JP2000015196A - Washing of substrate and device for washing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a good washing effect while using a washing soln. having a low concn. by forming the washing soln. by mixing hydrogen peroxide, an alkaline soln. or acidic soln. and pure water, forming an irradiated washing soln. by irradiating the washing soln. with ultraviolet rays and washing a substrate with the irradiated washing soln. just after irradiation. SOLUTION: Liquid chemicals stored respectively in tanks 2A-2D as liquid chemical tanks are supplied to a mixing tank 3 while controlling the timing and the quantities with respective valve A-D, and liquid chemicals and washing agents are uniformly mixed. Then the mixed washing soln. is supplied to an irradiating means 5 with a supply pump 4 and irradiated with the ultraviolet rays from a light source while the soln. passes through a washing soln. irradiating pipe 5b. Subsequently, the irradiated washing soln. is supplied to a spray means 7, and the soln. is sprayed on the both front and back surfaces of a substrate 10 from both upper and lower spray nozzles 7a, 7b. At this time, respective flow rates of the ultraviolet rays washing soln. and the irradiated washing soln. are controlled respectively via valves F and G by an operation controlling means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning a substrate, and more particularly to a method and an apparatus for cleaning a substrate including a step of irradiating ultraviolet rays.

[0002]

2. Description of the Related Art Generally, a semiconductor substrate or a liquid crystal substrate is cleaned by (1) removal of organic substances on a surface, (2) removal of a natural oxide film, (3) removal of heavy metals on a surface, and (4) removal of fine particles. For the purpose of manufacturing semiconductors.

When one of such cleaning steps is insufficient, contamination remaining on a substrate or the like causes a defective product such as a semiconductor. Therefore, the substrate must be completely cleaned.

However, when a long time is required for complete cleaning, the production efficiency is reduced, and when a large amount of cleaning liquid (chemicals) is used, labor and cost are spent for treating chemicals discarded after cleaning. It will be.

[0005] Therefore, it is important to reduce the time required for the substrate cleaning process and to reduce the consumption of the cleaning solution used.

A method for cleaning a substrate is disclosed in Japanese Patent Laid-Open No. Hei 6-2877.
No. 84 discloses a method of irradiating a hydrogen peroxide solution with ultraviolet rays, or cleaning the surface with a mixture of a vapor of the hydrogen peroxide solution and ozone.

[0007]

However, the concentration of the cleaning liquid which can provide a standard cleaning effect in the conventionally used cleaning liquid is relatively high. As the size of the substrate or the silicon wafer is increased and the aspect ratio is increased, the amount of the cleaning liquid used and the amount of the waste liquid are further increased, and the labor and cost spent on the waste liquid purification processing become a heavy burden.

Although throughput is not as good as batch processing (processing a plurality of substrates at once using a cleaning tank), single wafer processing (each substrate is performed one by one) Cleaning treatment).

When the conventional cleaning liquid containing hydrogen peroxide is heated to 60 ° C. or higher in order to increase its oxidizing power, heating equipment is required, energy consumption is large, and the cleaning effect is temporarily reduced. Although increasing, the deterioration with time is remarkable.

Although the use of only hydrogen peroxide solution is effective in removing organic substances, it cannot completely remove particle contamination and metal contamination which are important in semiconductor production.

As described above, in the method of cleaning a substrate including the step of irradiating ultraviolet rays, the consumption of a chemical solution such as an aqueous solution of hydrogen peroxide and an acidic solution or an alkaline solution is suppressed using a low-concentration cleaning solution, and It has been difficult to provide a cleaning method in which the cleaning is performed in a state where the activity of the hydrogen water is enhanced and a good cleaning effect is obtained.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to improve the disadvantages of the prior art by mixing a hydrogen peroxide solution with an alkaline solution or an acidic solution and pure water to form a cleaning solution, and irradiating the mixed cleaning solution with ultraviolet rays. A method for cleaning a substrate, comprising a step of cleaning the substrate with an irradiation cleaning liquid immediately after the irradiation as an irradiation cleaning liquid, whereby a cleaning effect having a similar or higher cleaning effect can be obtained while using a cleaning liquid having a lower concentration than before. It is an object to provide a cleaning device.

[0013] Further, since an alkaline solution or an acidic solution is added to the hydrogen peroxide solution and irradiated with ultraviolet rays, not only organic matter contamination but also particle contamination and metal contamination are sufficiently removed, thereby simplifying the cleaning process and using a chemical solution. Can be reduced, and a simple cleaning method and a substrate cleaning apparatus can be provided.

Further, since the amount of the cleaning agent used can be suppressed while maintaining the cleaning effect, the labor and cost for processing and recovering the waste liquid can be reduced, and a substrate cleaning method and a substrate cleaning apparatus which are economically efficient. Can also be provided.

[Means for Solving the Problems]

In order to achieve the above object, according to the first aspect of the present invention, in a substrate cleaning step, a hydrogen peroxide solution, an alkaline solution and pure water are mixed to form a cleaning liquid, and the mixed cleaning liquid is irradiated with ultraviolet rays. And cleaning the substrate with the irradiation cleaning liquid immediately after the irradiation.

The hydrogen peroxide solution is in an ultraviolet region (particularly, 350 nm
When the hydrogen peroxide solution is irradiated with ultraviolet light having a large absorption in the wavelength region of the following), it reacts as follows to generate a hydroxyl radical. ^{_{2H 2 O 2 → OH - +}} · OH + HO 2 · + H + The hydroxamates Resid radicals also themselves for having oxidizing power, cleaning capacity is synergistically improved.

The aqueous hydrogen peroxide is an oxidizing agent, and is particularly alkaline and has a remarkable function. By utilizing such a property, a higher detergency than in the case of performing ultraviolet irradiation with hydrogen peroxide alone can be obtained, and a detergency equivalent to or higher than the conventional one can be obtained even with a low concentration of hydrogen peroxide. be able to.

The cleaning liquid of the present invention effectively works not only for organic substance contamination but also for particle contamination and metal contamination. Particularly, in the case of a cleaning liquid in which an alkaline solution and a hydrogen peroxide solution are mixed, the particles can be removed well. Do.

According to a second aspect of the present invention, in the substrate cleaning step, a hydrogen peroxide solution, an alkaline solution and pure water are mixed to form a cleaning liquid, and the mixed cleaning liquid is irradiated with ultraviolet rays to form an irradiation cleaning liquid. A step of injecting the irradiation cleaning liquid onto the substrate immediately after the irradiation is provided.

As described above, a cleaning solution obtained by irradiating a mixture of hydrogen peroxide, an alkaline solution, and pure water with ultraviolet rays is desirably used immediately because its activity is easily reduced.
For this reason, the substrate can be washed while maintaining its activity after the irradiation with the ultraviolet rays. Therefore, the irradiation cleaning liquid was sprayed onto the substrate immediately after the irradiation with the ultraviolet rays.

In some cases, single-wafer processing is more suitable than badge processing because of the increase in the size of substrates such as wafers and the increase in the aspect ratio. According to the present invention, it is possible to reduce the consumption of the cleaning liquid and to perform cleaning of each sheet while covering the defects of the single wafer type.

Similarly, the invention according to claim 3 includes a step of immersing the substrate in the same irradiation cleaning liquid in the cleaning step. For immersion of the substrate, the substrate is placed in a cleaning tank filled with an irradiation cleaning solution and cleaned. At this time, an ultrasonic wave may be applied.

According to a fourth aspect of the present invention, in the step of cleaning the substrate, an aqueous solution of hydrogen peroxide, an alkaline solution and pure water are mixed to form a cleaning liquid, and the cleaning liquid is sprayed on the substrate and, at the same time, the substrate is irradiated with ultraviolet rays. The step of performing Since the cleaning liquid of the present invention has a high activation rate after being irradiated with ultraviolet rays, the same cleaning effect can be obtained by irradiating ultraviolet rays while spraying the cleaning liquid onto the substrate.

According to the above-described processing, the cleaning can be performed with a low-concentration cleaning liquid in the same manner as in the second aspect of the invention, and the processing time required for cleaning can be reduced even in the processing of one substrate.

According to a fifth aspect of the present invention, in the substrate cleaning step, a hydrogen peroxide solution, an alkaline solution, and pure water are mixed to form a cleaning solution, and the substrate is immersed in the mixed cleaning solution. Irradiating the substrate with ultraviolet light.

A plurality of substrates are immersed in a cleaning tank filled with a cleaning liquid as in the third aspect of the present invention, and ultraviolet rays are irradiated in that state. The ultraviolet irradiation direction is appropriately set according to the direction of the substrate immersed so that the ultraviolet light is not blocked by the substrate,
The entire cleaning solution that contacts each substrate must be activated.

According to the sixth aspect of the present invention, the first to fifth aspects are provided.
The alkaline solution in each of the inventions was an ammonia solution.

According to the seventh aspect of the present invention, the concentration of ammonia in the cleaning solution is 1/1000% at which the cleaning effect is exhibited.
Not less than 2% and the concentration of the hydrogen peroxide solution is 1/5000.
% Or more and 2% or less.

The cleaning solution conventionally used has an ammonia concentration of 1% to 2% and a hydrogen peroxide concentration of 2% to 4%. Therefore, the concentration of the chemical solution used while maintaining the conventional cleaning effect is maintained. Can be greatly reduced. The combination of ammonia and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

The alkaline solution is not limited to an ammonia solution, but is preferably volatile because it must not remain after cleaning and adversely affect semiconductors and the like.

According to an eighth aspect of the present invention, in the substrate cleaning step, a hydrogen peroxide solution, an acidic solution and pure water are mixed to form a cleaning liquid, and the mixed cleaning liquid is irradiated with ultraviolet rays to form an irradiation cleaning liquid. A step of cleaning the substrate with an irradiation cleaning liquid immediately after the irradiation is provided.

As described above, the aqueous hydrogen peroxide has a large absorption in the ultraviolet region (especially, 350 nm or less). When the aqueous hydrogen peroxide is irradiated with ultraviolet light, it reacts as follows to generate hydroxyl radicals. ^{_{2H 2 O 2 → OH - +}} · OH + HO 2 · + H + Further, the presence of chloride ions react as follows _{^{Cl - + H 2 O 2 →}} - OCl + H 2 O H 2 O 2 ^{+ HOCl (- OCl) → 1} O 2 + H 2 O + HCl (Cl -) superoxide (singlet oxygen) occurs. Since the superoxide itself has an oxidizing power, the cleaning ability is synergistically improved.

By utilizing such properties, a higher detergency can be obtained than in the case where ultraviolet irradiation is performed using only a hydrogen peroxide solution, and even with a low concentration of a hydrogen peroxide solution, a cleaning effect equal to or higher than that of the conventional method can be obtained. You can gain power.

The cleaning liquid of the present invention effectively works not only for organic substance contamination, but also for particle contamination and metal contamination. In the case of a cleaning liquid in which an acidic solution and a hydrogen peroxide solution are mixed, particularly good removal of metal contamination is achieved. To do.

According to the ninth aspect of the present invention, in the cleaning step of the substrate, a hydrogen peroxide solution, an acidic solution and pure water are mixed to form a cleaning liquid, and the mixed cleaning liquid is irradiated with ultraviolet rays to form an irradiation cleaning liquid. A step of injecting the irradiation cleaning liquid onto the substrate immediately after the irradiation is provided.

As described above, the cleaning solution obtained by irradiating the mixture of the hydrogen peroxide solution, the acidic solution and the pure water with ultraviolet rays is desirably used immediately since its activity is easily deteriorated. Therefore, in order to maintain the activity immediately after the ultraviolet irradiation, the irradiation cleaning liquid was sprayed on the substrate immediately after the ultraviolet irradiation.

In some cases, single-wafer processing is more suitable than badge processing because of the increase in the size of substrates such as wafers and the increase in the aspect ratio. According to the present invention, it is possible to reduce the consumption of the cleaning liquid and to perform cleaning of each sheet while covering the defects of the single wafer type.

Similarly, the invention according to claim 10 includes a step of immersing the substrate in the same irradiation cleaning liquid in the cleaning step. For immersion of the substrate, the substrate is placed in a cleaning tank filled with an irradiation cleaning solution and cleaned. At this time, an ultrasonic wave may be applied.

According to the eleventh aspect of the present invention, in the step of cleaning the substrate, a hydrogen peroxide solution, an acidic solution and pure water are mixed to form a cleaning liquid, and the cleaning liquid is sprayed on the substrate at the same time.
A step of irradiating the substrate with ultraviolet light was provided. Since the cleaning liquid of the present invention has a high activation rate after being irradiated with ultraviolet rays, the same cleaning effect can be obtained by irradiating ultraviolet rays while spraying the cleaning liquid onto the substrate.

According to the above-described processing, it is possible to perform cleaning with a low-concentration cleaning liquid in the same manner as in the second aspect of the present invention, and it is possible to reduce the processing time required for cleaning even in the processing of one substrate at a time.

According to a twelfth aspect of the present invention, in the substrate cleaning step, a hydrogen peroxide solution, an acidic solution and pure water are mixed to form a cleaning liquid, and the substrate is immersed in the mixed cleaning liquid, and Irradiating the substrate with ultraviolet light.

As in the tenth aspect, a plurality of substrates are immersed in a cleaning tank filled with a cleaning liquid and irradiated with ultraviolet rays in that state. The ultraviolet irradiation direction is appropriately set depending on the direction of the substrate to be immersed so that the ultraviolet light is not blocked by the substrate, and the entire cleaning liquid that contacts each substrate must be activated.

In the inventions of claims 13 and 14, the acidic solution in each of the inventions of claims 7 to 11 is a hydrochloric acid solution, and in the inventions of claims 15 and 16, it is a hydrofluoric acid solution, and in the inventions of claims 17 and 18, In the invention, a sulfuric acid solution was used.

When a hydrochloric acid solution was used, the concentration of hydrochloric acid in the cleaning solution was set to 1/100% to 6%, and the concentration of hydrogen peroxide was set to 1/5000% to 2%.

Here, the cleaning solution conventionally used has a hydrochloric acid concentration of 4% to 6% and a hydrogen peroxide concentration of 4% to 6%.
Therefore, the concentration of the chemical used can be greatly reduced while maintaining the conventional cleaning effect. The combination of hydrochloric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a hydrofluoric acid solution was used, the concentration of the hydrofluoric acid solution in the cleaning solution was 1/500% or more and 1% or less, and hydrogen peroxide was 1/5000% or more and 2% or less.

Here, the cleaning solution conventionally used has a hydrofluoric acid concentration of 0.1% to 1% and a hydrogen peroxide concentration of 0.1%.
% To 2%, the concentration of the chemical used can be greatly reduced while maintaining the conventional cleaning effect.
The combination of hydrofluoric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a sulfuric acid solution was used, the concentration of the sulfuric acid solution in the cleaning solution was 5% or more and 90% or less, and the concentration of the hydrogen peroxide solution was 1/5000% or more and 2% or less.

The cleaning solution used heretofore has a sulfuric acid concentration of 80% to 90% and a hydrogen peroxide concentration of 10% to 20%. Can be greatly reduced. The combination of sulfuric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

These are mixed with a hydrogen peroxide solution and irradiated with ultraviolet rays, whereby the cleaning ability is further improved, and the substrate can be sufficiently cleaned even with such a thin solution.

According to the nineteenth aspect of the present invention, in the cleaning apparatus for cleaning a substrate, a plurality of chemical tanks for storing a plurality of types of chemicals including an alkaline solution or an acidic solution, and a predetermined amount of the chemical used are stored in each of the chemical tanks. A chemical mixing tank for injecting and mixing a cleaning liquid, irradiating means for irradiating the cleaning liquid with ultraviolet light, and irradiating means for irradiating the substrate with an irradiation cleaning liquid irradiated with ultraviolet light by the irradiation means to perform cleaning. ing.

The irradiating means irradiates ultraviolet light, and a light source arranged in a plane and a cleaning liquid irradiating tube are arranged so as to form a surface facing the light source.

Each component will be described.

The chemical solution tank is prepared according to the number of types of chemical solution to be used, such as an alkaline solution, an acidic solution, a hydrogen peroxide solution, and a pure water solution.

These supply a chemical solution to the mixing tank through a tube. The supply amount is adjusted by the valve of each chemical tank,
Thus, the concentration of the chemical contained in the cleaning liquid is determined. As the valve, an electromagnetic valve or the like that opens and closes a switch by electromagnetic force can be adopted.

In the chemical tank, a predetermined amount of chemical is injected, and then the cleaning agent is uniformly mixed.

The irradiating means has a light source and a cleaning liquid irradiating tube. This light source has an absorption band of hydrogen peroxide water of 300.
It is preferable that the irradiation be performed using ultraviolet light of 150 nm to 320 nm. High pressure mercury lamp,
A low pressure mercury lamp can be used. It is also possible to use a xenon lamp having an emission peak at around 250 nm. Preferably, it is desirable to use a large-capacity low-pressure mercury lamp capable of easily obtaining an irradiation intensity of 200 W / cm ² or more. In order to sufficiently irradiate the cleaning liquid, the light sources are desirably arranged in a plane.

The cleaning liquid irradiating tube was arranged so as to form a surface facing the light source. The cleaning liquid irradiation tube is intended to sufficiently expose the cleaning liquid to ultraviolet rays. This cleaning liquid irradiation tube is preferably made of quartz or the like so that ultraviolet light can be sufficiently transmitted.

In order to receive sufficient ultraviolet irradiation, it is desirable that the light source be arranged in a plane so as to face the above light source. The term “planar arrangement” means that a plurality of tubes may be arranged in parallel, but one washing liquid irradiation tube is folded back and forth to meander the tubes to increase the surface area. This is in order to sufficiently receive the ultraviolet irradiation.

A reflecting means such as a mirror is provided on the back surface of the cleaning liquid irradiation tube facing the light source so that the irradiation is sufficiently performed.
Thereby, the transmitted ultraviolet light can be reused.

The irradiation amount of the ultraviolet light varies depending on the length, thickness, cross-section, and the like of the cleaning liquid irradiation tube, and is determined according to the object to be cleaned.

Since the irradiation time of the ultraviolet light changes depending on the amount of the cleaning liquid sent to the cleaning liquid irradiation tube, the flow rate of the cleaning liquid sent to the cleaning liquid irradiation tube must be adjusted according to the state of the object to be cleaned. The adjustment of the flow rate can be performed by a valve.

The injection means is a means for receiving the pressure of a supply pump or the like and spraying the irradiation cleaning liquid or the cleaning liquid evenly on the substrate. It may be a shower-like one or a spray-like one from a nozzle. The jetting means is provided at a position opposed to both sides to jet to the front and back surfaces of the substrate.

The jetting of the cleaning liquid by the jetting means can be performed before or after the ultraviolet irradiation treatment. That is, the irradiation cleaning liquid that has been irradiated and activated with ultraviolet rays may be sprayed on the substrate, and the cleaning liquid that has not been irradiated with ultraviolet rays is sprayed onto the substrate, and then the substrate sprayed with the cleaning liquid is irradiated with ultraviolet light. It is also possible.

When using a cleaning liquid which has already been irradiated with ultraviolet rays, the distance between the injection means and the irradiation means must be reduced. This is because the cleaning liquid activated by irradiation with ultraviolet rays deteriorates quickly and is preferably used for cleaning as soon as it is irradiated.

Therefore, the structure is such that the flow of the cleaning liquid is not interrupted. This is for use before the activated detergency decreases.

Further, a circulating means for recovering and reusing the cleaning liquid used for cleaning may be provided. This is because the cleaning ability is regenerated by removing dirt from the collected cleaning liquid and irradiating ultraviolet rays again, and the cleaning liquid can be reused.

With this configuration, a predetermined type of chemical solution is supplied from the plurality of chemical solution tanks to the mixing tank. This amount is controlled by each valve of each chemical solution tank. The supplied chemicals are uniformly mixed in a mixing tank to become a cleaning liquid. The flow rate and pressure of the cleaning liquid are adjusted by a valve and a supply pump provided therewith and sent to the irradiation means.

The irradiating means circulates through a tube made of a material which transmits ultraviolet light such as quartz so as to be sufficiently irradiated by a light source which emits ultraviolet light such as a large-capacity low-pressure mercury lamp. In order to efficiently perform the ultraviolet irradiation, the light sources are arranged in a plane, and the cleaning liquid irradiation tubes are arranged in parallel so as to form a surface facing the planar light source, or folded back and forth to meander.

The cleaning liquid is activated while passing through the cleaning liquid irradiation tube. The amount of the irradiated ultraviolet rays is adjusted by the flow rate and the flow rate of the cleaning liquid. Specifically, the flow rate and the flow rate are controlled by a predetermined valve controlled by the operation control means provided in combination.

The cleaning of the substrate can be performed by spraying the irradiation cleaning liquid, which has been irradiated with the ultraviolet rays, uniformly from the front and back surfaces of the substrate to be cleaned from the spray nozzle into the shower.
It may be carried out by immersing in a washing tank. However, it is not allowed to stay for a long time after the irradiation with the cleaning liquid, and the cleaning liquid is used for cleaning immediately after the irradiation. This is because the detergency increased by the irradiation of ultraviolet rays decreases with time.

The irradiation of ultraviolet rays is performed with a cleaning liquid (not irradiated).
After spraying the substrate on the substrate, and then immersing the substrate in a cleaning liquid (not irradiated).

According to the cleaning method and the cleaning apparatus, the substrate can be cleaned with a chemical solution having a lower concentration than the conventional one with the same or higher effect as the conventional one. Accordingly, in the substrate cleaning step, the consumption of the chemical solution used can be suppressed, and at the same time, the amount of waste liquid can be suppressed, and the cost conventionally required for the cleaning step can be greatly reduced.

[0074]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart showing one embodiment of the present invention.

In the cleaning process of the substrate 10, Step 1
If necessary in (S1), preprocessing is performed. The cleaning is performed if necessary with an organic solvent or the like.

In step 2 (S2), a hydrogen peroxide solution, an alkaline solution and pure water, or a hydrogen peroxide solution, an acidic solution and pure water are mixed. This becomes the cleaning liquid.

In step 3 (S3), the cleaning liquid is irradiated with ultraviolet rays. This becomes the irradiation cleaning liquid.

In step 4 (S4), the irradiation cleaning liquid is sprayed on the substrate 10, or the substrate 10 is immersed in the irradiation cleaning liquid.

Post-processing is performed if necessary in step 5 (S5). A treatment such as rinsing is performed after the resist is stripped with sulfuric acid and hydrogen peroxide.

The method of cleaning the substrate 10 of this embodiment includes such steps, and particularly includes the characteristic steps of S2, S3, and S4.

The contents of each step will be described. Step 2
The hydrogen peroxide solution and the alkaline solution or the acidic solution and the water in (S2) are mixed at a predetermined ratio. The ratio is arbitrarily determined depending on the type and structure of the substrate 10 to be cleaned.

In step 3 (S3), ultraviolet light is applied to activate the cleaning liquid. Hydrogen peroxide has a large absorption in an ultraviolet region (especially 350 nm or less), and when ultraviolet light is irradiated on the hydrogen peroxide, it reacts as follows to generate hydroxyl radicals. ^{_{2H 2 O 2 → OH - +}} · OH + HO 2 · + H + The hydroxamates Resid radical, since the itself has an oxidizing power, cleaning capacity is improved.

Aqueous hydrogen peroxide is an oxidizing agent, particularly alkaline, and its function is remarkable. By utilizing such a property, a higher detergency can be obtained than when ultraviolet irradiation is performed using only hydrogen peroxide solution, and a detergency equivalent to the conventional one can be obtained even with a low concentration of hydrogen peroxide solution. .

The cleaning liquid of the present invention effectively works not only for organic substance contamination but also for particle contamination and metal contamination. Particularly, in the case of a cleaning liquid in which an alkaline solution and a hydrogen peroxide solution are mixed, the particles can be removed well. .

[0085] In the presence of chloride ions react as follows ^{_{Cl - + H 2 O 2 →}} - OCl + H 2 O H 2 O 2 + HOCl (- OCl) → 1 O 2 + H 2 O + HCl (Cl ⁻ ) Superoxide (singlet oxygen) is generated. Since the superoxide itself has oxidizing power, the cleaning ability is improved.

By utilizing such a property, even when an acidic solution is added, a higher detergency can be obtained than when ultraviolet irradiation is performed using only a hydrogen peroxide solution. The same detergency can be obtained.

The cleaning liquid of the present invention effectively works not only for organic substance contamination but also for particle contamination and metal contamination. Particularly, in the case of a cleaning liquid in which an acidic solution and a hydrogen peroxide solution are mixed, good removal of metal contamination is achieved. To do.

In step 4, the activated irradiation cleaning liquid was sprayed on the substrate 10 immediately after activation, or the substrate 10 was immersed in the irradiation cleaning liquid.

Since the activity of the irradiation cleaning liquid irradiated with ultraviolet rays is apt to decline, it is desirable to use it immediately. Therefore, the irradiation cleaning liquid was sprayed on the substrate 10 immediately after the ultraviolet irradiation in order to maintain the activity after the ultraviolet irradiation.

Further, step 3 and step 4 can be performed simultaneously. That is, a step of irradiating the substrate 10 with ultraviolet rays at the same time as injecting the cleaning liquid onto the substrate 10 was provided. Since the cleaning liquid of the present invention has a high activation rate after being irradiated with ultraviolet rays, the same cleaning effect can be obtained by irradiating the cleaning liquid to the substrate 10 with ultraviolet rays. By such a process, the processing time required for cleaning can be shortened even for a single substrate.

Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a flowchart showing another embodiment of the present invention.

In the cleaning process of the substrate 10, step 1
If necessary in 1 (S11), preprocessing is performed. The cleaning is performed if necessary with an organic solvent or the like.

In step 12 (S12), a hydrogen peroxide solution, an alkaline solution and pure water, or a hydrogen peroxide solution, an acidic solution and pure water are mixed. This becomes the cleaning liquid.

In step 13 (S13), the cleaning liquid is sprayed on the substrate 10, or the substrate 10 is immersed in the cleaning liquid.

In step 14 (S14), in this state (the state in which the cleaning liquid is sprayed and the state in which the cleaning liquid is immersed), the substrate 1
0 is irradiated with ultraviolet rays.

If necessary in step 15 (S15), post-processing is performed. A treatment such as rinsing is performed after the resist is stripped with sulfuric acid and hydrogen peroxide.

The method of cleaning the substrate 10 according to the present embodiment includes such steps, and particularly includes the characteristic steps of S13 and S14.

Unlike the above-described embodiment, the cleaning liquid is first sprayed on the substrate 10 or the substrate 10 is immersed in the cleaning liquid. Then, in a state where the cleaning liquid is applied to the substrate 10 (a state where the cleaning liquid is sprayed, a state where the cleaning liquid is immersed in the cleaning liquid),
0 is irradiated with ultraviolet rays. The same means can be used for other common light sources. However, when irradiating with ultraviolet light in a state of being immersed, the substrate 10
And the incident direction of ultraviolet rays are appropriately determined.

Since the activity of the irradiation cleaning liquid after the irradiation of the ultraviolet light is easily deteriorated, the ultraviolet light is irradiated after the cleaning liquid contacts the substrate 10 (while the cleaning liquid is in contact with the substrate 10). Since the cleaning liquid is activated while being in contact with the substrate 10, the nascent radical can be sufficiently utilized.

The same effect can be obtained by irradiating the substrate 10 with ultraviolet rays at the same time as spraying the cleaning liquid onto the substrate 10.

By such processing, the processing time required for cleaning can be shortened even in the processing of one substrate at a time.

Next, the chemicals used in the above two embodiments will be described. Here, an alkaline solution and an acidic solution are used. Ammonia solution was mainly used for the alkaline solution. The alkaline solution is not limited to an ammonia solution, but is preferably a volatile one because it should not remain after cleaning and adversely affect a semiconductor or the like. On the other hand, as the acidic solution, a hydrochloric acid solution, a hydrofluoric acid solution, and a sulfuric acid solution were used as typical examples.

The concentration of ammonia in the cleaning solution is 1 /
1000% or more and 2% or less, and the concentration of the hydrogen peroxide solution is 1
/ 5000% or more and 2% or less. The cleaning solution used conventionally has an ammonia concentration of 1% to 2% and a hydrogen peroxide concentration of 2% to 4%. Therefore, it is necessary to greatly reduce the concentration of the chemical solution used while maintaining the conventional cleaning effect. Can be. The combination of ammonia and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

The concentrations of hydrochloric acid solution, hydrofluoric acid solution and sulfuric acid solution used as the acidic solution are as follows.

When a hydrochloric acid solution was used, the concentration of hydrochloric acid in the cleaning solution was 1/100% to 6%, and the concentration of hydrogen peroxide was 1/5000% to 2%. The cleaning solution used conventionally has a hydrochloric acid concentration of 4% to 6% and a hydrogen peroxide concentration of 4% to 6%. Therefore, it is necessary to greatly reduce the concentration of the chemical solution used while maintaining the conventional cleaning effect. Can be. The combination of hydrochloric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a hydrofluoric acid solution was used, the concentration of the hydrofluoric acid solution in the cleaning solution was 1/500% or more and 1% or less, and the concentration of hydrogen peroxide was 1/5000% or more and 2% or less. Conventionally used cleaning solutions have a hydrofluoric acid concentration of 0.1% to 1%,
Since the concentration of hydrogen peroxide is 0.1% to 2%, it is possible to greatly reduce the concentration of the used chemical solution while maintaining the conventional cleaning effect. The combination of hydrofluoric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a sulfuric acid solution was used, the concentration of the sulfuric acid solution in the cleaning solution was 5% or more and 90% or less, and the concentration of the hydrogen peroxide solution was 1/5000% or more and 2% or less. Conventionally used cleaning solutions have a sulfuric acid concentration of 80% to 90% and a hydrogen peroxide concentration of 10% to 20%. Therefore, the concentration of the chemical solution used must be greatly reduced while maintaining the conventional cleaning effect. Can be. The combination of sulfuric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

These are mixed with a hydrogen peroxide solution and irradiated with ultraviolet rays, whereby the cleaning ability is further improved, and the substrate 10 can be sufficiently cleaned even with such a thin solution.

Next, the substrate cleaning apparatus 1 will be described with reference to FIGS. FIG. 3 shows a first embodiment of the substrate cleaning apparatus 1. The substrate cleaning apparatus 1 includes a plurality of chemical tanks 2 for storing a plurality of chemical liquids including an alkaline solution, an acidic solution, hydrogen peroxide solution, and pure water, and a predetermined amount of a chemical liquid to be used is injected from each chemical liquid tank 2. Chemical mixing tank 3 for mixing into cleaning liquid
Irradiating means 5 for irradiating the cleaning liquid with ultraviolet light;
And an injecting means 7 for injecting and cleaning.

The chemical solution tank 2 is prepared according to the number of types of chemical solution to be used, such as an alkaline solution, an acidic solution, a hydrogen peroxide solution, a pure water solution, etc., and includes tanks 2A, 2B, 2C, and 2D. It is prepared according to the number of kinds of medicines used. The supply timing and supply amount of these are controlled by valves A, B, C, and D provided in each tank 2A and the like. As the valve, an electromagnetic valve or the like that opens and closes a switch by electromagnetic force can be adopted.

The mixing tank 3 is a tank for mixing the chemicals supplied from each of the chemical liquid tanks 2. The mixing tank 3 mixes the cleaning agent uniformly after injecting a predetermined amount of the chemical solution. Since the amount of the chemical solution supplied to the mixing tank 3 is adjusted by a valve of each of the chemical tanks 2, a cleaning liquid is formed in the mixing tank 3 at a predetermined concentration of the chemical solution.

The cleaning liquid produced in the mixing tank 3 is sent to the irradiation means 5. The irradiation unit 5 has a light source 5a and a cleaning liquid irradiation tube 5b. Since the light source 5a has a wavelength of 300 nm or less, which is an absorption band of a hydrogen peroxide solution,
Irradiation using ultraviolet light of 0 nm is desirable. High-pressure mercury lamps and low-pressure mercury lamps can be used. Also 250
It is also possible to use a xenon lamp having an emission peak around nm. Preferably, the irradiation intensity is 200
It is desirable to use a large-capacity low-pressure mercury lamp capable of easily obtaining W / cm ² or more.

The light sources 5a are desirably arranged in a plane. This is for sufficiently irradiating the cleaning liquid. Therefore, the light sources 5a may be arranged in parallel so as not to interfere with each other.

The cleaning liquid irradiating tube 5b is arranged so as to form the light source 5a arranged in a plane as described above and a surface facing the light source 5a. Since the cleaning liquid irradiation tube 5b aims at sufficiently exposing the cleaning liquid to ultraviolet rays, it is preferable to use quartz or the like so that ultraviolet light can be sufficiently transmitted.

FIG. 5 shows the irradiation means 5 specifically arranged. 5 (a) is a perspective view thereof, and 5 (b) is a sectional view thereof.

To arrange in a plane shape, a plurality of tubes may be arranged in parallel, but in the example shown in FIG. 5, one washing liquid irradiation tube is folded back and forth to meander. This is because the surface area to be irradiated is increased so that ultraviolet irradiation can be sufficiently received. The cleaning liquid is activated by being irradiated with ultraviolet light while passing through the meandering quartz tube and is provided for cleaning.

A reflecting mirror 5c is provided on the back surface of the cleaning liquid irradiation tube 5b facing the light source so that the irradiation is sufficiently performed.
Thereby, the transmitted ultraviolet light can be reused.

The irradiation amount of the ultraviolet light varies depending on the shape such as the length, thickness, and cross section of the cleaning liquid irradiation tube 5b, and is determined according to the object to be cleaned.

Further, the irradiation time of the ultraviolet light changes depending on the amount of the cleaning liquid sent to the cleaning liquid irradiation tube 5b.
The flow rate of the cleaning liquid sent to the cleaning liquid irradiation tube must be adjusted according to the state of the object to be cleaned. The adjustment of the flow rate can be performed by the valve F. The amount of the cleaning liquid sent into the cleaning liquid irradiation tube 5b and the amount of the irradiation cleaning liquid sent out from the irradiation unit 5 can be related to the amount of the irradiation cleaning liquid sent out from the injection unit 7. Therefore, these amounts can be controlled according to the cleaning process of the substrate 10, and can be managed by the operation control unit 6.

The irradiation cleaning liquid which has been irradiated with the ultraviolet rays is sent to the injection means 7. The injection unit 7 is a unit that receives the pressure of the supply pump 4 or the like and evenly sprays the irradiation cleaning liquid or the cleaning liquid on the substrate 10. Shower-like things,
It may be sprayed in a mist form from a nozzle. The jetting means 7 is provided at a position opposed to both sides to jet to the front and back surfaces of the substrate 10.

The substrate cleaning apparatus 1 shown in FIG. 3 is provided with an injection nozzle 7a and an injection nozzle 7b, which are injection means 7 in the form of a nozzle. The ejection nozzle 7a ejects the irradiation cleaning liquid from the front surface of the substrate 10, and the ejection nozzle 7b ejects the irradiation cleaning liquid from the back surface of the substrate 10. With these two nozzles, the substrate 1
0 is sufficiently in contact with the washing solution.

The distance between the injection means 7 and the irradiation means 5 needs to be reduced. This is because the cleaning liquid activated by irradiation with ultraviolet rays deteriorates quickly and is preferably used for cleaning as soon as it is irradiated.

Therefore, it is configured such that the flow of the cleaning liquid does not stop. This is for use before the activated detergency decreases.

FIG. 4 shows a second embodiment having a different cleaning method. The substrate cleaning apparatus 1 of FIG. 4 cleans the substrate 10 by immersing the substrate 10 in a cleaning tank with an irradiation cleaning liquid. The substrates 10 are immersed together in the cleaning tank 4. Thus, the stain is removed by the activated cleaning liquid. This enables generally faster processing than washing one by one.

The cleaning liquid used for cleaning the substrate 10 passes through the drain 8 and removes contaminants through the waste liquid circulation filter 11. The regenerated cleaning liquid is returned to the mixing tank 3 and used again for cleaning.

A circulating means for recovering and reusing the used washing liquid can be provided. This allows
By removing dirt from the collected cleaning liquid and irradiating ultraviolet rays again, the cleaning ability is regenerated and can be reused.

FIG. 6 shows a third embodiment of the substrate cleaning apparatus 1, and FIG. 7 shows a fourth embodiment. The third and fourth embodiments are different from the first and second embodiments in that the ultraviolet irradiation is performed after the cleaning liquid is sprayed or immersed in the cleaning liquid.

The third embodiment has means for injecting a cleaning liquid onto the substrate 10 as in the first embodiment, and the fourth embodiment has a cleaning tank in which the substrate 10 is immersed, as in the second embodiment. Having.

That is, the cleaning liquid is sprayed on the substrate 10 first,
Alternatively, the substrate 10 is immersed in a cleaning liquid. Then, the substrate 10 is irradiated with ultraviolet rays in a state where the cleaning liquid is applied to the substrate (a state where the cleaning liquid is sprayed or a state where the cleaning liquid is immersed in the cleaning liquid).

In the case of irradiating the ultraviolet rays in the immersed state in the fourth embodiment, the arrangement of the substrates 10 and the incident direction of the ultraviolet rays are appropriately determined so that the ultraviolet rays are not blocked by the arranged substrates 10. .

Since the activity of the irradiation cleaning liquid after the irradiation of the ultraviolet light is easily deteriorated, the ultraviolet light is irradiated after the cleaning liquid contacts the substrate 10 (while the cleaning liquid is in contact with the substrate 10). Since the cleaning liquid is activated while being in contact with the substrate 10, the nascent radical can be sufficiently utilized.

The same effect can be obtained by simultaneously irradiating the substrate 10 with the cleaning liquid and irradiating the substrate 10 with ultraviolet rays.

With this configuration, a predetermined amount of a chemical liquid is supplied from the plurality of chemical liquid tanks 2 to the mixing tank 3 in a predetermined amount. This amount is controlled by each valve of each chemical solution tank 2. The supplied chemical liquid is made uniform in the mixing tank 3 and becomes a cleaning liquid. The flow rate and pressure of the cleaning liquid are adjusted by a valve E and a supply pump 4 attached thereto, and the cleaning liquid is sent to the irradiation means 5.

The irradiating means 5 circulates through a cleaning liquid irradiating tube 5b made of a material which transmits ultraviolet rays such as quartz so as to be sufficiently irradiated by a light source 5a which irradiates ultraviolet rays such as a large-capacity low-pressure mercury lamp. In order to efficiently perform the ultraviolet irradiation, the light sources 5a are arranged in a plane as shown in FIG. 5, and the cleaning liquid irradiation tubes 5b are arranged in parallel so as to constitute a surface facing the planar light source, or Turn back and forth in layers.

The cleaning liquid is activated while passing through the cleaning liquid irradiation tube 5b. The amount of the irradiated ultraviolet rays is adjusted by the flow rate and the flow rate of the cleaning liquid. In particular,
The flow rate and flow rate are controlled by a predetermined valve controlled by the operation control means 6 provided in parallel.

The cleaning of the substrate 10 is performed by applying the irradiation cleaning liquid which has been irradiated with ultraviolet rays as in the first or third embodiment to the spray nozzle 7.
a and 7b, even when the substrate 10 to be cleaned is sprayed uniformly from the front and back surfaces in the form of a shower,
Alternatively, as shown in 4, it may be carried out by immersing in a washing tank.

Irradiation with ultraviolet rays may be performed after the cleaning liquid (unirradiated) is sprayed onto the substrate 10 as in the third embodiment, and after the substrate 10 is immersed in the cleaning liquid (unirradiated) as in the fourth embodiment. it can.

According to the substrate cleaning apparatus 1, the substrate 10 can be cleaned with a chemical solution having a lower concentration than the conventional one with the same effect as the conventional one. Therefore, in the cleaning process of the substrate 10, the consumption of the chemical solution to be used is suppressed, and at the same time, the amount of the waste liquid is suppressed, so that the cost required for the conventional cleaning process can be greatly reduced.

The cleaning method of the substrate 10 and the cleaning effect of the substrate cleaning apparatus 1 of the present embodiment will be specifically described.

FIG. 8 shows the change in the concentration of Cu contamination remaining on the surface. That is, the effect of the present invention for removing metal contamination is exhibited.
In this experiment, a wafer was used. 10 ¹² atms / cm ²
HCl in pure water on wafers with residual Cu contamination
Was irradiated with ultraviolet rays to a cleaning solution containing 0.1% of H ₂ O ₂ and 0.1% of H ₂ O ₂ , followed by a cleaning treatment. Cu contamination as a result of cleaning
It could be reduced to 10 ¹⁰ atms / cm ² or less.

On the other hand, HCl was 5% and H ₂ O ₂ was 5%.
The cleaning treatment was carried out under the same conditions and method without irradiating with a cleaning liquid containing UV. As a result of cleaning, Cu contamination is 10 ¹⁰
atms / cm ² or less.

Thus, hydrochloric acid was added to the hydrogen peroxide solution,
According to the present invention in which cleaning is performed by irradiating ultraviolet rays, the same metal contamination removal effect as in the cleaning treatment using a cleaning liquid having a concentration of hydrochloric acid of 50 times and a concentration of hydrogen peroxide solution of 50 times was obtained.

FIG. 9 shows the change in the number of contaminant particles remaining on the surface. That is, the effect of the present invention for removing particle contamination is exhibited. In this experiment, a wafer was used. NH3 was added to pure water on the wafer where silica particles contamination of about 100 particles / cm ² remained.
A cleaning solution containing 0.1% of ₄ OH and 0.1% of H ₂ O ₂ was irradiated with ultraviolet rays and then subjected to a cleaning treatment. As a result of the cleaning, the number of contaminated particles could be reduced to 10 particles / cm ² or less.

On the other hand, a cleaning treatment was carried out under the same conditions and with the same cleaning solution containing 2% of NH ₄ OH and 8% of H ₂ O ₂ without irradiating ultraviolet rays. As a result of washing, particle contamination is 1
0 / cm ² or less.

Thus, according to the present invention, in which ammonia is added to the hydrogen peroxide solution and the cleaning is carried out by irradiating ultraviolet rays, a cleaning solution having a 20-fold ammonia concentration and a 80-fold hydrogen peroxide solution concentration is used. The same effect of removing particle contamination as in the cleaning treatment was obtained.

When the wafer is treated with sulfuric acid and hydrogen peroxide to remove the resist, many sulfate ions remain on the surface of the wafer. In order to remove this sulfate ion, it is generally flushed with pure water. At this time, a hydrogen peroxide solution is irradiated with ultraviolet rays to form rinse water, and cleaning is performed with the rinse water. Due to the ultraviolet treatment, the effect of removing sulfate ions is enhanced, and the time (rinse time) for removing sulfate ions is reduced.

FIG. 10 shows the change in the concentration of sulfate ions remaining on the surface. That is, the effect of shortening the rinsing time of the present invention is shown. In this experiment, a wafer was used. 10 ¹³ io
ns / cm ² or more on the wafer where the sulfate ion remains
A cleaning liquid containing 0.01% of H ₂ O ₂ in pure water was irradiated with ultraviolet rays and then subjected to a cleaning treatment. As a result of the washing, sulfate ion contamination was reduced to about 10 ¹⁰ ions / cm ² in about 10 minutes.

On the other hand, cleaning treatment was carried out with pure water under the same conditions and method. As a result of the cleaning, sulfate ion contamination was about 10 ¹² atms / cm ² in about 10 minutes.

Thus, according to the present invention in which the cleaning is performed by irradiating the hydrogen peroxide solution with ultraviolet rays, the number of sulfate ions that can be removed within the same time is 100 times as compared with the case where the treatment is performed only with pure water. It will be double.

In addition, when sulfuric acid and hydrogen peroxide solution are mixed and irradiated with ultraviolet rays to be used for stripping the resist, the dilution is reduced to 1/10 or less as compared with the case where sulfuric acid and hydrogen peroxide solution are simply used. However, the same effect can be obtained.

FIG. 11 shows a change in the amount of the chemical used in the cleaning liquid. That is, the effect of reducing the amount of the used chemical solution is exhibited.

The daily amount of the chemical solution used in each of the cleaning test methods described above was estimated and compared. This is shown in FIG. As shown in FIG. 11, the amount of the chemical used is about 2 to 2.5 liters in the case of the present invention, whereas the amount of the chemical used is about 50 liters in the case of the cleaning liquid which is not irradiated with ultraviolet rays. .

Therefore, according to the present invention, the amount of the chemical used in the cleaning liquid can be reduced to at least 1/20 or less.

As described above, according to the present invention, even if the concentrations of the aqueous solution of hydrogen peroxide and the acidic solution or the alkaline solution are greatly reduced as compared with the conventional one, the same or higher cleaning effect can be obtained. Can be.

[0155]

Since the present invention is constructed and functions as described above, a cleaning solution is prepared by mixing a hydrogen peroxide solution with an alkaline solution or an acidic solution and pure water, and the mixed cleaning solution is irradiated with ultraviolet rays. A method for cleaning a substrate and a method for cleaning a substrate, wherein a cleaning effect having a similar or better cleaning effect can be obtained while using a cleaning liquid having a lower concentration than before by providing a cleaning liquid and a step of cleaning the substrate with an irradiation cleaning liquid immediately after the irradiation. An apparatus can be provided.

Further, since an alkaline solution or an acidic solution is added to the hydrogen peroxide solution and irradiated with ultraviolet rays, not only organic matter contamination but also particle contamination and metal contamination are sufficiently removed, thereby simplifying the cleaning step and using a chemical solution. Can be reduced, and a simple cleaning method and a substrate cleaning apparatus can be provided.

Further, since the amount of the cleaning agent used can be suppressed while maintaining the cleaning effect, an economically efficient substrate cleaning method and a substrate cleaning apparatus capable of reducing the labor and cost for processing and recovering the waste liquid. Can also be provided.

[0158] An acidic solution or an alkaline solution is added to the hydrogen peroxide solution and irradiated with ultraviolet rays, whereby the cleaning power can be increased. Therefore, when cleaning is performed with only the hydrogen peroxide solution, the oxidizing power is increased. The required heating is not required, so that heating equipment is not required, and energy saving can be achieved.

In addition, as the tendency for substrates or silicon wafers to become larger and the aspect ratio to become higher is increasing, sufficient cleaning can be performed on these difficult-to-clean substrates without increasing the amount of cleaning liquid used. Can be realized.

Furthermore, even in the case of a batch-type process which is not appropriate in terms of throughput, a cleaning liquid can be sprayed for each substrate even for a wafer having a diameter of 300 mm or more, so that efficient cleaning can be performed. In addition, at this time, since the amount of the chemical used is sufficiently suppressed, the disadvantage of the single-wafer processing is solved.
The way of using it can be expanded. This makes it possible to provide a substrate cleaning method and a substrate cleaning apparatus that can cope with diversification of the shape, size, and aspect of the substrate.

The cleaning liquid can be activated by irradiating the substrate with the cleaning liquid and simultaneously irradiating the substrate with the cleaning liquid, so that the cleaning liquid can be activated while the cleaning liquid is in contact with the substrate, and the cleaning can be performed when activated. be able to. Further, such processing can reduce the cleaning processing time.

In the apparatus for cleaning a substrate, the light sources are arranged in a plane, and the cleaning liquid irradiation tubes are arranged in parallel so as to form a surface facing the planar light source, or are folded and folded several times to meander. Accordingly, the cleaning liquid can be efficiently irradiated with ultraviolet rays, and the substrate can be cleaned with the cleaning liquid having high cleaning power.

Since the cleaning liquid irradiation tube facing the light source is provided, the amount of ultraviolet rays received by the cleaning liquid is adjusted according to the flow rate and the flow speed of the cleaning liquid activated while passing through the cleaning liquid irradiation tube. Therefore, an irradiation cleaning liquid having an arbitrary cleaning power can be prepared and used.

As described above, in the method for cleaning a substrate including the step of irradiating with ultraviolet rays, the activity of the cleaning solution is reduced while the consumption of the hydrogen peroxide solution and the acidic or alkaline chemical solution is suppressed using a low-concentration cleaning solution. Perform the cleaning in an elevated state,
It is possible to provide a substrate cleaning method and a substrate cleaning apparatus capable of obtaining a good cleaning effect.

[Brief description of the drawings]

FIG. 1 is a flowchart showing one embodiment of a substrate cleaning method of the present invention.

FIG. 2 is a flowchart showing another embodiment of the substrate cleaning method of the present invention.

FIG. 3 is a configuration diagram showing a first embodiment of the substrate cleaning apparatus of the present invention.

FIG. 4 is a configuration diagram showing a second embodiment of the substrate cleaning apparatus of the present invention.

5A shows an example of an irradiation unit, and FIG. 5B shows a cross-sectional configuration diagram of the irradiation unit shown in FIG.

FIG. 6 is a configuration diagram showing a third embodiment of the substrate cleaning apparatus of the present invention.

FIG. 7 is a configuration diagram showing a fourth embodiment of the substrate cleaning apparatus of the present invention.

FIG. 8 shows a change in the concentration of Cu contamination remaining on the surface.

FIG. 9 shows the number of contaminant particles remaining on the surface.

FIG. 10 shows the concentration of sulfate ions remaining on the surface.

FIG. 11 shows a comparison of the amount of a cleaning solution used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate cleaning apparatus 2 Chemical liquid tank 3 Chemical liquid mixing tank 4 Supply pump 5 Irradiation means 6 Operation control means 7 Injection means 8 Drain 9 Waste liquid tank 10 Substrate 11 Waste liquid circulation filter 12 Cleaning tank 2A, 2B, 2C Tank A, tank B, tank C 5a Light source 5b Cleaning liquid irradiation tube 5c Reflector 6a Operation signal 7a, 7b Injection nozzle

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[Procedure amendment]

[Submission date] July 29, 1999 (1999.7.2
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Patent application title: Substrate Cleaning Method and Substrate Cleaning Apparatus

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning a substrate, and more particularly to a method and an apparatus for cleaning a substrate including a step of irradiating ultraviolet rays.

[0002]

2. Description of the Related Art Generally, a semiconductor substrate or a liquid crystal substrate is cleaned by (1) removal of organic substances on a surface, (2) removal of a natural oxide film, (3) removal of heavy metals on a surface, and (4) removal of fine particles. For the purpose of manufacturing semiconductors.

When one of such cleaning steps is insufficient, contamination remaining on a substrate or the like causes a defective product such as a semiconductor. Therefore, the substrate must be completely cleaned.

However, when a long time is required for complete cleaning, the production efficiency is reduced, and when a large amount of cleaning liquid (chemicals) is used, labor and cost are spent for treating chemicals discarded after cleaning. It will be.

[0005] Therefore, it is important to reduce the time required for the substrate cleaning process and to reduce the consumption of the cleaning solution used.

A method for cleaning a substrate is disclosed in Japanese Patent Laid-Open No. Hei 6-2877.
No. 84 discloses a method of irradiating a hydrogen peroxide solution with ultraviolet rays, or cleaning the surface with a mixture of a vapor of the hydrogen peroxide solution and ozone.

[0007]

However, the concentration of the cleaning liquid which can provide a standard cleaning effect in the conventionally used cleaning liquid is relatively high. As the size of the substrate or the silicon wafer is increased and the aspect ratio is increased, the amount of the cleaning liquid used and the amount of the waste liquid are further increased, and the labor and cost spent on the waste liquid purification processing become a heavy burden.

Although throughput is not as good as batch processing (processing a plurality of substrates at once using a cleaning tank), single wafer processing (each substrate is performed one by one) Cleaning treatment).

When the conventional cleaning liquid containing hydrogen peroxide is heated to 60 ° C. or higher in order to increase its oxidizing power, heating equipment is required, energy consumption is large, and the cleaning effect is temporarily reduced. Although increasing, the deterioration with time is remarkable.

Although the use of only hydrogen peroxide solution is effective in removing organic substances, it cannot completely remove particle contamination and metal contamination which are important in semiconductor production.

As described above, in the method of cleaning a substrate including the step of irradiating ultraviolet rays, the consumption of a chemical solution such as an aqueous solution of hydrogen peroxide and an acidic solution or an alkaline solution is suppressed using a low-concentration cleaning solution, and It has been difficult to provide a cleaning method in which the cleaning is performed in a state where the activity of the hydrogen water is enhanced and a good cleaning effect is obtained.

[0012]

The present invention is an object of the invention, such prior art to improve the disadvantages possessed by, substrates conventional level or more washing effect while using a thin cleaning liquid density than traditional obtain cleaning method and a substrate cleaning It is intended to provide a device.

[0013]

[Object of the invention] The present invention has the disadvantages of the prior art.
Improve the hydrogen peroxide solution and alkaline solution or acidic solution
And pure water to obtain a cleaning solution.
Irradiate with ultraviolet light to make an irradiation cleaning liquid, and irradiate immediately after this irradiation
By providing a step of cleaning the substrate with a cleaning liquid,
Using a cleaning solution with a lower concentration than before
Or a method of cleaning a substrate that can provide a higher cleaning effect and
An object of the present invention is to provide a substrate cleaning apparatus.

[0014] Further , since an alkaline solution or an acidic solution is added to the hydrogen peroxide solution and irradiated with ultraviolet rays, not only organic matter contamination but also particle contamination and metal contamination are sufficiently removed, thereby simplifying the cleaning process and using a chemical solution. Can be reduced, and a simple cleaning method and a substrate cleaning apparatus can be provided.

Furthermore, since it is possible while maintaining the cleaning effect to suppress the amount of the cleaning agent, a cleaning method and a substrate cleaning apparatus of good substrate of economic efficiency to reduce such labor and expense to the process recovery of waste Can also be provided.

[Means for Solving the Problems]

According to a first aspect of the present invention, in the substrate cleaning step, a hydrogen peroxide solution, an alkaline solution and pure water are mixed to form a cleaning solution, and the mixed cleaning solution is irradiated with ultraviolet rays. And cleaning the substrate with the irradiation cleaning liquid immediately after the irradiation.

[0017] The hydrogen peroxide solution is the ultraviolet region (especially 350nm
When the hydrogen peroxide solution is irradiated with ultraviolet light having a large absorption in the wavelength region of the following), it reacts as follows to generate a hydroxyl radical. ^{_{2H 2 O 2 → OH - +}} · OH + HO 2 · + H + The hydroxamates Resid radicals also themselves for having oxidizing power, cleaning capacity is synergistically improved.

Moreover, hydrogen peroxide is especially the work is significant alkaline with an oxidizing agent. By utilizing such a property, a higher detergency than in the case of performing ultraviolet irradiation with hydrogen peroxide alone can be obtained, and a detergency equivalent to or higher than the conventional one can be obtained even with a low concentration of hydrogen peroxide. be able to.

[0019] The cleaning solution of the present invention is organic contamination not only particulate contamination, work effectively against metal contamination, but particularly well in the removal of particles in the case of the mixed cleaning solution of the alkali solution and hydrogen peroxide Do.

According to the second aspect of the present invention, in the cleaning step of the substrate, a hydrogen peroxide solution, an alkaline solution and pure water are mixed to form a cleaning liquid, and the mixed cleaning liquid is irradiated with ultraviolet rays to form an irradiation cleaning liquid. A step of injecting the irradiation cleaning liquid onto the substrate immediately after the irradiation is provided.

The cleaning solution is irradiated with ultraviolet rays in a mixture of hydrogen peroxide solution and an alkaline solution and pure water as described above, it is desirable to use immediately for its activity easy decline.
For this reason, the substrate can be washed while maintaining its activity after the irradiation with the ultraviolet rays. Therefore, the irradiation cleaning liquid was sprayed onto the substrate immediately after the irradiation with the ultraviolet rays.

In some cases, a single-wafer processing is more suitable than a badge processing because of an increase in the size of a substrate such as a wafer and an increase in the aspect ratio. According to the present invention, it is possible to reduce the consumption of the cleaning liquid and to perform cleaning of each sheet while covering the defects of the single wafer type.

[0023] In the invention likewise according to claim 3, comprising a step of immersing the substrate in the same manner of irradiation cleaning liquid in the cleaning process. For immersion of the substrate, the substrate is placed in a cleaning tank filled with an irradiation cleaning solution and cleaned. At this time, an ultrasonic wave may be applied.

According to the fourth aspect of the present invention, the first to fifth aspects are provided.
The alkaline solution in each of the inventions was an ammonia solution.

According to the fifth aspect of the present invention, the concentration of ammonia in the cleaning solution is 1/1000% at which the cleaning effect is exhibited.
Not less than 2% and the concentration of the hydrogen peroxide solution is 1/5000.
% Or more and 2% or less.

The cleaning solution conventionally used has an ammonia concentration of 1% to 2% and a hydrogen peroxide concentration of 2% to 4%. Therefore, the concentration of the chemical solution used while maintaining the conventional cleaning effect is maintained. Can be greatly reduced. The combination of ammonia and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

[0027] While the alkaline solution is not limited to ammonia solution, because the residual after washing must not adversely affect the semiconductor and the like, preferably has a volatility.

According to a sixth aspect of the present invention, in the substrate cleaning step, a hydrogen peroxide solution, an acidic solution and pure water are mixed to form a cleaning liquid, and the mixed cleaning liquid is irradiated with ultraviolet rays to form an irradiation cleaning liquid. A step of cleaning the substrate with an irradiation cleaning liquid immediately after the irradiation is provided.

[0029] When hydrogen peroxide is irradiated with ultraviolet rays to greater absorption located aqueous hydrogen peroxide in the wavelength range of the ultraviolet region as described above (in particular 350nm or less), and reacted as follows to generate hydroxyl radicals. ^{_{2H 2 O 2 → OH - +}} · OH + HO 2 · + H + Further, the presence of chloride ions react as follows _{^{Cl - + H 2 O 2 →}} - OCl + H 2 O H 2 O 2 ^{+ HOCl (- OCl) → 1} O 2 + H 2 O + HCl (Cl -) superoxide (singlet oxygen) occurs. Since the superoxide itself has an oxidizing power, the cleaning ability is synergistically improved.

[0030] By utilizing such properties, high detergency can be obtained than the case of performing the ultraviolet irradiation with a hydrogen peroxide solution alone, even conventional equivalent or more washing by aqueous hydrogen peroxide of low concentration You can gain power.

[0031] The cleaning solution of the present invention is organic contamination not only particulate contamination, work effectively against metal contamination, but especially the removal of metal contamination in the case of the mixed cleaning solution of the acid solution and hydrogen peroxide good To do.

According to the seventh aspect of the present invention, in the substrate cleaning step, a hydrogen peroxide solution, an acidic solution and pure water are mixed to form a cleaning liquid, and the mixed cleaning liquid is irradiated with ultraviolet rays to form an irradiation cleaning liquid. A step of injecting the irradiation cleaning liquid onto the substrate immediately after the irradiation is provided.

The cleaning solution is irradiated with ultraviolet rays in a mixture of hydrogen peroxide and the acid solution and pure water as described above, it is desirable to use immediately for its activity easy decline. Therefore, in order to maintain the activity immediately after the ultraviolet irradiation, the irradiation cleaning liquid was sprayed on the substrate immediately after the ultraviolet irradiation.

In some cases, single-wafer processing is more suitable than badge processing because of the increase in the size of substrates such as wafers and the increase in aspect ratio. According to the present invention, it is possible to reduce the consumption of the cleaning liquid and to perform cleaning of each sheet while covering the defects of the single wafer type.

[0035] In the invention likewise eighth aspect, comprising a step of immersing the substrate in the same manner of irradiation cleaning liquid in the cleaning process. For immersion of the substrate, the substrate is placed in a cleaning tank filled with an irradiation cleaning solution and cleaned. At this time, an ultrasonic wave may be applied.

According to the ninth and tenth aspects of the present invention,
The acidic solution in each of the inventions of 5 to 8 is a hydrochloric acid solution,
In the inventions of claims 11 and 12 , a hydrofluoric acid solution is used, and in the inventions of claims 13 and 14 , a sulfuric acid solution is used.

When a hydrochloric acid solution was used, the concentration of hydrochloric acid in the cleaning solution was set at 1/100% to 6%, and the concentration of hydrogen peroxide was set at 1/5000% to 2%.

The cleaning solution conventionally used has a hydrochloric acid concentration of 4% to 6% and a hydrogen peroxide concentration of 4% to 6%.
Therefore, the concentration of the chemical used can be greatly reduced while maintaining the conventional cleaning effect. The combination of hydrochloric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a hydrofluoric acid solution was used, the concentration of the hydrofluoric acid solution in the cleaning solution was 1/500% or more and 1% or less, and hydrogen peroxide was 1/5000% or more and 2% or less.

The cleaning solution conventionally used has a hydrofluoric acid concentration of 0.1% to 1% and a hydrogen peroxide concentration of 0.1%.
% To 2%, the concentration of the chemical used can be greatly reduced while maintaining the conventional cleaning effect.
The combination of hydrofluoric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a sulfuric acid solution was used, the concentration of the sulfuric acid solution in the cleaning solution was 5% or more and 90% or less, and the concentration of the hydrogen peroxide solution was 1/5000% or more and 2% or less.

The cleaning solution used heretofore has a sulfuric acid concentration of 80% to 90% and a hydrogen peroxide concentration of 10% to 20%. Therefore, the concentration of the chemical solution used while maintaining the conventional cleaning effect is maintained. Can be greatly reduced. The combination of sulfuric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

[0043] These, by irradiation with ultraviolet rays is mixed with aqueous hydrogen peroxide, more cleaning ability is enhanced, it is possible to perform this in sufficient cleaning of the substrate in dilute solutions.

According to a fifteenth aspect of the present invention, in the cleaning apparatus for cleaning a substrate, a plurality of chemical liquid tanks for storing a plurality of types of chemical liquids including an alkaline solution or an acidic solution, and a predetermined amount of the chemical liquid to be used is supplied from each chemical liquid tank to a predetermined amount. A chemical mixing tank for injecting and mixing a cleaning liquid, irradiating means for irradiating the cleaning liquid with ultraviolet light, and irradiating means for irradiating the substrate with an irradiation cleaning liquid irradiated with ultraviolet light by the irradiation means to perform cleaning. ing.

[0045] The irradiation means comprises a light source in parallel to the planar with irradiating ultraviolet light, was placed a cleaning liquid irradiation tube to form a surface opposed to the light source.

[0046] each component will be described.

The chemical solution tank is prepared according to the number of types of chemical solution to be used, such as an alkaline solution, an acidic solution, a hydrogen peroxide solution, and a pure water solution.

[0048] These are supplied to the mixing tank the chemical through the tube. The supply amount is adjusted by the valve of each chemical tank,
Thus, the concentration of the chemical contained in the cleaning liquid is determined. As the valve, an electromagnetic valve or the like that opens and closes a switch by electromagnetic force can be adopted.

In the chemical tank, a predetermined amount of chemical is injected, and then the cleaning agent is uniformly mixed.

The irradiation means has a light source and a cleaning liquid irradiation tube. This light source has an absorption band of hydrogen peroxide water of 300.
It is preferable that the irradiation be performed using ultraviolet light of 150 nm to 320 nm. High pressure mercury lamp,
A low pressure mercury lamp can be used. It is also possible to use a xenon lamp having an emission peak at around 250 nm. Preferably, it is desirable to use a large-capacity low-pressure mercury lamp capable of easily obtaining an irradiation intensity of 200 W / cm ² or more. In order to sufficiently irradiate the cleaning liquid, the light sources are desirably arranged in a plane.

The tube for irradiating the cleaning liquid was arranged so as to form a surface facing the light source. The cleaning liquid irradiation tube is intended to sufficiently expose the cleaning liquid to ultraviolet rays. This cleaning liquid irradiation tube is preferably made of quartz or the like so that ultraviolet light can be sufficiently transmitted.

In order to receive sufficient ultraviolet irradiation, it is desirable that the light source be arranged in a plane so as to face the above light source. The term “planar arrangement” means that a plurality of tubes may be arranged in parallel, but one washing liquid irradiation tube is folded back and forth to meander the tubes to increase the surface area. This is in order to sufficiently receive the ultraviolet irradiation.

[0053] installing the reflecting means such as a mirror on the back of the cleaning liquid radiation tube for light source facing to the irradiation is carried out sufficiently.
Thereby, the transmitted ultraviolet light can be reused.

[0054] The length of the cleaning liquid irradiating tube, the thickness, the shape of the cross section or the like, since the irradiation amount of ultraviolet light changes is determined according to the object to be cleaned.

Since the irradiation time of the ultraviolet light changes depending on the amount of the cleaning liquid sent to the cleaning liquid irradiation tube, the flow rate of the cleaning liquid sent to the cleaning liquid irradiation tube must be adjusted according to the state of the object to be cleaned. The adjustment of the flow rate can be performed by a valve.

The injection means is a means for receiving the pressure of a supply pump or the like and spraying the irradiation cleaning liquid or the cleaning liquid evenly on the substrate. It may be a shower-like one or a spray-like one from a nozzle. The jetting means is provided at a position opposed to both sides to jet to the front and back surfaces of the substrate.

[0057] injection of the cleaning liquid by the injection means, it is possible to operate either before or after the process of ultraviolet irradiation. That is, the irradiation cleaning liquid that has been irradiated and activated with ultraviolet rays may be sprayed on the substrate, and the cleaning liquid that has not been irradiated with ultraviolet rays is sprayed onto the substrate, and then the substrate sprayed with the cleaning liquid is irradiated with ultraviolet light. It is also possible.

When using a cleaning liquid which has already been irradiated with ultraviolet rays, the distance between the injection means and the irradiation means must be reduced. This is because the cleaning liquid activated by irradiation with ultraviolet rays deteriorates quickly and is preferably used for cleaning as soon as it is irradiated.

[0059] Thus configured so as not to flow the cleaning liquid stagnates. This is for use before the activated detergency decreases.

Further, a circulating means for recovering and reusing the cleaning liquid used for cleaning may be provided. This is because the cleaning ability is regenerated by removing dirt from the collected cleaning liquid and irradiating ultraviolet rays again, and the cleaning liquid can be reused.

With this configuration, a predetermined type of chemical liquid is supplied from the plurality of chemical liquid tanks to the mixing tank. This amount is controlled by each valve of each chemical solution tank. The supplied chemicals are uniformly mixed in a mixing tank to become a cleaning liquid. The flow rate and pressure of the cleaning liquid are adjusted by a valve and a supply pump provided therewith and sent to the irradiation means.

The irradiating means circulates through a tube made of a material which transmits ultraviolet light such as quartz so as to be sufficiently irradiated by a light source which emits ultraviolet light such as a large-capacity low-pressure mercury lamp. In order to efficiently perform the ultraviolet irradiation, the light sources are arranged in a plane, and the cleaning liquid irradiation tubes are arranged in parallel so as to form a surface facing the planar light source, or folded back and forth to meander.

[0063] cleaning solution while passing through the cleaning liquid irradiation tube is activated. The amount of the irradiated ultraviolet rays is adjusted by the flow rate and the flow rate of the cleaning liquid. Specifically, the flow rate and the flow rate are controlled by a predetermined valve controlled by the operation control means provided in combination.

The cleaning of the substrate may be performed by spraying the irradiation cleaning liquid, which has been irradiated with ultraviolet rays, uniformly from the front and back surfaces of the substrate to be cleaned into a shower from the spray nozzle.
It may be carried out by immersing in a washing tank. However, it is not allowed to stay for a long time after the irradiation with the cleaning liquid, and the cleaning liquid is used for cleaning immediately after the irradiation. This is because the detergency increased by the irradiation of ultraviolet rays decreases with time.

[0065] According to the cleaning method and cleaning apparatus, it is possible to clean the substrate with a conventional equal or more effective than the chemical is lower than the conventional concentrations.

[0066] Thus, in the cleaning step of the substrate, also the pressing time waste liquid when pressing the consumption of the chemical to be used, the cost has been required in the prior washing step can be significantly reduced.

[0067]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart showing one embodiment of the present invention.

In the cleaning process of the substrate 10, step 1
If necessary in (S1), preprocessing is performed. The cleaning is performed if necessary with an organic solvent or the like.

In step 2 (S2), a hydrogen peroxide solution, an alkaline solution and pure water, or a hydrogen peroxide solution, an acidic solution and pure water are mixed. This becomes the cleaning liquid.

In step 3 (S3), the cleaning liquid is irradiated with ultraviolet rays. This becomes the irradiation cleaning liquid.

In step 4 (S4), the irradiation cleaning liquid is sprayed on the substrate 10, or the substrate 10 is immersed in the irradiation cleaning liquid.

[0072] subjected to a post-treatment if necessary at Step 5 (S5). A treatment such as rinsing is performed after the resist is stripped with sulfuric acid and hydrogen peroxide.

The method of cleaning the substrate 10 according to the present embodiment includes such steps, and particularly includes the characteristic steps of S2, S3, and S4.

[0074] describing the contents of each step. Step 2
The hydrogen peroxide solution and the alkaline solution or the acidic solution and the water in (S2) are mixed at a predetermined ratio. The ratio is arbitrarily determined depending on the type and structure of the substrate 10 to be cleaned.

In step 3 (S3), ultraviolet rays are irradiated to activate the cleaning solution. Hydrogen peroxide has a large absorption in an ultraviolet region (especially 350 nm or less), and when ultraviolet light is irradiated on the hydrogen peroxide, it reacts as follows to generate hydroxyl radicals. ^{_{2H 2 O 2 → OH - +}} · OH + HO 2 · + H + The hydroxamates Resid radical, since the itself has an oxidizing power, cleaning capacity is improved.

[0076] Hydrogen peroxide water is particularly its work is significant alkaline with an oxidizing agent. By utilizing such a property, a higher detergency can be obtained than when ultraviolet irradiation is performed using only hydrogen peroxide solution, and a detergency equivalent to the conventional one can be obtained even with a low concentration of hydrogen peroxide solution. .

[0077] cleaning solution of the present invention is organic contamination not only particulate contamination, work effectively against metal contamination, but better to remove the particles in particular in the case of the mixed cleaning solution of the alkali solution and hydrogen peroxide .

[0078] In the presence of chloride ions react as follows ^{_{Cl - + H 2 O 2 →}} - OCl + H 2 O H 2 O 2 + HOCl (- OCl) → 1 O 2 + H 2 O + HCl (Cl ⁻ ) Superoxide (singlet oxygen) is generated. Since the superoxide itself has oxidizing power, the cleaning ability is improved.

[0079] By utilizing such properties, high detergency can be obtained than the case of performing the ultraviolet irradiation in hydrogen peroxide alone or when adding an acidic solution, prior by hydrogen peroxide of low concentration The same detergency can be obtained.

[0080] The cleaning solution of the present invention is organic contamination not only particulate contamination, work effectively against metal contamination, but especially the removal of metal contamination in the case of the mixed cleaning solution of the acid solution and hydrogen peroxide good To do.

In step 4, the activated irradiation cleaning liquid was sprayed on the substrate 10 immediately after activation, or the substrate 10 was immersed in the irradiation cleaning liquid.

Since the activity of the irradiation cleaning liquid irradiated with ultraviolet rays is apt to decline, it is desirable to use the cleaning liquid immediately. Therefore, the irradiation cleaning liquid was sprayed on the substrate 10 immediately after the ultraviolet irradiation in order to maintain the activity after the ultraviolet irradiation.

Further , step 3 and step 4 can be performed simultaneously. That is, a step of irradiating the substrate 10 with ultraviolet light at the same time as spraying the cleaning liquid onto the substrate 10 was provided . A process process one by one substrate by such as this can also reduce the processing time required for cleaning.

Next, it will be described with FIG Comparative Example. FIG.
9 is a flowchart showing another embodiment of the present invention.

In the cleaning process of the substrate 10, step 1
If necessary in 1 (S11), preprocessing is performed. The cleaning is performed if necessary with an organic solvent or the like.

In step 12 (S12), a hydrogen peroxide solution, an alkaline solution and pure water, or a hydrogen peroxide solution, an acidic solution and pure water are mixed. This becomes the cleaning liquid.

In step 13 (S13), the cleaning liquid is sprayed on the substrate 10 or the substrate 10 is immersed in the cleaning liquid.

In step 14 (S14), the substrate 1 is kept in this state (the state where the cleaning liquid is sprayed and the state where it is immersed in the cleaning liquid).
0 is irradiated with ultraviolet rays.

[0089] subjected to a post-treatment, if necessary in the step 15 (S15). A treatment such as rinsing is performed after the resist is stripped with sulfuric acid and hydrogen peroxide.

The method of cleaning the substrate 10 of this comparative example includes such steps, and particularly includes the characteristic steps of S13 and S14.

[0091] The embodiment described above is different, previously injects the cleaning liquid to the substrate 10, or the substrate 10 is immersed in the cleaning liquid. Then, in a state where the cleaning liquid is applied to the substrate 10 (a state where the cleaning liquid is sprayed, a state where the cleaning liquid is immersed in the cleaning liquid),
0 is irradiated with ultraviolet rays. The same means can be used for other common light sources. However, when irradiating with ultraviolet light in a state of being immersed, the substrate 10
And the incident direction of ultraviolet rays are appropriately determined.

Since the activity of the irradiation cleaning liquid after the irradiation of the ultraviolet light is easily deteriorated, the ultraviolet light is irradiated after the cleaning liquid contacts the substrate 10 (while the cleaning liquid is in contact with the substrate 10). Since the cleaning liquid is activated while being in contact with the substrate 10, the nascent radical can be sufficiently utilized.

The same effect can be obtained by simultaneously irradiating the substrate 10 with the cleaning liquid and irradiating the substrate 10 with ultraviolet rays.

[0094] it is possible to shorten the processing time required for cleaning be processing of one by one substrate by this process.

[0095] Next will be described chemical solution used in the two embodiments described above. Here, an alkaline solution and an acidic solution are used. Ammonia solution was mainly used for the alkaline solution. The alkaline solution is not limited to an ammonia solution, but is preferably a volatile one because it should not remain after cleaning and adversely affect a semiconductor or the like. On the other hand, as the acidic solution, a hydrochloric acid solution, a hydrofluoric acid solution, and a sulfuric acid solution were used as typical examples.

[0096] The concentration of ammonia in the cleaning solution, 1 /
1000% or more and 2% or less, and the concentration of the hydrogen peroxide solution is 1
/ 5000% or more and 2% or less. The cleaning solution used conventionally has an ammonia concentration of 1% to 2% and a hydrogen peroxide concentration of 2% to 4%. Therefore, it is necessary to greatly reduce the concentration of the chemical solution used while maintaining the conventional cleaning effect. Can be. The combination of ammonia and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

[0097] hydrochloric acid solution used as the acidic solution, a hydrofluoric acid solution, the concentration of sulfuric acid solution is as follows.

When a hydrochloric acid solution was used, the concentration of hydrochloric acid in the cleaning solution was 1/100% to 6%, and the concentration of hydrogen peroxide was 1/5000% to 2%. The cleaning solution used conventionally has a hydrochloric acid concentration of 4% to 6% and a hydrogen peroxide concentration of 4% to 6%. Therefore, it is necessary to greatly reduce the concentration of the chemical solution used while maintaining the conventional cleaning effect. Can be. The combination of hydrochloric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a hydrofluoric acid solution was used, the concentration of the hydrofluoric acid solution in the cleaning solution was 1/500% or more and 1% or less, and hydrogen peroxide was 1/5000% or more and 2% or less. Conventionally used cleaning solutions have a hydrofluoric acid concentration of 0.1% to 1%,
Since the concentration of hydrogen peroxide is 0.1% to 2%, it is possible to greatly reduce the concentration of the used chemical solution while maintaining the conventional cleaning effect. The combination of hydrofluoric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

When a sulfuric acid solution was used, the concentration of the sulfuric acid solution in the cleaning solution was 5% or more and 90% or less, and the concentration of the hydrogen peroxide solution was 1/5000% or more and 2% or less. Conventionally used cleaning solutions have a sulfuric acid concentration of 80% to 90% and a hydrogen peroxide concentration of 10% to 20%. Therefore, the concentration of the chemical solution used must be greatly reduced while maintaining the conventional cleaning effect. Can be. The combination of sulfuric acid and hydrogen peroxide can greatly reduce the concentration of one drug and keep the concentration of one drug at a conventional level.

[0102] These, by irradiation with ultraviolet rays is mixed with aqueous hydrogen peroxide, more cleaning ability is enhanced, it is possible to perform this in sufficient cleaning of the substrate 10 in dilute solutions.

[0102] Next, the substrate cleaning apparatus 1 will be described with reference to FIGS. 3-7. FIG. 3 shows a first embodiment of the substrate cleaning apparatus 1. The substrate cleaning apparatus 1 includes a plurality of chemical tanks 2 for storing a plurality of chemical liquids including an alkaline solution, an acidic solution, hydrogen peroxide solution, and pure water, and a predetermined amount of a chemical liquid to be used is injected from each chemical liquid tank 2. Chemical mixing tank 3 for mixing into cleaning liquid
Irradiating means 5 for irradiating the cleaning liquid with ultraviolet light;
And an injecting means 7 for injecting and cleaning.

The chemical solution tank 2 is prepared according to the number of types of chemical solution to be used, such as an alkaline solution, an acidic solution, a hydrogen peroxide solution, a pure water solution, and the like, and includes tanks 2A, 2B, 2C, and 2D. It is prepared according to the number of kinds of medicines used. The supply timing and supply amount of these are controlled by valves A, B, C, and D provided in each tank 2A and the like. As the valve, an electromagnetic valve or the like that opens and closes a switch by electromagnetic force can be adopted.

The mixing tank 3 is a tank for mixing the chemicals supplied from each chemical liquid tank 2. The mixing tank 3 mixes the cleaning agent uniformly after injecting a predetermined amount of the chemical solution. Since the amount of the chemical solution supplied to the mixing tank 3 is adjusted by a valve of each of the chemical tanks 2, a cleaning liquid is formed in the mixing tank 3 at a predetermined concentration of the chemical solution.

The cleaning liquid produced in the mixing tank 3 is sent to the irradiation means 5. The irradiation unit 5 has a light source 5a and a cleaning liquid irradiation tube 5b. Since the light source 5a has a wavelength of 300 nm or less, which is an absorption band of a hydrogen peroxide solution,
Irradiation using ultraviolet light of 0 nm is desirable. High-pressure mercury lamps and low-pressure mercury lamps can be used. Also 250
It is also possible to use a xenon lamp having an emission peak around nm. Preferably, the irradiation intensity is 200
It is desirable to use a large-capacity low-pressure mercury lamp capable of easily obtaining W / cm ² or more.

[0106] The light source 5a is desirably arranged in a planar shape. This is for sufficiently irradiating the cleaning liquid. Therefore, the light sources 5a may be arranged in parallel so as not to interfere with each other.

The cleaning liquid irradiating tube 5b is arranged so as to form the light source 5a arranged in a plane and the surface facing the light source 5a. Since the cleaning liquid irradiation tube 5b aims at sufficiently exposing the cleaning liquid to ultraviolet rays, it is preferable to use quartz or the like so that ultraviolet light can be sufficiently transmitted.

[0108] The irradiation unit 5 as specifically arranged as shown in FIG. 5 (a) is a perspective view thereof, and 5 (b) is a sectional view thereof.

To arrange in a plane means that a plurality of tubes may be arranged in parallel, but in the example shown in FIG. 5, one washing liquid irradiation tube is folded back and forth to meander. This is because the surface area to be irradiated is increased so that ultraviolet irradiation can be sufficiently received. The cleaning liquid is activated by being irradiated with ultraviolet light while passing through the meandering quartz tube and is provided for cleaning.

A reflecting mirror 5c is provided on the back of the cleaning liquid irradiation tube 5b facing the light source so that the irradiation is sufficiently performed.
Thereby, the transmitted ultraviolet light can be reused.

[0111] The length of the cleaning solution irradiation tube 5b, thickness, depending on the shape of the cross section or the like, since the irradiation amount of ultraviolet light changes is determined according to the object to be cleaned.

[0112] Further, the amount of the cleaning liquid fed into the washing liquid irradiating tube 5b, for changing the irradiation time of the ultraviolet light,
The flow rate of the cleaning liquid sent to the cleaning liquid irradiation tube must be adjusted according to the state of the object to be cleaned. The adjustment of the flow rate can be performed by the valve F. The amount of the cleaning liquid sent into the cleaning liquid irradiation tube 5b and the amount of the irradiation cleaning liquid sent out from the irradiation unit 5 can be related to the amount of the irradiation cleaning liquid sent out from the injection unit 7. Therefore, these amounts can be controlled according to the cleaning process of the substrate 10, and can be managed by the operation control unit 6.

The irradiation cleaning liquid which has been irradiated with the ultraviolet rays is sent to the injection means 7. The injection unit 7 is a unit that receives the pressure of the supply pump 4 or the like and evenly sprays the irradiation cleaning liquid or the cleaning liquid on the substrate 10. Shower-like things,
It may be sprayed in a mist form from a nozzle. The jetting means 7 is provided at a position opposed to both sides to jet to the front and back surfaces of the substrate 10.

The substrate cleaning apparatus 1 shown in FIG . 3 is provided with an injection nozzle 7a and an injection nozzle 7b, which are injection means 7 in the form of a nozzle. The ejection nozzle 7a ejects the irradiation cleaning liquid from the front surface of the substrate 10, and the ejection nozzle 7b ejects the irradiation cleaning liquid from the back surface of the substrate 10. With these two nozzles, the substrate 1
0 is sufficiently in contact with the washing solution.

The distance between the injection means 7 and the irradiation means 5 needs to be reduced. This is because the cleaning liquid activated by irradiation with ultraviolet rays deteriorates quickly and is preferably used for cleaning as soon as it is irradiated.

[0116] Thus configured so as not to flow the cleaning liquid stagnates. This is for use before the activated detergency decreases.

[0117] Also, showing a second embodiment a method of cleaning is different in FIG. The substrate cleaning apparatus 1 of FIG. 4 cleans the substrate 10 by immersing the substrate 10 in a cleaning tank with an irradiation cleaning liquid. The substrates 10 are immersed together in the cleaning tank 4. Thus, the stain is removed by the activated cleaning liquid. This enables generally faster processing than washing one by one.

The cleaning liquid used for cleaning the substrate 10 passes through the drain 8 and removes contaminants through the waste liquid circulation filter 11. The regenerated cleaning liquid is returned to the mixing tank 3 and used again for cleaning.

[0119] It is also possible that features a circulating means for utilizing again recovered cleaning solution used in this way. This allows
By removing dirt from the collected cleaning liquid and irradiating ultraviolet rays again, the cleaning ability is regenerated and can be reused.

[0120] FIG. 6 shows the substrate cleaning apparatus 1.First comparative example
And in FIG.Second comparative exampleIs shown.First and second comparison
An exampleIs different from the first and second embodiments in that the
This is performed after spraying the cleaning liquid or after immersing in the cleaning liquid.

The first comparative example has means for injecting a cleaning liquid onto the substrate 10 as in the first embodiment, and the second comparative example has a cleaning tank in which the substrate 10 is immersed as in the second embodiment. Having.

[0122] In other words, prior to the injection of the cleaning solution to the substrate 10,
Alternatively, the substrate 10 is immersed in a cleaning liquid. Then, the substrate 10 is irradiated with ultraviolet rays in a state where the cleaning liquid is applied to the substrate (a state where the cleaning liquid is sprayed or a state where the cleaning liquid is immersed in the cleaning liquid).

In the second comparative example , when irradiating ultraviolet rays in a immersed state, the arrangement of the substrates 10 and the incident direction of the ultraviolet rays are determined as appropriate so that the ultraviolet rays are not blocked by the arranged substrates 10. .

Since the activity of the irradiation cleaning liquid after the irradiation of the ultraviolet light is easily deteriorated, the irradiation of the ultraviolet light is performed after the cleaning liquid contacts the substrate 10 (while the cleaning liquid is in contact with the substrate 10). Since the cleaning liquid is activated while being in contact with the substrate 10, the nascent radical can be sufficiently utilized.

The same effect can be obtained by simultaneously irradiating the substrate 10 with the cleaning liquid and irradiating the substrate 10 with ultraviolet rays.

[0126] With this configuration, a plurality of chemical bath 2 of a predetermined type chemical solution is supplied in a predetermined quantity mixing vessel 3. This amount is controlled by each valve of each chemical solution tank 2. The supplied chemical liquid is made uniform in the mixing tank 3 and becomes a cleaning liquid. The flow rate and pressure of the cleaning liquid are adjusted by a valve E and a supply pump 4 attached thereto, and the cleaning liquid is sent to the irradiation means 5.

The irradiation means 5 circulates a cleaning liquid irradiation tube 5b made of a material which transmits ultraviolet light such as quartz so as to be sufficiently irradiated by a light source 5a which emits ultraviolet light such as a large-capacity low-pressure mercury lamp. In order to efficiently perform the ultraviolet irradiation, the light sources 5a are arranged in a plane as shown in FIG. 5, and the cleaning liquid irradiation tubes 5b are arranged in parallel so as to constitute a surface facing the planar light source, or Turn back and forth in layers.

[0128] cleaning solution while passing through the cleaning liquid irradiating tube 5b is activated. The amount of the irradiated ultraviolet rays is adjusted by the flow rate and the flow rate of the cleaning liquid. In particular,
The flow rate and flow rate are controlled by a predetermined valve controlled by the operation control means 6 provided in parallel.

[0129] cleaning of the substrate 10, the irradiation cleaning liquid irradiated with ultraviolet rays as in Example 1 or 3, the injection nozzle 7
a and 7b, even when the substrate 10 to be cleaned is sprayed uniformly from the front and back surfaces in the form of a shower,
Alternatively, as shown in 4, it may be carried out by immersing in a washing tank.

[0130] The irradiation of ultraviolet rays, after injection into the substrate 10 to the cleaning liquid (unirradiated) as in Example 3, is also possible to perform the substrate 10 as in Example 4 was immersed in the cleaning liquid (unirradiated) it can.

[0131] According to the substrate cleaning apparatus 1, it is possible to clean the substrate 10 with the same effect as conventional by chemical lower than conventional levels. Therefore, in the cleaning process of the substrate 10, the consumption of the chemical solution to be used is suppressed, and at the same time, the amount of the waste liquid is suppressed, so that the cost required for the conventional cleaning process can be greatly reduced.

[0132] The cleaning method and cleaning effect of the substrate cleaning apparatus 1 of the substrate 10 of this embodiment will be described.

FIG . 8 shows the change in the concentration of Cu contamination remaining on the surface. That is, the effect of the present invention for removing metal contamination is exhibited.
In this experiment, a wafer was used. 10 ¹² atms / cm ²
HCl in pure water on wafers with residual Cu contamination
Was irradiated with ultraviolet rays to a cleaning solution containing 0.1% of H ₂ O ₂ and 0.1% of H ₂ O ₂ , followed by a cleaning treatment. Cu contamination as a result of cleaning
It could be reduced to 10 ¹⁰ atms / cm ² or less.

[0134] In contrast, the HCl 5%, the H ₂ O ₂ 5%
The cleaning treatment was carried out under the same conditions and method without irradiating with a cleaning liquid containing UV. As a result of cleaning, Cu contamination is 10 ¹⁰
atms / cm ² or less.

[0135] As a result, the hydrochloric acid was added to the hydrogen peroxide solution,
According to the present invention in which cleaning is performed by irradiating ultraviolet rays, the same metal contamination removal effect as in the cleaning treatment using a cleaning liquid having a concentration of hydrochloric acid of 50 times and a concentration of hydrogen peroxide solution of 50 times was obtained.

FIG . 9 shows the change in the number of contaminant particles remaining on the surface. That is, the effect of the present invention for removing particle contamination is exhibited. In this experiment, a wafer was used. NH3 was added to pure water on the wafer where silica particles contamination of about 100 particles / cm ² remained.
A cleaning solution containing 0.1% of ₄ OH and 0.1% of H ₂ O ₂ was irradiated with ultraviolet rays and then subjected to a cleaning treatment. As a result of the cleaning, the number of contaminated particles could be reduced to 10 particles / cm ² or less.

[0137] In contrast, 2% NH ₄ OH, without irradiation of ultraviolet rays with a washing solution containing 8% H ₂ O _2, and the cleaning process in the same conditions and methods. As a result of washing, particle contamination is 1
0 / cm ² or less.

[0138] Thus, the ammonia was added to the hydrogen peroxide, according to the present invention for cleaning by irradiating ultraviolet rays, 20 times the concentration of ammonia, the concentration of hydrogen peroxide solution was used 80 times washing liquid The same effect of removing particle contamination as in the cleaning treatment was obtained.

When the wafer is treated with sulfuric acid and hydrogen peroxide to remove the resist, many sulfate ions remain on the surface of the wafer. In order to remove this sulfate ion, it is generally flushed with pure water. At this time, a hydrogen peroxide solution is irradiated with ultraviolet rays to form rinse water, and cleaning is performed with the rinse water. Due to the ultraviolet treatment, the effect of removing sulfate ions is enhanced, and the time (rinse time) for removing sulfate ions is reduced.

FIG . 10 shows the change in the concentration of sulfate ions remaining on the surface. That is, the effect of shortening the rinsing time of the present invention is shown. In this experiment, a wafer was used. 10 ¹³ io
ns / cm ² or more on the wafer where the sulfate ion remains
A cleaning liquid containing 0.01% of H ₂ O ₂ in pure water was irradiated with ultraviolet rays and then subjected to a cleaning treatment. As a result of the washing, sulfate ion contamination was reduced to about 10 ¹⁰ ions / cm ² in about 10 minutes.

[0141] In contrast, the pure water, and cleaning treatment in the same conditions and methods. As a result of the cleaning, sulfate ion contamination was about 10 ¹² atms / cm ² in about 10 minutes.

[0142] Thus, according to the present invention for cleaning by irradiating ultraviolet rays to the hydrogen peroxide solution, as compared with the case of processing only with pure water, ion number of sulfate ions which can be removed in the same time 100 It will be double.

In addition, when sulfuric acid and hydrogen peroxide solution are mixed and irradiated with ultraviolet rays to be used for stripping the resist, the dilution is reduced to 1/10 or less as compared with the case where sulfuric acid and hydrogen peroxide solution are simply used. However, the same effect can be obtained.

FIG . 11 shows a change in the usage amount of the chemical contained in the cleaning liquid. That is, the effect of reducing the amount of the used chemical solution is exhibited.

The daily amount of the chemical solution used in each of the cleaning test methods described above was estimated and compared. This is shown in FIG. As shown in FIG. 11, the amount of the chemical used is about 2 to 2.5 liters in the case of the present invention, whereas the amount of the chemical used is about 50 liters in the case of the cleaning liquid which is not irradiated with ultraviolet rays. .

[0146] Thus, the amount of the chemical liquid used in the cleaning solution according to the present invention can be reduced to at least 1/20 or less.

[0147] It this way, according to the present invention, even when substantially lower the concentration of hydrogen peroxide and an acidic solution or alkaline solution than the conventional, to obtain a conventional manner or more washing effect Can be.

[0148]

Since the present invention is constructed and functions as described above, a cleaning solution is prepared by mixing a hydrogen peroxide solution with an alkaline solution or an acidic solution and pure water, and the mixed cleaning solution is irradiated with ultraviolet rays. A method for cleaning a substrate and a method for cleaning a substrate, wherein a cleaning effect having a similar or better cleaning effect can be obtained while using a cleaning liquid having a lower concentration than before by providing a cleaning liquid and a step of cleaning the substrate with an irradiation cleaning liquid immediately after the irradiation. An apparatus can be provided.

Further , since an alkaline solution or an acidic solution was added to the hydrogen peroxide solution and irradiated with ultraviolet rays, not only organic matter contamination but also particle contamination and metal contamination were sufficiently removed, and the cleaning process was simplified and the chemical solution used was reduced. Can be reduced, and a simple cleaning method and a substrate cleaning apparatus can be provided.

[0150] Further, since it is possible while maintaining the cleaning effect to suppress the amount of the cleaning agent, cleaning method and a substrate cleaning apparatus of good substrate of capable of reducing economic efficiency of such effort and expense to the process recovery of waste Can also be provided.

An acidic solution or an alkaline solution is added to a hydrogen peroxide solution and irradiated with ultraviolet rays, whereby the detergency can be increased. Therefore, in the case of washing with only a hydrogen peroxide solution, the oxidizing power is increased. The required heating is not required, so that heating equipment is not required, and energy saving can be achieved.

In addition, as the tendency of substrates or silicon wafers to increase in size and increase in aspect ratio is increasing, sufficient cleaning can be performed on these difficult-to-clean substrates without increasing the amount of cleaning liquid used. Can be realized.

[0153] Further, not suitable in the processing of a batch in terms of throughput, can be carried out efficient cleaning by spraying a cleaning liquid for every one substrate also more wafer diameter 300 mm. At this time, since the amount of the chemical used is sufficiently suppressed, the drawback of the single-wafer processing can be solved, and the use of the processing can be expanded. This means
It is possible to provide a substrate cleaning method and a substrate cleaning apparatus that can cope with diversification of the shape, size, and aspect of the substrate.

In the substrate cleaning apparatus, the light sources are arranged in a plane, and the cleaning liquid irradiation tubes are arranged in parallel so as to form a surface facing the planar light source, or are folded back and forth in several layers to meander. Accordingly, the cleaning liquid can be efficiently irradiated with ultraviolet rays, and the substrate can be cleaned with the cleaning liquid having high cleaning power.

Since the cleaning liquid irradiating tube facing the light source is provided, the amount of ultraviolet rays received by the cleaning liquid is adjusted by the flow rate and the flow speed of the cleaning liquid activated while passing through the cleaning liquid irradiating tube. Therefore, an irradiation cleaning liquid having an arbitrary cleaning power can be prepared and used.

[0156] Thus, in the cleaning method of a substrate comprising the step of irradiating ultraviolet rays, with a low concentration of the cleaning liquid, after suppressing the consumption of hydrogen peroxide solution and an acidic or alkaline chemical, the activity of the cleaning solution Perform the cleaning in an elevated state,
It is possible to provide a substrate cleaning method and a substrate cleaning apparatus capable of obtaining a good cleaning effect.

[Brief description of the drawings]

FIG. 1 is a flowchart showing one embodiment of a substrate cleaning method of the present invention.

FIG. 2 is a flowchart illustrating a comparative example .

FIG. 3 is a configuration diagram showing a first embodiment of the substrate cleaning apparatus of the present invention.

FIG. 4 is a configuration diagram showing a second embodiment of the substrate cleaning apparatus of the present invention.

5A shows an example of an irradiation unit, and FIG. 5B shows a cross-sectional configuration diagram of the irradiation unit shown in FIG.

FIG. 6 is a configuration diagram illustrating a first comparative example of the substrate cleaning apparatus .

FIG. 7 is a configuration diagram illustrating a second comparative example of the substrate cleaning apparatus .

FIG. 8 shows a change in the concentration of Cu contamination remaining on the surface.

FIG. 9 shows the number of contaminant particles remaining on the surface.

FIG. 10 shows the concentration of sulfate ions remaining on the surface.

FIG. 11 shows a comparison of the amount of a cleaning solution used.

[Description of Signs] 1 Substrate cleaning device 2 Chemical liquid tank 3 Chemical liquid mixing tank 4 Supply pump 5 Irradiation means 6 Operation control means 7 Injection means 8 Drain 9 Waste liquid tank 10 Substrate 11 Waste liquid circulation filter 12 Cleaning tank 2A, 2B, 2C Tank A , Tank B, tank C 5a light source 5b cleaning liquid irradiation tube 5c reflector 6a operation signal 7a, 7b jet nozzle

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/304 642 H01L 21/304 642E 643 643A 647 647Z 648 648G

Claims (19)

[Claims] In a method for cleaning a substrate, a cleaning solution is prepared by mixing a hydrogen peroxide solution, an alkaline solution and pure water, and the mixed cleaning solution is irradiated with ultraviolet rays to form an irradiation cleaning solution. And a step of cleaning the substrate. 2. A method for cleaning a substrate, comprising mixing a hydrogen peroxide solution, an alkaline solution, and pure water to form a cleaning solution, irradiating the mixed cleaning solution with ultraviolet rays to form an irradiation cleaning solution, and immediately after the irradiation, the irradiation cleaning solution. A step of injecting the substrate onto the substrate. 3. A method for cleaning a substrate, comprising mixing a hydrogen peroxide solution, an alkaline solution, and pure water to form a cleaning solution, irradiating the mixed cleaning solution with ultraviolet rays to form an irradiation cleaning solution, and immediately after the irradiation, the irradiation cleaning solution. A step of immersing the substrate in the substrate. 4. A method for cleaning a substrate, comprising a step of mixing a hydrogen peroxide solution, an alkaline solution, and pure water to form a cleaning liquid, spraying the cleaning liquid on the substrate, and simultaneously irradiating the substrate with ultraviolet rays. A method for cleaning a substrate, comprising: 5. A method for cleaning a substrate, comprising mixing a hydrogen peroxide solution, an alkaline solution, and pure water into a cleaning solution, immersing the substrate in the mixed cleaning solution, and irradiating the immersed substrate with ultraviolet light. A method for cleaning a substrate, comprising a step. 6. The method according to claim 1, wherein the alkaline solution is an ammonia solution. 7. The cleaning solution wherein the concentration of hydrogen peroxide is 1 /
5000% or more and 2% or less, and the concentration of ammonia is 1%.
The method for cleaning a substrate according to claim 6, wherein the content is not less than / 1000% and not more than 2%. 8. A method for cleaning a substrate, comprising mixing a hydrogen peroxide solution, an acidic solution and pure water to form a cleaning liquid, irradiating the mixed cleaning liquid with ultraviolet rays to obtain an irradiation cleaning liquid, and immediately after the irradiation, the irradiation cleaning liquid. And a step of cleaning the substrate. 9. A method for cleaning a substrate, comprising mixing a hydrogen peroxide solution, an acidic solution and pure water to form a cleaning liquid, irradiating the mixed cleaning liquid with ultraviolet rays to obtain an irradiation cleaning liquid, and immediately after the irradiation, the irradiation cleaning liquid A step of injecting the substrate onto the substrate. 10. A method for cleaning a substrate, comprising mixing a hydrogen peroxide solution, an acidic solution, and pure water to form a cleaning solution, irradiating the mixed cleaning solution with ultraviolet rays to obtain an irradiation cleaning solution, and immediately after the irradiation, the irradiation cleaning solution. A step of immersing the substrate in the substrate. 11. A method for cleaning a substrate, comprising a step of mixing a hydrogen peroxide solution, an acidic solution and pure water to form a cleaning liquid, and simultaneously irradiating the substrate with ultraviolet light while injecting the cleaning liquid onto the substrate. A method for cleaning a substrate, comprising: 12. A method for cleaning a substrate, comprising mixing a hydrogen peroxide solution, an acidic solution and pure water to form a cleaning solution, immersing the substrate in the mixed cleaning solution, and irradiating the immersed substrate with ultraviolet light. A method for cleaning a substrate, comprising a step. 13. The method according to claim 8, wherein the acidic solution is a hydrochloric acid solution. 14. The cleaning solution wherein the concentration of hydrogen peroxide is 1
/ 5000% or more and 2% or less, and the concentration of hydrochloric acid is 1/1.
14. The amount is not less than 00% and not more than 6%.
The method for cleaning a substrate according to the above. 15. The method for cleaning a substrate according to claim 8, wherein the acidic solution is a hydrofluoric acid solution. 16. The cleaning solution according to claim 15, wherein the concentration of the hydrogen peroxide is 1/5000% or more and 2% or less, and the concentration of hydrofluoric acid is 1/500% or more and 1% or less. The method for cleaning a substrate according to the above. 17. The method for cleaning a substrate according to claim 8, wherein the acidic solution is a sulfuric acid solution. 18. The cleaning solution, wherein the concentration of the hydrogen peroxide is 1/5000% or more and 2% or less, and the concentration of sulfuric acid is 5% or less.
The method for cleaning a substrate according to claim 17, wherein the concentration is not less than 90% and not more than 90%. 19. A cleaning apparatus for cleaning a substrate, comprising: a plurality of chemical tanks for storing a plurality of types of chemicals including an alkaline solution or an acidic solution; and a supply of a predetermined amount of the chemical used from the chemical tank. A chemical liquid mixing tank that mixes a chemical liquid into a cleaning liquid, an irradiation unit that irradiates the cleaning liquid with ultraviolet light, and an injection unit that performs cleaning by injecting the irradiation cleaning liquid irradiated with ultraviolet light by the irradiation unit onto the substrate, A substrate cleaning apparatus, characterized in that the irradiating means irradiates ultraviolet light and arranges a light source arranged in a plane and a cleaning liquid irradiation tube so as to form a surface facing the light source.