Liquid drainage device for chemical mechanical polishing equipment and chemical mechanical polishing equipment

Abstract

The utility model provides a liquid discharging device for chemical mechanical polishing equipment and the chemical mechanical polishing equipment. The liquid discharging device comprises a main liquid discharging pipe, a backflow monitoring device, an auxiliary liquid discharging pipe and an emergency liquid discharging pipe. The main liquid discharge pipe is communicated with the grinding cavity, and the auxiliary liquid discharge pipe and the emergency liquid discharge pipe are respectively connected with the main liquid discharge pipe and are used for discharging grinding waste liquid in the grinding cavity; the backflow monitoring device is arranged on the upstream of the auxiliary liquid discharge pipe and the emergency liquid discharge pipe; and a valve is arranged at the joint of the emergency liquid discharge pipe and the main liquid discharge pipe. According to the scheme, the backflow monitoring device is used for monitoring the liquid discharging condition, the blockage problem of the liquid discharging pipeline can be found in time, liquid discharging can be conducted for continuous production under the non-stop condition through the arranged emergency liquid discharging pipe, the liquid discharging device does not need to be independently maintained, and the maintenance pressure is greatly reduced.

Description

Technical Field

[0001] This application relates to the field of semiconductor equipment, and in particular to a draining device for a chemical mechanical polishing (CMP) device and a CMP device. Background Technology

[0002] Chemical mechanical polishing (CMP) is the most common global planarization technique in semiconductor manufacturing. The principle of CMP is a processing technique that combines chemical action and mechanical removal. During the process, a continuous supply of polishing slurry is required, while the resulting waste slurry is discharged through the equipment's drain pipes.

[0003] Grinding waste liquid has a complex composition, including grinding fluid and various grinding byproducts, and easily forms viscous crystals. Therefore, during the drainage process, the crystals in the waste liquid continuously accumulate on the side walls and bends of the drainage pipe, eventually causing blockage and hindering drainage. This, in turn, leads to liquid accumulation or even leakage within the grinding chamber.

[0004] To reduce the risk of liquid accumulation and leakage, existing technologies propose installing a leakage detection device in the drainage pipe. When the detection device alarm is triggered, the supply of grinding fluid is cut off and the machine is shut down for unblocking. However, while this setup can reduce the risk of leakage, it requires manual shutdown for maintenance each time, increasing maintenance costs.

[0005] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Utility Model Content

[0006] To address all or part of the problems in the prior art, this invention provides a drainage device for chemical mechanical polishing (CMP) equipment and the CMP equipment itself, thereby reducing the risk of liquid accumulation and leakage in CMP equipment and the maintenance pressure caused by maintaining the drainage device separately.

[0007] To achieve the above objectives, in a first aspect, this utility model provides a drainage device for chemical mechanical polishing equipment, including a main drainage pipe, a reflux monitoring device, a secondary drainage pipe, and an emergency drainage pipe;

[0008] The main drain pipe is connected to the grinding chamber, and the auxiliary drain pipe and the emergency drain pipe are respectively connected to the main drain pipe to discharge the grinding waste liquid in the grinding chamber;

[0009] The backflow monitoring device is located upstream of the auxiliary drain pipe and the emergency drain pipe;

[0010] A valve is installed at the connection between the emergency drain pipe and the main drain pipe.

[0011] This solution monitors the drainage status through a reflux monitoring device, which can promptly detect blockages in the drainage pipe. Furthermore, the emergency drainage pipe allows production to continue without shutting down the machine, eliminating the need for separate maintenance of the drainage device and significantly reducing maintenance burden.

[0012] In some embodiments, the main drain pipe and the emergency drain pipe are connected via a drain adapter, with the angle θ between the drain adapter and the main drain pipe between 90° and 180°. This design reduces the possibility of liquid backflow into the emergency drain pipe during normal drainage and allows liquid to flow back into the main drain pipe when drainage is finished, reducing liquid residue on the drain adapter.

[0013] In some embodiments, the valve is located at the connection between the drain adapter and the emergency drain pipe. This reduces contact between the grinding waste liquid and the valve, thus extending its service life.

[0014] In some embodiments, the connection point between the emergency drain pipe and the main drain pipe is located upstream of the auxiliary drain pipe. Positioning the emergency drain pipe upstream of a clog-prone area ensures effective discharge of grinding waste liquid when the emergency drain pipe is opened.

[0015] In some embodiments, the backflow monitoring device includes a backflow pipe and a liquid monitor; the backflow pipe is located upstream of the auxiliary drain pipe and the emergency drain pipe, the inlet of the backflow pipe is located inside the main drain pipe, and the outlet of the backflow pipe is connected to the liquid monitor. The backflow pipe can effectively prevent liquid in the main drain pipe from flowing into the liquid monitor during normal drainage, reducing the possibility of false triggering.

[0016] In some embodiments, the inlet direction of the return pipe is opposite to the flow direction of the grinding waste liquid in the main drain pipe. This further prevents liquid in the main drain pipe from flowing into the liquid monitor during normal drainage, reducing the possibility of false triggering.

[0017] In some embodiments, a controller is also included, connected to the liquid monitor, which controls the opening and closing of the valve based on signals from the liquid monitor. This allows for automatic switching of the drainage line in case of blockage, reducing the risk of liquid accumulation and leakage caused by delays in manual operation.

[0018] In some embodiments, the valve is a pneumatic valve or an electric valve. This facilitates automatic control and reduces human error.

[0019] In some embodiments, an alarm is also included, which is connected to the liquid monitor. Triggering the alarm provides timely alerts, facilitating appropriate action and situation confirmation by the operator.

[0020] Secondly, this application also provides a chemical mechanical polishing apparatus, including the draining device described in any of the first aspects.

[0021] Compared with the prior art, the main beneficial effects of this utility model are: This solution monitors the drainage situation through a backflow monitoring device, which can detect blockage problems in the drainage pipe in a timely manner. Furthermore, through the emergency drainage pipe, production can continue without stopping the machine, without the need for separate maintenance of the drainage device, which greatly reduces the maintenance pressure. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the specific embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of an existing drainage device.

[0024] Figure 2 This is a schematic diagram of a drainage device provided in Embodiment 1. Detailed Implementation

[0025] The foregoing and other technical contents, features, and effects of this utility model will be clearly presented in the following detailed description of the preferred embodiments with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are only for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the scope of this utility model.

[0026] Chemical mechanical polishing (CMP) is the most common global planarization technique in semiconductor manufacturing. In CMP equipment, the polishing waste solution inside the polishing chamber is discharged through a drainage pipe. However, due to the characteristics of the polishing waste solution itself, it is very prone to crystal formation, which can then clog the drainage pipe.

[0027] like Figure 1As shown, the existing CMP equipment's drainage device includes a drainage pipe 2 connecting the grinding chamber 1. Grinding waste liquid 3 to be drained is present in the grinding chamber 1 and the drainage pipe 2. It is understood that crystals 4 are easily generated in the grinding waste liquid 3. The crystals 4 are usually viscous substances with poor fluidity. They often accumulate in narrow parts, bends, or connections of the pipe, causing blockage of the drainage pipe. Consequently, the liquid in the grinding chamber 1 cannot be drained in time, resulting in liquid accumulation, leakage, and other situations.

[0028] Example 1:

[0029] Figure 2 This is a schematic diagram of the drainage device in Example 1.

[0030] In this embodiment, a drainage device for a chemical mechanical polishing (CMP) apparatus is provided, comprising a drainage pipe 2 connected to the grinding chamber 1 for discharging grinding waste liquid 3; the drainage pipe 2 includes a main drainage pipe 20, a secondary drainage pipe 21 connected to the main drainage pipe 20, and an emergency drainage pipe 22 connected to the main drainage pipe 20; the emergency drainage pipe 22 is located upstream of the secondary drainage pipe 21 (in this application, the direction in front of the normal flow of grinding waste liquid 3 in the drainage pipe during drainage is considered upstream, and the corresponding direction behind is considered downstream), and a valve 6 is provided at the connection between the emergency drainage pipe 22 and the main drainage pipe; a backflow monitoring device 5 is also provided in the drainage device, and the backflow monitoring device 5 is located upstream of the secondary drainage pipe 21 and the emergency drainage pipe 22. When the drainage device of the CMP equipment is operating normally, valve 6 of the emergency drainage pipe 22 is closed, and the grinding waste liquid 3 is discharged through the main drainage pipe 20 and the auxiliary drainage pipe 21. Commonly blocked locations (i.e., narrow sections, bends, or connections in the pipes) are usually located at the auxiliary drainage pipe 21. Therefore, when the auxiliary drainage pipe 21 is blocked, the grinding waste liquid 3 cannot be discharged in time, triggering the backflow monitoring device 5. This allows the valve 6 to be opened, enabling the grinding waste liquid 3 to be discharged promptly through the main drainage pipe 20 and the emergency drainage pipe 22, preventing liquid accumulation and leakage. This device can promptly monitor whether the drainage device is blocked and allows production to continue without stopping the machine for maintenance. All pipes of the drainage device are cleaned and maintained during the PM cycle, greatly reducing maintenance costs.

[0031] In this embodiment, to reduce the contact between valve 6 and liquid during normal operation, a drain adapter 23 is provided. The drain adapter 23 connects the emergency drain pipe 22 and the main drain pipe 20, and valve 6 is located at the connection between the drain adapter 23 and the emergency drain pipe 22. (Reference) Figure 2As shown, it can be understood that the main drain pipe 20, which is directly connected to the grinding chamber 1 in the CMP equipment, is usually perpendicular to the ground. The normal flow direction of the grinding waste liquid 3 in the main drain pipe 20 is from top to bottom. However, in this embodiment, an upward angle is set between the drain adapter 23 and the drain pipe 20. This angle θ is between 90° and 180° (that is, in this application, the angle θ is: 90° < θ < 180°). This can reduce the possibility of the grinding waste liquid 3 flowing back to the emergency drain pipe 22 during normal drainage. It can also make the liquid flow back to the main drain pipe 20 when the drainage ends, reduce the liquid residue on the drain adapter 23, and avoid contact with the valve 6.

[0032] refer to Figure 2 As shown, in this embodiment, the backflow monitoring device 5 includes a backflow pipe 50 and a liquid monitor 51. The backflow pipe 50 is located upstream of the auxiliary drain pipe 21 and the emergency drain pipe 22. The inlet of the backflow pipe 50 is located inside the main drain pipe 20, and the outlet of the backflow pipe 50 is connected to the liquid monitor 51. The liquid monitor 51 is a contact sensor that generates a corresponding signal when it comes into contact with liquid. The backflow pipe 50 has a two-section structure, one section of which extends into the interior of the main drain pipe 20, i.e., the inlet of the backflow pipe 50 is located inside the main drain pipe 20, and the inflow direction of the backflow pipe 50 is opposite to the flow direction of the grinding waste liquid 3 in the main drain pipe 20. Through this backflow monitoring device 5, during normal drainage, the grinding waste liquid 3 will not enter from the backflow pipe 50 and will not trigger the liquid monitor 51. When the drain pipe is blocked, the grinding waste liquid 3 will be introduced into the liquid monitor 51 through the backflow pipe 50 and trigger it.

[0033] In this embodiment, a controller (not shown in the figure) and an alarm (not shown in the figure) are also provided. In other embodiments, the controller and alarm may or may not be provided. In this embodiment, the controller is connected to the liquid monitor 51 and controls the opening and closing of the valve 6 according to the signal from the liquid monitor 51. The valve 6 can be a pneumatic valve or an electric valve. It is understood that the connection between the controller and the liquid monitor 51 is not limited to a physical connection (e.g., a connection via a wire), but can also be a signal connection. Its main purpose is to transmit the signal from the liquid monitor 51 to the controller, so that the controller controls the opening and closing of the valve 6 according to the signal, thereby realizing the automatic switching of the drainage pipeline. Similarly, the alarm is also connected to the liquid monitor 51 and issues an alarm according to the signal from the liquid monitor 51.

[0034] This application also provides a chemical mechanical polishing apparatus, which includes the drainage device described above.

[0035] The common English terms or letters used in this invention for the purpose of clarity are for illustrative purposes only and are not intended to be limiting or specific. They should not be used to limit the scope of protection of this invention based on their possible Chinese translations or specific letters.

[0036] It should also be noted that in this article, relational terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A draining device for a chemical mechanical polishing (CMP) machine, characterized in that, Includes main drain pipe, reflux monitoring device, auxiliary drain pipe and emergency drain pipe; The main drain pipe is connected to the grinding chamber, and the auxiliary drain pipe and the emergency drain pipe are respectively connected to the main drain pipe to discharge the grinding waste liquid in the grinding chamber; The backflow monitoring device is located upstream of the auxiliary drain pipe and the emergency drain pipe; A valve is installed at the connection between the emergency drain pipe and the main drain pipe.

2. The draining device for a chemical mechanical polishing apparatus according to claim 1, characterized in that, The main drain pipe and the emergency drain pipe are connected by a drain adapter, and the angle θ between the drain adapter and the main drain pipe is between 90° and 180°.

3. The draining device for a chemical mechanical polishing apparatus according to claim 2, characterized in that, The valve is located at the connection between the drain transfer pipe and the emergency drain pipe.

4. The draining device for a chemical mechanical polishing apparatus according to claim 1, characterized in that, The connection point between the emergency drain pipe and the main drain pipe is located upstream of the auxiliary drain pipe.

5. The draining device for a chemical mechanical polishing apparatus according to claim 1, characterized in that, The reflux monitoring device includes a reflux pipe and a liquid monitor; The return pipe is located upstream of the auxiliary drain pipe and the emergency drain pipe. The inlet of the return pipe is located inside the main drain pipe, and the outlet of the return pipe is connected to the liquid monitor.

6. The draining device for a chemical mechanical polishing apparatus according to claim 5, characterized in that, The inlet direction of the return pipe is opposite to the flow direction of the grinding waste liquid in the main drain pipe.

7. The draining device for a chemical mechanical polishing apparatus according to claim 5, characterized in that, It also includes a controller connected to the liquid monitor, which controls the opening and closing of the valve based on the signal from the liquid monitor.

8. The draining device for a chemical mechanical polishing apparatus according to claim 7, characterized in that, The valve is either a pneumatic valve or an electric valve.

9. A draining device for a chemical mechanical polishing apparatus according to claim 5, characterized in that, It also includes an alarm that is connected to the liquid monitor.

10. A chemical mechanical polishing apparatus, characterized in that, Includes the draining device as described in any one of claims 1-9.

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