KR20110082307A - Apparatus for drying a substrate and method of drying a substrate - Google Patents

Abstract

PURPOSE: A substrate drying device and substrate drying method are provided to prevent the concentration of chemical liquid dissolved in supercritical fluid, thereby shortening the time for drying a substrate by using the supercritical fluid. CONSTITUTION: A substrate is dried in a chamber(110). A chemical liquid supply unit(120) supplies chemical liquid onto the substrate to keep the substrate wet. A supercritical fluid supply unit(130) supplies supercritical fluid, whose phase is changed, from a drying gas to the chamber unit. The supercritical fluid supply unit includes a gas supply unit(131), a chemical liquid converting unit(132,133), and a supercritical fluid converting unit(135). A chemical liquid displacing unit(140) supplies the supercritical fluid, whose phase is changed, from the drying gas to the chamber.

Description

Apparatus for drying a substrate and method of drying a substrate}

The present invention relates to a substrate drying apparatus and a substrate drying method, and more particularly, to a substrate drying apparatus and a substrate drying method for drying the substrate using a supercritical fluid to remove the chemical liquid remaining on the substrate.

In general, an isopropyl alcohol (e.g., an isopropyl alcohol) is formed on a substrate treated with a chemical solution such as an etching solution and a cleaning solution used in an etching process of forming a pattern on a substrate using an etching solution and a cleaning process of removing impurities remaining on the substrate using a cleaning solution. The substrate is dried by providing a mixed gas of IPA) and nitrogen (N 2). However, as the pattern formed on the substrate becomes finer, it is difficult to dry the chemical liquid between the patterns when the substrate is dried. Therefore, a drying technique using a supercritical fluid for effectively drying the chemical liquid between the patterns is proposed. In the drying technique using the supercritical fluid, the chemically treated substrate is introduced into a pressure vessel, the liquid carbon dioxide is introduced into the device to replace the chemical liquid on the substrate surface, and the pressure is increased to change the liquid carbon dioxide into a supercritical state. After the critical drying process is performed, the pressure is reduced.

In this case, during the transfer of the substrate into the pressure vessel or when the chemical liquid is naturally dried before the substrate is dried with the supercritical fluid, a lining phenomenon in which the pattern formed on the substrate is inclined may be inclined, or stain may occur on the substrate. Therefore, it is necessary to keep the substrate in the wet state until just before the drying process.

The present invention provides a substrate drying apparatus capable of effectively removing the chemical liquid remaining on the substrate.

The present invention provides a substrate drying method that can effectively remove the chemical liquid remaining on the substrate.

A substrate drying apparatus according to an embodiment of the present invention is a chamber for performing a drying process for drying a substrate, a chemical liquid supply unit for supplying a chemical liquid on the substrate to maintain the wet state of the substrate, to proceed with the drying process A chemical solution for supplying a phase change liquid from the drying gas to the chamber and supplying the phase change liquid from the drying gas to the chamber to replace the chamber with the liquid. A substitution unit. The supercritical fluid supply unit may include a gas supply unit supplying the drying gas, a liquid conversion unit connected to the gas supply unit to phase-change the gas into a liquid, and interconnecting the liquid conversion unit and the chamber; And a supercritical fluid converter configured to phase change liquid into the supercritical fluid and supply the liquid to the chamber. The supercritical fluid converter may be connected to the liquid supply part by a first liquid supply line through which the liquid flows from the liquid converter and the first liquid supply line, and pressurize the liquid to form the supercritical fluid. A pump for varying and interconnecting the pump and the chamber and storing the supercritical fluid. The chemical liquid replacement unit includes a second liquid supply line for supplying the liquid from the liquid conversion unit into the chamber, and a second valve disposed on the second liquid supply line and controlling the flow of the liquid. can do.

The substrate drying apparatus according to an embodiment of the present invention may further include a drain portion communicating with the chamber and discharging the chemical liquid.

In the substrate drying method according to an embodiment of the present invention, after supplying the substrate in the wet state into the chamber, the chemical liquid is supplied onto the substrate to maintain the wet state of the substrate. Subsequently, a drying gas for drying the substrate is phase-changed into a liquid, and a part of the phase-changed liquid is supplied into the chamber and replaced with the liquid from the chemical liquid in the chamber. Thereafter, the remaining of the phase-change liquid is phase-changed into a supercritical fluid, and the substrate is dried by supplying the supercritical fluid into the chamber filled with the liquid. The chemical liquid may be drained from the chamber while supplying the liquid. In addition, when the supercritical fluid is supplied into the chamber, the liquid may be phase-changed into the supercritical state inside the chamber.

The substrate drying apparatus of the present invention replaces the injected anti-drying chemical liquid with a phase change liquid from a drying gas and maintains the liquid in the chamber under a constant pressure and temperature before supplying a supercritical fluid to the chamber. Phase change with supercritical fluid. Therefore, by reducing the drying preventing chemical liquid, the process time for performing the drying process of dissolving the cleaning liquid or etching liquid in the supercritical fluid to dry the substrate. Furthermore, as the flow rate of the chemical liquid decreases, the supercritical fluid can more effectively remove the cleaning liquid or etching liquid from the substrate.

1 is a block diagram illustrating a substrate drying apparatus according to an embodiment of the present invention.
2 is a flowchart illustrating a substrate drying method according to an embodiment of the present invention.

Hereinafter, a substrate drying apparatus and a substrate drying method according to an embodiment of the present invention with reference to the accompanying drawings will be described in detail. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are shown in an enlarged scale than actual for clarity of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a block diagram illustrating a substrate drying apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the substrate drying apparatus 100 according to an embodiment of the present invention includes a chamber 110, a chemical liquid supply unit 120, a supercritical fluid supply unit 130, and a chemical liquid replacement unit 140. do. The substrate drying apparatus 100 removes the chemical liquid remaining on the substrate loaded in the chamber 110 to dry the substrate. The substrate may be a wafer for forming a semiconductor device or a glass substrate for forming a flat panel display device.

The chamber 110 provides a space for performing a drying process for drying the substrate. The chamber 110 includes a lower container (not shown) and an upper container (not shown).

The chemical liquid supply unit 120 maintains the wet state of the substrate loaded in the chamber 110 by supplying the chemical liquid into the chamber 110. The chemical liquid may comprise a material having a relatively low surface tension, for example isopropyl alcohol. As the substrate is kept in a wet state, the substrate may be naturally dried, and the phenomenon of spots, spots, and the like on the substrate may be suppressed.

The supercritical fluid supply unit 130 supplies a supercritical fluid into the chamber 110 to proceed with the drying process. The supercritical fluid has a non-condensing characteristic that does not liquefy even when a pressure above the critical pressure is applied because the distinction between the gas and the liquid is ambiguous as a fluid in a region above the critical temperature Tc and the critical pressure Pc. That is, the physical properties of the supercritical fluid have both liquid and gaseous properties, and thus have the same diffusivity and viscosity as gas and dissolution ability as liquid. Examples of the supercritical fluid include supercritical carbon dioxide, supercritical oxygen, supercritical argon, supercritical krypton, supercritical xenon, supercritical ammonia, and the like. For reference, the supercritical carbon dioxide has a critical temperature of 31 ° C., a critical pressure of 72.8 atm, and a viscosity of 0.03 cP and a surface tension of 0 dyne (S) / cm in the critical region (35 ° C., 75 atm). Density has physical properties of 300 kg / m 3.

In one embodiment of the present invention, the supercritical fluid supply unit 130 may include a gas supply unit 131, a liquid converter 132, 133, and a supercritical fluid converter 135.

The gas supply unit 131 supplies a drying gas for forming the supercritical fluid. For example, the drying gas may include carbon dioxide gas.

The liquid converters 132 and 133 are connected to the gas supply unit 131. The liquid converters 132 and 133 receive the drying gas from the gas supply unit 131 and change the drying gas into a liquid state. For example, the liquid converters 132 and 133 may include a booster 132 and a condenser 133. The booster 132 may increase the pressure of the drying gas. For example, the pressure of the drying gas may be adjusted to 50 to 60 bar. Subsequently, the condenser 133 may cool the drying gas having the increased pressure to be converted into a liquid. Therefore, the fluid state flowing out of the condenser 133 may be a liquid.

The supercritical fluid converter 135 interconnects the liquid converters 132 and 133 and the chamber 110. The supercritical fluid converter 135 phase-changes the liquid flowing out of the liquid converters 132 and 133 into a supercritical fluid. The supercritical fluid converter 135 supplies the supercritical fluid that has been phase-changed to the chamber 110.

In one embodiment of the present invention, the supercritical fluid converter 135 may include a first liquid supply line 135a, a pump 135b, and a tank 135c.

The first liquid supply line 135a interconnects the liquid converters 132 and 133 and the pump 135b. The first liquid supply line 135a provides a flow path for flowing the liquid from the liquid converters 132 and 133 to the pump 135b. The pump 135b is disposed between the liquid converters 132 and 133 and the chamber 135b. The pump 135b converts the liquid into the supercritical fluid by controlling the pressure and temperature of the liquid. The tank 135c stores the supercritical fluid converted by the pump 135b. The tank 135c may be controlled to a pressure and a temperature therein to maintain the state of the supercritical fluid. For example, when the supercritical fluid is carbon dioxide, the tank can be adjusted to a pressure of 300 bar and a temperature of 60 ° C.

In one embodiment of the invention, the supercritical fluid converter 135 is a supercritical fluid supply line (135e) and the supercritical fluid supplying the supercritical fluid between the pump (135b) and the chamber (110) The apparatus may further include a first valve 135d disposed on the critical fluid supply line 135b and controlling the flow of the supercritical fluid discharged from the tank 135c.

The chemical liquid replacement unit 140 supplies the liquid changed in phase from the drying gas into the chamber 110. Therefore, the chemical liquid replacement unit 140 replaces the chemical liquid inside the chamber with the phase-changed liquid.

In one embodiment of the present invention, the chemical liquid replacement unit 140 is a second liquid supply line 141 for supplying the phase-changed liquid into the chamber 110 from the liquid conversion unit 132, 133 and It is disposed on the second liquid supply line 141, may include a second valve 143 for controlling the flow of the liquid. The second valve 143 is opened after the chemical liquid is supplied into the chamber 110 and is supplied to the chamber 110 by supplying the phase-changed liquid to the chamber 110 to the liquid converters 132 and 133. ) To prevent drying of the substrate mounted therein. Then, when the chamber 110 is filled with the phase change liquid, the second valve 143 may be closed.

The substrate drying apparatus 100 according to the exemplary embodiment of the present invention may further include a first drain part 150. The first drain unit 150 drains the chemical liquid to the outside of the chamber 110 in order to replace the chemical liquid with the phase-changed liquid. The first drain part 150 may include, for example, an injector 151. The injector 151 may drain the chemical liquid into the chamber 110.

The substrate drying apparatus 110 according to an embodiment of the present invention may further include a second drain 160. The second drain 160 may dry the substrate using the supercritical fluid and then discharge the supercritical fluid in which the chemical liquid is dissolved from the chamber 110. The second drain 160 is disposed on the discharge line 161, the discharge line 161, and the chemical liquid is disposed on the separator 163 and the discharge line from the supercritical fluid and discharged from the chamber. It may include a third valve 162 for controlling the flow of the supercritical fluid to be. The liquid phase-changed by the separator 163 may be mixed with the chemical liquid flowing out of the first drain part 150 and drained into the mixing tank 170.

The substrate drying apparatus according to the embodiments of the present invention substitutes a phase change liquid from a drying gas into a phase change liquid and supplies the phase change liquid into the chamber under a constant pressure and temperature before supplying a supercritical fluid to the chamber. Maintaining allows the liquid to phase change into a supercritical fluid. Therefore, by reducing the drying preventing chemical liquid, the process time for performing the drying process of dissolving the cleaning liquid or etching liquid in the supercritical fluid to dry the substrate. Furthermore, as the flow rate of the chemical liquid decreases, the supercritical fluid can more effectively remove the cleaning liquid or etching liquid from the substrate.

2 is a flowchart illustrating a substrate drying method according to an embodiment of the present invention.

1 and 2, in the substrate drying method according to an embodiment of the present invention, first, the substrate in which the wet state is maintained is supplied into the chamber 110 (S110). The substrate may be transferred by, for example, a wet transfer method coated with isopropyl alcohol. Therefore, the inclination of the pattern formed on the substrate during substrate transfer can be suppressed.

Subsequently, the chemical liquid is supplied onto the substrate mounted in the chamber 110 to maintain the wet state of the substrate (S120). The chemical liquid may include a material having a relatively low surface tension such as, for example, isopropyl alcohol.

Then, the drying gas for drying the substrate to change the phase of the liquid (S130). The liquid phase change may be, for example, a carbon dioxide liquid. In order to phase change the drying gas into a phase-changed liquid, a booster 132 and a condenser 133 for adjusting the pressure and temperature of the drying gas may be used.

Some of the phase-changed liquid is supplied to the chamber 110 to replace the inside of the chamber with the liquid from the chemical liquid (S140). Therefore, since the solubility in which the chemical liquid is subsequently dissolved in the supercritical fluid supplied into the chamber 110 is limited, the process time for dissolving the chemical liquid in the supercritical fluid can be suppressed. In addition, the chemical liquid may be replaced with the phase-changed liquid and the chemical liquid may be discharged to the first drain part 150. Therefore, the chemical liquid remaining in the chamber 110 is reduced. In addition, the phase change liquid may be phase change into a supercritical fluid by controlling the temperature and pressure inside the chamber. Accordingly, as the supercritical fluid is subsequently supplied into the chamber, the phase-changed liquid is converted into the supercritical fluid in the chamber 110 so that the cleaning or etching liquid remaining on the substrate in the chamber can be more effectively removed. .

Subsequently, the remaining phase of the phase-changed liquid is phase-changed into a supercritical fluid (S150). The pump 135b may be used to phase-change the phase-changed liquid into a supercritical fluid.

Subsequently, the phase-change supercritical fluid may be supplied into the chamber 110 to dry the substrate.

In the substrate drying method as described above, a part of the phase change liquid from the drying gas is supplied to the chamber to replace the previously supplied chemical liquid, and the part of the phase change liquid is changed into a supercritical fluid and supplied into the chamber. The concentration of the chemical liquid dissolved in the supercritical fluid can be suppressed from increasing. Therefore, the drying process for drying the substrate using the supercritical fluid can be saved in time.

As described above, in the substrate drying apparatus and the substrate drying method according to the embodiments of the present invention, the anti-drying chemical liquid injected before supplying a supercritical fluid to the chamber is replaced with a phase change liquid from a drying gas and the phase changed liquid. Phase can be transformed into a supercritical fluid by maintaining in the chamber under constant pressure and temperature. Therefore, by reducing the drying preventing chemical liquid, the process time for performing the drying process of dissolving the cleaning liquid or etching liquid in the supercritical fluid to dry the substrate. Furthermore, as the flow rate of the chemical liquid decreases, the supercritical fluid can more effectively remove the cleaning liquid or etching liquid from the substrate. The substrate drying apparatus and the substrate drying method according to embodiments of the present invention may be applied to a drying apparatus for performing a drying process of a flat panel display device and a drying process of a semiconductor device.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

100 substrate drying apparatus 110 chamber
120: chemical liquid supply unit 130: supercritical fluid supply unit
131: gas supply unit 133: liquid conversion unit
135: supercritical fluid converter 135a: first liquid supply line
135b: Pump 135c: Tank
135d: first valve 140: liquid supply part
141: first liquid supply line 143: second valve
150: first drain portion 160: second drain portion
170: mixing tank

Claims (8)

A chamber for performing a drying process for drying the substrate;
A chemical liquid supply unit supplying a chemical liquid on the substrate to maintain the wet state of the substrate;
A supercritical fluid supply unit supplying a supercritical fluid, which is phase-changed from a drying gas, to the chamber unit to proceed with the drying process; And
And a chemical liquid replacement unit for supplying the liquid phase-changed from the drying gas to the chamber to replace the chamber with the liquid from the chemical liquid. The method of claim 1, wherein the supercritical fluid supply unit,
A gas supply unit supplying the drying gas;
A liquid converter connected to the gas supply to change the gas into a liquid; And
And a supercritical fluid converting unit interconnecting the liquid converting unit and the chamber and supplying the liquid to the supercritical fluid. The method of claim 2, wherein the supercritical fluid converter,
A first liquid supply line through which the liquid flows from the liquid converter;
A pump connected to the liquid supply part by the first liquid supply line and pressurizing the liquid to change the phase into the supercritical fluid; And
And a tank interconnecting said pump and said chamber and storing said supercritical fluid. The liquid crystal replacement unit of claim 2, wherein the chemical liquid replacement unit is disposed on the second liquid supply line and the second liquid supply line to supply the liquid from the liquid conversion unit to the inside of the chamber, and to control the flow of the liquid. A substrate drying apparatus comprising two valves. The substrate drying apparatus of claim 1, further comprising a drain portion communicating with the chamber and discharging the chemical liquid. Supplying the wet substrate to the chamber;
Supplying a chemical liquid on the substrate to maintain the wet state of the substrate;
Phase changing a drying gas for drying the substrate into a liquid;
Supplying a portion of the phase change liquid into the chamber to replace the liquid with the liquid in the chamber;
Phase changing the remainder of the phase change liquid into a supercritical fluid; And
Supplying said supercritical fluid into said chamber filled with said liquid to dry said substrate. 7. The method of claim 6, further comprising draining the chemical liquid from the chamber while simultaneously supplying the liquid. 7. The method of claim 6, wherein supplying a supercritical fluid into the chamber further comprises phase shifting the liquid into a supercritical state within the chamber.

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