KR20000068218A - Method and device for washing electronic parts member, or the like - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method and a cleaning apparatus for electronic component members, wherein electronic component members such as silicon wafers are washed with washing water, and the washing water is obtained by dissolving hydrogen gas or ozone gas in ultrapure water. With a positive acid reduction reduction potential, the washing power is increased by such washing water, and washing can be made more effective by adjusting the pH of the washing water.

Description

TECHNICAL AND DEVICE FOR WASHING ELECTRONIC PARTS MEMBER, OR THE LIKE

In the manufacturing process of electronic component members, such as LSI, it is calculated | required to make very clean the surface. For example, LSI forms an insulating film of silicon oxide on a silicon wafer, and subsequently forms a resist layer on the film in a predetermined pattern, and removes the insulating film of a portion where the resist layer is not formed by etching or the like. After the silicon is exposed and the surface is cleaned, a p-type or n-type element is introduced according to the purpose, and the process of forming a metal wiring such as aluminum is repeated (lithography process). When introducing an n-type element or embedding metal wiring, if foreign matter such as fine particles, metal, organic matter, or natural oxide film is attached to the surface of the metal silicon, contact failure or increase in contact resistance between the metal silicon and the metal wiring The characteristics of the device may be poor. For this reason, in the LSI manufacturing process, the cleaning process of the silicon wafer surface is a very important process for obtaining a high performance device, and it is necessary to remove the adhesion impurities on the silicon wafer as much as possible.

Conventionally, cleaning of a silicon wafer is performed by combining a cleaning solution with a sulfuric acid / hydrogen peroxide mixed solution, a hydrochloric acid / hydrogen peroxide mixed solution, a hydrofluoric acid solution, an aluminum fluoride solution, and the like with ultrapure water, and the flatness at the atomic level of the silicon wafer surface. Without damage, organic matter, fine particles, metals, natural oxide films and the like adhered to the silicon wafer surface are removed.

The following (1)-(13) is a specific example of the conventional washing | cleaning process of a silicon wafer.

(1) sulfuric acid and hydrogen peroxide cleaning process; It wash | cleaned for 10 minutes at 130 degreeC with the mixed solution of sulfuric acid: hydrogen peroxide = 4: 1 (volume ratio).

(2) ultrapure water washing process; 10 minutes washing with ultrapure water.

(3) hydrofluoric acid washing step; 1 minute wash with 0.5% hydrofluoric acid.

(4) ultrapure water washing process; 10 minutes washing with ultrapure water.

(5) Ammonia / hydrogen peroxide washing step; ammonia water: hydrogen peroxide water: ultrapure water = 0.05: 1: 5 (volume ratio) Washing | cleaning for 10 minutes at 80 degreeC.

(6) ultrapure water washing process; 10 minutes washing with ultrapure water.

(7) hydrofluoric acid washing step; 1 minute wash with 0.5% hydrofluoric acid.

(8) Ultrapure water washing step: 10 minutes washing with ultrapure water.

(9) hydrochloric acid and hydrogen peroxide water washing step; 10 minutes wash | cleaning at 80 degreeC with the mixed solution of hydrochloric acid: hydrogen peroxide water: ultrapure water = 1: 1: 6 (volume ratio).

(10) ultrapure water washing process; 10 minutes washing with ultrapure water.

(11) hydrofluoric acid washing step; 1 minute wash with 0.5% hydrofluoric acid.

(12) ultrapure water washing process; 10 minutes washing with ultrapure water.

(13) spin drying or IPA steam drying

In the step (1), the organic matter adhered to the surface of the silicon wafer is mainly removed. In step (5), the fine particles adhering to the surface of the silicon wafer are mainly removed. In the process of (9), metal impurities mainly on the surface of the silicon wafer are removed.

In addition, the process of (3), (7), (11) is performed in order to remove the natural oxide film of a silicon wafer surface. Moreover, the washing | cleaning liquid of each said process often has the capability of removing contaminants other than the above-mentioned main purpose. For example, the sulfuric acid and hydrogen peroxide mixed solution used in the step (1) has a strong action of removing metallic impurities in addition to organic matter. For this reason, in addition to the method of removing other impurities by the above-mentioned cleaning liquids, there is also a method in which a plurality of impurities are removed by one type of cleaning liquid.

In the cleaning process of a silicon wafer, as a method of bringing a cleaning liquid or ultrapure water into contact with the surface of the silicon wafer, a method called a batch cleaning method is generally employed in which a plurality of silicon wafers are immersed in a cleaning tank in which the cleaning liquid or ultrapure water is stored. However, in order to prevent contamination of the cleaning liquid, the cleaning liquid is circulated and washed, and the rinsing method using ultrapure water after treatment with the cleaning liquid is performed while supplying the ultrapure water from the bottom of the cleaning tank and overflowing it from the top of the cleaning tank. The overflow rinse method and the quick dump rinse system which store ultrapure water in a cleaning tank until the whole surface of a wafer is immersed in ultrapure water, and discharge ultrapure water from the bottom of a cleaning tank at once, etc. are also employ | adopted. Recently, a so-called single wafer rinse has also been adopted, such as a method of cleaning by spraying a cleaning liquid or ultrapure water in a shower shape on the wafer surface, or by cleaning the wafer by spraying the cleaning liquid or ultrapure water in the center thereof at a high speed. have.

Cleaning with ultrapure water performed after each cleaning step with the cleaning liquid is performed to rinse (rinse) the cleaning liquid or the like remaining on the wafer surface. For this reason, ultrapure water used for rinsing is used to remove fine particles, colloidal substances, organic matter, metal ions, anions, dissolved oxygen, etc. to an extreme level. This ultrapure water is also used as a solvent for the cleaning liquid.

Therefore, the density of LSI has recently increased dramatically. Therefore, although the lithography process in the LSI manufacturing process was initially several times, the number of lithography processes has increased from 20 to 30 times, and the number of wafer cleaning has also increased with the increase of the lithography process. . For this reason, the cost of the raw material of the cleaning liquid and ultrapure water used for cleaning the wafer, the processing cost of the used cleaning liquid and ultrapure water, and the cost of discharging the cleaning liquid gas generated in the clean room by the high temperature cleaning process in the clean room are increased. This is leading to a rise in product costs.

In the LSI manufacturing process, the removal of fine particles from the wafer surface is a particularly important problem because the fine particles adhered to the surface of the silicon wafer significantly lower the production rate of the LSI. Conventionally, a mixed solution of ammonia and hydrogen peroxide is used to clean fine particles adhering to a silicon wafer surface. However, although ammonia and hydrogen peroxide react to produce species other than these, it is not clear what kind of cleaning effect these species exhibit, but the science of how to obtain the desired cleaning effect by the composition and ratio of the ammonia and hydrogen peroxide mixed solution is obtained. No intellectual knowledge is available. For this reason, it is a reality that a high concentration of ammonia / hydrogen peroxide mixed solution is used more than necessary in order to reliably clean and remove fine particles on the wafer surface. In other words, in order to remove the fine particles on the wafer surface, etching may be usually performed using an alkaline solution, but it is necessary to prevent the fine particles once separated from the wafer surface from reattaching to the wafer surface. In order to prevent reattachment, the surface potentials of the wafer surface and the fine particles may be equalized and electrically repelled. For this purpose, the pH of the cleaning liquid has to be increased to make it highly alkaline. In addition, when the strongly alkaline chemical liquid is used, the surface of the wafer becomes rougher than necessary, so that it is necessary to add hydrogen peroxide water to the cleaning liquid and to form an oxide film on the surface under the action of hydrogen peroxide water to prevent the roughness of the wafer surface. As a result, there is a problem in that the consumption of a large amount of chemicals more than necessary, accompanied by an increase in the amount of rinsing ultrapure water used or an increase in wastewater treatment cost.

As described above, in the conventional cleaning process, the natural oxide film formed on the surface of the silicon wafer is removed by hydrofluoric acid cleaning, followed by rinsing with ultrapure water. However, when this rinsing by ultrapure water was performed, there existed a possibility that the following some problems might arise.

First, in order to prevent oxidation of the silicon wafer surface by dissolved oxygen, what degassed the dissolved oxygen concentration to 10 ppm or less is used as ultrapure water. However, in general, since the cleaning tank does not have an airtight structure, oxygen gas in the atmosphere is dissolved in ultrapure water in an instant in the cleaning tank (the dissolved oxygen concentration rises to about 100 ppm). When the cleaning is performed using such ultrapure water, the surface of the silicon wafer is easily oxidized. In particular, in the case of n + silicon, which is susceptible to oxidation, an oxide film of several angstroms is easily formed.

Moreover, in order to solve the said problem caused by the dissolution of oxygen gas in air | atmosphere into ultrapure water, it is also conceivable to comprise a washing tank in an airtight structure. Even in this case, 10 to ⁷ moles of hydroxyl ions are present in the neutral ultrapure water, and the surface of the silicon wafer is etched by the hydroxyl ions, and there is a problem of easily causing surface roughness to reach a depth of several angstroms. In addition, there is a problem that the silicon etched by the hydroxide ions adheres to the silicon wafer surface and the silicon wafer surface is blurred.

Further, in the cleaning step of the LSI or the like, organic molecules adhered to the silicon wafer surface deteriorate the performance of the LSI and significantly reduce the production rate of the LSI. In addition, if the organic material is in the form of a film, and metal impurities or fine particles adhere to the inside of the film or a natural oxide film is formed, the metal impurities, the fine particles, the natural oxide film, etc. are sufficiently cleaned even if the hydrofluoric acid washing, the hydrochloric acid hydrogen peroxide solution, the ammonia hydrogen peroxide solution, etc. are performed. There was a problem that could not be removed.

For this reason, it is common for the washing process conventionally performed to remove organic substance first. Conventionally, the method of washing sulfuric acid hydrogen peroxide solution like the above example is mainly adopted for removal of an organic substance. However, since sulfuric acid hydrogen peroxide solution with a high concentration of several ten percent is used, a large amount of chemicals (sulfuric acid and hydrogen peroxide water) are used, and a large amount of ultrapure water is required because rinsing after washing is performed. This not only increases the cost of chemicals used to prepare sulfuric acid peroxide, but also requires large-scale waste and wastewater treatment facilities for the disposal of ultra-pure water used for the treatment or rinsing of spent hydrogen peroxide solution. Since installation costs and operating costs also increase, there is a problem of raising the manufacturing cost of the product. In addition, since sulfuric acid peroxide is washed at a high temperature, not only a heat source is required but also a gas of the treatment chemical is generated, and thus, a chemical gas must be discharged in the clean room, and as a result, a cost for heat source or exhaust gas is also a problem. There was.

On the other hand, in recent years, the method of washing | cleaning with ultrapure water which melt | dissolved ozone gas and removing organic substance also begins to become practical, for example, the method of washing | cleaning for 10 minutes at room temperature with ultrapure water which melt | dissolved 2-10 ppm ozone gas is also proposed. However, the method of washing at room temperature with ultrapure water dissolved in ozone gas is difficult to remove the organics sufficiently in the case where the amount of adhesion of organic matters or the organic matters is hardly decomposable, and the organic matters may remain even after long time cleaning. There was.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cleaning method and a cleaning apparatus for electronic component members such as semiconductor substrates, glass substrates, electronic components, or manufacturing apparatus components thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the structure of the washing | cleaning apparatus of 1st and 2nd Example of this invention,

2 is a view showing a configuration of a gas dissolving tank preferable in the present invention;

3 is a view showing an example of the configuration of a pH adjusting device preferred in the present invention,

4 is a view showing another example of the configuration of a pH adjusting device preferred in the present invention, and

Fig. 5 is a diagram showing the configuration of the washing apparatus of the third embodiment of the present invention.

As a result of various studies to solve the above problems, the present inventors have focused on the redox potential of the cleaning liquid and studied how the redox potential of the liquid affects the surface potential. As a result, when the redox potential of the liquid is in the reducible region, even when the pH is neutral, the wafer surface and the surface potential of the fine particles can be negatively charged, and the knowledge that the reattachment of the fine particles due to electrical repulsion can be realized. The present invention was completed based on this knowledge. The present invention can contribute to a reduction in the amount of cleaning liquid and ultrapure water required for cleaning, and to prevent reattachment of fine particles, thereby providing a cleaning method and a cleaning apparatus for electronic component members that can be reliably washed even at a lower temperature than before. It is intended to be.

In addition, the present inventors have conducted various studies to solve the above problems. As a result, the present inventors have dissolved oxygen in ultrapure water to have a negative redox potential and at the same time use an acidic washing liquid whose pH is adjusted to less than 7 acid side. There is no fear of oxide film formation on the surface of the silicon wafer, and the knowledge that the surface roughness of the silicon wafer can be prevented is obtained, and the present invention has been completed based on this knowledge. An object of the present invention is to provide a cleaning method and a cleaning apparatus for electronic component members which can reliably clean the surface of electronic component members such as silicon wafers without causing an oxide film or surface roughness.

In addition, the present inventors have made various studies to solve the above problems. As a result, the present inventors can easily and reliably remove organic substances not only by washing with ultrapure water dissolved in ozone gas, but also by washing with alkaline washing liquid dissolved by ozone gas in ultrapure water. It discovered that there existed and came to complete this invention based on such knowledge. The present invention can contribute to a reduction in the amount of chemicals and ultrapure water required for cleaning, and a method and a cleaning apparatus for electronic component members which can reliably and easily remove organic substances on the surface of electronic component members even at low temperatures. The purpose is to provide.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning electronic component members such as electronic components or components of a manufacturing apparatus thereof, wherein the electronic component members are a cleaning liquid in which hydrogen gas is dissolved in ultrapure water, and cleaned with a cleaning liquid having a negative redox potential. It is characterized by.

Moreover, it is preferable that pHs of the washing | cleaning liquid which melt | dissolved the said hydrogen gas are 7 or more and less than 11. Thus, when hydrogen gas is melt | dissolved and the redox potential of a liquid is set to a reducing region, the surface potential of a wafer surface and microparticles | fine-particles can be charged negatively in pH range from neutral to alkaline region. Therefore, prevention of reattachment of fine particles by electrical repulsion can be realized. Therefore, the reattachment of the fine particles can be prevented, thereby contributing to the reduction of the amount of the cleaning liquid and the ultrapure water required for the cleaning, and the reattachment of the fine particles can be prevented to ensure reliable cleaning even at a lower temperature than conventionally.

Moreover, in the invention which makes the washing | cleaning liquid which melt | dissolved the said hydrogen gas acidic, it is preferable that pH is less than 7 and 3 or more. By dissolving hydrogen gas in ultrapure water, having a negative redox potential, and using an acidic cleaning liquid whose pH is adjusted to less than 7 acidic side, the formation of oxide film on the surface of the silicon wafer by dissolved oxygen can be suppressed. In addition, the surface roughness of the silicon wafer can be prevented. Therefore, the present invention can reliably clean the surface of electronic component members such as silicon wafers without causing oxide films or surface roughness.

Moreover, it is preferable that the said washing | cleaning liquid melts 0.05 ppm or more hydrogen gas.

In addition, the present invention relates to a method for cleaning electronic component members such as electronic components or components of a manufacturing apparatus thereof, wherein the electronic component members are used as a cleaning liquid in which ozone gas is dissolved in ultrapure water, and used in an alkaline cleaning liquid having a positive redox potential. By washing. Organic matter removal can be performed easily and reliably by washing | cleaning with the alkaline washing | cleaning liquid which dissolved ozone gas in ultrapure water. Therefore, it can contribute to the reduction of the use amount of chemical | medical agent and ultrapure water required for washing | cleaning, and the organic substance on the surface of electronic component members can be removed reliably and easily even at low temperature.

In addition, it is preferable that the alkaline cleaning liquid dissolve ozone gas of 0.05 ppm or more.

In addition, the pH of the washing liquid containing ozone is more than 7, characterized in that 11 or less.

In addition, it is preferable to use the ultrapure water degassed so that the dissolved oxygen concentration may be less than 10 ppm in the cleaning solution in which hydrogen gas or ozone is dissolved.

Moreover, it is preferable to perform washing | cleaning with the said cleaning liquid of the said electronic component members, irradiating an ultrasonic wave.

Moreover, it is preferable that the frequency of the ultrasonic wave to irradiate is 30 kHz or more.

In addition, when irradiating ultrasonic waves, it is preferable to dissolve the rare gas further in the cleaning liquid.

Moreover, it is preferable to wash by adjusting the temperature of the said washing | cleaning liquid to 20 degreeC-60 degreeC.

In addition, it is preferable to dissolve the hydrogen gas or ozone gas in ultrapure water through a gas permeable membrane.

Moreover, the washing | cleaning apparatus of the electronic component member which concerns on this invention is for implementing the said method.

According to the present invention as described above, the redox potential of the washing water of ultrapure water can be changed by dissolving the gas, and the washing effect can be enhanced by adjusting the pH to an appropriate pH according to the use. By degassing before gas dissolution, the property of the cleaning liquid can be made more appropriate. Moreover, cleaning can be performed more effectively by heating at the time of cleaning, irradiation of ultrasonic waves, and the like.

In the present invention, various components, materials, and the like used in the field of electronic component manufacturing and the like can be cited as examples of the electronic component members (cleaned objects) to be cleaned. For example, silicon substrates, group III-V semiconductor wafers, and the like. Such as semiconductor substrates, substrate materials such as liquid crystal glass substrates, finished products such as electronic components such as memory elements, CPUs, sensor elements, semi-finished products, components for electronic component manufacturing apparatus such as quartz reaction tubes, cleaning tanks, substrate carriers, etc. This is illustrated.

In the present invention, ultrapure water refers to crude water in raw water by treating raw water such as industrial water, tap water, well water, river water and lake water with a pretreatment device such as coagulation precipitation, filtration, coagulation filtration and activated carbon treatment. By removing the suspended solids, organic matters, etc., and then treating them with a primary pure water production apparatus mainly composed of desalination apparatuses such as ion exchangers and reverse osmosis membrane apparatuses. Most of the impurities are removed, and the first pure water is circulated to a secondary pure water production device comprising an ultraviolet irradiation device, a mixed phase polisher, and a membrane treatment device equipped with an ultrafiltration membrane or a reverse osmosis membrane. Refers to high purity pure water from which impurities such as fine particles, colloidal substances, organic matter, metal ions, and anions are removed as much as possible by treatment, and as the water quality thereof, for example, Resistivity is 17.0 MΩ · cm or more, total organic carbon is 100 µC / liter or less, the number of fine particles (particle diameter of 0.07 µm or more) is 50 / milliliter or less, the number of viable cells is 50 / milliliter or less, and the silica is 10 µgSiO ₂ / Liter or less, and sodium refers to 0.1 microgram Na / liter or less. In addition, in this invention, an ultrapure water manufacturing apparatus points out the combination of the said pretreatment apparatus, the primary pure water manufacturing apparatus, and the secondary pure water manufacturing apparatus.

In addition, a degassing apparatus such as a vacuum degassing apparatus or a membrane degassing apparatus using a gas permeable membrane may be added to the rear stage of the primary pure water manufacturing apparatus, and as raw water, a plant such as industrial water, tap water, well water, river water, lake water, etc. What mixed the various collection | recovery collect | recovered in the inside may be used.

(First embodiment)

1 shows an example of a cleaning device for electronic component members of the present invention, in which, reference numeral 1 denotes an ultrapure water producing system, 2 denotes a gas dissolving tank, 3 denotes a pH adjusting device, and 4 Represents a washing tank. The apparatus further includes a degassing apparatus 5 for removing the gas dissolved in the ultrapure water produced by the ultrapure water production system 1 and a to-be-cleaned object 6 which is cleaned in the cleaning tank 4 as necessary. An ultrasonic irradiation device 7 for irradiating ultrasonic waves is provided.

The ultrapure water production system 1 includes a pretreatment device, a primary pure water production device, and a secondary pure water production device. The pretreatment apparatus treats raw water in a coagulation precipitation apparatus, a sand filtration apparatus, and an activated carbon filtration apparatus. The primary pure water producing device treats this pretreated water with a reverse osmosis membrane device, a two-phase three tower ion exchange device, a mixed phase ion converter, and a precision filter to obtain primary pure water. The secondary pure water production apparatus performs ultraviolet irradiation, mixed phase polisher, and ultrafiltration membrane treatment on the primary pure water to remove fine particles, colloidal substances, organic matter, metal ions, and anions remaining in the primary pure water.

The ultrapure water produced by the ultrapure water production apparatus 1 preferably has the water quality shown in Table 1 below, and it is said that contaminants in the ultrapure water do not adhere to the wafer surface if the water is ultrapure water.

The ultrapure water produced by the ultrapure water production apparatus 1 is dissolved in the gas dissolving tank 2, but it is preferable to remove the gas dissolved in the ultrapure water by the degassing apparatus 5 before that. In this degassing apparatus 5, in particular, it is preferable to remove oxygen gas, nitrogen gas and carbon dioxide gas dissolved in ultrapure water, so that one or two or more kinds of dissolved gas concentrations are less than 10 ppm, preferably 2 ppm or less. It is preferable to degas. Moreover, when the dissolved gas concentration is 10 ppm or more, bubbles are generated during washing, bubbles adhere to the object to be cleaned, and the cleaning effect of the portion where bubbles are attached tends to decrease. In the degassing apparatus 5, as a method of degassing dissolved gas in ultrapure water, vacuum degassing through a gas permeable membrane is preferable.

In the degassing apparatus 5, hydrogen gas is dissolved in the gas dissolution tank 2 in ultrapure water degassing dissolved oxygen gas, nitrogen gas, carbon dioxide gas and the like. The cleaning solution obtained by dissolving hydrogen gas in ultrapure water in the gas dissolving tank 2 has a negative redox potential, but the dissolved hydrogen gas concentration in the cleaning solution is 0.05 ppm or more at 25 ° C and 1 atmosphere, particularly 0.8 to 1.6 ppm. It is preferable. In addition, when the dissolved hydrogen gas concentration is less than 0.05 ppm, it is often insufficient to bring the redox potential of the liquid to the reduction potential side, and as a result, the removal effect of the fine particles on the surface of the object to be cleaned is shown in Table 2 in Examples described later. Tends to decrease.

In other words, in the case of washing which wants to sufficiently remove the fine particles, it can be said that the pH of the washing liquid in which hydrogen gas is dissolved in ultrapure water is neutral to alkaline. In addition, it turns out that pH is fully obtained as a microparticle removal effect by adjusting to 8 or more.

As a method of dissolving hydrogen gas in ultrapure water, a method of injecting and dissolving hydrogen gas into ultrapure water through a gas permeable membrane, a method of bubbling and dissolving hydrogen gas in ultrapure water, a method of dissolving hydrogen gas through an ejector in ultrapure water, and a gas The hydrogen gas is supplied to the upstream of the pump which supplies ultrapure water to the dissolution tank 2, and the method of making it melt | dissolve by stirring in a pump, etc. are mentioned. As the hydrogen gas dissolved in the ultrapure water in the gas dissolving tank 2, it is preferable to use high purity hydrogen gas generated by electrolysis of the ultrapure water.

FIG. 2 shows an example of dissolving hydrogen gas obtained by electrolyzing ultrapure water in ultrapure water of the gas dissolution tank 2. In this example, hydrogen gas is injected into the ultrapure water through a gas permeable membrane and dissolved. In FIG. 2, reference numeral 8 denotes an ultrapure water electrolytic apparatus, and ultrapure water introduced from the ultrapure water supply pipe 9 into the ultrapure water electrolytic apparatus 8 is electrolyzed in the electrolytic apparatus 8, and the electrolytic apparatus 8 The high purity hydrogen gas produced in the cathode chamber of is sent to the gas melting tank 2 by the hydrogen gas supply pipe 10. The gas dissolving tank 2 is provided with a gas permeable membrane 11, and is supplied from the ultrapure water electrolytic apparatus 8 to the ultrapure water supplied from the ultrapure water supply pipe 12 to the gas dissolving tank 2 through the gas permeable membrane 11. Hydrogen gas is dissolved, and ultrapure water in which hydrogen gas is dissolved is sent from the supply pipe 13 to the pH adjusting device 3. In Fig. 2, reference numeral 14 denotes a drain valve for discharging ultrapure water after electrolysis, 15 denotes a pressure gauge for measuring hydrogen gas pressure in the gas dissolving tank 2 and 16 denotes a gas dissolving tank 2. An exhaust treatment apparatus for exhausting the supplied hydrogen gas, “17”, is a control valve for supply hydrogen gas amount control.

The washing | cleaning liquid which melt | dissolved hydrogen gas in the gas dissolution tank 2 adjusts pH in the pH adjuster 3. The pH of the washing liquid is preferably adjusted to 7 or more, more preferably 7 or more and less than 11, particularly preferably 8 to 10.

In order to adjust the pH of gas such as the alkali, but the use, such as aqueous ammonia, sodium hydroxide, potassium hydroxide, tetramethylammonium aluminum hydroxide (TMAH) aqueous alkali solution or ammonia gas, such as, the use of aqueous ammonia or ammonia gas, hydroxyl ions (OH ^- Since no metal ions or organic ions exist as counter ions and the counter ions are volatile, impurities are not attached to the object to be cleaned. Moreover, when pH is less than 7, as shown in Table 2 in the Example mentioned later, there exists a tendency for the removal effect of the microparticles | fine-particles on the surface to be cleaned to fall. Moreover, when pH becomes 11 or more, as shown in Table 2 and Table 3 of the Example mentioned later, there will be a tendency for the to-be-cleaned surface to become rough. In addition, as the pH adjuster 3, what is shown to FIG. 3, FIG. 4 can be employ | adopted.

Although the washing liquid whose pH was adjusted by the pH adjusting device 3 is sent to the washing tank 4, as described above, the washing liquid is preferably dissolved by dissolving hydrogen gas at 0.05 ppm or more, and the pH is preferably 7 or more. . For this reason, the redox potentiometer 18, the dissolved hydrogen concentration meter 19, and the hydrogen ion concentration meter 20 are provided in the middle of the washing | cleaning liquid supply pipe 22 which supplies a washing | cleaning liquid to the washing tank 4, and redox reduction in the washing liquid is carried out. It is preferable that the potential, dissolved hydrogen concentration and pH are always monitored to control the amount of hydrogen gas for dissolving ultrapure water in the gas dissolving tank 2 and the amount of alkali added in the pH adjusting device 3. These controls are performed by the controller 30. In addition, you may install the control apparatus 30 separately for every control object.

In the cleaning tank 4, the method of cleaning the object to be cleaned 6 with the cleaning liquid includes a batch cleaning method in which the object to be cleaned 6 is immersed in the cleaning liquid, and the object to be cleaned 6 while circulating the cleaning liquid. A circulating washing method for contacting and washing, a flow washing method for supplying the washing liquid from the bottom side of the washing tank 4 and washing while overflowing the upper portion of the washing tank 4, and spraying the washing liquid to the object to be cleaned 6 in a shower shape. And a method of cleaning by spraying a cleaning liquid onto the object to be cleaned 6 rotated at a high speed.

The heater 21 is provided in the washing tank 4, and the temperature of a washing liquid can be adjusted as needed. In order to obtain more excellent washing effect, it is preferable to wash the washing liquid by adjusting the temperature to 20 to 60 占 폚. Moreover, it is more effective to use ultrasonic irradiation together at the time of washing | cleaning. The ultrasonic wave generated by the ultrasonic irradiation device 7 preferably has a frequency of 30 kHz or more. In the case of irradiating ultrasonic waves, for example, in a batch cleaning method, a method such as irradiating the cleaning object 6 in the state of being immersed in the cleaning liquid supplied into the cleaning tank 4 is adopted. In the case of a method of cleaning by spraying from a nozzle or the like, a method of irradiating ultrasonic waves to the cleaning liquid at an upstream portion of the cleaning liquid spray nozzle is adopted.

When using ultrasonic irradiation together at the time of washing | cleaning, it is preferable to dissolve a rare gas further in a washing | cleaning liquid. Examples of the rare gas include helium, neon, argon, krypton, and xenon, or a mixture of two or more thereof. The rare gas is preferably dissolved in a cleaning solution of 0.05 ppm or more. The rare gas is preferably dissolved in ultrapure water in a process after degassing oxygen gas, nitrogen gas, carbon dioxide, etc. in the degassing apparatus 5, and the gas dissolving tank 2 for dissolving hydrogen gas in ultrapure water. It is preferable to carry out simultaneously or continuously with dissolution of hydrogen gas. As a method of dissolving the rare gas, the same method as that for dissolving hydrogen gas in ultrapure water can be adopted.

In addition, the washing apparatus of the present invention preferably has a gas seal structure in order to prevent gas components such as oxygen, nitrogen, carbon dioxide gas, etc. from the atmosphere into the ultrapure water or the washing liquid. In addition, in the above-mentioned example, although the hydrogen gas was melt | dissolved in ultrapure water in the gas dissolution tank 2, and pH adjustment was performed by the pH adjuster 3, although it showed, even if it is made to dissolve hydrogen gas after pH adjustment. good.

As described above, the wafer in which the fine particles on the surface are washed with a cleaning liquid having a negative redox potential by dissolving hydrogen gas in ultrapure water is rinsed with ultrapure water, and then, for example, the surface is removed by a metal removal step or the like.

[Specific Examples of First Example]

Hereinafter, a 1st Example is explained in more detail, giving a specific example.

Examples 1-1 to 1-8, Comparative Examples 1-1 to 1-3

After dipping a 6-inch silicon wafer (n-Si100) in a 0.5% dilute hydrofluoric acid solution for 10 minutes, rinsing with ultrapure water for 5 minutes by the overflow rinse method, and then continuing the average particle diameter of 10000 / ml 10 micrometers of aluminum particles were added to the ultrapure water and immersed in the adjusted contaminant for 10 minutes, followed by rinsing with ultrapure water for 5 minutes by the overflow rinse method, and dried as a spin-dry sample. Each of these 25 samples was washed under the conditions shown in Table 2 while irradiating ultrasonic waves at 950 kHz and 1200 W using the cleaning liquids shown in Table 2, followed by rinsing with ultrapure water for 5 minutes for spin drying.

In the cleaning liquid of Example 1-1, ultrapure water in which hydrogen gas was dissolved is used as pH fine-adjusted, and in the cleaning liquids of Examples 1-2 and 1-5 and Example 1-7, pH of ultrapure water in which hydrogen gas was dissolved was adjusted with ammonia. The cleaning liquid of Example 1-6 was used by adjusting the pH of the ultrapure water in which hydrogen gas and argon were dissolved with ammonia, and the ultrapure water in which carbon dioxide and hydrogen gas were dissolved in the cleaning liquid of Example 1-8. In addition, the cleaning solution of Comparative Example 1-1 uses only ultrapure water, and the cleaning solution of Comparative Example 1-2 is used by dissolving ammonia and hydrogen peroxide water in ultrapure water which does not dissolve hydrogen gas, and the cleaning solution of Comparative Example 1-3 is hydrogen. Hydrogen peroxide water was dissolved and used in ultrapure water which did not dissolve gas. Moreover, the washing tank capacity was 10 liters, and the overflow amount of the washing | cleaning liquid in the case of a batch type overflow system was 1 liter / min. Table 2 shows the number of aluminum particles adhering to the wafer surface after washing, the roughness of the wafer surface after washing, and the like before washing the wafer contaminated with aluminum particles.

In addition, the particle number of the wafer surface was measured with respect to the microparticles | fine-particles of 0.2 micrometer or more with the laser scattering type wafer surface-attached particle | grain inspection apparatus (made by TOPCON: WH-3), and showed the average value of 25 wafers.

In addition, the roughness of the wafer surface was measured by atomic force microscope (made by Seiko Electronics: AFM-SPI-3600),

○… Centerline Average Roughness (RMS) <5Å

×… Center line average roughness (RMS) 5Å or more

Evaluated.

Examples 1-9 to 1-13, Comparative Examples 1-4 to 1-6

The same silicon wafer as in the above example was washed with hydrofluoric acid solution, and then 25 samples adjusted by treatment with a contaminant solution containing aluminum particles were washed under the conditions shown in Table 3 using the cleaning solution shown in Table 3, respectively. Rinse with ultrapure water for 5 minutes and spin dry.

In the washing solution of Example 1-9, ultrapure water in which hydrogen gas was dissolved was used as it was pH-adjusted, and the washing liquid in Examples 1-10 to 1-13 was used by adjusting pH of ultrapure water in which hydrogen gas was dissolved with ammonia. In addition, the washing | cleaning liquid of Comparative Example 1-4, Comparative Example 1-5, and Comparative Example 1-6 used the same thing as the washing | cleaning liquid of the said Comparative Example 1-1, Comparative Example 1-2, and Comparative Example 1-3, respectively. The washing tank had the same capacity as in the above embodiment, and the overflow amount of the washing liquid in the case of the batch overflow system was also 1 liter / minute. In addition, in Examples 1-9 to 1131 and Comparative Examples 1-4 to 1-6, ultrasonic irradiation was not performed at the time of washing. Table 3 together shows the number of aluminum particles adhered to the wafer surface before and after washing contaminated with aluminum particles and the roughness of the aluminum surface after washing.

According to the cleaning method of the first embodiment, the cleaning effect equivalent to or higher than that of the conventional method can be obtained without using a large amount of the cleaning liquid as in the conventional method, so that such costs can be reduced for the raw materials and ultrapure water used in the cleaning liquid. Moreover, the cost for processing the used cleaning liquid etc. can also be reduced, and as a result, it can contribute to reduction of product cost compared with the case where the conventional washing | cleaning method is employ | adopted. In the cleaning method of the present invention, since the fine particles on the surface of the silicon wafer can be effectively removed even at a lower pH, compared to the conventional method of washing with ammonia / hydrogen peroxide mixed solution, a large amount of ammonia water is not consumed more than necessary as in the conventional method. The reduction in raw material cost can reduce the burden on the wastewater treatment apparatus from the original, and can reduce the wastewater treatment apparatus and reduce the treatment cost. In addition, since the treatment can be performed at a lower pH than the conventional method, it is not necessary to use hydrogen peroxide to prevent roughness of the surface of the silicon wafer by alkali, and it can contribute to the reduction of the raw material cost and the processing cost of drainage. Has

Second Embodiment

The overall configuration is as shown in FIG. 1 as in the first embodiment. In this second embodiment, the pH of the washing water is made acidic for the purpose of suppressing the formation of an oxide film during the rinsing after the chemical cleaning, and not roughening the surface of the object to be cleaned.

Hydrogen gas is dissolved in the gas dissolving tank 2 in the ultrapure water produced in the same manner as in the first embodiment in the ultrapure water producing apparatus 1. Ultrapure water is usually degassed at the time of manufacture, so the dissolved oxygen concentration in ultrapure water is very low, but dissolved oxygen is not completely removed. However, by dissolving hydrogen gas in ultrapure water, it is possible to remove the above-mentioned adverse effects due to dissolved oxygen by setting the redox potential of the liquid to a negative value, and the dissolved hydrogen concentration at 25 캜 and 1 atm is usually 0.05 ppm or more, In particular, it is preferable to dissolve hydrogen gas in the gas dissolution tank 2 so that it may become 0.8-1.6 ppm. If the dissolved hydrogen concentration is less than 0.05 ppm, the redox potential of the liquid may not be reliably negative. In addition, when the dissolved hydrogen concentration in ultrapure water is less than 0.05 ppm or when the removal of dissolved oxygen in the ultrapure water is insufficient, the ultrapure water remaining in the ultrapure water by the degassing apparatus 5 before the introduction into the gas dissolving tank 2 is performed. It is desirable to further remove dissolved oxygen.

In addition, in the ultrapure water production process, since nitrogen gas is normally sealed in the processing tank which performs various processes, ultrapure water has melt | dissolved nitrogen gas. Dissolved nitrogen in ultrapure water does not have to be removed because there is no risk of oxidizing or etching the surface of the silicon wafer. However, when ultrasonic waves are irradiated with nitrogen gas dissolved during cleaning, ammonium ions are generated to raise the pH of the liquid. There is a risk of making. For this reason, when irradiating ultrasonic waves at the time of washing | cleaning, it is preferable to process ultrapure water with the degassing apparatus 5, and also to remove dissolved nitrogen in ultrapure water.

In the degassing apparatus 5, it is preferable to remove the oxygen gas and the nitrogen gas, which are dissolved in the ultra lip, especially, so that the concentration of one or two or more of these dissolved gases is less than 10 ppm, preferably 2 ppm or less. It is preferable to gas. Further, when the dissolved gas concentration is 10 ppm or more, bubbles are generated during washing, bubbles adhere to the object to be cleaned, and the cleaning effect of the portion where bubbles are attached tends to decrease. This point is the same as in the first embodiment described above. In the degassing apparatus 5, as a method of degassing the dissolved gas in ultrapure water, vacuum degassing through the gas permeable membrane shown in FIG. 2 is preferable. However, other methods may be adopted.

In addition, the gas permeable membrane of the gas dissolving tank 2 or the degassing apparatus 5 is made of a lipophilic material such as silicon or a plurality of fine particles capable of permeating gas through a membrane made of a water repellent material such as fluorine resin. A hole is provided and the gas permeable but the water is not permeated. The gas permeable membrane can be used as a hollow fiber shaped structure, and when the gas permeable membrane is formed as a hollow fiber shaped structure, a method of permeating gas from the inner hollow side of the hollow yarn to the outside as a method of degassing or dissolving gas, Any method of allowing gas to pass through the inner cavity portion can be adopted.

As the gas dissolving tank 2, the structure shown in FIG. 2 is preferable.

After dissolving hydrogen gas in ultrapure water in the gas dissolving tank 2, the pH is adjusted by the pH adjusting device 3. In this second embodiment, the pH is less than 7, preferably the pH is less than 7, more than 3, Preferably it adjusts to the range of 4-6. In this manner, by adjusting the pH of the ultrapure water dissolved in hydrogen gas to acidic, it is possible to prevent the formation of an oxide film on the surface of the object to be cleaned, and to prevent the surface from being roughened. Therefore, it is preferable to use acidic hydrogen gas dissolved ultrapure water in the cleaning of such use.

Therefore, in order to adjust pH, the method of melt | dissolving acid or acidic gas in the ultrapure water which melt | dissolved hydrogen gas is employ | adopted. As the acid, for example, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid and the like are used. For example, carbon dioxide gas is used as the acidic gas, but a method of dissolving the carbon dioxide gas and adjusting the pH is preferable because of less influence by coexisting ions. . When acid is used for pH adjustment, the pH adjuster 3 can be comprised by the storage tank 23 and the pump 24 which store an acid, for example, as shown in FIG. The method of adding and mixing acid in the middle of the piping for supplying the liquid to the washing tank 4 is adopted. 3, reference numeral 25 denotes a control valve for adjusting the supply amount of acid.

In addition, when acidic gas, such as carbon dioxide, is added for pH adjustment, as shown in FIG. 4, the pH adjusting apparatus 3, for example, the gas supply apparatus 26 and the gas dissolving tank 27 which supply an acidic gas, for example. It can be configured as. As this gas dissolution tank 27, the same structure as the gas dissolution tank 2 for dissolving the said hydrogen gas can be used.

The acidic washing liquid whose pH is adjusted by the pH adjusting device 3 is sent to the washing tank 4, but as described above, the washing liquid must have a pH of less than 7 and has a negative redox potential by dissolving hydrogen gas. Do. For this reason, the redox potentiometer 18, the dissolved hydrogen concentration meter 19, and the hydrogen ion concentration meter 20 are provided in the middle of the washing | cleaning liquid supply pipe 22 which supplies a washing | cleaning liquid to the washing tank 4, and redox in a washing | cleaning liquid is carried out. It is preferable that the potential, dissolved hydrogen concentration and pH are always monitored and the amount of hydrogen gas dissolved in ultrapure water in the gas dissolving tank 2 and the amount of acid or acid gas added in the pH adjusting device 3 can be controlled. Do. This control is performed by the controller 30.

In the cleaning tank 4, the cleaning solution 6 is cleaned with an acidic cleaning solution in the same manner as in the first embodiment described above, and the cleaning solution is showered in the batch cleaning method, the circulation cleaning method, the flow cleaning method, and the object to be cleaned 6. Examples thereof include a method of spraying and washing in a shape, a method of spraying and washing a cleaning liquid on the object to be cleaned 6 rotated at high speed.

In addition, the structure and operation | movement of the heater 21 and the ultrasonic irradiation apparatus 7 are the same as that of 1st Embodiment mentioned above. In addition, dissolution of the rare gas, gas seal of the washing apparatus, the position of pH adjustment, and the like are the same as those in the first embodiment.

[Specific Example of Example 2]

Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples.

Example 2-1

The surface of the wafer was treated by RCA cleaning by immersing a 6-inch silicon wafer substrate (n + Si100) in which 0.5% dilute hydrofluoric acid was removed for 10 minutes. Subsequently, this wafer was washed with the cleaning liquid of the composition shown in Table 4 using the washing | cleaning apparatus shown in FIG. 1, and then spin-dried. In addition, pH adjustment of the washing | cleaning liquid was performed using hydrochloric acid using the pH adjuster shown in FIG. Table 4 shows the results of measuring the oxide film thickness and the surface roughness of the wafer surface before and after the treatment with the cleaning liquid.

The value of the oxide film thickness of the wafer surface of the said Table 4 measured the 25 wafers using the optoelectronic X-ray analyzer (ESCA-200 made from Seiko Electronics Co., Ltd.), and showed the average value.

In addition, the value of the roughness of the wafer surface was measured about 25 wafers using the atomic force microscope (SPI-3600 made from Seiko Electronics Co., Ltd.), and showed the average value.

Comparative Example 2-1

The same treatment as in Example 3-1 was carried out except that the ultrapure water shown in Table 4 was used instead of the acidic washing liquid. Table 4 shows the results of measuring oxide film thickness and surface roughness of the wafer surface before and after the treatment with ultrapure water.

Example 2-2

The wafer surface was treated by immersing a 6-inch silicon wafer substrate (n + Si100) in 0.5% dilute hydrofluoric acid for 10 minutes by performing RCA cleaning to remove surface impurities. Subsequently, this wafer was washed with the cleaning liquid of the composition shown in the said Table 4 using the washing | cleaning apparatus shown in FIG. 1, and then spin-dried. In addition, pH adjustment of the washing | cleaning liquid was performed with carbon dioxide using the pH adjuster shown in FIG. The result of having measured the oxide film thickness and surface roughness of the wafer surface before and after a process with a washing | cleaning liquid was shown in Table 4 together.

According to the cleaning method of the second embodiment of the present invention, in the process of cleaning electronic component members such as silicon wafers, the surface of the electronic component members is roughened or thicker than the conventional method of cleaning the wafer surface with ultrapure water. There is no fear of forming an oxide film, and there is an effect that the surface of the electronic component members can be easily cleaned to a completely clean surface.

Third Embodiment

The overall configuration of the third embodiment is as shown in FIG. 5, but is basically the same as that of the first and second embodiments described above. In the third embodiment, ozone gas is dissolved in the gas melting tank 2. In the pH adjusting device 3, the washing water is adjusted to be alkaline. In addition, the dissolved ozone concentration meter 31 is replaced with the dissolved hydrogen concentration meter 19.

In the ultrapure water produced by the ultrapure water producing system 1, ozone gas is dissolved in the gas dissolving tank 2. By dissolving ozone gas in ultrapure water, it is possible to obtain a cleaning liquid having a redox potential of an amount most suitable for removing organic matters on the surface of a wafer or the like, but the dissolved ozone concentration at 25 ° C and 1 atm is usually 0.05 ppm or more, in particular 1 ppm. It is preferable to dissolve ozone gas in the gas dissolving tank 2 so that it may become -10 ppm. The ultrapure water supplied to the gas dissolving tank 2 is usually degassed at the time of manufacture, so the concentration of dissolved gas in the ultrapure water is very low, but nitrogen and carbon dioxide react with ozone to be ionized or dissociate in water. Since ionization lowers resistivity, it is preferable to further remove dissolved nitrogen and dissolved carbon dioxide remaining in the ultrapure water by the degassing apparatus 5 before introducing the ultrapure water to the gas dissolving tank 2.

In the degassing apparatus 5, it is preferable to degas so that all dissolved gas concentrations in the ultrapure water supplied to the gas dissolving tank 2 are less than 10 ppm, preferably 2 ppm or less. In addition, when the dissolved gas concentration is 10 ppm or more, bubbles are generated at the time of washing, bubbles adhere to the object to be cleaned, and the cleaning effect of the portion where bubbles are attached tends to decrease. In the degassing apparatus 5, as a method of degassing dissolved gas in ultrapure water, vacuum degassing through a gas permeable membrane is preferable.

As a method of dissolving ozone gas in ultrapure water, a method of injecting and dissolving ozone gas into ultrapure water through a gas permeable membrane, a method of bubbling and dissolving ozone gas in ultrapure water, a method of dissolving ozone gas through an ejector in ultrapure water, and a gas The method etc. which supply ozone gas to the upstream of the pump which supplies ultrapure water to the dissolution tank 2, and dissolve by stirring in a pump are mentioned. The ozone gas dissolved in the ultrapure water in the gas dissolving tank 2 is preferable because the ozone gas generated by reducing the hydroxide ions in the ultrapure water by electrolysis of the ultrapure water is of high purity.

The gas permeable membrane of the gas dissolving tank 2 or the degassing apparatus 5 can pass gas through a membrane made of a lipophilic material such as silicon or a water repellent material such as a fluorine-based resin as in the case described above. What is provided is a structure in which a plurality of micropores are provided to allow gas to pass but not to permeate water. The gas permeable membrane can be used as a hollow fiber-shaped structure, and when the gas permeable membrane is formed as a hollow fiber-shaped structure, a method of permeating gas from the inner hollow side of the hollow yarn to the outside as a method of degassing or dissolving gas, and the outer side of the hollow yarn In the method, any one of the methods of permeating gas to the inner cavity side may be adopted.

The gas dissolving tank 2 has the same configuration as that for dissolving hydrogen gas, but dissolves ozone gas in place of hydrogen gas. That is, in the gas dissolving tank 2, ozone gas is dissolved through the gas permeable membrane 11 in the ultrapure water supplied from the ultrapure water supply pipe 12 to the gas dissolving tank 2, and the ultrapure water in which the ozone gas is dissolved has a pH in the supply pipe 13. It is sent to the adjusting device 3. That is, ozone gas is supplied to the gas dissolution tank 2 from the hydrogen gas supply pipe 10 of a figure.

After dissolving ozone gas in ultrapure water in the gas dissolving tank 2, it adjusts to alkalinity in the pH adjuster 3. In the cleaning method of the present invention, ozone in an alkaline cleaning solution is decomposed and organic matter on the surface such as a silicon wafer is removed by the decomposed ozone. The higher the pH of the cleaning solution, the higher the decomposition rate of ozone, and thus the organic material per unit time. The removal effect of is improved, but if the pH is too high, the removal effect of organic matter is lost in a short time. For this reason, the washing liquid preferably has a pH of 11 or less, and more preferably adjusts the pH to a range of 9 to 11, particularly preferably 10 to 10.5. In addition, it is preferable to make the ultrapure water which melt | dissolved ozone gas alkaline for the said reason just before performing washing | cleaning.

In order to adjust pH, the method of melt | dissolving liquid or gaseous alkali in ultrapure water which dissolved ozone gas is employ | adopted. As alkali, aqueous ammonia solution and ammonia gas are preferable. When liquid alkali is used for pH adjustment, the pH adjuster 3 can be comprised by the storage tank 23 and the pump 24 which store alkali, for example, as shown in FIG. The method of adding and mixing a liquid alkali in the middle of the piping which supplies liquid to the washing tank 4 is employ | adopted. 3, reference numeral 25 denotes a control valve for adjusting the supply amount of alkali.

In addition, when adding gaseous alkali for pH adjustment, as shown in FIG. 4, the pH adjustment apparatus 3 is comprised by the gas supply apparatus 26 and the gas dissolution tank 27 which supply alkaline gas, for example. can do. As this gas dissolving tank 27, the thing of the structure provided with the gas permeable membrane 11 like the gas dissolving tank 2 for dissolving the said ozone gas can be used.

The alkaline washing liquid whose pH is adjusted by the pH adjusting device 3 is sent to the washing tank 4, but as described above, the washing liquid is alkaline, and it is necessary to dissolve ozone gas and have a positive redox potential. For this reason, the redox potential 18, the dissolved ozone concentration meter 31, and the hydrogen ion concentration meter 20 are provided in the middle of the washing | cleaning liquid supply pipe 22 which supplies a washing | cleaning liquid to the washing tank 4, and the redox potential in a washing | cleaning liquid is provided. It is preferable to configure so that the dissolved ozone concentration and pH are always monitored and the amount of ozone gas dissolved in ultrapure water in the gas dissolving tank 2 and the amount of alkali added in the pH adjusting device 3 can be controlled. The controller 30 of FIG. 1 controls the amount of ozone gas dissolved and the amount of alkali added.

Incidentally, the constituent action of the heater 21 and the ultrasonic irradiation device 7 or the dissolution of the rare gas, the gas seal of the cleaning device, the position of pH adjustment, and the like are the same as in the first and second embodiments described above.

[Specific Example of Example 3]

Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples.

Examples 3-1 to 3-6, Comparative Examples 3-1 to 3-3

RCA cleaning of 6-inch silicon wafer substrate (n + Si100) to remove impurities on the surface, immersed in 0.5% dilute hydrofluoric acid for 10 minutes, then rinsed with ultrapure water for 5 minutes by overflow rinse method, and sulfuric acid at 130 Hydrogen peroxide (a mixture of volume ratio 98% sulfuric acid: 30% hydrogen peroxide = 4: 1) was washed. After rinsing and drying the silicon wafer with ultrapure water, the commercially available polyethylene wrap film is brought into close contact with the wafer surface to prevent bubbles from entering and left in the clean room for one day to transfer the organic matter attached to the polyethylene wrap film surface to the silicon wafer surface. I was. After peeling off the polyethylene wrap film in close contact with the silicon wafer and measuring the surface contact angle due to the drop of ultrapure water droplets as an indicator of the degree of adhesion of organic matter to the silicon wafer surface, the wafer was washed and dried under the cleaning solution and conditions shown in Table 5 below. Then, the contact angle of the surface was measured once again to investigate the removal effect of the organic matter. The results are shown in Table 5 together. In addition, the surface contact angle of the silicon wafer before contacting and contaminating with a polyethylene wrap film was 21 degrees (average value of 25 wafers).

Comparative Example 3-4

The washing was carried out in the same manner as in Examples 3-1 to 3-6 and Comparative Examples 3-1 to 3-3, except that 5 ppm of ozone dissolved in ultrapure water was used as the washing liquid. Table 5 shows the results of measuring the contact angle of the wafer surface before and after cleaning.

Comparative Example 3-5

Examples 3-1 to 3-6 and Comparative Examples, except that the solution was washed at 130 ° C. using sulfuric acid hydrogen peroxide solution (a mixture of volume ratio 98% sulfuric acid: 30% hydrogen peroxide = 4: 1) as the washing liquid. Cleaning was carried out in the same manner as in 3-1 to 3-3. The result of having measured the contact angle of the wafer surface before and behind washing | cleaning is shown in Table 5 together.

Examples 3-7 to 3-12, Comparative Examples 3-6 to 3-8

After performing RCA cleaning, dilute hydrofluoric acid washing and rinsing with ultrapure water in the same manner as in Examples 3-1 to 3-6, the contact angle of the surface of the silicon wafer contaminated with organic matter by closely contacting the polyethylene lab film on the surface was measured. , 950 kHz, and 1200 watts were irradiated with the washing solution and conditions shown in Table 6 while irradiating with ultrasonic waves, and then dried, and the contact angle of the surface was measured again. The results are shown in Table 6 together.

Comparative Example 3-9

The washing was carried out in the same manner as in Examples 3-1 to 3-6 and Comparative Examples 3-1 to 3-3, except that 5 ppm of ozone dissolved in ultrapure water was used as the washing liquid. The result of having measured the contact angle of the wafer surface before and behind washing | cleaning is shown together in the said Table 6.

Comparative Example 3-10

Examples 3-1 to 3-6 and Comparative Examples, except that the solution was washed at 130 ° C. using sulfuric acid hydrogen peroxide solution (a mixture of volume ratio 98% sulfuric acid: 30% hydrogen peroxide = 4: 1) as the washing liquid. Cleaning was carried out in the same manner as in 3-1 to 3-3. The result of having measured the contact angle of the wafer surface before and behind washing | cleaning is shown together in the said Table 6.

According to the method of the third embodiment, in the cleaning process of electronic component members such as silicon wafers, the surface is more reliably surfaced in a shorter time than the conventional method of cleaning organic substances with ultra pure water only by washing with hydrogen peroxide or by dissolving ozone gas. Organics can be removed. In addition, according to the method of the present invention, the amount of chemicals used for cleaning and ultrapure water used for rinsing after washing can be reduced, and the cost of chemicals and ultrapure water can be reduced, and the cost of waste liquid treatment after use can be reduced. Furthermore, the manufacturing cost of electronic component members can be reduced, and the like.

It is used for the washing | cleaning process of electronic component members, such as a silicon wafer.

Claims (27)

In the cleaning method of electronic component members, such as an electronic component or the component of the manufacturing apparatus of this, A cleaning method in which electronic component members are dissolved in ultrapure water by a cleaning liquid having a negative redox potential. The method of claim 1, PH of the said cleaning liquid is 7 or more and less than 11, The cleaning method of the components of electronic components characterized by the above-mentioned. The method of claim 1, PH of the said washing | cleaning liquid is less than seven, and the washing | cleaning method of electronic component members characterized by the above-mentioned. The method according to any one of claims 1 to 3, A cleaning method for electronic component members, wherein the cleaning solution dissolves hydrogen gas of 0.05 ppm or more. The method according to any one of claims 1 to 3, The cleaning solution is a cleaning method for electronic component members, characterized in that the ultra-pure water degassed so that the dissolved oxygen concentration is less than 10ppm. The method according to any one of claims 1 to 3, A cleaning method for electronic component members, wherein cleaning with the cleaning liquid of the electronic component members is performed while irradiating ultrasonic waves. The method of claim 6, And said frequency of said ultrasonic wave is 30 kHz or more. The method of claim 6, The cleaning method is characterized in that the cleaning solution is further dissolved in a rare gas. The method according to any one of claims 1 to 3, A cleaning method for electronic component members, wherein the temperature of the cleaning liquid is adjusted to 20 ° C to 60 ° C for cleaning. The method according to any one of claims 1 to 3, The hydrogen gas is dissolved in ultrapure water through a gas permeable membrane. Ultrapure water production apparatus for producing ultrapure water; Gas dissolving unit for dissolving hydrogen gas in the ultra-pure water prepared above; And And a cleaning unit for cleaning the electronic component members with a cleaning liquid having a negative redox potential generated by dissolving hydrogen gas in ultrapure water in the gas dissolving unit. The method of claim 11, And a pH adjusting device for adjusting the pH of the cleaning liquid. The method of claim 12, A dissolved hydrogen concentration detecting device for detecting the dissolved hydrogen concentration in the washing water; And And a gas dissolution controller for controlling dissolution of hydrogen gas by the gas dissolving device based on the detected concentration of hydrogen hydrogen. The method of claim 12, A pH detecting device for detecting pH in the washing water; And a pH control device for controlling pH adjustment by the pH adjusting device based on the detected pH. The method according to any one of claims 11 to 14, And an ultrasonic irradiation device for irradiating ultrasonic waves to the washing water of the washing unit. In the cleaning method of electronic component members, such as an electronic component or the component of the manufacturing apparatus of this, A cleaning method in which electronic component members are dissolved in ultrapure water using an alkaline cleaning liquid having a positive redox potential. The method of claim 16, The alkaline cleaning solution dissolves ozone gas of 0.05 ppm or more. The method of claim 16, The pH of the said cleaning liquid exceeds 7 and is 11 or less, The cleaning method of the electronic component members characterized by the above-mentioned. The method according to any one of claims 16 to 18, The cleaning solution is a cleaning method for electronic component members, characterized in that the ultra-pure water degassed so that the dissolved oxygen concentration is less than 10ppm. The method according to any one of claims 16 to 18, A cleaning method for electronic component members, wherein cleaning with the cleaning liquid of the electronic component members is performed while irradiating ultrasonic waves. The method of claim 20, And said frequency of said ultrasonic wave is 30 kHz or more. The method according to any one of claims 16 to 18, A cleaning method for electronic component members, wherein the temperature of the cleaning liquid is adjusted to 20 ° C to 60 ° C for cleaning. The method according to any one of claims 16 to 18, The ozone gas is dissolved in ultrapure water through a gas permeable membrane. Ultrapure water production apparatus for producing ultrapure water; Gas dissolving unit for dissolving ozone gas in the ultra-pure water prepared above; PH adjusting unit for adjusting the pH of the liquid produced by dissolving ozone gas in ultrapure water in the gas dissolving unit; And And a cleaning unit for cleaning the electronic component members with an alkaline cleaning liquid having a positively adjusted redox potential by dissolving the ozone gas. The method of claim 24, A dissolved ozone concentration detecting device for detecting the dissolved ozone concentration in the washing water; And And a gas dissolution control device for controlling dissolution of hydrogen ozone by the gas dissolving device based on the detected dissolved ozone concentration. The method of claim 24, A pH detecting device for detecting pH in the washing water; And And a pH control device for controlling pH adjustment by the pH adjusting device based on the detected pH. The method according to any one of claims 24 to 26, And an ultrasonic irradiation device for irradiating ultrasonic waves to the washing water of the washing unit.