KR930005946B1 - Wafer cleaning method and apparatus thereof - Google Patents

Abstract

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Description

Substrate cleaning treatment method and apparatus

1 is a cross-sectional view of an apparatus for cleaning a substrate of a first embodiment of the present invention.

2 is a characteristic curve of temperature at composition under atmospheric pressure.

3 is a cross-sectional view of an apparatus for cleaning a substrate of a second embodiment of the present invention.

4 to 8 are views related to experiments performed by the present inventors, and FIG. 4 is a cross-sectional view showing an aspect of etching of a thermal oxide film.

5 is a perspective view showing the colloidal silica deposited on bar silicon around water droplets or droplets.

6 is a perspective view showing the deposition state of colloidal silica after evaporation of water droplets or droplets.

7 is an explanatory diagram of an etching progress state.

8 is an explanatory diagram of a droplet state on a silicon phase.

9 is a schematic configuration diagram of a substrate cleaning processing apparatus of a third embodiment of the present invention.

10 is a cross-sectional view of the substrate cleaning processing apparatus of the fourth embodiment of the present invention.

11 is the vapor pressure of the mixed liquid of hydrogen fluoride HF and water H ₂ O.

12 is an overall schematic longitudinal sectional view of the substrate cleaning processing apparatus of the fifth embodiment of the present invention.

13 is an enlarged longitudinal sectional view of the main part of FIG.

14 is a schematic overall sectional view of the substrate cleaning processing apparatus of the sixth embodiment.

* Explanation of symbols for main parts of the drawings

1: Storage tank 2: Stirring pump

3: piping 4: cleaning liquid supply pipe

5: on-off valve 6: liquid level meter

7,23,26: Heater 8: Cooling pipe

9: temperature sensor 10: temperature control device

11, 12, 123: solenoid valve 12: flow regulator

14: nitrogen gas supply pipe 14a: nozzle

15, 20, 262: steam generator 16: dry cleaning chamber

17: steam supply pipe 18,124: pressure sensor

19: pressure controller 20: appearance

21: pump 22: bypass piping

24 substrate processing chamber 25 mechanical chuck

26: rotating shaft 27: electric motor

28: cover 29: chamber

30: hot water supply tube 31: hot water discharge tube

32: constant temperature bath 33: aspirator

34: carrier gas supply tube 35: steam supply tube

36,255: perforated plate 37: air cylinder

38,201,251: housing 38a: carry-on

38b: outlet 39, 40, 218: substrate transfer mechanism

41,42,240,242: Exhaust pipe 60: Dry cleaning room

61: cleaning tank 62,210: all motors

63: spin chuck 64,65: nozzle

66,203: Cabarbar 67: Bare cylinder

68: pure water storage tank 69, 71, 108: pump

70: chemical storage tank 72: exhaust pipe

73: abdomen 74: gulsinam

80: cleaning chamber 101: hydrogen fluoride storage tank

102: nitrogen gas supply pipe 104,226: hydrofluoric acid supply pipe

103, 105, 110, 120: solenoid valve 106: hydrofluoric acid supply means

107: pure water storage tank 109: hand supply pipe

111: pure water supply means 112: cleaning liquid storage tank

113: stirring pump 114: pipe piping

115: concentration sensor 116, 117: level sensor

119: drain pipe 202a: bottom wall

205: inner housing 205: opening

206,252: substrate holding means 208,253: hot plate

209,254: Support shaft 211: Belt type transmission mechanism

217: pee shot 221: hot water flow path

222: hot water supply pipe 223: hot water discharge pipe

224: paid for overflow 225: automatic opening and closing valve

227,234,236 Valve 228 Steam supply passage

229: opening and closing means 235, 263: mixed gas supply pipe

239,241: flow control valve 257: hydrofluoric acid tank

The present invention provides a cleaning treatment method and a cleaning treatment for a substrate that performs etching, cleaning or dissolving or removing metal impurities on various substrates such as a semiconductor substrate, a glass substrate for a photomask, or a gram substrate for a liquid crystal display device. Relates to a device.

According to the technique disclosed in Japanese Patent Laid-Open No. 62-173720, (1) by storing a substrate in a processing chamber and (2) supplying steam of hydrofluoric acid HF into the processing chamber, the oxide film on the surface of the substrate is dissolved and then flowed downward to discharge it. After the removal of the oxide film is completed, ③ stop supplying the hydrofluoric acid vapor, supply high-purity water vapor into the processing chamber instead, wash and flow the hydrofluoric acid adhering to the substrate surface and the inner wall of the processing chamber, and completely replace it with water. After that, (4) supply of water vapor is stopped, and the substrate is dried by supplying heated nitrogen gas N ₂ to the processing chamber instead.

In this case, as a method of generating steam of hydrofluoric acid in a solution storage tank of hydrofluoric acid HF, ⓐ method of heating the reservoir tank, ⓑ boiling by injecting nitrogen gas N ₂ into the solution, ⓒ using an ultrasonic oscillator A method is disclosed.

According to this conventional example, a substrate holding means is provided in a housing, and a storage tank of hydrofluoric acid HF as a cleaning treatment liquid is provided in the lower side of the housing, and the space in the storage tank and the space in the housing are interposed therebetween. It is configured to connect with each other through a pipe provided in this manner, and to generate and supply the hydrofluoric acid HF vapor in the housing as described above to dissolve and drop the oxide film on the substrate surface.

Further, according to the technique disclosed in Japanese Patent Laid-Open No. 62-213127, (1) hydrogen fluoride obtained by heating a hydrofluoric acid anhydride while rotating a substrate housed in a processing chamber and supplying clean nitrogen gas N ₂ to the processing chamber. In addition to supplying gas HF into the processing chamber, ultrapure water (hereinafter referred to as ultrapure water), which is extremely pure in the form of fog, is introduced into the processing chamber to generate hydrofluoric acid with hydrogen fluoride gas HF and ultrapure water, and an oxide film on the substrate is formed using the hydrofluoric acid. And (3) clean the surface of the substrate by injection of ultrapure water, and (4) dry the substrate with nitrogen gas N ₂ introduced therein.

In the technique described in either Japanese Patent Laid-Open No. 62-173720 or Japanese Patent Laid-Open No. 62-213127, the high-purity water vapor is supplied to the substrate surface and the wall surface in the processing chamber before drying the substrate. In spite of the fact that the substrate is washed and flowed down by spraying ultrapure water onto the substrate, there is an unreasonable point that particles remain on the surface of the substrate.

In the technique of Japanese Patent Laid-Open No. 62-173720, an aerosol is generated together with steam by either of the method of ⓐ- © which generates steam of hydrofluoric acid HF. That is, aerosols are generated by boiling in the case of ⓐ, bubble generation in the case of ⓑ, and carburization in the case of ⓒ.

In addition, a space for installing a storage tank of hydrofluoric acid HF has to be secured to the outside of the housing, and there is a drawback of increasing the size of the entire apparatus.

In addition, as the cleaning treatment apparatus for such a substrate, it is necessary to prevent leakage of cleaning treatment vapor such as hydrofluoric acid HF to the outside, and not only the housing but also the storage tank itself, the pipe and the storage tank, and the housing, respectively. There is a need for an airtight structure for preventing leakage at the connection point, and the airtight structure is enormous, resulting in an expensive defect.

Moreover, in the technique of Japanese Patent Laid-Open No. 62-213127, supplying ultrapure water in a mist state and dissolving hydrogen fluoride gas in the mist state ultrapure water directly supplying the liquid hydrofluoric acid to the substrate is itself an aerosol. Is attached to the substrate.

It is an object of the present invention to provide a method capable of performing a highly precise substrate cleaning process with no particles remaining, and another object of the present invention is to provide a useful apparatus for carrying out the method. . Specifically, in the cleaning treatment, the aerosol is removed from the cleaning treatment vapor, and the surface of the substrate is avoided and the surface of the substrate is cleaned and the surface of the substrate is cleaned to avoid the formation of the clad silica. In addition, in the cleaning process accompanied by etching, the aerosol is removed so that the etching can be performed uniformly without impurities.

Another object of the present invention is to simplify the hermetic configuration for preventing the leakage of steam for cleaning treatment while making the whole apparatus compact.

Other objects and effects of the present invention will become apparent from the following detailed description.

In order to achieve these objectives, the present invention provides a cleaning treatment of a substrate by supplying the cleaning treatment steam to a substrate, wherein the cleaning treatment liquid is evaporated to a temperature below its boiling point, thereby generating the cleaning treatment steam generated. It is characterized by supplying to a board | substrate at the temperature exceeding the dew point, and cleaning process.

The cleaning treatment method of the substrate of the present invention includes those which have not been cleaned with the cleaning treatment liquid as in the cleaning treatment method described later. For this reason, when the film to be formed or the natural oxide film is grown, the core of the oxidation furnace, the substrate boat, the piping of the processing gas, etc. are formed of a material free of impurities, and as a processing gas, nine .9 (purity 99.999999999 In the case of using a high purity of the same or in the cleaning step before the growth of the formed film or the natural oxide film, the transfer mechanism or the chamber is formed of a material free of impurities, The particles are also formed by accumulation in a process prior to cleaning by the steam for cleaning, such as the case where a high purity is used as the liquid and transferred to the next step in a clean room under an atmosphere of high purity inert gas. If there is no metal impurity, the product of the substrate may be used without the cleaning treatment by the cleaning treatment liquid in the next step. This is because the quality does not decrease.

In addition, in the substrate cleaning processing method and substrate cleaning processing apparatus for cleaning the substrate with the cleaning treatment liquid, which will be described later, the cleaning treatment is performed with the cleaning treatment liquid in a processing chamber different from the cleaning treatment with the cleaning treatment steam. Although it is carried out, if the treatment chamber is replaced with a roughly inert gas after the washing treatment by the steam for washing treatment and the washing treatment is performed with the washing treatment liquid in a dry atmosphere containing no aerosol, colloidal silica is not produced. The substrate cleaning treatment method of the present invention also includes a case where the washing treatment with the steam for washing treatment and the washing treatment with the washing treatment liquid are performed in the same treatment chamber.

First, an experiment (determination of the cause of particle generation), consideration and a synthesis thereof will be described in order to arrive at the inventive invention.

[Experiment]

A few drops of 25% aqueous hydrofluoric acid solution is dropped on the surface of the silicon wafer with silicon thermal oxide film (th-sio ₂ ) 5,000 kPa. And the shape which the thermal oxide film is etched was observed with the optical microscope (refer FIG. 14). The etching reaction of the thermal oxide film proceeds in the vertical direction and the horizontal direction with respect to the silicon wafer.

The reaction in the vertical direction is mainly

6HF + SiO _{2 →} H ₂ SiF ₆ + 2H ₂ O ···············

I can think of it. H ₂ SiF ₆ is hexafluorofluoric acid. In addition, in particular, the occurrence of bubbles is not recognized.

The diffusion of hydrofluoric acid in the horizontal direction is rapid, and in the horizontal etching reaction, first, the thermal oxide surface layer around the liquid is corroded in scale by the mixed vapor HF / H ₂ O coming out of the droplet of hydrofluoric acid. . The response is

SiO ₂ + 4HF + 2H ₂ O → SiF ₄ + 4H ₂ O ···············

to be. SiF ₄ is silicon tetrafluoride (gas).

And, by the hydrofluoric acid extending horizontally, etching by the formula (1) is performed in the vertical direction.

㉯Next, the hydrothermal hydrofluoric acid was dropped on the surface of bare silicon by completely etching the silicon thermal oxide film by mixed steam HF / H ₂ O, and the changing shape was observed by optical microscope at every moment. See FIG. 5).

Since the surface of Na silicon is completely hydrophobic because the thermal oxide film is completely removed, it becomes hemispherical when the droplet is dropped. Observation is made for a while, and the deposition of colloidal silica SiO ₂ nH ₂ O (colloidal silicon oxide) is gradually recognized at the interface of the gaseous-liquid and gaseous-solid phases around the droplets.

The droplets gradually decrease and the colloidal silica deposited around them also increases. Isa, a relatively large float of colloidal particles is perceived in the droplets.

Colloidal silica is a fine particle of up to 0.625um. The aggregate of colloidal silica thus deposited is spotted on the surface of the silicon and forms a so-called fluoride. The deposition of colloidal silica does not occur only at the interface of each of the gaseous-liquid and gaseous-solid phases, but also on the silicon surface around the liquid reaction. As shown in FIG. 5, when a droplet of diameter d is dropped on the surface of the silicon wafer, colloidal silica is rapidly deposited at the gas-solid interface in the diameter D (D = 4d) range around the droplet. .

Also, colloidal silica is generated on the surface of the droplet, that is, the gas-liquid interface.

The incidence of colloidal silica is highest at the gaseous-solid phase interface and the gaseous-liquid phase interface and decreases as it moves away from it.

Although the cause of colloidal silica at the gas phase-solid phase interface of FIG. 5 is not clear, the colloidal silica is generated by combining water evaporating from the liquid droplet surface dropped on the wafer surface with tetrafluorosilicone in the atmosphere. I think.

The droplets gradually decrease, and with this, when colloidal silica is deposited to some extent around the droplets, and then the droplets finally disappear, large colloidal particles suspended in the droplets remain in the center. However, if the evaporation rate of the droplets is accelerated, colloidal silica is finally deposited only on the outer periphery, leaving no clade particles in the center (see Fig. 6).

The place where colloidal silica produces | generates in this way is a part which contacts the atmosphere of an etching process, and it does not generate | occur | produce in the part wetted by the droplet, ie, the liquid-solid interface.

㉰ Next, an experiment was conducted to investigate the relationship with washing with deionized water (pure water).

After removing the natural oxide film with hydrofluoric acid, water droplets of pure water were dropped on the surface of the silicon and observed under a microscope. Immediately after removal of the natural oxide film, a drop of pure water on the surface of silicon forms colloidal silica.

However, in the case of Na silicon washed while removing the natural oxide film, colloidal silica becomes difficult to form.

It is considered that the activation energy of the silicon surface is decayed by the combination of the silicon surface and various kinds of substances such as carbon in the air.

Therefore, there is a possibility that colloidal silica is formed in particular until the natural oxide film is removed by the mixed vapor HF / H ₂ O and the surface of the silicon is covered with pure water, which is considered to be a particle. .

[Review]

The formation of colloidal silica occurs in the part of the surface of the silicon contacted with the atmosphere after etching with hydrofluoric acid. In addition, it was recognized that the colloidal silica was generated around the droplets, and the incidence thereof decreased as the gas-liquid and the gas-solid phases moved away from each interface. For this reason, it turns out that generation | occurrence | production of colloidal silica has a close relationship with the moisture concentration in atmosphere. Colloidal silica, and SiO ₂ + nH ₂ O, to generate, by the treatment of hydrofluoric acid, it is considered that the generated silicon tetrafluoride SiF ₄ (gas) which is reacted with moisture in the atmosphere, such as food ③.

3SiF ₄ + 3H ₂ O → SiO ₂ ㆍ H ₂ O + 2H ₂ SiF ₆ ㆍ ··········· ③

That is, it is thought that due to the hydrolysis reaction of silicon tetrafluoride SiF ₄ (gas).

Examples of silicon tetrafluoride include those produced by the formula (2) or those produced by corrosion of vapor HF evaporated from a droplet of hydrofluoric acid or by silicon corrosion, or of hexafluorofluoric acid H ₂ SiF _{6 in} droplets. This H ₂ SiF ₄ → SiF ₄ + ₂ H ₂ O is thought to occur and decomposes, and this silicon tetrafluoride SiF ₄ and water vapor H ₂ O is thought to be a hydrolysis reaction of the formula (3) to form colloidal silica to deposit do.

Another possible cause of the formation of colloidal silica SiO _{2 n} H ₂ O is the possibility of being produced by silicon dissolved in hydrofluoric acid as in the following _formula (4).

_{^{2H + + SiF 6 2- + 6OH}} - → SiO 2 and ^{_{H 2 O + 6F - + 3H}} 2 O and and and and and and and and ④

However, the reaction of the equation (4) occurs at the gas-liquid interface, and the reaction does not reach the periphery of the droplet.

Therefore, it is thought that deposition of colloidal silica is mainly promoted by hydrolysis reaction with moisture in the atmosphere of silicon tetrafluoride generated by etching of the silicon surface by hydrogen fluoride.

In addition, colloidal silica is also promoted by droplets attached to the surface of the silicon on which the natural oxide film is removed. Therefore, when mist or aerosol adheres to the surface, it becomes a nucleus and the production of colloidal silica is promoted.

[summary]

(a) The deposition of colloidal silica is promoted by the hydrolysis reaction with moisture in the atmosphere of silicon tetrafluoride generated by etching of the silicon surface by hydrofluoric acid.

(b) The deposition of colloidal silica occurs around the droplets from which the native oxide film has been removed or adhered to the silicon surface.

(c) The deposition of colloidal silica is not recognized in the part covered with the droplets.

(d) The deposition of colloidal silica is performed by etching away the native oxide film by hydrofluoric acid, and after the silicon surface becomes hydrogen acid, and after the silicon surface is in contact with the atmosphere, until the surface is covered by deionized water. Especially occurs.

(e) The incidence of colloidal silica deposited around the droplets is highest at the interface of each of the gaseous-liquid and gaseous-solid phases, and gradually decreases as it moves away from it.

(f) In particular, colloidal silica cannot be formed on the surface of the active silicon wafer without etching and washing in succession, and the surface of the silicon is not exposed to the atmosphere.

(g) The colloidal silica has a size of about 0.625 µm, and the aggregate region is visually observed as spots of heat look.

In order to prevent the formation of colloidal silica, the aerosol (particulates) should not be included in the atmosphere of the cleaning step. For this purpose, the aerosol is not supplied to the silicon wafer and the cleaning treatment vapor supplied to the silicon wafer is liquefied. This is to avoid aerosols.

This was discovered by this experiment, and based on this finding, the means for solving the following problems were devised.

As the washing treatment liquid used in the present invention, there are various kinds of the following.

[1] sulfuric acid (H ₂ SO ₄ ), a mixture of sulfuric acid and hydrogen peroxide (H ₂ O ₂ ), fuming sulfuric acid (H ₂ SO ₄ + SO ₃ + H ₂ O ₂ ), containing sulfuric acid at a concentration of 97-98%, Sulfuric acid solution.

These vapors are effective for removing organic and inorganic substances, and in a sulfuric acid aqueous solution (H ₂ SO ₄ + H ₂ O) having a boiling point of 98.4% and a boiling point of 317 DEG C, they react with metal impurities to form sulfate. Dissolve and remove impurities.

[2] nitric acid (HNO ₃ ), fuming nitric acid (HNO ₃ + NO ₂ + H ₂ O) containing nitric acid at a concentration of at least 86%;

These vapors react with metal impurities to form nitrates, whereby metal impurities can be dissolved and removed. However, aluminum (Al), chromium (Cr) and iron (Fe) are passivated. It is also possible to oxidize the silicon surface.

[3] A mixed solution of nitric acid (HNO ₃ ) and hydrogen halide (HF, Hcl, etc.) and an aqueous solution thereof.

These vapors can be dissolved and removed by reacting with metal impurities.

In addition, particles and metal impurities can be removed by a combination of oxidation with nitric acid and oxide decomposition with hydrogen halide.

[4] Hydrogen fluoride aqueous solution (hydrofluoric acid) (HF + H ₂ O), a mixture of hydrogen fluoride (HF) and alcohol (ROH), and an aqueous solution thereof.

These vapors are effective for etching removal of the native oxide film (SiOx), react with metal impurities, become fluoride, and are dissolved and removed.

[5] A mixed solution of hydrogen fluoride (HF) and hydrogen peroxide (H ₂ O ₂ ) and an aqueous solution thereof, a mixed solution of hydrogen fluoride (HF) with alcohol (ROH) and hydrogen peroxide (H ₂ O ₂ ) and an aqueous solution thereof.

These vapors can simultaneously decompose an oxide by hydrogen fluoride fluoride on the silicon surface by hydrogen peroxide to remove particulates and metal impurities.

[6] Aqueous solution of hydrogen chloride (hydrochloric acid) (HCl + H ₂ O), a mixture of hydrogen chloride (Hcl) and alcohol (ROH), an aqueous solution thereof, a mixture of hydrogen chloride (Hcl) and hydrogen peroxide (H ₂ O ₂ ), and an aqueous solution thereof.

These vapors can react with metal impurities and dissolve and remove as chlorides.

[7] Ammonia solution (NH ₃ + H ₂ O), a mixture of ammonia (NH ₃ ) and alcohol (ROH), and an aqueous solution thereof.

These vapors can remove particles by using ammonia only to dissolve the silicon compound (etching the silicon).

[8] A mixed solution of ammonia (NH ₃ ) and hydrogen peroxide (H ₂ O ₂ ) and an aqueous solution thereof, a mixed solution of ammonia (NH ₃ ) with alcohol (ROH) and hydrogen peroxide (H ₂ O ₂ ) and an aqueous solution thereof.

These vapors can remove particles by the silicon etching action by ammonia and the oxidation action by hydrogen peroxide.

After the treatment, the surface of the substrate can be oxidized to exhibit hydrophilicity.

[9] Choline ([(CH ₃ ) ₃ NC ₂ H ₄ OH] OH) and choline derivatives ([(CnH ₂ n + l) ₄ N] 0H), aqueous choline solution ([CH ₃ ) ₃ NC ₂ H ₄ OH ] OH + H ₂ O), choline ([(CH ₃ ) ₃ NC ₂ H ₄ OH] OH) and a mixture of alcohol (ROH) and its aqueous solution.

These vapors can remove particles by silicon etching action by choline.

[10] A mixed solution of choline ([(CH ₃ ) ₃ NC ₂ H ₄ OH] OH) and hydrogen peroxide (H ₂ O ₂ ) and an aqueous solution thereof.

These vapors can remove particles by the silicon etching action by choline and the oxidation action by hydrogen peroxide. After the treatment, the surface of the substrate can be oxidized to exhibit hydrophilicity.

According to the cleaning treatment method of the substrate of the present invention, the cleaning treatment vapor supplied to the substrate by the substrate cleaning treatment is generated by evaporating the cleaning treatment liquid at a temperature below the boiling point of the cleaning treatment liquid, that is, boiling the cleaning treatment liquid. Instead of supplying the cleaning treatment vapor generated by evaporation from the surface of the cleaning treatment liquid by molecular diffusion evaporation toward the equilibrium of mass transfer of the gas-liquid phase interface, the cleaning treatment by the cleaning treatment steam is supplied. The formation of colloidal silica is prevented by the formation of aerosols by liquefaction of the steam for cleaning by preventing the formation of aerosols by liquefaction of the steam for cleaning by operating in a temperature atmosphere exceeding the dew point of the steam for treatment, i. The cause is to be blocked from the original. By evaporating the cleaning process vapor at a temperature below the boiling point, and setting the temperature of the generated cleaning process vapor to a temperature above the dew point, generation and liquefaction are prevented in the aerosol, and the substrate surface is contaminated with impurities or particles are formed. It is possible to prevent the particles carried by the aerosol from adhering to them or causing uneven etching.

Therefore, the cleaning steam for substrate cleaning can be obtained in a state without aerosol by evaporation at a temperature below the boiling point of the cleaning liquid, and furthermore, the cleaning steam in an atmosphere at a temperature exceeding the dew point. While supplying to the substrate in a liquefied state, it is possible to block the cause of the formation of colloidal silica due to the aerosol from the beginning, to improve the cleaning process of the substrate by the cleaning process steam, and to clean the substrate In addition to this, in the case of accompanied by etching, uniform etching can be performed without impurities.

In addition, in order to prevent generation of colloidal silica, it is important not to include an aerosol, and since water vapor itself is a gas, even if it is included, it does not matter.

A substrate cleaning processing apparatus of the present invention, which performs the cleaning processing method of the substrate described above, is a substrate cleaning processing apparatus including a substrate holding means for holding a substrate to be treated, wherein the substrate cleaning processing apparatus stores the cleaning liquid. The steam for the cleaning treatment in the evidence generating portion is placed on the cleaning liquid storage portion, the vapor generating portion for evaporating the cleaning liquid at a temperature below the boiling point above the cleaning liquid storage portion, and the substrate held by the substrate holding means. And a steam supply for supplying the temperature at a temperature exceeding the dew point while supplying the cleaning liquid reservoir, the steam generating unit, the substrate holding unit of the substrate holding unit, and the steam supply unit in a plan view, and at the same time up and down. It is installed in the housing close to the configuration.

More preferably, at least the substrate holding portion and the vapor supplying portion of the substrate holding means are enclosed by the inner and outer double housings, and the suction discharge amount to the inside of the inner housing is higher than the suction discharge amount to the inside of the space surrounded by the inner housing and the outer housing. It is comprised by the exhaust control means which controls a suction exhaust amount so that it may increase.

According to the cleaning processing apparatus of the substrate of the present invention, any side of the cleaning liquid storage portion, the gas generating portion, the substrate holding portion of the substrate holding means, and the vapor supply portion is provided inside the housing in a state of overlapping in the vertical direction. By the sealing structure to the housing, it is possible to seal against the external leakage of the cleaning treatment steam from the cleaning treatment liquid storage section to the steam supply section.

Therefore, any one of the cleaning liquid storage portion, the steam generating portion, the substrate holding portion of the substrate holding means, and the steam supply portion is provided inside the housing in a state of overlapping close to the vertical direction, so that the whole apparatus can be made compact. do.

In addition, since the sealing to the outside of the cleaning process vapor from the cleaning solution storage section to the steam supply section can be sealed using the sealing to the housing, the cleaning solution storage section is formed on the outside of the housing as in the prior art. It is economical because the structure for the leakage of steam is not necessary because a dedicated sealing structure for the leakage of steam is unnecessary, as in the case of installing and generating the steam for cleaning treatment.

Moreover, according to the cleaning processing apparatus of the board | substrate with which the exhaust control means was provided, the cleaning processing steam supplied to the board | substrate by the internal and external double housing is prevented from leaking to the outside, and it is the inside of discharge | emission of this cleaning processing steam. The amount of suction exhaust to the inside of the housing is controlled to be greater than the amount of suction to the inside of the space surrounded by the inner housing and the outer housing, the pressure inside the housing inside is lower than the inside of the space surrounded by the outer housing on the outside, and An atmosphere in which gas is sucked from the outside to the inside is shown to prevent leakage to the outside in the discharge of the steam for cleaning treatment.

Therefore, since the substrate holding portion and the steam supply portion by the substrate holding means are covered by the inner and outer double housings, leakage of the cleaning treatment steam supplied to the substrate to the outside can be prevented well.

Moreover, the pressure inside the inner housing is lower than the inside of the space surrounded by the outer housing outside by the suction exhaust amount, thereby preventing the discharged cleaning steam from flowing out of the inner housing from the inner housing side to the outer housing side. We can prevent leak to the outside in discharge of processing steam more surely

In order to implement the above-described cleaning treatment method of the substrate more preferably, the substrate cleaned by the above-described method is transferred to a wet cleaning treatment chamber, and the cleaning treatment liquid is supplied to the substrate for cleaning treatment.

As the cleaning treatment liquid used in the wet cleaning treatment chamber, not only pure water (deionized water) but also ammonia hydrogen peroxide solution, hydrochloric acid hydrochloric acid solution, choline or choline derivative may be used. In the cleaning treatment in the wet cleaning treatment chamber, the substrate may or may not be rotated.

According to another substrate cleaning treatment method, the substrate after the cleaning treatment by the steam for cleaning treatment is transferred to the wet cleaning treatment chamber and cleaned by the cleaning treatment liquid, thereby cleaning the cleaning treatment liquid supplied from the wet cleaning treatment chamber. Incorporation into the processing steam can be avoided, and moreover, the colloidal silica is covered by covering the entire surface of the substrate after the cleaning treatment with the cleaning treatment steam instead of supplying the cleaning treatment liquid in a mist form. Can be prevented.

Therefore, since the cleaning treatment with the cleaning treatment liquid for the substrate cleaned by the cleaning treatment steam containing no aerosol is carried out to the wet cleaning treatment chamber, mixing or cleaning treatment of the cleaning treatment liquid in the cleaning treatment steam is performed. The formation of colloidal silica by the cleaning treatment with the liquid is prevented, and even in the case where the cleaning treatment with the steam for cleaning treatment and the washing with the cleaning treatment liquid are performed in series, a substrate having a clean surface can be obtained and etching is performed. In this case, uniform etching can be performed without impurities. Therefore, even after the washing | cleaning process by washing | cleaning by steam, even if it is under the conditions which a residual particle exists, the residual particle can be removed.

The substrate cleaning apparatus of the present invention, which is preferable for carrying out such another substrate cleaning treatment method, includes a steam generator for evaporating the cleaning liquid to a temperature below its boiling point, and the steam supplied from the steam generator. Has a temperature control means for controlling the temperature to a temperature exceeding the dew point, and the dry cleaning treatment chamber is cleaned by the temperature-controlled steam for cleaning the substrate contained therein, and the cleaning treatment is completed in the dry cleaning treatment chamber. A substrate transfer mechanism for transferring the substrate, and a separation means provided in the dry cleaning treatment chamber, the supply means for supplying the cleaning treatment liquid, and storing the cleaned substrate that has been transferred by the substrate transfer mechanism, and the cleaning treatment liquid. It is configured to include a wet cleaning process chamber for supplying the substrate to clean the substrate.

According to the cleaning treatment apparatus of this substrate, the vapor generating unit is generated by evaporating the cleaning treatment liquid at a temperature lower than the boiling point of the cleaning treatment liquid, i.e., does not boil off the cleaning treatment liquid, but the equilibrium of mass transfer of the phase interface of the gas phase liquid phase. Is configured to generate cleaning steam generated by evaporating from the surface of the cleaning liquid by molecular diffusion evaporation, and the dry cleaning chamber has a temperature control means for controlling the temperature to a temperature exceeding the dew point of the cleaning steam. In order to prevent the cleaning vapor from liquefying into aerosols in the dry cleaning chamber, the dry cleaning chamber is separated from the wet cleaning chamber, and the cleaning solution supplied from the wet cleaning chamber is supplied in the dry cleaning chamber. Mixing with steam for cleaning treatment can be avoided in advance, so that Under subjected to cleaning treatment by the cleaning treatment vapor, it is prevented from the generation of the colloidal silica.

When the substrate thus cleaned is removed from the dry cleaning chamber by the substrate transfer mechanism, compounds such as silicon tetrafluoride, which may cause colloidal silica, do not leave the substrate surface and remain on one side. In addition, since the silicon tetrafluoride does not come into contact with the new substrate since it is already taken out from the dry cleaning process chamber, the substrate is exposed to colloid at this stage because the substrate is exposed to high clean air in the clean room and does not contain an aerosol. The production of silica is prevented, and in the wet cleaning treatment chamber, the cleaning treatment is performed while the entire surface of the substrate is covered with the cleaning treatment liquid, thereby preventing the formation of colloidal silica.

Therefore, the aerosol is not included in the washing steam generated in the steam generator, and the temperature of the washing steam is maintained at a temperature above the dew point by means of temperature control means, and the dry washing treatment chamber is kept in the wet washing treatment chamber. Since the separation of the cleaning treatment liquid in advance into the cleaning treatment vapor in the dry cleaning treatment chamber can be avoided, the cleaning treatment by the cleaning treatment steam can be performed under aerosol-free conditions.

In the wet cleaning process chamber, since the cleaning process is performed in a state in which the entire surface of the substrate is covered with the cleaning process liquid, generation of colloidal silica can be prevented.

By the above synergistic effect, washing with steam for washing treatment and washing with washing treatment liquid are performed in series, thereby providing a washing treatment apparatus which performs satisfactory washing treatment without generating colloidal silica.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]

1 is a cross-sectional view of a first embodiment of a substrate treating apparatus, in which 1 denotes a mixed liquid of hydrofluoric acid HF and pure H ₂ O, that is, a pseudo azeotropic washing process described later. The storage tank which stores a liquid is shown, and the piping 3 provided through the stirring pump 2 is connected over the bottom wall part and the side wall part of this storage tank 1, and is connected.

The storage tank 1 is connected to a cleaning liquid supply pipe 4 in another storage tank (not shown) that stores a pseudo azeotropic cleaning liquid (manufactured by Morita Kagaku Kouguy Co. Ltd.), and at the same time, The opening / closing valve 5 is provided in the processing liquid supply pipe 4 to open and close the opening / closing valve 5 when the storage level of the cleaning processing liquid is lower than the position detected by the liquid level gauge 6. .

In the storage tank 1, a heater 7 for heating the cleaning treatment liquid and a cooling pipe 8 for cooling the cleaning treatment liquid are provided and a temperature sensor 9 for measuring the temperature of the stored washing treatment liquid. Is installed. The temperature sensor 9 is connected to the temperature control device 10, and the solenoid valve 11 and the heater 7 provided in the temperature control device 10 and the cooling pipe 8 are connected.

In the temperature control apparatus 10, the cleaning process in the storage tank 1 is based on the detected temperature by the temperature sensor 9 while making the temperature of the cleaning process liquid stored by the stirring pump 2 uniform. The heater 7 and the solenoid valve 11 are controlled so as to have a pseudo azeotropic temperature of 30 ° C. (this temperature corresponds to a pseudo azeotropic concentration of 39.4% described below under 760 mmHg).

That is, when the temperature is lowered due to the replenishment of the cleaning treatment liquid to the storage tank 1, the power is applied to the heater 7 to heat the cleaning treatment liquid in the storage tank 9 to reach the pseudo azeotropic temperature of 30 ° C. Raise the temperature up. Conversely, when the pseudo azeotropic temperature exceeds 30 ° C, the solenoid valve 11 is opened, and the cooling water is flowed into the cooling pipe 8 to lower the temperature.

By this temperature control, to maintain the mixture in a cleaning process with liquid hydrofluoric acid HF and pure H ₂ O to a pseudo azeotropic condition, is adapted to evaporate at a temperature lower than the boiling point.

The storage tank 1 is connected to a nitrogen gas supply pipe 14 for supplying nitrogen gas N ₂ for a carrier provided with a flow regulator 12 and a solenoid valve 13, and at the end of the porous plate 1. The nozzle 14a having the () is connected to disperse and equalize the pressure in the upper steam generating part 15 in the storage tank 1.

The storage tank 1 is also connected with a steam supply pipe 17 for supplying the steam for cleaning treatment diluted with nitrogen gas N ₂ for the carrier from the steam generator 15 to the dry cleaning chamber 16.

In the storage tank 1, a pressure sensor 18 for measuring the pressure of the atmospheric gas including the steam for cleaning treatment in the steam generator 15 is provided, and the pressure sensor 18 is a pressure control device 19. At the same time, the solenoid valve 13 of the nitrogen gas supply pipe 14 is connected to the pressure control device 19 to control the opening and closing of the solenoid valve 13 based on the pressure measured by the pressure sensor 1. adjusting the feed rate of the nitrogen gas N ₂ and is configured to maintain the ambient pressure of the steam generating unit 15 in the storage tank 1 to the atmospheric pressure 760㎜Hg.

The front end side portion of the nitrogen gas supply pipe 14, the steam generator 15 of the storage tank 1, and the steam supply pipe 17 are covered with the outer wall 20 made of a heat insulating material, and the upstream portion of the outer wall 20 is provided. The downstream part is connected via the bypass pipe 22 in which the pump 21 is installed, and hot water is accommodated therein, and the heater 23 is provided in the intermediary in addition to the bypass pipe 22.

By this configuration, the hydrogen fluoride gas and the pure steam HF which circulate the hot water heated to the required temperature (for example, 50 ° C.) by the heater 23 and flow from the steam generator 15 to the steam supply pipe 17. The temperature of the steam of the cleaning solution, which is a mixed vapor of H ₂ O, is maintained at a temperature above the dew point, and in the cleaning steam in which hydrogen fluoride gas and pure steam are mixed, fluorinated under conditions of 760 mmHg and 30 ° C. The pseudo azeotropic concentration of hydrogen gas is maintained at 39.4%.

That is, the saturated steam pressure of each component of the cleaning process steam and its vapor in the atmosphere is set to be equal to or higher than the respective partial pressure to prevent condensation, that is, liquefaction, of the cleaning process steam or its respective components.

At this time, the total pressure (P _HF + P _H20 ) of the partial pressure of the hydrogen fluoride gas and the pure water vapor is 18 mmHg, and the partial pressure of nitrogen gas N ₂ is 742 mmHg.

11 is a vapor pressure diagram of a mixed liquid of hydrogen fluoride HF and water H ₂ O. Hydrogen fluoride HF is taken on the transverse side, and the vertical axis takes the voltage force, that is, the total pressure (P _HF + P _H20 ) between the partial pressure P HF of hydrogen fluoride _HF and the partial pressure P _H20 of water vapor H ₂ O), and the partial pressure using the temperature T as a parameter. The relationship between P _HF and voltage force (P _HF + P _H20 ) is shown.

The plurality of diagonal lines are straight lines indicating the respective composition ratios (mole fractions) of hydrogen fluoride to the entire mixture.

In this figure, in order to maintain the temperature of the steam generated at the pseudo-azeotropic temperature 30 ° C under the above-mentioned conditions at a temperature above 30 ° C, the mixed vapor of hydrogen fluoride gas and pure steam HF / H ₂ O is not condensed, that is, liquefied. .

On the other hand, when the concentration of hydrogen fluoride is a pseudoazeotropic concentration of 39.4% described later, the partial pressure of the mixed gas of hydrogen fluoride gas and pure steam is 18 mmHg, the partial pressure of nitrogen gas is 742 mmHg, and the whole becomes 760 mmHg. When the temperature of the steam is lower than 30 ° C, the mixed vapor of hydrogen fluoride gas and pure steam is liquefied.

In order to generate such cleaning treatment steam containing aerosol-containing hydrogen fluoride gas and pure steam, the heater 7, the cooling pipe 8, the temperature sensor 9, the temperature control device 10, and the electronics The storage tank 1 is configured by the valve 11 to maintain the temperature of the cleaning liquid at 30 ° C. and the solenoid valve 13, the nitrogen gas supply pipe 14, the pressure sensor 18, and the pressure controller 19. The steam generator 15 is configured to maintain the atmospheric pressure at 760 mmHg, and serves as a steam generator that generates steam.

Here, the pseudo cost is explained.

FIG. 2 shows the composition ratio versus temperature when the total pressure (P _HF + P _H20 ) between the partial pressure P HF of hydrogen fluoride _HF and the partial pressure P _H20 of water H ₂ O is 760 mmHg, and the horizontal axis shows hydrogen fluoride HF. The composition ratio (concentration) of [%] and vertical axis | shaft is temperature [degreeC].

In FIG. ₂ , the liquidus line and the gaseous line at 760 mmHg of the mixed liquid of hydrogen fluoride HF and water H ₂ O are in contact with each other at a temperature of 111.4 ° C. Although this is an azeotropic point, the concentration of hydrogen fluoride HF at the azeotropic point is 37.73%.

In the storage tank 1, a cleaning solution consisting of hydrofluoric acid HF having a concentration of 37.73% and pure water H ₂ O having 100-37.73 = 62.27% is stored, and the atmospheric pressure of the storage tank 1 is 760 mm. When the temperature is maintained at Hg and the temperature of the cleaning treatment liquid is kept at 111.4 ° C., the azeotropic condition is satisfied, and the composition ratio of the cleaning treatment steam is HF: H ₂ O = 37.73: 62.27 which is the same as the cleaning treatment liquid. Even if the amount of the washing treatment liquid decreases with the progress of vaporization, the composition ratio is always kept constant.

However, since the temperature of 111.4 ° C. is relatively high, it is preferable to vaporize the cleaning treatment liquid at a lower temperature in order to increase safety. If the vaporization temperature is desired to be 30 ° C., for example, the pressure (P _HF + P _H20 ) satisfying the azeotropic condition is 18 mmHg, and the concentration of hydrofluoric acid HF is 39.4%.

Although (P _HF + P _H20 ) = 18 mmHg must be reduced in pressure to make the atmosphere gas pressure, it is pseudo azeotropic that the reduced pressure is unnecessary and vaporized under an atmospheric pressure of 760 mmHg.

That is, in the storage tank 1, 39.4% of the hydrofluoric acid HF and 100-39.4 = 60.6% of pure water H ₂ O were supplied with a cleaning solution, and the heater was maintained at 30 ° C to maintain the temperature of the cleaning solution. Temperature control is performed by (7), the cooling pipe (8), the temperature sensor (9), and the temperature control device (10).

Therefore, the cleaning liquid is evaporated in the state where the atmospheric pressure in the storage tank 1, that is, the total pressure of the hydrogen fluoride gas, the partial pressures of water vapor and nitrogen gas, P _HF , P _H20 , P _N2 is 760 mmHg. do. When the atmospheric gas pressure deviates from 760 mmHg, the pressure sensor 18, the solenoid valve 13, and the pressure control apparatus 9 perform pressure regulation so that 760 mmHg may be maintained.

That is, nitrogen gas N ₂ of 760-18 = 742 mmHg powder is supplied to the storage tank 1 as an atmosphere gas and a carrier gas through the nitrogen gas supply pipe 14.

In this case, the composition ratio of the washing treatment liquid is HF: H ₂ O = 39.4: 60.6. On the other hand, if the composition ratio of the atmospheric gas is calculated,

HF: H ₂ O: N ₂ = 5.21: 8.00: 86.79

(However, the above proportional expression is expressed as HF + H ₂ O + N ₂ = 100. In the case of expression represented by HF + H ₂ O + N ₂ = 760, HF: H ₂ O: N ₂ = 7.09: 10.91: 742), which is different from the composition ratio of the cleaning liquid.

However, what is important in the cleaning process of the substrate (W), not the composition ratio in the entire atmosphere gas, the composition ratio of HF and from the hydrogen fluoride gas and water vapor H O _1. This composition ratio is

HF: H ₂ O = 5.21: 8.00 = 39.4: 60.6

(Also, in the case of the expression HF + H ₂ O + N ₂ = 760, HF: H ₂ O = 7.09: 10.91 = 39.4: 60.6)

This coincides with the composition ratio in the cleaning liquid. This is a pseudo expense.

Therefore, the steam composition ratio for the cleaning treatment supplied to the dry cleaning processing chamber 16 described later is always kept constant. In addition, the steam for cleaning treatment can be generated at a low temperature of 30 DEG C, which is atmospheric pressure, and the safety is high and there is no need for reduced pressure.

More importantly in the present invention, in order to evaporate the cleaning treatment liquid at a temperature below the boiling point of the cleaning treatment liquid, it is evaporated from the liquid surface without boiling the cleaning treatment liquid, so that no aerosol is generated.

Next, the structure of the dry cleaning process chamber 16 is demonstrated.

In a cylindrical substrate processing chamber 24 having a bottom surface, a mechanical chuck 25 for horizontally rotating a substrate such as a semiconductor wafer is provided. The chuck holding the substrate W, such as a wafer, is not limited to the mechanical chuck but may be a vacuum suction chuck of the known art.

Moreover, the chuck which built-in the heating means which heats a board | substrate at a required temperature may be built-in, vacuum suction. The electric motor 27 is interlocked with the rotary shaft 26 of the mechanical chuck 25, and is configured to drive and rotate the substrate W held by the mechanical chuck 25 around the vertical axis.

The cup-shaped lid 28 covering the upper opening of the substrate processing chamber 24 has a taper circumferential wall portion and a ceiling integrated with the chamber 29 integrated with the water sealed at the bottom thereof and the water sealed at the top. Consists of plates. The hot water supply tube 30 and the hot water discharge tube 31 for keeping the hot water at a constant temperature (for example, 50 ° C.) at all times inside the lid 28 are connected to the tapered main wall part, It consists of the constant temperature bath 32 which keeps an internal temperature at a fixed temperature.

An aspirator 33 is installed inside the constant temperature bath 32, and the hydrogen fluoride gas HF, pure steam H ₂ O, and nitrogen gas N ₂ are mixed in the aspirator 33 for etching and cleaning the surface of the substrate W. a carrier gas supply tube 34 and the steam supply tube 35 for supplying a cleaning treatment vapor in the chamber 29 to the steam supply pipe 17 for supplying the cleaning process steam and supplies the nitrogen gas N ₂ as a carrier gas connecting the carrier gas N pressure unit (負) generated by a flow of the _second cleaning the suction of steam for the cleaning process by (the negative pressure is referred to), diluted with dilute the cleaning process steam as a carrier gas N ₂ It is configured to supply the processing steam to the chamber 29.

The steam supply pipe 17, the aspirator 33, and the steam supply tube 35 are inserted into the constant temperature bath 32 in order to control the temperature of the steam for cleaning at a temperature above the dew point and to generate the liquid and its aerosol. It is to prevent. In this sense, the exterior 20 for controlling temperature on the storage tank 1 side of the cleaning solution of the constant temperature bath 32 and the steam supply pipe 17, the pump 21, the bypass pipe 22, and the heater. The configuration of 23 corresponds to the temperature control means in the configuration of the present invention.

The chamber 29 has a gas inlet inclined at an appropriate angle (for example, 30 ° C.) with respect to the radial direction at the circumferential wall thereof, and is provided with a porous plate 36 constituting the steam supply section at the lower opening.

The steam for cleaning treatment introduced from the inclined gas inlet in the chamber 29 becomes a vortex in the chamber 29, and the flow rate increases in the peripheral portion and decreases in the central portion by the centrifugal action. Therefore, in the stationary state of the mechanical chuck 25, the amount of steam outflow flow for cleaning treatment from the small hole of the porous plate 36 increases in the peripheral portion. As a result, when the substrate W held there is rotated by the rotation of the mechanical chuck 25, the air flow in the horizontal direction is generated, negative pressure is generated at the center side, and the outflow flow rate at the center side is increased. The flow rate of the outflow from the small pores of the entire surface is equalized so that the steam for cleaning treatment is uniformly supplied to the surface of the substrate W. FIG.

The cup-shaped lid 28 is configured to be able to move freely up and down with the chamber 29 so as to contact the upper edge packing of the substrate processing chamber 24 by lowering to hermetically seal the substrate processing chamber 24. A lifting air cylinder 37 is provided as a mechanism for moving the lid 28 up and down.

The main processing part made of the cup-like cover 28 etc. of the substrate processing chamber 24 demonstrated above is covered by the housing 38, and has a double-chamber structure. At a position corresponding to the position of the height of the mechanical chuck 25, the inlet 38a and the outlet 38b of the substrate are formed in the housing 38 so as to be opened and closed by a shoter not shown.

Outside of the housing 38, a cubic female substrate transfer mechanism 39 is provided at a position close to the carrying inlet 38a, and at the same time, a substrate transfer mechanism of a cusp female type is provided at a position close to the carrying out opening 38b. 40 is provided and the substrate W is raised through the inlet 38a while the lid 28 is lifted up and the substrate processing chamber 24 is opened. At the same time, the substrate W is moved to the mechanical chuck 25 and placed thereon, and the substrate W is removed from the housing 38 to the outside through the discharge opening 38b from the mechanical chuck 25. Consists of. These board | substrate conveyance mechanism structures are disclosed by Unexamined-Japanese-Patent No. 60-176548, for example.

41 denotes an exhaust pipe of the substrate processing chamber 24 and 42 denotes an exhaust pipe of the housing 38.

Next, operation | movement of the board | substrate cleaning processing apparatus of the said structure is demonstrated.

In the dry cleaning process chamber 16, the hot water supply tube 30 supplies hot water at a constant temperature (50 ° C), and discharges hot water cooled by heat exchange from the hot water discharge tube 31 to provide a constant temperature bath 32. The temperature inside is kept constant.

Opening of the inlet 38a, the air cylinder 37 is extended to raise the lid 28, and the space for allowing the substrate transfer mechanism 39 to enter between the lid 28 and the mechanical chuck 25. To secure. Then, the substrate W is held and suctioned in a vacuum to hold the substrate W, and the substrate transfer mechanism 39 extends and drives the substrate W into the housing 38 from the inlet 38a. After transferring to the mechanical chuck 25 and mounting, the substrate transfer mechanism 39 is refracted to move away from the carry-in port 38a to close the carry-in port 38a. The air cylinder 37 is shrunk so that the lid 28 is lowered, and the substrate processing chamber 24 is sealed by applying pressure to the substrate processing chamber 24.

Subsequently, by driving the electric motor 27, the substrate W is rotated together with the mechanical chuck 25. The carrier gas N ₂ is transferred to the aspirator 33 through the carrier gas supply tube 34 to generate negative pressure. Then, the hydrofluoric acid gas HF, which does not contain an aerosol, and the pure steam H ₂ O and nitrogen gas N ₂ are mixed in the steam generator 15 of the storage tank 1 through the steam supply pipe 17. The steam for cleaning treatment is sucked into the aspirator 33. Moreover, even if the suction machine 33 is not used, the cleaning steam flows into the chamber 29.

At this time, the washing process steam flowing through the steam supply pipe 17 is maintained at a required temperature exceeding the dew point of the washing process steam by hot water that is heated by the heater 23 and circulated to the pump 21, and the liquid is liquefied. Can be prevented, and the steam for cleaning treatment flowing through the front end side of the steam supply pipe 17, the aspirator 33, and the steam supply tube 35 is discharged from the internal constant temperature bath 32 of the cup-shaped lid 28. The hot water prevents its liquefaction, thereby preventing the formation of aerosols. The cleaning vapor diluted with the carrier gas N ₂ by the aspirator 33 is supplied into the chamber 29 through the inclined gas inlet through the tube 35.

The cleaning process steam injected obliquely in the chamber 29 is vortexed in the chamber 29 and flows to the substrate W through the porous plate 36 while circulating in a state where the flow rate is higher in the peripheral portion and the flow rate is smaller as in the center portion. Supplied. The airflow toward the radially outer side is generated by the centrifugal force accompanying the rotation of the substrate W held by the mechanical chuck 25.

By appropriately determining the supply flow rate of the steam for cleaning treatment and the rotational speed of the mechanical chuck 25, a uniform air flow is generated according to the balance between the negative pressure generated by the air flow accompanying the centrifugal force and the air flow downstream from the porous plate 36. It acts on the substrate (W). Thereby, the etching process with respect to the silicon thermal oxide film in the board | substrate W can be made uniform over all surfaces, and the profile becomes flat.

In addition, by controlling the temperature at which the aerosol is not generated during the supply of the cleaning process vapor containing no aerosol, the etching of the substrate can be etched in a state in which the production of colloidal silica is cut off from the original.

When the required etching is completed, the supply of the cleaning process steam is stopped and the electric motor 27 is stopped, and the inside of the substrate processing chamber 24 and the housing 38 are exhausted through the exhaust pipes 41 and 42. Then, the air cylinder 37 is extended to raise the lid 28 to open the substrate processing chamber 24. Opening the ejection opening 38b, extending the substrate transfer mechanism 40 to accept the substrate W, and transporting the substrate W to the outside through the substrate W through the ejection opening 38b in a refractive operation. . Then, the discharge port 38b is closed.

Second Embodiment

3 is a cross-sectional view of the second embodiment, in which a wet clean processing chamber 60 is provided adjacent to the dry clean processing chamber 16, and the substrate W is transferred to the substrate transfer mechanism 40 after being cleaned by steam for cleaning treatment. It is configured to carry out the cleaning treatment with the cleaning treatment liquid. The dry cleaning processing chamber 16 is as described above, and the same reference numerals are attached and the description thereof is omitted.

Next, the wet cleaning processing chamber 60 will be described.

In the cleaning process tank 61, pure water H ₂ O is sprayed onto the spin chuck 63 driven and rotated by the electric motor 62 and the substrate W while the substrate W is adsorbed and held. The nozzle 64, the nozzle 65 for injecting the cleaning chemical liquid, and a cover 66 for preventing the sprayed pure water or the chemical liquid from splashing and smoothly flowing downward, are provided, and the thin-processing tank 61 is provided. The air cylinder 67 which raises and lowers the cover 66 is provided in the lower part of (). The nozzles 64 and 65 are each comprised of a rod-shaped capillary nozzle.

The configuration of one nozzle 65 for spraying pure water H ₂ O nozzle 64 and the cleaning chemical liquid for injecting to the substrate (W), corresponds to the supply means of the cleaning treatment solution referred to in the claims.

68 is a pure water storage tank, 69 is a pump, 70 is a chemical storage tank, 71 is a pump, 72 is an exhaust pipe, 73 is a drain pipe, and 74 is a rolling female substrate transfer mechanism. As the cleaning treatment liquid, a mixed solution of pure water and the cleaning chemical liquid is used. As the cleaning liquid, ammonia hydrogen peroxide water, hydrochloric acid hydrochloric acid water, choline or choline derivatives and the like can be selected and used.

According to this second embodiment, the silicon tetrafluoride which causes the generation of colloidal silica while being carried out to the wet cleaning process chamber 60 after being carried out to the outside of the dry cleaning process chamber 16 after the etched substrate W is carried out. , SiF ₄ is volatilized on the surface of the substrate W, while placing the substrate W does not contain an aerosol in a clean room with high cleanliness, so that generation of colloidal silica is prevented.

In addition, the dry cleaning processing chamber 16 is separated from the wet cleaning processing chamber 60, so that the dry cleaning processing chamber 16 becomes a cleaning liquid image particle injected into the wet cleaning processing chamber 6 and cannot enter the substrate processing chamber 24.

Therefore, good etching can be performed without residual adhesion of particles.

[action]

Next, in this second embodiment, the operation in the wet cleaning processing chamber 60 will be described.

In the wet cleaning process chamber 60, the substrate after having been cleaned with steam for cleaning treatment in the dry cleaning process chamber 16 by opening the inlet 61a while the cover 66 is lowered due to the contraction of the air cylinder 67. (W) is moved and placed on the spin chuck 63 by the substrate transfer mechanism 40, and the substrate transfer mechanism 40 is sent out to close the delivery port 61a. Then, the air cylinder 67 is extended to raise the cover 66. First, the pump 70 is driven to supply a cleaning chemical such as choline to the substrate W from the nozzle 64 to perform primary cleaning. Then, the pump 69 is driven to supply pure water from the nozzle 64 to the substrate W for secondary cleaning.

In this case, the nozzles 64 and 65 are rod-shaped capillary nozzles, and the entire surface of the substrate W and the silicon surface can be covered with chemical liquid and pure water at once, thereby preventing the formation of colloidal silica.

The cover 66 smoothly promotes the flow of the cleaning solution downward, and prevents water droplets or droplets from remaining in the cover 66, and drainage of the cleaning solution is well discharged through the drain tube 73. This prevents the liquid from remaining in the cleaning treatment tank 61. In addition, the substrate W is covered with the cover 66 to prevent the fine particles on the inner wall surface of the cleaning tank 61 from adhering to the substrate W. As shown in FIG.

After the required cleaning is finished, the inside of the cleaning tank 61 is exhausted through the exhaust tube 72, and the spin chuck 63 is rotated at a high speed, thereby causing the cleaning solution attached to the substrate W to be blown out. (W) is dried.

When the drying is completed, the cover 66 is lowered and the cleaned substrate W is taken out of the tank by the substrate transfer mechanism 74 through the discharge port 61b.

In addition, in a time when the substrate W is not cleaned, there is a fear that bacteria causing particles may occur in the pure water in the nozzle 64 and the pipe connected to the nozzle, so that the pure water always flows out of the nozzle 64. It is desirable to prevent the development of bacteria.

In the first and second embodiments, the cleaning treatment and the drying treatment of the substrate W may be provided along the dedicated drying treatment chamber in the same treatment chamber 60.

Incidentally, in the first and second embodiments, the etching treatment and the cleaning treatment of the substrate W are configured to be separate processing chambers 16 and 60. However, if a complete dry state is realized after the cleaning treatment, the same treatment chamber is used. The etching treatment and the cleaning treatment may be performed at. In other words, colloidal silica is not produced if the conditions for complete drying in the etching treatment are satisfied. However, since it takes a considerable time to bring it to a completely dry state, the process chambers 16 and 60 are separated more efficiently.

In addition, the wet cleaning process chamber 60 may be configured to deposit a substrate in pure water H ₂ O, in addition to the configuration in which pure water is sprayed onto the substrate as in the cleaning treatment tank 61.

Third Embodiment

The inventors conducted an experiment to investigate the state of particulate formation due to organic contamination, apart from the previous experiment. As a result, when there was organic contamination, it turned out that removing it beforehand is very advantageous in preventing colloidal silica formation.

[Experiment]

As shown in FIG. 7, the silicon wafer W is placed in the longitudinal position, and the mixed vapor (HF / H ₂ O) consisting of hydrogen fluoride HF and pure water H ₂ O is moved from bottom to top. ), And the etching state of the silicon thermal oxide film th-SiO _{2 on} the surface of the silicon wafer was examined. The etching rate is higher on the lower side than on the upper side, so that the bare silicon is exposed. The boundary between the silicon and the thermal oxide film is raised from ab to cd, followed by eh, gf, ij, and finally the thermal oxide film disappears. The reaction at this time,

6HF + SiO ₂ → H ₂ SiF ₆ + 2H ₂ O ··············· 5

Proceed to H ₂ SiF ₆ is hexafluorofluoric acid. This process produces water (liquid). As shown in FIG. 8, the generated water gathers at the boundary between the bare silicon Si and the thermal oxide film th-SiO ₂ to form water droplets and rises as the etching progresses.

In this process, if there is organic contamination on the surface of the thermal oxide film or the etching progress direction is not constant, some thermal oxide films remain in the island shape and water droplets remain at the boundary between the island-shaped thermal oxide film and the silicon.

The remaining water droplets contain hexafluorofluoric acid H ₂ SiF ₆ ,

H ₂ SiF ₆ → SiF ₄ + SHF ·····················

3SiF ₄ + 4H ₂ O → SiO ₂ ㆍ 2H ₂ O + 2H ₂ SiF ₆ ㆍ ·········· ⑦

And react to form colloidal silica SiO ₂ .2H ₂ O on the silicon around the water droplets.

Therefore, in order to prevent the formation of colloidal silica, it is necessary to pay attention to removal of organic contamination on the surface of the thermal oxide film and fixation of the etching progress direction.

In the first embodiment, the mixed vapor is introduced from the gas inlet inclined with respect to the chamber 29 so that the flow rate from the porous plate 36 is increased in the peripheral portion and at the same time balanced with the mechanical chuck 25. The air flow in the horizontal direction is generated by the rotation of the held substrate W, so that the air pressure increases toward the side away from the center of rotation of the substrate W. As a result, the flow rate of the outflow from the porous plate 36 is increased by the surface of the substrate W. The etching progress direction can be constant by making it evenly distributed over the whole surface. Therefore, the problem is organic contamination.

Removal of organic contamination finds that cleaning by ultraviolet irradiation and ozone supply is effective.

Here, as the third embodiment, as shown in FIG. 9, the substrate transfer mechanism 39 is inserted to face the dry cleaning processing chamber 16 of the first embodiment, and the ultraviolet / ozone UV / O ₃ cleaning chamber 80 is provided. ), And a substrate transfer mechanism 81 for carrying the substrate W into the ultraviolet ozone UV / P ₃ cleaning chamber 80 was installed.

82 is an ultraviolet lamp as an ultraviolet irradiation means, 83 is an ozone injection nozzle as an ozone injection means, 84 is a spin chuck as a substrate holding means, and 85 is an electric motor.

Other configurations are the same as those of the first and second embodiments.

The organic contamination is removed from the substrate W in the UV / O ₃ cleaning chamber 80 before the substrate W is loaded into the dry cleaning chamber 16. Thereby, island-like water droplets do not remain on the silicon surface due to organic contamination, and the formation of colloidal silica can be prevented in the etching cleaning process.

Fourth Embodiment

The fourth embodiment is for preparing a cleaning solution made of hydrofluoric acid HF having a concentration of 37.73% and pure water H ₂ O at 100-37.73 = 62.27%.

FIG. 10 is a sectional view of the fourth embodiment, and is a hydrofluoric acid storage tank 101 containing an aqueous solution of hydrofluoric acid HF having a commercial concentration of 50% as hydrogen halide for cleaning treatment, and fluorinated in the hydrofluoric acid storage tank 101. FIG. A nitrogen gas supply pipe 102 and a valve 103 for pumping nitrogen gas N ₂ for delivering hydrogen acid, a hydrofluoric acid supply pipe 104 for supplying hydrofluoric acid, and an electromagnetic valve interposed in the hydrofluoric acid supply pipe 104. The hydrofluoric acid supply means 106 is constituted by 105.

In addition, a pure water storage tank 107 containing pure water H ₂ O, a pump 108 for pumping pure water from the storage tank 107, a pure water supply pipe 109 for supplying pure water, and this pure water The pure water supply means 111 is constituted by the solenoid valve 110 interposed in the supply pipe 109.

A cleaning liquid storage tank 112 for storing hydrofluoric acid HF and pure water H ₂ O and storing the mixed cleaning liquid is installed, and the hydrofluoric acid supply pipe 104 is installed in the cleaning liquid storage tank 112. And a pure water supply pipe 109 are connected.

In addition, the bypass pipe 114 provided with the stirring pump 113 is connected to the cleaning liquid storage tank 112, and is configured to stir-mix hydrogen fluoride acid HF and pure water H ₂ O.

The cleaning liquid storage tank 112 further includes a concentration sensor 115 such as a conductivity meter or an ultrasonic concentration meter for detecting the concentration of the cleaning liquid stored therein, an upper level sensor 116, and a lower level sensor ( 117 is provided, each of the concentration sensor 115, the upper level sensor 116 and the lower level sensor 117 is connected to the supply control device 118, and to the supply control device 118, a hydrofluoric acid supply pipe ( The solenoid valve 105 of 104, the solenoid valve 110 of the pump 108 and the pure water supply pipe 109, and the solenoid valve 120 provided in the drain pipe 119 of the washing | cleaning liquid storage tank 112 are The hydrofluoric acid in the cleaning solution stored in the cleaning solution storage tank 112 is controlled by controlling the supply amount of hydrofluoric acid HF and pure water H ₂ O at the concentrations detected by the concentration sensor 115 in these configurations. The concentration control means 121 is configured to maintain the concentration of HF at a pseudoazeotropic concentration of 39.4% (this value is an example).

That is, pressure is applied to the hydrofluoric acid storage tank 101 by opening the solenoid valve 103 and transferring nitrogen gas N ₂ through the nitrogen gas supply pipe 102. At this time, the solenoid valve 105 is open, and the hydrofluoric acid HF is supplied to the cleaning liquid storage tank 112 through the hydrofluoric acid supply pipe 104. When the hydrofluoric acid HF reaches the lower level sensor 117, the replenishment control device 118 closes the solenoid valve 105 to stop supply of the hydrofluoric acid HF, and then closes the solenoid valve 110 and simultaneously pumps 108 Drive the pure water H ₂ O from the pure water storage tank 107 through the pure water supply pipe 109 to the cleaning liquid storage tank 112.

Here, there is a pump 113 for stirring is driven, the hydrofluoric acid HF and pure water H ₂ O are mixed. At this time, when the concentration sensor 115 detects the pseudo azeotropic concentration of 39.4%, the replenishment control device 118 closes the solenoid valve 110 and stops the pump 108 at the same time to stop the supply of pure water H ₂ O. .

Before the concentration sensor 115 detects the pseudo azeotropic concentration of 39.4%, when the upper level sensor 116 is turned on, the solenoid valve 120 for draining is opened, and a part of the cleaning treatment liquid is discharged, and the pseudo azeotropic concentration is discharged. Feed pure water H ₂ O up to 39.4%.

Since the dilution heat is generated when the hydrofluoric acid HF and the pure water H ₂ O are mixed in the washing liquid storage tank 112, the uniform concentration is maintained throughout the washing liquid until the influence of the dilution heat is eliminated. It takes a certain time to become. After a certain period of time, the state is stabilized, and a cleaning treatment liquid having a pseudoazeotropic concentration of 39.4% can be obtained.

The cleaning treatment liquid storage tank 112 is connected to the cleaning treatment liquid supply pipe 4 described in the first embodiment.

A carrier gas supply pipe 122 for supplying nitrogen gas N ₂ as a carrier gas is connected to the cleaning liquid storage tank 112, and an electromagnetic valve 123 is provided in the carrier gas supply pipe 122.

In the cleaning liquid storage tank 112, a pressure sensor 124 for measuring the pressure in the upper space is provided.

According to this configuration, by opening the solenoid valve 12, sending a nitrogen gas N ₂ as a carrier gas to the carrier gas supply pipe 122, the cleaning process the liquid reservoir tank 112 is interposed, the cleaning the cleaning process liquid of a predetermined concentration of treatment It is sent to the storage tank 1 via the liquid supply pipe 4.

The conveying pressure at this time is made constant by controlling the opening and closing of the solenoid valve 123 by the detection pressure of the pressure sensor 124. FIG.

[Example 5]

12 is an overall schematic longitudinal sectional view showing the fifth embodiment of the substrate cleaning processing apparatus of the present invention.

This fifth embodiment is an improvement of the dry cleaning processing chamber described in the above-described embodiment, and the hydrofluoric acid tank 202 as the cleaning liquid storage portion for storing hydrofluoric acid as the cleaning liquid in the housing 201 is provided. The upper part of the hydrofluoric acid tank 202 is sealed by the cover 203, and the steam generation part 204 which produces | generates steam from hydrofluoric acid above the hydrofluoric acid tank 202 is formed.

In the lower portion of the hydrofluoric acid tank 202 and the inside of the housing 201, the inner housing 205 is provided in close contact with the downward surface of the bottom wall 202a of the hydrofluoric acid tank 202, and in the inner housing 205. And a vapor supply unit 207 for supplying hydrofluoric acid vapor between the lower surface of the bottom wall 202a and the substrate W while providing the substrate holding means 206 for holding the substrate W to be cleaned. Is installed.

The substrate holding means 206, as shown in an enlarged longitudinal sectional view of the main part of FIG. 13, has a hot plate 208 which allows driving rotation around a vertical side center and incorporates a heater (not shown). At the same time, the support shaft 209 is integrally connected to the hot plate 208 and the electric motor 210 installed outside the support shaft 209 and the housing 201 is a belt-type electric mechanism 211. It is connected to work through.

The hot plate 208 is provided with a support shaft 209 to form a vacuum suction unit 212, and is configured to vacuum suck the substrate (W). The heater embedded in the hot plate 208 is controlled by a temperature control means (not shown), so that the surface temperature of the hot plate 208 can be maintained at a temperature equal to or higher than the ambient temperature of the steam supply unit 207. Consists of.

At approximately the same level as the upper surface of the hot plate 208, openings 205a and 201a for taking out and exiting the substrate W are formed in each of the inner housing 205 and the housing 201, and the openings 205a, On each of the 201a), an opening / closing shoter 217 is provided. Then, the flexure arm type substrate transfer mechanism 218 provided on the outside of the opening 201a of the housing 201 is advanced to the upper side of the hot plate 208 so that the substrate W can be taken into and out of the inner housing 205. It is configured to.

That is, in a state where the substrate W is adsorbed and held by the substrate transfer mechanism 218, the substrate transfer mechanism 218 is carried in through the openings 205a and 201a onto the hot plate 208, and then the substrate transfer mechanism 218 is moved into the housing 201. The substrate W is sucked and held on the hot plate 208 while the shoters 217 and 217 are closed. On the other hand, when the substrate W is taken out of the housing 201, the shoters 217 and 217 are opened in the reverse order as described above, the substrate W is held by the substrate transfer mechanism 218, and the openings 205a and 201a are opened. It can be taken out of the housing 201.

The shoters 217 and 217 are configured to be opened and closed by engaging pinion gears (not shown) with rack gears (not shown) respectively formed so as to drive and rotate the pinion gears by the electric motor 217a. . As the shoters 217 and 217, any one having a configuration can be employed as long as it is possible to form the isotropic and airtight space of the substrate W.

In the hydrofluoric acid tank 202 described above, as shown in FIG. 13, the hot water pipe 219 is supported by an unillustrated hole diagram, and in the bottom wall 202a of the hydrofluoric acid tank 202, a hot water flow path is provided. A hydrofluoric acid tank 202 is formed by circulating hot water in a circulation path from the hot water supply pipe 222 shown in FIG. 12 to the hot water discharge pipe 223 through the hot water pipe 219 and the hot water flow passage 221. It is configured to heat and evaporate hydrofluoric acid stored therein.

The heating means for heating and evaporating hydrofluoric acid by the hot water pipe 219 and the hot water flow passage 221 is configured. In the figure, S1 shows a temperature sensor for measuring the hydrofluoric acid temperature in the hydrofluoric acid tank 202, and adjusts the amount of hot water flowing in the hot water pipe 219 and the hot water flow passage 221 to the measured temperature. The temperature of is kept at a temperature below the boiling point.

In addition, in the case of using a cleaning solution having a low boiling point, the hot water pipe 219 may be omitted, and heating of the cleaning treatment liquid and the like may be performed only by the hot water flow passage 221. It is also possible to use an oil for fruiting instead of hot water.

In the hydrofluoric acid tank 202, as shown in FIG. 12, the overflow flow path 224 is formed, and the automatic opening / closing valve 225 is provided in the middle of the overflow flow path 224. And supplying hydrofluoric acid having a concentration of 39.4% to overflow through the hydrofluoric acid supply pipe 226 in a storage tank other than the drawing, and closing the valve 227 and storing an appropriate amount of hydrofluoric acid in the overflow stage. Consists of.

The hydrofluoric acid supplied from the hydrofluoric acid supply pipe 26 is preferably heated to a predetermined temperature in advance, but the hydrofluoric acid is provided by arranging a temperature adjusting means in the supply pipe 226 as necessary. After the appropriate amount of hydrofluoric acid is stored, the automatic switching valve 225 is closed to prevent the hydrofluoric acid vapor from leaking through the overflow passage 224 during the cleaning process.

The hydrofluoric acid supplied from the hydrofluoric acid supply pipe 26 is preferably heated to a predetermined temperature in advance, but the hydrofluoric acid is provided by arranging a temperature adjusting means in the supply pipe 226 as necessary. After the appropriate amount of hydrofluoric acid is stored, the automatic switching valve 225 is closed to prevent the hydrofluoric acid vapor from leaking through the overflow passage 224 during the cleaning process.

Replenishing in the middle of the washing process is performed at an appropriate time based on the number of sheets of the substrate W and the processing time. As a configuration for supplying an appropriate amount of hydrofluoric acid in the hydrofluoric acid tank 202, for example, a liquid level meter is placed in the hydrofluoric acid tank 202 to detect that the amount of hydrofluoric acid has been reduced to a set amount, and accordingly, You may supply.

In addition, the steam supply passage 228 is opened so as to communicate with the steam generator 204 at a position higher than the position where the overflow passage 224 meets, and the end of the steam supply passage 228 is hydrofluoric acid. Opening and closing means 229 is provided to automatically open and close the steam supply passage 228 while opening the steam supply portion 207 from the downward side of the tank 202.

On the upper side of the steam generator 204 described above, a carrier gas supply pipe 233 for supplying nitrogen (N ₂ ) gas as a carrier gas is connected in communication, and a valve 234 is mounted on the carrier gas supply pipe 233. The hydrofluoric acid vapor is accumulated in the steam generator 204 by heating and is sent to the steam supply pipe 228.

A mixed gas supply pipe 235 communicating with the steam supply unit 207 and supplying nitrogen N ₂ gas as a gas for mixing is connected in communication, and a valve 236 is interposed in the mixed gas supply pipe 235. have.

Although not shown, each of the carrier gas supply pipe 233 and the mixed gas supply pipe 235 is provided with temperature control means for maintaining the temperature of the nitrogen N ₂ gas flowing therein at the set temperature.

The vapor supply unit 207 is formed by forming a vapor space 238 between the bottom wall 202a of the hydrofluoric acid tank 202 by the porous plate 237 for diffusion supply, and the vapor space 238. The vapor supply path 228 is connected in communication with each other, and the hydrofluoric acid vapor is supplied to the surface of the substrate W on the hot plate 208. The steam supply section 207 is heated to a temperature at which the temperature of the hydrofluoric acid vapor exceeds the dew point by heating by the hot water flow passage 221 formed in the bottom wall 202a of the hydrofluoric acid tank 202 and heating from the hot plate 208. It is supposed to be maintained.

According to the above-described configuration, the hydrofluoric acid tank 202, the steam generator 204, the steam supply unit 207, and the steam air blower 228, which communicates the steam generator 204 and the steam supply unit 207, are moved upward and downward. Since it arrange | positions and connects them, it can collectively control heating temperature efficiently, and it is possible to easily prevent the dew formation of the steam for washing process to them.

As shown in FIG. 12, the first exhaust pipe 240 mounted through the first flow control valve 239 is connected to the inner space of the inner housing 205 in communication with the inner housing 205 and the inner housing. A second exhaust pipe 242 is provided in communication with a space enclosed by 201 via a second flow control valve 241. Each of the first and second exhaust pipes 240 and 242 is connected to the suction exhaust device in the drawing, and the opening degree of the first flow control valve 239 is set to be larger than that of the second flow control valve 241. The suction exhaust volume is controlled so that the suction exhaust amount to the inside of the inner housing 205 is greater than that to the inside of the space surrounded by the inner housing 205 and the outer housing 204, and is discharged after being supplied to the substrate W. Exhaust control means are configured to prevent leakage of hydrofluoric acid vapor to the outside.

Furthermore, in order for the inner housing 205 to have a larger displacement than that of the outer housing 201, the diameter of the exhaust pipe 240 is larger than that of the exhaust pipe 242, and at the same time, both exhaust pipes 240 and 242 communicate with the same suction exhaust system. The structure to connect, the structure which connects the exhaust pipes 240 and 242 to another suction exhaust apparatus, etc. can be employ | adopted.

Sixth Embodiment

14 is a longitudinal sectional view showing the sixth embodiment, and substrate holding means 252 is provided for holding the substrate W by vacuum suction in the housing 251. FIG.

The substrate holding means 252 is configured to extend the support shaft 254 upward from the hot plate 253 and is installed in the housing 251 so that the support shaft 254 can be rotated about the vertical axis. Vibration motor (M) is connected to the upper end of the shaft 254 to be interlocked.

The steam supply part 256 by the porous plate 255 is provided below the board | substrate W holding part by the hot plate 253.

The bottom side of the housing 251 is formed in the hydrofluoric acid tank 257 as the cleaning liquid storage portion, and the hydrofluoric acid storage tank 260 is connected in communication with the hydrofluoric acid tank 259, while the hydrofluoric acid tank 257 is connected. ), An overflow pipe 261 is provided so that an appropriate amount of hydrofluoric acid is supplied to the hydrofluoric acid tank 257 for storage at the time of initial or replenishment.

Vapor between the hydrofluoric acid tank 257, the top and the perforated plate 255 of the generating portion 262 is formed and at the same time, supplying the nitrogen N ₂ gas to the steam generating unit 262 as a carrier gas and mixed gas The mixed gas supply pipe 263 is connected in communication.

The hydrofluoric acid temperature in the holding part of the substrate W, the steam supply part 256, the steam generating part 262 and the hydrofluoric acid tank 257 by the hot plate 253 is maintained at a temperature below the boiling point and the hot plate ( Heated at 253, the hydrofluoric acid vapor temperature for the steam generator 262 is maintained at a temperature above the dew point.

In either of the fifth and sixth embodiments, the ultraviolet / ozone cleaning chamber described in the third embodiment may be provided so as to prevent organic contamination on the substrate W. FIG.

In the said embodiment, although it is comprised so that the washing process may be carried out by rotating the board | substrate W, this invention also applies to the washing process in the state which does not rotate the board | substrate W. FIG.

In addition, all of the above embodiments have described the case where steam for cleaning treatment is generated by heating the cleaning treatment liquid. However, when the cleaning treatment liquid having a boiling point lower than room temperature is used, the same treatment can be performed by cooling the cleaning treatment liquid.

Claims (6)

A method of cleaning a substrate by supplying the cleaning process steam to the substrate, wherein the cleaning process liquid is evaporated at a temperature below its boiling point to supply the cleaning process steam generated at a temperature above the dew point to the substrate for cleaning. Process for cleaning a substrate, characterized in that the treatment. The method of cleaning a substrate according to claim 1, wherein the cleaned substrate is conveyed to a wet cleaning chamber, and the cleaning liquid is supplied to the substrate for cleaning. A cleaning processing apparatus for a substrate having substrate holding means for holding a substrate to be treated, comprising: a cleaning processing liquid storage section for storing a cleaning processing liquid, and the cleaning processing liquid above the cleaning processing liquid storage section; A steam generator for evaporating at a temperature below the boiling point and a steam supply section for supplying the cleaning steam from the steam generator to the substrate held by the substrate holding means while controlling the temperature at a temperature above the dew point; And the cleaning processing liquid storage portion, the steam generating portion, the substrate holding portion of the substrate holding means, and the steam supply portion are doubled in plan view and installed in the housing by accessing them in the vertical direction. The apparatus of claim 3, wherein the apparatus for processing a substrate covers at least the substrate holding portion and the vapor supplying portion of the substrate holding means with a double inner and outer housings, and the suction exhaust to the inner housing is surrounded by the inner and outer housings. And an exhaust control means for controlling the suction exhaust amount so as to be larger than the suction exhaust amount to the inside of the substrate. In a cleaning processing apparatus for a substrate having a substrate holding means for holding a substrate to be treated and a steam supply unit for supplying steam for cleaning treatment to the substrate held by the substrate holding means, the cleaning liquid is less than its boiling point. And a steam generator for evaporating to a temperature, and a temperature adjusting means for controlling the temperature of the steam supplied from the steam generator at a temperature exceeding the dew point, and storing the substrate housed therein in the temperature controlled cleaning steam. A dry cleaning process chamber for cleaning by means of a cleaning process, a substrate transfer mechanism for conveying a substrate which has been cleaned in the dry cleaning process chamber, and a separation means provided in the dry cleaning process chamber for supplying a cleaning treatment liquid to the substrate transfer mechanism. And a wet cleaning process chamber for storing the substrate which has been transported by the cleaning process and supplied with the cleaning treatment liquid to clean the substrate. A cleaning processing apparatus for a substrate. 6. The apparatus for cleaning a substrate according to claim 5, wherein the cleaning apparatus for the substrate includes substrate holding means for holding a substrate to be treated, ultraviolet irradiation means for irradiating ultraviolet rays to the substrate held by the substrate holding means, and substrate holding means. A substrate transfer mechanism for installing an ultraviolet / ozone cleaning chamber equipped with an ozone injection means for injecting ozone to the substrate held in the above, and transferring the substrate treated in the ultraviolet / ozone cleaning chamber to a steam supply unit. Cleaning treatment apparatus.

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