Wafer polishing system

Abstract

The utility model discloses a wafer polishing system which at least comprises a polishing table with a polishing pad, a polishing head used for driving a wafer to move relative to the polishing table, and a polishing liquid arm used for conveying polishing liquid to the polishing table, an atomizing spray head is arranged in the space where the polishing table is located, and the atomizing spray head sprays liquid to the area where the polishing pad is located. To form a wetted region on the polishing pad. Atomization wetting of the polishing pad is achieved through the atomization nozzle, the spraying coverage range of the atomization nozzle is large, meanwhile, water consumption is small, and the atomization function can be achieved with the minimum cost; the atomization is realized on the premise of not adding a new water source and a new control structure, and the influence on the work of the wafer polishing system is avoided; and the atomizing nozzle can be flexibly switched between a working state and a closed state, can also be disassembled and assembled at any time, can be flexibly applied to different polishing processes, and is high in use flexibility.

Description

Technical Field

[0001] The utility model belongs to the technical field of semiconductor integrated circuit chip manufacturing, in particular to a wafer polishing system. Background Art

[0002] With the continuous advancement of semiconductor production and processing technology, the CMP grinding process has been continuously iterated and updated, and the types of grinding and polishing pads have continued to increase. Due to the material characteristics of some newly emerging types of polishing pads, they need to be kept wet at all times to maintain their physical properties and ensure the grinding effect.

[0003] At present, one or more water pipes are mainly used to continuously supply water to the polishing pad to ensure that the polishing pad is always in a wet state. In this implementation method, when the water flow rate of the water pipe is set to a small amount, the water may not be able to completely cover the entire polishing pad, and the characteristics of the polishing pad will change, and there is a possibility of failure. When the water flow rate of the water pipe is set to a large amount, although the water can completely cover the entire polishing pad after a period of time, the water consumption is large and the wetting cost is too high. Therefore, it is very necessary to know how to evenly wet the polishing pad. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art, the utility model provides a wafer polishing system, which utilizes an atomizing nozzle to spray liquid onto a polishing pad, so that the polishing pad is kept in a wet state, and has low water consumption and reduced wetting costs.

[0005] The technical solution adopted by the utility model to solve its technical problems is: a wafer polishing system, which at least includes a polishing table with a polishing pad, a polishing head used to drive the wafer to move relative to the polishing table, and a polishing liquid arm used to transport polishing liquid to the polishing table. An atomizing nozzle is provided in the space where the polishing table is located, and the atomizing nozzle sprays liquid to the area where the polishing pad is located to form a wetting area on the polishing pad.

[0006] Furthermore, the atomizing nozzle is located above the polishing table, including the atomizing nozzle being located directly above the polishing table, and the atomizing nozzle being located obliquely above the polishing table; the number of the atomizing nozzles is one or two or more.

[0007] Furthermore, the wetted area extends over the entire polishing pad.

[0008] Furthermore, the wetted area also includes an area near the polishing pad.

[0009] Furthermore, the polishing table and / or the atomizing nozzle rotates, and the coverage width of the liquid sprayed by a single atomizing nozzle on the polishing pad is greater than or equal to the radius of the polishing pad.

[0010] Furthermore, the atomizing nozzle is connected to the polishing liquid arm, and / or, the atomizing nozzle is connected to the dressing arm, and / or, the atomizing nozzle is connected to the polishing head.

[0011] Furthermore, the atomizing nozzle is connected to a liquid circulation channel, and the liquid circulation channel has a water inlet joint, and the water inlet joint is connected to the polishing liquid arm.

[0012] Further, the atomizing nozzle is connected to the first cleaning unit of the polishing liquid arm; or, the atomizing nozzle is connected to the second cleaning unit of the dressing arm.

[0013] Furthermore, the wafer polishing system has a process state and a non-process state, and the atomizing nozzle has a working state and a closed state. When the wafer polishing system is in the non-process state, the atomizing nozzle enters the working state.

[0014] Further, the process state is a polishing process, or the process state is a polishing pad cleaning process.

[0015] Furthermore, the flow rate of the liquid sprayed by the atomizing nozzle is greater than or equal to 0.01 L / min; the liquid is ultrapure water, or a chemical liquid, and the chemical liquid is a polishing liquid, an electrolyte, or an organic solution.

[0016] Furthermore, it also includes a liquid infusion tube, which delivers the wetting fluid to the polishing pad.

[0017] Furthermore, the vertical height difference between the atomizing nozzle and the polishing table is 50-200 mm.

[0018] The beneficial effects of the utility model are: 1) atomization wetting of the polishing pad is achieved by means of an atomizing nozzle, the spray coverage of the atomizing nozzle is large, and the water consumption is small, and the atomization function can be achieved at the lowest cost; 2) atomization is achieved without adding a new water source and a new control structure, and the operation of the wafer polishing system itself will not be affected; 3) the atomizing nozzle can be flexibly switched between the working state and the closed state, and can also be disassembled and assembled at any time, and can be flexibly applied to different polishing processes, with high flexibility of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The three-dimensional structure of the utility model is shown in FIG. Figure 1 .

[0020] Figure 2 It is a top view of the utility model.

[0021] Figure 3 The three-dimensional structure of the utility model is shown in FIG. Figure 2 .

[0022] Figure 4 The three-dimensional structure of the utility model is shown in FIG. Figure 3 At this time, the polishing liquid arm is provided with an atomizing nozzle.

[0023] Figure 5 The three-dimensional structure of the utility model is shown in FIG. Figure 4 At this time, the trimming arm is provided with an atomizing nozzle.

[0024] Figure 6 It is a three-dimensional structural schematic diagram of the polishing table and multiple atomizing nozzles in the utility model.

[0025] Figure 7 It is a three-dimensional structural schematic diagram of the polishing table and a single atomizing nozzle in the utility model.

[0026] Figure 8 It is a front view of the polishing table and a single atomizing nozzle in the utility model.

[0027] Among them, 1-polishing table, 11-polishing pad, 111-wetting area, 2-polishing head, 3-polishing liquid arm, 4-atomizing nozzle, 5-liquid flow channel, 6-water inlet joint, 7-dressing arm. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solution of the utility model, the following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0029] like Figure 1 As shown, a wafer polishing system at least includes a polishing table 1 with a polishing pad 11 , a polishing head 2 for driving the wafer to move relative to the polishing table 1 , and a polishing liquid arm 3 for conveying polishing liquid to the polishing table 1 .

[0030] An atomizing nozzle 4 is provided in the space where the polishing table 1 is located. The atomizing nozzle 4 sprays liquid to the area where the polishing pad 11 is located, thereby forming a wetted area 111 on the polishing pad 11 .

[0031] In particular, the wafer polishing system has a process state and a non-process state, and the atomizing nozzle 4 has a working state and a closed state. When the wafer polishing system is in a non-process state, specifically, the process state is a polishing process, or the process state is a polishing pad cleaning process, at which time the atomizing nozzle 4 enters a working state. In other words, when the wafer polishing system is in a process state, due to the effect of chemical liquids such as polishing liquid and cleaning liquid, the polishing pad 11 can be in a wet state, and at this time, the atomizing nozzle 4 does not need to spray liquid on the polishing pad 11. Once the wafer polishing system is in a non-process state, the polishing liquid or cleaning liquid will not be delivered to the polishing pad 1, and the atomizing nozzle 4 needs to spray liquid on the polishing pad 1 to keep it in a wet state, and the amount of liquid sprayed by the atomizing nozzle 4 will not be too large. Specifically, the flow rate of the liquid sprayed by the atomizing nozzle 4 is greater than or equal to 0.01L / min, so the water consumption is reduced, the wetting cost is reduced, and the atomizing nozzle 4 sprays liquid in a wide range, a large wetting area, high wetting efficiency, and good wetting effect. Of course, in addition to ultrapure water, the liquid sprayed by the atomizing nozzle 4 can also be a chemical liquid, which can specifically be a polishing liquid, an electrolyte, or an organic solution.

[0032] The above structure does not limit the position of the atomizing nozzle 4 , which may be located above the polishing table 1 , at the side of the polishing table 1 , or below the polishing table 1 .

[0033] In this embodiment, the atomizing nozzle 4 is located above the polishing table 1, which includes the atomizing nozzle 4 being located directly above the polishing table 1 and the atomizing nozzle 4 being located obliquely above the polishing table 1. The vertical height difference between the atomizing nozzle 4 and the polishing table 1 is 50-200 mm, that is, Figure 8 Medium H = 50-200mm.

[0034] There is no specific limitation on the number of the atomizing nozzles 4, which can be one, two, or more than two. Figure 6 , Figure 7 In this embodiment, the atomizing nozzle 4 can be a common nozzle with a large liquid spraying angle, or a fan-shaped nozzle, or a cone-shaped nozzle, or a multi-fluid nozzle, which are all existing products, and the specific structure will not be repeated.

[0035] The wet area 111 formed on the polishing pad 11 means that the polishing pad 11 receives the liquid sprayed by the atomizing nozzle 4, so that the part of the polishing pad 11 is wetted. The wet area 111 can extend the entire polishing pad 11 or a part of the polishing pad 11, and there is no specific limitation.

[0036] The atomizing nozzle 4 can be fixed or rotatable. The polishing table 1 rotates with the polishing pad 11, and at this time, it can cooperate with the fixed atomizing nozzle 4 to wet the entire polishing pad 11. At this time, the coverage width of the liquid sprayed by a single atomizing nozzle 4 on the polishing pad 11 is greater than or equal to the radius of the polishing pad 11. Figure 7 It can also cooperate with the rotating atomizing nozzle 4 to achieve the wetting of the entire polishing pad 11.

[0037] The source of the liquid sprayed by the atomizing nozzle 4 can be divided into multiple situations according to the structure of the wafer polishing system itself. For example, the atomizing nozzle 4 is connected to the polishing liquid arm 3. Figure 4 As shown, when the polishing liquid arm 3 is in a non-working state, the atomizing nozzle 4 can enter a working state; or, the atomizing nozzle 4 is connected to the dressing arm 7, as shown in FIG. Figure 5 As shown, when the dressing arm 7 is in a non-working state, the atomizing nozzle 4 can enter a working state; alternatively, the atomizing nozzle 4 is connected to the polishing head, or alternatively, the atomizing nozzle 4 is simultaneously connected to two or three of the polishing liquid arm 3, the dressing arm 7, and the polishing head, without specific limitation.

[0038] Specifically, the internal structure of the polishing liquid arm 3 itself has a first cleaning unit, and when the atomizing nozzle 4 is connected to the polishing liquid arm 3, the atomizing nozzle 4 is connected to the first cleaning unit. The internal structure of the dressing arm 7 itself has a second cleaning unit, and when the atomizing nozzle 4 is connected to the dressing arm 7, the atomizing nozzle 4 is connected to the second cleaning unit.

[0039] The atomizing nozzle 4 is connected to the liquid circulation channel 5, and the liquid circulation channel 5 has a water inlet joint 6, and the water inlet joint 6 is connected to the polishing liquid arm 3. In this embodiment, the liquid circulation channel 5 is a pipeline connected to the polishing liquid arm 3, more specifically, the liquid circulation channel 5 is a pipeline connected to the polishing liquid arm 3 and the trimming arm 7, as shown in FIG. Figure 2 As shown, there are three atomizing nozzles 4, which are respectively arranged corresponding to the polishing liquid arm 3 and the trimming arm 7. Specifically, they are evenly spaced from the polishing head 2 support arm and arranged around the polishing table 1. The atomizing nozzle 4 can be independently and detachably connected to the liquid flow channel 5 by snap-fitting, screw connection, etc.

[0040] Of course, when the atomizing nozzle 4 is provided, a liquid infusion tube can also be provided, which can deliver flowing wetting fluid to the polishing pad 11, and its liquid delivery volume is relatively large. The atomizing nozzle 4 and the liquid infusion tube can be used at the same time, or the atomizing nozzle 4 can be used alone.

[0041] The above specific implementation modes are used to explain the present invention rather than to limit the present invention. Any modification and change made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A wafer polishing system, comprising at least a polishing table with a polishing pad, a polishing head for driving the wafer to move relative to the polishing table, and a polishing liquid arm for delivering polishing liquid to the polishing table, characterized in that: An atomizing nozzle is arranged in the space where the polishing table is located, and the atomizing nozzle sprays liquid to the area where the polishing pad is located to form a wetting area on the polishing pad.

2. The wafer polishing system according to claim 1, characterized in that: The atomizing nozzle is located above the polishing table, including the atomizing nozzle being located directly above the polishing table and the atomizing nozzle being located obliquely above the polishing table; the number of the atomizing nozzles is one, two, or more than three.

3. The wafer polishing system according to claim 1 or 2, characterized in that: The wetted area extends across the polishing pad.

4. The wafer polishing system according to claim 3, characterized in that: The wetted area also includes an area near the polishing pad.

5. The wafer polishing system according to claim 1, characterized in that: The polishing table and / or the atomizing nozzle rotates, and the coverage width of the liquid sprayed by a single atomizing nozzle on the polishing pad is greater than or equal to the radius of the polishing pad.

6. The wafer polishing system according to claim 1, characterized in that: The atomizing nozzle is connected to the polishing liquid arm, and / or, the atomizing nozzle is connected to the dressing arm, and / or, the atomizing nozzle is connected to the polishing head.

7. The wafer polishing system according to claim 1 or 2, characterized in that: The atomizing nozzle is connected to a liquid circulation channel, and the liquid circulation channel is provided with a water inlet joint, and the water inlet joint is connected to a polishing liquid arm.

8. The wafer polishing system according to claim 1 or 2, characterized in that: The atomizing nozzle is connected to the first cleaning unit of the polishing liquid arm; or, the atomizing nozzle is connected to the second cleaning unit of the dressing arm.

9. The wafer polishing system according to claim 1, characterized in that: The wafer polishing system has a process state and a non-process state, and the atomizing nozzle has a working state and a closed state. When the wafer polishing system is in the non-process state, the atomizing nozzle enters the working state.

10. The wafer polishing system according to claim 9, characterized in that: The process state is a polishing process, or the process state is a polishing pad cleaning process.

11. The wafer polishing system according to claim 1 or 2, characterized in that: The flow rate of the liquid sprayed by the atomizing nozzle is greater than or equal to 0.01 L / min; the liquid is ultrapure water, or a chemical liquid, and the chemical liquid is a polishing liquid, an electrolyte, or an organic solution.

12. The wafer polishing system according to claim 1, characterized in that: Also included is a fluid delivery tube that delivers a dampening fluid to the polishing pad.

13. The wafer polishing system according to claim 1, characterized in that: The vertical height difference between the atomizing nozzle and the polishing table is 50-200 mm.

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