JP2004265906A - Method of manufacturing semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer manufacturing method capable of reducing particles attached to the surface of a semiconductor wafer such as a silicon wafer or the like, and preventing the semiconductor wafer from being locally etched. <P>SOLUTION: The semiconductor wafer manufacturing method comprises a finishing polish process of feeding a polishing agent to a polishing cloth as the polishing cloth stuck on a surface plate is rotated, and carrying out finishing polish by sliding the semiconductor wafer on the polishing cloth as it is brought into close contact with the cloth; and a cleaning process of introducing the semiconductor wafer subjected to the finishing polish process into a cleaning tank for cleaning. After the semiconductor wafer is subjected to the finishing polish process, the semiconductor wafer is introduced into the cleaning tank within 40 seconds. Or, a drizzle shower of water or a water shower of low pressure is applied on the semiconductor wafer subjected to the finishing polish process, and then the semiconductor wafer is introduced into the cleaning tank as its surface is coated with the polishing agent. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor wafer such as a silicon wafer (hereinafter sometimes simply referred to as “wafer”), and more particularly to a process from a finish polishing step to a cleaning step.
[0002]
[Prior art]
Conventionally, silicon wafers have been manufactured as semiconductor substrate materials used for memory devices and the like. The production of a silicon wafer is mainly performed by a single crystal growth step of producing a single crystal ingot using a Czochralski (CZ) method, a floating zone melting (FZ) method, or the like, and a single crystal ingot. Is sliced and at least one principal surface is mirror-finished. Then, in the device manufacturing process, a device is formed on the main surface of the mirror-finished wafer.
[0003]
The wafer manufacturing (processing) process will be described in more detail. A slice process of slicing a single crystal ingot to obtain a thin disk-shaped wafer, and an outer peripheral portion of the wafer obtained by the slicing process in order to prevent cracking and chipping of the wafer. Chamfering step, lapping step for flattening the wafer, etching step for removing processing distortion remaining on the chamfered and wrapped wafer, and polishing (polishing) step for polishing the surface of the wafer to make it mirror-finished And a cleaning step for removing abrasives and foreign matter adhering to the polished wafer surface. Note that these steps show main steps, and there may be cases where a heat treatment step is added, the order of the steps is changed, or the same step is performed in multiple stages. For example, in the polishing step, it is usual to carry out polishing of about three stages of primary, secondary and finishing, and the cleaning step is also performed in a plurality of stages such as primary cleaning and finish cleaning.
[0004]
In the polishing step, an abrasive (polishing liquid) is supplied to the polishing cloth while rotating the polishing cloth attached to the platen using a polishing apparatus, and the etched silicon wafer is brought into contact with the polishing cloth at an appropriate pressure ( (Sliding contact) and polishing. At this time, an alkaline solution containing colloidal silica is generally used as a polishing agent. By supplying such a polishing agent to the contact surface between the polishing cloth and the silicon wafer, the polishing agent and the silicon wafer cause a mechanochemical action, and the polishing proceeds.
[0005]
Various types of polishing apparatuses are used, for example, a batch type apparatus in which a plurality of wafers are held on one polishing head (polishing plate) or one wafer per polishing head. Wafer type that holds and polish the wafer. Also, there are various types of wafer holding methods, such as a method of holding by vacuum suction, a method of attaching with wax, and a method of attaching using the surface tension of water.
[0006]
At present, an apparatus 31 having a configuration as shown in FIG. 7 is mainly used. In this polishing apparatus 31, a plurality of wafers W are attached to a polishing plate 33 using wax, the polishing cloth 32 attached to the surface plate 30 is rotated, and an abrasive 39 is supplied from the polishing liquid supply nozzle 34 onto the polishing cloth 32. Supply. By bringing the wafer W into sliding contact with the polishing cloth in this manner, one side of the wafer can be mirror-finished.
The above-described polishing apparatus 31 is a so-called single-side polishing apparatus for polishing a wafer one surface at a time, but includes upper and lower platens, and sandwiches the wafer with upper and lower polishing cloths attached to each platen. There is also a double-side polishing apparatus for polishing both sides simultaneously.
[0007]
The surface of the wafer after being polished as described above becomes an active surface (hydrophobic), and fine particles (particles) easily adhere thereto. If particles adhere to the surface of the wafer, the yield in the device manufacturing process decreases. Therefore, it is necessary to reduce the adhesion of particles to the wafer surface and to remove the adhered particles.
In addition, if the abrasive or the like adhering to the wafer polishing surface (active surface) immediately after the final polishing is dried and solidified, it becomes difficult to remove the abrasive and other foreign substances on the surface in the next cleaning step. .
[0008]
Therefore, conventionally, in order to prevent the polishing agent from drying or the like, the wafer surface is kept in a wet state, and showering is performed between the polishing step and the cleaning step. FIG. 5 shows a flow of work performed from a conventional polishing process to a cleaning process. For example, when polishing is performed by attaching a wafer to a plate with wax, after the polishing is completed, the wafer is peeled off from the plate, temporarily stored in a cassette, and stored in a water tank (stock tank) called storage water. Thereafter, the wafer is transported to a cleaning step, where cleaning (primary cleaning) is performed. Then, during each of these storing, storing, and transporting steps, a constant water pressure is applied to the wafer from the shower body 11 as shown in FIG. 6 (for example, several MPa to 10 MPa for a nozzle diameter of 0.1 to 20 mm). The showering is performed by spraying the pure water 12 in ().
[0009]
[Problems to be solved by the invention]
By performing showering as described above, the abrasive is partially or entirely removed from the surface of the wafer, and thereafter, even if the cleaning process is performed, many particles remain on the surface of the wafer, There is a problem that the surface roughness is deteriorated due to a typical etching action, and the yield in the device manufacturing process is reduced.
[0010]
Accordingly, an object of the present invention is to provide a wafer manufacturing method capable of reducing adhesion of particles to the surface of a semiconductor wafer such as a silicon wafer and preventing local etching.
[0011]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, at least, an abrasive is supplied to the polishing cloth while rotating the polishing cloth attached to the surface plate, and a semiconductor wafer is brought into sliding contact with the polishing cloth. In a method of manufacturing a semiconductor wafer having a final polishing step of performing final polishing, and a cleaning step of performing cleaning by putting the semiconductor wafer subjected to final polishing into a cleaning tank, within 40 seconds after the final polishing of the semiconductor wafer A method for manufacturing a semiconductor wafer is provided, wherein the semiconductor wafer is charged into the cleaning tank (claim 1).
[0012]
As described above, if the time until the start of the cleaning (primary cleaning) after the end of the final polishing is set to 40 seconds or less, particles hardly adhere during that time regardless of whether the shower cleaning is performed or not. Abrasives and the like are also removed from the surface in the cleaning step. This makes it possible to manufacture a clean wafer having extremely little adhesion of abrasives and particles (remaining after washing) and having no portion that deteriorates the surface roughness due to local etching. Further, since the time from polishing to cleaning is shortened, there is an advantage that the entire manufacturing time is shortened and the productivity is improved.
[0013]
Note that the time from the final polishing to the cleaning varies depending on the process during the process, and particularly on the type of the polishing process, and the particles may not increase so much even if it takes more than 40 seconds. However, when particles are likely to be generated, for example, when a simple cleaning mechanism is present in the polishing apparatus itself, time management is particularly important. Time should be as short as possible. Therefore, in particular, if the time from the completion of the finish polishing to the introduction into the cleaning tank is set to 40 seconds or less, the generation of particles can be effectively suppressed regardless of any process or polishing apparatus.
[0014]
Further, according to the present invention, at least a polishing agent is supplied to the polishing pad while rotating the polishing pad attached to the surface plate, and a finish polishing is performed by bringing a semiconductor wafer into sliding contact with the polishing pad. In a method for manufacturing a semiconductor wafer having a polishing step and a cleaning step in which the finish-polished semiconductor wafer is put into a cleaning tank to perform cleaning, the surface of the finish-polished semiconductor wafer is covered with an abrasive. There is provided a method for manufacturing a semiconductor wafer, wherein the method is charged into the cleaning tank in a state (claim 2).
[0015]
In this way, if the semiconductor wafer that has been finish-polished is put into the cleaning tank with the surface covered with the abrasive, after polishing, the abrasive is applied like a protective film until it is put into the cleaning tank. Since the entire surface of the wafer is covered, it is possible to prevent particles from directly adhering to the surface of the wafer and to prevent a local etching action. Then, by removing the polishing agent and the like from the entire wafer in the cleaning step, a clean wafer with very little adhesion of particles and the like can be obtained.
Conventionally, it has been desired that the abrasive be removed as soon as possible after the polishing. However, after the final polishing, the abrasive is more likely to adhere to the surface of the wafer, so that particles can be prevented from adhering. The state in which the abrasive was adhered was maintained until the cleaning step.
[0016]
In these cases, after the semiconductor wafer is finish-polished, it may be directly charged into the cleaning tank (claim 3).
In other words, if the polished wafer is put directly into the cleaning tank without storing the stock tank and showering as in the past, the polishing agent ensures that the entire surface of the wafer is polished between the polishing step and the cleaning step. And functions like a protective film to prevent adhesion of particles. Further, the working time is shortened, and the productivity can be further improved.
[0017]
In addition, after the finish polishing step, before entering the cleaning step, the shower and the water pressure of the atomized water for the finish-polished semiconductor wafer are set to 0.25 MPa or less for a nozzle diameter of 0.1 to 20 mm. At least one type of low pressure shower may be provided (claim 4).
[0018]
In this way, if the semiconductor wafer that has been finish-polished is subjected to a mist shower or a low-pressure shower between the polishing step and the cleaning step, the abrasive covering the wafer surface is gradually removed, It is not possible to completely remove the abrasive partially, and it is possible to prevent the abrasive from drying. Therefore, since the polishing agent functions for a long time like the protective film, adhesion of particles is prevented. Also, at the stage of entering the cleaning step, the abrasive and polishing residue are not dried and are removed to some extent, so that the abrasive and the like on the wafer surface can be easily removed by cleaning, which is more efficient. Become.
[0019]
Further, in this case, it is preferable to use pure water containing particles having a size of 0.1 μm or more at 100 particles / liter or less as the water for showering (claim 5).
By performing a mist shower or a low-pressure shower using pure water containing a very small amount of fine particles as described above, the number of particles adhering to the wafer can be further reduced, and the extremely clean wafer after cleaning. Can be obtained.
[0020]
Hereinafter, the present invention will be described in more detail.
The present inventors have conducted intensive studies on the cause of a large number of particles remaining on the surface of the wafer and uneven etching even when the wafer that has been finish-polished is sufficiently cleaned when manufacturing a silicon wafer. went. After close examination, it was found that the main cause was that the polishing agent covering the surface of the wafer was partially removed after polishing and before the cleaning step.
[0021]
In other words, the abrasive covering the surface of the polishing wafer acts as a protective film for preventing the adhesion of particles, and the surface of the wafer is covered by shower conditions (water pressure, etc.) applied before the cleaning step. Part of the abrasive that has been removed is completely removed, and as a result, fine particles adhere to the portion where the abrasive has been removed, that is, the portion where the protective film has been removed, and cannot be completely removed in the cleaning process And the like.
Therefore, the present inventors have found that, after finishing polishing a wafer and before putting it into a cleaning tank, it is possible to manufacture an extremely clean wafer by preventing adhesion of particles, and to find out various conditions. Have completed the present invention.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the method for manufacturing a semiconductor wafer according to the present invention will be specifically described. In addition, as a preferred embodiment, a description will be given of a process from finishing polishing (hereinafter sometimes simply referred to as “polishing”) on a silicon wafer using a single-side polishing apparatus to cleaning.
[0023]
FIG. 1 shows a first embodiment of the present invention. As shown in FIG. 1, after the wafer is polished, the stock or the like in the storage water (stock tank), which has been conventionally performed, is omitted until the wafer is washed, and the finish-polished wafer is directly put into the washing tank. I do. At this time, although it depends on the polishing agent used, the present inventors have conducted a close inspection and found that the wafer adhered to the surface after 40 seconds after the wafer was detached from the polishing cloth and then put into the cleaning tank. It has been found that the abrasive may be dried or uneven etching may occur. Therefore, after the wafer is finish-polished, that is, after the wafer is separated from the polishing pad, the wafer is put into the cleaning tank within 40 seconds.
[0024]
To pouring the wafer into the cleaning tank in a short time after polishing the wafer, for example, a finish polishing apparatus and a cleaning apparatus (cleaning tank) may be combined, or a polishing / cleaning system in which the polishing apparatus and the polishing apparatus are adjacent to each other may be employed. . The wafer may be subjected to finish polishing using such a system, and the wafer after polishing may be peeled off from the plate, and may be directly charged into the cleaning tank without being stored in the stock tank.
[0025]
In this case, if the wafer is put into the cleaning tank within 40 seconds after the final polishing, the wafer that has been subjected to the final polishing may be showered before being put into the cleaning tank, or may be omitted. For example, if a shower device is provided between the polishing device and the cleaning device and a shower similar to the conventional one is performed, the abrasive covering the surface of the wafer will be partially removed. Since the particles are put into the cleaning tank in a very short time without being stored, particles hardly adhere.
[0026]
By such a flow, after the wafer is polished, it can be put into the cleaning tank within 40 seconds, during which the particles hardly adhere, and the abrasive on the surface may dry and solidify. Absent. In addition, since the wafer is put into the cleaning tank in a short time after polishing, it is not locally etched by the abrasive remaining on the surface. Next, the wafer cleaned in the cleaning step is free of foreign substances such as abrasives and polishing debris from the whole, and can be made into an extremely clean wafer.
Further, in this aspect, the time from polishing to cleaning is extremely short, so that productivity is also improved.
[0027]
FIG. 2 shows another embodiment of the present invention. Here, the finish-polished semiconductor wafer may be passed through the respective steps of cassette storage, stock tank storage, transport, and cleaning after polishing, as in the related art. The whole is covered with the abrasive and put into the cleaning tank.
[0028]
For example, by performing showering at a low water pressure between each step, the state where the entire surface is covered with the abrasive can be maintained. Specifically, if the pressure is 0.25 MPa or less for a nozzle diameter of 0.1 to 20 mm, water is applied to the wafer at a low pressure. By applying such a low-pressure shower, although the polishing agent covering the wafer surface is entirely removed to some extent, it can be prevented from being partially removed. Therefore, in this embodiment, after the polishing step, the wafer is sent to the cleaning step and charged into the cleaning tank while the surface of the wafer is kept covered with the wet abrasive, during which the abrasive is protected. It acts like a film and can prevent particles from directly adhering to the surface of the wafer.
[0029]
If the low-pressure shower is omitted for the semiconductor wafer that has been polished, the abrasive on the wafer surface may dry and solidify before entering the cleaning step. Therefore, when the low-pressure shower is omitted, the conveying speed may be increased, and the work area may be humidified to prevent the abrasive from drying.
[0030]
FIG. 3 shows still another embodiment in which a shower in which mist of pure water is atomized is provided between the steps of cassette storage, stock tank storage, transport, and cleaning. As for the mist shower, as shown in FIG. 4, the pure water 2 may be ejected from the nozzle of the shower main body 1 in a mist. For example, the shape (injection angle) of the nozzle used for the mist shower may be set to 10 to 180 °, and the particle diameter of water emitted from the outlet may be in the range of 1 μm to 500 μm.
[0031]
When the mist shower is applied in this manner, the abrasive is flowed to some extent from the surface of the wafer, but is not locally removed, and the entire surface of the wafer is maintained in a wet state, and the abrasive is removed. It can be sent to the cleaning process in a state covered with. Therefore, even if 40 seconds have elapsed after the completion of polishing, it is possible to prevent particles from adhering, to prevent the polishing agent from drying and solidifying, and not to cause local etching. Then, in the next cleaning step, an extremely clean wafer can be obtained by removing the abrasive, the polishing residue, and the like.
[0032]
In the present invention, when a shower is performed on the polished wafer, it is preferable to use pure water containing as little particles as possible. For example, fine particles in pure water are also removed using a filter or the like, and pure water (ultra pure water) containing particles having a size of 0.1 μm or more at 100 particles / liter or less is used as shower water. It is desirable to give a mist shower. Small particles of the above level are particularly difficult to remove when they adhere, but in this way, a mist shower using pure water controlled so that the number of fine particles is very small Then, the adhesion of particles before cleaning can be further suppressed.
In addition, not only the mist shower but also a low pressure shower, or even when performing a normal shower while putting it into the cleaning tank within 40 seconds after the final polishing as shown in FIG. It is preferable to use the shower.
[0033]
The low pressure shower and the mist shower as described above are particularly effective when it is difficult to reduce the time after polishing. That is, even if the cassette is stored, the stock tank is stored, and transported as in the conventional case, at least one of a low-pressure shower and a mist-like shower is applied between each process, so that the wafer is polished. Without drying the abrasive covering the surface, and without removing the abrasive by water pressure or the like, the state in which the entire surface is covered with the abrasive can be maintained for a long time. Then, by sending the wafer surface after the final polishing to the first cleaning with the surface of the wafer covered with the polishing agent, the adhesion of particles can be significantly reduced, and uneven etching can be prevented. .
[0034]
When the low pressure shower or the mist shower is performed for a long time, the polishing agent on the wafer surface may be completely removed depending on the length of the time. In such a case, it is possible to reduce the adhesion of particles by immediately (within 40 seconds) putting the cleaning agent into the cleaning tank after the abrasive is removed.
[0035]
【Example】
Hereinafter, examples and comparative examples of the present invention will be described.
(Example 1)
Polishing (finish polishing) of a silicon wafer having a diameter of 200 mm was performed using a single-side polishing apparatus as shown in FIG. In this polishing step, an alkaline solution containing colloidal silica was used as a polishing agent.
After polishing, the wafer was peeled off from the plate, and the wafer was directly put into the cleaning tank without showering. After polishing, the surface of the wafer before cleaning was observed, and the abrasive was uniformly adhered. The surface of the wafer after polishing was sent to the cleaning step in a state covered with the abrasive, and was put into the cleaning tank. Will be. The time from detaching the wafer from the polishing cloth to charging the wafer into the cleaning tank was about 35 seconds.
[0036]
In the cleaning step, cleaning was performed for 20 minutes using SC-1 solution (a mixed solution of ammonia, hydrogen peroxide and water). After the washing, the number of particles having a size of 0.065 μm or more measured as particles on the surface of the wafer with a particle counter was about 25 particles / wafer (no congestion).
[0037]
(Comparative Example 1)
A wafer polished in the same manner as in Example 1 was processed by the conventional method shown in FIG.
Specifically, after polishing, the wafer was peeled off from the plate, the wafer was stored in a cassette, stored in storage water (stock tank) for 30 minutes, and then transported (about 2 minutes) and sent to the cleaning step. . A shower was provided between each of the steps of polishing, cassette storage, stock tank storage, transport, and washing. The showering was performed at a water pressure of 5 MPa for a nozzle diameter of 5 mm, and was performed for about 1 minute between each process. The time from the removal of the wafer from the polishing cloth to the introduction into the cleaning tank was about 40 minutes. In addition, when the wafer surface was observed before cleaning, a portion to which no abrasive was attached was found.
[0038]
In the cleaning step, cleaning was performed in the same manner as in Example 1. After the cleaning, the number of particles having a size of 0.065 μm or more was measured as particles on the surface of the wafer. As a result, it was about 1000 particles / wafer (no congestion).
[0039]
(Example 2)
The wafer polished in the same manner as in Example 1 was processed in the steps shown in FIG.
Specifically, each of the steps of polishing, cassette storage, stock tank storage, transport, and cleaning was performed in the same manner as in the related art, but a mist shower was provided between the respective steps. The mist shower is as shown in FIG. 4. The nozzle used for the mist shower has a shape (injection angle) of about 150 °, and the particle size of pure water ejected from the ejection port ranges from 1 μm to 500 μm. It was a mist.
After cleaning was performed in the same manner as in Example 1, the number of particles having a size of 0.065 μm or more was measured as particles on the surface of the wafer. As a result, it was about 30 particles / wafer (no density).
[0040]
(Example 3)
High-grade water such as ultrapure water was used as the water used for the shower, and a filter having a filtration diameter capable of removing fine particles (near the use point) was provided in the path of the pure water. Thereby, pure water containing particles having a size of 0.1 μm or more at 100 particles / liter or less was obtained.
The sample wafer after the finish polishing was subjected to the same mist shower as in Example 2 using the pure water treated under the above conditions, and the wafer was put into a cleaning step while maintaining a wet state to perform cleaning.
[0041]
After cleaning was performed in the same manner as in Example 1, the number of particles having a size of 0.065 μm or more was measured as particles on the surface of the wafer. As a result, it was about 25 particles / wafer (no congestion). That is, it was found that particles on the wafer surface can be further reduced by the mist shower in which the fine particles in pure water are reduced.
[0042]
The present invention is not limited to the above embodiment. The above-described embodiment is merely an example, and has substantially the same configuration as the technical idea described in the claims of the present invention, and any device having the same function and effect can be provided. It is included in the technical scope of the present invention.
[0043]
For example, after finishing polishing, the time until the wafer is put into the cleaning tank is set to within 40 seconds, and during that time, the polished wafer may be subjected to a mist shower. As a result, the time can be reduced and the particles can be reduced at the same time, which is extremely efficient.
Further, in the above embodiment, the case where the silicon wafer is polished by the single-side polishing apparatus has been described. However, the present invention is not limited to the silicon wafer, and can be applied to other semiconductor wafers. It goes without saying that you can do it.
[0044]
【The invention's effect】
As described above, according to the present invention, it is possible to greatly reduce the adhesion of fine particles after cleaning by omitting each step from polishing of the wafer to cleaning. At the same time, it is possible to manufacture a clean wafer having no part where the surface roughness is deteriorated due to the local etching action. In addition, a mist shower or a low-pressure shower should be applied to prevent partial removal of the abrasive covering the surface of the wafer without omitting each step from the polishing of the wafer to the cleaning. Thus, a clean wafer can be manufactured as described above. As a result, adhesion of particles on the wafer surface and local etching are greatly reduced, thereby improving the yield of the device.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing one example of a method for manufacturing a semiconductor wafer according to the present invention.
FIG. 2 is an explanatory view showing another example of the method for manufacturing a semiconductor wafer according to the present invention.
FIG. 3 is an explanatory view showing still another example of the method for manufacturing a semiconductor wafer according to the present invention.
FIG. 4 is a schematic view showing an example of a mist shower according to the present invention.
FIG. 5 is an explanatory view showing a conventional method for manufacturing a semiconductor wafer.
FIG. 6 is a schematic view showing an example of a conventional shower.
FIG. 7 is a schematic view showing an example of a single-side polishing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Shower body, 2 ... Pure water, 11 ... Shower body, 12 ... Pure water, 30 ... Surface plate, 31 ... Single-side polishing apparatus, 32 ... Polishing cloth, 33 ... Polishing plate, 34 ... Polishing liquid supply nozzle, 39 ... Abrasive.

Claims (5)

At least, a polishing agent is supplied to the polishing cloth while rotating the polishing cloth attached to the surface plate, and a final polishing step of performing final polishing by sliding a semiconductor wafer on the polishing cloth; A semiconductor wafer manufacturing method having a cleaning step of performing cleaning by charging the semiconductor wafer into a cleaning tank, wherein the semiconductor wafer is finished and polished, and then charged into the cleaning tank within 40 seconds. Wafer manufacturing method. At least, a polishing agent is supplied to the polishing cloth while rotating the polishing cloth attached to the surface plate, and a final polishing step of performing final polishing by sliding a semiconductor wafer on the polishing cloth; A semiconductor wafer manufacturing method having a cleaning step of performing the cleaning by charging the semiconductor wafer into the cleaning tank, wherein the finish-polished semiconductor wafer is charged into the cleaning tank in a state where the surface is covered with the abrasive. A method for manufacturing a semiconductor wafer, comprising: The method according to claim 1, wherein after the semiconductor wafer is finish-polished, the semiconductor wafer is directly charged into the cleaning tank. After the finish polishing step and before the cleaning step, the finish-polished semiconductor wafer is subjected to a shower in which water is atomized and the water pressure is set to 0.25 MPa or less for a nozzle diameter of 0.1 to 20 mm. 3. The method for producing a semiconductor wafer according to claim 1, wherein at least one type of shower is applied. The method for producing a semiconductor wafer according to claim 4, wherein pure water containing particles having a size of 0.1 µm or more at 100 particles / liter or less is used as the water for showering.

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