CN113539900B

CN113539900B - Method and apparatus for drying wafers

Info

Publication number: CN113539900B
Application number: CN202110804184.7A
Authority: CN
Inventors: 杨永刚
Original assignee: Yangtze Memory Technologies Co Ltd
Current assignee: Yangtze Memory Technologies Co Ltd
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2023-09-19
Anticipated expiration: 2041-07-16
Also published as: CN113539900A

Abstract

The application provides a method and a device for drying a wafer. The method comprises the following steps: mixing deionized water and solute to obtain a solution with a surface tension lower than that of the deionized water; forming a gas layer on the solution; soaking the wafer by using the solution; and moving the wafer from the solution into the gas layer via a gas-liquid interface between the solution and the gas layer.

Description

Method and apparatus for drying wafers

Technical Field

The present application relates to the field of cleaning equipment, and more particularly, to a method and apparatus for drying wafers.

Background

In the fabrication of semiconductor devices, wafers are often wet cleaned. The wafer also needs to be dried after wet cleaning. And water marks and the like on the surface of the wafer are avoided, so that the influence on the subsequent process is avoided.

Typical ways to dry the wafer are spin-drying, isopropyl alcohol (IPA) vapor drying, and the like. Yet another way to dry the wafer is to pull the wafer immersed in deionized water out of the water and into isopropyl alcohol vapor above the water. When the wafer is pulled out of the water surface of the deionized water, water attached to the wafer surface is left under the action of surface tension, and the wafer can be further dried in isopropanol vapor.

Since the semiconductor structure fabricated on the wafer is very fine, for example, the three-dimensional memory is fabricated by removing the sacrificial layer of the stacked structure and leaving the oxide layer thin. These thin oxide layers can bend under surface tension and thus affect subsequent gate layer filling. As another example, semiconductor structures have high aspect ratio structures or structures with fragile materials that may even be damaged by the surface tension of water.

Disclosure of Invention

Embodiments of the present application provide a method for drying a wafer, the method comprising: mixing deionized water and solute to obtain a solution with a surface tension lower than that of the deionized water; forming a gas layer on the solution; soaking the wafer by using the solution; and moving the wafer from the solution into the gas layer via a gas-liquid interface between the solution and the gas layer.

In one embodiment, the method further comprises: and staying the wafer in the gas layer for a preset time, wherein the gas pressure of the gas layer is lower than the standard atmospheric pressure.

In one embodiment, the gas layer comprises: nitrogen and the solute.

In one embodiment, the concentration of the solute in the solution is controlled by controlling the flow rate of the deionized water and the flow rate of the solute.

In one embodiment, the solute comprises an organic compound.

In one embodiment, the solute is selected from at least one of isopropanol, n-propanol, ethanol, and methanol.

In one embodiment, the solute is present in the solution at a mass ratio of less than or equal to 30%.

In a second aspect, embodiments of the present application provide an apparatus for drying a wafer, the apparatus comprising a tank having an interior cavity; a drying tank including a recess in communication with the interior cavity and adapted to receive the wafer; a liquid supply device communicated with the groove for conveying a solution into the groove, wherein the solution is obtained by mixing deionized water and solute, and the surface tension of the solution is lower than that of the deionized water; and a gas supply device in communication with the lumen to deliver gas to the lumen for forming a gas layer on the solution and having a gas-liquid interface with the solution.

In one embodiment, the apparatus further comprises: and the air extracting device is used for extracting air from the inner cavity so that the air pressure of the air layer is lower than the standard atmospheric pressure.

In one embodiment, the gas supply is for delivering nitrogen carrying the solute.

In one embodiment, the air supply device includes: the steam tank comprises a solute space, and an air inlet and an air outlet which are positioned at the upper part of the solute space; the lower part of the solute space is suitable for containing the solute, the air inlet is suitable for introducing nitrogen for carrying the solute in a gaseous state, and the air outlet is communicated with the inner cavity.

In one embodiment, the liquid supply device comprises: a first liquid supply pipe, one end of which is in fluid communication with the groove, and the other end of which is used for receiving the deionized water; and a second liquid supply tube in fluid communication with the recess through the first liquid supply tube for supplying the solute to the recess through the first liquid supply tube.

In one embodiment, the first liquid supply pipe comprises a first control valve for controlling the flow rate of the first liquid supply pipe; the second liquid supply pipe comprises a second control valve for controlling the flow rate of the second liquid supply pipe; and wherein the second liquid supply pipe and the first liquid supply pipe are communicated between the first control valve and one end of the first liquid supply pipe, or the second liquid supply pipe and the first liquid supply pipe are communicated between the first control valve and the other end of the first liquid supply pipe.

In one embodiment, the solute comprises an organic compound.

The method and the device for drying the wafer can reduce the surface tension of the liquid at the gas-liquid interface, thereby reducing the influence of the surface tension of the liquid level on the semiconductor structure on the wafer. The cleaned wafer is clean and has no water mark, and the cleaning effect of each place is better on the wafer with larger area. And the semiconductor structure on the cleaned wafer has good integrity.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the accompanying drawings in which:

fig. 1 shows a schematic block diagram of an apparatus for drying a wafer according to an embodiment of the present application;

FIG. 2 is a flow diagram of a method for drying a wafer according to an embodiment of the present application; and

fig. 3 to 5 illustrate process steps for drying a wafer according to an embodiment of the present application.

Detailed Description

For a better understanding of the application, various aspects of the application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the application and is not intended to limit the scope of the application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Thus, a first conduit discussed below may also be referred to as a second conduit without departing from the teachings of the present application. And vice versa.

In the drawings, the thickness, size, and shape of the components have been slightly adjusted for convenience of description. The figures are merely examples and are not drawn to scale. For example, the dimensions of the cavity and the dimensions of the recess are not to scale in actual production. As used herein, the terms "about," "approximately," and the like are used as terms of a table approximation, not as terms of a table degree, and are intended to account for inherent deviations in measured or calculated values that will be recognized by one of ordinary skill in the art.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "containing," and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features that are listed, the entire listed feature is modified instead of modifying a separate element in the list. Furthermore, when describing embodiments of the application, use of "may" means "one or more embodiments of the application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including engineering and technical terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. In addition, unless explicitly defined or contradicted by context, the particular steps included in the methods described herein need not be limited to the order described, but may be performed in any order or in parallel. The application will be described in detail below with reference to the drawings in connection with embodiments.

Referring to fig. 1, there is shown an apparatus for drying a wafer according to the present application. The apparatus 100 includes: tank 110, drying tank 120, liquid supply device 130, and gas supply device 140.

The can 110 has an interior cavity 111, the interior cavity 111 being illustratively a sealed cavity formed by a can bottom, a can wall, and a sealing cover. In some embodiments, the canister 110 may also be in communication with other sealing structures, and the interior cavity 111 may include only, for example, a canister wall and a sealing cover. The sealing cover is connected with the tank wall and can be opened and closed for taking and placing wafers. The cavity 111 is adapted to form a gas layer therein to prevent water marks from being generated when the wafer is exposed to air.

A drying tank 120 may be disposed within the interior cavity 111, the drying tank 120 including a recess 121 adapted to receive a wafer. In some embodiments, the drying trough 120 is connected to the tank 110 and the recess 121 is in communication with the interior cavity 111. The recess 121 is used to hold a solution and to hold a wafer to be processed, which may be completely immersed in the solution held in the recess 121.

Illustratively, wafers to be processed are placed in and removed from the recess 121 by the movable apparatus 122, and wafers may enter the cavity 111 from the recess 121. Illustratively, the drying trough 120 may be configured as an overflow trough.

The liquid supply 130 communicates with the recess 121 to deliver the solution into the recess 121. The solution is obtained by mixing deionized water and solute. The surface tension is lower than that of deionized water. The liquid supply device 130 may include a deionized water generation device, which may remove impurities in the form of ions in the pure water based on, for example, an RO reverse osmosis process, and thus may obtain deionized water. The surface tension of the solute is lower than that of deionized water, and then the surface tension of the solution after the solute is mixed with the deionized water is lower than that of the deionized water. The deionized water may have a surface tension of approximately 72.7mN/m, and the solution may have a surface tension of less than 70mN/m, and further, the solution may have a surface tension of less than 60mN/m, for example, 50mN/m.

The gas supply 140 communicates with the inner chamber 111 to deliver gas to the inner chamber 111. The gas is used to form a gas layer above the solution, the gas layer being in contact with the solution and having a gas-liquid interface therebetween. Illustratively, the gas is a dry gas. Further, the temperature of the gas may be higher than room temperature, for example 50 degrees.

In use, the apparatus 100 can be used by introducing a solution, which is obtained by mixing deionized water and a solute and has a surface tension lower than that of deionized water, into the recess 121 of the drying chamber 120 via the liquid supply device 130. The wafer is immersed in the solution filled recess 121; and can deliver gas for forming a gas layer having a gas-liquid interface with the solution on the solution to the inner cavity 111 through the gas supply device 140; the wafer is then moved out of the solution by the movable apparatus 122, specifically, the wafer is moved from the solution into the gas layer via a gas-liquid interface between the solution and the gas layer. The gas supplied from the gas supply device 140 may further dry the solution attached to the surface of the wafer.

The device for drying the wafer provided by the embodiment can construct a structure with a gas layer at the upper part and a solution at the lower part in the space, and the surface tension of the solution is small. The wafer is adapted to enter the gas layer from a solution in a posture in which the crystal plane is perpendicular to the gas-liquid interface. The device for drying the wafer can reduce the surface tension of liquid at the gas-liquid interface, further lighten the influence of the surface tension of the liquid surface on the semiconductor structure on the wafer, and can avoid water marks left on the surface of the wafer after the wafer is thoroughly cleaned.

In one embodiment, referring to fig. 1, the apparatus 100 further comprises: and an air extraction device 150. The evacuation device 150 is used to evacuate the lumen 111 to a gas pressure below normal atmospheric pressure. Specifically, the device 100 may be used by first pumping air out of the cavity 111 by the air pumping device 150 and then injecting a small amount of air into the cavity 111 by the air supply device 140. Since the inner chamber 111 is ensured to be a sealed environment, a low-pressure gas layer can be formed in the inner chamber 111. The apparatus 100 for drying wafers moves the wafers into the interior cavity 111 during use. When the gas layer has a low pressure state, the solution on the surface of the wafer can be volatilized more quickly and thoroughly, which further reduces the water mark on the surface of the wafer. In addition, the air extractor 150 can extract the air and the volatile solute and vapor from the wafer delivered by the air supply device 140 out of the cavity 111, so as to maintain the air pressure in the cavity 111 in a stable state.

In one embodiment, referring to fig. 1, the liquid supply apparatus 130 includes a first liquid supply pipe 131 and a second liquid supply pipe 132. One end of the first liquid supply pipe 131 is in fluid communication with the recess 121, and the other end is for receiving deionized water. Illustratively, the other end of the first supply tube 131 is in fluid communication with a deionized water producing device. One end of the second liquid supply pipe 132 is in fluid communication with the groove 121 through the first liquid supply pipe 131 for supplying solute to the groove 121 through the first liquid supply pipe 131. Illustratively, the other end of the second supply tube 132 may be in fluid communication with a solute supply device. The liquid supply device 130 may mix the solute and the deionized water together, and the mixed solution may enter the groove 121 through the first liquid supply pipe 131.

Illustratively, the solute comprises an organic compound. The organic compound can avoid generating ions when being mixed with deionized water, and the solution avoids having ions, thereby improving the cleaning effect and avoiding influencing the semiconductor structure of the wafer.

In an exemplary embodiment, the solute is selected from at least one of isopropanol, n-propanol, ethanol, and methanol. For example, the solute is isopropanol, the surface tension of the isopropanol is 22-23 mN/m, and the isopropanol has better intersolubility with deionized water. Further, after the solutes are mutually dissolved with deionized water, the surface tension of the obtained solution is low.

In one embodiment, referring to fig. 1, the first liquid supply pipe 131 includes a first control valve 133 for controlling the on-off state of the first liquid supply pipe 131, and further controlling the flow rate of the liquid conveyed in the first liquid supply pipe 131.

In one embodiment, referring to fig. 1, the second liquid supply pipe 132 includes a second control valve 134 for controlling the on-off state of the second liquid supply pipe 132, and further controlling the flow rate of the solute conveyed in the second liquid supply pipe 132. By the cooperation of the first liquid supply pipe 131 and the second liquid supply pipe 132, the ratio of each component of the solution in the first liquid supply pipe 131 can be controlled. Further, when the flow rates of deionized water and solute are constant, the concentration of solute in the solution may be relatively stable. As the flow rates of deionized water and solutes vary, the concentration of solutes in the solution can also vary.

Illustratively, the second supply tube 132 communicates with the first supply tube 131 at an inflow end of the first control valve 133. Illustratively, the second supply tube 132 may be in communication with the first supply tube 131 at an outflow end of the first control valve 133.

In one embodiment, gas supply 140 is used to deliver nitrogen carrying solutes. As the liquid on the wafer surface is continuously volatilized, the wafer surface gradually comes into direct contact with the gas layer. Nitrogen is an inert gas that protects the wafer surface from changes such as oxidation. After the surface of the wafer contacts with the solute in the gas layer, the concentration of the solute on the surface of the wafer is further improved, and the drying effect can be further enhanced.

In one embodiment, referring to fig. 1, the gas supply device 140 includes: the vapor tank 141 includes a solute space 142, and an air inlet 143 and an air outlet 144 located at an upper portion of the solute space 142.

The lower portion of the solute space 142 is adapted to hold a solute, and in particular, the lower portion of the solute space 142 may hold a solute in a liquid state. Meanwhile, the liquid solute may volatilize the gaseous solute toward the upper portion of the solute space 142. Illustratively, a low pressure may be present within solute space 142.

The gas inlet 143 is adapted to be fed with an inert gas, such as nitrogen. Specifically, the gas inlet 143 may be in fluid communication with a gas source or gas pump, thereby passing nitrogen supplied by the gas source or gas pump into the solute space 142. The nitrogen is used to carry gaseous solutes which then enter the chamber 111 through the outlet 144 which is in communication with the chamber 111.

Illustratively, the portion of the air outlet 144 that enters the interior cavity 111 may include at least two nozzles, each positioned above the drying bath 120 and may be higher than the wafer from which the solution has been removed, which may be used to blow air against the wafer surface.

Fig. 2 is a flow diagram of a method for drying a wafer according to an embodiment of the present application.

Referring to fig. 2, a method 2000 provided by an embodiment of the present application includes the following steps:

in step S201, deionized water and solute are mixed to obtain a solution with a surface tension lower than that of deionized water.

In step S202, a gas layer is formed on the solution.

In step S203, the wafer is soaked with the solution.

In step S204, the wafer is moved from the solution into the gas layer via a gas-liquid interface between the solution and the gas layer.

In an exemplary embodiment, the method 2000 further includes step S205 of staying the wafer in the gas layer for a predetermined time. Illustratively, the gas layer has a gas pressure below normal atmospheric pressure.

The method 2000 for drying a wafer provided by the present application may be implemented using the apparatus 100 for drying a wafer described above.

The steps of method 2000 are described in further detail below with reference to fig. 3-5.

Step S201

Referring to fig. 3, the solution 1 obtained after step S201 includes deionized water and a solute. The surface tension of the resulting solution after adding the solute to deionized water is lower. Specifically, deionized water is mixed with a liquid solute and a relatively uniform solution is obtained.

In one embodiment, the solute comprises an organic compound. For example, the solute is at least one selected from the group consisting of isopropanol, n-propanol, ethanol and methanol.

In one embodiment, the solute is present in the solution at a mass ratio of less than or equal to 30%. The mass ratio of solute to deionized water may be, for example, 3:7,2:8 or 1:9. the quality ratio of the solute is controlled, so that the cleaning performance of the solution on the wafer can be maintained. The water content of the liquid infiltrated on the surface of the wafer is reduced, and the water content of the liquid remained on the surface of the wafer is also lower after the wafer is taken out of the solution later.

In one embodiment, the concentration of the solute in the solution is controlled by controlling the flow of deionized water and the flow of the solute.

Step S202

Referring to fig. 3, a gas layer 2 may be formed through step S202. The gas layer 2 is arranged on the solution 1 and can be in direct contact with the solution 1, and the interface between the solution 1 and the gas layer 2 is a gas-liquid interface 12.

Illustratively, referring to FIG. 1, a gas layer 2 is formed within the cavity 111. The gas layer 2 may also comprise the upper space of the recess 121. The gas of the gas layer 2 is supplied by the gas supply means 140 and can be sucked away from the inner cavity 111 by the gas suction means 150. Illustratively, the gas layer 2 may be flowing when the method 2000 is performed. In an exemplary embodiment, the gas layer 2 includes: nitrogen and solutes.

Step S203

The wafer 3 is immersed in the solution 1.

Illustratively, the wafer 3 is immersed in the solution 1 for a first predetermined time to allow the solution 1 to infiltrate into the semiconductor structure of the wafer 3 and infiltrate the surface of the wafer 3. Illustratively, the solution 1 may impregnate the wafer 3 in conjunction with ultrasonic vibration; illustratively, referring to fig. 1, solution 1 is in recess 121 and is flowing while immersing wafer 3. For example, the solution 1 enters the recess 121 through the solution supplying means 130 and overflows from the upper edge of the drying tank 120. Substances attached to the surface of the wafer 1 can be washed away by the solution 1. Meanwhile, a liquid film based on the solution 1 can be attached to the surface of the wafer 1 under the action of surface tension, van der Waals force and the like.

Step S204

Referring to fig. 4, in the process of moving the wafer 3 from the solution 1 to the gas layer 2 via the gas-liquid interface 12 between the solution 1 and the gas layer 2, a part of the wafer 3 enters the gas layer 2 and another part is also located in the solution 1, and the liquid film attached to the surface of the wafer 3 moves upward with the wafer 3 and is brought up to a certain height. Illustratively, the movement speed of the wafer 3 is slow.

In other embodiments, the gas-liquid interface 12 is lowered by slowly draining the solution 2. And further the gas layer 2 is lowered. This relatively allows the wafer 3 to pass from the solution 1 into the gas layer 2.

In the process of the movement of the wafer 3 relative to the gas-liquid interface 12, the intersection of the gas-liquid interface 12, the solid-liquid interface and the solid-gas interface is changed continuously. Specifically, the gas layer 2 continuously wets the surface of the wafer 3, and the liquid film on the surface of the wafer 3 is continuously "sucked back" under the action of the surface tension and gravity of the solution 1.

While the gas continuously wets the wafer 3 and the solution 1 is continuously stripped, the semiconductor structure of the wafer 3 is pulled by the solution 1. Because the solution 1 provided by the application contains solute, the surface tension of the solution 1 is reduced, and the pulling force applied to the semiconductor structure is also reduced. Some high aspect ratio, low strength semiconductor structures in wafer 3 can remain more complete. Further, the solute (gaseous state) is also contained in the gas layer 2, and thus the surface tension difference with the solution 1 can be reduced.

Step S205

The wafer is held in the gas layer for a second predetermined time.

Illustratively, as the mass ratio of solute in solution 1 increases, the surface tension of solution 1 continuously decreases. In the process of separating the wafer 3 from the solution 1, the peeling efficiency of the liquid film on the surface of the wafer 3 may decrease with the decrease of the surface tension of the solution 1, i.e., the residual liquid on the surface of the wafer 3 may increase. The ratio of solute in the liquid remaining on the surface of the wafer 3 is also increased. When the concentration of the solute increases, the solute with low surface tension can "squeeze" water molecules on the surface of the wafer 3, and can promote deionized water to separate from the surface of the wafer.

As shown in fig. 5, the wafer 3 stays in the gas layer 2 while step S205 is performed. Specifically, referring to fig. 1, a gas supply 140 supplies low pressure gas to dry deionized water and solutes on the surface of the wafer 3. Illustratively, the gas pressure of the gas layer 2 is below normal atmospheric pressure, which facilitates the evaporation of the liquid from the surface of the wafer 3. Illustratively, the gas layer 2 comprises nitrogen and a solute. The solute may be an organic compound such as isopropyl alcohol, n-propyl alcohol, ethanol, and methanol. Illustratively, the volume ratio of solute in the gas layer 2 is less than 10%, so that the wafer 3 can be separated more easily when the solution 1 is separated from the wafer 3 and enters the gas layer 2, and the volatilization efficiency of residual liquid on the surface of the wafer 3 can be ensured.

If the deionized water and solute components remain on the surface of the wafer 3, a final good drying effect can be achieved by prolonging the drying time.

According to the method for drying the wafer, provided by the embodiment of the application, the wafer is soaked by the solution with lower surface tension, so that the stress on the gas-liquid interface where the wafer passes through from the solution to the gas layer is reduced, and the risk of damage to the semiconductor structure caused by large stress on the gas-liquid interface in the lifting process of the wafer is reduced. Further, better drying effect can be achieved by controlling the concentration of solute in the solution, the concentration of solute in the gas layer or by extending the drying time.

The above description is only illustrative of the preferred embodiments of the present application and of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the application is not limited to the specific combination of the above technical features, but also encompasses other technical solutions which may be formed by any combination of the above technical features or their equivalents without departing from the spirit of the application. Such as the above-mentioned features and the technical features of the present application (but not limited to) having similar functions are replaced with each other.

Claims

1. A method for drying a wafer, comprising:

mixing deionized water and solute to obtain a solution with a surface tension lower than that of the deionized water;

forming a gas layer on the solution;

soaking the wafer by using the solution; and

moving the wafer from the solution into the gas layer via a gas-liquid interface between the solution and the gas layer;

the method further comprises the steps of:

and staying the wafer in the gas layer for a preset time, wherein the gas pressure of the gas layer is lower than the standard atmospheric pressure.

2. The method of claim 1, wherein the gas layer comprises: nitrogen and the solute.

3. The method of claim 1, wherein the concentration of the solute in the solution is controlled by controlling the flow of deionized water and the flow of the solute.

4. A method according to any one of claims 1 to 3, wherein the solute comprises an organic compound.

5. The method of claim 4, wherein the solute is selected from at least one of isopropanol, n-propanol, ethanol, and methanol.

6. The method of claim 4, wherein the solute is present in the solution at a mass ratio of less than or equal to 30%.

7. An apparatus for drying a wafer, comprising:

a tank body having an inner cavity;

a drying tank including a recess in communication with the interior cavity and adapted to receive the wafer;

a liquid supply device communicated with the groove for conveying a solution into the groove, wherein the solution is obtained by mixing deionized water and solute, and the surface tension of the solution is lower than that of the deionized water; and

a gas supply device in communication with the lumen to deliver gas to the lumen for forming a gas layer on the solution and having a gas-liquid interface with the solution;

the apparatus further comprises: and the air extracting device is used for extracting air from the inner cavity so that the air pressure of the air layer is lower than the standard atmospheric pressure.

8. The apparatus of claim 7, wherein the gas supply is configured to deliver nitrogen carrying the solute.

9. The apparatus of claim 8, wherein the air supply means comprises: the steam tank comprises a solute space, and an air inlet and an air outlet which are positioned at the upper part of the solute space;

the lower part of the solute space is suitable for containing the solute, the air inlet is suitable for introducing nitrogen for carrying the solute in a gaseous state, and the air outlet is communicated with the inner cavity.

10. The apparatus of claim 7, wherein the liquid supply means comprises:

a first liquid supply pipe, one end of which is in fluid communication with the groove, and the other end of which is used for receiving the deionized water; and

a second liquid supply tube in fluid communication with the recess through the first liquid supply tube for supplying the solute to the recess through the first liquid supply tube.

11. The apparatus of claim 10, wherein the first supply tube comprises a first control valve for controlling a flow rate of the first supply tube;

the second liquid supply pipe comprises a second control valve for controlling the flow rate of the second liquid supply pipe; and

the second liquid supply pipe is communicated with the first liquid supply pipe between the first control valve and one end of the first liquid supply pipe, or the second liquid supply pipe is communicated with the first liquid supply pipe between the first control valve and the other end of the first liquid supply pipe.

12. The apparatus of any one of claims 7 to 11, wherein the solute comprises an organic compound.

13. The apparatus of claim 12, wherein the solute is selected from at least one of isopropanol, n-propanol, ethanol, and methanol.