the chemical mechanical polishing device provided in this embodiment, please refer to the relevant description of the beneficial effects of the detection window 20 or the polishing pad provided in the above-mentioned embodiments, which will not be repeated here.

[0056] In summary, the detection window, grinding pad and chemical mechanical grinding device provided by the present invention have the following advantages: the detection window provided by the present invention is arranged in the grinding pad, the two ends of the inner frame of the detection window are arc-shaped, and the top opening of the inner frame is larger than the bottom opening of the inner frame, so that the side wall of the inner frame gradually converges inward at a preset tilt angle to form a slope structure. Therefore, the detection window provided by the present invention, by setting the two ends of the inner frame into an arc shape, the stress on the two ends of the inner frame can be dispersed, thereby reducing the bulge deformation of the detection window due to the pressure difference and the lateral friction force. Further, by setting the top opening of the inner frame to be larger than the bottom opening of the inner frame, the side wall of the inner frame gradually converges inward at a preset tilt angle to form a slope structure, which can provide a certain lateral deformation space to reduce the longitudinal deformation when the detection window is subjected to lateral friction, thereby reducing the degree of bulge, and further reducing the risk of hole in the detection window.

[0057] Since the grinding pad provided by the present invention and the chemical mechanical grinding device provided by the present invention belong to the same inventive concept as the detection window provided by the present invention, the grinding pad provided by the present invention and the chemical mechanical grinding device provided by the present invention at least have all the advantages of the detection window provided by the present invention. For the advantages of the grinding pad provided by the present invention and the chemical mechanical grinding device provided by the present invention, please refer to the relevant description of the beneficial effects of the detection window provided by the present invention, which will not be repeated here.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A detection window, arranged in a grinding pad, characterized in that: Both ends of the inner frame of the detection window are arc-shaped, and the top opening of the inner frame is larger than the bottom opening of the inner frame, so that the side wall of the inner frame gradually converges inward at a preset inclination angle to form a slope structure.

2. The detection window according to claim 1, characterized in that: The orthographic projection of the inner frame on the plane where the grinding pad is located is in a racetrack ring shape.

3. The detection window according to claim 1, characterized in that: The orthographic projection of the inner frame on the plane where the grinding pad is located is an elliptical ring.

4. The detection window according to claim 1, characterized in that: The orthographic projection of the top of the inner frame on the plane where the grinding pad is located is co-centered with the orthographic projection of the bottom of the inner frame on the plane where the grinding pad is located.

5. The detection window according to claim 1, characterized in that: The preset tilt angle has a value range of 15 degrees to 30 degrees.

6. The detection window according to claim 1, characterized in that: The detection window is made of light-transmitting material.

7. A polishing pad, characterized in that: The polishing pad is provided with a detection window as claimed in any one of claims 1 to 6.

8. The polishing pad according to claim 7, wherein: The upper surface of the grinding pad is coplanar with the upper surface of the detection window.

9. The polishing pad according to claim 7, wherein: At least two detection windows are arranged in the grinding pad.

10. A chemical mechanical polishing device, characterized in that: The method comprises the detection window as claimed in any one of claims 1 to 6 or the polishing pad as claimed in any one of claims 7 to 9.

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