JPH06260469A - Method and device for wet-treating substrate - Google Patents

Abstract

PURPOSE:To prevent the formation of a natural oxide film on the surface of a wafer and to reduce the size of a system as a whole by housing wafers in a sealed tank of a single treatment solution and filling the tank with a plurality of kinds of treatment solutions by successively replacing older solutions with newer solutions. CONSTITUTION:After wafers W, W,... carried in from a preceding process are set in a substrate holding section in a treatment solution tank 5 manually or automatically by means of a carrying-in robot, the tank 5 is sealed. Then the wafers W, W,... are cleaned by filling the tank 5 with three kinds of cleaning solutions by successively replacing older solutions with newer solutions. For example, the wafers W, W,... are successively cleaned with HF, SC-1 solution (NH4OH+H2O2+ pure water), and SC-2 solution (HCl+H2O2+ pure water) in this order. Therefore, the wafers are cleaned by using a completely closed system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of wet processing a substrate and an apparatus therefor, and more specifically, to wet etching by dipping a thin substrate such as a semiconductor substrate or a liquid crystal glass substrate in a plurality of types of processing liquids. Technology related to continuous cleaning and cleaning.

[0002]

2. Description of the Related Art In order to maintain high performance and reliability of a semiconductor device, it is essential to reduce contaminants on the surface of a semiconductor substrate (hereinafter referred to as a wafer) as much as possible to maintain high cleanliness. From this viewpoint, various wafer cleaning processing techniques have been conventionally developed.

As a wafer cleaning method, wet cleaning using a cleaning liquid is predominant because it is suitable for batch cleaning in which a plurality of wafers are collectively processed. In this cleaning method, generally, a plurality of cleaning tanks are arranged in a high-cleanliness atmosphere chamber, and a wafer is sequentially immersed in a cleaning liquid filled in these cleaning tanks for a predetermined time by a transfer processing apparatus to perform cleaning. It is processed.

[0004]

However, such a cleaning method has the following problems.

In other words, semiconductor devices have recently entered the sub-micron era, and with the miniaturization and high integration of such device structures, very high cleanliness is required on the wafer surface. In the conventional cleaning method described above, every time the wafer is transferred from the cleaning tank to the cleaning tank, the wafer is always exposed to the cleanliness atmosphere, that is, the atmosphere, and the wafer surface comes into contact with oxygen in the atmosphere.

Then, the wafer chemically reacts with this oxygen to form a natural oxide film on the surface thereof, which not only hinders the subsequent wafer processing steps, but also
There is a problem that the reliability of the device is impaired, such as the deterioration of element characteristics.

Further, since the boundary surface between the atmosphere and the cleaning liquid, that is, the gas-liquid interface moves on the surface of the wafer when the wafer is pulled down and pulled up with respect to the cleaning liquid, contaminants such as particles existing at this interface portion are transferred to the wafer. There is also a possibility that it may adhere to the surface and cause contamination.

Furthermore, since a plurality of cleaning tanks are arranged in a row in a row and a transfer processing apparatus for immersing wafers in these cleaning tanks is indispensable, the apparatus itself becomes complicated and large, and the apparatus cost is high. There was a problem that became.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to perform a cleaning treatment step using a plurality of kinds of treatment liquids without contacting a wafer with oxygen in the atmosphere. By performing the above, it is possible to prevent the formation of a natural oxide film on the surface of the wafer, and to provide a wet processing technique for the wafer that can reduce the size of the entire system.

[0010]

In order to achieve the above object, a method of wet processing a substrate according to the present invention is a wet processing method in which a wafer is processed with a plurality of kinds of processing liquids, respectively, and a single sealed A wafer is stored in a processing liquid tank, and a plurality of types of processing liquids are sequentially replaced in the processing liquid tank while being filled and supplied for processing.

Further, the substrate wet processing apparatus of the present invention is suitable for carrying out the above-mentioned processing method, and includes a single treatment liquid tank which can be sealed and a plurality of treatment liquids in the treatment liquid tank. The treatment liquid tank is connected to the bottom of the treatment liquid tank, and the top of the treatment liquid tank is connected to the drainage pipe. A substrate holding unit for directly holding the wafer is provided in the liquid tank.

[0012]

[Function] Wafer processing in an atmosphere in which oxygen is excluded by sequentially supplying and supplying a plurality of kinds of processing liquids into the processing liquid tank while the wafers are contained and held in a single sealed processing liquid tank. To realize.

Specifically, when the preceding treatment liquid is replaced with the treatment liquid that follows, the preceding treatment liquid is extruded and eliminated while filling and supplying deionized water for washing with water and an inert gas into the treatment liquid tank. After that, the pure water is extruded and removed while filling and supplying the subsequent processing liquid into the processing liquid tank. This minimizes the contact between the wafer and oxygen and prevents the formation of a native oxide film on the wafer surface.

Further, by carrying out all the wafer processing steps in a single processing liquid tank, the size of the apparatus can be reduced.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

Example 1 A schematic structure of a wet processing apparatus for substrates according to the present invention is shown in FIG. 1. Specifically, this apparatus is a batch type cleaning apparatus for cleaning a plurality of wafers W (for example, 25 wafers) collectively. And
The treatment liquid unit 1, the liquid supply unit 2, the liquid discharge unit 3, and the control unit 4 are provided as main parts.

The processing liquid section 1 is composed of a single processing liquid tank 5 for batch-processing wafers W, W, ... And an outer tank 6 for keeping the processing liquid tank 5 warm and heating, and is not shown. However, it is placed in a clean room kept in a clean atmosphere.

The processing liquid tank 5 is a PF having a sealable structure.
It is made of A, and a liquid supply pipe 7 is connected to its bottom portion 5a, and a drainage pipe 8 and an inert gas introduction pipe 9 are connected to its top portion 5b. Although not shown, the processing liquid tank 5
A substrate holding portion for holding the wafers W, W, ...

The liquid supply pipe 7 has a plurality of liquid supply valves 10a to 10a.
A drain pipe provided with a drain valve 11 while being connected to a liquid supply unit 2 for supplying various cleaning liquids and a pure water supply source (not shown) for supplying pure water via 10d (four in the illustrated example). It is connected to a drainage part (not shown) via 11a. The drainage pipe 8 is connected to the drainage unit 3 and the drainage unit via a manual valve 12 and two switching valves 13a and 13b. Further, the inert gas introducing pipe 9 is used to push out pure water in advance when the wafers W, W, ... Are taken out and drain it. Specifically, nitrogen (N ₂ ) is introduced through the check valve 9a.

The outer tank 6 is made of PP of an upper opening type in which the processing liquid tank 5 is dipped, and the inside thereof is filled with pure water and is provided with a heater 15 for heating the pure water. Pure water is supplied from the pure water supply source through a water supply pipe 16 having a manual valve 16a. Reference numeral 17 is a sensor for preventing water heating for confirming the liquid surface of pure water, 18 is a temperature sensor for measuring the water temperature, and 19 is a drain valve provided in a drain pipe 19a connecting from the bottom portion 6a of the outer tank 6 to the drain portion. Shown respectively.

The liquid supply unit 2 supplies the processing liquid to the processing liquid tank 5 and is composed of four PFA liquid supply tanks 20a, 20b,
It is provided with 20c and 20d, and is configured to selectively supply any one of three types of processing liquids described later.

Specifically, the first liquid supply tank 20a is filled with ammonia water (NH ₄ OH + pure water), and
A heater 21a, a temperature sensor 22a, and an empty heating prevention sensor 23a for checking the liquid level are provided. Second liquid supply tank 20
b is filled with hydrochloric acid (HCl + pure water), and is provided with a heater 21b, a temperature sensor 22b, and an empty heating prevention sensor 23b for confirming the liquid level. Third liquid supply tank 2
0c is filled with hydrofluoric acid (HF + pure water) or buffered hydrofluoric acid (BHF + pure water). Further, the fourth liquid supply tank 20d is filled with hydrogen peroxide solution (H ₂ O ₂ ).

Each of the liquid supply tanks 20a to 20d is provided with a filtration circulation passage 25 composed of a circulation pump 25a and a filter 25b, and the cleaning liquid filled in these is supplied via circulation valves 26a and 26b. Filtration is carried out regularly or regularly to maintain its cleanliness.

Further, the first to third liquid supply tanks 20a-2
0c has the bottom portions of the liquid supply valves 10a to 10c, respectively.
The fourth liquid supply tank 20d is connected to the first liquid supply tank 20a and the second liquid supply tank 20d via a bypass pipe 27 at a midpoint of the filtration circulation path 25 while being connected to the liquid supply pipe 7 via the bypass pipe 27. Tank 20
respectively connected to b. Reference numerals 28a to 28c denote liquid supply valves arranged in the bypass pipe 27.

In the illustrated example, the liquid supply tanks 20a to 20d are arranged above the processing liquid tank 5 in the height direction for the purpose of simplifying and compacting the apparatus structure. Although the liquid is supplied to the processing liquid tank 5 from the above by a gravity drop method, it is also possible to adopt a forced liquid supply method using a liquid supply pump or the like (not shown).

Therefore, the supply of the processing liquid to the processing liquid tank 5 in the liquid supply part 2 is performed by using the HF liquid or the BHF liquid, SC-1 (N
H ₄ OH + H ₂ O ₂ + pure water liquid or SC-2 (HC
One of the three types of liquid (1 + H ₂ O ₂ + pure water) is selectively performed in the following manner.

That is, in the case of HF liquid or BHF liquid,
The liquid supply valves 10a, 10b and 10d are closed, and the liquid supply valve 10c is opened, whereby the HF liquid or the BHF liquid is gravity-dropped from the third liquid supply tank 20c and is supplied through the liquid supply pipe 7. It is supplied to the processing liquid tank 5.

In the case of the SC-1 liquid, first, the hydrogen peroxide solution (H ₂ O ₂ ) in the fourth liquid supply tank 20d is passed through the bypass pipe 2.
It is supplied to the first liquid supply tank 20a via 7 and mixed with ammonia water (NH ₄ OH + pure water) therein at a predetermined mixing ratio (for example, 1: 1: 5) to form an SC-1 liquid. At the same time, it is heated to a predetermined temperature (for example, 80 ° C.) by the heater 21a. Subsequently, the liquid supply valves 10b, 10c and 1
0d is closed and the liquid supply valve 10a is opened,
As a result, the SC-1 liquid is gravity-dropped from the first liquid supply tank 20a and supplied to the processing liquid tank 5 through the liquid supply pipe 7.

Further, in the case of the SC-2 liquid, like the SC-1 liquid, first, the hydrogen peroxide solution (H ₂
O ₂ ) is supplied to the second liquid supply tank 20b through the bypass pipe 27, and mixed with hydrochloric acid (HCl + pure water) therein at a predetermined mixing ratio (for example, 1: 1: 5) to produce SC-2. It becomes liquid and is heated to a predetermined temperature (for example, 8
(0 ° C). Subsequently, the liquid supply valves 10a and 10c
And 10d are closed and the liquid supply valve 10b is opened, whereby the SC-2 liquid is supplied to the first liquid supply tank 20b.
Is dropped by gravity to be supplied to the processing liquid tank 5 through the liquid supply pipe 7.

The drainage unit 3 collects the drainage from the processing liquid tank 5 and is composed of three PFA drainage recovery tanks, that is, H.
First drainage recovery tank 30a for Cl, second for NH ₄ OH
And a third drainage recovery tank 30c for HF (or BHF). In the drainage recovery tanks 30a to 30c, the drainage discharged to the drainage pipe 8 is selectively collected by the two switching valves 13a and 13b. In addition, each drainage recovery tank 30
The a to 30c are respectively provided with full sensor 31a to 31c for checking the liquid level and interlocking with an alarm buzzer (not shown).

In the illustrated example, the drainage recovery tanks 30a to 30c are arranged below the processing liquid tank 5 in the height direction for the purpose of simplifying and compacting the apparatus structure as described above. From this processing liquid tank 5 to each drainage recovery tank 30a-
Although the structure is such that the liquid is discharged to 30c by a gravity drop method, it is also possible to adopt a forced liquid discharge method using a liquid discharge pump or the like (not shown).

The control unit 4 is specifically composed of a microcomputer having CPU, ROM, RAM and the like as main components, and the processing liquid unit 1 and the liquid supply unit described above are supplied in accordance with a predetermined program for executing the following cleaning process. It is configured to automatically control the respective constituent devices of the section 2 and the drainage section 3.

Next, the cleaning process in the cleaning apparatus having the above-mentioned structure will be described.

(1) Wafers W, W, loaded from the previous process
Are manually held or automatically by a carry-in robot (not shown) to be held and stored in the substrate holding portion in the processing liquid tank 5, and then the processing liquid tank 5 is sealed.

(2) Wafers W, W, W
... is subjected to cleaning treatment. In this example, the cleaning step is performed in the order of HF solution (or BHF solution) processing → SC-1 solution processing → SC-2 solution processing.

Cleaning with HF solution (or BHF solution)
Processing: With the liquid supply valves 10a, 10b, and 10d closed, the liquid supply valve 10c is opened and the HF liquid (or B
The HF liquid) is supplied and filled from the third liquid supply tank 20c through the liquid supply pipe 7 from the bottom portion 5a of the processing liquid tank 5. After that, the liquid supply valve 10c is closed and the HF liquid cleaning is performed for a predetermined time.

Rinsing treatment with pure water: When the cleaning time with the HF liquid (or BHF liquid) is up, the liquid supply valve 10d is opened, and pure water is supplied from the pure water supply source through the liquid supply pipe 7 The HF liquid (or BHF liquid) supplied from the bottom portion 5a of the treatment liquid tank 5 is pushed out from the lower side to the upper side to the drainage pipe 8. Then, after the HF liquid (or BHF liquid) in the treatment liquid tank 5 is diluted with pure water and finally completely replaced with pure water, the washing process with this pure water is performed for a predetermined time.

On the other hand, the HF liquid (or BHF liquid) discharged to the drainage pipe 8 and the pure water following the HF liquid are respectively transferred to the switching valve 1.
It is collected in the drainage recovery tank 30c via 3a and is drained to the drainage section.

Cleaning process with SC-1 liquid : When the cleaning time with pure water is up, the liquid supply valve 10d is closed and the liquid supply valve 10a is opened. Then,
SC-1 heated and adjusted at a predetermined mixing ratio as described above
The liquid is supplied from the first liquid supply tank 20a through the liquid supply pipe 7 from the bottom portion 5a of the processing liquid tank 5, and the pure water in the processing liquid tank 5 is directed from the lower side to the upper side to the drainage pipe 8 Extrude to. Then, after the pure water in the treatment liquid tank 5 is completely replaced with the SC-1 liquid, the liquid supply valve 10a is closed and the cleaning treatment with the SC-1 liquid is performed for a predetermined time.

In this case, the pure water in the outer tank 6 is also heated by the heater 15.
Is heated to the same temperature as the SC-1 liquid (for example, 80 ° C.) to keep the SC-1 liquid in the treatment liquid tank 5 warm. On the other hand, the pure water discharged to the drainage pipe 8 and the subsequent SC-1
The liquid is drained to the drainage section via the switching valves 13a and 13b, respectively, and is collected in the drainage collection tank 30b.

Rinsing treatment with pure water: When the cleaning time with SC-1 is up, the liquid supply valve 10d is opened, and the SC-1 liquid in the treatment liquid tank 5 is discharged as in the process.
After being diluted with pure water and finally completely replaced with pure water, a washing process with pure water is performed for a predetermined time.

On the other hand, the SC-1 liquid discharged to the drainage pipe 8 and the pure water following it are collected in the drainage recovery tank 30b via the switching valves 13a and 13b, respectively, and drained to the drainage section. To be done.

Cleaning Treatment with SC-2 Liquid : When the cleaning time with pure water is up, the liquid supply valve 10d is closed and the liquid supply valve 10b is opened. Then,
SC-2 heated and adjusted at the specified mixing ratio as described above
The liquid is supplied from the second liquid supply tank 20b through the liquid supply pipe 7 from the bottom portion 5a of the processing liquid tank 5, and the pure water in the processing liquid tank 5 is pushed out to the drainage pipe 8 from the lower side. And the processing liquid tank 5
After the pure water inside was completely replaced with the SC-2 liquid, the liquid supply valve 1
0b is closed, and the cleaning process with the SC-2 liquid is performed for a predetermined time.

In this case, as in the process, the SC-1 liquid in the treatment liquid tank 5 is kept warm by the pure water (warm water) in the outer tank 6. On the other hand, the pure water discharged to the drainage pipe 8 and the subsequent S
The C-2 liquid is passed through the switching valves 13a and 13b,
The water is drained to the drainage section and is collected in the drainage collection tank 30a.

Washing treatment with pure water: When the washing time with SC-2 has timed out, the liquid supply valve 10d is opened, and the SC-2 liquid in the treatment liquid tank 5 becomes
After being diluted with pure water and finally completely replaced with pure water, a washing process with pure water is performed for a predetermined time.

On the other hand, the SC-2 liquid discharged to the drainage pipe 8 and the pure water following it are recovered to the drainage recovery tank 30a via the switching valves 13a and 13b, respectively, and drained to the drainage section. To be done.

(3) Upon completion of all the cleaning steps (2) to (5), the liquid supply valve 10d is closed and the liquid discharge valve 11 of the liquid supply pipe 7 is opened. The pure water in the treatment liquid tank 5 introduced from the active gas introducing pipe 9 through the check valve 9a from the top portion 5b of the treatment liquid tank 5 is pushed out from the upper side to the lower side.
Drain via 1 Finally, after drying the wafers W, W, ... In this nitrogen atmosphere, the sealed state of the processing liquid tank 5 is released, and the wafers W, W, ... Are manually or unloading robot (not shown). Thus, the processing liquid tank 5 is automatically taken out from the substrate holding portion and carried to the next step.

However, by passing through such a cleaning step, the wafers W, W, ... Are cleaned in an atmosphere excluding oxygen except when the wafers W are loaded into or unloaded from the processing liquid tank 5. As a result, The contact between the wafers W, W, ... And oxygen is suppressed to a minimum and the formation of a natural oxide film on the wafer surface is effectively prevented.

Further, since the work of loading and unloading the wafers W, W, ... Is carried out without the cleaning liquid in the processing liquid tank 5, the surfaces of these wafers W, W ,. -There is no movement of the liquid interface, and there is no adhesion of contaminants such as particles present at this interface, which has been a problem in the past.

Further, structurally, since it is possible to perform treatment with a plurality of types of cleaning liquids using only a single treatment liquid tank 5, the device itself becomes smaller and simpler than conventional devices of this type, and the product cost is reduced. Is reduced.

Example 2 This example is shown in FIG. 2, and in the constitution of the treatment liquid section 1, the drainage pipe 11b from the drainage valve 11 and the drainage pipe 8 from the upper part of the treatment liquid tank 5 are provided with a switching valve 13c. It is configured to be connected to the switching valve 13a through the above and to introduce nitrogen gas for replacing the cleaning liquid prior to the supply of pure water in the first embodiment.

That is, in the cleaning step (2) of the above-described Example 1 or in each step, the cleaning liquid (HF
Liquid (or BHF liquid), SC-1 liquid or SC-2
Drainage valve 11
Is opened, and nitrogen gas is introduced from the top 5b of the processing liquid tank 5 through the check valve 9a of the inert gas introduction pipe 9.

As a result, the cleaning liquid in the processing liquid tank 5 is pushed downward and discharged from the drain valve 11 to the drain pipe 11b, and the switching valve 13c and the switching valves 13a and 13b.
Via one of the drainage recovery tanks 30a, 3
Recovered to 0b or 30c.

In this way, when the cleaning liquid is completely discharged from the processing liquid tank 5, the supply of nitrogen gas is stopped, the drain valve 11 is closed, and then the liquid supply valve 10d.
Is opened, pure water is supplied into the processing liquid tank 5 through the liquid supply pipe 7, and the washing process with pure water is performed for a predetermined time. Other configurations and operations are similar to those of the first embodiment.

However, by replacing the cleaning liquid by using the inert gas such as nitrogen as described above, each cleaning liquid is not diluted, so that the running cost is further reduced by the amount of dilution in the first embodiment. .

Further, the cleaning liquid collected in the drainage unit 3 is subjected to a predetermined filtration to increase its cleanliness level, and then is refluxed to the post-liquid supply unit 2 to obtain the first embodiment.
It is possible to reuse the cleaning liquid, which was not possible with.

Example 3 This example is shown in FIG. 3, and a depressurizing circuit 42 equipped with an exhaust valve 40 and a vacuum pump 41 was connected to the processing solution tank 5 of the processing solution section 1 to perform the cleaning process in Example 1 ( 2) is configured to be performed in a reduced pressure atmosphere.

That is, the wafers W, W, ...
After being housed and held inside, and sealed, the exhaust valve 40 is opened, the inside of the processing liquid tank 5 is exhausted and decompressed by the vacuum pump 41, and then the exhaust valve 40 is closed again, and subsequently in the first embodiment. The washing step (2) is performed.

By carrying out the cleaning treatment of the wafers W, W, ... Under such a reduced pressure atmosphere, the fine grooves in the surfaces of the wafers W, W, ... Are surely cleaned. Other configurations and operations are similar to those of the first embodiment.

It should be noted that the above-described embodiment is merely a preferred specific example of the present invention, and the present invention should not be construed as being limited thereto, but various design changes are possible within the scope of the gist thereof. Is. For example, the types and numbers of the cleaning liquids used, or the order of treatment with the cleaning liquids are not limited to the illustrated examples, and can be variously changed according to the purpose.

Further, in the illustrated example, a batch type cleaning structure for cleaning a plurality of wafers W at a time is adopted, but the present invention can be applied to a single wafer type structure for cleaning the wafers W one by one. Of course.

[0062]

As described in detail above, according to the present invention,
Wafers are housed and held in a single sealed processing solution tank, and wafers are cleaned while sequentially replacing multiple types of processing solutions with pure water or inert gas, that is, a completely closed system. Since the wafer cleaning process is performed in step 1, various unique effects as listed below can be obtained.

(1) Wafer processing in an atmosphere excluding oxygen is realized, contact between the wafer and oxygen is suppressed to a minimum, and the formation of a natural oxide film on the wafer surface is effectively prevented.

(2) Since the wafer loading / unloading operation can be performed without the cleaning liquid in the processing liquid tank, the boundary surface between the atmosphere and the cleaning liquid (gas-liquid interface) moves on the surface of these wafers. In addition, there is no contamination due to adhesion of contaminants such as particles existing on the boundary surface portion, which has been a problem in the past.

(3) By performing all the wafer processing steps in a single processing liquid tank, the apparatus itself can be simplified and downsized, and an economical processing system can be constructed. Furthermore, it becomes possible to realize a so-called multi-chamber system in which the wet treatment process is combined with the preceding and subsequent processes in a composite manner to form a multi-system.

(4) By processing the wafer in a closed system, it is not necessary to clean the entire apparatus, and in this respect also, the apparatus can be simplified and downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an entire substrate wet cleaning apparatus that is Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a processing liquid section of the entire substrate wet cleaning apparatus that is Embodiment 2 of the present invention.

FIG. 3 is a diagram showing a schematic configuration of a processing liquid section of the entire substrate wet cleaning apparatus that is Embodiment 3 of the present invention.

[Explanation of symbols]

 W Wafer 1 Processing liquid part 2 Liquid supplying part 3 Discharging part 4 Control part 5 Processing liquid tank 5a Processing liquid tank bottom 5b Processing liquid tank top 6 Outer tank 7 Supply pipe 8 Drainage pipe 9 Inert gas introduction pipe 16 Water Supply Pipe 20a to 20d Liquid Supply Tank 23a to 23c Drainage Recovery Tank 42 Pressure Reduction Circuit

Claims (6)

[Claims] 1. A wet processing method for treating a substrate with each of a plurality of types of treatment liquids, wherein the substrate is contained in a single sealed treatment liquid bath, and the plurality of types of treatment liquids are contained in the treatment liquid bath. A method for wet-treating a substrate, characterized in that the substrate is filled and supplied while being sequentially replaced. 2. When replacing the preceding treatment liquid with the treatment liquid that follows, while purging and removing the preceding treatment liquid while filling and supplying deionized water for rinsing with water into the treatment liquid tank, the treatment liquid follows. 2. The wet processing method for a substrate according to claim 1, wherein the pure water is extruded and removed while the processing liquid is being filled and supplied into the processing liquid tank. 3. When replacing the preceding treatment liquid with the treatment liquid which follows, while extruding and eliminating the preceding treatment liquid while filling and supplying an inert gas for substitution into the treatment liquid tank, followed by washing with water. 2. The substrate according to claim 1, wherein after deionized water is filled in and supplied to the treatment liquid tank and a washing process is performed, the deionized water is extruded and eliminated while a subsequent treatment liquid is filled and supplied in the treatment liquid tank. Wet processing method. 4. The method according to claim 1, wherein after the substrate is stored in the processing liquid tank, the inside of the processing liquid tank is temporarily depressurized, and then the processing step with the processing liquid is started. Wet processing method for substrate. 5. In the treatment process using each treatment liquid,
The wet processing method for a substrate according to claim 1, wherein the processing liquid is allowed to flow up. 6. A wet processing apparatus for respectively treating a substrate with a plurality of types of treatment liquids, wherein a single treatment liquid tank that can be sealed and a supply of a plurality of treatment liquids selectively supplied to the treatment liquid tank. And a drainage pipe connected to the top of the processing liquid tank, and a drainage pipe connected to the top of the processing liquid tank. A wet processing apparatus for a substrate, which is provided with a substrate holding portion for directly holding the substrate.