JP7480594B2 - Electronic component cleaning water manufacturing equipment - Google Patents

Description

The present invention relates to an apparatus for producing cleaning water for electronic components and electronic materials used in the electronics industry and the like, and in particular to an apparatus for producing cleaning water for electronic components and electronic materials that can control the cleaning properties of the cleaning water for electronic components and electronic materials by adjusting the conductivity and redox potential by adding ammonia or aqueous peroxide.

Solutions in which electrical conductivity-imparting substances, substances that control redox potential, and gases have been added to ultrapure water are used as cleaning water for processing electronic parts and materials such as semiconductor wafers and semiconductor devices. In addition, ultrapure water is used in the rinsing process after cleaning with these methods. However, the higher the purity of ultrapure water, the higher its resistivity becomes, which is known to cause problems such as electrostatic damage to insulating films and re-adhesion of fine particles. For this reason, dilute chemical solutions in which carbon dioxide gas or ammonia is dissolved in ultrapure water are used as rinsing water to adjust the pH and reduce static electricity, addressing the above-mentioned problems.

In recent years, however, there has been an increasing need to clean wafers without dissolving certain substances on the wafer surface. To achieve this, specific cleaning solutions are prepared according to the wafer material, and cleaning is carried out using these cleaning solutions.

However, preparing cleaning solutions according to the wafer material is expensive, and it is difficult to collect wastewater containing the cleaning solutions and reuse the cleaning solutions, which is problematic in that it also requires high chemical costs.

Therefore, it is considered to use a mixture of ammonia water, hydrogen peroxide water, and water, which has been used in the RCA cleaning, which is a wet cleaning method for semiconductor substrates, as the cleaning liquid. For example, as shown in FIG. 2, a cleaning liquid manufacturing device 11 includes an ammonia water supply device 13 as a conductivity imparting agent connected to a supply line 12 of ultrapure water W via a pipe 13A equipped with an on-off valve 13B, and a hydrogen peroxide water supply device 14 as an oxidation-reduction potential regulator connected via a pipe 14A equipped with an on-off valve 14B, and the end of the ultrapure water supply line 12 is a use point UP. A conductivity meter 15 is provided downstream of the ammonia water supply device 13 on the ultrapure water supply line 12, and an ORP meter 6 is provided downstream of the hydrogen peroxide water supply device 14, and based on the measured values, the amount of ammonia water supplied from the ammonia water supply device 13 and the amount of hydrogen peroxide water supplied from the hydrogen peroxide water supply device 14 can be controlled.

In this type of cleaning liquid manufacturing device 11, ammonia water is added to ultrapure water W to make the pH alkaline and increase the conductivity, and hydrogen peroxide water is added to increase the redox potential in the positive direction, and the wafer is cleaned with this alkaline cleaning liquid, which etches and removes the wafer surface through a chemical reaction. This basic mechanism poses the problem that it is difficult to control the solubility so that only the specified material on the wafer surface dissolves. One possible solution to this problem is to adjust the chemical solution to a dilute form, but there is a limit to how dilute the chemical solution can be adjusted, and as it is, it is still difficult to control the solubility so that only the specified material on the wafer surface dissolves.

The present invention has been made in consideration of the above problems, and aims to provide an apparatus for producing cleaning water for electronic components and electronic materials that can adjust the electrical conductivity and redox potential and control the cleaning properties of electronic components and electronic materials.

In view of the above object, the present invention provides an electronic component cleaning water manufacturing device that adds a conductivity imparting agent and an oxidation-reduction potential adjuster to ultrapure water to produce electronic component cleaning water with a desired conductivity and oxidation-reduction potential, and supplies the electronic component cleaning water to a use point, the electronic component cleaning water manufacturing device being provided with a conductivity imparting agent injection device and an oxidation-reduction potential adjuster injection device in the ultrapure water supply line, and a cooling mechanism being provided between the conductivity and oxidation-reduction potential adjustment means and the use point (Invention 1).

According to this invention (Invention 1), electronic component cleaning water is prepared by adding trace amounts of a conductivity imparting agent and an oxidation-reduction potential adjuster to ultrapure water, and this electronic component cleaning water is cooled to a predetermined temperature by a cooling mechanism and supplied to the point of use, thereby reducing the activity of the electronic component cleaning water and suppressing the dissolution of electronic components such as wafers. Furthermore, by making it into a dilute solution to which trace amounts of a conductivity imparting agent and an oxidation-reduction potential adjuster have been added, it is possible to control the solubility so that only the specified material on the surface of electronic components such as wafers is dissolved.

In the above invention (Invention 1), it is preferable that the conductivity imparting agent is ammonia or carbonic acid (Invention 2).

According to this invention (Invention 2), it is possible to impart conductivity to the electronic component cleaning water while adjusting the liquid property to alkaline or acidic, and furthermore, by adjusting the concentration, it is possible to adjust the pH of the electronic component cleaning water.

In the above inventions (Inventions 1 and 2), it is preferable that the oxidation-reduction potential regulator is hydrogen peroxide, _O3 or _H2 (Invention 3).

According to such inventions (Inventions 2 and 3), the redox potential of the cleaning water for electronic components can be adjusted to be positive or negative, and the redox potential of the cleaning water for electronic components can be adjusted by adjusting the concentration.

In the above inventions (Inventions 1 to 3), it is preferable that the cooling mechanism is capable of supplying electronic component cleaning water to the point of use at 20°C or less (Invention 4).

According to this invention (Invention 4), by adding trace amounts of a conductivity imparting agent and an oxidation-reduction potential adjuster to ultrapure water and cooling it to 20°C or less to wash electronic components, the dissolution of electronic components such as wafers can be effectively suppressed by supplying the cleaning water to the point of use.

In the above inventions (Inventions 1 to 4), it is preferable that the ultrapure water supply line is provided with a conductivity meter or resistivity meter downstream of the conductivity imparting agent injection device, and that an oxidation-reduction agent concentration measuring device or ORP meter is provided downstream of the oxidation-reduction potential regulator injection device (Invention 5).

According to this invention (Invention 5), the conductivity and ORP of electronic component cleaning water, which is ultrapure water to which a trace amount of a conductivity imparting agent and an oxidation-reduction potential adjuster have been added, are measured, and the amounts added from the conductivity imparting agent injection device and the oxidation-reduction potential adjuster injection device are controlled according to the measured values, thereby adjusting the conductivity and oxidation-reduction potential of the electronic component cleaning water and making it possible to more effectively suppress dissolution of electronic component materials such as wafers.

According to the electronic component cleaning water manufacturing device of the present invention, electronic component cleaning water, which is ultrapure water to which trace amounts of a conductivity imparting agent and an oxidation-reduction potential adjuster have been added, is cooled to a predetermined temperature by a cooling mechanism and supplied to the point of use, making it possible to clean electronic components such as wafers while suppressing dissolution. Furthermore, by making it a dilute solution to which trace amounts of a conductivity imparting agent and an oxidation-reduction potential adjuster have been added, it is possible to control the solubility so that only the specified material on the surface of electronic components such as wafers is dissolved.

1 is a schematic diagram showing an apparatus for producing electronic component cleaning water according to an embodiment of the present invention. FIG. 1 is a schematic diagram showing a conventional apparatus for producing cleaning water for electronic components.

The first embodiment of the electronic component cleaning water manufacturing device of the present invention will be described in detail below with reference to the attached drawings.

[Apparatus for producing cleaning water for electronic components]
1 shows an apparatus for producing cleaning water for electronic components (hereinafter, sometimes simply referred to as cleaning water) according to one embodiment, and in FIG. 1, the apparatus for producing cleaning water for electronic components 1 includes a conductivity imparting agent supplying device 3 connected to a supply line 2 for ultrapure water W via a pipe 3A equipped with an on-off valve 3B, and an oxidation-reduction potential adjuster supplying device 4 connected via a pipe 4A equipped with an on-off valve 4B. The end of the ultrapure water supply line 2 is a use point UP, and a cooling mechanism 7 is provided in front of the use point UP. In this embodiment, a conductivity meter 5 is provided in the downstream of the conductivity imparting agent supplying device 3 on the ultrapure water supply line 2, and an ORP meter 6 is provided in the downstream of the oxidation-reduction potential adjuster supplying device 4, and based on the measured values thereof, the supply amount of the conductivity imparting agent from the conductivity imparting agent supplying device 3 and the supply amount of the oxidation-reduction potential adjuster from the oxidation-reduction potential adjuster supplying device 4 can be controlled by a control mechanism (not shown).

The cooling mechanism 7 is called a chiller, and in this embodiment, it is preferable that the chiller has the capacity to supply cleaning water W1 for electronic components at a temperature of 20°C or less, for example 10 to 20°C, to the point of use UP relative to the flow rate of ultrapure water W at room temperature.

<Ultrapure water>
In this embodiment, the ultrapure water W serving as the raw water preferably has, for example, a resistivity of 18.1 MΩ cm or more, fine particles: 1000 particles/L or less with a particle size of 50 nm or more, live bacteria: 1 particle/L or less, TOC (Total Organic Carbon): 1 μg/L or less, total silicon: 0.1 μg/L or less, metals: 1 ng/L or less, ions: 10 ng/L or less, hydrogen peroxide: 30 μg/L or less, and a water temperature of 25±2° C.

<Conductive agent>
In this embodiment, the conductivity imparting agent means a substance that dissolves in ultrapure water W, which is raw water, to generate ions (anions or cations) and imparts conductivity to the ultrapure water W by the ions. As such a conductivity imparting agent, liquids such as hydrochloric acid, nitric acid, sulfuric acid, and acetic acid, and gases such as CO ₂ gas can be used as acidic imparting agents. In addition, as an alkaline imparting agent, ammonia, sodium hydroxide, potassium hydroxide, TMAH, etc. can be used, but when used to clean semiconductor wafers, ammonia and CO ₂ (which may be dissolved in water) are suitable, and ammonia is particularly suitable. This ammonia is preferably used as ammonia water of a predetermined concentration. These conductivity imparting agents may be appropriately selected according to the desired liquid properties, such as the pH of the cleaning liquid.

<Oxidation-reduction potential regulator>
In this embodiment, the redox potential adjuster means a substance that dissolves in ultrapure water W, which is raw water, to impart oxidizing or reducing properties and change the redox potential. There is no particular limitation on such redox potential adjusters, but potassium ferricyanide and potassium ferrocyanide are not preferred because they contain metal components. Therefore, when adjusting the redox potential to a higher level, liquids such as hydrogen peroxide water, gases such as ozone gas and oxygen gas can be used. When adjusting the redox potential to a lower level, liquids such as oxalic acid, hydrogen sulfide, potassium iodide, and gases such as hydrogen are preferably used. When used to clean semiconductor wafers, liquids such as hydrogen peroxide water, gases such as ozone gas and hydrogen gas (which may be dissolved water), and hydrogen peroxide water are particularly preferred because the control of the redox potential is relatively easy. These redox potential adjusters may be selected according to the desired liquid properties, such as the positive or negative redox potential of the cleaning liquid.

[Method for producing electronic component cleaning water]
Next, a method for producing cleaning water for electronic components using the apparatus for producing cleaning water for electronic components according to this embodiment having the above-mentioned configuration will be described.

<Conductivity imparting step>
First, when ultrapure water W is supplied from the supply line 2, a necessary amount of the conductivity imparting agent is added from the conductivity imparting agent supply device 3 based on the concentration of the conductivity imparting agent that results in a set conductivity from the flow rate of this ultrapure water W. At this time, it is preferable to measure the conductivity of the ultrapure water W after the addition of the conductivity imparting agent by a conductivity meter 5 provided on the supply line 2, and adjust the amount of the conductivity imparting agent to be added so as to achieve the set conductivity.

It is preferable to set the conductivity of the ultrapure water W to 5 μS/cm or less by the above-mentioned conductivity imparting process. If the conductivity of the ultrapure water W exceeds 5 μS/cm, the effect of suppressing cleaning of the wafer surface is insufficient. Therefore, it is sufficient to add only a very small amount of the conductivity imparting agent.

<Oxidation-reduction potential adjustment step>
Next, a necessary amount of the oxidation-reduction potential adjuster is added from the oxidation-reduction potential adjuster supply device 4 based on the concentration of the oxidation-reduction potential adjuster that will result in the oxidation-reduction potential set from the flow rate of the ultrapure water W. At this time, it is preferable to measure the oxidation-reduction potential of the ultrapure water W after the addition of the oxidation-reduction potential adjuster with an ORP meter 6 provided in the supply line 2, and adjust the amount of the oxidation-reduction potential adjuster to be added so as to achieve the set oxidation-reduction potential.

In the above-mentioned oxidation-reduction potential adjusting step, if the oxidation-reduction potential of the ultrapure water W is made too large, the effect of inhibiting cleaning of the wafer surface is insufficient, and therefore it is preferable to dissolve the oxidation-reduction potential adjuster in an extremely dilute state so that the oxidation-reduction potential is less than about ±10 V. In this embodiment in which the raw water is ultrapure water W, specifically, when the oxidation-reduction potential adjuster is hydrogen peroxide, the concentration is preferably 50 ppm or less, particularly 10 ppm or less, when the oxidation-reduction potential adjuster is ozone (O ₃ ), the concentration is preferably 10 ppm or less, particularly 5 ppm or less, and when the oxidation-reduction potential adjuster is hydrogen (H ₃ ), the concentration is preferably 1 ppm or less, particularly 0.5 ppm or less.

<Cooling process>
The cleaning water W1, which is obtained by adjusting the ultrapure water W to the desired conductivity and oxidation-reduction potential in this manner, is highly active, and it is difficult to control the solubility, such as selectively dissolving only a specific material on the wafer surface. Therefore, it is preferable that the cleaning water W1 is supplied to the point of use UP at 20° C. or less. Therefore, it is preferable to cool the cleaning water W1 to a temperature between 0° C. and less than 20° C. by the cooling mechanism 7. For this reason, it is preferable to measure the temperature of the cleaning water W1 at the outlet of the cooling mechanism 7 and adjust it to the desired temperature by controlling the cooling capacity of the cooling mechanism 7.

The cooling process may be performed by using a chiller unit having multiple chillers connected in parallel as the cooling mechanism 7 and switching the operating state of the multiple chillers depending on the degree of deterioration of the cooling function of each chiller. By switching the operating state of the multiple chillers, the chiller to be used can be selected. Therefore, even if there is a chiller whose cooling function has deteriorated due to the generation of microorganisms, for example, the operation of the entire chiller unit can be continued without being stopped, and the production efficiency of the cooled cleaning water W1 is improved.

As described above, according to the electronic component cleaning water manufacturing device of this embodiment, the activity of the cleaning water W1 for the wafer is reduced by using low-temperature cleaning water W1 cooled to a predetermined temperature, particularly a temperature of 0°C or higher but lower than 20°C, and the solubility of the cleaning water 1 can be controlled, such as by dissolving only the specified material on the wafer surface. In particular, according to this embodiment, the solubility of the cleaning water 1 is controlled by using a low concentration of a conductivity imparting agent and an oxidation-reduction potential adjuster, such that only the specified material on the wafer surface is dissolved, and therefore the amount of chemical solution used can be reduced. This also has the effect of making it easier to recover and reuse the used solution.

The present invention has been described above based on the above embodiment with reference to the attached drawings, but the present invention is not limited to the above embodiment and various modifications are possible. For example, it is common to use ammonia as the conductivity imparting agent and hydrogen peroxide as the redox potential adjuster, but various combinations of conductivity imparting agents and redox potential adjusters are possible. In addition, ultrapure water W may be cooled and used as a cleaning liquid without adding the conductivity imparting agent and the redox potential adjuster from the conductivity imparting agent supply device 3 and the redox potential adjuster supply device 4.

The present invention will be explained in more detail with the following specific examples.

[Comparative Example 1]
Using the cleaning liquid production device shown in FIG. 1 without the cooling mechanism 7, ammonia water (conductivity imparting agent) was added from the conductivity imparting agent supplying device 3 to ultrapure water W at room temperature so that the conductivity was 100 μS/cm, and then hydrogen peroxide water (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 to 100 ppm to produce cleaning water W1. Then, this cleaning water W1 was sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 25° C. At this time, a large amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) was required, and the concentrations of ammonia and hydrogen peroxide were high, making it difficult to recover and reuse the cleaning liquid 1. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1.

[Comparative Example 2]
In Comparative Example 1, cleaning water W1 was produced in the same manner, except that ammonia (conductivity imparting agent) water was added from the conductivity imparting agent supplying device 3 to the ultrapure water W at room temperature so that the conductivity was 1 μS/cm. Then, this cleaning water W1 was sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 25° C. At this time, a large amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) was required, and recovery and reuse of the cleaning liquid 1 was difficult. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. In addition, the wafer dissolution suppression effect when the wafer dissolution suppression effect of the cleaning liquid W1 of Comparative Example 1 is set to 100% (the higher the suppression effect, the greater the effect), the amount of cleaning liquid W1 used compared to Comparative Example 1, and the judgment of whether recovery and reuse of the cleaning liquid 1 is difficult or easy are also shown in Table 2.

[Comparative Example 3]
In Comparative Example 1, ammonia (conductivity imparting agent) water was added from the conductivity imparting agent supplying device 3 to ultrapure water W at room temperature so that the conductivity was 100 μS/cm, and then ozone (O ₃ ) (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 so that the concentration was 30 ppm to produce cleaning water W1. Then, this cleaning water W1 was sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 25° C. At this time, a large amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) was required, and recovery and reuse of the cleaning liquid 1 was difficult. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. In addition, the wafer dissolution suppression effect when the wafer dissolution suppression effect of the cleaning liquid W1 of Comparative Example 1 is set to 100%, the amount of cleaning liquid W1 used compared to Comparative Example 1, and the judgment of whether recovery and reuse of the cleaning liquid 1 is difficult or easy are also shown in Table 2.

[Comparative Example 4]
In Comparative Example 1, ammonia (conductivity imparting agent) water was added from the conductivity imparting agent supplying device 3 to the ultrapure water W at room temperature so that the conductivity was 100 μS/cm, and then hydrogen (H ₂ ) (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 so that the concentration was 1.2 ppm to produce cleaning water W1. Then, this cleaning water W1 was sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 25° C. At this time, a large amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) was required, and recovery and reuse of the cleaning liquid 1 was difficult. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. In addition, the wafer dissolution suppression effect when the wafer dissolution suppression effect of the cleaning liquid W1 of Comparative Example 1 is set to 100%, the amount of cleaning liquid W1 used compared to Comparative Example 1, and the judgment of whether recovery and reuse of the cleaning liquid 1 is difficult or easy are also shown in Table 2.

[Comparative Example 5]
In Comparative Example 1, CO ₂ (conductivity imparting agent) was added from the conductivity imparting agent supplying device 3 to the ultrapure water W at room temperature so that the conductivity was 10 μS/cm, and then hydrogen peroxide water (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 to 100 ppm to produce cleaning water W1. Then, this cleaning water W1 was sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 25° C. At this time, a large amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) was required, and recovery and reuse of the cleaning liquid 1 was difficult. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. In addition, the wafer dissolution suppression effect when the wafer dissolution suppression effect of the cleaning liquid W1 of Comparative Example 1 is set to 100%, the amount of cleaning liquid W1 used compared to Comparative Example 1, and the judgment of whether recovery and reuse of the cleaning liquid 1 is difficult or easy are also shown in Table 2.

[Example 1]
Using the cleaning liquid manufacturing apparatus shown in FIG. 1, ammonia water (conductivity imparting agent) was added from the conductivity imparting agent supplying device 3 to ultrapure water W at room temperature so that the conductivity was 1 μS/cm, and then hydrogen peroxide (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 to 5 ppm to produce cleaning water W1. Then, this cleaning water W1 was cooled by the cooling mechanism 7 and sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 15° C. At this time, the amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) used was small compared to Comparative Example 1, and the concentrations of ammonia water and hydrogen peroxide water were low, so that recovery and reuse of the cleaning liquid 1 was relatively easy. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. Table 2 also shows the wafer dissolution suppression effect when the wafer dissolution suppression effect of cleaning solution W1 in Comparative Example 1 is taken as 100%, the amount of cleaning solution W1 used compared to Comparative Example 1, and a judgment of whether it is difficult or easy to recover and reuse cleaning solution W1.

[Example 2]
In Example 1, ammonia (conductivity imparting agent) water was added from the conductivity imparting agent supplying device 3 to the ultrapure water W at room temperature so that the conductivity was 1 μS/cm, and then ozone (O ₃ ) (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 so that the concentration was 2 ppm to produce cleaning water W1. Then, this cleaning water W1 was cooled by the cooling mechanism 7 and sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 15° C. At this time, the amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) used was small compared to Comparative Example 1, and recovery and reuse of the cleaning liquid 1 was relatively easy. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. In addition, the wafer dissolution suppression effect when the wafer dissolution suppression effect of the cleaning liquid W1 of Comparative Example 1 is set to 100%, the amount of cleaning liquid W1 used compared to Comparative Example 1, and the judgment of whether recovery and reuse of the cleaning liquid 1 is difficult or easy are also shown in Table 2.

[Example 3]
In Example 1, ammonia (conductivity imparting agent) water was added from the conductivity imparting agent supplying device 3 to the ultrapure water W at room temperature so that the conductivity was 1 μS/cm, and then hydrogen (H ₂ ) (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 so that the concentration was 0.2 ppm to produce cleaning water W1. Then, this cleaning water W1 was cooled by the cooling mechanism 7 and sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 15° C. At this time, the amount of chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) used was small compared to Comparative Example 1, and recovery and reuse of the cleaning liquid 1 was relatively easy. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. In addition, the wafer dissolution suppression effect when the wafer dissolution suppression effect of the cleaning liquid W1 of Comparative Example 1 is set to 100%, the amount of cleaning liquid W1 used compared to Comparative Example 1, and the judgment of whether recovery and reuse of the cleaning liquid 1 is difficult or easy are also shown in Table 2.

[Example 4]
In Example 1, CO ₂ (conductivity imparting agent) was added from the conductivity imparting agent supplying device 3 to the ultrapure water W at room temperature so that the conductivity was 1 μS/cm, and then hydrogen peroxide (oxidation-reduction potential adjuster) was added from the oxidation-reduction potential adjuster supplying device 4 to 5 ppm to produce cleaning water W1. Then, this cleaning water W1 was cooled by the cooling mechanism 7 and sent to the use point to clean the wafer. The liquid temperature of the cleaning water W1 at the use point was 15° C. At this time, the amount of the chemical solution (conductivity imparting agent + oxidation-reduction potential adjuster) used was small compared to Comparative Example 1, and the recovery and reuse of the cleaning liquid 1 was relatively easy. The adjustment conditions of this cleaning water W1 and the liquid temperature at the use point UP are shown in Table 1. In addition, the wafer dissolution suppression effect when the wafer dissolution suppression effect of the cleaning liquid W1 of Comparative Example 1 is set to 100%, the amount of the cleaning liquid W1 used compared to Comparative Example 1, and the judgment of whether the recovery and reuse of the cleaning liquid 1 is difficult or easy are also shown in Table 2.

[Reference Example 1]
In Comparative Example 1, no conductivity imparting agent or oxidation-reduction potential adjuster was added to ultrapure water W at room temperature, and the water was sent as it was to the point of use as cleaning water W1 to clean the wafer. The liquid temperature of cleaning water W1 at the point of use was 25° C. The preparation conditions of cleaning water W1 and the liquid temperature at the point of use UP are shown in Table 1. Table 2 also shows the wafer dissolution suppression effect when the wafer dissolution suppression effect of cleaning liquid W1 in Comparative Example 1 is taken as 100%, the wafer dissolution suppression effect, the amount of cleaning liquid W1 used compared to Comparative Example 1, and a judgment of whether recovery and reuse of cleaning liquid 1 is difficult or easy.

[Reference Example 2]
In Example 1, ultrapure water W at room temperature was used as cleaning water W1 as it was, and this cleaning water W1 was cooled by cooling mechanism 7 and sent to the point of use to clean the wafer. The liquid temperature of cleaning water W1 at the point of use was 20° C. The preparation conditions of this cleaning water W1 and the liquid temperature at the point of use UP are shown in Table 1. Table 2 also shows the wafer dissolution suppression effect when the wafer dissolution suppression effect of cleaning liquid W1 in Comparative Example 1 is taken as 100%, the amount of cleaning liquid W1 used compared to Comparative Example 1, and a judgment of whether recovery and reuse of cleaning liquid 1 is difficult or easy.

[Reference Example 3]
In Example 1, ultrapure water W at room temperature was used as cleaning water W1 as it was, and this cleaning water W1 was cooled by cooling mechanism 7 and sent to the point of use to clean the wafer. The liquid temperature of cleaning water W1 at the point of use was 15° C. The preparation conditions of this cleaning water W1 and the liquid temperature at the point of use UP are shown in Table 1. Table 2 also shows the wafer dissolution suppression effect when the wafer dissolution suppression effect of cleaning liquid W1 in Comparative Example 1 is taken as 100% (the higher the suppression effect, the greater the effect), the amount of cleaning liquid W1 used compared to Comparative Example 1, and a judgment of whether recovery and reuse of cleaning liquid 1 is difficult or easy.

[Reference Example 4]
In Example 1, ultrapure water W at room temperature was used as cleaning water W1 as it was, and this cleaning water W1 was cooled by cooling mechanism 7 and sent to the point of use to clean the wafer. The liquid temperature of cleaning water W1 at the point of use was 10° C. The preparation conditions of this cleaning water W1 and the liquid temperature at the point of use UP are shown in Table 1. Table 2 also shows the wafer dissolution suppression effect when the wafer dissolution suppression effect of cleaning liquid W1 in Comparative Example 1 is taken as 100%, the amount of cleaning liquid W1 used compared to Comparative Example 1, and a judgment of whether recovery and reuse of cleaning liquid 1 is difficult or easy.

As is clear from Tables 1 and 2, the cleaning water W1 of Examples 1 to 4 cooled to 15°C had a higher effect of inhibiting the dissolution of the wafer than when the wafer was cleaned with cleaning water W1 at 25°C, and because the amount of chemical used was small and the solution was dilute, recovery was relatively easy. Also, as is clear from Reference Examples 1 to 4, even when ultrapure water W, which is the raw water, was used as the cleaning water, Reference Example 1 at 25°C had a low effect of inhibiting the dissolution of the wafer, whereas the lower the temperature, the higher the effect of inhibiting the dissolution of the wafer. This shows that the effect of inhibiting the dissolution of the wafer can be adjusted by adjusting the temperature of the cleaning water W1.

1 Electronic component cleaning water production device 2 Supply line 3 Conductivity imparting agent supply device 3A Pipe 3B Opening/closing valve 4 Oxidation-reduction potential adjuster supply device 4A Pipe 4B Opening/closing valve 5 Conductivity meter 6 ORP meter 7 Cooling mechanism W Ultrapure water W1 Cleaning water UP Use point

Claims (4)

An apparatus for producing cleaning water for electronic components, the apparatus producing cleaning water for electronic components having desired electrical conductivity and oxidation-reduction potential by adding an electrical conductivity imparting agent and an oxidation-reduction potential adjuster to ultrapure water, and supplying the cleaning water for electronic components to a point of use, comprising:
The ultrapure water supply line is provided with a conductivity imparting agent injection device and an oxidation-reduction potential adjusting agent injection device,
a cooling mechanism is provided between the electrical conductivity and oxidation-reduction potential adjusting means and a point of use;
The apparatus for producing electronic component washing water , wherein the conductivity imparting agent is ammonia . The apparatus for producing electronic component cleaning water according to claim 1 , wherein the oxidation-reduction potential adjuster is hydrogen peroxide, _O3 or _H2 . 3. The apparatus for producing cleaning water for electronic components according to claim 1, wherein the cooling mechanism is capable of supplying the cleaning water for electronic components to a point of use at a temperature of 20° C. or lower. 4. The apparatus for producing electronic component cleaning water according to claim 1, further comprising a conductivity meter or a resistivity meter provided downstream of the device for injecting a conductivity imparting agent in the ultrapure water supply line, and a device for measuring an oxidation-reduction agent concentration or an ORP meter provided downstream of the device for injecting an oxidation-reduction potential adjuster.

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