JP2025077683A - pH/oxidation-reduction potential adjusted water manufacturing device, pH/oxidation-reduction potential adjusted water manufacturing method, and semiconductor device manufacturing method - Google Patents

Abstract

To provide a pH/oxidation-reduction potential adjusted water manufacturing device capable of dissolving a predetermined amount of wiring metal.SOLUTION: There is provided a pH/oxidation-reduction potential adjusted water manufacturing device 1 including: a hydrogen peroxide removing mechanism 3 for removing hydrogen peroxide dissolved in pure water W from the pure water, a first branch line 4, a second branch line 5, and a merging line 6, in which the first branch line 4 includes a first pH adjusting device 41A, an oxidation-reduction potential adjusting device 42A, and a first storage tank 43, which are arranged in this order, and the second branch line 5 includes a second pH adjusting device 51A and a second storage tank 53 arranged in this order, and the merging line 6 is configured to alternately circulate first adjusted water W1, pH of which has been adjusted to be within a range of 9 to 14 and an oxidation-reduction potential of which has been adjusted to be within a range of 0.1 to 1.0 V (vs Ag/AgCl) by the first branch line 4, and second adjusted water W2, pH of which has been adjusted to be within a range of 0 to 5 by the second branch line 5.SELECTED DRAWING: Figure 1

Description

The present invention relates to an apparatus for producing pH/oxidation-reduction potential adjusted water, a method for producing pH/oxidation-reduction potential adjusted water, and a method for producing a semiconductor device.

In recent years, semiconductor miniaturization has reached its limits, but the need for more sophisticated semiconductors continues to grow. As a result, three-dimensional integration technology, which stacks semiconductors vertically to improve integration per unit area, is considered an essential technology for next-generation semiconductor manufacturing as an alternative to conventional miniaturization techniques for increasing the integration density of semiconductors.

Generally, the wafer-to-wafer (W2W) process involves the following steps: planarizing the wafer surface, activating the wafer surface with plasma, cleaning the wafer surface and making it hydrophilic by wafer cleaning, bonding the wafers together, and improving the bonding strength by heat treatment.

This process is also the same in hybrid bonding technology, which simultaneously bonds dissimilar materials, an insulating film and a transition metal (copper) that serves as the wiring metal. In the W2W process, the roughness of the wafer surface affects the wafer bonding strength, so it is necessary to control the amount of dissolved wiring metal exposed on the wafer surface to prevent wafer bonding failure.

The insulating film exposed on the wafer surface is harder than the transition metal (copper) that is the wiring metal, which causes differences in the polishing speed and is prone to a phenomenon called dishing, in which the center of the wiring metal is recessed. For this reason, it is very difficult to completely flatten the wafer surface in the wafer surface flattening process before bonding. Therefore, there is a need for technology that can strictly control the amount of wiring metal dissolved into the insulating film, preventing poor bonding of the insulating film and/or wiring metal.

One such technology being investigated involves melting a specified amount of wiring metal after planarizing the wafer surface, and then activating the wafer surface, bonding, and performing heat treatment to cause the wiring metal to thermally expand, thereby preventing wafer bonding defects caused by failure to bond the insulating film and wiring metal.

One known method of extremely fine etching that dissolves a specified amount of metal wiring, such as copper wiring, is called digital etching, which involves alternating treatment with two liquids, diluted hydrogen peroxide and diluted hydrofluoric acid, to repeatedly oxidize and dissolve the surface of the copper wiring, gradually removing the copper wiring.

However, with conventional ultra-fine etching techniques such as digital etching, there are problems with pattern loading, where the amount of dissolved metal varies depending on the width of the wiring, and with the amount of dissolved metal being uneven across the wafer surface. Even if ultra-fine etching is possible, this can lead to poor wafer bonding and adverse effects on semiconductor performance.

In addition, deterioration of the surface roughness of the wiring metal surface after micro-etching can lead to poor wafer bonding, so it is necessary to prevent the surface roughness from worsening before and after micro-etching.

However, conventional etching solutions do not allow precise control of copper dissolution, which can lead to poor wafer bonding due to failure to bond the insulating film and wiring metal.

International Publication No. 2022/034712 International Publication No. 2018/179493

The present invention has been made in consideration of the above circumstances, and aims to provide an apparatus for producing pH/oxidation-reduction potential adjusted water capable of dissolving a predetermined amount of wiring metal in a semiconductor wiring manufacturing process that uses copper as the wiring metal, a method for producing pH/oxidation-reduction potential adjusted water, and a method for producing semiconductor device.

In order to solve the above problems, the present invention employs the following configuration.
[1] A hydrogen peroxide removal mechanism that removes hydrogen peroxide dissolved in pure water from the pure water;
a first branch line and a second branch line branched off at a downstream side of the hydrogen peroxide removal mechanism;
a junction line formed by junction of the first branch line and the second branch line,
a first pH adjusting device for adjusting a pH of the pure water, an oxidation-reduction potential adjusting device for adjusting an oxidation-reduction potential of the pure water, and a first storage tank are arranged in this order in the first branch line;
a second pH adjusting device for adjusting a pH of the pure water and a second storage tank are arranged in this order in the second branch line;
The confluence line is configured to alternately circulate first adjusted water, the pH of which has been adjusted to a range of 9 to 14 and the redox potential of which has been adjusted to a range of 0.1 to 1.0 V (vs Ag/AgCl) by the first branch line, and second adjusted water, the pH of which has been adjusted to a range of 0 to 5 by the second branch line.
[2] The apparatus for producing pH/oxidation-reduction potential adjusted water described in [1], wherein the first pH adjustment device adds at least one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, and tetrahydroammonium to the pure water.
[3] The second pH adjustment device adds at least one selected from the group consisting of hydrochloric acid, hydrofluoric acid, citric acid, acetic acid, formic acid and carbon dioxide to the pure water. This is the apparatus for producing pH/oxidation-reduction potential adjusted water described in [1].
[4] The apparatus for producing pH/oxidation-reduction potential adjusted water described in [1], wherein the oxidation-reduction potential adjusting device adds at least one selected from the group consisting of hydrogen peroxide, ozone, and oxygen to the pure water.
[5] The apparatus for producing pH/oxidation-reduction potential adjusted water described in [1], wherein a first degassing membrane device and a first gas dissolving membrane device for dissolving an inert gas are provided between the oxidation-reduction potential adjustment device and the first storage tank.
[6] The apparatus for producing pH/oxidation-reduction potential adjusted water described in [1], wherein a second degassing membrane device and a second gas dissolution membrane device for dissolving an inert gas are provided between the second pH adjustment device and the second storage tank.
[7] The apparatus for producing pH/oxidation-reduction potential adjusted water according to claim 1, wherein the first adjusted water and the second adjusted water each have a hydrogen peroxide content of 1000 ppm or less.
[8] The apparatus for producing pH/oxidation-reduction potential adjusted water described in [1], wherein the junction line is connected to a substrate processing apparatus that processes the surface of a semiconductor substrate having a wiring layer and an insulating layer made of copper or a copper alloy formed on the surface of the semiconductor substrate before the semiconductor substrate is bonded to another semiconductor substrate.
[9] a hydrogen peroxide removal step of removing hydrogen peroxide dissolved in the pure water from the pure water;
a first adjusted water producing step of producing a first adjusted water having a pH adjusted to 9 to 14 and an oxidation-reduction potential adjusted to +0.1 to +1.0 V (vs. Ag/AgCl) by performing a first pH adjustment and an oxidation-reduction potential adjustment on the pure water after the hydrogen peroxide removal step;
a second adjusted water producing step of producing a second adjusted water having a pH adjusted to a range of 0 to 5 by performing a second pH adjustment on the pure water after the hydrogen peroxide removing step;
a supplying step of alternately supplying the first adjusted water and the second adjusted water to a semiconductor manufacturing process through one supply line.
[10] The method for producing pH/oxidation-reduction potential adjusted water described in [9], wherein the first pH adjustment is performed by adding at least one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, and tetrahydroammonium to the pure water.
[11] The method for producing pH/oxidation-reduction potential adjusted water described in [9], in which the second pH adjustment is performed by adding at least one selected from the group consisting of hydrochloric acid, hydrofluoric acid, citric acid, acetic acid, formic acid and carbon dioxide to the pure water.
[12] The method for producing pH/oxidation-reduction potential adjusted water according to [9], wherein the oxidation-reduction potential is adjusted by adding at least one selected from the group consisting of hydrogen peroxide, ozone, and oxygen to the pure water.
[13] A method for producing pH/oxidation-reduction potential adjusted water described in [9], in which a first degassing treatment and a first gas dissolution treatment for dissolving an inert gas are sequentially performed on the pure water after the adjustment of the oxidation-reduction potential.
[14] A method for producing pH/oxidation-reduction potential adjusted water described in [9], in which a second degassing treatment and a second gas dissolution treatment for dissolving an inert gas are sequentially performed on the pure water after the second pH adjustment.
[15] The method for producing pH/oxidation-reduction potential adjusted water described in [9], wherein the semiconductor manufacturing process is a process for treating the surface of a semiconductor substrate having a wiring layer and an insulating layer made of copper or a copper alloy formed on the surface thereof before bonding the semiconductor substrate to another semiconductor substrate.
[16] A step of supplying the first adjusted water produced by the method for producing pH/oxidation-reduction potential adjusted water according to any one of [9] to [14] to a surface of a semiconductor substrate on which a wiring layer made of copper or a copper alloy and an insulating layer are formed, to form a copper oxide film on the surface of the wiring layer;
and a step of supplying the second regulated water to the surface of the semiconductor substrate to remove a copper oxide film formed on the surface of the wiring layer.

According to the pH/oxidation-reduction potential adjusted water producing apparatus of the present invention, the hydrogen peroxide contained in the pure water is removed by the hydrogen peroxide removing mechanism, and the pure water from which the hydrogen peroxide has been removed is supplied to the first branch line and the second branch line, respectively, and the pH and the oxidation-reduction potential are adjusted so as to obtain the desired pH and oxidation-reduction potential for each branch line, so that two types of pH/oxidation-reduction potential adjusted water can be prepared. The two types of pH/oxidation-reduction potential adjusted water are alternately circulated by the confluence line, so that digital etching of copper can be performed using these two types of pH/oxidation-reduction potential adjusted water as etching solutions. This makes it possible to dissolve a predetermined amount of wiring metal in the wiring manufacturing process of semiconductors that use copper as the wiring metal.
Therefore, according to the present invention, it is possible to provide an apparatus for producing pH/oxidation-reduction potential adjusted water that can dissolve a predetermined amount of wiring metal in a semiconductor manufacturing process that uses copper as the wiring metal.

In addition, according to the pH/oxidation-reduction potential adjusted water manufacturing device of the present invention, the first pH adjustment device adds at least one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, and tetrahydroammonium to the pure water, so that the pH of the first adjusted water can be adjusted to a range of 9 to 14.

In addition, according to the pH/oxidation-reduction potential adjusted water manufacturing device of the present invention, the second pH adjustment device adds at least one selected from the group consisting of hydrochloric acid, hydrofluoric acid, citric acid, acetic acid, formic acid, and carbon dioxide to the pure water, so that the pH of the second adjusted water can be adjusted to a range of 0 to 5.

In addition, according to the pH/oxidation-reduction potential adjusted water manufacturing device of the present invention, the oxidation-reduction potential adjusting device adds at least one selected from the group consisting of hydrogen peroxide, ozone, and oxygen to the pure water, so that the oxidation-reduction potential of the first adjusted water can be adjusted to the range of +0.1 to +1.0 V (vs Ag/AgCl).

In addition, according to the pH/oxidation-reduction potential adjusted water manufacturing apparatus of the present invention, a first degassing membrane device and a first gas dissolving membrane device are provided between the oxidation-reduction potential adjusting device and the first storage tank, and the first degassing membrane device reduces the dissolved oxygen in the first adjusted water, and the first gas dissolving membrane device dissolves the inert gas, thereby preventing an increase in dissolved oxygen in the first adjusted water and producing a first adjusted water in which the amount of dissolved oxygen has been reduced to a very low level.

In addition, according to the pH/oxidation-reduction potential adjusted water manufacturing apparatus of the present invention, a second degassing membrane device and a second gas dissolving membrane device are provided between the second pH adjustment device and the second storage tank, and the second degassing membrane device reduces the dissolved oxygen in the second adjusted water, and the second gas dissolving membrane device dissolves the inert gas, thereby preventing an increase in dissolved oxygen and producing second adjusted water in which the amount of dissolved oxygen has been reduced to a very low level.

In addition, according to the pH/oxidation-reduction potential adjusted water manufacturing device of the present invention, since the hydrogen peroxide content in the first adjustment water is 1000 ppm or less, the oxidation-reduction potential of the first adjustment water can be adjusted to a desired range. Furthermore, since the hydrogen peroxide content in the second adjustment water is 1000 ppm or less, it is possible to prevent the second adjustment water from being given excessive oxidizing power.

In addition, according to the pH/oxidation-reduction potential adjusted water manufacturing device of the present invention, the junction line is connected to a substrate processing device that processes the surface of a semiconductor substrate having a wiring layer and an insulating layer made of copper or a copper alloy formed on its surface before the semiconductor substrate is bonded to another semiconductor substrate, so that the surface of the semiconductor substrate can be appropriately processed, and the occurrence of wafer bonding defects can be reduced, for example, in the W2W process.

1 is a schematic diagram showing a pH/oxidation-reduction potential adjusted water producing apparatus according to a first embodiment of the present invention. 1 is a schematic diagram showing a pH/oxidation-reduction potential adjusted water producing apparatus according to a second embodiment of the present invention. FIG.

The following describes in detail an embodiment of the present invention, an apparatus and method for producing pH/oxidation-reduction potential adjusted water, with reference to the drawings.

First Embodiment
<pH/oxidation-reduction potential adjusted water manufacturing equipment>
Fig. 1 shows a pH/oxidation-reduction potential adjusted water producing apparatus according to a first embodiment of the present invention. In Fig. 1, the pH/oxidation-reduction potential adjusted water producing apparatus 1 is provided with a platinum group metal-supported resin column 3 serving as a hydrogen peroxide removal mechanism in a supply line 2 for pure water W. The supply line 2 for pure water branches into a first branch line 4 and a second branch line 5 downstream of the platinum group metal-supported resin column 3.

The first branch line 4 is joined by a pH adjuster injection line 41A (first pH adjuster) equipped with a liquid supply mechanism 41B connected to a pH adjuster tank 41, and an oxidation-reduction potential adjuster injection line 42A (oxidation-reduction potential adjuster) equipped with a liquid supply mechanism 42B connected to an oxidation-reduction potential adjuster tank 42. A first storage tank 43 for storing the first adjustment water is provided downstream of the oxidation-reduction potential adjuster injection line 42A, and in this embodiment, the first storage tank 43 is purged with an inert gas IG. The first branch line 4 extends from the first storage tank 43 to the junction line 6. The reference symbol 44 denotes an opening/closing valve provided on the first branch line 4 before the junction line 6.

The second branch line 5 also merges with a pH adjuster injection line 51A (second pH adjustment device) equipped with a liquid supply mechanism 51B that is connected to a pH adjuster tank 51. A second storage tank 53 that stores the second adjustment water is provided downstream of the pH adjuster injection line 51A, and in this embodiment, this second storage tank 53 is purged with an inert gas IG. The second branch line 5 then extends from this second storage tank 53 to the merging line 6. Reference numeral 54 denotes an opening/closing valve provided on the second branch line 5 just before the merging line 6.

The junction line 6 (supply line) is a line where the first branch line 4 and the second branch line 5 join together, and leads to the use point UP. Reference numeral 7 denotes an on-off valve provided midway along the junction line 6 leading to the use point UP.

An example of the use point UP to which the junction line 6 (supply line) reaches is a substrate processing apparatus for processing semiconductor substrates. An example of the substrate processing apparatus is a substrate processing apparatus that processes the surface of a semiconductor substrate, on whose surface a wiring layer made of copper or a copper alloy and an insulating layer are formed, in order to etch the wiring layer before bonding the semiconductor substrate to another semiconductor substrate.

In this embodiment, downstream of the pH adjuster injection line 41A and the oxidation-reduction potential adjuster injection line 42A of the first branch line 4, for example the first storage tank 43, are provided with an adjusted water quality monitoring mechanism such as a pH meter as a pH measuring means (not shown) and an ORP meter as an oxidation-reduction potential measuring means. In addition, downstream of the pH adjuster injection line 51A of the second branch line 5, for example the second storage tank 53, are provided with an adjusted water quality monitoring mechanism such as a pH meter as a pH measuring means (not shown). These pH meters and ORP meters are connected to a control device such as a personal computer. This control device is capable of controlling the amount of pH adjuster injected and the amount of oxidation-reduction potential adjuster injected based on the measured values of the pH meter and ORP meter.

<Pure water>
In this embodiment, the pure water W serving as the raw water is preferably ultrapure water having, 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.

<Hydrogen peroxide removal mechanism>
In this embodiment, a platinum group metal-supported resin column 3 is used as a hydrogen peroxide removal mechanism.

(Platinum group metal)
In this embodiment, examples of platinum group metals supported on the platinum group metal-supported resin used in the platinum group metal-supported resin column 3 include ruthenium, rhodium, palladium, osmium, iridium, and platinum. These platinum group metals can be used alone, or in combination of two or more, or as an alloy of two or more, or a refined product of a naturally occurring mixture can be used without separating it into single elements. Among these, platinum, palladium, and platinum/palladium alloys alone or a mixture of two or more of these can be preferably used because of their strong catalytic activity. Nano-sized particles of these metals can also be particularly preferably used.

(Carrier Resin)
In the platinum group metal-supported resin column 3, an ion exchange resin can be used as the carrier resin for supporting the platinum group metal. Among these, an anion exchange resin can be particularly preferably used. Since platinum-based metals are negatively charged, they are stably supported by the anion exchange resin and are not easily peeled off. The exchange group of the anion exchange resin is preferably in the OH type. The OH type anion exchange resin has an alkaline resin surface, which promotes the decomposition of hydrogen peroxide.

<pH adjuster injection lines 41A, 51A>
In this embodiment, the pH adjuster injection lines 41A and 51A are not particularly limited, and a general chemical injection device can be used. The pH adjuster tanks 41 and 51 may have an inert gas supply mechanism. When the pH adjuster is a liquid, a pump such as a diaphragm pump can be used, and it is desirable to purge the pH adjuster tanks 41 and 51 with an inert gas or to provide a mechanism for removing dissolved oxygen in the pH adjuster liquid in the tank using a degassing membrane. In addition, a pressurized pump in which the pH adjuster or the redox potential adjuster is placed in a sealed container together with an inert gas such as _N2 gas and these agents are pushed out by the pressure of the inert gas can also be suitably used. In addition, when the pH adjuster is a gas, a direct gas-liquid contact device such as a gas permeable membrane module or an ejector can be used.

<pH adjuster in pH adjuster injection line 41A>
In this embodiment, the pH adjuster injected from the pH adjuster tank 41 is not particularly limited, and at least one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, and tetrahydroammonium can be used to adjust the pH of the first adjusted water to 9 to 14. When the first adjusted water is used as cleaning water for a wafer on which copper is exposed as a wiring material, it is preferable to make it alkaline, but an alkali metal solution such as sodium hydroxide may not be appropriate because it contains metal components. Therefore, in this embodiment, it is most preferable to use ammonia, tetrahydroammonium, or the like. When the pH adjuster is one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, and tetrahydroammonium, it is preferable to inject the agent into the ultrapure water supply line by a pump or a pressurizing means using a sealed tank and an inert gas.

<pH adjuster in pH adjuster injection line 51A>
In this embodiment, the pH adjuster injected from the pH adjuster tank 51 is not particularly limited, and at least one selected from the group consisting of hydrochloric acid, hydrofluoric acid, citric acid, acetic acid, formic acid, and carbon dioxide can be used to adjust the pH of the second adjusted water to 0 to 5. When the pH adjuster is one selected from the group consisting of hydrochloric acid, hydrofluoric acid, citric acid, acetic acid, and formic acid, it is preferable to feed the agent to the ultrapure water supply line by a pressurizing means using a pump or a sealed tank and an inert gas. When the pH adjuster is carbon dioxide, it is preferable to add it by gas dissolution using a gas-permeable membrane module or a direct gas-liquid contact device using an ejector.

<Oxidation-reduction potential adjuster injection line 42A>
In this embodiment, the oxidation-reduction potential adjuster injection line 42A is not particularly limited, and a general chemical injection device can be used. The oxidation-reduction potential adjuster tank 42 may have an inert gas supply mechanism. When the oxidation-reduction potential adjuster is a liquid, a pump such as a diaphragm pump can be used, and it is desirable to purge the oxidation-reduction potential adjuster tank 42 with an inert gas or to provide a mechanism for removing dissolved oxygen in the pH adjuster liquid in the tank using a degassing membrane. In addition, a pressurized pump in which the oxidation-reduction potential adjuster is placed in a sealed container together with an inert gas such as _N2 gas and the agents are pushed out by the pressure of the inert gas can also be suitably used. In addition, when the oxidation-reduction potential adjuster is a gas, a direct gas-liquid contact device such as a gas permeable membrane module or an ejector can be used.

<Oxidation-reduction potential regulator>
In this embodiment, the redox potential adjuster injected from the redox potential adjuster tank 42 is not particularly limited, but at least one selected from the group consisting of hydrogen peroxide, ozone, and oxygen can be used to adjust the redox potential to a range of +0.1 to +1.0 V (vs Ag/AgCl). For example, when the first adjustment water is used as cleaning water for a wafer having exposed copper, it is preferable to adjust the redox potential to a positive value in order to suppress the elution of copper, and therefore it is preferable to use hydrogen peroxide water.

<Method of producing pH/oxidation-reduction potential adjusted water>
A method for producing pH/oxidation-reduction potential adjusted water using the pH/oxidation-reduction potential adjusted water producing apparatus 1 of this embodiment having the above-mentioned configuration will be described below.

In this embodiment, a hydrogen peroxide removal process, a first adjusted water production process, a second adjusted water production process, and a supply process are performed. The first adjusted water production process and the second adjusted water production process may be performed simultaneously, or the first adjusted water production process and the second adjusted water production process may be performed alternately in any order.

The hydrogen peroxide removal step is a step of removing hydrogen peroxide dissolved in the pure water from the pure water.
The first adjusted water production process performs a first pH adjustment and an adjustment of the redox potential on the pure water obtained after the hydrogen peroxide removal process to produce first adjusted water having a pH adjusted to 9 to 14 and a redox potential adjusted to +0.1 to +1.0 V (vs Ag/AgCl).
In the second adjusted water producing step, a second pH adjustment is performed on the pure water obtained after the hydrogen peroxide removing step, thereby producing second adjusted water whose pH is adjusted to a range of 0 to 5.
The supplying step alternately supplies the first adjusted water and the second adjusted water to the semiconductor manufacturing process through one supply line.

Below, we will explain the method for producing the first adjusted water and the method for producing the second adjusted water, and provide details of each step.

(Method for Producing First Adjusted Water)
Pure water W as raw water generally contains hydrogen peroxide at a level of several tens of ppb, and therefore, in order to accurately control the oxidation-reduction potential of the cleaning solution, it is necessary to remove the hydrogen peroxide from the pure water W in advance. Therefore, in the hydrogen peroxide removal step, the pure water W is supplied from a supply line 2 to a platinum group metal-supported resin column 3. In this platinum group metal-supported resin column 3, the hydrogen peroxide in the pure water W is decomposed and removed by the catalytic action of the platinum group metal, i.e., it functions as a hydrogen peroxide removal mechanism. The pure water W is then branched into a first branch line 4 and a second branch line 5.

Then, in the first branch line 4, a pH adjuster is injected from the pH adjuster tank 41 as the first pH adjustment. The addition of this pH adjuster can be set appropriately according to the desired pH, the flow rate of the first branch line 4, and the concentration of the pH adjuster. For example, when making the cleaning solution alkaline when cleaning a semiconductor having fine copper wiring, an amount of the pH adjuster that brings the cleaning solution to a pH range of 9 to 14 should be added.

Next, to adjust the redox potential, an redox potential adjuster is injected from the redox potential adjuster tank 42. The amount of redox potential adjuster added can be set appropriately according to the desired redox potential, the flow rate of the first branch line 4, and the concentration of the redox potential adjuster. For example, when cleaning a semiconductor having fine copper lines, an amount is added so that the redox potential of the cleaning solution falls within the range of +0.1 to +1.0 V (vs Ag/AgCl).

The first adjusted water W1 adjusted by the first branch line 4 preferably has a pH of 9 or more and 14 or less, and an oxidation-reduction potential of +0.1 V or more and +1.0 V or less (vs Ag/AgCl). In addition, the concentration of hydrogen peroxide in the first adjusted water W1 is preferably 1000 ppm or less.

Once the first adjusted water W1 is produced in this manner, it is stored in the first storage tank 43. Since the first storage tank 43 is purged with an inert gas, it is possible to prevent oxygen or carbon dioxide from dissolving in the first adjusted water W1 while the first adjusted water W1 is being stored, which would cause the pH and the redox potential to fluctuate. At this time, the control device controls the amount of pH adjuster added from the pH adjuster tank 41 and the amount of redox potential adjuster added from the redox potential adjuster tank 42 based on the measurement results of a pH meter and an ORP meter (not shown), thereby enabling a stable supply of the first adjusted water W1 adjusted to the desired pH and redox potential.

(Method for Producing Second Adjusted Water)
Meanwhile, the pure water W branched into the second branch line 5 is subjected to a second pH adjustment by injecting a pH adjuster from the pH adjuster tank 51 in the same manner as in the case of the first adjusted water W1, thereby producing a second adjusted water W2. At this time, the amount of pH adjuster added from the pH adjuster tank 51 is controlled by a control device based on the measurement result of a pH meter (not shown), thereby making it possible to stably supply the second adjusted water W2 having the desired pH.

It is desirable for the second adjustment water W2 to have a pH of 0 or more and 5 or less. In addition, it is desirable for the concentration of hydrogen peroxide in the second adjustment water W2 to be 1000 ppm or less.

The first adjusted water W1 and the second adjusted water W2 produced in this manner are then sent to the use point UP via the junction line 6 as a supply process. At this time, it is preferable to alternately send a fixed amount of the first adjusted water W1 and a fixed amount of the second adjusted water W2 in the junction line 6. To alternately send a fixed amount of the first adjusted water W1 and a fixed amount of the second adjusted water W2, the alternating liquid sending can be achieved by controlling the on-off valves 44, 54, and 7 using a control device not shown.

(Example of supplying pH/oxidation-reduction potential adjusted water)
Hereinafter, an example will be described in which the first adjusted water W1 and the second adjusted water W2 produced as described above are used for micro-etching of wiring made of copper.

In this embodiment, the first adjusted water and the second adjusted water are alternately supplied to the semiconductor manufacturing process through one supply line (junction line 6). Here, the semiconductor manufacturing process is preferably a process of treating the surface of a semiconductor substrate having a wiring layer and an insulating layer made of copper or a copper alloy formed on the surface thereof before bonding the semiconductor substrate to another semiconductor substrate. More specifically, it is preferably a process of etching the copper wiring formed on the surface of the semiconductor substrate by a digital etching method.

A technique called digital etching is used for micro-etching wiring made of copper or copper alloy. This is a technique in which the metal is dissolved in stages by repeatedly oxidizing the metal surface and dissolving the oxide film. When micro-etching copper using digital etching, in the first step, a copper oxide film is formed on the surface of the copper wiring using the first adjusted water without dissolving the copper, and in the second step, it is necessary to dissolve only the copper oxide film formed in the first step using the second adjusted water without dissolving the copper.

According to the Pourbaix diagram, which shows which chemical species of metals are most stable in an aqueous solution under certain [potential-pH] conditions, copper becomes passive and difficult to dissolve under alkaline conditions, especially in the pH range of 9 to 12, and the copper dissolution rate is minimized by adding about 10 to 1000 ppm of hydrogen peroxide to an alkaline solution of pH 9 to 12. However, it is known that when the pH is 12 or higher and the hydrogen peroxide concentration is 100 to 1000 ppm or higher, the copper dissolution rate is about 50 times faster than when hydrogen peroxide is not added. Therefore, in order to oxidize the surface while preventing copper dissolution in the first step of digital etching, it is necessary to more strictly control the pH and redox potential of the first adjustment water.

On the other hand, according to the Pourbaix diagram, under acidic conditions, behavior such as dissolution and passivation differs depending on the pH and redox potential of the aqueous solution. In order to micro-etch a specified amount of copper within a specified time, it is necessary to accelerate the removal rate of the copper oxide film in the second step, and to do so, the pH of the second adjustment water must be made less than 5.

In view of these considerations, in order to micro-etch a specified amount of copper within a specified time while suppressing the occurrence of pattern loading, the first adjusted water W1 is adjusted so that the pH is in the range of 9 to 14 and the redox potential is 0.1 to 1.0 V (vs Ag/AgCl) (hydrogen peroxide is about 10 to 1000 ppm) so that copper dissolution is least likely to occur, and is then supplied from the first branch line 4 to the substrate processing apparatus, which is the use point UP, for the first cleaning step. This forms an oxide film on the copper surface without dissolving the copper. At this time, the opening/closing valve 54 of the second branch line is closed.

Next, in order to extremely finely etch a predetermined amount of copper within a predetermined time, hydrofluoric acid, citric acid, acetic acid, formic acid, and carbon dioxide are added to the treatment liquid so that the pH of the treatment liquid is less than 5 in order to accelerate the removal rate of the copper oxide film, and second adjusted water W2 is produced. Then, the on-off valve 44 of the first branch line 4 is closed to stop the supply of first adjusted water W1, and the on-off valve 54 of the second branch line 5 is opened to supply second adjusted water W2 from the second branch line 5 to the substrate treatment device, which is the use point UP, to perform the second cleaning process. This extremely finely etches a predetermined amount of copper.

In this way, extremely small etching of semiconductor wiring made of copper or copper alloy can be performed efficiently and in a short time. This allows the surface of the semiconductor substrate to be properly processed, and reduces the occurrence of wafer bonding defects, for example, in the W2W process.

Second Embodiment
<pH/oxidation-reduction potential adjusted water manufacturing equipment>
FIG. 2 shows a pH/oxidation-reduction potential adjusted water producing apparatus 11 according to a second embodiment of the present invention, in which the same components as those in the first embodiment described above are given the same reference numerals and detailed descriptions thereof are omitted.

In FIG. 2, the pH/oxidation-reduction potential adjusted water production apparatus 11 includes a first degassing membrane device 47 having a vacuum pump 47A downstream of the oxidation-reduction potential adjuster tank 42 of the first branch line 4, and a first gas dissolving membrane device 48 that dissolves an inert gas. Also, a second degassing membrane device 57 having a vacuum pump 57A downstream of the pH adjuster tank 51 of the second branch line 5, and a second gas dissolving membrane device 58 that dissolves an inert gas.

The first degassing membrane device 47 and the second degassing membrane device 57 are membrane-type degassing devices, and vacuum pumps (VP) 47A and 57A are connected to the gas phase side of the degassing membrane. These degassing membrane devices 47 and 57 can be configured to pass the first adjustment water W1 or the second adjustment water W2 through one side (liquid phase side) of the degassing membrane, respectively, and suction the other side (gas phase side) with the vacuum pumps (VP) 47A and 57A, thereby allowing dissolved gases such as dissolved oxygen to pass through the degassing membrane and migrate to the gas phase chamber side for removal. The degassing membrane may be any membrane that allows gases such as oxygen, nitrogen, and steam to pass through but does not allow water to pass through, such as silicone rubber, polytetrafluoroethylene, polyolefin, and polyurethane. Various commercially available degassing membranes can be used.

The first gas-dissolving film device 48 and the second gas-dissolving film device 58 are each equipped with a gas-dissolving film, and the gas-phase chamber side of the gas-dissolving film is connected to a source of _N2 gas as an inert gas. These gas-dissolving film devices 48 and 58 flow the first adjusting water W1 or the second adjusting water W2 to one side (liquid phase side) of the gas-dissolving film, respectively, and supply _N2 gas to the other side (gas phase side), thereby dissolving the inert gas in the first adjusting water W1 and the second adjusting water W2, respectively. Note that the inert gas is not limited to _N2 gas, and argon and helium can also be suitably used.

<Method of producing pH/oxidation-reduction potential adjusted water>
A method for producing pH/oxidation-reduction potential adjusted water using the apparatus for producing pH/oxidation-reduction potential adjusted water of this embodiment having the above-mentioned configuration will be described below.

(Method for Producing First Adjusted Water)
Pure water W as raw water generally contains hydrogen peroxide at a level of several tens of ppb, and therefore, in order to accurately control the oxidation-reduction potential of the cleaning solution, it is necessary to remove the hydrogen peroxide from the pure water W in advance. Therefore, first, the pure water W is supplied from a supply line 2 to a platinum group metal-supported resin column 3. In this platinum group metal-supported resin column 3, the hydrogen peroxide in the pure water W is decomposed and removed by the catalytic action of the platinum group metal, that is, it functions as a hydrogen peroxide removal mechanism. The pure water W is then branched into a first branch line 4 and a second branch line 5.

Then, in the first branch line 4, a pH adjuster is injected from the pH adjuster tank 41. The addition of this pH adjuster can be set appropriately according to the desired pH, the flow rate in the first branch line 4, and the concentration of the pH adjuster. For example, when cleaning a semiconductor having fine copper wires, an amount is added that brings the pH of the first adjusted water W1 to a range of 9 to 14.

Next, the redox potential regulator is injected from the redox potential regulator tank 42. The amount of the redox potential regulator added can be set appropriately according to the desired redox potential, the flow rate of the first branch line 4, and the concentration of the redox potential regulator. For example, when cleaning a semiconductor having fine copper wires, an amount is added that brings the redox potential of the first adjustment water W1 to a range of 0.1 to 1.0 V (vs Ag/AgCl).

Next, the first adjusted water W1 after the oxidation-reduction potential adjustment is degassed in the first degassing membrane device 47. In the first degassing membrane device 47, the first adjusted water W1 is passed through the liquid phase chamber side of the liquid phase chamber and the gas phase chamber formed by the hydrophobic gas-permeable membrane, and the gas phase chamber is depressurized by the vacuum pump (VP) 47A, so that dissolved gases such as dissolved oxygen contained in the first adjusted water W1 are removed by transferring them to the gas phase chamber through the hydrophobic gas-permeable membrane. This makes it possible to reduce the dissolved oxygen concentration of the first adjusted water W1 to a very low level. In addition, by degassing the pH adjuster and the oxidation-reduction potential adjuster after making them into the first adjusted water W1 rather than degassing them directly, it is possible to reduce the risk of leakage of chemicals when vacuum degassing these chemicals.

Next, an inert gas is supplied to the first adjusted water W1 after the degassing process by the first gas dissolving membrane device 48 to stabilize the properties of the first adjusted water W1, thereby producing a stabilized first adjusted water W1.

Once the first adjusted water W1 is produced in this manner, it is stored in the first storage tank 43. Since this first storage tank 43 is purged with an inert gas, it is possible to prevent oxygen or carbon dioxide from dissolving in the first adjusted water W1 while the first adjusted water W1 is being stored, which would cause fluctuations in the pH or redox potential.

(Method for Producing Second Adjusted Water)
On the other hand, the pure water branched off to the second branch line 5 can be treated in the same manner as the first adjusted water W1 by injecting a pH adjuster from a pH adjuster tank 51, degassing it in a second degassing membrane device 57, and then dissolving an inert gas in a second gas dissolution membrane device 58 to produce a second adjusted water W2.

The first adjusted water W1 and the second adjusted water W2 thus produced are then sent to the substrate processing apparatus, which is the use point UP, via the junction line 6. At this time, it is preferable to alternately send a fixed amount of the first adjusted water W1 and a fixed amount of the second adjusted water W2 in the junction line 6. To alternately send a fixed amount of the first adjusted water W1 and a fixed amount of the second adjusted water W2, the alternating liquid sending can be achieved by controlling the on-off valves 44, 54, and 7 using a control device not shown.

According to the pH/oxidation-reduction potential adjusted water manufacturing device and manufacturing method of this embodiment, two types of pH/oxidation-reduction potential adjusted water with different pH and oxidation-reduction potential can be manufactured. By combining these different pH/oxidation-reduction potential adjusted waters, it becomes possible to wash semiconductors with cleaning water with a pH and oxidation-reduction potential that can suppress copper dissolution, and cleaning water with a pH and oxidation-reduction potential that can finely adjust copper dissolution, and it becomes possible to dissolve a predetermined amount of wiring metal in the semiconductor wiring manufacturing process that uses copper as the wiring metal. This makes it possible to reduce the occurrence of wafer bonding defects in the W2W process, for example.

[Example 1]
(Preparation of first adjusted water and second adjusted water)
Using the pH/oxidation-reduction potential adjusted water manufacturing apparatus shown in Figure 1, ammonia was added from the pH adjuster tank 41 and hydrogen peroxide water was added from the oxidation-reduction potential adjuster tank 42 to the pure water W in the first branch line 4, and an ammonia/hydrogen peroxide aqueous solution (ammonia concentration: 2 ppm, pH 9 (23°C), hydrogen peroxide concentration: 1000 ppm, oxidation-reduction potential: +0.28 V) was produced as the first adjusted water W1.
In the second branch line, hydrochloric acid was added to the pure water W from the pH adjuster tank 51 to produce an aqueous hydrochloric acid solution (hydrochloric acid concentration: 1000 ppm, pH 2 (23° C.), hydrogen peroxide concentration: 0 ppb) as the second adjusted water W2.

(Digital Etch Processing Test)
A 20 mm x 20 mm rectangular test piece was cut out from a wafer with a 300 mm diameter copper wiring (100 μmL/S pattern) and an insulating film. The test piece was immersed in the first adjusted water and the second adjusted water at 23° C. for 20 minutes each, and then the test pieces were bonded together. As a result, no bonding defects were observed in the copper wiring and the insulating film with an optical microscope, which indicated good results.

[Example 2]
(Preparation of first adjusted water and second adjusted water)
As the first adjusted water W1, an aqueous ammonia/hydrogen peroxide solution (ammonia concentration: 10 ppm, pH 10 (23° C.), hydrogen peroxide concentration: 1000 ppm, oxidation-reduction potential: +0.20 V) was produced.
In the second branch line, hydrofluoric acid was added to the pure water W from the pH adjuster tank 51 to produce an aqueous hydrofluoric acid solution (hydrofluoric acid concentration: 1000 ppm, pH 2 (23° C.), hydrogen peroxide concentration: 0 ppb) as the second adjusted water W2.

(Digital Etch Processing Test)
A 20 mm x 20 mm rectangular test piece was cut out from a wafer with a 300 mm diameter copper wiring (100 μmL/S pattern) and an insulating film. The test piece was immersed in the first adjusted water and the second adjusted water at 23° C. for 20 minutes each, and then the test pieces were bonded together. As a result, no bonding defects were observed in the copper wiring and the insulating film with an optical microscope, which indicated good results.

[Example 3]
(Preparation of first adjusted water and second adjusted water)
As the first adjusted water W1, an aqueous ammonia/hydrogen peroxide solution (ammonia concentration: 100 ppm, pH 11 (23° C.), hydrogen peroxide concentration: 1000 ppm, oxidation-reduction potential: +0.18 V) was produced.
In the second branch line, sulfuric acid was added to the pure water W from the pH adjuster tank 51 to produce an aqueous sulfuric acid solution (sulfuric acid concentration: 1000 ppm, pH 2 (23° C.), hydrogen peroxide concentration: 0 ppb) as the second adjusted water W2.

(Digital Etch Processing Test)
A 20 mm x 20 mm rectangular test piece was cut out from a wafer with a 300 mm diameter copper wiring (100 μmL/S pattern) and an insulating film. The test piece was immersed in the first adjusted water and the second adjusted water at 23° C. for 20 minutes each, and then the test pieces were bonded together. As a result, no bonding defects were observed in the copper wiring and the insulating film with an optical microscope, which indicated good results.

[Example 4]
(Preparation of first adjusted water and second adjusted water)
In the first branch line 4, sodium hydroxide was added from the pH adjuster tank 41 and hydrogen peroxide water was added from the redox potential adjuster tank 42 to the pure water W, thereby producing a sodium hydroxide/hydrogen peroxide aqueous solution (sodium hydroxide concentration: 10 ppm, pH 10 (23° C.), hydrogen peroxide concentration: 1000 ppm, redox potential: +0.21 V) as the first adjusted water W1.
In the second branch line, acetic acid was added from the pH adjuster tank 51 to the pure water W to produce an aqueous acetic acid solution (acetic acid concentration: 1000 ppm, pH 3 (23° C.), hydrogen peroxide concentration: 0 ppb) as the second adjusted water W2.

(Digital Etch Processing Test)
A 20 mm x 20 mm rectangular test piece was cut out from a wafer with a 300 mm diameter copper wiring (100 μmL/S pattern) and an insulating film. The test piece was immersed in the first adjusted water and the second adjusted water at 23° C. for 20 minutes each, and then the test pieces were bonded together. As a result, no bonding defects were observed in the copper wiring and the insulating film with an optical microscope, which indicated good results.

[Example 5]
(Preparation of first adjusted water and second adjusted water)
As the first adjusted water W1, an aqueous ammonia/hydrogen peroxide solution (ammonia concentration: 10 ppm, pH 10 (23° C.), hydrogen peroxide concentration: 1000 ppm, oxidation-reduction potential: +0.20 V) was produced.
In the second branch line, hydrochloric acid was added to the pure water W from the pH adjuster tank 51 to produce an aqueous hydrochloric acid solution (hydrochloric acid concentration: 10%, pH 1 (23° C.), hydrogen peroxide concentration: 100 ppb) as the second adjusted water W2.

(Digital Etch Processing Test)
A 20 mm x 20 mm rectangular test piece was cut out from a wafer with a 300 mm diameter copper wiring (100 μmL/S pattern) and an insulating film. The test piece was immersed in the first adjusted water and the second adjusted water at 23° C. for 20 minutes each, and then the test pieces were bonded together. As a result, no bonding defects were observed in the copper wiring and the insulating film with an optical microscope, which indicated good results.

[Example 6]
(Preparation of first adjusted water and second adjusted water)
As the first adjusted water W1, an aqueous ammonia solution (ammonia concentration: 10 ppm, pH 10 (23° C.), hydrogen peroxide concentration: 0 ppm, oxidation-reduction potential: +0.37 V) was produced.
In the second branch line, hydrochloric acid was added from the pH adjuster tank 51 to the pure water W to produce an aqueous hydrochloric acid solution (hydrochloric acid concentration: 1 ppm, pH 5 (23° C.), hydrogen peroxide concentration: 0 ppb) as the second adjusted water W2.

(Digital Etch Processing Test)
A 20 mm x 20 mm rectangular test piece was cut out from a wafer with a 300 mm diameter copper wiring (100 μmL/S pattern) and an insulating film. The test pieces were immersed in the first adjusted water and the second adjusted water at 23° C. for 20 minutes each, and then the test pieces were bonded together. As a result, poor bonding was observed in some parts of the copper wiring and the insulating film using an optical microscope, so the result was good.

[Comparative Example 1]
A 20 mm x 20 mm rectangular test piece was cut out from a wafer with a 300 mm diameter copper wiring (100 μm L/S pattern) and an insulating film. The test pieces were bonded together without any treatment. As a result, poor bonding was observed in the copper wiring and the insulating film using an optical microscope, and the test pieces were found to be defective.

[Comparative Example 2]
(Preparation of first adjusted water and second adjusted water)
As the first adjusted water W1, an aqueous hydrogen peroxide solution (pH 5 (23° C.), hydrogen peroxide concentration: 3%, oxidation-reduction potential: +0.57 V) was produced.
In addition, an aqueous hydrofluoric acid solution (hydrofluoric acid concentration: 0.05%, pH 3 (23° C.), hydrogen peroxide concentration: 10 ppb) was produced as the second adjusted water W2.

Then, a 20 mm x 20 mm rectangular test piece was cut out from the wafer with 300 mm diameter copper wiring (100 μmL/S pattern) and insulating film. The test pieces were immersed in the first adjusted water and the second adjusted water at 23°C for 20 minutes each, and then the test pieces were bonded together. As a result, poor bonding was observed in the copper wiring and insulating film using an optical microscope, indicating that the test pieces were defective.

[Comparative Example 3]
Sodium hydroxide was dissolved in pure water to prepare an aqueous sodium hydroxide solution (sodium hydroxide concentration: 1000 ppm, pH 13 (23° C.), oxidation-reduction potential: +0.05 V).

Then, a rectangular test piece measuring 20 mm x 20 mm was cut out from the wafer with 300 mm diameter copper wiring (100 μmL/S pattern) and insulating film. The test pieces were immersed in an aqueous sodium hydroxide solution at 23°C for 20 minutes, and then the test pieces were bonded together. As a result, poor bonding was observed in the copper wiring and insulating film using an optical microscope, indicating that the test pieces were defective.

The results of the examples and comparative examples are shown in Table 1.

1...pH/oxidation-reduction potential adjusted water production device, 2...supply line, 3...platinum group metal supported resin column (hydrogen peroxide removal mechanism), 4...first branch line, 5...second branch line, 6...junction line, 41A...pH adjuster injection line (first pH adjuster), 42A...oxidation-reduction potential adjuster injection line (oxidation-reduction potential adjuster), 43...first storage tank, 47...first degassing membrane device, 48...first gas dissolving membrane device, 51A...pH adjuster injection line (second pH adjuster), 53...second storage tank, 57...second degassing membrane device, 58...second gas dissolving membrane device.

Claims (16)

a hydrogen peroxide removal mechanism for removing hydrogen peroxide dissolved in the pure water from the pure water;
a first branch line and a second branch line branched off at a downstream side of the hydrogen peroxide removal mechanism;
a junction line formed by junction of the first branch line and the second branch line,
a first pH adjusting device for adjusting a pH of the pure water, an oxidation-reduction potential adjusting device for adjusting an oxidation-reduction potential of the pure water, and a first storage tank are arranged in this order in the first branch line;
a second pH adjusting device for adjusting a pH of the pure water and a second storage tank are arranged in this order in the second branch line;
The confluence line is configured to alternately circulate first adjusted water, the pH of which has been adjusted to a range of 9 to 14 and the redox potential of which has been adjusted to a range of 0.1 to 1.0 V (vs Ag/AgCl) by the first branch line, and second adjusted water, the pH of which has been adjusted to a range of 0 to 5 by the second branch line. The apparatus for producing pH/oxidation-reduction potential adjusted water according to claim 1, wherein the first pH adjustment device adds at least one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, and tetrahydroammonium to the pure water. The pH/oxidation-reduction potential adjusted water manufacturing device according to claim 1, wherein the second pH adjustment device adds at least one selected from the group consisting of hydrochloric acid, hydrofluoric acid, citric acid, acetic acid, formic acid, and carbon dioxide to the pure water. The pH/oxidation-reduction potential adjusted water manufacturing device according to claim 1, wherein the oxidation-reduction potential adjustment device adds at least one selected from the group consisting of hydrogen peroxide, ozone, and oxygen to the pure water. The pH/oxidation-reduction potential adjusted water manufacturing apparatus according to claim 1, further comprising a first degassing membrane device and a first gas dissolving membrane device for dissolving an inert gas between the oxidation-reduction potential adjustment device and the first storage tank. The pH/oxidation-reduction potential adjusted water manufacturing apparatus according to claim 1, further comprising a second degassing membrane device and a second gas dissolving membrane device for dissolving an inert gas between the second pH adjusting device and the second storage tank. The apparatus for producing pH/oxidation-reduction potential adjusted water according to claim 1, wherein the hydrogen peroxide content in the first adjusted water and the second adjusted water is 1000 ppm or less. The pH/oxidation-reduction potential adjusted water manufacturing apparatus according to claim 1, wherein the junction line is connected to a substrate processing apparatus that processes the surface of a semiconductor substrate having a wiring layer and an insulating layer made of copper or a copper alloy formed on the surface thereof before the semiconductor substrate is bonded to another semiconductor substrate. a hydrogen peroxide removal step of removing hydrogen peroxide dissolved in the pure water from the pure water;
a first adjusted water producing step of producing a first adjusted water having a pH adjusted to 9 to 14 and an oxidation-reduction potential adjusted to +0.1 to +1.0 V (vs. Ag/AgCl) by performing a first pH adjustment and an oxidation-reduction potential adjustment on the pure water after the hydrogen peroxide removal step;
a second adjusted water producing step of producing a second adjusted water having a pH adjusted to a range of 0 to 5 by performing a second pH adjustment on the pure water after the hydrogen peroxide removing step;
a supplying step of alternately supplying the first adjusted water and the second adjusted water to a semiconductor manufacturing process through one supply line. The method for producing pH/oxidation-reduction potential adjusted water according to claim 9, wherein the first pH adjustment is performed by adding at least one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, and tetrahydroammonium to the pure water. The method for producing pH/oxidation-reduction potential adjusted water according to claim 9, wherein the second pH adjustment is performed by adding at least one selected from the group consisting of hydrochloric acid, hydrofluoric acid, citric acid, acetic acid, formic acid, and carbon dioxide to the pure water. The method for producing pH/oxidation-reduction potential adjusted water according to claim 9, wherein the oxidation-reduction potential is adjusted by adding at least one selected from the group consisting of hydrogen peroxide, ozone, and oxygen to the pure water. The method for producing pH/oxidation-reduction potential adjusted water according to claim 9, wherein the pure water after the oxidation-reduction potential adjustment is subjected to a first degassing process and a first gas dissolution process for dissolving an inert gas in sequence. The method for producing pH/oxidation-reduction potential adjusted water according to claim 9, wherein the pure water after the second pH adjustment is subjected to a second degassing process and a second gas dissolution process for dissolving an inert gas in sequence. The method for producing pH/oxidation-reduction potential adjusted water according to claim 9, wherein the semiconductor manufacturing process is a process for treating the surface of a semiconductor substrate having a wiring layer and an insulating layer made of copper or a copper alloy formed on the surface thereof before bonding the semiconductor substrate to another semiconductor substrate. a step of supplying the first adjusted water produced by the method for producing pH/oxidation-reduction potential adjusted water according to any one of claims 9 to 14 to a surface of a semiconductor substrate on which a wiring layer made of copper or a copper alloy and an insulating layer are formed, to form a copper oxide film on the surface of the wiring layer;
and a step of supplying the second regulated water to the surface of the semiconductor substrate to remove a copper oxide film formed on the surface of the wiring layer.

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