KR100202761B1 - Cleaning method of semiconductor substrate and apparatus thereof - Google Patents

Abstract

In the final cleaning step of the semiconductor substrate of the present invention, the gas stream material containing i) 10 ^-6 to 100% of the gas to be provided with reducibility is the first mixed solution prepared by dissolving the acid in the supercritical water and supercritical water, A second mixed solution prepared by dissolving alkali in a supernatant, at least under a pressure of at least 10 ^-3 atmospheres, ii) a first mixed solution prepared by dissolving the acid in the supernatant, And a second mixed solution prepared by dissolving alkali in the purified water. The negative electrode water having a negative oxidation-reduction potential and a pH of 7 to 13 is prepared by adjusting the dissolved oxygen concentration in the cleaning solution At the same time used as a washing solution, or iii) the cathode can be an inert gas atmosphere of 10 ^-3 atmospheres containing gas provided that the reducible give ^10-6 to 100% It is used under.

Description

Cleaning method and cleaning apparatus for semiconductor substrate

FIG. 1 is a graph showing the relationship between the pH value and the oxidation-reduction potential of the cleaning solution,

FIG. 2 is a graph showing the relationship between the removal of contaminants from the treated surface and the mixing time of the cathode water and the anode water, and FIG.

FIG. 3 is a flow chart illustrating a cleaning process using a mixture of cathode water and anode water,

FIG. 4 is a flow chart illustrating a portion of a conventional process,

FIG. 5 is a flow chart including a case where the anode water and the cathode water are separately supplied,

FIG. 6 is a schematic view showing an example of a processing system according to the first aspect of the present invention,

7 is a schematic view showing an example of a processing system according to a second aspect of the present invention,

FIG. 8 is a graph showing the number of water mark particles remaining on the surface of the silicon substrate after cleaning by the method of the present invention,

Figure 9 is a cross-sectional view of a bipolar transistor substrate prepared to illustrate how the cleaning method of the present invention is applied in a semiconductor manufacturing apparatus,

FIG. 10 is a graph showing the electrical characteristics of the bipolar transistor substrate shown in FIG. 9,

FIG. 11 is a graph showing the electrical characteristics of a bipolar transistor substrate including a case where HF treatment and ordinary purification treatment are applied to a semiconductor substrate in the manufacture of a bipolar transistor,

FIG. 12 is a schematic diagram illustrating a processing system according to a preferred embodiment of the present invention,

FIG. 13 is a schematic diagram illustrating a processing system according to a third embodiment of the present invention,

FIG. 14 is a graph showing the cleaning effect on the surface of the silicon substrate as the number of remaining water marks,

FIG. 15 is a schematic diagram illustrating a portion of a processing system according to a third embodiment of the present invention,

FIG. 16 is a schematic diagram illustrating another portion of a processing system according to a third embodiment of the present invention. FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

1, 301, 321: super-purified water production device 2, 8: electrolyte container

3: anode 4: cathode

5: Ion exchange member 6:

15: waste solution 61, 62: electrolyte ion water

7, 71, 72, 309, 342: wafers 9, 91, 92:

11, 111, 112: Fluoric acid container

81: silicon substrate 82: n ⁺ layer

83: base layer 84, 89: p ⁺ -type polysilicon lead layer

85: n ⁺ -type polysilicon lead layer 86: oxide film

87: collector electrode 88: base electrode

90: insect repellent electrode 101: region of negative electrode water

102: region of anode water 120, 402: gas addition means

121, 122: Fluoric acid solution 211, 212, 304: Gas-liquid separator

308, 341: Wafer holder 306, 326:

14, 231, 232, 310, 345: leads 261, 262:

307: Surface treatment apparatus 324: Bubble generator

343: internal processing unit 344: external processing unit

348: Multiple 311, 401, 403: Pipe

801 and 802:

31, 315, 322, 325, 346, the valve is closed,

901, 902, 903, 904: voltage between collector and base

The present invention relates to a method for cleaning a semiconductor substrate, and more particularly to a method for cleaning a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film.

In the manufacturing process of the semiconductor device, removing the remaining impurities on the surface of the semiconductor crystal is very important because these remaining impurities seriously affect the quality of the semiconductor device manufactured. For example, if it is a silicon crystal, impurities that remain on the crystal surface, such as natural oxide films, organic contaminants, and heavy metals, make it very difficult to precisely control the thin gate oxide film, Causing deterioration such as a breakdown voltage in the electrical characteristics of the semiconductor device. These impurities also make it difficult to form desirable metal resistance contacts, thereby increasing the series resistance and causing degradation of the rectifying characteristics. It is understood that thorough cleaning of the semiconductor crystal surface in the manufacture of semiconductor devices is absolutely necessary to form a clean surface without any remaining impurities.

However, conventional techniques for cleaning semiconductor substrate surfaces leave room for further improvement. In fact, the reduced performance of semiconductor substrates is in many cases attributed to contamination of the crystal surface of the substrate. Thus, such a problem can be overcome by removing contaminants in the substrate manufacturing process.

The RCA cleaning technique (W. Kern RCA Review Vol. 31 (1970), which includes the formation of an oxide film covering a silicon substrate, has been known as a technique to overcome the known difficulties described above. The impurities remaining on the surface of the silicon substrate, for example, carbon and oxygen are transferred to the oxide film before the oxide film is formed. Therefore, when the oxide film having residual impurities transferred to these oxide films is removed, It can be understood that a clean silicon substrate surface is obtained.

In the case of the RCA cleaning technique described above, Is first formed on the surface of the silicon substrate, and then the substrate is cleaned under a vacuum in which the silicon substrate is not contaminated to remove the oxide film, for example, under a pressure of about 10 ^-8 Pa Or more to obtain a clean substrate surface. The oxide film can be relatively easily formed by this method. Furthermore, even if the substrate is left in the atmosphere, the silicon substrate can be handled easily because the inner surface between the silicon substrate and the oxide film is protected by the oxide film.

However, when a large silicon substrate having a diameter of at least 6 inches is subjected to heat treatment in a vacuum apparatus of RCA cleaning technology, it is required to enlarge the vacuum apparatus, which increases the apparatus cost. In addition, the complex processing steps involved in RCA cleaning technology increase the likelihood of contamination of the substrate during processing.

In addition, RCA cleaning techniques, which involve complex processing steps, require large amounts of chemicals and pure water, thus increasing cleaning costs and causing air or water pollution problems. Of course, developing simpler cleaning techniques is very important in this technology.

In addition, recent laminated circuits and the like, in which recent miniaturization has become prominent, have made absolutely necessary to use a semiconductor manufacturing process to form a substrate having another semiconductor device in a semiconductor device previously formed in the semiconductor manufacturing process . In such a semiconductor manufacturing process, the oxide film covering the surface of the semiconductor substrate is partially exposed in the region near the semiconductor device formed in advance to form the bare pattern, and then the semiconductor layer is laminated on the bare pattern. In recent years, this process is required to be performed at a low temperature. In detail, all the heat treatments included in the entire process for manufacturing the semiconductor device are, for example, 800 Or at lower temperatures. Of course, the heat treatment included in the process for cleaning the surface of the silicon substrate is also performed at a low temperature.

However, an effective process for satisfactorily cleaning the silicon substrate surface at a low temperature has not yet been developed.

In a treatment in which heat treatment at a high temperature is not provided, it is necessary to remove the oxide film formed on the silicon substrate surface immediately before forming the substrate region. In general, treatment with a fluoride type solution such as an HF solution and a NH ₄ F solution is done for this purpose. Treatment with the HF solution is advantageous in that the surface of the hydrogen-terminated silicon substrate after the removal of the native oxide film is relatively stable in the atmosphere. After the treatment with the HF solution, the surface of the silicon substrate is generally treated with water to ensure safety. However, silicon oxide complexes, referred to as water glasses, remain on the silicon substrate surface after treatment with purified water. It is known that the electrical properties of a substrate formed on a substrate deteriorate in the presence of water glass. Of course, it is very important to develop a method that allows water glass formed on the silicon substrate surface to be removed in this technical field.

Repeatedly, it is very important to develop a technique for satisfactorily cleaning the surface of semiconductor crystals. However, conventional techniques require large amounts of chemicals and water for cleaning purposes because they require many processing steps. In general, it is sought seriously to develop a simplified method that reduces a number of processing steps, thus lowering the manufacturing cost of the semiconductor device. If a number of iron steps are reduced, the amount of chemicals and water used for cleaning purposes will also be reduced. As already pointed out, reduced amounts of chemicals will also inhibit air pollution and water pollution problems.

A further problem in the conventional process of cleaning the surface of a silicon substrate is that it is substantially impossible for the impurity to be completely removed from the substrate surface by the cleaning process. In order to produce a semiconductor substrate showing satisfactory electrical properties, it is very important to completely remove impurities from the substrate surface.

The obvious conclusion is that it is very important to develop a method for cleaning the surface of semiconductor crystals that allows the impurities to be removed sufficiently from the substrate surface by a simplified process step.

It is an object of the present invention, which is obtained in view of the above-described circumstances, to provide a method for effectively cleaning the surface of a semiconductor substrate more easily and more safely.

It is still another object of the present invention to provide a cleaning method of the present invention to manufacture a high-performance semiconductor device at low manufacturing cost.

Hereinafter, the present invention will be described in detail.

According to a first aspect of the present invention, there is provided a semiconductor device comprising: a bare pattern formed by partially exposing a surface of a semiconductor substrate covered with an oxide film; a first mixed solution prepared by dissolving an acid in ultra pure water, And a second mixed solution prepared by dissolving alkali in a supercritical water. The method of cleaning a semiconductor substrate according to claim 1, The treatment is carried out in a closed system using cathode water obtained by electrolyzing a cleaning solution, the cathode water having a negative oxidation-reduction potential and a pH of 7 to 13 and an oxygen concentration dissolved in the cathode water of 300 ppb or less And a cleaning method of the semiconductor substrate.

According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film to a first mixed solution prepared by dissolving an acid in a supersubstance, And a second surface treatment step of treating the surface of the semiconductor substrate with at least one cleaning solution selected from the group consisting of a second mixed solution prepared by dissolving the cleaning solution in the surface treatment step, In a closed system under an atmosphere of an inert gas of 10 ^-3 atmospheres containing 10 ^-6 to 100% of a gas flow material which is provided so as to give reducibility by using the cathode water obtained by decomposition, and the cathode water has a negative oxidation reduction potential And a pH of 7 to 13, will be.

According to a third aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film to a first mixed solution prepared by dissolving an acid in an ultra- And a surface treatment step of surface-treating the surface of the semiconductor substrate with at least one cleaning solution selected from the group consisting of a first mixed solution prepared by dissolving the first solution and a second mixed solution prepared by dissolving the second solution, wherein the final cleaning treatment included in the surface treatment step In a closed system using a final cleaning solution prepared by bringing a gas stream material containing the provided 10 ^-6 to 100% gas into contact with a cleaning solution, said gas stream material having a pressure of at least 10 ^-3 atm Wherein the cleaning solution is generated by contact with a cleaning solution under pressure. It is.

Further, according to a fourth aspect of the present invention,

Means for supplying a cleaning solution selected from the group consisting of a first mixed solution prepared by dissolving an acid in a superscript constant and a superscript constant, and a second mixed solution prepared by dissolving alkali in a supersubstance,

Means for applying a gas flow material containing 10 < ^-6 > to 100% gas to the cleaning solution so as to provide reduction in the cleaning solution under a pressure of at least 10 < ^-3 &

Disclosed is an apparatus for cleaning a semiconductor substrate comprising a means for performing a surface treatment using a cleaning solution having a reducing-dispersing gas species material in a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film.

Here, the cleaning apparatus forms a closed system.

The cleaning methods and devices of the present invention allow substantially complete removal of silicon oxide from the substrate surface after the cleaning process and also reduce the number of processing steps required in conventional surface treatment techniques of semiconductor substrate surfaces at low temperatures . In addition to reducing the number of processing steps and shortening the processing time, the present invention also allows a cleaning system that is itself simplified, thereby reducing the number of facilities used including piping.

The present invention also makes it possible to more effectively and safely provide a clean surface of a semiconductor substrate effectively. In general, the cleaning technique of the present invention produces high performance semiconductor devices at low cost.

Hereinafter, the present invention will be described in more detail.

In a normal cleaning method applied to the surface of a silicon substrate, the treatment with the HF solution is provided in combination with the treatment with the super clean water. The oxide film formed on the surface of the silicon substrate is removed without fail by treatment with an HF solution performed at a low temperature such as room temperature. However, fine silicon oxide particles (referred to herein as water marks) are formed on the surface of the silicon substrate by a stepwise cleaning process using ultrasound. Although not observed immediately after the HF treatment, the water mark confirmed after the water treatment treatment tends to cause deterioration in the electrical characteristics of the product semiconductor substrate.

It is understood that immediately after the treatment with the HF solution, fluorine remains on the silicon substrate. In general, it is not desirable to transfer the HF-treated silicon substrate directly to the next step. This is because the remaining fullerene on the substrate has a deleterious effect on the operation and corrodes the device. Clearly, it is absolutely necessary to remove the remaining fluorine by washing with a supernatant.

The inventors have found that it is effective to use electrolytic ionized water obtained by electrolyzing water to remove fluorine left on the surface of a silicon substrate. It has been found that when electrolytic ionized water having a high pH is used to clean the surface of a silicon substrate, the remaining fluorine can be removed on the silicon substrate surface without forming an oxide film or the like. It has been found that water mark formation can be prevented when using the specific electrolyte ionized water according to the present invention.

According to a first aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a bare pattern formed by partially exposing a surface of a semiconductor substrate covered with an oxide film to a first mixed solution prepared by dissolving an acid in a supersubstance, And a second mixed solution prepared by dissolving the first cleaning solution, wherein the final cleaning treatment included in the surface treatment step is a cleaning treatment of the semiconductor substrate, Wherein the cathode water has a negative redox potential and a pH of 7 to 13 and the oxygen concentration dissolved in the cathode is maintained at 300 ppb or less. And to provide a cleaning method of a substrate.

According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film to a first mixed solution prepared by dissolving an acid in a supersubstance, And a surface treatment step of performing surface treatment with at least one cleaning solution selected from the group consisting of a first mixed solution prepared by dissolving the first mixed solution and a second mixed solution prepared by dissolving the second mixed solution, a gas flow material that is provided so as to ^10-6 is performed to the cleaning solution in an inert gas atmosphere of 10 ^-3 atmospheres containing 100% in a closed system by using the number of the negative electrode obtained by the electrolysis, the cathode may have a negative redox A cleaning method of a semiconductor substrate having a dislocation and a pH of 7 to 13 .

According to one of the first and second aspects of the present invention, the silicon substrate surface is a group consisting of a first mixed solution prepared by dissolving an acid in a superscript constant, a superscript constant, and a second mixed solution prepared by dissolving an alkali in a supersaturation Lt; / RTI > The acids used to prepare the first mixed solution include, for example, hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, and hydrogen peroxide. The alkalis used to prepare the second mixed solution include, for example, ammonia water and organic alkali compounds. The final cleaning treatment included in the substrate surface treatment step is performed using the cathode water obtained by electrolyzing the cleaning solution, and the cathode water has a negative oxidation-reduction potential and a pH value of 7 to 13, And is important from the second point of view. It is possible to obtain a cleaning effect substantially the same as that obtained by a conventional treatment using a mixed solution containing various kinds of acid and alkali solutions without causing water mark generation due to a specific cleaning treatment. It is also possible to reduce the amount of chemical used in the cleaning process as compared to conventional methods. It is understood that the method according to any one of the first and second aspects of the present invention ensures safety of operation, reduces consumption of chemicals, and simplifies the cleaning process.

In the method according to the first aspect of the present invention, the dissolved oxygen concentration in the cathode water used is maintained at 300 ppb or less, which prevents oxidation of the semiconductor substrate, for example, the silicon substrate by oxygen dissolved in the cleaning solution .

In the process according to the second aspect of the present invention, the cleaning is carried out under an inert gas atmosphere of at least 10 -3 atm, preferably at least 1 atmosphere, which makes it possible to overly dissolve oxygen in the cleaning solution. In general, the silicon substrate also prevents oxidation by oxygen dissolved in the cleaning solution. In addition, the inert gas comprises 10-6% to 100% of the gas stream material provided for imparting reducibility. In general, the production of silicon oxide and water marks can be prevented by reducing the function of the inert gas, and it is possible to obtain a cleaning effect substantially the same as that obtained in a conventional treatment method using a mixture of various acid and alkali solutions . As the gas stream material provided so as to be given reducibility, hydrogen radicals having energy states different from those of hydrogen gas and hydrogen gas are preferably used. The inert gas used in the method according to any one of the first and second aspects of the present invention also includes, for example, nitrogen, helium, and argon.

In the method according to any one of the first and second aspects of the present invention, it is possible to add an anode water to the cathode water. When anode water is used, metallic contaminants, such as primarily undesirable residual copper, can be dissolved in the cleaning solution and thus removed from the substrate surface.

FIG. 1 is a graph showing the relationship between the pH value of the cleaning solution and the redox potential. FIG. In FIG. 1, the region enclosed by the straight line 101 represents the range of the number of cathodes, and the region surrounded by another straight line 102 represents the range of the number of the anodes. In order to effectively suppress water mark generation, it is necessary to use a cathode water having an oxidation-reduction potential of about -1.0 V and a pH value of 7 to 13, and this is contained in the region surrounded by the straight line 101. On the other hand, it is necessary to use an anode water having an oxidation-reduction potential of about 0.5 to 1.5 V.

After the cleaning process, the silicon substrate may be dried by conventional methods, such as heating, nitrogen gas blowing, ultrasonic application, and rotation of the substrate. In addition, the substrate having the droplets of electrolytic ion water left on the substrate can be dried naturally in the atmosphere of the present invention in which sufficient cleaning effect is obtained.

The apparatus for producing electrolytic ionized water can be used to produce anode and cathode water. If all the anode and cathode recovered from the manufacturing apparatus and stored in the container are continuously left in the atmosphere, the cleaning effect of the cathode water is maintained for 2 days continuously, and the cathode water is continuously maintained for several hours do. The effective period of the known time coincides with the time required for the redox potential in the anode water or cathode water to return to zero.

2 shows the substrate cleaning ability of the cleaning solution when the cleaning solution is prepared by mixing the anode water and the cathode water. The washing solution prepared by mixing the anode water and the cathode water has a sufficient washing ability for about 10 minutes after the mixing step. Since the cleaning treatment applied to the semiconductor substrate is generally performed for several minutes, the mixed solution composed of the anode water and the cathode water can be satisfactorily used for the cleaning treatment applied to the substrate.

FIG. 3 is a flow chart illustrating a cleaning process including a treatment with a cleaning solution prepared by mixing an anode water and an anode water. For comparison, FIG. 4 is a partial flow chart included in a typical process. FIG. 5 is also a partial flow chart included in the process provided in the present invention, wherein the anode and cathode numbers are provided separately to the system for the cleaning process.

When the mixed cleaning solution is used as shown in FIG. 3, it is possible to simultaneously obtain the cleaning effect obtained by both the anode water number and the cathode water number. As a result, the surface treatment for cleaning purposes may be completed by applying a cleaning treatment to the substrate only once, after the treatment with the mixed cleaning solution. The treatment steps substantially corresponding to the treatment of the anode water and the initial water as shown in FIG. 5 can be excluded when using a mixed cleaning solution as shown in FIG. In addition, the process involving treatment with electrolytic ionized water, as shown in FIG. 3 or FIG. 5, allows to omit at least one treatment step using the superscript constant shown in FIG. Also, as shown in FIG. 4, treatment with an HF solution can also be omitted when providing the process shown in FIG. 3.

The method according to the first aspect of the present invention is characterized in that at least one cleaning solution selected from the group consisting of a first mixed solution prepared by dissolving an acid in a superscript constant and a superscript constant and a second mixed solution prepared by dissolving alkali in a supersubstance, Means for separating the cathode redox potential from the produced electrolyte ion water and the cathode water having a pH value of 7 to 13, means for adjusting the oxygen concentration dissolved in the cathode water to 300 ppb or less, A cleaning apparatus of an airtight system consisting of means for applying a surface treatment to a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film using a cathode water having a dissolved oxygen concentration.

The method according to the second aspect of the present invention is also characterized in that the first mixed solution prepared by dissolving the acid in the superscript and superscript constants and the second mixed solution prepared by dissolving the alkali in the superscript essence, Means for electrolyzing the solution and separating the negative electrode water having a negative oxidation-reduction potential and the pH value of 7 to 13 from the generated number of electrolyte ions, means for supplying a gas-like material provided so as to impart reducing property to the cathode water, And means for applying a surface treatment to a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film using a cathode water having a gas flow material supplied thereto by means of a cleaning device of an airtight system Lt; / RTI >

According to a third aspect of the present invention, there is provided a semiconductor device comprising: a first mixed solution prepared by dissolving an acid in a supercritical water, a supercritical water, and a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film; And a second mixed solution prepared by dissolving the first and second mixed solutions, wherein the final cleaning step included in the surface treatment step is provided so as to be given a reducing property In a closed system using a final cleaning solution prepared by contacting a gaseous material comprising 10-6% to 100% of the gaseous material in contact with said cleaning solution, said gaseous material having a pressure of at least 10 < -3 & Which is generated by contact with a cleaning solution under the conditions .

According to a third aspect of the present invention, the surface of the silicon substrate is a cleaning solution selected from the group consisting of the first mixed solution prepared by dissolving the acid in the superscript constant and the superscript constant, and the second mixed solution prepared by dissolving the alkali in the supersaturation . The acid used to prepare the first mixed solution includes, for example, hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, and hydrogen peroxide. In addition, the alkalis used to prepare the second mixed solution include, for example, ammonia water and organic alkaline compounds. It is important that the gas stream material provided to be reducted is added to the cleaning solution in the final cleaning process. In such a case, the reducing function formed by the gas stream substance suppresses the formation of silicon oxide and water marks, which makes it possible to obtain substantially the same cleaning effect as that obtained in a conventional method using a mixed solution containing various acid and alkali solutions Make it possible. In addition, the amount of chemical agent used can also be reduced by the method according to the third aspect of the present invention in comparison with conventional methods. It is understood that the present invention is capable of ensuring the safety of the cleaning operation, reducing the amount of chemical used and simplifying the cleaning process.

Above all, when a gas stream material is generated by contact with a cleaning solution under a pressure of at least 0.1, preferably at least 10 ^-3 atm, a gas stream containing 10 ^-6 to 100% Should be sufficiently soluble in the cleaning solution.

In the third aspect of the present invention, it is also possible to prepare electrolytic ionized water by electrolyzing in advance a mixed solution prepared by dissolving a supersubstance or an acid or alkali. In such a case, the cathode water having a negative oxidation-reduction potential should be separated from the obtained electrolytic ion water and the gas stream material provided to be reducted should be added to the separated cathode water for use in the final cleaning step. The specific method makes effective use of the characteristics of the anode and cathode water and makes it possible to obtain substantially the same cleaning effect as that obtained in a conventional method using a mixed solution containing various acid and alkali solutions. For example, in the case of using the cathode water separated from the electrolytic ion water produced by electrolyzing the supercritical water, the formation of silicon oxide can be suppressed by the reduction function of the specific cathode water. Optionally, a cleaning solution having a large pH value can also be used to clean the silicon substrate surface, while at the same time inhibiting the formation of oxide films and the like on the substrate surface. In addition, silicon oxide formation can be hindered when using a supercritical water for cleaning purposes.

It should be noted that the anode water allows the removal of metallic contaminants from the silicon substrate surface. In other words, the cathode water allows the removal of particles from the substrate surface. As a result, the amount of chemical agent used can be reduced in a method according to the third aspect of the present invention compared to conventional methods. It is understood that the method of the present invention ensures safety in the cleaning process, reduces the amount of chemical used, and simplifies the cleaning process. In addition, the number of pre-manufactured cathode or anode is harmless, which makes it possible to use a specific number of cathodes or anodes in the final stage of the cleaning process.

In the present invention, it is preferable to use hydrogen radicals having energy states different from that of hydrogen gas and hydrogen gas as the gas stream material provided so as to be given reducibility. Hydrogen radicals having different energy states from hydrogen gas can be produced by decomposing hydrogen gas by means of photolysis, electron collision, heating, and the like. Further, the hydrogen radical can be formed when the initial water is electrolyzed. In the case of using a mixed gas prepared by adding excited species having an excited energy state or excited species of hydrogen gas, the method of the present invention can obtain a better cleaning effect than the case of using hydrogen gas alone. In particular, when hydrogen radicals different in energy state from hydrogen gas and hydrogen gas are dissolved together in the supercritical water, it becomes possible to shorten the cleaning time so as to reduce the roughness of the (100) plane of the silicon substrate, OH ^- ions in ion water. This reduces the processing cost and makes it possible to obtain a clean bare surface with improved flatness.

Generally, the cleaning solution in the processing vessel is exposed to the atmosphere, and as a result, oxygen gas or the like in the atmosphere is dissolved in the cleaning solution. Usually the silicon substrate surface is oxidized by dissolved oxygen. Although the cleaning solution is alkaline, the cleaning effect can not be avoided if the concentration of dissolved oxygen is no longer reduced. To overcome this problem, the present invention adjusts the gas concentration dissolved in the cleaning solution. The preferred adjustment of the dissolved gas concentration is to lower the gas concentration in the cleaning solution. Further, the cleaning solution is applied to the processing vessel with the oxygen concentration kept low in the cleaning solution. Further, the processing vessel containing the specific cleaning solution is closed and closed or is removed under a controlled gas flow atmosphere. As a result, the method of the present invention can achieve a satisfactory cleaning effect.

After the cleaning treatment, the silicon substrate may be dried by conventional methods, for example, heating, nitrogen gas blowing, ultrasonic application, and rotation of the substrate. Further, in the present invention, in which a sufficient amount of electrolyte solution ion solution remains on the substrate, a substrate can be naturally dried in the air.

The method according to the third aspect of the present invention can be carried out using an apparatus according to the fourth aspect of the present invention. More specifically, an apparatus for cleaning a semiconductor substrate according to the fourth aspect of the present invention is made by the following means.

Means for supplying a cleaning solution selected from the group consisting of a first mixed solution prepared by dissolving an acid in a supercritical water and a supernatant and a second mixed solution prepared by dissolving alkali in a supernatant,

Means for applying a gas flow containing 10 < ^-6 > to 100% of gas supplied to the reducing solution to the cleaning solution under a pressure of at least 10 < ^-3 >

A means for performing a surface treatment using a cleaning solution having a reducing-dispersing gas flow material added as a cleaning solution to a bare pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film,

Here, the cleaning apparatus forms a closed system.

The apparatus according to the fourth aspect of the present invention preferably further comprises a pressing means for pressing the gas flow material to allow the gas flow material to be dissolved in the cleaning solution.

The pressure is preferably 0.01 atm or higher.

For a more detailed description of the invention, reference is made to the accompanying drawings. Above all, FIG. 6 schematically illustrates a cleaning system according to the first aspect of the present invention, wherein the cathode water is used as a cleaning solution. In detail, the supercritical water 6 supplied from the apparatus 1 for producing the supercritical water is applied to the electrolyte vessel 2. By applying a voltage between the anode 3 and the cathode 4, the supercritical water 6 is electrolyzed via the ion exchange member 5 to produce the electrolytic ionized water 61 and 62. The obtained electrolytic ionized water 61 is applied to the processing vessel 801 and simultaneously the electrolytic ionized water 61 is applied to the processing vessel 802. The wafer 71 held in the wafer case 91 is processed in the processing vessel 801 on the anode surface. Similarly, the wafer 72 held in the wafer case 92 is processed on the anode surface in the processing vessel 801 . The lids 231 and 232, which can be closed in a closed manner, are placed on the processing vessels 801 and 802, respectively, in order to prevent dust, oxygen gas, carbon dioxide gas, etc. in the air from entering these processing vessels.

In the present invention, the surface treatment of the silicon wafer having the bare pattern formed by partially exposing the silicon wafer coated with the oxide film uses the electrolytic ionized water 62 applied to the treatment vessel, ). ≪ / RTI > Further, if necessary, it is possible to further surface-treat the wafer in the processing container 801 on the anode surface. The electrolytic ionized water 61, the electrolytic ionized water 61, and the electrolytic water are selectively supplied through the valves 101 and 102 to the fluoric acid solutions 121 and 122 provided in the prepared fluoric acid containers 111 and 112, It is also possible to remove the oxide film from the silicon substrate surface by adding it to the silicon substrate 62. Further, the gas-liquid separator 211 provided between the electrolyte container 2 and the process container 801 and the gas-liquid separator 211 provided between the electrolyte container 2 and the process container 802, It is desirable to dispose the other gas-liquid separator 212 to remove undesirable gases produced in the electrolyte vessel 2 through the valves 221,

According to a first aspect of the present invention, the oxygen concentration dissolved in the electrolytic ionized water can be adjusted to a predetermined level in advance, or the degassing means 261, 262 are connected to the gas-liquid separators 211, . When the dissolved oxygen concentration is 300 ppb or less, the silicon wafer is prevented from being oxidized by dissolved oxygen.

FIG. 7 schematically shows a processing system according to a second aspect of the present invention. FIG. 7, the degassing means 261 included in the system shown in FIG. 6 is not used in the system shown in FIG. 7, but in the processing system shown in FIG. 7, the gas adding means 120 Is substantially the same as that shown in Fig. 6, except that it is installed via the valve 141 between the electrolyte container 2 and the process container 802. Fig. The gas addition means 120 provides a clean gas 130 containing a desired concentration of reducing gas that pressurizes the electrolyte ion water, which makes it possible to more effectively prevent the silicon wafer from being oxidized. It is preferable that the clean gas is supplied at a pressure of 10 < ^-3 >, preferably 1 atm, and the reducing gas is contained at 10 < ^-6 > If necessary, a degassing means 261 may be provided.

FIG. 8 is a graph showing the number of water marks remaining on the surface of a silicon wafer after a cleaning process performed using a specified number of cathodes in the method according to the first aspect of the present invention. FIG. For comparison, FIG. 8 also shows the remaining water mark immediately after the normal treatment with the HF treatment and the water mark remaining immediately after the HF sole treatment. 8, when the surface treatment of a bare pattern formed by partially exposing a silicon wafer coated with an oxide film as in the present invention is performed using a negative oxidation-reduction potential and a cathode water having a pH value of 7 to 13, The water mark remained on the silicon substrate which can not be removed by the normal treatment of the primary water channel can be removed substantially completely in the HF single treatment. Above all, it should be noted that the method of the present invention allows to remove substantially completely remaining water marks without applying a heat treatment under vacuum or a combined wet process.

More specifically, a silicon substrate coated with an oxide film is partially removed to form a bare pattern surrounded by an oxide film. The native oxide film is then formed in the bare pattern. Under these conditions, the substrate is treated with an HF solution, then a normal treatment with primer water is applied, and then the substrate is dried. In this case, if 10 or more water marks are 5 5 It is found in a bare pattern of ^two sizes.

When the silicon substrate is dried immediately after the HF treatment, the water mark is not found at all within the same sized bare pattern.

Further, when the silicon substrate is treated with the cathode water as in the present invention, the water mark is not observed at all in a bare pattern of the same size, or one water mark is observed. The experimental data shown in FIG. 8 clearly support that the specific cleaning process of the present invention removes the water marks that remain on the silicon substrate, especially after the cleaning step, and the water marks formed during the cleaning step and during the drying step after the cleaning step. It is understood that the cleaning method of the present invention, including the treatment of cathode channels, allows improved cleaning effects compared to conventional cleaning of silicon substrate surfaces.

FIG. 9 shows the installation of a bipolar transistor substrate, which is prepared for ease of explanation of how to apply the cleaning method according to the first aspect of the present invention. In detail, the cleaning method of the present invention is provided for cleaning the surface area located between the base layer 83 and the n ^{+ -type} layer 82 of p-type stack growth. In order to prepare a bipolar transistor substrate, an n + -type layer 82 is formed on an n-type silicon substrate 81, followed by a base layer 83 of p-type stack growth on an n + -type layer 82, . Next, a p + -type polysilicon lead layer 84, a p + -type polysilicon lead layer 89, and an n + -type polysilicon lead layer 85 are formed in such a manner that they are separated from each other by an oxide film 86 The collector electrode 87, the base electrode 88, and the emitter electrode 90 are formed. The cleaning method of the present invention is provided for cleaning the surface of the n + -current collector layer 82 immediately before forming the base layer 83 of the p-type lamination growth.

FIG. 10 shows the V-I characteristics of the installation of the bipolar transistor shown in FIG. 9, wherein the silicon substrate surface between the base region and the current collector region is cleaned by the cleaning method of the present invention as already described in FIG. The curves 901 and 902 shown in FIG. 10 encompass cases where the voltage between the current collector and the base is high and low, respectively.

For comparison, FIG. 11 shows the V-I characteristics of the installation of the bipolar transistor shown in FIG. 9, wherein the silicon substrate surface is cleaned by a conventional silicon substrate cleaning method provided with HF treatment and normal treatment with initial water. The multiple curves shown in FIG. 11 encompass each case where the voltage between the collector and the base is high (903) and low (904).

Deterioration in electrical properties is evident from the eleventh road in the case of providing a conventional substrate surface cleaning method. Conventional cleaning treatments fail to adequately clean the substrate surface between the base and the collector area, and as a result, the contaminants remain partially unremoved on the substrate surface. The deterioration in the electrical properties shown in FIG. Is believed to be induced by the lack of electrical current due to the residual contaminants described in < RTI ID = 0.0 > In other words, the cleaning treatment provided in the present invention allows to sufficiently inhibit the deterioration in question, as is apparent from FIG. 10.

FIG. 12 is a schematic representation of a processing system according to a preferred embodiment of the present invention, wherein the cleaning solution used is made by mixing cathode water and anode water. As shown in the figure, the supercritical water 6 supplied from the apparatus 1 for producing the supercritical water is applied to the electrolyte vessel 2. By applying a voltage between the anode 3 and the cathode 4, the supercritical water 6 is electrolyzed via the ion exchange member 5 to obtain electrolytic ionized water 61 and 62. Liquid separator 211 is arranged between the anode surface of the electrolyte container 2 and the processing vessel 8. The water- Likewise, the gas-liquid separator 212 is arranged between the cathode surface of the electrolyte vessel 2 and the processing vessel 8. The undesirable gas flow produced in the electrolyte vessel 2 is removed by these gas-liquid separation devices 211 and 212. Particularly, the degassing device 261 connected to the gas-liquid separating device 211 or the degassing device 261 and the separating device 211 appropriately installed between the electrolyte container 2 and the process container 8 are not required to exceed the predetermined level It is effective to control the dissolved oxygen concentration in the anode water. This is very important because it is very important to remove the oxygen gas generated by electrolysis to prevent the engine surface from being oxidized by dissolved oxygen in the cleaning solution.

The electrolyzed ionized water streams 61 and 62 flow through the switch valves 131 and 132, respectively, to be mixed with each other. The mixed electrolytic ionized water stream is applied to the processing vessel 8. Thus, the wafer 7 held in the processing vessel 8 is treated as a mixed stream applied to the vessel 8. It is known that the processing vessel is closed closed by the lid 14. Further, the waste solution 15 is discharged from the treatment vessel 8 through the drain valve 16. As is apparent from the figure, the mixing ratio of the anode water 61 to the cathode water 62 is such that a single stream of the anode water 61 and the cathode water 62, as well as a stream of the mixed solution, (171), (132), and (172), as desired by the appropriate operation of the switch valves (131), (171), (132) and (172).

In addition, the fluoric acid solution 12 stored in the prefabricated fluoric acid container 11 may be added to the electrolytic ionized water 6 via the valve 10 to remove the oxide film formed on the silicon substrate surface in the required step . In this case, the dissolved oxygen in the fluoric acid solution 12 can be removed by connecting the degasser 262 to the fluoric acid container 11.

As previously described, the open upper portion of the processing vessel 8 is sealingly closed by the lid 14. As a result, it is possible to prevent dust, oxygen, carbon dioxide, etc. contained in the air from entering the processing container 8. Further, the surface cleaning treatment can be applied to the wafer 7 without removing the wafer 7 out of the processing vessel 8. Alternatively, it is possible to perform a continuous cleaning process.

In the embodiment shown in FIG. 12, the degassing device 261 is installed in the gas-liquid separator 211 on the anode side. However, it is also possible to use gas adding means (not shown) installed between the electrolyte container 2 and the processing container instead of the degassing device 261. [

According to the preferred embodiment of the present invention described above, the surface treatment of the bare pattern formed by partially exposing the silicon wafer coated with the oxide film can be done by using the cleaning system shown in FIG. 12, 61 and cathode water 62 may be mixed at a desired mixing ratio. As a result, the cathode water contained in the mixed cleaning solution allows the silicon substrate surface to be cleaned without generating water marks. Likewise, the anode water contained in the mixed cleaning solution removes residual impurities including metals such as copper.

As described above, the cleaning method according to any one of the first and second methods of the present invention effectively cleans the semiconductor substrate in a sufficiently simplified manner. More specifically, it is possible to reduce the number of steps required for surface treatment of a bare pattern of a semiconductor substrate coated with an oxide film. In addition, the present invention makes it possible to shorten the time required for surface treatment, reduce the number of equipment used, and simplify piping included in the processing line. In addition, the method of the present invention allows to reduce the amount of chemical used, and thus there is no need to worry about air pollution and water pollution problems.

In addition, the cleaning method according to any one of the first and second aspects of the present invention lowers equipment cost and allows high-performance semiconductor substrates to be manufactured, resulting in a reduction in the manufacturing cost of the semiconductor device.

FIG. 13 schematically shows a cleaning apparatus to which a cleaning method according to a third aspect of the present invention can be applied. FIG. As shown in the figure, the cleaning device is mainly comprised of an apparatus 301 for producing super-purified water, a pipe 401 connected to an apparatus 301 for producing super-purified water, a super-purified water supply pipe 401, A gas-liquid separating device 304 provided under the gas adding means for separating the excess gas added to the supernatant, a separating device 304, A discharge port 306 of the gas-liquid separation device for discharging the separated gas within the cleaning solution, a pipe 403 connected to the gas-liquid separation device 304 for supplying the cleaning solution with the gas added into the cleaning solution, And a surface treatment apparatus 307 of a semiconductor substrate connected to the cleaning solution supply pipe 403. [

The gas 303 applied through the valve 302 provided in the gas adding means 402 is supplied to the supercritical water purifying apparatus 301 so as to be a gas which can be dissolved in the super purified water, Is added to the supernatant supplied to the supercritical water supply pipe 401, and as a result, a cleaning solution is produced. The cleaning solution with the gas added to the cleaning solution is then supplied to the gas-liquid separation device 304 so that undesirable gas 303 is removed from the gas release port 306 through valve 305 . The cleaning solution from which an undesirable gas has been removed is applied to the surface treatment apparatus 307 through the supply pipe 403. [ The wafer 309 in the wafer holder 308 provided in the surface treatment apparatus 307 is rinsed in the surface treatment apparatus 307. [ During the cleaning process, an undesirable gas in the atmosphere is prevented from entering the cleaning solution by the lid 310 of the surface treatment apparatus 307. After the cleaning treatment, the waste cleaning solution is discharged through the waste solution pipe 311 to the outside.

It is preferable to apply the preliminary treatment to the wafer 309 disposed in the surface treatment apparatus 307 in order to obtain excellent cleaning effect without fail. More specifically, it is preferable to immerse the wafer 309 in the fluoric acid solution after putting the aqueous solution of the fluoric acid into the surface treatment apparatus 307 in advance to remove the natural oxide film from the wafer. Of course, the preliminary treatment for the removal of the natural oxide film leads to the cleaning treatment described above.

It is preferable to use hydrogen gas as the gas added to the supernatant flowing through the pipe 401. It is ideal that the hydrogen gas is dissolved in the supernatant until it reaches a supersaturated concentration. However, the hydrogen gas can function even when the hydrogen concentration of the supercritical water is at least 50 ppb. Particularly, it is preferable to dissolve hydrogen gas at a concentration of ppm digits.

Incidentally, an apparatus for producing electrolytic ionized water can be used in place of the apparatus 301 for producing a supercritical water.

A preferred gas may be used as the gas 303. In addition, when the cleaning solution inhibits the cleaning process and does not contain bubbles containing the required amount of gas, or if the position of the wafer 309 in the surface treatment apparatus 307 does not supply hydrogen gas to the wafer surface The gas-liquid separation device 304 may be omitted. In other words, although it is preferable to use a gas-liquid separation device regardless of the amount of residual hydrogen that does not dissolve in the cleaning solution, residual hydrogen is dispersed in the cleaning solution so as to be in contact with the wafer surface, Effect. It is desirable to use a valve that can regulate the amount of gas 303 at a predetermined flow rate.

After completion of the predetermined cleaning process, the waste cleaning solution is discharged through the drainage 311 of the surface treatment device 307 to dry the wafer. It is desirable to discharge the waste cleaning solution through the conductivity valve 3150 connected to the drain 311. The presence of the conductivity valve 315 may be used to increase the concentration of hydrogen dissolved in the overall cleaning apparatus, the concentration of dissolved hydrogen is in ppm digits when it is an open type of conventional cleaning apparatus that is not provided with the leads 310. However, when the conductivity valve 315 is in the drain (< RTI ID = 0.0 > 311, the dissolved oxygen concentration can be, for example, about twice that of a conventional apparatus. Needless to say, the cleaning ability is increased with an increase in the dissolved hydrogen gas concentration. Is preferably 10 < ^-3 > atmospheres, and can be preferably adjusted by the conductivity valve 315, the valve 313 and the pressure of the clean gas.

A clean gas 314 may be applied through the valve 313 into the surface treatment apparatus 307. When a clean gas is applied to the surface treatment apparatus 307, air can be prevented from entering the surface treatment apparatus 307 so as to prevent the wafer surface from being oxidized by oxygen in the air. It is preferable to use a clean gas of high purity composed of, for example, hydrogen gas, nitrogen gas or helium gas.

In order to prepare pipes, containers, etc. included in the cleaning apparatus of the present invention, it is preferable to use a material that can prevent air or the like from entering the apparatus from the outside and can ensure cleanness in the cleaning apparatus Do. Particularly, quartz, PVC (rigid polyvinyl chloride), PEEK (polyether ether ketone), PVDF (polyvinylidene fluoride), PFA (tetrafluoroethylene_perfluoroalkyl vinyl ether copolymer), PVF Fluoride) and glass comprising PTFE (polytetrafluoroethylene) is preferably used.

14 is a graph showing the cleaning effect in terms of the number of water marks remaining on the surface of the silicon wafer after the cleaning treatment. The graph covers the conventional cleaning method and the cleaning method according to the third aspect of the present invention. A silicon substrate coated with an oxide film in more detail is partially removed to form a bare pattern surrounded by the oxide film. Next, the natural oxide film is formed in the bare pattern. Under these conditions, the substrate is treated with an HF solution, followed by a normal treatment with a superscript constant, and then the substrate is dried. In this case, if 10 or more water marks are 5 5 It is found in a bare pattern of ^two sizes.

When the silicon substrate is dried immediately after the HF treatment, the water mark is not observed at all in the bare pattern of the same size. Further, when the silicon substrate is similarly treated by the method of the present invention, no water mark is observed at all or only one water mark is found in the same sized bare pattern.

Although it is not possible to remove the water mark by conventional treatment of the primary water channel, the experimental data shown in FIG. 14 shows that the particular cleaning process of the present invention is capable of removing water marks remaining on the silicon substrate without heating under vacuum or providing complicated wet processing Lt; / RTI > In fact, the amount of water marks remaining in the case of providing the cleaning method of the present invention is substantially the same as immediately after the HF treatment. In conclusion, the cleaning method of the present invention makes it possible to remove the water marks formed on the silicon substrate after the cleaning step and the water marks formed during the cleaning step and during the drying step after the cleaning step.

FIG. 15 is a schematic block diagram illustrating a modification of a cleaning apparatus that can be used to apply the cleaning method according to the third aspect of the present invention. FIG. The apparatus shown in FIG. 15 is a device shown in FIG. 15 which provides a gas discharge port 326 consisting of a gas supply port 323 and a valve 325 consisting of a valve 322 and the apparatus shown in FIG. Except that the generating device 324 is used instead of the gas-liquid separating device 304 and the gas adding means 402 included in the device shown in Fig. 13.

In the cleaning apparatus shown in FIG. 15, the supergiant water supplied from the apparatus 321 for producing the supercritical water is applied into the bubble generator 324. The preferred gas 323 is also applied via the valve 322 into the signature generator 324. As a result, bubble generation is obtained in the bubble generator 324, which makes it possible to cause the gas to dissolve in the cleaning solution more effectively than the apparatus shown in FIG. 13. Of course, an undesirable gas is discharged to the outside through the valve 325 and the gas discharge port 326. Incidentally, it is possible to use an apparatus for producing electrolytic ionized water instead of the apparatus 321 for producing a supernatant. In this case, the gas-liquid separation device needs to be used instead of the bubble generator 324 to remove undesirable bubbles.

FIG. 16 schematically illustrates another variation of a cleaning apparatus that can be used to apply the cleaning method according to the third embodiment of the present invention. The apparatus shown in FIG. 16 comprises an internal processing unit 343 and an external processing unit 344 surrounding the internal processing unit 343. As shown in the figure, the wafer retainer 341 holding the wafer 342 is disposed in the internal processing apparatus 343. Further, the cleaning solution supply pipe is connected to the internal processing device 343. In other words, the clean gas 347 is applied to the outer processing vessel 344 via the valve 346. The waste cleaning solution is discharged to the outside through the drainage 348.

The cleaning solution applied to the internal processing apparatus 343 may flow over the external processing apparatus 344. [ The wafer 342 held by the wafer holder 341 is cleaned in the internal processing container 343. [ As is apparent from the drawing, the internal processing apparatus 343 is shielded from the external atmosphere by a lead 345 that hermetically closes the open upper portion of the external processing apparatus 344 and the external processing apparatus 344. In the apparatus shown in the figure, clean gas 347 is applied to the external processing apparatus 344 via valve 346 and lead 345. Further, the waste cleaning solution containing the clean gas is discharged to the outside through the drainage 348. It is possible to use a clean gas similar to that used in the apparatus shown in FIG.

The cleaning devices shown in FIG. 16 easily reproduce the superscript constant used in the cleaning process. In addition, the apparatus is set up so that the closed separation of the cleaning solution can be easily obtained, although the degree of the closed separation obtained in the apparatus is somewhat lower than that obtained in the cleaning apparatus shown in FIG. It is understood that it is substantially preferable to use the apparatus shown in FIG. In addition, the particular design shown in FIG. 16 is suitable for preparing an automatic cleaning system.

As described above, the cleaning method according to the third aspect of the present invention makes it possible to clean the surface of the semiconductor substrate at low temperatures. It should be noted that, above all, the silicon oxide is hardly formed on the substrate surface after the cleaning process. In addition, the method of the present invention can reduce the number of processing steps required for the cleaning process. The present invention makes it possible to shorten the processing time and simplify the processing system. As a result, the number of parts included in the piping of the cleaning apparatus can be reduced.

In conclusion, the present invention provides a method for satisfactorily, easily and safely cleaning the surface of a semiconductor substrate. Of course, a high performance semiconductor device can be manufactured at low cost using the cleaning method according to the method of the present invention.

Claims (23)

A first mixed solution prepared by dissolving an acid in a superscript constant and a superscript constant in a patternless pattern formed by partially exposing a surface of a semiconductor substrate coated with an oxide film, and a second mixed solution prepared by dissolving alkali in a supersubstrate And a surface treatment step of treating the surface of the semiconductor substrate with at least one cleaning solution selected from the group consisting of a cleaning solution and a cleaning solution, wherein the final cleaning step included in the surface treatment step comprises: Wherein the cathode water has a negative oxidation-reduction potential and a pH value of 7 to 13, and the dissolved oxygen concentration in the cathode water is maintained at 300 ppb or less. The method of cleaning a semiconductor substrate according to claim 1, wherein the anode water produced by electrolysis of the cleaning solution is added to the cathode water. The cleaning method of a semiconductor substrate according to claim 1, wherein the final cleaning step is performed under an inert gas atmosphere of 10 ^-3 atmospheres containing 10 ^-6 to 100% of a gas so as to be given a reducing property. 4. The method of cleaning a semiconductor substrate according to claim 3, wherein the gas providing to impart reducibility is selected from the group consisting of hydrogen gas, hydrogen radicals having different energy states from hydrogen gas, and mixtures thereof. 4. The method of claim 3, wherein the inert gas is selected from the group consisting of nitrogen, helium, and argon. The method of claim 1, wherein the acid is selected from the group consisting of hydrochloric acid, hydrofluoric acid, sulfuric acid, and hydrogen peroxide. The cleaning method of claim 1, wherein the alkali is selected from the group consisting of ammonia water and organic alkali. A first mixed solution prepared by dissolving an acid in a superscript constant and a superscript constant in a patternless pattern formed by partially exposing a surface of a semiconductor substrate covered with an oxide film, and a second mixed solution prepared by dissolving alkali in a supersubstance And a surface treatment step of treating the surface of the semiconductor substrate with at least one cleaning solution selected from the group, wherein the final cleaning step included in the surface treatment step is a step of using a cathode water obtained by electrolyzing the cleaning solution the gas stream so that the reducing substance that provides a grant by 10 ^-6 to 100% is performed in a closed system under an inert gas atmosphere of 10 ^-3 atmospheres, including, the number of negative electrode having a negative oxidation-reduction potential of the pH-value of 7 to 13 and A method of cleaning a semiconductor substrate. The method of cleaning a semiconductor substrate according to claim 8, wherein the anode water produced by electrolyzing the cleaning solution is added to the cathode water. The method of cleaning a semiconductor substrate according to claim 8, wherein the final cleaning step is performed in a state where the oxygen concentration dissolved in the cathode water is maintained at 300 ppb or less. The method of cleaning a semiconductor substrate according to claim 8, wherein the gas providing for reductivity is selected from the group consisting of hydrogen gas, hydrogen radicals having different energy states from hydrogen gas, and mixtures thereof. 9. The method of claim 8, wherein the inert gas is selected from the group consisting of nitrogen, helium, and argon. 9. The method of claim 8, wherein the acid is selected from the group consisting of hydrochloric acid, hydrofluoric acid, sulfuric acid, and hydrogen peroxide. 9. The method of claim 8, wherein the alkali is selected from the group consisting of ammonia water and organic alkali. A first mixed solution prepared by dissolving an acid in an ultralite and a supercritical water and a second mixed solution prepared by dissolving an alkali in a supercritical water, a bare pattern formed by partially exposing a surface of a semiconductor substrate covered with an oxide film, And a surface treatment step of treating the surface of the semiconductor substrate with at least one cleaning solution selected from the group consisting of 10 ^-6 to 100% Wherein the gas stream material is generated in contact with the cleaning solution at a pressure of at least 10 < ^-3 > atmospheres, wherein the gas stream material is generated in contact with the cleaning solution A method of cleaning a semiconductor substrate. 16. The method of cleaning a semiconductor substrate according to claim 15, wherein the gas providing the reducing property is selected from the group consisting of hydrogen gas, hydrogen radicals different in energy state from hydrogen gas, and mixtures thereof. The cleaning method of semiconductor substrate according to claim 15, wherein the cathode water produced by electrolyzing the cleaning solution and having a negative oxidation-reduction potential is used as a cleaning solution in the final cleaning step. The cleaning method according to claim 17, wherein the anode water produced by electrolyzing the cleaning solution is added to the cathode water. 18. The cleaning method of claim 17, wherein the concentration of oxygen dissolved in the cleaning solution is maintained at 300 ppb or less. 16. The method of claim 15, wherein the acid is selected from the group consisting of hydrochloric acid, hydrofluoric acid, sulfuric acid, and hydrogen peroxide. 16. The cleaning method of claim 15, wherein the alkali is selected from the group consisting of ammonia water and organic alkali. Means for supplying a cleaning solution selected from the group consisting of a first mixed solution prepared by dissolving an acid in a supercritical water and a supernatant, and a second mixed solution prepared by dissolving an alkali in a supernatant. Means for applying a gaseous material containing 10 < ^-6 > to 100% of a gas so as to impart reducibility to the cleaning solution under a pressure of at least 10 < ^-3 > atm to disperse the reducibility with the cleaning solution, And a means for surface-treating the bare pattern formed by partially exposing the surface of the semiconductor substrate using a cleaning solution having a reducing-dispersing gas flow material. 23. The cleaning apparatus of claim 22, further comprising a pressing means for pressing the gas flow material so that the gas flow material is dissolved in the cleaning solution.