Protective device, chemical mechanical polishing system and polishing method

Abstract

The invention discloses a protection device, a chemical mechanical polishing system and a polishing method.The protection device is used for protecting a polishing disc in the chemical mechanical polishing system and comprises an annular main body part located on the peripheral side of the polishing disc; the main body part comprises an accommodating cavity which is arranged in the main body part and is used for storing liquid; the liquid outlet is formed in the inner side of the main body piece and communicates with the containing cavity; and liquid in the accommodating cavity flows to the inner side wall of the main body piece through the liquid outlet, so that the inner side wall of the main body piece is moisturized.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor manufacturing technology, and in particular to a protective device, a chemical mechanical polishing system, and a polishing method. Background Art

[0002] The integrated circuit industry is the core of the information technology industry and plays a key role in promoting the transformation and upgrading of the manufacturing industry towards digitalization and intelligence. Chips are the carriers of integrated circuits, and chip manufacturing involves process flows such as integrated circuit design, wafer manufacturing, wafer processing, electrical measurement, cutting packaging and testing. Among them, chemical mechanical polishing is one of the five core processes in the wafer manufacturing process.

[0003] Chemical Mechanical Polishing (CMP) is an ultra-precision surface processing technology for global flattening. Chemical mechanical polishing usually involves sucking the wafer onto the bottom surface of a carrier head, with the side of the wafer with the deposition layer abutting against the upper surface of the polishing pad. The carrier head rotates in the same direction as the polishing pad under the actuation of the drive assembly and applies a downward load to the wafer; the polishing liquid is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the wafer completes the chemical mechanical polishing of the wafer under the combined action of chemistry and mechanics.

[0004] During the polishing process, the polishing disc rotates at a certain speed, and the polishing waste liquid and cleaning water on the surface of the polishing pad will be thrown outward under the action of centrifugal force. In order to control the impact of the polishing waste liquid on the polishing unit, an annular retaining ring is usually set on the outer peripheral side of the polishing disc to block the thrown liquid to a certain extent.

[0005] Although most of the waste liquid splashed toward the retaining ring is discharged with the cleaning water, a small amount of polishing waste liquid still remains on the inner wall of the retaining ring; this small amount of polishing waste liquid will adhere to the inner wall of the retaining ring and form crystals, and these crystals will fall on the surface of the polishing pad due to external vibration during the up and down movement of the retaining ring. The crystals falling on the surface of the polishing pad will bring the risk of scratching the wafer, thereby affecting the yield rate of wafer manufacturing.

[0006] To ensure the reliable operation of the chemical mechanical polishing system, the inner wall of the retaining ring needs to be cleaned manually regularly. However, due to the limited operating space inside the polishing unit, this will affect the efficiency of the retaining ring cleaning and thus the operating time of the CMP system. Summary of the invention

[0007] In view of this, embodiments of the present application provide a protective device, a chemical mechanical polishing system and a polishing method to at least partially solve the above problems.

[0008] According to a first aspect of an embodiment of the present application, a protection device is provided for protecting a polishing disk in a chemical mechanical polishing system, the protection device comprising an annular main body and located on the outer peripheral side of the polishing disk; the main body comprises:

[0009] The accommodating cavity is arranged inside the main body and is used for caching liquid;

[0010] A liquid outlet, which is arranged on the inner side of the main body and communicates with the accommodating cavity;

[0011] The liquid in the accommodating cavity flows to the inner side wall of the main body through the liquid outlet to achieve moisturizing of the inner side wall of the main body.

[0012] In some embodiments, the liquid outlet is disposed at the top and / or the inner upper edge of the main body, so that the liquid flowing out of the liquid outlet covers the splashing area of ​​the polishing waste liquid centrifugally thrown out by the polishing disk.

[0013] In some embodiments, there are multiple liquid outlets, which are arranged at intervals along the circumference of the main body.

[0014] In some embodiments, the top surface of the main body is inclined toward the inside.

[0015] In some embodiments, the inner upper edge of the main body is in an arc transition, so that the liquid flowing out of the liquid outlet flows smoothly toward the inner wall of the main body through the inner upper edge.

[0016] In some embodiments, the top surface of the main body is configured with an annular opening facing inward, and the liquid flowing out of the liquid outlet flows toward the inner wall of the main body through the annular opening.

[0017] In some embodiments, the liquid outlet located at the top of the main body is inclined upward and inward.

[0018] In some embodiments, the liquid outlet located at the top of the main body is arranged vertically upward, and the liquid outlet is located at the corner of the annular opening.

[0019] In some embodiments, the liquid outlet located at the inner upper edge of the main body is inclined upward and inward.

[0020] In some embodiments, the protective device also includes an outer cover plate, which is matched with the main body to form the accommodating cavity; the outer cover plate is configured with a liquid inlet, which is connected to an external liquid source to transport the liquid to the accommodating cavity.

[0021] In some embodiments, the main body is configured with an annular groove, and the outer cover is arranged on the outside of the annular groove to form the accommodating cavity.

[0022] In some embodiments, the liquid inlet is arranged at a height less than or equal to a height of the liquid outlet.

[0023] In some embodiments, the main body is made of homopolymer polypropylene, polyphenylene sulfide or polyetheretherketone.

[0024] In some embodiments, the surface roughness Ra value of the inner wall of the main body is ≥6.3 μm.

[0025] According to the second aspect of the embodiment of the present application, a chemical mechanical polishing system is provided, characterized in that it includes a polishing disk, a carrying head, a liquid supply device and a trimming device, the carrying head presses the wafer to be polished against the polishing pad above the polishing disk, the liquid supply device supplies polishing liquid between the polishing pad and the wafer, and the trimming device is used to trim the surface of the polishing pad; it also includes the protective device mentioned above to achieve moisturizing of the inner side wall of the main body to prevent crystallization on the inner side wall of the main body.

[0026] According to the third aspect of an embodiment of the present application, a polishing method is provided, in which polishing is performed in the chemical mechanical polishing system described above. During the chemical mechanical polishing process, the liquid in the containing cavity of the main body flows to the inner wall of the main body through the liquid outlet to achieve moisturizing of the inner wall of the main body.

[0027] The beneficial effects of the present invention include:

[0028] a. The protective device provided is equipped with a main body with a receiving cavity, and the liquid in the receiving cavity flows to the inner wall of the main body through the liquid outlet by overflow. This moisturizing method is relatively gentle, so as to prevent the contaminants on the inner wall of the main body from moving toward the direction of the polishing disc, thereby preventing the contaminants from moving back and forth between the polishing disc and the main body to increase the cleaning cost;

[0029] b. The protective device is provided with an outer cover plate, which is detachably arranged on the outer peripheral side of the main body, and the outer cover plate is provided with a liquid inlet to temporarily store the liquid in the accommodating cavity; the height of the liquid inlet is less than or equal to the height of the liquid outlet, so that the liquid stored in the accommodating cavity overflows from the inner side wall of the main body through the liquid outlet, thereby forming a relatively complete water film on the inner side wall of the main body, thereby achieving a good moisturizing effect;

[0030] c. There are multiple liquid outlets, which are arranged at intervals along the circumference of the main body, so that the liquid overflowing from the liquid outlet can cover the entire area of ​​the main body, thereby preventing polishing contaminants from remaining on the inner side wall of the main body and forming crystals;

[0031] d. The liquid outlet is arranged at the inner upper edge of the main body, and the liquid outlet is arranged to be inclined upward and inward; the liquid in the accommodating cavity is discharged outward through the inclined liquid outlet, and the liquid needs to overcome a certain resistance before being discharged from the liquid outlet, which reduces the speed of the liquid to a certain extent, and prevents the liquid flowing out of the liquid outlet from spraying in the reverse direction toward the polishing disc, thereby facilitating the liquid to form a water film on the inner wall of the main body to achieve good moisturizing;

[0032] e. The liquid outlet is provided at the top of the main body, and the liquid in the accommodating cavity flows out through the liquid outlet, thereby covering the splashing area of ​​the polishing waste liquid centrifugally thrown out by the polishing disk to prevent crystallization from forming on the inner side wall of the main body;

[0033] f. The inner upper edge of the main body is arc-shaped so that the liquid flowing out of the liquid outlet flows smoothly to the inner wall of the main body through the inner upper edge, so as to control the influence of the angular structure of the main body on the movement of the fluid and avoid the damage of the formed liquid film by the newly inflowing liquid;

[0034] g. The liquid outlet is a long hole, which is arranged along the circumference of the main body; the liquid in the accommodating cavity slowly overflows through the liquid outlet to form a complete water film on the inner wall of the main body;

[0035] h. The top surface of the main body is provided with an annular opening facing inward, and the liquid outlet is arranged at the corner of the annular opening. The liquid flowing out of the liquid outlet flows to the inner wall of the main body through the annular opening. At the same time, the overflowed liquid can moisturize the side wall of the annular opening, thereby preventing the polishing contaminants from forming crystals in this area. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0037] Figure 1 is a longitudinal cross-sectional view of a protective device provided in an embodiment of the present application;

[0038] Figure 2 is a partial schematic diagram of a protective device provided by an embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of an embodiment of the present invention providing a main body member with an inclined liquid outlet on its inner upper edge;

[0040] Figure 4 is a schematic diagram of a main body provided in an embodiment of the present invention having a vertical liquid outlet disposed on the top;

[0041] Figure 5 is a schematic diagram of a main body provided in an embodiment of the present invention having an annular opening disposed on the top;

[0042] Figure 6 is a schematic diagram of a main body provided by an embodiment of the present invention, in which the top is inclined and a vertical liquid outlet is configured;

[0043] Figure 7 is a schematic diagram of an inclined liquid outlet disposed on the top of a main body provided by an embodiment of the present invention;

[0044] Figure 8 is a schematic diagram of a protective device provided by another embodiment of the present invention;

[0045] Fig. 9 Schematic diagram of a chemical mechanical polishing system provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the embodiments of the present application should fall within the scope of protection of the embodiments of the present application.

[0047] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0048] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0049] Figure 1 is a longitudinal cross-sectional view of a protective device 100 provided in one embodiment of the present invention, the protective device 100 is used for Fig. 9The protection device 100 of the polishing disc 200 in the chemical mechanical polishing system 1000 is shown. Specifically, the protection device 100 includes a main body 10, which is an annular structure and is arranged on the outer peripheral side of the polishing disc to block the polishing waste liquid centrifugally ejected from the upper side of the polishing disc 200, and inhibit the polishing waste liquid from spreading outward and contaminating other areas.

[0050] Specifically, a polishing pad is arranged on the upper side of the polishing disk, and the polishing liquid is supplied between the wafer and the polishing pad. The wafer pressed against the surface of the polishing pad completes chemical mechanical polishing under the action of chemical and mechanical factors to remove the material on the surface of the wafer. After polishing, deionized water (DIW) is supplied toward the surface of the polishing pad to clean the pollutants remaining on the surface of the polishing pad. These pollutants and deionized water will be thrown off to the inner wall of the main body 10 under the action of centrifugal force and guided to the waste liquid outlet under the action of gravity.

[0051] Usually, deionized water will rinse the inner wall of the main body 10, thereby removing most of the polishing contaminants; however, a small amount of contaminants are not removed in time and form crystals. If the crystals formed on the inner wall of the main body 10 fall onto the surface of the polishing pad, the polished wafer may come into contact with the crystals and be scratched, thereby reducing the yield rate of the wafer.

[0052] To solve the above problems, the protective device 100 provided by the present invention not only has the function of blocking polishing waste liquid, but also has the function of moisturizing, so that the inner wall of the main body 10 is always in an infiltrated state, thereby preventing pollutants from drying and crystallizing on the inner wall of the main body 10.

[0053] Specifically, Figure 1 The main body 10 shown includes:

[0054] The accommodating chamber 11 is disposed inside the main body 10 and is used to buffer the liquid;

[0055] The liquid outlet 12 is arranged on the inner side of the main body 10, and the liquid outlet 12 is connected to the accommodating cavity 11; specifically, the liquid outlet 12 extends from the inner wall of the accommodating cavity 11 to the inner wall of the main body 10; the liquid in the accommodating cavity 11 flows to the inner wall of the main body 10 through the liquid outlet 12 to achieve moisturizing of the inner wall of the main body 10.

[0056] It should be noted that, in the present invention, in the longitudinal cross-sectional view of the main body 10, "inside" and "outside" are relative to the polishing disk; the side of the main body 10 close to the polishing disk is called the "inside", and the side of the main body 10 away from the polishing disk is called the "outside".

[0057] The moisturizing method of the inner wall of the main body 10 provided by the present invention is relatively gentle. Specifically, the liquid for moisturizing is stored in the accommodating chamber 11, and the liquid is continuously supplied to the accommodating chamber 11; when the liquid level in the accommodating chamber 11 is higher than the liquid outlet 12, the liquid will overflow from the liquid outlet 12 under the action of gravity, so that the liquid infiltrates the inner wall of the main body 10, thereby achieving moisturizing of the inner wall of the main body 10.

[0058] Compared with the traditional spray moisturizing method, the above moisturizing method is relatively gentle, so as to prevent the contaminants on the inner wall of the main body 10 from moving toward the polishing disk, thereby preventing the contaminants from moving back and forth between the polishing disk and the main body 10 to increase the cleaning cost.

[0059] It should be noted that the liquid buffered in the accommodating cavity 11 may be deionized water (DIW) and / or a cleaning liquid with a cleaning effect, etc., so as to maintain the cleanliness of the inner wall of the main body 10 while retaining moisture.

[0060] Figure 1 In the illustrated embodiment, the protection device 100 further includes an outer cover plate 20 , which is matched with the main body 10 to enclose and form a receiving cavity 11 .

[0061] Furthermore, the outer cover plate 20 is provided with a liquid inlet 21 , which is connected to an external liquid source (not shown) to continuously deliver the liquid into the accommodating cavity 11 at a certain pressure and flow rate.

[0062] Furthermore, the main body 10 is provided with Figure 2 The annular groove 11 a is shown, and the outer cover plate 20 is disposed on the outer side of the annular groove 11 a to form the accommodating cavity 11 .

[0063] In some embodiments, the height of the liquid inlet 21 is less than or equal to the height of the liquid outlet 12, so that the liquid stored in the accommodating cavity 11 overflows to the inner wall of the main body 10 through the liquid outlet 21, thereby forming a relatively complete water film on the inner wall of the main body 10, thereby achieving a good moisturizing effect.

[0064] Figure 1 In the illustrated embodiment, if the height of the liquid outlet 12 is greater than the height of the liquid inlet 21, the liquid may flow directly from the liquid inlet 21 to the liquid outlet 12, so that the liquid flowing out of the liquid outlet 12 has a certain speed, which is not conducive to the formation of a water film on the inner wall of the main body 10. At the same time, the polishing contaminants on the inner wall of the main body 10 may be pushed to the location of the polishing disk to cause a secondary pollution problem.

[0065] Figure 2It is a partial schematic diagram of a protective device 100 provided in one embodiment of the present invention. There are multiple liquid outlets 12, which are arranged at intervals along the circumference of the main body 10, so that the liquid overflowing from the liquid outlet 12 can cover the entire area of ​​the main body 10, thereby preventing polishing contaminants from remaining on the inner wall of the main body 10 and forming crystals.

[0066] It is understandable that the distance between adjacent liquid outlets 12 may be 3-10 mm, so that the overflowing liquid can cover the inner wall of the main body 10 .

[0067] Figure 1 and Figure 2 In the illustrated embodiment, the liquid outlet 12 is disposed at the inner upper edge of the main body 10, that is, the liquid outlet 12 is located on the inner side of the main body 10 and close to the top of the main body 10, and the liquid overflowing from the liquid outlet 12 covers the inner wall of the main body 10 as much as possible, so that the liquid flowing out of the liquid outlet 12 covers the splashing area of ​​the polishing waste liquid centrifugally thrown out by the polishing disk.

[0068] It should be noted that the main body 10 of the protective device 100 can be moved vertically. Fig. 9 As shown, the protection device 100 can move up and down in the vertical direction to cooperate with the interaction between the carrier head and the loading cup and prevent the polishing waste liquid from being thrown out without restriction. The interaction process between the carrier head and the loading cup can be referred to the description in patent CN113118965A.

[0069] Specifically, when the carrier head moves between the polishing plate and the loading platform, the main body 10 needs to move downward to prevent the main body 10 from interfering with the movement of the carrier head; at this time, the CMP system does not perform a polishing operation and does not generate polishing waste liquid.

[0070] When the carrier head loads the wafer from the loading and unloading platform and moves to the top of the polishing disk, the main body 10 moves toward the upper side so that the main body 10 blocks the polishing waste liquid thrown out by centrifugation to prevent the polishing waste liquid from contaminating other areas of the polishing unit. It should be noted that the top of the main body 10 moved to the upper side needs to be higher than the horizontal plane of the polishing pad on the upper side of the polishing disk, so that the polishing waste liquid is thrown to the middle and upper area of ​​the main body 10. Therefore, the liquid outlet 12 is set at the inner upper edge of the main body 10, so that the middle and upper area of ​​the main body 10 is always in a moisturizing state, thereby preventing the polishing waste liquid from forming crystals on the inner wall of the main body 10 and causing wafer scratch defects.

[0071] Figure 3 yes Figure 1 A variation of the embodiment shown is shown. In this embodiment, the liquid outlet 12 is located at the inner upper edge of the main body 10, and the liquid outlet 12 is inclined upward and inward.

[0072] With such arrangement, the liquid in the accommodating cavity 11 is discharged outwardly through the inclined liquid outlet 12; since the liquid outlet 12 is arranged inclined, the liquid needs to overcome a certain resistance before being discharged from the liquid outlet 12, which reduces the speed of the liquid to a certain extent, and avoids the liquid flowing out of the liquid outlet 12 from being sprayed in the opposite direction toward the polishing disk, which is beneficial for the liquid to form a water film on the inner wall of the main body 10 to achieve good moisturizing.

[0073] In some embodiments, the angle between the liquid outlet 12 and the horizontal plane is 20-80°; preferably, the angle between the liquid outlet 12 and the horizontal plane is 45-60°, so as to form a complete water film on the inner wall of the main body 10 to prevent polishing contaminants from crystallizing on the inner wall of the main body 10.

[0074] As an embodiment of the present invention, the liquid outlet 12 can also be a long strip hole, which is arranged along the circumference of the main body 10. That is, the number of liquid outlets 12 is one, and the liquid in the accommodating cavity 11 slowly overflows through the liquid outlet 12 to form a complete water film on the inner wall of the main body 10, so as to achieve moisturizing of the inner wall of the main body 10 and avoid crystallization of polishing pollutants. That is, a long strip liquid outlet 12 is arranged on the inner upper edge of the main body 10, which can avoid the problem of adjacent liquid outlets 12 not being covered by liquid in the scheme of setting multiple liquid outlets 12, thereby improving the moisturizing effect of the protective device.

[0075] It can be understood that the number of liquid outlets 12 of the long hole can be multiple, such as 2, 3, etc., and the liquid outlets 12 are arranged at intervals, or the liquid outlets 12 are arranged at intervals in the height direction of the main body 10, and the liquid outlets 12 have a certain intersection along the circumferential direction of the main body 10, thereby ensuring that a complete water film is formed on the inner wall of the main body 10.

[0076] Figure 4 It is a longitudinal cross-sectional view of a protective device 100 provided in one embodiment of the present invention. In this embodiment, a liquid outlet 12 is arranged at the top of the main body 10, and the liquid in the accommodating chamber 11 flows out through the liquid outlet 12, thereby covering the splashing area of ​​the polishing waste liquid centrifugally thrown out by the polishing disk to prevent crystals from forming on the inner wall of the main body 10.

[0077] Figure 4 In the embodiment, the top surface of the main body 10 is tilted inwardly, so that the liquid overflowing from the liquid outlet 12 can flow along the tilted top surface to the inner wall of the main body 10, thereby preventing the liquid from accumulating on the top surface of the main body 10. If too much liquid accumulates on the top surface of the main body 10, it will quickly move toward the inner wall of the main body 10, which will destroy the water film formed on the inner wall, which is not conducive to achieving a good moisturizing effect.

[0078] In some embodiments, the inclination angle between the top surface of the main body 10 and the horizontal plane is 10-40°. Preferably, the inclination angle between the top surface of the main body 10 and the horizontal plane is 30°, so as to properly control the flow rate of the liquid on the top surface of the main body 10 so that a complete liquid film can be quickly formed on the inner wall of the main body 10.

[0079] In the present invention, the inner upper edge of the main body 10 is arc-shaped, such as Figure 4 As shown, the liquid flowing out of the liquid outlet 12 flows smoothly toward the inner wall of the main body 10 via the inner upper edge, so as to control the influence of the angular structure of the main body 10 on the movement of the fluid and avoid the damage of the liquid film formed on the inner wall of the main body 10 by the newly inflowing liquid.

[0080] Figure 5 It is a longitudinal cross-sectional view of a protective device 100 provided in another embodiment of the present invention. In this embodiment, the top surface of the main body 10 is provided with an annular opening 13 facing inward, and the liquid flowing out of the liquid outlet 12 flows toward the inner wall of the main body 10 through the annular opening 13.

[0081] The annular opening 13 is disposed on one side of the main body 10 close to the inner side wall, and is disposed circumferentially along the top surface of the main body 10 to provide a place for the liquid overflowing from the liquid outlet 12 to flow.

[0082] Furthermore, the depth of the annular opening 13 is 0.5-3 mm, and the depth of the annular opening 13 is the distance between the top surface of the main body 10 and the bottom surface of the annular opening 13 .

[0083] Figure 5 In the embodiment shown, the liquid outlet 12 is arranged vertically upward, and is located at the corner of the annular opening 13. In this arrangement, the liquid overflowing from the liquid outlet 12 can wash the side wall of the annular opening 13, thereby achieving moisture retention of the side wall of the annular opening 13 and preventing crystallization of the side wall of the annular opening 13.

[0084] As a variation of this embodiment, the bottom surface of the annular opening 13 may also be extended downward and inward. Figure 6 As shown, the overflowing liquid flows toward the inner wall of the main body 10.

[0085] In the present invention, the liquid outlet 12 disposed on the top of the main body 10 may also be disposed to be inclined upward and inward, such as Figure 7 As shown, the liquid in the accommodating cavity 11 can smoothly flow to the inner wall of the main body 10 through the inclined liquid outlet 12 .

[0086] exist Figure 4-Figure 7In the illustrated embodiment, the liquid outlet 12 is disposed at the top of the main body 10, and the liquid overflowing from the liquid outlet 12 flows from top to bottom along the inner wall of the main body 10 to form a liquid film. In order to facilitate the formation of the liquid film, the surface roughness Ra value of the inner wall of the main body 10 is ≥6.3 μm, so that the stability of the liquid spreading is enhanced, and the droplets on the inner wall surface show a certain hydrophilicity, thereby improving the wettability of the inner wall of the main body 10, so as to facilitate the formation of a complete liquid film.

[0087] It should be noted that the liquid outlet 12 of the main body 10 can be combined in a variety of ways, that is, the liquid outlet 12 is set at the top and / or the inner upper edge of the main body 10, so that the liquid flowing out of the liquid outlet 12 covers the splashing area of ​​the polishing waste liquid centrifugally thrown out by the polishing disk, thereby achieving moisturizing of the inner wall of the main body 10 and preventing polishing contaminants from crystallizing on the inner wall of the main body 10.

[0088] In the present invention, the main body 10 is made of homopolymer polypropylene (PPH). Polypropylene is a polymer compound, which is polymerized from propylene monomers and has excellent physical and chemical properties; PPH is a product of β-modified polypropylene, which has a uniform and delicate Beta crystal structure, and has better chemical corrosion resistance, wear resistance, high temperature resistance, corrosion resistance, aging resistance and insulation, so that the liquid overflowing from the liquid outlet 12 forms a liquid film on the inner wall of the main body 10, thereby achieving the moisturizing of the main body 10.

[0089] It is understandable that the main body 10 may also be made of polyphenylene sulfide or polyetheretherketone to facilitate moisture retention of the inner wall of the main body 10 .

[0090] Figure 8 1 is a schematic diagram of a protective device 100 provided by another embodiment of the present invention. In this embodiment, the liquid outlet 12 is arranged at the top of the main body 10, and the outer cover plate 20 is arranged at the outer peripheral side of the main body 10. At the same time, a shielding portion 22 is arranged on the upper part of the outer cover plate 20 to shield the top of the main body 10, so that the liquid overflowing through the liquid outlet 12 can flow in the space defined between the top of the main body 10 and the shielding portion 22, and then infiltrate the inner wall of the main body 10 under the action of gravity.

[0091] Specifically, the shielding portion 22 extends horizontally to the inner side of the main body 10 and then extends vertically downward to form an L-shaped structure. The shielding portion 22 can prevent the polishing waste liquid from falling on the top of the main body 10 and then flowing along the overflow of the accommodating cavity 11 to the inner side wall of the main body 10.

[0092] However, the shielding portion 22 also has a disadvantage: the polishing waste liquid may adhere to the upper surface of the shielding portion 22 and form crystals. To solve this problem, the upper surface of the shielding portion 22 is coated with a hydrophobic coating to inhibit the liquid from staying on the upper surface of the shielding portion 22. It is understood that the shielding portion 22 can be made of a material with good hydrophobicity as a whole.

[0093] At the same time, the present invention also provides a chemical mechanical polishing system 1000, the schematic diagram of which is as follows: Fig. 9 The chemical mechanical polishing system 1000 includes a polishing plate 200, a carrier head 300, a liquid supply device 400 and a trimming device 500, and further includes Figure 1 A protective device 100 is shown.

[0094] Specifically, the polishing pad is arranged on the upper surface of the polishing disk 200 and rotates along the axis together with the polishing disk 200; the horizontally movable carrying head 300 is arranged above the polishing pad, and the wafer to be polished is loaded on its lower surface; the dressing device 500 includes a dressing arm and a dressing head, which is arranged on one side of the polishing disk 200, and the dressing arm drives the rotating dressing head to swing to dress the surface of the polishing pad; the liquid supply device 400 is arranged on the upper side of the polishing pad to spread the polishing liquid on the surface of the polishing pad.

[0095] The protective device 100 is arranged on the outer peripheral side of the polishing disk 200. The main body 10 of the protective device 100 is internally provided with a accommodating cavity 11. The liquid in the accommodating cavity 11 can flow to the inner wall of the main body 10 through the liquid outlet 12, thereby moisturizing the inner wall of the main body 10 and preventing crystallization from forming on the inner wall of the main body 10.

[0096] In addition, the present invention also provides a polishing method, wherein Fig. 9 Polishing is performed in the chemical mechanical polishing system 1000 shown. During the chemical mechanical polishing process, the liquid in the accommodating cavity 11 of the main part 10 flows to the inner wall of the main part 10 through the liquid outlet 12 to achieve moisturizing of the inner wall of the main part 10, prevent polishing contaminants from crystallizing on the inner wall of the main part 10, and thereby avoid wafer scratch defects.

[0097] Those of ordinary skill in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present application.

[0098] The above implementation methods are only used to illustrate the embodiments of the present application, and are not limitations on the embodiments of the present application. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present application. The scope of patent protection of the embodiments of the present application should be limited by the claims.

Claims

1. A protective device for protecting a polishing disc in a chemical mechanical polishing system, characterized in that: The main body comprises an annular main body and is located on the outer peripheral side of the polishing disc; the main body comprises: The accommodating cavity is arranged inside the main body and is used for caching liquid; A liquid outlet, which is arranged on the inner side of the main body and communicates with the accommodating cavity; The liquid in the accommodating cavity flows to the inner side wall of the main body through the liquid outlet to achieve moisturizing of the inner side wall of the main body.

2. The protective device according to claim 1, characterized in that: The liquid outlet is arranged at the top and / or the inner upper edge of the main body, so that the liquid flowing out of the liquid outlet covers the splashing area of ​​the polishing waste liquid centrifugally thrown out by the polishing disk.

3. The protective device according to claim 1, characterized in that: There are multiple liquid outlets, which are arranged at intervals along the circumference of the main body.

4. The protection device according to claim 2, characterized in that: The top surface of the main body is inclined toward the inside.

5. The protection device according to claim 2, characterized in that: The inner upper edge of the main body is in arc transition, so that the liquid flowing out of the liquid outlet flows smoothly toward the inner wall of the main body via the inner upper edge.

6. The protection device according to claim 2, characterized in that: The top surface of the main body is provided with an annular opening facing inward, and the liquid flowing out of the liquid outlet flows toward the inner wall of the main body through the annular opening.

7. The protection device according to claim 2, characterized in that: The liquid outlet located at the top of the main body is arranged to be inclined upward and inward.

8. The protection device according to claim 6, characterized in that: The liquid outlet located at the top of the main body is arranged vertically upward, and the liquid outlet is located at the corner of the annular opening.

9. The protection device according to claim 2, characterized in that: The liquid outlet located at the inner upper edge of the main body is arranged to be inclined upward and inward.

10. The protection device according to claim 1, characterized in that: It also includes an outer cover plate, which is matched with the main body to form the accommodating cavity; the outer cover plate is configured with a liquid inlet, which is connected to an external liquid source to transport the liquid to the accommodating cavity.

11. The protection device according to claim 10, characterized in that: The main body is provided with an annular groove, and the outer cover is arranged on the outer side of the annular groove to form the accommodating cavity.

12. The protection device according to claim 10, characterized in that: The setting height of the liquid inlet is less than or equal to the height of the liquid outlet.

13. The protection device according to claim 1, characterized in that: The main body is made of homopolymer polypropylene, polyphenylene sulfide or polyetheretherketone.

14. The protection device according to claim 1, characterized in that: The liquid outlet is arranged at the top of the main body, and the surface roughness Ra value of the inner wall of the main body is ≥6.3 μm.

15. A chemical mechanical polishing system, characterized in that: It includes a polishing disk, a carrying head, a liquid supply device and a trimming device, wherein the carrying head presses the wafer to be polished against the polishing pad above the polishing disk, the liquid supply device supplies polishing liquid between the polishing pad and the wafer, and the trimming device is used to trim the surface of the polishing pad; it also includes the protective device according to any one of claims 1 to 14, so as to achieve moisturizing of the inner side wall of the main body and prevent crystallization from forming on the inner side wall of the main body.

16. A polishing method, wherein polishing is performed in the chemical mechanical polishing system of claim 15, wherein during the chemical mechanical polishing process, the liquid in the receiving cavity of the main body flows to the inner wall of the main body through the liquid outlet to achieve moisturizing of the inner wall of the main body.

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