Wafer transport method and wafer transport device

Abstract

To provide a wafer transport method and a wafer transport device that can suppress the adhesion of rubber microparticles to wafers during wafer transport without significantly reducing productivity.SOLUTION: A wafer transport method according to the present invention is a method of holding and transporting a wafer on a polishing apparatus using a wafer transport device equipped with a holding portion that holds the wafer surface, and the wafer is held and transported by the holding portion in a state where an anti-adhesion chemical liquid is applied to at least the surface of the holding portion that comes into contact with the wafer. The wafer transport device according to the present invention includes a holding portion that holds the wafer surface and a chemical liquid application portion that applies an anti-adhesion chemical liquid to at least the surface of the holding portion that comes into contact with the wafer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wafer transport method and a wafer transport device. [Background technology]

[0002] Conventionally, when wafers are automatically transported after polishing, the wafers are held by vacuum suction using suction rubber of a wafer transport device (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-113985 Summary of the Invention [Problem to be solved by the invention]

[0004] However, after wafers are transported using this method, rubber particles from the suction rubber adhere to the wafer surface, which can be detected as suction marks during the LPD (Light Point Defect) inspection process. These rubber particles can potentially reduce yield in the semiconductor device manufacturing process. Furthermore, these suction marks are particularly likely to occur when the suction rubber is replaced with a new one.

[0005] To address this issue, conventional countermeasures have been taken, such as performing dummy running until the rubber particles derived from the adsorbed rubber no longer adhere to the wafer, but this has the problem of reducing productivity.

[0006] The present invention aims to provide a wafer transport method and a wafer transport device that can prevent rubber fine particles from adhering to wafers during wafer transport without significantly reducing productivity. [Means for solving the problem]

[0007] The gist and configuration of the present invention are as follows. (1) A wafer transport method for holding and transporting a wafer on a polishing apparatus using a wafer transport apparatus having a holding part for holding a wafer surface, comprising: A wafer transport method, characterized in that the wafer is held and transported by the holding part in a state where an adhesion preventive chemical liquid is applied to at least the surface of the holding part that comes into contact with the wafer.

[0008] (2) The adhesion prevention chemical solution is an aqueous solution of a water-soluble polymer, The wafer transport method according to (1) above, wherein the water-soluble polymer is one or more selected from the group consisting of hydroxyethyl cellulose (HEC), polyethylene glycol (PEG), and polypropylene glycol (PPG).

[0009] (3) The wafer transport method according to (1) or (2), wherein the application of the adhesion prevention chemical solution is carried out periodically or at appropriate times.

[0010] (4) The wafer transport device includes a spray nozzle for spraying the adhesion preventive chemical solution, The wafer transport method according to any one of (1) to (3), wherein the application of the adhesion preventive chemical liquid is performed by the spray nozzle spraying the adhesion preventive chemical liquid onto the holder.

[0011] (5) The wafer transport device includes a chemical tank for storing the adhesion prevention chemical solution, The wafer transport method described in any one of (1) to (3), wherein the application of the adhesion prevention liquid is performed by immersing the holding part in the adhesion prevention liquid stored in the chemical tank.

[0012] (6) a holder for holding the wafer surface; a chemical liquid application unit that applies an adhesion prevention chemical liquid to at least the surface of the holding unit that comes into contact with the wafer.

[0013] (7) The wafer transport device according to (6), wherein the chemical applying unit is a spray nozzle that sprays the adhesion prevention chemical.

[0014] (8) The wafer transport device according to (6), wherein the chemical applying unit is a chemical tank that stores the adhesion prevention chemical. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a wafer transport method and a wafer transport device that can prevent rubber fine particles from adhering to wafers during wafer transport without significantly reducing productivity. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a side view schematically showing a wafer transport device according to an embodiment of the present invention; [Figure 2] FIG. 10 is a side view schematically showing a wafer transport device according to another embodiment of the present invention. [Figure 3] FIG. 10 is a diagram showing the results of adhesion of rubber to a wafer in a conventional example. [Figure 4] An enlarged view of the adhered rubber. [Figure 5] FIG. 10 is a diagram showing the results of adhesion of rubber to a wafer in an example of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. For convenience of explanation, an embodiment of a wafer transport device will be described first.

[0018] <Wafer transport device> Fig. 1 is a side view showing a wafer transport device according to one embodiment of the present invention. As shown in Fig. 1, this wafer transport device 10 includes a holder (handler) 11 that holds the wafer surface, and a chemical liquid applicator 16 that applies an adhesion preventative chemical liquid 15 to at least a surface 13c of the holder 11 that comes into contact with the wafer.

[0019] As shown in Fig. 1, the holder 11 comprises a disk-shaped main body 12 and an adsorption part 13 attached to the underside of the main body 12. The adsorption part 13 comprises a support part 13a extending in the vertical direction in the figure, and an adsorption rubber part 13b (made of silicone rubber, for example) having a surface 13c that comes into contact with the wafer. Although two adsorption parts 13 are shown in the figure, it is preferable that the adsorption parts 13 are arranged in a number and positions sufficient to adsorb and hold the wafer.

[0020] In the example of FIG. 1, the holding unit 11 further includes a carrier adsorption unit 14 that adsorbs and holds the surface of the carrier plate. As shown in the figure, the carrier adsorption unit 14 is located on the outer periphery of the main body 12 relative to the adsorption unit 13. The carrier adsorption unit 14 is composed of a support unit 14a that extends vertically in the figure and an adsorption rubber unit 14b (made of silicone rubber, for example) that has a surface that comes into contact with the carrier plate. Although two carrier adsorption units 14 are shown in the figure, it is preferable that the carrier adsorption units 14 be located in a number and positions sufficient to hold the carrier plate.

[0021] In the embodiment of FIG. 1 , the chemical solution applicator 16 is a spray nozzle that sprays the adhesion preventive chemical solution 15. When spraying the adhesion preventive chemical solution 15, the holding unit 11 (surface 13c) can be moved to the position of the spray nozzle, or the spray nozzle can be moved to the position of the holding unit 11 (surface 13c). From the viewpoint of improving work efficiency, it is preferable to provide one spray nozzle for each suction unit 13 (a total of two within the illustrated range) and apply the adhesion preventive chemical solution 15 to all suction units 13 in a single application, as in the illustrated example. Alternatively, a configuration may be adopted in which the adhesion preventive chemical solution 15 is applied to all suction units 13 by performing application multiple times using fewer spray nozzles than the number of suction units 13 (for example, a total of one). Furthermore, to ensure that the adhesion preventive chemical solution 15 is applied to the suction units 13, multiple spray nozzles may be provided for each suction unit 13.

[0022] The adhesion prevention liquid 15 may be any liquid that, when applied to the surface 13c, makes it difficult for rubber to adhere to the surface 13c. The adhesion prevention liquid 15 is preferably an aqueous solution of a water-soluble polymer, and in particular, the water-soluble polymer is preferably one or more selected from hydroxyethyl cellulose (HEC), polyethylene glycol (PEG), and polypropylene glycol (PPG). Other examples of the adhesion prevention liquid 15 include alcohols with relatively high viscosity, such as glycerin.

[0023] Fig. 2 is a side view schematically showing a wafer transport device according to another embodiment of the present invention. In the example shown in Fig. 2, this wafer transport device 20 also includes a holder (handler) 21 that holds the wafer surface, and a chemical liquid applicator 26 that applies an adhesion preventative chemical liquid 25 to at least a surface 23c of the holder 21 that comes into contact with the wafer.

[0024] 2, the holding part 21 comprises a disc-shaped main body part 22 and an adsorption part 23 attached to the underside of the main body part 22. The adsorption part 23 comprises a support part 23a extending in the vertical direction in the figure and an adsorption rubber part 23b (made of silicone rubber, for example) having a surface 23c that comes into contact with the wafer. Although two adsorption parts 23 are shown in the figure, it is preferable that the adsorption parts 23 be arranged in a number and positions sufficient to adsorb and hold the wafer.

[0025] In the example of FIG. 2, the holding unit 21 further includes a carrier adsorption unit 24 that adsorbs and holds the surface of the carrier plate. As shown in the figure, the carrier adsorption unit 24 is disposed on the outer periphery of the adsorption unit 23. The carrier adsorption unit 24 is composed of a support unit 24a that extends vertically in the figure and an adsorption rubber unit 24b that has a surface that comes into contact with the carrier plate. Although two carrier adsorption units 24 are shown in the figure, it is preferable that the carrier adsorption units 24 be disposed in a number and positions sufficient to hold the carrier plate.

[0026] In the embodiment of FIG. 2, the chemical liquid application unit 26 is a chemical liquid tank that stores the adhesion prevention chemical liquid 25. In the illustrated example, one chemical liquid tank is provided for each of the adsorption units 23. By providing such a chemical liquid tank, the surface 23c can be immersed in the adhesion prevention chemical liquid 25 by immersing the holding unit 21 in the adhesion prevention chemical liquid 25 stored in the chemical liquid tank. When immersing the adhesion prevention chemical liquid 25 into the surface 23c, the holding unit 21 (surface 23c) can be moved to the position of the chemical liquid tank, or the chemical liquid tank can be moved to the position of the holding unit 21 (surface 23c).

[0027] The adhesion prevention chemical 25 is the same as in the embodiment of FIG. 1, so a repeated explanation will be omitted.

[0028] In the above embodiments, examples in which the chemical application unit is a spray nozzle and an example in which the chemical application unit is a chemical tank are shown, but the chemical application unit is not limited to these examples as long as it can apply the anti-adhesion chemical to at least the surface of the holder that comes into contact with the wafer. The chemical application unit can also be, for example, a brush or a sheet coated with the anti-adhesion chemical.

[0029] <Wafer transport method> A wafer transport method according to one embodiment of the present invention is a wafer transport method in which a wafer is held and transported from a polishing apparatus using a wafer transport device having a holder that holds the wafer surface. As the wafer transport device, for example, the wafer transport device 10 (20) of the embodiment shown in FIG. 1 or FIG. 2 can be used. Details of the wafer transport device have already been described in the embodiment of the wafer transport device, so a repeated description will be omitted.

[0030] In the method of this embodiment, the wafer is held and transported by the holding part 11 (21) with an anti-adhesion chemical solution 15 (25) applied to at least the surface 13c (23c) of the holding part 11 (21) that comes into contact with the wafer.

[0031] As described in the embodiment of Figure 1, as an example, the wafer transport device 10 can be equipped with a spray nozzle that sprays the anti-adhesion liquid 15, and it is preferable that the application of the anti-adhesion liquid 15 is performed by the spray nozzle spraying the anti-adhesion liquid 15 onto the holding portion 11 (surface 13c).

[0032] As described in the embodiment of Figure 2, as another example, the wafer transport device 20 can be provided with a chemical tank for storing the adhesion prevention chemical liquid 25, and it is also preferable that the adhesion prevention chemical liquid 25 is applied by immersing the holding part 21 in the adhesion prevention chemical liquid 25 stored in the chemical tank.

[0033] As described above, the adhesive agent may be applied to the holder (the surface that comes into contact with the wafer surface) using a brush or a sheet coated with the adhesive agent. In the case of a brush, the adhesive agent can be applied by immersing the brush in the adhesive agent and then using the brush after immersion to apply the adhesive agent to the holder. In the case of a sheet, the surface of the sheet coated with the adhesive agent can be attached to the holder (the surface that comes into contact with the wafer surface) and then the sheet can be removed.

[0034] As with the wafer transport device, the adhesion prevention liquid may be any liquid that, when applied to the surface that comes into contact with the wafer surface, makes it difficult for rubber to adhere to that surface. The adhesion prevention liquid is preferably an aqueous solution of a water-soluble polymer, and in particular, the water-soluble polymer is preferably one or more selected from hydroxyethyl cellulose (HEC), polyethylene glycol (PEG), and polypropylene glycol (PPG). Other examples of the adhesion prevention liquid include relatively high-viscosity alcohols such as glycerin.

[0035] In the method of this embodiment, it is preferable to apply the adhesion prevention liquid periodically or at appropriate times. The effects of the embodiments of the present invention will be described below.

[0036] First, regarding an embodiment of a wafer transport device, the wafer transport device 10 (20) of the embodiment shown in Figures 1 and 2 includes a holding unit 11 (21) that holds the wafer surface, and a chemical liquid application unit 16 (26) that applies an anti-adhesion chemical liquid 15 (25) to at least the surface 13c (23c) of the holding unit 11 (21) that comes into contact with the wafer. 1 and 2, the wafer transport device 10 (20) can apply the adhesion preventive chemical 15 (25) to at least the surface 13c (23c) of the holder 11 (21) that comes into contact with the wafer by the chemical liquid applicator 16 (26), and when transporting the wafer, the wafer can be transported in a state where the adhesion preventive chemical 15 (25) has been applied to at least the surface 13c (23c) of the holder 11 (21) that comes into contact with the wafer. Therefore, when transporting the wafer, the wafer surface and the surface 13c (23c) do not come into direct contact with each other but come into contact via the adhesion preventive chemical 15 (25), making it difficult for rubber to adhere to the wafer, and thus preventing rubber microparticles from adhering to the wafer. Furthermore, when applying an anti-adhesion liquid to a wafer, it is possible to apply it to the entire surface so that any position can be adsorbed, but compared to such a case, the amount of anti-adhesion liquid used can be reduced and the entire wafer surface can be prevented from being modified. Furthermore, since there is no need for dummy running, productivity is improved.

[0037] In the wafer transport device of the present disclosure, as in the embodiment of Fig. 1, the chemical liquid application unit 16 is preferably a spray nozzle that sprays the adhesion prevention chemical liquid 15. In the embodiment of Fig. 2, if the adhesion prevention chemical liquid 25 in the chemical liquid tank becomes contaminated, there is a risk that the suction rubber part 23b will be contaminated by the adhesion prevention chemical liquid 25. Therefore, it is preferable to periodically replace the adhesion prevention chemical liquid 25, and as a result, a large amount of the adhesion prevention chemical liquid 25 will be required. On the other hand, the embodiment of Fig. 1 is advantageous in that it is not necessary to replace the adhesion prevention chemical liquid 15, and the amount of adhesion prevention chemical liquid 15 used can be reduced.

[0038] In the wafer transport device of the present disclosure, as in the embodiment of Fig. 2, the chemical solution application unit 26 is preferably a chemical solution tank that stores the adhesion preventive chemical solution 25. The embodiment of Fig. 2 is advantageous in that uneven application of the adhesion preventive chemical solution 25 can be suppressed.

[0039] In the wafer transport device of the present disclosure, the adhesion prevention chemical solution 15 (25) is an aqueous solution of a water-soluble polymer, and the water-soluble polymer is preferably one or more selected from hydroxyethyl cellulose (HEC), polyethylene glycol (PEG), and polypropylene glycol (PPG), because this is highly effective in preventing rubber from adhering to the wafer and has little effect on the wafer (such as modification of the wafer surface).

[0040] Next, the wafer transport method of this embodiment is a wafer transport method in which a wafer on a polishing device is held and transported using a wafer transport device 10 (20) equipped with a holding part 11 (21) that holds the wafer surface, and the wafer is held and transported by the front holding part 11 (21) in a state in which an anti-adhesion chemical liquid 15 (25) is applied to at least the surface 13c (23c) of the holding part 11 (21) that comes into contact with the wafer. According to the wafer transport method of this embodiment, the front holding unit 11 (21) holds and transports the wafer while applying the adhesion prevention liquid 15 (25) to at least the surface 13c (23c) of the holding unit 11 (21) that contacts the wafer. Therefore, during wafer transport, the wafer surface and the surface 13c (23c) do not come into direct contact with each other, but rather contact each other via the adhesion prevention liquid 15 (25). This makes it difficult for rubber to adhere to the wafer, thereby reducing the adhesion of rubber particles to the wafer. Furthermore, compared to applying the adhesion prevention liquid to the entire wafer surface, which can be applied to any position, the amount of adhesion prevention liquid used can be reduced and the possibility of the entire wafer surface being modified can be reduced. Furthermore, productivity is improved because dummy runs are no longer necessary.

[0041] In the wafer transport method of the present disclosure, the adhesion prevention chemical liquid is an aqueous solution of a water-soluble polymer, and the water-soluble polymer is preferably one or more selected from hydroxyethyl cellulose (HEC), polyethylene glycol (PEG), and polypropylene glycol (PPG), because this is highly effective in preventing adhesion of rubber to the wafer and has little effect on the wafer (such as modification of the wafer surface).

[0042] In the wafer transport method of the present disclosure, it is preferable to apply the adhesion preventive liquid periodically or at an appropriate time, because the adhesion preventive liquid dries up, and by applying the adhesion preventive liquid periodically or at an appropriate time in this manner, it becomes difficult for rubber to adhere to the wafer, and the effect of suppressing the formation of rubber adhesion marks on the wafer can be more reliably achieved.

[0043] In the wafer transport method of the present disclosure, it is preferable that the wafer transport device 10 (used) is equipped with a spray nozzle for spraying the adhesion preventive chemical 15, and that the adhesion preventive chemical 15 is applied by the spray nozzle spraying the adhesion preventive chemical 15 onto the holder 11. This method is advantageous in that the amount of adhesion preventive chemical 15 used can be reduced.

[0044] In the wafer transport method of the present disclosure, it is also preferable that the wafer transport device 20 (used) is provided with a chemical tank for storing the adhesion preventive chemical 25, and that the adhesion preventive chemical 25 is applied by immersing the holder 21 in the adhesion preventive chemical 25 stored in the chemical tank. This method is advantageous in that it can prevent uneven application of the adhesion preventive chemical 25.

[0045] 1 and 2, it is preferable not to apply the adhesion prevention chemical 15 (25) to the carrier adsorption portion 14 (24). Because application of the adhesion prevention chemical 15 (25) makes the carrier plate more likely to slip, it is preferable for the carrier adsorption portion 14 (24) to be able to adsorb and hold the carrier plate without slipping, even if adhesion marks do not cause any major problems. However, the adhesion prevention chemical 15 (25) can also be applied to the carrier adsorption portion 14 (24). Note that slippage caused by application of the adhesion prevention chemical 15 (25) to the holder 11 (21) is not enough to interfere with adsorption and holding of the wafer. [Example]

[0046] In order to confirm the effects of the present invention, the suction marks on the wafers were compared between a conventional example in which wafers were transported using suction rubber parts immediately after they had been replaced with new ones, and an inventive example in which wafers were transported with the suction rubber parts replaced with new ones and then coated with an anti-adhesion chemical solution using the method shown in Figure 1.

[0047] The wafer used was a 300 mm diameter p-type silicon wafer. The adhesive rubber part was made of silicone rubber. The anti-adhesion chemical solution used was an aqueous solution of hydroxyethyl cellulose (HEC).

[0048] Figure 3 shows the results of rubber adhesion to wafers in a conventional example. Figure 3 shows an overlaid LPD map of one batch of five wafers. As shown in Figure 3, LPDs were clearly visible as suction marks in the conventional example. Figure 4 is an enlarged view of the adhered rubber. SEM observation images show this type of adhesion on the wafer. When this adhesion was analyzed using Raman spectroscopy, "polydimethylsiloxane," a type of silicone, was detected.

[0049] Figure 5 shows the results of rubber adhesion to wafers in the inventive example. Figure 5 shows the overlaid LPD map of one batch of five wafers. As shown in Figure 5, the inventive example shows a reduction in LPD, which indicates rubber suction marks, compared to the conventional example. [Explanation of symbols]

[0050] 10: wafer transport device; 11: Holding part, 12: Main body, 13: Adsorption part, 14: Carrier adsorption part, 15: Anti-adhesion chemicals, 16: Chemical solution application part, 20: wafer transport device; 21: Holding part, 22: Main body, 23: Adsorption part, 24: Carrier adsorption part, 25: Anti-adhesion chemicals, 26: Chemical solution application section

Claims

1. A wafer transport method for holding and transporting a wafer on a polishing apparatus using a wafer transport apparatus having a holding part for holding a wafer surface, comprising: A wafer transport method, characterized in that the wafer is held and transported by the holding part in a state where an adhesion preventive chemical solution is applied to at least the surface of the holding part that comes into contact with the wafer.

2. The adhesion prevention chemical solution is an aqueous solution of a water-soluble polymer, 2. The wafer transport method according to claim 1, wherein the water-soluble polymer is at least one selected from the group consisting of hydroxyethyl cellulose (HEC), polyethylene glycol (PEG), and polypropylene glycol (PPG).

3. 3. The wafer transport method according to claim 1, wherein the application of the adhesion preventive chemical solution is carried out periodically or at appropriate times.

4. the wafer transport device includes a spray nozzle for spraying the adhesion preventive chemical solution; 3. The wafer transport method according to claim 1, wherein the application of the adhesion preventive chemical liquid is performed by spraying the adhesion preventive chemical liquid onto the holder using the spray nozzle.

5. the wafer transport device includes a chemical tank for storing the adhesion prevention chemical; 3. The wafer transport method according to claim 1, wherein the application of the adhesion preventive chemical liquid is performed by immersing the holder in the adhesion preventive chemical liquid stored in the chemical liquid tank.

6. a holder that holds the surface of the wafer; a chemical liquid application unit that applies an adhesion prevention chemical liquid to at least the surface of the holding unit that comes into contact with the wafer.

7. 7. The wafer transport device according to claim 6, wherein the chemical applying unit is a spray nozzle that sprays the adhesion preventive chemical.

8. 7. The wafer transport device according to claim 6, wherein the chemical applying unit is a chemical tank that stores the adhesion prevention chemical liquid.

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