WO2007108481A1

WO2007108481A1 - Substrate cleaning method and substrate cleaning apparatus

Info

Publication number: WO2007108481A1
Application number: PCT/JP2007/055724
Authority: WO
Inventors: Eiji Matsumura; Nobuko Hagiwara
Original assignee: Eiji Matsumura; Nobuko Hagiwara
Priority date: 2006-03-20
Filing date: 2007-03-20
Publication date: 2007-09-27
Also published as: JP2008153605A; TW200802575A; JP2011066389A

Abstract

[PROBLEMS] To provide a substrate cleaning method wherein substrate is not adversely affected. [MEANS FOR SOLVING PROBLEMS] A substrate cleaning method is provided for cleaning a substrate by using ozone water produced by a gas-liquid mixing method without using additives. The method is characterized in that the diameter (R) of ozone bubbles contained in the ozone water is 0<R≤50nm. Since the diameter of the ozone bubble is within such range, buoyancy is not easily given from the ozone water. As a result, the ozone bubbles are prevented from moving up, and the ozone water is not easily degassed. Thus, sufficient cleaning effects are obtained by having the ozone water not easily degassed.

Description

Substrate cleaning method and substrate cleaning apparatus

Technical field

The present invention relates to a substrate cleaning method and a substrate cleaning apparatus for cleaning a substrate such as a semiconductor substrate such as a semiconductor wafer, a glass substrate, an electronic circuit module, and a liquid crystal display using ozone water. .

Background art

[0002] Patent Document 1 discloses a technique for generating ozone water used for cleaning a semiconductor substrate by mixing ozone (ozone gas) generated by an ozone generator into water to be treated via an ejector (hereinafter referred to as “ 1st prior art "). Further, Patent Document 2 discloses a method of cleaning a semiconductor substrate using ozone water supplemented with an organic solvent such as ethanol or isopropyl alcohol (hereinafter referred to as “second prior art” as appropriate). The organic solvent is added to extend the ozone half-life in ozone water, which is said to be 2 to 5 minutes when stored in a container with a large opening such as a washing tank. On the other hand, the third prior art requires the adjustment of the amount of addition to prevent the addition of organic solvent more than necessary because it causes deterioration of the substrate quality due to residual carbon components. Patent Document 3 describes a technique for removing a photoresist film from pure ozone-containing water under conditions including a temperature of approximately 22 ° C to 45 ° C and a dissolved ozone concentration of approximately 30 ppm or more (hereinafter referred to as “ 3rd prior art ”). Ozone-containing pure water diffuses ozone through a porous tube with micropores of about 1 μm in ultrapure water. Further, the above temperature condition according to the third prior art is realized by a method of dissolving ozone in heated pure water. On the other hand, in Patent Document 4, an electrolyte containing iron bubbles, manganese, calcium, sodium, magnesium ions and other mineral ions is mixed in an aqueous solution containing ozone bubbles having a diameter of 10 to 50 m, and the mixed aqueous solution is submerged in water. It is described that nanobubbles of 50 to 500 nm can be obtained by discharging. The aqueous solution containing the nanobubbles is referred to below as “conventional ozone water” and the conventional ozone water generation technique is referred to as “fourth conventional technique” as appropriate. Patent Document 1: Japanese Patent Laid-Open No. 2006-49453 (see paragraph 0034)

Patent Document 2: JP 2004-79649 A (see paragraphs 0011 and 0018)

Patent Document 3: Japanese Patent Laid-Open No. 2002-33300 (see paragraphs 0011, 0018, 0019, 0022) Patent Document 4: Japanese Patent Laid-Open No. 2005-246293 (see paragraphs 0016-0025, FIG. 1) Disclosure of the Invention

Problems to be solved by the invention

By the way, according to experiments conducted by the inventors of the present application, the ozone solubility of the generated ozone water cannot be sufficiently increased only by using the ejector. For this reason, a large amount of ozone is degassed, and the desired cleaning effect cannot be obtained. The main reason why the ozone solubility cannot be increased is that the dissolved ozone bubbles have a particle size of approximately 1 m (micrometer mouth meter) or more, so the ozone bubbles receive buoyancy from the ozone water and rise to the water surface. In the point. In order to make it difficult for the ozone bubbles to rise to the surface of the water, the particle size of the dissolved ozone bubbles should be suppressed to approximately 500 nm or less. However, the first to third prior arts described above do not realize ozone water that includes only ozone bubbles having a particle size of 500 nm or less. The fourth technique described above is a force that seems to provide ozone water containing ozone bubbles with a particle size of 50-500. This requires electrolyte contamination. Ozone water mixed with electrolytes (additives) such as iron, mangan, calcium, sodium, magnesium ions, and other mineral ions may adversely affect the semiconductor substrate. Suitable for cleaning! Needless to say, an organic solvent needs to be mixed into the ozone water provided by the second prior art, and such an organic solvent is not suitable for cleaning a semiconductor substrate. In this regard, the third prior art requires a solution to the adjustment of the amount of organic solvent added, but it is natural that the organic solvent should not be included as long as it is an additive. In the third prior art 3, ozone diffusion is performed through 3 micropores of about 1 μm, so the particle size of ozone bubbles contained in ozone-containing pure water is almost: L m It will never be smaller. Therefore, even with the third technology, it is not possible to realize ozone water containing only ozone bubbles having a particle size of 1000 nm (l μm) or less. The problems to be solved by the present invention are a substrate cleaning method and a substrate which do not adversely affect the substrate and can obtain a sufficient cleaning effect by not easily degassing. It is to provide a cleaning device.

Means for solving the problem

[0004] The inventors who have conducted extensive research to solve the above problems were able to obtain ozone water containing ozone bubbles with a diameter of 50 nm or less when ozone was mixed with water to generate ozone water. . This ozone water does not contain or contain additives such as electrolytes or organic solvents. The ozone water is significantly different from the conventional ozone water described in the background section in that it does not contain additives. The present invention intends to clean the substrate using the ozone water. The detailed configuration of the invention will be described again. It should be noted that the definitions of terms used to describe an invention described in any claim are the inventions described in other claims as long as they are possible in terms of their nature regardless of the category of the invention or before and after the description. Shall also apply.

[0005] (Characteristics of the invention described in claim 1)

The substrate cleaning method according to the invention of claim 1 (hereinafter referred to as “the cleaning method of claim 1” as appropriate) is a substrate cleaning method of cleaning a substrate using ozone water that is added and generated by a gas-liquid mixing method. is there. Here, the particle size R of the ozone bubbles contained in the ozone water is 0 <R≤50ηm. According to the experiments conducted by the inventors, the particle size R is almost 30 nm or less. Depending on the various conditions during gas-liquid mixing, the presence of ozone bubbles exceeding 30 nm and 50 nm or less Was also confirmed. Since ozone water is produced by a gas-liquid mixing method in which ozone is mixed with water, ozone bubbles with a particle size exceeding 50 nm are also present in addition to ozone bubbles with a particle size of 50 nm or less (for example, less than 1% of the total amount). (Although only a few) It cannot be completely denied that it may be contained accidentally, but even in such a case, ozone bubbles with a particle size exceeding 50 nm should have a large particle size. In addition, the amount of contribution to cleaning is extremely low, if any, because it is extremely small compared to the total amount of ozone water. Therefore, the ozone water in the part containing ozone bubbles having a particle size of more than 50 nm is not covered by the ozone water according to the present invention. That is, the ozone water used for substrate cleaning in the above case includes ozone bubbles having a particle size of 50 nm or less according to the present invention and ozone water according to the present invention and ozone bubbles having a particle size of more than 50 nm. It should be construed that the ozone water is simply mixed. In addition, ozone water Examples of the substrate cleaning method used include a method of immersing the substrate in ozone water, or spraying or bathing the substrate with ozone water. As long as it does not impair the properties of the additive-free ozone water, it does not prevent the use of ozone or water cleaning with light or ultrasonic irradiation as described later. If there is a cleaning process other than ozone water cleaning before and after ozone water cleaning (for example, the substrate surface is made hydrophilic by irradiating excimer light in advance to promote ozone cleaning). Such a cleaning process and the like are included in the technical idea of the present invention.

[0006] According to the cleaning method of claim 1, the contained ozone is not easily degassed from the ozone water, so that the cleaning effect of the substrate can be reliably maintained for a long time. It is also a force that effectively suppresses ozone degassing. In other words, by suppressing the particle size to 50 nm or less, the buoyancy that the ozone bubbles are subjected to the ozone hydropower is extremely small, so the ozone bubbles do not easily rise to the water surface. In other words, it stays stably in ozone water. Ozone bubbles that stay stably are very rarely degassed by impact when ozone water collides with the substrate. These realize effective suppression of ozone deaeration. Furthermore, since the particle size is extremely small, irregularities having a nanometer (nm) level dimension (for example, 60 nm) are often formed on the surface of the substrate and the formed material on the substrate. In order for ozone to react in the recess, ozone bubbles must be able to enter the recess. However, the ozone water according to the present invention enables such ozone reaction. In addition, since cleaning is performed using ozone water with no additive, there is no possibility of adversely affecting the substrate due to the addition of additives. In addition, since no additive is mixed, the ozone water after washing does not adversely affect the environment caused by the additive. Furthermore, since ozone degassing is effectively suppressed, ozone does not degas or is very difficult to degas. In other words, if ozone is inhaled by humans, harmful substances will not come out of the ozone water.

[0007] (Characteristics of the invention described in claim 2)

The substrate cleaning method according to the invention described in claim 2 (hereinafter referred to as “cleaning method of claim 2” t 適宜) is performed by adding ozone water in which the particle size R of the contained ozone bubbles is 0 <R ≦ 50 nm. V, an ozone water generation process generated by a gas-liquid mixing method, and an ozone water cleaning process for cleaning the substrate using the ozone water generated by V in the ozone water generation process. It is. The nature of the ozone water generated in the ozone water generation process and the type of cleaning method used in the ozone water cleaning process are not different from those described in the description of the cleaning method in claim 1.

[0008] According to the cleaning method of claim 2, since the contained ozone does not easily deaerate from the ozone water, the cleaning effect of the substrate can be reliably maintained for a long time. It is also a force that effectively suppresses ozone degassing. In other words, by suppressing the particle size to 50 nm or less, the buoyancy that the ozone bubbles are subjected to the ozone hydropower is extremely small, so the ozone bubbles do not easily rise to the water surface. This achieves effective suppression of 1S ozone deaeration. Furthermore, since the particle size is extremely small, concaves and convexes with a nanometer (nm) level dimension (for example, 60 nm) are often formed on the surface of the substrate or on the surface of the substrate formation. In order to react ozone in the recess, ozone bubbles must be able to enter the recess. However, according to the ozone water according to the present invention, such ozone reaction is possible. Moreover, since cleaning is performed using additive-free ozone water, there is no possibility of adversely affecting the substrate due to mixing of additives. In addition, since no additive is mixed, the ozone water after washing does not adversely affect the environment caused by the additive. Furthermore, since ozone degassing is effectively suppressed, ozone does not degas or is extremely difficult to degas. In other words, the harmful effect of ozone does not come out of the ozone water!

[0009] (Characteristics of the invention described in claim 3)

In the substrate cleaning method according to the invention of claim 3 (hereinafter referred to as “cleaning method of claim 3” as appropriate), as a preferred embodiment of the cleaning method of claim 1 or 2, it is used in the gas-liquid mixing method. Pure water or ultrapure water is used as raw water.

[0010] According to the cleaning method of claim 3, on the premise of the operational effect of the cleaning method of claim 1 or 2, the use of pure water or ultrapure water increases the purity of ozone water. This can further eliminate the risk of adverse effects. That is, when water other than pure water or ultrapure water (for example, well water or tap water) is used as raw water for generating ozone water, there is a possibility that foreign substances are originally present in the raw water. A certain force If pure water or ultrapure water is used, even such foreign substances will be mixed in as long as the purity of the pure water or ultrapure water is reached. This is the reason why the risk of adverse effects on the substrate can be further eliminated. Na Oh. The water obtained by filtering the tap water and well water in the above example using a reverse osmosis membrane, for example, corresponds to the pure water or the like.

[0011] (Characteristics of the invention according to claim 4)

In the substrate cleaning method according to the invention of claim 4 (hereinafter referred to as “the cleaning method of claim 4” as appropriate), as a preferred embodiment of the cleaning method of claim 2 or 3, in the ozone water generating step, a small diameter is used. The raw water is passed through a bench lily pipe having a channel, ozone is supplied to the bench lily pipe, and a magnetic force is applied to at least a small path of the bench lily pipe. The bench lily tube is sometimes called an ejector.

[0012] According to the cleaning method of claim 4, on the premise of the operational effect of the cleaning method of claim 2 or 3, it is possible to cause a magnetic force to act on at least a small path of a bench lily tube supplying ozone. Ozone water generation with bubble size R 0 <R ≤ 50 nm is extremely easy. The pressure of the raw water passing through the venturi pipe increases at a stroke as it approaches the small path, and decreases at a stroke after passing through the small path. When the pressure decreases, the inside of the bench lily tube is in a vacuum or a negative pressure state close to vacuum, and ozone supplied by this negative pressure state is sucked into the raw water. The suctioned ozone is intricately intertwined with the above pressure change and the change in the flow of raw water (ozone water) as it passes through a small path, and is stirred and mixed at once. This series of actions, combined with the action of magnetic force, is considered to be one of the factors that facilitate ozone water generation. The inventor is currently elucidating the causal relationship that the particle size R of the ozone bubbles can be reduced to 50 nm or less, but this point will be clarified in the experimental results described later.

[0013] (Characteristics of the invention described in claim 5)

In the substrate cleaning method according to the invention of claim 5 (hereinafter referred to as “the cleaning method of claim 5” t as appropriate), as a preferred embodiment of the cleaning method of claim 4, the magnetic force of the magnet is 1000-30000. It is set to Gauss.

[0014] According to the cleaning method of claim 5, on the premise of the action and effect of the cleaning method of claim 4, the configuration of the magnet can be performed easily and economically. In other words, a magnet with the above magnetic force is easy to procure on the market, so there is no need to prepare a special magnet. It's not a special magnet! The purpose is not to prevent the adoption of magnets with a magnetic force exceeding the above range. [0015] (Characteristics of the invention described in claim 6)

In the substrate cleaning method according to the invention described in claim 6 (hereinafter referred to as “cleaning method according to claim 6” as appropriate), ozone water (raw water) that has passed through the bench lily pipe is preferably used as the cleaning method according to claim 5. And is allowed to pass through the bench tube at least once while supplying ozone.

[0016] According to the cleaning method of claim 6, on the premise of the function and effect of the cleaning method of claim 5, ozone injection into ozone water can be repeatedly performed by circulating ozone water. If ozone injection is repeated, the ozone solubility and the ozone concentration can be increased in the latter than in the former by re-injecting ozone into the ozone water that has been and has been injected. By making ozone bubbles once dissolved repeatedly pass through the small path of the bench lily tube, miniaturization of the ozone bubbles is promoted. The number of circulations should be determined by the user of the device according to the required ozone solubility and ozone concentration.

[0017] (Characteristics of the invention of claim 7)

In the substrate cleaning method according to the invention of claim 7 (hereinafter referred to as “the cleaning method of claim 7”), as a preferred embodiment of the cleaning method of claim 6, the circulated ozone water is supplied to a storage tank. Once stored. Additional raw water may be injected into the storage tank in which ozone water is stored. This is to increase the amount of ozone water that has been reduced by use.

[0018] According to the cleaning method of claim 7, on the premise of the operational effect of the cleaning method of claim 6, ozone water can be stored in a storage tank, and ozone water can be stabilized by this storage. In this state, ozone dissolution in ozone water can be promoted by an action similar to aging. If ozone water is circulated while injecting raw water into the storage tank, a predetermined amount of ozone water can be stored in the storage tank while compensating for the decrease in usage. The ozone concentration is maintained by circulating ozone water.

[0019] (Characteristics of the invention described in claim 8)

In the substrate cleaning method according to the invention of claim 8 (hereinafter referred to as “the cleaning method of claim 8” as appropriate), as a preferred embodiment of the cleaning method of claim 7, ozone water stored in the storage tank is used. , Keep in the range of 0 to 15 ° C. To maintain the above temperature range For example, a method for directly adjusting the ozone water in the storage tank, a method for circulating the ozone water, and a method for returning the extracted ozone water to the storage tank after adjusting the temperature. Etc.

[0020] According to the cleaning method of claim 8, on the premise of the function and effect of the cleaning method of claim 7, by maintaining the temperature, ozone water (may contain newly injected raw water) The temperature can be maintained within the above range. The raw water used to generate ozone water is often transported in long pipes. The raw water transported in such cases is easily affected by the weather. In particular, the water temperature rises significantly in the summer. Further, in order to circulate ozone water, energy for circulation is necessary, and for example, there is a pump as such an energy source. The energy sources described above generally generate heat, and the heat may increase the temperature of ozone water (raw water). Ozone dissolution is affected by the water temperature. When the water temperature rises, the solubility decreases due to thermal decomposition of the ozone. Therefore, ozone dissolution is promoted by keeping the temperature of raw water (ozone water) within a predetermined range. On the other hand, for example, if ozone water (raw water) is likely to freeze in cold regions, a heater device may be provided to heat the ozone water (raw water) to be cleaned!ヽ. If cooling of ozone water (raw water) or calorie temperature is not required, the temperature holding structure itself may be omitted, or the operation of the provided temperature holding structure may be stopped.

[0021] (Features of the invention of claim 9)

In the substrate cleaning method according to the invention of claim 9 (hereinafter referred to as “the cleaning method of claim 9” as appropriate), ozone water is dissolved as a preferred embodiment in the cleaning method of any of claims 2 to 8. It is stored and promotes ozone dissolution.

[0022] According to the cleaning method of claim 9, on the premise of the operational effect of any of the cleaning methods of claims 2 to 8, ozone dissolution in ozone water is promoted by the action of the dissolution accelerating tank. The ozone water stored in the dissolution accelerating tank is placed in a stable state by the storage. Ozone water placed in a stable state is promoted by aging-like action for ozone dissolution. That is, the solubility of the ozone supplied to the raw water and the ozone further supplied to the ozone water to the raw water or the ozone water can be increased.

[0023] (Characteristics of the invention of claim 10) In the substrate cleaning method according to the invention of claim 10 (hereinafter, referred to as “cleaning method of claim 10” as appropriate), as a preferred embodiment of the cleaning method of claim 9, a reservoir is stored at the top of the dissolution promoting tank. The ozone deaerated from the ozone water is discharged.

[0024] According to the cleaning method of claim 10, on the premise of the operational effect of the cleaning method of claim 9, ozone that has not been dissolved in ozone water in the process of circulating ozone water can be discharged to the outside. . Since it is not always easy to completely eliminate undissolved ozone, undissolved ozone may exist. Most undissolved ozone floats to the surface because the particle size is not small enough. By discharging the ozone bubbles floating in this way (relatively large particle size) and leaving the small-diameter ozone bubbles, it is possible to increase the solubility of the ozone contained in the ozone water. As a result, ozone water with truly high ozone solubility is produced.

[0025] (Characteristics of the invention according to claim 11)

In the substrate cleaning method according to the invention of claim 11 (hereinafter referred to as “the cleaning method of claim 11” as appropriate), as a preferred embodiment of the cleaning method of any of claims 1 to 10, during ozone water cleaning, Then, radicals are generated by decomposing ozone in the ozone water on the substrate surface or an object to be cleaned (for example, a resist film) formed on or attached to the substrate surface (for example, an insulating film). The light having a wavelength that has a lower energy than the binding energy of the constituent material of the formed material on the substrate or the substrate is irradiated as necessary. Examples of light to be irradiated include an excimer laser, an excimer light, and a yag laser.

[0026] According to the cleaning method of claim 11, during the ozone water cleaning in any of the cleaning methods of claims 1 to 10, a radical is obtained by decomposing ozone into a cleaning object in which ozone water has permeated. In addition, light having a wavelength having an energy lower than the binding energy of the constituent material of the insulating film is irradiated. As a result, radicals are intensively generated in the object to be cleaned, and the decomposition reaction of the object to be cleaned is promoted in a state in which exposure of the substrate surface or the formation on the substrate surface to oxygen ions or oxygen radicals is suppressed. Can do. On the other hand, the bond between the generated energy and the bond energy is prevented from being broken by light irradiation in the constituent material of the formed material on the substrate or the substrate surface. this As a result, damage to the substrate or the formed product is suppressed, and the cleaning efficiency of the object to be cleaned is dramatically increased.

[0027] (Characteristics of the invention described in claim 12)

In the substrate cleaning method according to the invention of claim 12 (hereinafter referred to as “the cleaning method of claim 12” as appropriate), as a preferred embodiment of the cleaning method of any one of claims 1 to 10, ozone water is applied to the substrate. Let it flow. That is, for example, by flowing ozone water, stirring the ozone water, or vibrating the ozone water by irradiating ultrasonic waves, the ozone water in contact with the substrate is made fluid.

[0028] According to the cleaning method of claim 12, in addition to the operational effects of any of the cleaning methods of claims 1 to 10, ozone water (ozone bubbles) in contact with the substrate is constantly replaced by the flow of ozone water. Ozone water with a high ozone concentration can be contacted efficiently. In other words, ozone water (ozone) in contact with the substrate is decomposed by the reaction, but cleaning efficiency is increased by the reaction of new ozone water instead of the ozone water that has finished the reaction. Giving vibration to the object to be cleaned by running water also contributes to improving the cleaning efficiency.

[0029] (Characteristics of the invention of claim 13)

In the substrate cleaning method according to the invention of claim 13 (hereinafter referred to as “the cleaning method of claim 13” as appropriate), as a preferred embodiment of the cleaning method of any of claims 1 to 12, ozone water before contacting the substrate is used. Heat. There are no restrictions on the heating method, but for example, there are heaters, electromagnetic induction and steam heating methods. The heating temperature will depend on the temperature at the time of production, but for example, a range of 30 ° C to 80 ° C would be possible.

[0030] According to the cleaning method of claim 13, in addition to the operational effects of any of the cleaning methods of claims 1 to 12, efficient cleaning is achieved by raising the temperature of the ozone water to an appropriate temperature for cleaning. It can be performed. It is preferable that the appropriate temperature is generally high, which may depend on the nature of the object to be cleaned, the difference between local cleaning or total cleaning, the length of cleaning time, and other environments. On the other hand, ozone is more easily dissolved at a lower water temperature, and it is also true that ozone water is easily degassed and thermally decomposed. In the third prior art (Patent Document 3) introduced in the background technology section above, the force increased to 45 ° C, so far, it seems to be the limit in ozone water known so far. Because the particle size is 1 m (lOOOnm) level As described in the section of the problem to be solved by the invention, the ozone bubbles are in a state where the ozone bubbles are likely to rise to the water surface due to buoyancy from the ozone water. The particle size is further increased, and as a result, it is subjected to a greater buoyancy and is more likely to float. In this regard, since the ozone bubbles contained in the ozone water according to the present invention have a particle size of 50 nm or less, the buoyancy that is received even when expanded due to heating is small. Therefore, the ozone bubbles still remain in the ozone water and cannot be easily degassed. The reason why the ozone water according to the present invention could be raised to around 80 ° C. is presumed that the particle diameter of the ozone bubbles was sufficiently small.

[0031] (Characteristics of the invention according to claim 14)

In the substrate cleaning method according to the invention of claim 14 (hereinafter referred to as “the cleaning method of claim 14” as appropriate), as a preferred embodiment of the cleaning method of any one of claims 1 to 12, ozone water before contacting the substrate is used. Apply ultrasonic energy.

[0032] According to the cleaning method of claim 14, the ozone water obtained with the ultrasonic energy is more effective than the ozone water obtained with the effect of the cleaning method of any of claims 1 to 12, compared with the ozone water not obtained. Since the impact given to the substrate at the time of a collision is great, the cleaning effect can be enhanced by the magnitude of the impact. When energy is given to the ozone water or the conventional ozone water is shocked, it dissolves and the energy of ozone is easily degassed, but the ozone bubbles contained in the ozone water according to the present invention are 50 nm. Since it is below and is in a very stable state, it is not degassed, or even if it is degassed, there is very little.

[0033] (Characteristics of the invention described in claim 15)

In the substrate cleaning method according to the invention of claim 15 (hereinafter referred to as “the cleaning method of claim 15” as appropriate), as a preferred embodiment of the cleaning method of any one of claims 1 to 14, the substrate to be cleaned is a semiconductor. A semiconductor substrate represented by a wafer is used.

[0034] According to the cleaning method of claim 15, the semiconductor substrate can be cleaned extremely efficiently. Moreover, since it is additive-free ozone water, damage to the semiconductor substrate can be effectively suppressed. That is, the ozone water according to the cleaning method of claims 1 to 14 has a very small particle size of ozone bubbles contained therein, which is as small as 50 nm or less, so that ozone can be reacted even to small irregularities on the surface. Ideal for cleaning semiconductor substrates. [0035] (Characteristics of the invention according to claim 16)

In the substrate cleaning method according to the invention of claim 16 (hereinafter referred to as “the cleaning method of claim 16” as appropriate), as a preferred embodiment of the cleaning method of any of claims 1 to 14, the substrate to be cleaned is a liquid crystal A substrate is used.

[0036] According to the cleaning method of claim 16, the liquid crystal substrate can be cleaned extremely efficiently. Moreover, since it is additive-free ozone water, damage to the liquid crystal substrate can be effectively suppressed. That is, the ozone water according to the cleaning method of claims 1 to 14 has a very small particle size of ozone bubbles contained therein of 50 nm or less, so that the ozone can react even to small irregularities on the surface. This is ideal for cleaning liquid crystal substrates.

[0037] (Characteristics of the invention described in claim 17)

A substrate cleaning apparatus according to the invention of claim 17 (hereinafter referred to as “cleaning apparatus of claim 17” as appropriate) includes a cleaning tank for cleaning a substrate and ozone for supplying ozone water to the cleaning tank. And a water generator. Here, the ozone water generation apparatus includes a bench lily pipe having a small path and an ozone supply apparatus for supplying ozone to the water to be treated that passes through the small path of the bench lily pipe. Yes, pure water that is supplied with ozone or a magnet that acts purely magnetically on the bench lily tube can be configured to generate ozone water in which the particle size R of the contained ozone bubbles is 0 <R ≤ 50 nm It is.

According to the cleaning device of claim 17, the substrate cleaning is performed in the cleaning tank. The ozone water generator supplies the ozone water for cleaning. The bench lily pipe, which is the main component of the ozone water generator, supplies ozone to the treated water (pure water, ultrapure water, or ozone water) that passes through the small path. The ozone supply device performs ozone supply. The pressure of the water to be treated passing through the bench lily pipe increases rapidly as it approaches the small path, and decreases rapidly after passing through the small path. When the pressure decreases, the inside of the bench lily tube is in a vacuum or a negative pressure state close to vacuum, and ozone supplied by this negative pressure state is sucked into the raw water. The sucked ozone is agitated and mixed all at once, intricately intertwined with the change in pressure and the change in the flow of water to be treated as it passes through a small path. This series of actions, combined with the action of magnetic force, is considered to be one of the factors that facilitate ozone water generation. By applying a magnetic force to a small path As a result, the particle size of the ozone bubbles could be reduced to 50 nm or less. The causal relationship is currently being clarified by the inventor, but this point will be clarified in the experimental results described later. Since ozone water used for cleaning is not added, there is no possibility of adversely affecting the substrate due to mixing of additives. In addition, since no additives are mixed in, the ozone water after washing does not adversely affect the environment caused by the added calories. According to the manufacturing apparatus of claim 16, the cleaning method of claims 1 to 16 can be carried out.

[0039] (Characteristics of the invention according to claim 18)

In the substrate cleaning apparatus according to the invention of claim 18 (hereinafter referred to as “the cleaning apparatus of claim 18” as appropriate), as a preferred embodiment of the cleaning apparatus of claim 17, the magnet includes one magnet piece and the other magnet. The one magnet piece and the other magnet piece are opposed to each other with the bench tube interposed therebetween.

[0040] According to the cleaning device of claim 18, on the premise of the function and effect of the cleaning device of claim 17, a magnetic circuit is configured so that a magnetic force is applied intensively to a necessary portion inside the bench lily tube. it can. Intensive magnetic action increases the efficiency of ozone dissolution.

[0041] (Characteristic of the invention described in claim 19)

In the substrate cleaning apparatus according to the invention of claim 19 (hereinafter referred to as “the cleaning apparatus of claim 19” as appropriate), as a preferable aspect of the cleaning apparatus of claim 17 or 18, the magnetic force of the magnet is 1000 to 30000. It is set to Gauss.

[0042] According to the cleaning device of claim 19, on the premise of the operational effect of the cleaning device of claim 17 or 18, the configuration of the magnet can be performed easily and economically. In other words, if the magnet has the above magnetic force, it is not necessary to prepare a special magnet because it is easy to procure on the market. Since it is not a special magnet, it is inexpensive. The purpose is not to prevent the use of magnets with a magnetic force exceeding the above range.

[0043] (Characteristics of the invention described in claim 20)

In the substrate cleaning apparatus according to the invention of claim 20 (hereinafter, referred to as “the cleaning apparatus of claim 20” as appropriate), as a preferable aspect of the cleaning apparatus of any one of claims 17 to 19, it passes through the venturi tube. A circulation structure for circulating ozone water and passing it through the bench lily pipe is further included. [0044] According to the cleaning device of claim 20, on the premise of the operational effect of any of the cleaning devices of claims 17 to 19, by having a circulation structure, it is possible to circulate ozone water. Thus, ozone injection into ozone water can be repeated. If ozone injection is repeated, it is possible to increase the ozone solubility and the ozone concentration in the latter than in the former by re-injecting ozone into the ozone water that has been injected. The number of circulations should be determined by the user of the device according to the desired ozone solubility and ozone concentration.

[0045] (Characteristic of the invention described in claim 21)

In the substrate cleaning apparatus according to the invention of claim 21 (hereinafter referred to as “cleaning apparatus of claim 21” as appropriate), as a preferable aspect of the cleaning apparatus of claim 20, a substrate to be circulated is provided in the middle of the circulation structure. A storage tank for temporarily storing the treated water is provided. It may be possible to inject raw water into the storage tank where ozone water is stored! This is to increase the amount of ozone water that has been reduced by use. The concentration of ozone is reduced by the raw water injection, but the concentration can be increased by circulating it.

[0046] According to the cleaning device of claim 21, on the premise of the function and effect of the cleaning device of claim 20, ozone water can be stored in a storage tank, and this storage makes the ozone water stable. In this way, ozone dissolution in ozone water can be promoted by an action similar to aging. If ozone water is circulated while injecting raw water into the storage tank, a predetermined amount of ozone water can be stored in the storage tank while compensating for the decrease in usage. The ozone concentration is maintained by circulating ozone water.

[0047] (Feature of the invention of claim 22)

In the substrate cleaning apparatus according to the invention of claim 22 (hereinafter referred to as “the cleaning apparatus of claim 22” as appropriate), as a preferable aspect of the cleaning apparatus of claim 21, the liquid to be treated in the storage tank is 0 to A temperature holding structure is provided for holding in the range of 15 ° C. The temperature adjustment for maintaining the temperature range includes, for example, a method of directly applying ozone water in the storage tank or a method of returning the ozone water once taken out to the storage tank after temperature adjustment.

[0048] According to the cleaning device of claim 22, on the premise of the function and effect of the cleaning device of claim 21, By having the temperature holding structure, the temperature of ozone water (which may include newly injected pure water or ultrapure water) can be held in the above range. The raw water used to generate ozone water is often transported in long pipes. The raw water transported in such cases is easily affected by the weather. In particular, the water temperature rises significantly in the summer. In addition, in order to circulate ozone water, energy for circulation is necessary, and a source of such energy is, for example, a pump. The energy sources described above generally generate heat, which may increase the temperature of ozone water (raw water). Ozone dissolution is affected by water temperature, and as water temperature rises, solubility decreases. Therefore, ozone dissolution is promoted by keeping the temperature of raw water (ozone water) within a specified range. On the other hand, for example, if there is a risk that ozone water (raw water) may freeze in cold regions, a heater device may be provided to warm the ozone water (raw water) to be cleaned! / ヽ. If cooling or heating of ozone water (raw water) is not required, the temperature holding structure itself may be omitted or the operation of the provided temperature holding structure may be stopped.

[0049] (Characteristics of the invention described in claim 23)

In the substrate cleaning apparatus according to the invention of claim 23 (hereinafter referred to as “cleaning apparatus of claim 23” as appropriate), as a preferred embodiment of the cleaning apparatus of any of claims 17 to 22, the substrate is supplied to the cleaning tank. Alternatively, a heating means for heating the ozone water supplied to the cleaning tank is provided. There are no restrictions on the heating method, but for example, there are heating methods using a heater, electromagnetic induction and water vapor. The heating temperature will be a force depending on the temperature at the time of production. For example, a range of 30 ° C to 80 ° C will be possible.

[0050] According to the cleaning device of claim 23, in addition to the effect of the cleaning device of any of claims 17 to 22, efficient cleaning is achieved by raising the temperature of the ozone water to an appropriate temperature for cleaning. It can be performed. Appropriate temperature should be generally high as it may depend on the properties of the object to be cleaned and other environments. On the other hand, ozone is more easily dissolved when the water temperature is lower, so it is also true that ozone water is easily degassed. In the third prior art (Patent Document 3) introduced in the background technology section above, the temperature can be raised to 45 ° C! This is because ozone bubbles with a particle size of 1 μm (lOOOnm) are described in the column of problems to be solved by the above-mentioned invention. As described above, the ozone bubbles are in a state where they easily float to the water surface due to the ozone hydrodynamic buoyancy, and if heated there, the particle size becomes larger due to thermal expansion, and as a result, the buoyancy is further increased due to the larger buoyancy It is also a force that makes it easy to do. In this respect, the ozone bubbles contained in the ozone water according to the present invention have a particle size of 50 nm or less, so that the buoyancy that is received even when expanded by heating is small. Therefore, ozone bubbles still remain in the ozone water and do not easily deaerate. The reason why the ozone water according to the present invention could be raised to around 80 ° C. is presumed that the particle size of the ozone bubbles is sufficiently small.

[0051] (Characteristic of the invention described in claim 24)

In the substrate cleaning apparatus according to the invention of claim 24 (hereinafter referred to as “the cleaning apparatus of claim 24” as appropriate), as a preferred embodiment of the cleaning apparatus of any of claims 17 to 23, during the ozone water cleaning, Energy that generates radicals by decomposing ozone in the ozone water on the substrate surface or an object to be cleaned (for example, a resist film) formed on or adhered to a substrate surface or a formed material (for example, an insulating film). And a light source for irradiating light of a wavelength having energy lower than the binding energy of the constituent material of the substrate or the formed material on the surface of the substrate. Examples of the light emitted from the light source include an excimer laser, an excimer light, and a yag laser.

[0052] According to the cleaning apparatus of claim 24, during the ozone water cleaning in the cleaning apparatus of any of claims 17 to 23, radicals are decomposed by decomposing ozone into the cleaning target in a state where ozone water has permeated. In addition, light having a wavelength that has energy lower than the binding energy of the constituent material of the insulating film is irradiated. As a result, radicals are intensively generated in the object to be cleaned, and the decomposition reaction of the object to be cleaned is promoted in a state where exposure of the substrate surface or the formation on the substrate surface to oxygen ions or oxygen radicals is suppressed. Can advance. On the other hand, due to the difference between the generated energy and the binding energy, breakage of the bond due to light irradiation in the constituent material of the formed material on the substrate or the substrate surface is prevented. As a result, damage to the substrate or the formed product is suppressed, and the cleaning efficiency of the object to be cleaned is dramatically increased. [0053] (Characteristic of the invention described in claim 25)

In the substrate cleaning apparatus according to the invention of claim 25 (hereinafter referred to as “the cleaning apparatus of claim 25” as appropriate), as a preferred embodiment of the cleaning apparatus of any of claims 17 to 24, ozone before contact with the substrate is used. An ultrasonic vibration mechanism for providing ultrasonic energy is provided.

[0054] According to the cleaning device of claim 25, in addition to the operational effects of the cleaning method of any of claims 17 to 24, ozone water from which ultrasonic energy is also obtained by ultrasonic vibration mechanism force is not obtained. Since the impact given to the substrate at the time of substrate collision is larger than that of water, the cleaning effect can be enhanced by the magnitude of the impact. When energy is given to the ozone water or when the ozone water is impacted, the dissolved power of ozone is easy to degas V, but the ozone bubbles contained in the ozone water according to the present invention are Since it is 50 nm or less and is in a very stable state, even if it is not degassed or degassed, there is very little.

[0055] (Characteristic of the invention described in claim 26)

In the substrate cleaning apparatus according to the invention of claim 26 (hereinafter referred to as “the cleaning apparatus of claim 26” as appropriate), as a preferred aspect of the cleaning apparatus of any one of claims 17 to 25, the substrate to be cleaned is A semiconductor substrate typified by a semiconductor wafer is used.

[0056] According to the cleaning apparatus of claim 26, the semiconductor substrate can be cleaned extremely efficiently. Moreover, since it is additive-free ozone water, damage to the semiconductor substrate can be effectively suppressed. In other words, the ozone water according to the cleaning device of claims 17 to 25 has a very small particle size of ozone bubbles contained therein, which is as small as 50 nm or less, so that ozone can be reacted even to small irregularities on the surface. Ideal for cleaning semiconductor substrates.

[0057] (Characteristics of the invention according to claim 27)

In the substrate cleaning apparatus according to the invention of claim 27 (hereinafter referred to as “the cleaning apparatus of claim 27” as appropriate), as a preferable aspect of the cleaning apparatus of any one of claims 17 to 25, the substrate to be cleaned is A liquid crystal substrate is used.

[0058] According to the cleaning device of claim 27, it is possible to clean the liquid crystal substrate extremely efficiently. Moreover, since it is additive-free ozone water, damage to the liquid crystal substrate can be effectively suppressed. That is, the ozone water according to the cleaning device of claims 17 to 25 is contained in the ozone water. Since the Zon bubble has a very small particle size of 50nm or less, it can react with ozone even on small irregularities on the surface, making it ideal for cleaning liquid crystal substrates.

The invention's effect

[0059] According to the present invention, the substrate is not adversely affected! / And do not easily deaerate! Thus, it is possible to provide a substrate cleaning method and a substrate cleaning apparatus capable of obtaining a sufficient cleaning effect.

Brief Description of Drawings

FIG. 1 is a block diagram showing an example of a substrate cleaning method.

FIG. 2 is a block diagram of a semiconductor substrate cleaning apparatus.

FIG. 3 is a partial block diagram of a semiconductor substrate cleaning apparatus provided with an excimer lamp.

FIG. 4 is a block diagram of an ozone water generator provided in a semiconductor substrate cleaning apparatus.

FIG. 5 is a front view of a gas-liquid mixing structure.

FIG. 6 is a left side view of the gas-liquid mixing structure.

7 is an XX cross-sectional view of the gas-liquid mixing structure shown in FIG.

8 is a schematic plan view of the gas-liquid mixing structure shown in FIG.

FIG. 9 is a longitudinal sectional view of a dissolution promoting structure.

FIG. 10 is a view showing a modification of the semiconductor substrate cleaning apparatus.

FIG. 11 is a schematic configuration diagram of an ozone water generator for performing a comparative experiment.

FIG. 12 is a diagram for explaining the action of ozone bubbles.

FIG. 13 is a diagram for explaining the action of ozone bubbles.

FIG. 14 is a diagram for explaining the action of ozone bubbles.

Explanation of symbols

[0061] 1, 51 Semiconductor substrate cleaning apparatus

3 Washing tank

7 Cleaning mechanism

201 Ozone water generator

202 storage tank

203 Ozone supply device 204 Circulation structure

205 Gas-liquid mixing structure

206 Dissolution accelerating tank

207 Temperature holding structure

231 bench lily tube

232 Large upstream path

233 Aperture ramp

234 Small path

235 Open ramp

236 Downstream large path

239 Ozone supply pipe

243 Magnetic circuit

245 One magnet piece

246 The other magnet piece

265 Gas-liquid separator

267 Ozonizer

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for carrying out the invention (hereinafter referred to as “this embodiment” as appropriate) will be described with reference to the drawings. This embodiment relates to cleaning of a semiconductor substrate. The surface irregularities on the surface of the semiconductor substrate are currently at least 60 nm or less, and are probably the smallest of the various substrates, and are expected to be further reduced in the future. This is because if it can be used, it can be used for liquid crystal and other substrates. FIG. 1 is a block diagram illustrating an example of a substrate cleaning method. Fig. 2 is a block diagram of the semiconductor substrate cleaning apparatus. Fig. 3 is a partial block diagram of a semiconductor substrate cleaning apparatus provided with an excimer lamp. FIG. 4 is a block diagram of an ozone water generator provided in the semiconductor substrate cleaning apparatus. FIG. 5 is a front view of the gas-liquid mixing structure. Fig. 6 is a left side view of the gas-liquid mixing structure. FIG. 7 is an XX cross-sectional view of the gas-liquid mixing structure shown in FIG. FIG. 8 is a schematic plan view of the gas-liquid mixing structure shown in FIG. Figure 9 shows the longitudinal profile of the dissolution promoting structure FIG. FIG. 10 is a view showing a modification of the semiconductor substrate cleaning apparatus. FIG. 11 is a schematic configuration diagram of an ozone water generator for performing a comparison experiment. 12 to 14 are diagrams for explaining the action of ozone bubbles.

[0063] (Substrate cleaning method)

An example of the semiconductor substrate cleaning method will be described with reference to FIG. The semiconductor cleaning method begins with the ability to generate ozone water (Sl). Here, the generated ozone water is performed by a gas-liquid mixing method in which ozone is mixed with pure water or ultrapure water. Ozone water is generated without adding any additives. The reason for not adding was to prevent the additive from adversely affecting the semiconductor substrate. Particle size of ozone bubbles contained in generated ozone water

R is set to 0 <R≤50 nm. This is to effectively suppress ozone degassing and dramatically increase cleaning efficiency. A suitable ozone concentration is, for example, around 15 to 30 ppm. The generated ozone water may be heated as necessary (S2). Although it depends on the nature of the object to be cleaned and other environments, the cleaning effect is enhanced by heating. The heating temperature is a force depending on the temperature at the time of generation and other environments. This is not intended to exclude heating outside the temperature range, but if the temperature falls below 30 ° C, the cleaning efficiency is not improved sufficiently by heating. If the temperature exceeds 80 ° C, ozone will be easily degassed.

[0064] The generated ozone water and, if necessary, the heated ozone water are used to clean the semiconductor substrate. The cleaning method can be appropriately selected according to the type of the semiconductor substrate and other environments. For example, a showering method in which ozone water is poured in a shower, a spin cleaning method in which ozone water is supplied onto a rotating semiconductor substrate, an immersion cleaning method in which the semiconductor substrate is relative to a batch cleaning tank containing ozone water, and the like. A combination of these methods is a cleaning method using ozone water. At the same time, the ozone water can be made to flow by irradiating the ozone water with ultrasonic waves. A reaction promoting step such as irradiating excimer light or the like can be included as needed during ozone water cleaning (S7). Furthermore, methods other than those described above can be used in combination before and after ozone water cleaning as needed.

[0065] (Schematic structure of semiconductor substrate cleaning apparatus)

Referring to FIG. 2, the semiconductor substrate cleaning method according to this embodiment is performed. A semiconductor substrate cleaning apparatus (hereinafter referred to as “cleaning apparatus” as appropriate) will be described. The cleaning apparatus 1 is generally composed of a cleaning tank 3, an ozone water generation apparatus 201, and the like. The cleaning tank 3 is a tank for cleaning the semiconductor substrate W therein. Inside the cleaning tank 3, a cleaning mechanism 7 for assisting the cleaning of the semiconductor substrate is arranged. The ozone water generator 201 is an apparatus for supplying ozone water to the cleaning tank 3.

[0066] (Outline of cleaning tank and cleaning mechanism)

The outline of the cleaning tank and the cleaning mechanism will be described with reference to FIG. The cleaning tank 3 indicated by a two-dot chain line in FIG. 2 is configured to be substantially confidentially sealed and has an opening / closing mechanism (not shown) for entering and exiting the semiconductor substrate A. The cleaning mechanism 7 installed in the cleaning tank 3 is generally composed of a motor 7m as a driving source and a rotary table 7t rotated by the motor 7m. The turntable 7t is configured such that the semiconductor substrate A can be placed thereon, and the semiconductor substrate A is configured to be able to rotate integrally while holding the semiconductor substrate A downward. The reason for rotating the semiconductor substrate A is to increase the cleaning efficiency by spreading the ozone water W evenly. The rotation of the motor 7m is configured to be controllable by a rotation speed control device 7c outside the cleaning tank 3. Reference numeral 11 indicates a nozzle for discharging the ozone water W supplied from the ozone water supply device 201 onto the surface of the semiconductor substrate A. The nozzle 11 is movably held by a nozzle drive device 13 installed in the cleaning tank 3, and is configured to change the discharge position of the ozone water W with respect to the semiconductor substrate A by the movement. The reason for changing the discharge position is to distribute the ozone water W more evenly by the position change. The nozzle drive device 13 is controlled by a position control device 13c outside the cleaning tank 3. The cleaning tank 3 and the cleaning mechanism 7 described above are configured for cleaning a semiconductor substrate. However, when cleaning a substrate other than the semiconductor substrate or other electronic components, the type, number, etc. of the cleaning components should be considered. Needless to say, a combined washing tank and washing mechanism should be constructed. The symbol R indicates the resist film (object to be cleaned) formed on the surface of the semiconductor substrate A! /

Further, as shown in FIG. 3, the cleaning apparatus 1 is provided with a light source 8 as necessary to irradiate an excimer laser (excimer light) 8L onto the semiconductor substrate A supplied with ozone water W. You can also. Excimer laser is irradiated with ozone water by its energy. This is because radicals are generated by decomposing ozone in the atmosphere. The generation of radicals promotes breakage of bonds in the resist film R when, for example, the resist film R remains on the surface of the semiconductor substrate A. The energy of the excimer laser needs to be lower than the binding energy of the semiconductor substrate A (or the insulating film when the insulating film is formed on the surface). This is to suppress damage to the semiconductor substrate A. The light source 8 is configured so that excimer lamp power (not shown) can also be irradiated with excimer light guided through the light guide line 8a. You may comprise so that other light (for example, Jag light) which shows the effect similar to the said excimer light may be irradiated instead of an excimer light. Further, the nozzle 11 may be provided with an ultrasonic vibration mechanism 1 la so that the nozzle tip 1 lb is vibrated forward and backward along the discharge direction, thereby applying ultrasonic energy to the ozone water W. This is because the resist film R is easily peeled off by impacting the semiconductor substrate A with ultrasonic energy. The light source 8 and the ultrasonic vibration mechanism 11a (nozzle tip l ib) function as a reaction promoting mechanism for ozone water (ozone).

[0068] (Outline of ozone water generator)

The ozone water generator will be described with reference to FIG. The ozone water generation apparatus 201 includes a storage tank 202, an ozone supply apparatus 203 for generating and supplying ozone, a circulation structure 204 for returning treated water taken out from the storage tank 202 to the storage tank 202, a circulation The gas-liquid mixing structure 205 and dissolution accelerating tank 206 provided in the middle of the structure 204, the temperature holding structure 207 attached to the storage tank 202, and the force are also generally configured. For convenience of explanation, the following explanation will be made for the circulation structure 204 after the storage tank 202, the temperature holding structure 207, the ozone supply device 203, the gas-liquid mixing structure 205, and the dissolution promoting tank 206.

[0069] (Structure around the storage tank)

As shown in FIG. 4, the storage tank 202 is configured to be able to inject raw water (pure water or ultrapure water) as treated water through a water intake valve 202v. The storage tank 202 is for storing raw water taken and water to be treated (ozone water) circulated through a circulation structure 204 described later. The water to be treated stored in the storage tank 202 is held in the range of 0 to 15 ° C. by the temperature holding structure 207, for example. The temperature was set within the above range because ozone was dissolved efficiently and the dissolved ozone was easily degassed. It is a force that is suitable for not. The reason why less than o ° c is not included in the above range is that ozone water freezes below o ° c. The temperature holding structure 207 is generally composed of a pump 211 for taking out the treated water from the storage tank 202, a cooler 212 for cooling the taken out treated water, and a force. The storage tank 202 and the pump 211, the pump 211 and the cooler 212, and the cooler 212 and the storage tank 202 are connected by a pipe 213 through which the water to be treated is passed. With the above configuration, the water to be treated (raw water and Z or ozone water) stored in the storage tank 202 is taken out of the storage tank 202 by the action of the pump 211 and sent to the cooler 212. The cooler 212 cools the treated water sent to a temperature within a predetermined range and returns it to the storage tank 202. The pump 211 operates only when the temperature of the water to be treated in the storage tank 202 measured by a thermometer outside the figure exceeds a predetermined range and needs to be cooled. The reason for providing the storage tank 202 is that the water to be treated is stored once to enable the cooling, and the water to be treated is placed in a stable state, thereby aging ozone dissolution in the water to be treated. This is because it is promoted by a similar action. For example, when there is a possibility that the water to be treated will freeze in a cold district, etc., the water to be treated is heated using a heater device in place of the cooler or together with the cooler. You can also Note that ozone water is supplied to the cleaning device 1 via a pipe 213a branched from the pipe 213. That is, the ozone water cooled to a predetermined temperature by the cooler 212 is supplied to the cleaning device 1 through the pipe 213a by the action of the pump 211. Reference numeral 213v indicates an adjustment valve for adjusting the flow rate of ozone water provided in the pipe 213a.

(Ozone supply device)

An ozone supply device 203 shown in FIG. 4 is a device for generating and supplying ozone. There is no limitation on the principle of ozone generation that the ozone supply device 203 operates as long as the necessary amount of ozone can be supplied. For example, a discharge method in which ozone is generated by causing discharge in oxygen gas, and an electrolysis method in which ozone is generated by electrolyzing water molecules in ultrapure water are known as ozone generation methods. The ozone generated by the ozone supply device 203 is supplied to the gas-liquid mixing structure 205 through an electromagnetic valve 218 and a check valve 219 provided in the middle of the ozone supply pipe 217. [0071] (Gas-liquid mixing structure)

Details of the gas-liquid mixing structure 205 will be described with reference to FIGS. The gas-liquid mixing structure 205 is generally constituted by a bench lily pipe 231, an ozone supply pipe 239, and a magnetic circuit 243. The bench lily pipe 231 is used to pass the treated water (pure water, ultrapure water, ozone water) sent from the upstream side (right side as viewed in Fig. 5) to the downstream side (left side as shown in Fig. 5). It has a noise-like appearance (see Fig. 8). The hollow space penetrating the bench lily pipe 231 in the longitudinal direction communicates from the upstream side to the downstream side in the order of the upstream large path 232, the throttle ramp 233, the small diameter path 234, the open ramp 235, and the downstream large path 236. ing. The upstream large path 2 32 is connected to a small-diameter path 234 via a throttle ramp 233 that is inclined in the throttle direction with a steep angle of about 50 degrees with respect to the axial direction. It opens with a gentle angle of around 30 degrees. The open ramp 235 is connected to the downstream large path 236 having the same outer diameter as the upstream large path 232. On the other hand, the open end of the ozone supply pipe 239 faces the small path 234. An ozone supply pipe 217 communicating with the ozone supply device 203 is connected to the supply end of the ozone supply pipe 239. The inside of the small path 234 or the vicinity thereof becomes a vacuum or a state close to a vacuum due to a change in the pressure of the water to be treated, so that ozone that has reached the open end is aspirated and diffused into the water to be turbulent. Is done. Reference numeral 240 shown in FIG. 7 indicates a rib for reinforcing the space between the bench lily pipe 231 and the ozone supply pipe 239.

A magnetic circuit 243 is fixed to the bench lily tube 231 with a screw (not shown). The magnetic circuit 243 connects one magnet piece 245 and the other magnet piece 246 facing each other with the bench lily pipe 231 therebetween, and connects the one magnet piece 245 and the other magnet piece 246 to the bench lily pipe 23 1. And a connecting member 248 having a U-shaped cross section (see FIG. 6) having a function of attaching a magnet piece. The magnet piece 245 and the magnet piece 246 have a small path 234 (shown by a broken line in FIG. 8) (see also FIG. 7) and Z or its vicinity (especially the downstream side) through the most magnetic lines of force (magnetic field). It is good to arrange like this. However, in practice, it is technically difficult to concentrate the magnetic lines of force only on the small path 234, so that the magnetic lines of force will pass through both the small path 234 and the vicinity of the small path 234. It is considered that ozone can be dissolved most efficiently in the water to be treated by applying a magnetic force to both the water to be treated and ozone. Power is also. The magnet piece 245 and the magnet piece 246 are composed of neodymium magnets having a magnetic force of around 7,000 gauss. The stronger the magnetic force, the higher the ozone dissolution effect is. At least 1,000 gauss or more is desired. Here, 7,000 gauss magnets were used because of their ease of procurement and economy. This is not to prevent the adoption of magnets (natural magnets, electromagnets, etc.) with a magnetic force of 7,000 Gauss or more. Further, the distance between the magnet piece 245 and the magnet piece 246 is preferably as short as possible. Because the magnetic force is inversely proportional to the square of the distance, the shorter the magnetic force, the stronger the magnetic force that can be obtained. The connecting member 248 is configured by a member (for example, iron) having a large magnetic permeability () so that the magnetic flux action is concentrated as much as possible on the water to be treated and the like, while suppressing magnetic flux leakage.

[0073] (Function and effect of gas-liquid mixing structure)

With the above configuration, the water to be treated that has passed through the upstream large path 232 is compressed when passing through the throttle ramp 233, and the water pressure increases rapidly, and at the same time, the passing speed also increases rapidly. The high-pressure 'high-speed peak is when the small path 234 is reached. The treated water that has passed through the small path 234 suddenly depressurizes and decelerates in the open ramp 235, and becomes turbulent due to the impact of collision with the subsequent treated water. Thereafter, the water to be treated passes through the large downstream path 236 and goes out of the gas-liquid mixing structure 205. The diffused ozone is entrained in the turbulent flow of the water to be treated, becomes bubbles of various sizes, and is agitated. The small path 234 and at least the water to be treated (ozone water) flowing downstream thereof are subjected to the magnetic action of the magnetic circuit 243 along with the stirring action. In other words, the pressure of the water to be treated is increased to the pressure peak (peak), the pressure is reduced immediately after reaching the peak of pressure, and ozone is supplied to the water to be treated that has reached the peak of pressure. Will be done. The stirring action and the magnetic action of the magnetic field produce a synergistic effect. As a result, ozone is dissolved in the water to be treated and high-concentration ozone water with high solubility is generated.

[0074] (Dissolution promotion tank)

The dissolution accelerating tank 206 will be described with reference to FIGS. The dissolution accelerating tank 206 is configured by a cylindrical outer wall 255 whose upper and lower ends are sealed by a top plate 253 and a bottom plate 254. A cylindrical inner wall 256 is also provided on the lower surface of the top plate 253 so that the lower surface force also hangs down. Spatial force surrounded by inner wall 256 Storage chamber for storing treated water 25 8 The outer diameter of the inner wall 256 is set to be smaller than the outer diameter of the outer wall 255, whereby an inter-wall passage 259 having a predetermined width is formed between the inner wall 256 and the outer wall 255. On the other hand, the lower end of the inner wall 256 does not reach the bottom plate 254 and forms a gap having a predetermined width with the bottom plate 254. This gap functions as a lower end communication path 257. That is, the storage chamber 258 surrounded by the inner wall 256 communicates with the inter-wall passage 259 through the lower end communication passage 257. On the other hand, a plurality of communication holes 256h, 256h, ... are penetrated in the vicinity of the top plate 253 of the inner wall 256, and the storage chamber 258 and the passageway 259 between the walls communicate with each other through each communication hole 256h. RU In the center of the upper surface of the bottom plate 254, an elongated pumping pipe 261 is erected. The lower end of the hollow portion of the pumping pipe 261 communicates with a water inlet hole 254h penetrating the bottom plate 254, and the upper end of the hollow portion communicates with a storage chamber 258 via a number of small holes 26 lh formed at the upper end of the pumping pipe 261. is doing. The upper end of the pumping pipe 261 is positioned slightly below the position of the communication hole 256h where the inner wall 256 is provided. A drainage hole 255h is penetrated in the vicinity of about a quarter from the top of the outer wall 255 in the height direction. That is, the inter-wall passage 259 communicates with the outside through the drain hole 255h.

A pumping hole 253h is passed through substantially the center of the top plate 253. The pumping hole 253h communicates with the inside of the gas-liquid separator 265 disposed outside the top plate 253. The gas-liquid separator 265 functions as a deaeration structure for separating and discharging the water to be treated pushed up from the storage chamber 258 through the pumping hole 253h and the ozone deaerated from the water to be treated. The ozone separated by the gas-liquid separation device 265 is decomposed and detoxified by the ozone decomposition device 267, and then released to the outside of the device. The ozone solubility in the water to be treated is extremely high. Therefore, the amount of ozone to be deaerated is extremely small, but an ozone decomposing device 267 and the like are provided for further safety. The treated water sent into the storage chamber 258 by the pumping pipe 261 is pushed by the subsequent treated water and descends. The treated water that has reached the lower end is folded back at the lower end communication passage 257, rises in the inter-wall passage 259, and is discharged to the outside through the drain hole 255h. A part of the water to be treated is pushed up into the gas-liquid separator 265. During this time, ozone dissolves in the water to be treated due to an aging-like action, producing highly soluble ozone water. On the other hand, if there is a force that cannot be completely dissolved, or there is ozone that has been dissolved but degassed, the ozone rises into the gas-liquid separator 265 and is separated there. Therefore, most of the ozone that cannot be completely dissolved from the treated water can be eliminated. As a result, The ozone solubility of the treated water that has passed through the dissolution accelerating tank 206 is dramatically increased! / The gas-liquid separation device 265 and the ozonolysis device 267 can be provided in place of the dissolution promoting tank 206 or in the storage tank 202 and other places together with the dissolution promoting tank 206.

[0076] (Circulating structure)

The circulation structure will be described with reference to FIG. The circulation structure 204 has a function of circulating the water to be treated that has passed through the gas-liquid mixing structure 205 (which is already raw hydro-ozone water) and passing it again through the gas-liquid mixing structure 205. The reason why the gas-liquid mixing structure 205 is passed again is to further increase the solubility and concentration of ozone by injecting ozone again into the water to be treated in which ozone has already been dissolved. The circulation structure 204 has a pump 271 as a drive source and a storage tank 202 and a dissolution promoting tank 206 as main components. That is, the pump 271 pumps the water to be treated taken out from the storage tank 202 through the pipe 270 to the gas-liquid mixing structure 205 through the check valve 272 and the pipe 273. The treated water that has passed through the gas-liquid mixing structure 205 by pressure feeding passes through the pipe 274 and the dissolution accelerating tank 206 and is returned to the storage tank 202 through the pipe 275. The circulation structure 204 is configured such that the above-described steps can be repeated as necessary. The number of circulations can be freely set in order to obtain ozone solubility, ozone concentration, etc. of ozone water to be generated. Reference numeral 276 indicates a valve provided in the middle of the pipe 275. The nozzle 276 is provided mainly for controlling the water pressure of the water to be treated that passes through the small path 234 (see FIG. 7) of the gas-liquid mixing structure 205 by opening and closing.

[0077] (Heating means)

The ozone water generator 201 is provided with heating means for heating the generated ozone water before supplying it to the treatment tank 3. This is to increase the temperature of the ozone water before contacting the semiconductor substrate as necessary, thereby increasing the cleaning efficiency. The heating means is constituted by a heater H. The heater 8 can be composed of a heating element, an in-line induction heater using electromagnetic induction, a high-temperature steam generator, and the like.

[0078] (Modification of Cleaning Device)

A modification of the treatment tank 3 will be described with reference to FIG. Processing according to this modification The tank 53 is supplied with ozone water W from the ozone water generator 201 (not shown in FIG. 10) via the supply nozzles 54 and 54. In the processing bath 53, a wafer port 56, “is arranged so as to be movable up and down, and the wafer port 56,... Is a plurality of semiconductor substrates A,. The semiconductor substrate A, ··· supported is immersed in ozone water W stored in the treatment tank 53 and cleaned. The stored ozone water W is overflowed from the upper surface of the treatment tank 53 by the subsequent supply of the ozone water W, and is provided at the upper end of the overflowed ozone water Wha treatment tank 53. The ozone water W is additionally supplied from the drainage channels 55 and 55. The ozone water W is constantly flowed, so that the concentration of ozone water W is reduced instead of the ozone water W, which has been lowered after the reaction. High ozone water W is brought into contact with the semiconductor substrate, and the surface of the semiconductor substrate A depends on the impact of flow. The ozone water W drained from the drainage channels 55 and 55 is reused by, for example, filtering or remixing ozone. It can also be done.

(Experimental example)

An experimental example will be described with reference to FIGS. The experimental examples shown here are mainly intended to show that there is a significant difference in the solubility and concentration of ozone due to the difference in the method of using the magnet described in the background technology column and the method of using the magnet according to the present invention. It is. In this experimental example, the ozone water generating device (hereinafter referred to as “the present device”) shown in FIG. 4 is used as the device according to the present invention, and the ozone water generating device (hereinafter referred to as “the device”) shown in FIG. Used as a comparison device). In the comparison device, only the mounting position of the force magnetic circuit 243 provided with basically the same structure as that of the present device is different. Therefore, in FIG. 11, the same reference numerals as those used in FIG. 4 are used except for the magnetic circuit. In the magnetic circuit shown in FIG. 11, reference numeral 243a is assigned to the upstream side of the gas-liquid mixing structure 205, and Some are labeled 243b. In summary, the present apparatus shown in FIG. 4 includes a gas-liquid mixing structure 205 integrated with a magnetic circuit 243, and the comparison apparatus shown in FIG. 11 includes a magnetic circuit 243a in the upstream piping of the gas-liquid mixing structure 205. Similarly, the magnetic circuit 243b can be attached to or removed from the downstream pipes simultaneously or selectively. As the gas-liquid mixing structure 205, MAJEIJIN INJECTOR CORPORATION) model 384 and magnetic circuit of 7000 Gauss were used.

[0080] (Concentration comparison experiment)

The concentration comparison experiment will be described with reference to Tables 1 and 2. Table 1 shows the relationship between the ozone concentration of ozone water and the concentration rise time. Table 2 shows the time required for the ozone concentration shown in Table 1 to reach zero after the generator is shut down. The longer it takes to reach zero, the higher the ozone solubility. In Tables 1 and 2, the symbol “mouth” represents ozone water generated by using the present device (hereinafter referred to as “the present ozone water”), and the symbol “X” represents the atmosphere obtained by removing only the magnetic circuit from the comparison device. Ozone water generated using a liquid-mixed structure (hereinafter referred to as “magnetic-free ozone water”), and the symbol “△” represents ozone water (hereinafter referred to as “water-free mixed water” 205 and magnetic circuit 243a) in the comparison device. The symbol “◯” indicates ozone water generated by the gas-liquid mixing structure 205 and the magnetic circuit 243b in the comparison device (hereinafter referred to as “downstream magnetic ozone water”), The symbol “◊” represents ozone water generated by the gas-liquid mixing structure 205 and both the magnetic circuit 243a and the magnetic circuit 243b in the comparison device (hereinafter referred to as “bilateral magnetic ozone water!”). It is shown. The temperature of the treated water was 5 ° C, the ambient humidity was 36-43%, and the ambient temperature was 17 ° C.

[0081] [Table 1]

[0082] [Table 2]

E u¾ o m o m o

As Table 1 shows, the ozone water reached an ozone concentration of 20 ppm after 35 minutes after the start of the generator operation. Under the same conditions, the ozone water without magnetism had an ozone concentration of around 8 ppm and the downstream magnetic ozone. Water has an ozone concentration of about l lppm. The concentration of ozone was around 12 ppm, and the magnetic ozone water on both sides increased only to an ozone concentration of around 13 ppm. From this, it is possible to increase the ozone concentration by providing a magnetic circuit first, compared to the case where the magnetic circuit is not provided. In the case where it is installed in a place other than the mixed structure, it was found that the former can generate ozone water at least 7 ppm higher than the latter. In other words, the ozone concentration of this case was about 54% ((20-13) Z1 3 X 100) higher than the double-sided magnetic ozone water.

[0084] As shown in Table 2, it took 32 hours or more for the ozone concentration of the ozone water that reached 20 ppm to reach zero, whereas it was the longest among the ozone waters to be compared. The concentration of ozone on both sides of the magnetic ozone water was about 3.5 hours. Therefore, the ozone water contained ozone for approximately 10 times longer than the two-sided magnetic ozone water. In other words, compared with the magnetic ozone water on both sides, the present ozone water kept the ozone dissolved by injecting the same amount of ozone over the same time for about 10 times. This shows the high ozone solubility of the ozone water.

[0085] (Ozone bubble particle size measurement experiment)

With reference to Tables 3 and 4, the particle size measurement experiment of ozone bubbles contained in the ozone water will be explained. Tables 3 and 4 show the particle size distribution of the ozone bubbles contained in the ozone water (see vertical axis on the left). In this measurement experiment, four types of ozone water were measured in the relationship between ozone concentration and ozone concentration retention time. First, the ozone concentration is 3 ppm and 14 ppm. Next, ozone water immediately after reaching each concentration (hereinafter referred to as “3 ppm immediately after ozone water” and “14 ppm immediately after ozone water”), After reaching the concentration, it was divided into ozone water that was maintained for 15 minutes (hereinafter referred to as “3 ppm maintenance ozone water” and “14 ppm maintenance ozone water”, respectively). In other words, it is the measurement target for the four types of measurement experiments: “Ozone water immediately after 3 ppm”, “Ozone water after 3 ppm”, “Ozone water immediately after 14 ppm”, and “14 ppm ozone water”. Here, pure water obtained by filtering tap water through a reverse osmosis membrane of 0.05 m (50 nm) fine particle absolute filtration was used as the raw water of the ozone water used in this measurement experiment. The equipment used for obtaining pure water in this experiment was an ultrapure water system (model name: Model) • UHP). Since tap water contains impurities of 50 nm or more (for example, iron and magnesium), even if ozone water generated from unfiltered raw water is measured, the impurities contained therein are measured, resulting in measurement errors. Therefore, it is possible to correctly measure the bubble size of ozone by removing impurities in advance by filtration. The same can be said for raw water other than tap water, such as well water and river water. The measuring instrument used for measuring the particle size of ozone bubbles is a dynamic light scattering particle size distribution measuring device (HORIBA, Ltd .: model LB500). Needless to say, if there is a means that can correctly measure the particle size of ozone bubbles without filtering impurities from the raw water, that means can be used.

[0086] [Table 3]

() 03 0. 010 0. 100 1. 000 6. () 00

Particle size (i m)

[0087] [Table 4]

0.003 0.010 0.100 1.000 6.000

Particle size (ium)

[0088] First, based on Table 3, the ozone water immediately after 3 ppm and the 3 ppm maintained ozone water will be considered. The rightmost graph in Table 5 shows the ozone water immediately after 3ppm, and the leftmost graph shows the ozone water maintained at 3ppm. It was found that the ozone water immediately after 3 ppm contained ozone bubbles having a particle size of 1.3 πι (1300ηπι) to 6.0 ^ πι (60 OOnm). On the other hand, it was found that the ozone water maintained at 3 ppm contained ozone bubbles having a particle size of 0.0033 nm (3.40 nm) to 0.0050 m (5. OOnm).

[0089] Next, based on Table 4, the ozone water immediately after 14 ppm and the ozone water that maintains 14 ppm are considered. The rightmost graph in Table 6 shows ozone water just after 14ppm, and the leftmost graph shows 14ppm maintained ozone water. It was found that the ozone water immediately after 14 ppm contained ozone bubbles having a particle size of 2.3 m (2300 nm) to 6. μm (6000 nm). On the other hand, it was found that the 14 ppm maintenance ozone water contained ozone bubbles having a particle size of 0.0033 nm (3.40 °) to 0.0054 m (5.80 °).

[0090] The first point clarified from the above experiment is that even with ozone water having the same concentration, ozone water immediately after reaching the concentration (immediately after ozone water) and the concentration are maintained for a predetermined time. The ozone water (maintened ozone water) is different in the particle size of the ozone bubbles (hereinafter referred to as “bubble particle size” t). In the case of 3ppm ozone water, the minimum bubble size of ozone water immediately after is 260 times (1300Z5.0) the maximum bubble size of maintenance ozone water. . Similarly, the 14ppm ozone water is about 400 times larger (2300Z5.8). That is, it is possible to reduce the bubble particle size by maintaining the concentration for a predetermined time, that is, by circulating ozone water as the water to be treated. If the bubble diameter is lOOOnm or less, preferably 500 nm or less, and more preferably ozone bubbles having a bubble diameter of less than 50 nm, they can be more stably suspended in the aqueous solution. According to the ozone water treatment method according to the present invention, ozone water containing ozone bubbles having a particle size R force of less than 5 Onm (0 <R <50 nm), that is, ozone water having high solubility, is generated. It turns out that it is obtained. Ozone water containing ozone bubbles of 50 nm to 1000 nm can be obtained in the process of generating ozone water having a particle diameter of less than 50 nm. In other words, ozone water generated without circulation or ozone water with reduced circulation time has a larger particle size than ozone water produced by circulation or longer circulation time and ozone water. It is advisable to adjust the presence / absence of circulation and the circulation time according to the particle size. In addition to the above, it may be fluctuated depending on the water pressure in the circulatory system, the strength of the magnets acting on the bench lily pipe, the concentration and amount of supplied ozone, and the atmosphere in which it is generated. This is the second point that became clear from the experiment. In addition, according to this experiment, the minimum measured value of the particle size R of ozone bubbles is 3.4 nm, and values below that are measured! This is probably due to the limitations of the measuring capability of the measuring device. On the other hand, since the particle size R of the ozone bubbles is smaller after the concentration is maintained than immediately after the concentration is achieved, the ozone bubbles having a particle size R that is almost zero on the extension line of particle size reduction. Can easily be imagined.

(pH measurement experiment)

A pH measurement experiment was conducted on the above four types of ozone water, namely “3 ppm ozone water”, “3 ppm maintenance ozone water”, “14 ppm ozone water” and “14 ppm maintenance ozone water”. The results are shown as line graphs in Tables 5 and 6 (see right vertical axis). All ozone waters showed a pH of around 7.3 before and after ozone dissolution. In other words, it may O zon dissolution does not give little change in _P H of the raw water ChikaraTsuta. Well water and tap water are almost neutral (pH 6.5-7.5), so the zonal water produced by the gas-liquid mixing method does not require any additives to adjust the pH. The neutrality was confirmed. Also In any case, if the raw water is alkaline, it may be possible to produce alkaline ozone water because ozone dissolution does not change the pH of the ozone water.

[0092] The above experimental results will be summarized. The ozone water that was the subject of the experiment was generated by gas-liquid mixing in which ozone was mixed with the raw water without adding any additives. Furthermore, ozone is not easily degassed even under normal pressure because of high ozone solubility. Therefore, if this ozone water is used, it is possible to obtain a more efficient cleaning effect without adversely affecting the semiconductor substrate.

[0093] (Resist film cleaning experiment)

An experimental apparatus with a simplified treatment tank 53 shown in FIG. 10 was created, and a resist film cleaning (peeling) experiment using ozone water W was performed. The cleaning experiment was conducted using two types of silicon wafer substrates. One silicon wafer substrate (hereinafter referred to as “sample substrate 1”) is a substrate that has been subjected to an in-batch calorie treatment by applying a novolac photoresist film on a silicon wafer substrate and baking it at 120 ° C. for 20 minutes. The size of the sample substrate 1 was 25 mm × 25 mm, and the thickness of the photoresist film was 1 m. As sample substrate 1, five samples from sample substrates 1-1 to 1-5 were used as samples (see Table 5). The other silicon wafer substrate (hereinafter referred to as “sample substrate 2”) is a substrate that is baked at 160 ° C. for 20 minutes after a novolac photoresist film is applied on the silicon wafer substrate. The sample substrate 2 is not subjected to the imbracate treatment. The size of the sample substrate 2 was 25 mm × 35 mm, and the film thickness of the photoresist film was also 1 μm. Sample substrate 2 is sample substrate 2-1 to 2-6 with 3 samples as sample, sample substrate 2-1-2-3 is ozone water W, sample substrate 2-4-2-6 is Ozone water for comparison was included (see Table 6). The particle size of ozone bubbles contained in the comparative ozone water is estimated to be: m or more. The raw water of ozone water W is tap water, and the particle size R of ozone bubbles contained in ozone water W was 0 <R≤50nm. Each sample substrate was immersed in a treatment tank (not shown) in which ozone water W was stored, and ozone water W with a water pressure of about 0. IMPa was jetted near its center. Table 5 and Table 6 show the temperature change and stripping rate of ozone water W. As a result of setting the amount of ozone (ozone gas) to 50 gZNm ³ , the dissolved ozone concentration was 29 to 27 mg / L (g / Nm ³ ) as shown in Table 5 and Table 6.

[0094] [Table 5] Ozone; ks¾

. c / min p pm: mg / min

70 0. 3 29 1. 900

60 0. 4 29 1. 100

I5S * 4S¾1 -3 50 0. 6 29 0. 400

Ii¾ «¾1-4 35 0. 6 29 0. 040

IS * «* 5l-5 7 0. 6 29 0. 003

[0095] [Table 6]

[0096] First, referring to Table 5, the experimental results of the sample substrate 1 will be discussed. When the ozone water temperature was 7 ° C, the film removal rate (film dissolution rate, film cleaning rate) was 0.003 mZ, so it took 333 hours or more to remove the 1 μm thick resist film. It took a lot of time (Sample substrate 1-5). Next, when the ozone water temperature is 35 ° C, the film peeling rate is 0.04 mZ (approximately 25 minutes until removal) (sample substrate 1-4)), and when it is 50 ° C, 0.4 μmZ (removal) Until about 2 minutes and 30 seconds) (sample substrate 1-3). Furthermore, when the ozone water temperature was raised to 60 ° C, the film removal rate became 1.1 μmZ (approximately 55 seconds until removal), and it was confirmed that the removal time force was less than S1 minutes (sample Board 1 2)). When the temperature and water temperature were raised to 70 ° C, the film peeling rate was 1.9 mZ (approximately 32 seconds until removal) (sample substrate 1-1). From these facts, it was found that the sample substrate 1 is sufficiently practical by setting the ozone water temperature to 50 ° C or higher.

[0097] Next, referring to Table 6, the experimental results of the sample substrate 2 will be examined. When the ozone water temperature is 6 ° C, the membrane removal rate (membrane dissolution rate, membrane cleaning rate) is 0.025 mZ. As a result, it was found that it takes more than 40 hours to remove the 1 μm thick resist film (Sample Substrate 2-3). The reason why the removal time is significantly shorter than that of the sample substrate 1 under almost the same conditions may be due to the presence or absence of the inbra force. Next, when the ozone water temperature is 45 ° C, the film peeling rate is 1.85 / z mZ (approximately 32 seconds until removal) (sample substrate 2-2)). It was accelerated to (sample substrate 2-3) in 6 mZ (approximately 16 seconds until removal). From these facts, it was found that the sample substrate 2 was sufficiently practical when the ozone water temperature was set to 45 ° C or higher. However, for sample substrate 2, for example, if the removal time is set to around 1 minute using the same ozone water, even if it is 45 ° C or less (for example, 35 ° C or more), it is sufficiently practical. I can guess there is.

[0098] The peeling rate of Comparative Substrate 2-6 was 0.002 1117 minutes (7 ° 0, while ozone was cleaned by high-concentration ozone water of 130 mgZL, ozone concentration of 27% ZL (27 mgZL). The separation rate was 10 times (0.025 + 0.002) or more compared to the peeling rate of sample substrate 2-3 cleaned with water W. Similarly, the peeling rate of comparative substrate 2-5 was changed to the sample substrate. Compared with the peel rate of 2-2, there is almost three times the difference (1.85 ÷ 0.65). Compared with the peel rate of sample substrate 2-1, the peel rate of comparative substrate 2-4 From the results, it is very important to reduce the particle size of ozone bubbles in order to increase the peeling speed. Furthermore, as a result of setting the ozone generation amount to 50 gZNm ³ , the dissolved ozone concentration was 29 to 27 mg / L (g / Nm ³ ) as shown in Table 5 and Table 6 as described above. Is However, by increasing the amount of ozone generated, it will be possible to clean more effectively by increasing the concentration of dissolved ozone in the ozone water W, which should be performed in this experiment. By changing the ozone generation amount to 200 gZNm ³ or 350 gZNm ³ , it is possible to achieve a dissolved ozone concentration of 130 mgZL or higher as shown in Table 6, and it is possible to achieve dissolved ozone over a range without damaging the substrate. This is because the higher the concentration, the faster the peeling speed.

[0099] As described above, when the silicon wafer substrate (semiconductor substrate) is cleaned using ozone water having a particle size R force O <R≤50 nm of the contained ozone bubbles, particularly by increasing the temperature of the ozone water. It was found that the photoresist film can be efficiently peeled off.

[0100] (Inference based on experimental results) The inventors speculate as follows about the causal relationship that the semiconductor substrate cleaning using ozone water with the particle size R force SO <R≤50 nm of the ozone bubbles contained is extremely suitable. This will be described with reference to FIGS. The particle size D of the ozone bubbles Lz shown in Fig. 12 is, for example, 500 μm. Ozone bubbles! Z particle size For example, 700 μm. Ozone bubbles! Since z has a larger volume than the ozone bubble L, the buoyancy received from the ozone water W is larger by that amount, so it rises toward the water surface. For this reason, ozone bubbles! Z are less useful for cleaning because they are less likely to come into contact with resist HR. On the other hand, the ozone bubble L z has a relatively small buoyancy due to the ozone water W force, so it floats in the ozone water W.

Therefore, there is a possibility of contact with the resist HR. The ozone bubbles in contact with the resist HR react with ozone in the Lz and contribute to the peeling of the resist film R.

The particle size R of the ozone bubbles Sz shown in Fig. 13 is 50 nm or less, most of which is 30 nm or less, and the buoyancy received from the ozone water W is extremely small. For this reason, there are almost no ozone bubbles Sz trying to rise to the surface of the ozone water W. For this reason, there are much more opportunities for contact with the resist HR compared to the ozone bubbles Lz shown in FIG. Also, since the normal ozone bubble is almost spherical, contact with the resist HR is close to point contact even if there is deformation due to contact. Therefore, there is no big difference between the contact area of the ozone bubbles Lz in contact with the resist film R and the contact area of the ozone bubbles Sz! /. As can be readily understood by comparing FIG. 12 and FIG. 13, if there is no significant difference in the contact area with the resist HR, the ozone bubble Sz shown in FIG. 13 is more simultaneous than the ozone bubble Sz shown in FIG. As the number of possible bubbles is large, the total contact area is wide. As shown in FIG. 14, the resist HR also has a recess G having a width d of about 60 nm, for example. In order to react with the sidewall of the resist film R in the recess G, It is necessary to allow ozone bubbles to enter G. The ozone bubbles that can pass through the width d of about 60 ηm are not the ozone bubbles Lz shown in FIG. 12 but the ozone bubbles Sz shown in FIG. In this way, ozone bubbles with a particle size of 50 nm or less contained in the ozone water W can react with the recesses of the resist film R in contact with the side walls of the projections, so the cleaning effect is remarkably high. .

Claims

The scope of the claims

[1] A substrate cleaning method in which a substrate is cleaned using ozone water that has been produced without addition by a gas-liquid mixing method,

The particle size R of the ozone bubbles contained in the ozone water is 0 <R ≤ 50 nm

And a substrate cleaning method.

[2] Ozone water generation step of generating ozone water with a particle size R of the contained ozone bubbles 0 <R ≤ 50 nm by a gas-liquid mixing method that does not include the added waste,

The ozone water generation step includes an ozone water cleaning step of cleaning the substrate using the generated ozone water.

And a substrate cleaning method.

[3] The raw water used in the gas-liquid mixing method is pure water or ultrapure water.

3. The substrate cleaning method according to claim 1, wherein the substrate is cleaned.

[4] In the ozone water generating step, raw water is passed through a bench lily pipe having a small path, ozone is supplied to the bench lily pipe, and a magnetic force is applied to at least the small path of the bench lily pipe.

4. The substrate cleaning method according to claim 2, wherein the substrate is cleaned.

[5] Magnetic force of the magnet is set to 1000-30000 gauss

5. The substrate cleaning method according to claim 4, wherein:

[6] The ozone water that has passed through the bench lily pipe is circulated and re-passed through the venturi pipe at least once while supplying ozone.

6. The substrate cleaning method according to claim 5, wherein:

[7] Temporarily store the circulated ozone water in a storage tank

The substrate cleaning method according to claim 6.

[8] The ozone water stored in the storage tank is maintained in the range of 0 to 15 ° C.

The substrate cleaning method according to claim 7.

[9] Promote ozone dissolution by storing ozone water in dissolution accelerating tank

9. The substrate cleaning method according to claim 2, wherein the substrate is cleaned.

[10] The ozone degassed from the ozone water stored in the dissolution accelerating tank or the storage tank Discharge outside the dissolution accelerating tank

The substrate cleaning method according to claim 9.

[11] During cleaning with ozone water, the object to be cleaned formed on or adhered to the substrate surface or the substrate surface has energy to generate radicals by decomposing ozone in the ozone water. And irradiating light of a wavelength having energy lower than the binding energy of the constituent material of the substrate or the formation on the substrate surface.

The substrate cleaning method according to claim 1, wherein

[12] Flowing ozone water against the substrate

The substrate cleaning method according to claim 1, wherein

[13] Heat ozone water before substrate contact

The substrate cleaning method according to any one of claims 1 to 12, wherein the substrate is cleaned.

[14] Giving ultrasonic energy to ozone water before substrate contact

[15] The substrate is a semiconductor substrate

15. The substrate cleaning method according to claim 1, wherein the substrate cleaning method is performed.

[16] The substrate is a liquid crystal substrate

[17] a cleaning tank for cleaning the substrate;

And an ozone water generator for supplying ozone water to the cleaning tank,

The ozone water generator includes a bench lily pipe having a small path and an ozone supply apparatus for supplying ozone to pure water or ultrapure water passing through the small path of the bench lily pipe. ,

The bench lily tube is provided with pure water that has been supplied with ozone or a magnet that applies ultra-pure magnetic force, so that it can be configured to generate ozone water in which the particle size R of the ozone bubbles contained is 0 <R ≤ 50 nm. is there

A substrate cleaning apparatus.

[18] The magnet is constituted by a magnetic circuit including one magnet piece and the other magnet piece. The

The one magnet piece and the other magnet piece are opposed to each other across the bench lily tube.

18. The substrate cleaning apparatus according to claim 17, wherein:

[19] The magnetic force of the magnet is set to 1000-30000 gauss

The substrate cleaning apparatus according to claim 17 or 18, wherein

[20] The circulation structure for circulating ozone water that has passed through the bench lily pipe and passing the bench lily pipe again is further configured.

20. The substrate cleaning apparatus according to any one of claims 17 to 19, wherein

[21] A storage tank is provided in the middle of the circulation structure to temporarily store the ozone water to be circulated.

21. The substrate cleaning apparatus according to claim 20, wherein:

[22] A temperature holding structure for holding the ozone water in the storage tank in a range of 0 to 15 ° C is provided.

The substrate cleaning apparatus according to claim 21, wherein

[23] A heating means for heating the ozone water supplied to the cleaning tank or supplied to the cleaning tank is provided.

The substrate cleaning apparatus according to any one of claims 17 to 22, wherein

[24] The cleaning tank has energy for generating radicals by decomposing ozone in the ozone water on the substrate surface or an object to be cleaned formed on or attached to the substrate surface. In addition, a light source for irradiating light having a wavelength lower than the binding energy of the constituent material of the substrate or the formed material on the substrate surface is also provided.

24. The substrate cleaning apparatus according to any one of claims 17 to 23.

[25] An ultrasonic vibration mechanism is installed to give ultrasonic energy to the ozone water before substrate contact

The substrate cleaning apparatus according to any one of claims 17 to 24, wherein:

[26] The substrate is a semiconductor substrate The substrate cleaning apparatus according to any one of claims 17 to 25, wherein The substrate is a liquid crystal substrate

The substrate cleaning apparatus according to any one of claims 17 to 25, wherein