JP2003007671A - Apparatus and method for drying cleaned object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for drying a cleaned object, so as to suitably clean, rinse and dry substrates such as a semiconductor wafer and a glass substrate. SOLUTION: The method includes steps of etching processing over an object 50 to be cleaned by transferring of the object 50 by a transfer means to a support base 28 and into a pure water bath 20 which does not have a chemical supplied there into, supplying a chemical into the pure water bath 20 and immersing the object 50 in the chemical; rinsing over the object by supplying pure water into the bath 20, after the completion of etching operation and gradually replacing the chemical by pure water; rinsing the object 50 with use of reducing addition pure water in place of pure ware, after completion of the rinsing operation; supplying mist of an organic solvent from a nozzle 26 under the condition that the object 50 be immersed in the pure water placed in the bath 20 and also forming a sufficient thickness of layer of the organic solvent mist on a liquid surface of the pure water; and vaporizing and drying the organic solvent, after the reducing addition pure water on the surface of the object 50 is replaced by the organic solvent of the mist layer and supplying and inactive gas from a nitrogen gas supply port 24.

Description

Detailed Description of the Invention

The present invention relates to a method and a device for drying a cleaning product, and more particularly to a method and a device for drying a cleaning product suitable for cleaning, rinsing and drying a substrate such as a semiconductor wafer.

[0002]

2. Description of the Related Art Conventionally, removal of water that has entered a trench is an important factor in the drying after cleaning a precision substrate such as a miniaturized wafer, and an organic solvent vapor (vapor) is used. Drying equipment is used. As a drying device using this organic solvent paper, a device shown in FIG. 5 is known.

As shown in FIG. 5, the drying device 101 has a box-shaped drying tank 102 having an open top and a substantially U-shaped cross section.
A heating device (heater) 103 mounted on the bottom surface 102a of the drying tank 102, a cooling coil 104 provided at the upper portion of the drying tank 102, and a solution reservoir 105 provided at the lower portion of the cooling coil 104, It is composed of a wafer mounting table 107 which is placed in the drying tank 102 and on which a wafer 106 as a cleaning object is mounted, and a solution receiving section 108 which is arranged below the wafer mounting table 107.

The drying apparatus 101 heats and raises the organic solvent 109 injected into the drying tank 102 to the boiling point by the heater 103 to generate an organic solvent vapor in the upper layer, and the organic solvent 109 is washed and rinsed with water or the like. Broken wafer 106
Is inserted and placed in the drying tank 102. With respect to the wafer 106 inserted and arranged in the drying tank 102, the organic solvent is condensed on the surface of the wafer 106, and the moisture adhering to the surface of the wafer 106 is replaced with the organic solvent which is more easily evaporated, and the drying progresses. To do. The wafer 106 in the organic solvent vapor is
By gradually reaching the vapor temperature (boiling point) and being taken out of the mist atmosphere, the attached solvent component rapidly evaporates due to its low latent heat of vaporization, and the drying is completed.

Further, the organic solvent heated by the cooling coil 104 arranged in the upper part of the drying tank 102 and turned into a vapor can be condensed and dropped into the solution reservoir 105 for recovery and reuse. Similarly, the wafer 10
The solution containing the water dropped from 6 is also collected by the solution receiving unit 108.

[0006]

However, in the conventional drying device 101, since the organic solvent is heated by the heater 103, it is necessary to pay sufficient attention to the fire, and since heating and cooling are performed, energy consumption is large. Also, the heater 10
It takes time to heat by 3 to form the vapor layer, the amount of the organic solvent consumed by evaporation is large, and
When the cleaning material touches the mist layer, the heat of the vapor (gas phase) is deprived by the cleaning material, causing a rapid phase change (gas-> liquid), the vapor layer is reduced, and the cleaning material is exposed to the atmosphere. Contamination and poor drying are likely to occur.

Further, in the conventional drying apparatus 101, for example, when a substrate such as a silicon wafer is carried into the apparatus, air is mixed into the apparatus and an inert gas such as N2 is filled before drying. It is difficult to completely replace oxygen in the atmosphere, and it is impossible to completely prevent oxygen from coming into contact with the surface of the substrate until the substrate surface is completely wet with pure water and completely dried. difficult. As a result, the contact between the substrate surface and oxygen may oxidize the substrate surface to form a watermark or a natural oxide film on the substrate surface, resulting in deterioration of the contact resistance of the semiconductor device.

According to the present invention, there is no possibility that the contact resistance of a semiconductor device is deteriorated because a watermark or a natural oxide film is formed on the surface of the substrate due to the oxidation of the surface of the substrate due to the contact between the surface of the substrate and oxygen. It is possible to dry the washed items with, there is no risk of contamination of the washed items,
An object of the present invention is to provide a drying method and a drying device for a washed product without energy loss.

[0009]

A method of drying a cleaning product according to the present invention comprises a step of transferring a cleaning product into a tank to which a chemical solution is not supplied by a transfer means, and a step of supplying the chemical solution into the tank. Then, the cleaning treatment is performed by immersing the cleaning product in a chemical solution to perform etching treatment, and pure water (DIW) is supplied into the bath after completion of the etching treatment step to gradually add the chemical solution to pure water (DIW). And a rinse treatment step in which the rinse treatment step is completed, and the pure water (D
IW), rinse treatment step of rinsing the cleaning product using reducing added pure water, and pure water (DIW) in the tank
An organic solvent mist is supplied into the tank in a state where the cleaning material is immersed in the tank to form an atmosphere of the organic solvent mist, and the liquid surface of the pure water (DIW) has a sufficient thickness generated by the organic solvent mist. Forming a layer, a step of supplying an inert gas into the tank to form an inert gas atmosphere in a closed space, and the reducing additive pure water on the surface of the cleaning material is the organic solvent mist. After substituting the organic solvent in the layer produced in step 1, an inert gas is supplied to vaporize and dry the organic solvent.

Further, the gas added to the reducing-added pure water in the method for drying a washed product according to the present invention is hydrogen.

Further, the chemical liquid in the method for drying a washed product according to the present invention is DHF (HF / H ₂ O) (diluted hydrofluoric acid).

Further, in the etching treatment step of the method for drying a cleaning product according to the present invention, the cleaning product is immersed in a chemical solution for a predetermined time or a preset time.

Further, the apparatus for drying washed products according to the present invention is
Conveying means for conveying the cleaning material onto the support table in the tank to which the chemical liquid is not supplied, and supplying the chemical liquid into the tank to immerse the cleaning material in the chemical liquid to perform the etching treatment, and the etching treatment is completed. After that, pure water (DIW) is supplied into the bath to gradually replace the chemical liquid with pure water (DIW) for rinsing treatment, and after the rinsing treatment is completed, the reducing additive pure water is substituted for the pure water (DIW). Rinsing the wash with water,
An organic solvent mist is supplied into the tank in a state where a cleaning product is immersed in pure water (DIW) in the tank to form an atmosphere of the organic solvent mist, and an organic solvent is added to the liquid surface of the pure water (DIW). A layer with a sufficient thickness generated by mist is formed, an inert gas is supplied into the tank to form an inert gas atmosphere in the closed space, and reducing reducing pure water on the surface of the washed material is formed. Is replaced with an organic solvent in the layer formed by the organic solvent mist, and then an inert gas is supplied to vaporize and dry the organic solvent.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method for drying a washed product and a drying apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a drying device according to an embodiment of the present invention.

As shown in FIG. 1, the drying device 10 has a pure water tank 20 and a supply / discharge system 30 connected to the pure water tank 20.

The pure water tank 20 is supplied with pure water (D
IW) is supplied, and when the amount of pure water in the pure water tank 20 reaches a certain amount, further overflow occurs via the path of the drain valve 22b. Therefore, the vapor phase portion 23 is formed in the upper portion of the pure water tank 20. The gas phase portion 23 is provided with a nitrogen gas supply port 24 and an exhaust valve 25 that communicates with the outside air. Further, an organic solvent, that is, I in the present embodiment, is used.
A spray type nozzle 26 (hereinafter referred to as a nozzle) that forms an organic solvent mist of PA (Iso-propoxy alcohol) and radiates the mist from the tip is provided. Further, on the upper portion of the deionized water tank 20, there is provided a completely closed type opening / closing lid 27 for loading / unloading the cleaning product, and thereby a sealed space is formed. In addition, inside the pure water tank 20,
A support base 28 capable of supporting a plurality of cleaning objects 50 made of a substrate such as a semiconductor wafer is provided.
If the semiconductor wafer 8 is a semiconductor wafer, for example, the diameter is usually 8.
Although 100 inch wafers can be placed, the diameter or the number of wafers can be appropriately selected.

A drain valve 22a is provided in the center of the lower portion of the deionized water tank 20, and water is drained through this drain valve 22a. A liquid level sensor 29 is further provided in the pure water tank 20. This liquid level sensor 29
Is a sensor for lowering the descending speed of the liquid surface at around 2 to 4 mm / sec, and switching the descending speed of this liquid surface to around 1 mm / sec. The liquid supply speed of the liquid supply valve 21 and the drain valves 22a and 22b are controlled by controlling the opening and closing of the valves by a control means (not shown) such as a computer.

Next, the supply / discharge system 30 connected to the pure water tank 20 will be described. The supply / discharge system 30 includes (1) a path for supplying nitrogen gas (N ₂ ) to the nitrogen gas supply port 24,
(2) A path for supplying the organic solvent mist of IPA to the nozzle 26, and (3) a path for draining the pure water tank 20.

(1) First, the route for supplying the nitrogen gas (N ₂ ) to the nitrogen gas supply port 24 includes a heater 41 for heating the nitrogen gas (N ₂ ) and a temperature controller 42 for controlling the temperature. , A valve 43 and a filter 44. The valve 43 can be controlled to be opened / closed by a control means (not shown), and by opening / closing the valve 43, nitrogen gas (N ₂ ) is appropriately supplied into the pure water tank 20 from the nitrogen gas supply port 24.

(2) Next, the path for supplying the organic solvent mist of IPA to the nozzle 26 circulates the IPA with the IPA tank 45 storing the IPA, the IPA tank 45, the pump 46, the filter 47 and the valve 48. The circuit is constructed.
When the valve 49 is open and the valve 48 is closed,
The IPA is not circulated, and the room temperature IPA supplied from the IPA tank 45 passes through the filters 47 and 51 and the nozzle 26.
Is supplied to. At the same time, nitrogen gas (N ₂ ) at room temperature is supplied to the nozzle 26 via the filter 52. Therefore, from the nozzle 26, I
The organic solvent mist of PA is emitted. When the valve 49 is closed and the valve 48 is open, the IPA tank 45
IPA is circulated in the
8, the opening / closing control of the valve 49 is controlled by a control means (not shown).

Further, the IPA tank 45 is constantly supplied with a required amount of IPA from the IPA supply path and also with nitrogen gas (N ₂ ). This nitrogen gas (N ₂ ) is
This is to ensure safety.

(3) Further, the route for draining water from the pure water tank 20 is (a) a drain valve 22b for overflow, (b) a drain valve 22a for drain, and a route (DRAIN) for a pump 53,
(c) Exhaust path (EXH). The liquid supply valve 2
1 and the drain valve 22a are referred to as liquid supply / discharge means.

However, the drying method and the drying apparatus according to the present invention are characterized by the following points. That is, in the drying process after the rinsing process with pure water (DIW) is completed, the rinsing process is performed using hydrogenated pure water exhibiting reducibility instead of pure water (DIW).
That is, when a substrate such as a silicon wafer is dried, a very small amount of oxygen contained in the gas phase space or pure water oxidizes the substrate surface to generate a watermark or a natural oxide film. Since the hydrogenated pure water has been dissolved up to near saturation, the hydrogenated pure water exhibits a reducing property, and as a result, it has an effect of suppressing oxidation.

That is, when the dissolved oxygen contained in pure water is the cause of the formation of the watermark and the natural oxide film (when the silicon wafer is immersed in pure water), the hydrogenated pure water shows a reducing property. Suppresses the oxidation of the substrate surface. In particular,
When used in the rinsing / drying process after the treatment of an etching solution such as DHF (HF / H ₂ O) (diluted hydrofluoric acid), hydrogenated pure water exhibits a reducing property and has an effect of suppressing the oxidation of the substrate surface of the silicon wafer. At the same time, hydrogen-containing pure water has much more hydrogen atoms than normal pure water, and the substrate surface of the silicon wafer is terminated by hydrogen, that is, S.
The iH form is formed, and a stable surface state called hydrogen termination can be formed.

Further, when the silicon wafer is exposed in the air-layer space, an extremely small amount of hydrogenated pure water is present near the air-layer side where the three interfaces of the air-layer, the liquid layer and the substrate surface coexist. It exists on the substrate surface as a very small water droplet or an extremely thin water film, but since hydrogen is dissolved in this water droplet and water film to near saturation, the oxygen molecules that are present in the air space very little are dissolved in it. I can't put it in. Also, when water droplets or water films containing hydrogen gas evaporate, the substrate surface is covered with reducing hydrogen gas molecules and water molecules near the substrate surface, so oxygen atoms should directly attack the silicon wafer surface. I can't. As a result, local oxidation of the substrate surface can be prevented. Therefore, it is possible to suppress the growth of a watermark or a natural oxide film on the surface of the substrate and improve the characteristics represented by the contact resistance of the semiconductor device.

Further, the concentration of hydrogen gas volatilized from the substrate surface or hydrogen-added pure water is so thin that the concentration of dissolved hydrogen gas contained in the hydrogen-added pure water is several PPM or less, so that it fills the gas phase space. Only a very small amount of hydrogen is mixed in a mixed gas of an inert gas typified by N2 or argon or a hydrophilic gas such as IPA and an inert gas typified by N2 or argon. It has no effect.

A drying method using the apparatus for drying washed objects, which is an embodiment of the present invention having the above-mentioned structure, will be described below.

First, preparation for drying is carried out before starting the drying apparatus 10 shown in FIG. That is, the organic solvent (I
A predetermined amount of PA) is supplied from the IPA supply path into the IPA tank 45. Next, the lid 27 of the deionized water tank 20 is opened, and the cleaning object 50 such as a wafer that has been cleaned or rinsed is stored in the support base 28 by a transfer means (not shown) and placed and supported. It should be noted that the lid 27 is such that the cleaning object 50 is the pure water tank 2
When it is loaded into or unloaded from 0, it can be opened or closed automatically or manually.

Next, the drying method according to the present invention will be described with reference to FIGS. 2 is a flowchart showing the steps of the drying method according to the present invention, FIGS. 3 (a) to 3 (e) are diagrams showing the steps of DHF cleaning, and FIGS. 4 (f) to (j) are the drying methods according to the present invention. It is a figure explaining the drying process of.

As shown in FIGS. 2 and 3 (a), a cleaning product 50 such as a semiconductor wafer, which is a cleaning product, is transported into the pure water tank 20 shown in FIG. Step S1).

Next, the cleaning process (step S2)
As shown in FIG. 3B, DHF (HF / H ₂ O) prepared in advance from the liquid supply valve 21 as the liquid supply / discharge means.
A sufficient amount of (diluted hydrofluoric acid) is supplied into the pure water tank 20 for cleaning treatment. The deionized water tank 20 in this case is a tank that acts as a chemical solution tank, but is used as a deionized water tank. Therefore, it is also simply referred to as a tank.

DHF (HF) in the pure water tank 20 as a tank
/ H ₂ O) (diluted hydrofluoric acid) supply is completed,
As shown in (c), the cleaning object 50 such as the wafer is DHF.
And is subjected to an etching process. The immersion treatment, that is, the cleaning treatment is performed for a certain period of time, for example. In this embodiment, the etching process using DHF (HF / H ₂ O) (diluted hydrofluoric acid) is described by the name of the cleaning process.

When the etching process of FIG. 3C is completed, as shown in FIG. 3D, normal temperature pure water (DIW) is supplied to a predetermined amount or more from the liquid supply valve 21 as a liquid supply / discharge means. Supply and overflow, D in the pure water tank 20
HF is gradually replaced with pure water (DIW) for rinsing (step S3 shown in FIG. 2).

As described above, the cleaning process shown in FIGS. 3A to 3D and the rinse process by supplying rinse water (normal temperature) are completed.

Further, the drying method and the drying apparatus according to the embodiment of the present invention are pure water (DIW) shown in FIG. 3 (d).
In the drying process after the rinsing process by
As shown in (e), hydrogenated pure water exhibiting reducibility is used in place of pure water (DIW) (step S).
4). That is, when a substrate such as a silicon wafer is dried, a very small amount of oxygen contained in the gas phase space or pure water oxidizes the substrate surface to generate a watermark or a natural oxide film. Since hydrogenated pure water shows a reducing property because it has been dissolved to near saturation,
It has the effect of suppressing oxidation. That is, when the dissolved oxygen contained in pure water is the cause of the formation of watermarks and natural oxide films (when the silicon wafer is immersed in pure water), hydrogenated pure water shows a reducing property and shows Suppresses the oxidation of. In particular, the DHF (HF / H ₂ shown in FIG.
O) (diluted hydrofluoric acid) is used in the rinsing / drying process after the treatment, the hydrogen-added pure water shows the reducing property and has the effect of suppressing the oxidation of the substrate surface of the silicon wafer, and at the same time the hydrogen-added Compared with normal pure water, the pure water has much more hydrogen atoms, and the surface of the silicon wafer substrate is terminated with hydrogen, that is, SiH.
It is possible to form a stable surface state called hydrogen termination.

Next, as shown in FIGS. 2 and 4 (f),
When the valve 49 is opened, the room temperature organic solvent (IPA) is supplied from the IPA tank 45 to the nozzle 26, the organic solvent mist is supplied into the pure water tank 20, and at the same time, the room temperature nitrogen gas (N ₂ ) is supplied through the filter 52. Is also supplied to the nozzle 26.
An organic solvent mist is formed from the nozzle 26 by the organic solvent (IPA) at room temperature and the nitrogen gas (N ₂ ) at room temperature. As a result, an atmosphere of organic solvent mist is formed, and a layer formed by the organic solvent mist on the surface of pure water (DIW),
That is, the liquid film of the IPA layer is formed (step S
5).

Next, as shown in FIGS. 2 and 4 (g),
The supply of the organic solvent mist into the pure water tank 20 under the atmosphere of the organic solvent mist is stopped (A1 in step S6 of FIG. 2).
At the same time, the heater 41 is not operated, and nitrogen gas (N ₂ ) which is an inert gas at room temperature supplied from the temperature controller 42, the valve 43, and the filter 44 is supplied from the nitrogen gas supply port 24 into the pure water tank 20. As a result, an IPA layer having a sufficient thickness is formed on the surface of pure water (DIW) and an atmosphere of nitrogen gas (N ₂ ) is formed (A2 in step S6 in FIG. 2). Then, the exhaust valve 25 is operated to create a nitrogen gas (N ₂ ) atmosphere which is an inert gas at room temperature. Exhaust by the exhaust valve 25 is
The process is repeated until the step S8 is completed.

According to the embodiment of the present invention,
The generation of the organic solvent mist is of a spray type, but is not limited to this, and it may be generated by generating ultrasonic waves or by spraying using an ultrasonic shower type device. Good. Further, the mist particle size of the organic solvent mist according to the present embodiment is preferably 100 μm or less,
Also, stop the supply of organic solvent mist and nitrogen gas (N2)
The nitrogen gas (N2) may be supplied after a fixed time after the supply of the organic solvent mist is stopped, instead of the simultaneous control.

Next, as shown in FIGS. 2 and 4 (h),
The drain valve 22a and the pump 53 as liquid supply / discharge means are operated to discharge the pure water (DIW) in the pure water tank 20 at a high speed, and at the same time, the nitrogen gas (N2) is continuously supplied to supply the pure water (DIW). Pure water (DIW) is discharged while uniformly maintaining the liquid film of the IPA layer formed on the liquid surface (step S7 shown in FIG. 2). In addition, according to the present embodiment, by controlling the pump 53, the high speed and the low speed can be switched on the controller side (not shown).

Further, when the high speed drainage in step S7 shown in FIG. 2 is performed for a predetermined time and the state shown in FIG. 4 (i) is reached, the liquid level sensor 29 detects the liquid level and the low speed drainage process is performed. Switch to and completely discharge. Even during these drainage steps, the nitrogen gas supply port 24 supplies the nitrogen gas (N2), which is an inert gas at room temperature, to maintain the inside of the pure water tank 20 in an inert gas atmosphere, so that the wafer such as silicon (Si ) It is possible to prevent reoxidation of the surface.

Next, as shown in FIGS. 2 and 4 (j),
The heater 41 is operated to supply the heated nitrogen gas (N2) from the nitrogen gas supply port 24 into the pure water tank 20 to rapidly vaporize the organic solvent (IPA) on the surface of the wafer. And dry (step S8 shown in FIG. 2). When the above steps are completed, the cleaning object 50 such as a semiconductor wafer, which is the cleaning object in the pure water tank 20 shown in FIG.
8 is carried out from above (step S9).

As described above, according to the embodiment of the cleaning / drying apparatus equipped with the drying apparatus according to the present invention, the cleaning / drying apparatus of the one-tank type is constituted by the pure water tank 20. The one-tank type washing / drying apparatus having such a configuration can save space.

Further, in the cleaning / drying apparatus equipped with the drying apparatus according to the present invention, the IPA layer having a sufficient thickness is formed between the nitrogen gas (N2) as the carrier gas and the pure water (DIW). Even when the pure water (DIW) is drained, the liquid film is formed by the IPA layer, so that the Marangoni force is not generated and the particles are not transferred.

In the drying method according to the present invention, the nitrogen gas (N2) which is an inert gas is a gas at room temperature (step S6 in FIG. 2). This is to maintain the room temperature atmosphere. Then, as the nitrogen gas (N2) which is an inert gas for vaporizing and drying the organic solvent (IPA), a heated one is used (step S8 in FIG. 2). This is because rapid drying can be performed. According to the experimental example, the heating temperature is preferably in the range of 20 ° C to 100 ° C. But,
A non-heated material at room temperature may also be used depending on the washed product. Although nitrogen gas (N2) is used as the inert gas, argon gas may be used as the other gas. Further, according to the present invention, it is possible to suppress the adhesion of particles from the oxide film and the patterned wafer and prevent re-oxidation of the silicon (Si) surface.

The cleaning / drying apparatus equipped with the drying apparatus according to the present invention is not limited to the one-tank type cleaning / drying apparatus, and may be configured as a two-tank type three-tank type cleaning / drying apparatus.

[0046]

As described above, according to the present invention,
In the drying process after the rinsing process with pure water (DIW), hydrogenated pure water exhibiting reducibility is used instead of pure water (DIW), so that it has an effect of suppressing oxidation.

[Brief description of drawings]

FIG. 1 is a diagram including a partial cross section of a drying device according to an embodiment of the present invention.

FIG. 2 is a flow chart showing the steps of the drying method according to the present invention.

3 (a) to 3 (e) are diagrams showing a process of DHF cleaning.

4 (f) to (j) are views for explaining a drying step of the drying method according to the present invention.

FIG. 5 is a diagram showing a conventional drying device.

[Explanation of symbols]

10 Drying device 20 pure water tank 21 Liquid supply valve 22a, 22b drain valve 23 Gas Phase Department 24 Nitrogen gas supply port 25 Exhaust valve 26 nozzles 27 Open / close lid 28 Support 29 Liquid level sensor 30 supply and discharge system 41 heater 42 Temperature controller 43 valves 44 Filter 45 IPA tank 46 pumps 47 Filter 48,49 valves 50 washed items 51,52 Filter 53 pumps

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shoichi Okano             3-1-5 Sakaemachi, Hamura-shi, Tokyo Ka Corporation             In Ijo F-term (reference) 3L113 AA05 AB09 BA34 DA10 DA24                 4K057 WA01 WB06 WE07 WM14 WN01                 5F043 AA01 BB27 DD12 DD13 GG10

Claims (5)

[Claims] 1. A step of transporting a cleaning material onto a support by a transporting means into a tank to which a chemical solution is not supplied, and supplying a chemical solution into the tank to immerse the cleaning material in the chemical solution for etching treatment. And a rinse treatment step of supplying pure water (DIW) into the bath to gradually replace the chemical liquid with pure water (DIW) and rinsing after the etching treatment step is completed. After the process, the rinse treatment step of rinsing the cleaning product using reductive addition pure water instead of the pure water (DIW); and the cleaning product being immersed in the pure water (DIW) in the tank Supplying an organic solvent mist into the tank to form an atmosphere of the organic solvent mist and forming a layer having a sufficient thickness generated by the organic solvent mist on the liquid surface of the pure water (DIW); Supply inert gas inside A step of forming an inert gas atmosphere in a closed space, and supplying the inert gas after the reducing additive pure water on the surface of the cleaning material is replaced with an organic solvent in the layer generated by the organic solvent mist. And a step of vaporizing and drying the organic solvent. 2. The method for drying a washed product according to claim 1, wherein the gas added to the reducing pure water is hydrogen. 3. The chemical solution is DHF (HF / H ₂ O)
It is (diluted hydrofluoric acid), The drying method of the washing | cleaning thing of Claim 1 characterized by the above-mentioned. 4. The method for drying a washed product according to claim 1, wherein in the etching step, the washed product is immersed in a chemical solution for a certain period of time or a preset time. 5. A transport means for transporting a cleaning product onto a support table in a tank to which a chemical solution is not supplied, and a chemical solution is supplied into the tank to immerse the cleaning product in the chemical solution to perform an etching treatment. After the etching process is completed, pure water (DIW) is supplied into the bath to gradually replace the chemical liquid with pure water (DIW) to perform a rinse process, and after the rinse process is completed, the pure water (DIW) is replaced. The rinsed product is rinsed with reducing pure water, and the organic solvent mist is supplied to the tank while the rinsed product is immersed in pure water (DIW) in the tank. The atmosphere is formed and the pure water (D
IW), a layer having a sufficient thickness formed by an organic solvent mist is formed on the liquid surface, and an inert gas is supplied into the tank to form an inert gas atmosphere in the closed space. After the reducing added pure water on the surface is replaced with an organic solvent in the layer formed by the organic solvent mist, an inert gas is supplied to vaporize and dry the organic solvent to be washed. Drying device.