TWI808446B - Wafer cleaning system and wafer cleaning method - Google Patents

Abstract

A wafer cleaning system used for cleaning a wafer and including a wafer cleaning brush, a cleaning solution, and a negative voltage generator is provided. In the working state, the wafer cleaning brush contacts the surface of the wafer. The cleaning solution is provided to the surface of the wafer. The cleaning solution is conductive. The negative voltage generator provides a negative voltage to the cleaning solution.

Description

Wafer cleaning system and wafer cleaning method

The embodiments of the present invention relate to a cleaning system and a cleaning method, and in particular to a wafer cleaning system and a wafer cleaning method.

After the semiconductor manufacturing process is completed, the wafer is often cleaned to maintain the cleanliness of the wafer. For example, after a chemical mechanical polishing (CMP) process is performed on the wafer, a cleaning process is performed on the wafer using a wafer cleaning brush and a cleaning solution. However, when an alkaline cleaning solution is used for post-CMP cleaning, the metal (eg, tungsten contact) on the wafer is easily dissociated, and depressions are formed on the metal (eg, tungsten contact), which is prone to open circuit problems and lower yields. In addition, the above-mentioned problems are more likely to occur on metals (eg, tungsten contacts) electrically connected to PMOS transistors.

The invention provides a wafer cleaning system and a wafer cleaning method, which can have Effectively prevent the metal on the wafer from being dissociated during the cleaning process.

The present invention provides a wafer cleaning system for cleaning wafers, and includes a wafer cleaning brush, a cleaning solution and a negative voltage generator. In the working state, the wafer cleaning brush contacts the surface of the wafer. A cleaning solution is provided to the surface of the wafer. Cleaning solutions are conductive. The negative voltage generator provides negative voltage to the cleaning solution.

According to an embodiment of the present invention, in the above-mentioned wafer cleaning system, there may be two wafer cleaning brushes, and the two wafer cleaning brushes are arranged on opposite sides of the wafer.

According to an embodiment of the present invention, the above wafer cleaning system may further include a core body. The wafer cleaning brush is sheathed on the core body. The core can be hollow and can have a plurality of holes. Electrodes of the negative voltage generator may be provided inside the core.

According to an embodiment of the present invention, the above wafer cleaning system may further include a cleaning solution supply device. The cleaning solution supply device is arranged outside the core body and communicated with the core body to inject the cleaning solution into the core body.

According to an embodiment of the present invention, the above wafer cleaning system may further include a cleaning solution supply device. The cleaning solution supply device is arranged above the wafer cleaning brush. The cleaning solution supply device sprays the cleaning solution onto the surface of the wafer. Electrodes of the negative voltage generator may be provided inside the cleaning solution supply device.

According to an embodiment of the present invention, the above wafer cleaning system may further include a roller. In working condition, the roller touches the edge of the wafer.

The present invention proposes a wafer cleaning method, which includes the following steps. A cleaning solution is provided to the surface of the wafer, wherein the cleaning solution is conductive. Use wafer cleaning The brush and the cleaning solution perform a cleaning process on the surface of the wafer, wherein in the cleaning process, a negative voltage generator is used to provide a negative voltage to the cleaning solution.

According to an embodiment of the present invention, in the above wafer cleaning method, the wafer cleaning brush is sheathed on the core body. The core can be hollow and can have a plurality of holes. Electrodes of the negative voltage generator may be provided inside the core.

According to an embodiment of the present invention, in the above wafer cleaning method, the method for providing the cleaning solution to the surface of the wafer may include the following steps. The cleaning solution is injected into the core body through the cleaning solution supply device, and the cleaning solution passes through the holes of the core body and the wafer cleaning brush to reach the surface of the wafer.

According to an embodiment of the present invention, in the above wafer cleaning method, the method for providing the cleaning solution to the surface of the wafer may include the following steps. The cleaning solution is sprayed onto the surface of the wafer by the cleaning solution supply device. Electrodes of the negative voltage generator may be provided inside the cleaning solution supply device.

Based on the above, in the wafer cleaning system and wafer cleaning method proposed by the present invention, since a negative voltage generator can be used to provide a negative voltage to the cleaning solution during the cleaning process, the metal on the wafer can be effectively prevented from being dissociated during the cleaning process. In this way, the problem of open circuit can be effectively prevented, thereby improving the yield rate.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

100: Wafer cleaning system

102: Wafer cleaning brush

102a: Protrusion

104: cleaning solution

106: Negative voltage generator

106a: electrode

106b: wire

108: Core

108a: hole

110, 112: cleaning solution supply device

110a: pipeline

112a: Nozzle

114:Roller

S100, S102: steps

W: Wafer

FIG. 1 is a schematic diagram of a wafer cleaning system according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view along the line I-I' in Fig. 1 .

FIG. 3 is a flowchart of a wafer cleaning method according to an embodiment of the present invention.

FIG. 1 is a schematic diagram of a wafer cleaning system according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view along the line I-I' in Fig. 1 .

Referring to FIG. 1 and FIG. 2 , the wafer cleaning system 100 is used for cleaning the wafer W, and includes a wafer cleaning brush 102 , a cleaning solution 104 and a negative voltage generator 106 . In some embodiments, please refer to FIG. 3 , the wafer cleaning system 100 may be a cleaning system for a post-CMP cleaning process.

In some embodiments, the number of wafer cleaning brushes 102 may be two, and the two wafer cleaning brushes 102 are disposed on opposite sides of the wafer W, thereby cleaning the front and back sides of the wafer W respectively. In the working state, the wafer cleaning brush 102 contacts the surface of the wafer W. For example, in the working state, the wafer cleaning brush 102 will move from the initial position to the working position, so that the wafer cleaning brush 102 contacts the surface of the wafer W (as shown in FIG. 2 ). In the non-working state, the wafer cleaning brush 102 is at the initial position, so that the wafer cleaning brush 102 does not touch the surface of the wafer W (as shown in FIG. 2 ).

In some embodiments, the wafer cleaning brush 102 is shaped like a roller, for example. The material of the wafer cleaning brush 102 is, for example, foam or polyvinyl acetate (PVA). In addition, the wafer cleaning brush 102 may include at least one protrusion 102a. The shape of protrusion 102a can be granular, strip, wave, spiral or its combination. In this embodiment, the wafer cleaning brush 102 includes a plurality of protrusions 102a as an example, and the shape of the protrusions 102a is granular as an example, but the present invention is not limited thereto.

In addition, the wafer cleaning system 100 may further include a core 108 . The wafer cleaning brush 102 is sleeved on the core 108 . Thereby, the core body 108 can drive the wafer cleaning brush 102 to rotate. The core 108 may be hollow and may have a plurality of holes 108a (FIG. 2). In addition, the number of cores 108 may be the same as the number of wafer cleaning brushes 102 .

A cleaning solution 104 is provided to the surface of the wafer W. As shown in FIG. The cleaning solution 104 has conductivity. In some embodiments, the cleaning solution 104 may be an alkaline cleaning solution, such as ammonia solution.

In addition, the wafer cleaning system 100 may further include at least one of a cleaning solution supply device 110 and a cleaning solution supply device 112 . In some embodiments, the cleaning solution 104 may be provided to the surface of the wafer W by at least one of the cleaning solution supply device 110 and the cleaning solution supply device 112 .

The cleaning solution supply device 110 is disposed outside the core body 108 and communicated with the core body 108 to inject the cleaning solution 104 into the core body 108 . For example, the cleaning solution supply device 110 can inject the cleaning solution 104 into the core 108 through the pipeline 110 a ( FIG. 1 ). In addition, the cleaning solution 104 can pass through the holes 108 a ( FIG. 2 ) of the core 108 and the wafer cleaning brush 102 to reach the surface of the wafer W. Referring to FIG.

The cleaning solution supply device 112 is disposed above the wafer cleaning brush 102 . The cleaning solution supply device 112 sprays the cleaning solution 104 onto the surface of the wafer W. For example, the cleaning solution supply device 112 can be a spray bar, and the cleaning solution supply The processing device 112 can spray the cleaning solution 104 onto the surface of the wafer W through the nozzle 112a. In some embodiments, the cleaning solution supply device 112 can provide the cleaning solution 104 to the surface of the wafer W continuously. In some embodiments, the number of cleaning solution supply devices 112 may be two, and the two cleaning solution supply devices 112 are disposed on opposite sides of the wafer W. Referring to FIG.

In some embodiments, the cleaning solution 104 provided by the cleaning solution supply device 110 and the cleaning solution 104 provided by the cleaning solution supply device 112 may be the same cleaning solution, but the invention is not limited thereto. In other embodiments, the cleaning solution 104 provided by the cleaning solution supply device 110 and the cleaning solution 104 provided by the cleaning solution supply device 112 may be different cleaning solutions. In addition, the cleaning solution 104 provided by the cleaning solution supply device 110 and the cleaning solution 104 provided by the cleaning solution supply device 112 can be mixed on the surface of the wafer W. Referring to FIG.

Although the device for supplying the cleaning solution 104 to the surface of the wafer W is described by taking the above-mentioned devices (eg, the cleaning solution supply device 110 and/or the cleaning solution supply device 112 ) as an example, the invention is not limited thereto. Any device that can provide the cleaning solution 104 to the surface of the wafer W falls within the scope of the present invention.

The negative voltage generator 106 provides a negative voltage to the cleaning solution 104, thereby effectively preventing metals on the wafer W (eg, tungsten, aluminum, copper or gallium, but the invention is not limited thereto) from being dissociated during the cleaning process. In some embodiments, the electrode 106 a of the negative voltage generator 106 can be disposed inside the core 108 (as shown in FIG. 1 ) to provide a negative voltage to the cleaning solution 104 . In this embodiment, the two pairs of electrodes 106a of the negative voltage generator 106 can be arranged inside the core 108 on one side of the wafer W and on the wafer W respectively. The interior of the core 108 on the other side of the circle W. In some embodiments, the electrode 106 a of the negative voltage generator 106 may be disposed inside the cleaning solution supply device 112 (eg, spray bar) (as shown in FIG. 1 ) to provide a negative voltage to the cleaning solution 104 . Although the arrangement of the electrode 106a of the negative voltage generator 106 is an example of the above arrangement, the present invention is not limited thereto. As long as the electrode 106 a of the negative voltage generator 106 is configured to provide negative voltage to the cleaning solution 104 , it falls within the scope of the present invention. In addition, the negative voltage generator 106 can supply power to the electrode 106a through the wire 106b (as shown in FIG. 1 ).

In addition, the wafer cleaning system 100 may further include a roller 114 . In the working state, the roller 114 touches the edge of the wafer W. Thereby, the roller 114 can drive the wafer W to rotate. The number of rollers 114 can be adjusted according to requirements, and is not limited to the number shown in the figure.

Based on the above embodiments, in the wafer cleaning system 100, since the negative voltage generator 106 can be used to provide a negative voltage to the cleaning solution 104 during the cleaning process, the metal on the wafer W can be effectively prevented from being dissociated during the cleaning process. In this way, the problem of open circuit can be effectively prevented, thereby improving the yield rate.

FIG. 3 is a flowchart of a wafer cleaning method according to an embodiment of the present invention. Hereinafter, in addition, the wafer cleaning method of FIG. 3 can be implemented by the wafer cleaning system 100 of the above embodiment, but the wafer cleaning system for implementing the wafer cleaning method of the present invention is not limited thereto. In addition, for details about the wafer cleaning system 100 , reference may be made to the description of the above-mentioned embodiments, which will not be further described here. In addition, the wafer cleaning method of this embodiment can be used in a cleaning process after chemical mechanical polishing.

Referring to FIG. 1 to FIG. 3 , step S100 is performed to provide a cleaning solution 104 to the surface of the wafer W, wherein the cleaning solution 104 has conductivity. In some embodiments, the cleaning solution 104 can be injected into the core 108 by the cleaning solution supply device 110, and the cleaning solution 104 can pass through the holes 108a ( FIG. 2 ) of the core 108 and the wafer cleaning brush 102 to reach the surface of the wafer W, thereby providing the cleaning solution 104 to the surface of the wafer W. In some embodiments, the cleaning solution 104 may be sprayed onto the surface of the wafer W by a cleaning solution supply device 112 (eg, a spray bar). Although the method of providing the cleaning solution 104 to the surface of the wafer W is described by taking the above method as an example, the present invention is not limited thereto. Any method that can provide the cleaning solution 104 to the surface of the wafer W falls within the scope of the present invention.

Next, step S102 is performed, using the wafer cleaning brush 102 and the cleaning solution 104 to perform a cleaning process on the surface of the wafer W, wherein in the cleaning process, the negative voltage generator 106 is used to provide a negative voltage to the cleaning solution 104 . In some embodiments, when using the wafer cleaning brush 102 and the cleaning solution 104 to clean the surface of the wafer W, the core 108 can drive the wafer cleaning brush 102 to clean the surface of the wafer W, and the roller 114 can drive the wafer W to rotate, thereby cleaning the entire surface of the wafer W. Meanwhile, the negative voltage generator 106 is used to provide a negative voltage to the cleaning solution 104 to prevent metals on the wafer W (eg, tungsten, aluminum, copper or gallium, but the invention is not limited thereto) from being dissociated during the cleaning process.

In some embodiments, the electrode 106 a of the negative voltage generator 106 can be disposed inside the core 108 (as shown in FIG. 1 ) to provide a negative voltage to the cleaning solution 104 . In some embodiments, the electrode 106a of the negative voltage generator 106 can be set to clean The interior of the solution supply device 112 (eg, spray bar) (as shown in FIG. 1 ) to provide a negative voltage to the cleaning solution 104 . Although the method for providing the negative voltage to the cleaning solution 104 is the above method as an example, the invention is not limited thereto. Any method that can provide a negative voltage to the cleaning solution 104 falls within the scope of the present invention.

Based on the above embodiments, in the above wafer cleaning method, since the negative voltage generator 106 can be used to provide a negative voltage to the cleaning solution 104 during the cleaning process, the metal on the wafer W can be effectively prevented from being dissociated during the cleaning process. In this way, the problem of open circuit can be effectively prevented, thereby improving the yield rate.

To sum up, the wafer cleaning system and wafer cleaning method of the above embodiments can effectively prevent the metal on the wafer from being dissociated during the cleaning process, thereby effectively preventing the disconnection problem and improving the yield.

Although the present invention has been disclosed as above with the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the appended patent application as the criterion.

100: Wafer cleaning system

102: Wafer cleaning brush

102a: Protrusion

104: cleaning solution

106: Negative voltage generator

106a: electrode

106b: wire

108: Core

110, 112: cleaning solution supply device

110a: pipeline

112a: Nozzle

114:Roller

W: Wafer

Claims (10)

A wafer cleaning system for cleaning a wafer, and comprising: a wafer cleaning brush, wherein in an operating state, the wafer cleaning brush contacts the surface of the wafer; a cleaning solution provided to the surface of the wafer, wherein the cleaning solution has conductivity; and a negative voltage generator that provides a negative voltage to the cleaning solution, wherein the cleaning solution supplied with the negative voltage directly contacts the surface of the wafer. The wafer cleaning system according to claim 1, wherein the number of the wafer cleaning brushes is two, and the two wafer cleaning brushes are arranged on opposite sides of the wafer. The wafer cleaning system according to claim 1, further comprising: a core body, wherein the wafer cleaning brush is sleeved on the core body, wherein the core body is hollow and has a plurality of holes, and the electrodes of the negative voltage generator are arranged inside the core body. The wafer cleaning system according to claim 3, further comprising: a cleaning solution supply device disposed outside the core and connected to the core to inject the cleaning solution into the core. The wafer cleaning system according to claim 1, further comprising: a cleaning solution supply device, arranged above the wafer cleaning brush, and spraying the cleaning solution onto the surface of the wafer, and the electrode of the negative voltage generator is arranged inside the cleaning solution supply device. The wafer cleaning system according to claim 1, further comprising: a roller, wherein in a working state, the roller contacts the edge of the wafer. A wafer cleaning method, comprising: providing a cleaning solution to a surface of a wafer, wherein the cleaning solution has conductivity; and performing a cleaning process on the surface of the wafer using a wafer cleaning brush and the cleaning solution, wherein in the cleaning process, a negative voltage generator is used to provide a negative voltage to the cleaning solution, and the cleaning solution provided with the negative voltage directly contacts the surface of the wafer. The wafer cleaning method according to claim 7, wherein the wafer cleaning brush is sleeved on a core body, wherein the core body is hollow and has a plurality of holes, and the electrodes of the negative voltage generator are arranged inside the core body. The wafer cleaning method as described in claim 8, wherein the method for providing the cleaning solution to the surface of the wafer comprises: injecting the cleaning solution into the core body by a cleaning solution supply device, and the cleaning solution passes through a plurality of the holes of the core body and the wafer cleaning brush to reach the surface of the wafer. The wafer cleaning method according to claim 7, wherein the method of providing the cleaning solution to the surface of the wafer comprises: spraying the cleaning solution onto the surface of the wafer by a cleaning solution supply device, wherein the electrode of the negative voltage generator is arranged inside the cleaning solution supply device.

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