Apparatus and method for supplying liquid

Abstract

The present invention provides a liquid supply unit. The liquid supply unit includes: a tank having an interior space for storing liquid; an inlet line for supplying liquid from a liquid supply source to the interior space, the inlet line having an inlet valve installed on the inlet line; an outlet line for supplying liquid from the tank to a nozzle or recovering liquid back to the tank, the outlet line having an outlet valve installed on the outlet line; a gas supply line for supplying gas to the interior space, the gas supply line having a gas control valve installed on the gas supply line; an exhaust line for exhausting gas from the interior space, the exhaust line having an exhaust valve installed on the exhaust line; a circulation line for circulating the liquid stored in the interior space; and a controller configured to control the liquid supply unit so that the circulation line is pressurized while supplying liquid to the interior space.

Description

Technical Field

[0001] Embodiments of the inventive concepts described herein relate to a liquid supply unit for supplying liquid to an object to be processed and a method of supplying liquid using the liquid supply unit. Background Art

[0002] Contaminants such as particles, organic pollutants, and metallic contaminants remaining on the substrate surface significantly impact the performance and yield of semiconductor devices. Therefore, cleaning processes to remove these contaminants are crucial in semiconductor manufacturing. Substrate cleaning is performed before and after each unit process in semiconductor manufacturing.

[0003] Typically, the substrate cleaning process includes a chemical treatment process using chemicals to remove metal contaminants, organic contaminants, and particles remaining on the substrate, a rinsing process using pure water to remove chemicals remaining on the substrate, and a drying process using nitrogen or supercritical fluid to dry the substrate.

[0004] During chemical processing, a liquid supply unit supplies liquid to the nozzle unit. Typically, the liquid supply unit includes a tank for storing the liquid, a supply line for supplying the liquid from the tank's interior to the nozzle unit, and a recovery line for returning the liquid to the tank's interior after substrate processing. To prevent interruptions in the liquid supply, two or more tanks are provided, and the liquid stored in each tank can be drained through a drain pipe connected to each tank.

[0005] For example, a liquid supply unit supplies liquid to the nozzle unit at a predetermined temperature. Each pipeline is equipped with a heater to provide high-temperature liquid according to each process. Typically, a temperature sensor is located at the discharge end of the heater. Based on the liquid temperature measured by the temperature sensor, the liquid is heated to a predetermined temperature. However, because the heater heats the liquid without considering the temperature of the surface in contact with the liquid, the contact surface of the liquid is heated, resulting in bubbles. These bubbles can cause particle formation problems during subsequent substrate processing. Summary of the Invention

[0006] Embodiments of the inventive concept provide a liquid supply unit and a liquid supply method for preventing liquid from boiling in the liquid supply unit.

[0007] Embodiments of the inventive concept also provide a liquid supply unit and a liquid supply method for minimizing particle generation.

[0008] The technical objectives of the present invention are not limited to the above objectives, and other technical objectives not mentioned will become apparent to those skilled in the art from the following description.

[0009] The present invention provides a liquid supply unit. The liquid supply unit includes a tank having an interior space for storing liquid; an inlet line for supplying liquid from a liquid supply source to the interior space, the inlet line having an inlet valve installed thereon; an outlet line for supplying liquid from the tank to a nozzle or recovering liquid to the tank, the outlet line having an outlet valve installed thereon; a gas supply line for supplying gas to the interior space, the gas supply line having a gas control valve installed thereon; an exhaust line for exhausting gas from the interior space, the exhaust line having an exhaust valve installed thereon; a circulation line for circulating liquid stored in the interior space; and a controller, wherein the controller is configured to control the liquid supply unit so that the circulation line is pressurized when liquid is supplied to the interior space.

[0010] In an embodiment, the controller is further configured to control the gas control valve and the exhaust valve such that when liquid is supplied to the internal space, the internal space is pressurized.

[0011] In an embodiment, the controller is configured to control the gas control valve and the exhaust valve such that when liquid is supplied to the internal space, gas is supplied to the internal space but the exhaust valve is closed.

[0012] In an embodiment, the circulation line includes: a first pump; a first heater, which is used to heat the liquid in the circulation line; and a pressure providing member, which is arranged downstream of the first heater, wherein the pressure required for the liquid to pass through the pressure providing member is set to be higher than the pressure required for the liquid to pass through the first heater.

[0013] In an embodiment, the pressure providing member is configured as a first regulator, and the circulation line further includes a first pressure sensor, which is disposed upstream of the first regulator and senses the liquid pressure in the circulation line. When the liquid pressure in the circulation line is equal to or higher than a predetermined pressure, the first regulator opens to allow liquid to flow.

[0014] In an embodiment, the first heater is provided with a first temperature sensor for measuring the temperature of the contact surface with the liquid, and the first heater is controlled so that the temperature of the contact surface with the liquid measured by the first temperature sensor does not exceed the boiling point of the liquid at a predetermined pressure.

[0015] In an embodiment, when the liquid pressure in the circulation line is equal to or higher than the predetermined pressure, the controller controls the exhaust valve to exhaust gas from the internal space.

[0016] In an embodiment, the outlet pipeline includes: a second pump; a second heater for heating the liquid in the outlet pipeline; a second regulator, the second regulator being configured to be opened to allow the liquid to flow when the pressure upstream of the outlet pipeline is equal to or higher than a predetermined pressure; and a second pressure sensor installed upstream of the second regulator for measuring the pressure of the liquid in the outlet pipeline.

[0017] In an embodiment, the liquid supply unit further includes a supply line branched from the outlet line between the second heater and the second regulator and connected to a nozzle.

[0018] In an embodiment, a second temperature sensor is installed on the second heater, and the second temperature sensor is used to measure the temperature of the contact surface between the second heater and the liquid, and the controller controls the second heater so that the temperature of the contact surface between the second heater and the liquid measured by the second temperature sensor does not exceed the boiling point of the liquid at a predetermined pressure.

[0019] In an embodiment, the tank includes a first tank and a second tank, the circulation line connects the first tank and the second tank, and the controller is configured to control so that when liquid is supplied from the second tank to the nozzle through the inlet line, the liquid is supplied to the first tank through the inlet line, and the liquid in the internal space of the first tank circulates through the circulation line.

[0020] The present invention provides a liquid supply method including supplying liquid to an interior space of one of a first tank and a second tank while pressurizing a circulation line that circulates the liquid in the other interior space of the other of the first tank and the second tank.

[0021] In an embodiment, gas is supplied to the interior space, and the liquid is supplied to the interior space without exhausting gas from the interior space.

[0022] In an embodiment, the circulation line includes: a heater for heating the liquid in the circulation pipe; and a pressure providing member, which is arranged downstream of the heater, and wherein the pressure required for the liquid to pass through the pressure providing member is set to be higher than the pressure required for the liquid to pass through the heater.

[0023] In an embodiment, when the pressure in the circulation line reaches or exceeds a predetermined pressure, the internal space is exhausted.

[0024] In an embodiment, according to the predetermined pressure, the temperature of the heater and the contact surface of the liquid does not exceed the boiling point of the liquid.

[0025] The present invention provides a liquid supply method for substrate processing equipment. The method includes: supplying liquid from the interior space of a second tank through a nozzle while simultaneously supplying the liquid to the interior space of a first tank; and circulating the liquid in the first tank through a circulation line, while pressurizing the circulation line while supplying the liquid.

[0026] In an embodiment, when the liquid is supplied to the interior space of the first tank, gas is supplied to the interior space of the first tank, and gas is not exhausted from the interior space of the first tank.

[0027] In an embodiment, when the pressure of the liquid in the circulation line reaches a predetermined pressure, the liquid is allowed to flow in the circulation line.

[0028] In an embodiment, the heater is provided at the circulation line, and according to the predetermined pressure, the temperature of the contact surface between the heater and the liquid does not exceed the boiling point of the liquid.

[0029] According to an embodiment of the inventive concept, it is possible to prevent liquid from boiling within the liquid supply unit.

[0030] According to embodiments of the inventive concept, generated particles can be minimized.

[0031] Effects of the present inventive concept are not limited to the above-mentioned effects, and effects not mentioned will be clearly understood by those having ordinary skill in the art from this specification and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other objects and features will become apparent from the following description with reference to the following drawings, in which like reference numerals refer to like parts throughout the various figures unless otherwise specified, and in which:

[0033] Figure 1 is a front view schematically illustrating an example of a substrate processing facility provided with a substrate processing apparatus according to an embodiment of the present inventive concept.

[0034] Figure 2 It shows the settings Figure 1 A cross-sectional view of an embodiment of a processing chamber in a substrate processing apparatus.

[0035] Figure 3 Schematic diagram showing a liquid supply unit according to the present invention.

[0036] Figure 4 FIG. 1 is a flowchart illustrating a liquid supply method according to an embodiment of the present inventive concept.

[0037] Figures 5 to 9 Diagrams sequentially illustrating a liquid supply method using a liquid supply unit according to an embodiment of the present inventive concept.

[0038] Figure 10 FIG. 1 is a flow chart illustrating a liquid supplying method according to another embodiment of the present inventive concept.

[0039] Figures 11 to 12 To illustrate another embodiment of the present inventive concept, diagrams are sequentially shown of a liquid supplying method. DETAILED DESCRIPTION

[0040] The present invention is susceptible to various modifications and forms, and specific embodiments thereof will be shown in the accompanying drawings and described in detail. However, the embodiments according to the present invention are not intended to limit the specific disclosed forms, and it should be understood that the present invention includes all conversions, equivalents, and substitutes within the spirit and technical scope of the present invention. In the description of the present invention, when a detailed description of a related known technology may obscure the essence of the present invention, its detailed description may be omitted.

[0041] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, the singular terms "one" and "the / said" also include plural forms, unless the context clearly indicates otherwise. It should also be understood that when used in this specification, the terms "comprising" and "including" used herein refer to the presence of the described features, integral bodies, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integral bodies, steps, operations, elements, components, and / or the above combinations. As used herein, the term "and / or" includes any one or more of the listed related items and all combinations. In addition, the term "exemplary" is intended to refer to an example or illustration.

[0042] It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or portion from another region, layer, or portion. Thus, a first element, component, region, layer, or portion discussed below could be referred to as a second element, component, region, layer, or portion without departing from the teachings of the present invention.

[0043] Figure 1 FIG. 1 is a plan view schematically showing a substrate processing facility 1 according to the present invention. Figure 1The substrate processing facility 1 includes an index module 10 and a process module 20, and the index module 10 includes a load port 120 and a transfer frame 140. The load port 120, the transfer frame 140, and the process module 20 are aligned in sequence. Hereinafter, the direction in which the load port 120, the transfer frame 140, and the process module 20 are aligned is referred to as a first direction 12. When viewed from above, a direction perpendicular to the first direction 12 is referred to as a second direction 14, and a direction perpendicular to a plane including the first and second directions 12, 14 is referred to as a third direction 16.

[0044] The carrier 130 containing the substrate W therein is placed on the load port 120. There are a plurality of load ports 120 and they are sequentially arranged along the second direction 14. Figure 1 Four load ports 120 are provided. However, the number of load ports 120 can be increased or decreased depending on conditions such as the processing efficiency and occupied area of ​​the process module 20. Slots (not shown) for supporting the edges of substrates W are formed on the carrier 130. Multiple slots are provided in the third direction 16, and substrates W are stacked on the carrier while being spaced apart from each other along the third direction 16. A front-opening pod (FOUP) can be used as the carrier 130.

[0045] The processing module 20 includes a buffer unit 220, a transfer chamber 240, and a processing chamber 260. The transfer chamber 240 is arranged so that its longitudinal direction is parallel to the first direction 12. The processing chambers 260 are arranged on one side and the other side of the transfer chamber 240 along the second direction 14. The processing chambers 260 on one side of the transfer chamber 240 and the processing chambers 260 on the other side of the transfer chamber 240 are arranged symmetrically with respect to the transfer chamber 240. Some of the processing chambers 260 are arranged along the longitudinal direction of the transfer chamber 240. In addition, some of the processing chambers 260 are arranged to be stacked on top of each other.

[0046] That is, the processing chambers 260 can be arranged on one side of the transfer chamber 240 in an A×B arrangement (A and B are natural numbers of 1 or greater). Here, "A" is the number of processing chambers 260 arranged in sequence along the first direction 12, and "B" is the number of processing chambers 260 arranged in sequence along the third direction 16. When four or six processing chambers 260 are provided on one side of the transfer chamber 240, the processing chambers 260 can be arranged in a 2×2 or 3×2 arrangement. The number of processing chambers 260 can be increased or decreased. Different from the above description, the processing chambers 260 can be provided on only one side of the transfer chamber 240. In addition, different from the above description, the processing chambers 260 are provided in a single layer on one side or the other side of the transfer chamber 240.

[0047] The buffer unit 220 is disposed between the transfer frame 140 and the transfer chamber 240. The buffer unit 220 provides a space in which the substrate W rests before being transferred between the transfer chamber 240 and the transfer frame 140. The buffer unit 220 is provided with slots (not shown) in which the substrate W is placed, and a plurality of slots (not shown) are provided spaced apart from each other along the third direction 16. The surface of the buffer unit 220 facing the transfer frame 140 and the surface facing the transfer chamber 240 are both open.

[0048] The transfer frame 140 transfers the substrate W between the carrier 130 placed on the load port 120 and the buffer unit 220. The transfer frame 140 is provided with an index rail 142 and an index robot 144. The index rail 142 is arranged so that its longitudinal direction is parallel to the second direction 14. The index robot 144 is mounted on the index rail 142 and moves linearly in the second direction 14 along the index rail 142.

[0049] The indexing robot arm 144 includes a base 144a, a main body 144b, and an indexing arm 144c. The base 144a is mounted to be movable along the indexing track 142. The main body 144b is coupled to the base 144a. The main body 144b is configured to be movable on the base 144a along the third direction 16. In addition, the main body 144b is configured to rotate on the base 144a. The indexing arm 144c is coupled to the main body 144b and configured to be movable forward and backward relative to the main body 144b. Multiple indexing arms 144c are configured to be operated individually. The indexing arms 144c are configured to be stacked and spaced apart from each other along the third direction 16. Some of the indexing arms 144c can be used to transfer substrates W from the processing module 20 to the carrier 130, while other indexing arms 144c can be used to transfer substrates W from the carrier 130 to the processing module 20. This can prevent particles generated from the substrate W before being processed from adhering to the substrate W after being processed during the process of bringing in and taking out the substrate W by the index arm 144 .

[0050] The transfer chamber 240 transfers substrates W between the buffer unit 220 and the processing chamber 260, as well as between the plurality of processing chambers 260. The transfer chamber 240 is provided with a guide rail 242 and a main robot arm 244. The guide rail 242 is arranged so that its longitudinal direction is parallel to the first direction 12. The main robot arm 244 is mounted on the guide rail 242 and moves linearly along the guide rail 242 along the first direction 12. The main robot arm 244 includes a base 244a, a main body 244b, and a main arm 244c. The base 244a is mounted so as to be movable along the guide rail 242. The main body 244b is coupled to the base 244a. The main body 244b is configured to be movable on the base 244a along the third direction 16. In addition, the main body 244b is configured to rotate on the base 244a. The main arm 244c is coupled to the main body 244b and is configured to be movable forward and backward relative to the main body 244b. The plurality of main arms 244 c are configured to be driven individually. The plurality of main arms 244 c are configured to be stacked while being spaced apart from each other along the third direction 16. The main arm 244 c used when transferring a substrate from the buffer unit 220 to the processing chamber 260 may be different from the main arm 244 c used when transferring a substrate from the processing chamber 260 to the buffer unit 220.

[0051] The substrate processing apparatus 300 for performing a cleaning process on the substrate W is disposed in the processing chamber 260. The substrate processing apparatus 300 disposed in each processing chamber 260 may have different structures depending on the type of cleaning process to be performed. Alternatively, the substrate processing apparatus 300 in each processing chamber 260 may have the same structure. Alternatively, the processing chambers 260 may be divided into a plurality of groups, and the substrate processing apparatus 300 disposed in the processing chambers 260 belonging to the same group may have the same structure, while the substrate processing apparatus 300 disposed in the processing chambers 260 belonging to different groups may have different structures.

[0052] For example, when the process chambers 260 are divided into two groups, the process chambers 260 in the first group may be disposed on one side of the transfer chamber 240, and the process chambers 260 in the second group may be disposed on the other side of the transfer chamber 240. Alternatively, the process chambers 260 in the first group may be disposed on one side and the other side of the lower layer of the transfer chamber 240, respectively, and the process chambers 260 in the second group may be disposed on the upper layer of the transfer chamber 240, i.e., above the process chambers 260 in the first group. The process chambers 260 in the first group and the process chambers 260 in the second group may be classified according to the type of chemicals used or the type of cleaning method used.

[0053] Hereinafter, an example of a substrate processing apparatus 300 using a processing liquid to clean a substrate W will be described. Figure 2is a cross-sectional view of an example of a substrate processing apparatus 300. Figure 2 , the substrate processing apparatus 300 includes a housing 320 , a supporting unit 340 , a lifting unit 360 , a nozzle unit 380 , and a liquid supply unit 400 .

[0054] The housing 320 provides a space for performing substrate processing, and its top is open. The housing 320 has an internal recovery container 322, an intermediate recovery container 324, and an external recovery container 326. Each of the recovery containers 322, 324, and 326 recovers a different processing liquid used in the substrate processing process. The internal recovery container 322 is arranged in a ring shape around the support unit 340, the intermediate recovery container 324 is arranged in a ring shape around the internal recovery container 322, and the external recovery container 326 is arranged in a ring shape around the intermediate recovery container 324. The internal space 322a of the internal recovery container 322, the space 324a between the internal recovery container 322 and the intermediate recovery container 324, and the space 326a between the intermediate recovery container 324 and the external recovery container 326 are used as inlets for the processing liquid to flow into the internal recovery container 322, the intermediate recovery container 324, and the external recovery container 326, respectively. Recovery lines 322b, 324b, and 326b are connected to respective recovery containers 322, 324, and 326 and extend downward from their respective bottoms. Each recovery line 322b, 324b, and 326b discharges the process liquid introduced through each recovery container 322, 324, and 326. The discharged process liquid can be reused by an external process liquid regeneration system (not shown).

[0055] The support unit 340 is disposed in the housing 320. During processing, the support unit 340 supports and rotates the substrate. The support unit 340 includes a main body 342, support pins 344, chuck pins 346, and a support shaft 348. When viewed from above, the main body 342 has a generally circular top surface. A support shaft 348, rotatable by a motor 349, is fixedly coupled to the bottom surface of the main body 342. A plurality of support pins 344 are provided. The support pins 344 are disposed on the top edge of the main body 342, spaced a predetermined distance apart from each other, and protrude upward from the main body 342. The support pins 344 are arranged so as to form an annular shape by combining with each other. The support pins 344 support the bottom edge of the substrate, so that the substrate is spaced a predetermined distance apart from the top surface of the main body 342. A plurality of chuck pins 346 are provided. The chuck pins 346 are disposed farther from the center of the main body 342 than the support pins 344. The chuck pins 346 are disposed so as to protrude upward from the main body 342. The chuck pins 346 support one side of the substrate so that the substrate does not deviate laterally from a specific position when the spin head 340 rotates. The chuck pins 346 are arranged to be linearly movable along the radial direction of the main body 342 between a standby position and a supporting position. The standby position is farther from the center of the main body 342 than the supporting position. When the substrate is loaded or unloaded from the spin head 340, the chuck pins 346 are in the standby position. When the substrate is processed, the chuck pins 346 are in the supporting position. In the supporting position, the chuck pins 346 contact the side of the substrate.

[0056] The lifting unit 360 linearly moves the housing 320 in an up / down direction. As the housing 320 moves up and down, the height of the housing 320 relative to the support unit 340 changes. The lifting unit 360 includes a bracket 362, a movable shaft 364, and a driver 366. The bracket 362 is fixedly mounted to the outer wall of the housing 320, and the movable shaft 364, which moves in an up / down direction via the driver 366, is fixedly coupled to the bracket 362. When a substrate W is placed on or lifted from the support unit 340, the housing 320 is lowered, causing the support unit 340 to extend upward from the housing 320. Furthermore, when performing a process, the height of the housing 320 is adjusted according to the type of processing liquid supplied to the substrate W so that the processing liquid can flow into a predetermined recovery container. For example, when processing a substrate with a first processing liquid, the substrate is positioned at a height corresponding to the interior space 322a of the internal recovery container 322. In addition, during the treatment of the substrate with the second and third treatment liquids, the substrate may be located at a height corresponding to the space 324 a between the inner recovery container 322 and the intermediate recovery container 324. Unlike the above description, the elevating unit 360 may move the supporting unit 340 in the up / down direction instead of moving the housing 320.

[0057] During the substrate processing process, the nozzle unit 380 supplies a processing liquid to the substrate W. The nozzle unit 380 includes a nozzle support 382, ​​a nozzle 384, a support shaft 386, and a driver 388. The support shaft 386 is arranged so that its longitudinal direction is in the third direction 16, and the driver 388 is connected to the bottom end of the support shaft 386. The driver 388 rotates and lifts the support shaft 386. The nozzle support 382 is vertically connected to the opposite end of the support shaft 386 and the driver 388. The nozzle 384 is mounted on the bottom surface of one end of the nozzle support 382. The nozzle 384 is moved by the driver 388 to a processing position and a standby position. The processing position is a position in which the nozzle 384 is vertically arranged above the housing 320, while the standby position is a position in which the nozzle 384 is offset from the housing 320 and vertically above the housing 320.

[0058] One or more nozzle units 380 may be provided. When multiple nozzle units 380 are provided, chemicals, cleaning fluids, or organic solvents may be supplied through different nozzle units 380. In an embodiment, the chemical may be an acidic solution such as hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, or the like, or an alkaline solution containing potassium hydroxide, sodium hydroxide, ammonium, or the like. The cleaning fluid may be pure water, and the organic solvent may be a mixture of isopropyl alcohol vapor and an inert gas, or isopropyl alcohol.

[0059] The liquid supply unit 4100 supplies liquid to the nozzle unit 380 . Figure 3 is a diagram illustrating a liquid supply unit 4100 according to the present inventive concept. Figure 3 The liquid supply unit 4100 includes a liquid supply source 4110, a first tank 4120, a second tank 4130, inlet pipelines 4136 and 4135, gas supply pipelines 4129 and 4139, exhaust pipelines 4112 and 4114, an outlet pipeline 4150, drain lines 4181, 4182, a circulation line 4160 and a supply line 4190.

[0060] Liquid supply source 4110 stores liquid for processing and supplies the liquid to first tank 4120 or second tank 4130. In an embodiment, the liquid may be isopropyl alcohol. Alternatively, the liquid may provide different types of chemicals, organic solvents, or the like.

[0061] The first tank 4120 and the second tank 4130 have substantially the same structure. The first tank 4120 and the second tank 4130 store liquid. When liquid is supplied from one of the first tank 4120 or the second tank 4130 to the object 5000 to be processed, liquid exchange is performed in the other tank. In an embodiment, the object 5000 to be processed is a substrate processed in a plurality of processing chambers. For example, any one of the objects 5000 to be processed is Figure 2In the embodiment, a sensor (not shown) is installed in the first tank 4120 and the second tank 4130. The sensor (not shown) detects the residual amount of liquid stored in the inner space of each tank.

[0062] The first tank 4120 and the second tank 4130 may store one liquid supplied from the single liquid supply source 4110. Alternatively, the first liquid and the second liquid supplied from separate liquid supply sources 4110 may be mixed and stored in the first tank 4120 and the second tank 4130.

[0063] Inlet lines 4136 and 4135 may include a first inlet line 4136 and a second inlet pipe 4135, respectively. First inlet line 4136 connects liquid supply source 4110 with first tank 4120. A first inlet valve 4122 is installed at first inlet line 4136 to control whether liquid is supplied from liquid supply source 4110 to first tank 4120 and to control the supply flow rate. Second inlet line 4135 connects liquid supply source 4110 with second tank 4130. A second inlet valve 4132 is installed at second inlet line 4135 to control whether liquid is supplied from liquid supply source 4110 to second inlet pipe 4135 and to control the supply flow rate.

[0064] Gas supply lines 4129 and 4139 supply gas to the first tank 4120 and the second tank 4130. In an embodiment, the gas supply lines 4129 and 4139 include a first gas supply line 4129 and a second gas supply line 4139, respectively. The first gas supply line 4129 supplies gas to the first tank 4120, and the second gas supply line 4139 supplies gas to the second tank 4130. A first gas valve 4128 is installed at the first gas supply line 4129. The first gas valve 4128 controls whether gas is supplied to the first tank 4120 and controls the supply flow rate. A second gas valve 4138 is installed at the second gas supply line 4139. The second gas valve 4138 controls whether gas is supplied to the second tank 4130 and controls the supply flow rate. The gas prevents the liquid stored in each tank 4120 and 4130 from sloshing or volatilizing. In an embodiment, the gas is an inert gas. For example, the gas is nitrogen.

[0065] Exhaust lines 4112 and 4114 exhaust air from the interior spaces of the corresponding tanks 4120 and 4130, respectively. In an embodiment, exhaust lines 4112 and 4114 include a first exhaust line 4112 and a second exhaust line 4114, respectively. First exhaust line 4112 exhausts air from the interior space of first tank 4120. Second exhaust line 4114 exhausts air from the interior space of second tank 4130. A first exhaust valve 4113 is installed on first exhaust line 4112. First exhaust valve 4113 controls whether the interior space of first tank 4120 is exhausted and controls the exhaust flow rate. A second exhaust valve 4116 is installed on second exhaust line 4114. Second exhaust valve 4116 controls whether the interior space of second tank 4130 is exhausted and controls the exhaust flow rate.

[0066] The outlet line 4150 connects the first tank 4120 and the second tank 4130 to the supply line 4190. In addition, the outlet line 4150 recovers the liquid discharged from each of the first tank 4120 and the second tank 4130 to each of the first tank 4120 and the second tank 4130. Hereinafter, a portion of the outlet line 4150 that recovers the liquid discharged from each of the first tank 4120 and the second tank 4130 to the first tank 4120 and the second tank 4130 will be referred to as a recovery line 4170.

[0067] The supply line 4190 supplies liquid to the object to be processed 5000. The outlet line 4150 includes a first outlet line 4151 and a second outlet line 4152. The first outlet line 4151 connects the first tank 4120 and the supply line 4190. A first outlet valve 4126 is installed at the first outlet line 4151 to control the flow rate of liquid supplied from the first tank 4120 to the supply line 4190. The second outlet line 4152 connects the second tank 4130 and the supply line 4190. A second outlet valve 4136 is installed at the second outlet line 4152 to control whether the liquid supplied from the second tank 4130 to the supply line 4190 is supplied and the supply flow rate.

[0068] The drain lines 4181 and 4182 include a first drain line 4181 and a second drain line 4182, respectively. The first drain line 4181 drains the first tank 4120. A first drain valve 4185 is installed on the first drain line 4181 to control whether the liquid drained from the first tank 4120 is drained and to control the drain rate. The second drain line 4182 drains the second tank 4130. A second drain valve 4187 is installed on the second drain line 4182 to control whether the liquid drained from the second tank 4130 is drained and to control the drain rate.

[0069] When the pressure of the liquid in outlet line 4150 is greater than or equal to a predetermined pressure, recovery line 4170 allows liquid to be recovered to each of first tank 4120 and second tank 4130 without being supplied to supply line 4190. Recovery line 4170 recovers liquid from supply line 4190 to the internal space of each of first tank 4120 and second tank 4130. Recovery line 4170 includes a first recovery line 4171 and a second recovery line 4172. First recovery line 4171 recovers liquid to first tank 4120. A first recovery valve 4123 is installed at first recovery line 4171 to control whether to recover liquid recovered from supply line 4190 to first tank 4120 and the recovery rate. Second recovery line 4172 recovers liquid to second tank 4130. A second recovery valve 4133 is installed at the second recovery line pipe 4172 to control whether to recover the liquid recovered from the supply line 4190 to the second tank 4130 and the recovery flow rate.

[0070] In one embodiment, outlet pipeline 4150 is provided with a second pump 4177, a second heater 4175, a second pressure sensor 41701, and a pressure supply member 4173. In one embodiment, second pump 4177, second heater 4175, second pressure sensor 41701, and pressure supply member 4173 are installed in order from upstream to downstream relative to each of tanks 4120 and 4130. In one embodiment, second pump 4177 controls the supply flow rate of liquid by controlling the strokes per minute. Second heater 4175 heats the liquid flowing through outlet pipeline 4150. Second pressure sensor 41701 measures the pressure of the liquid in outlet pipeline 4150.

[0071] The pressure providing member 4173 is arranged downstream of the second heater 4175, and the liquid pressure provided is high enough to pass through the pressure providing member 4173. For example, the pressure providing member 4173 is a member that generates resistance to the flow of liquid in the liquid flow through the pipeline. In an embodiment, the pressure providing member 4173 can be set to any one of a back pressure regulator and a filter. Alternatively, the pressure providing member 4173 can be set to a pipe with a diameter smaller than the diameter of the pipe formed in the outlet pipeline 4150. Therefore, high pressure is required to pass through the pressure providing member 4173. Hereinafter, taking this as an example, the back pressure regulator (second regulator) 4173 will be described as the pressure providing member 4173. The pressure providing member 4173 can be provided as another member that requires high pressure to pass through the pressure providing member 4173.

[0072] The second regulator controls the pressure of the liquid in the outlet line 4150 based on the pressure measured by the second pressure sensor 41701. In an embodiment, the second regulator 4173 is configured as a back pressure regulator. For example, the second regulator 4173 can operate in the same manner as a valve that opens when the pressure upstream exceeds a predetermined pressure to allow the liquid to flow. Therefore, the pressure upstream of the second regulator does not exceed the predetermined pressure. The second temperature sensor 41751 is installed at the second heater 4175. The second temperature sensor 41751 can measure the temperature of the second heater 4175. The second temperature sensor 41751 can measure the temperature of the contact surface (liquid contact) between the second heater 4175 and the liquid in the circulation line. In this case, the contact surface can be the surface of the second heater 4175. For example, the second temperature sensor 41751 can be installed on the surface of the second heater 4175. In an embodiment, the supply line 4190 is connected to a portion of the outlet line 4150 between the second pressure sensor 41701 and the second regulator 4173. Therefore, the liquid may flow to the supply line 4190 instead of flowing to the recovery line 4170 until the pressure of the liquid flowing through the outlet line 4150 reaches a predetermined pressure.

[0073] The circulation line 4160 circulates the liquid stored in the inner spaces of the first tank 4120 and the second tank 4130. The circulation line 4160 has a first line 4161, a second line 4162, a third line 4163, a fourth line 4164, and a common line 4165.

[0074] Common line 4165 connects first line 4161, second line 4162, third line 4163, and fourth line 4164. Liquid flowing through common line 4165 is led back to first tank 4120 via first line 4161, or is led back to second tank 4130 via second line 4162. Similarly, liquid stored in the interior space of first tank 4120 circulates through first line 4161, common line 4165, and third line 4163. Liquid in second tank 4130 circulates through second line 4162, common line 4165, and fourth line 4164.

[0075] A first pump 4167, a first heater 4174, a first pressure sensor 41651, and a pressure providing member 4166 are installed in the common pipeline 4165. In an embodiment, the first pump 4167, the first heater 4174, the first pressure sensor 41651, and the pressure providing member 4166 are installed in order from upstream to downstream relative to each of the tanks 4120 and 4130.

[0076] In an embodiment, the first pump 4167 controls the stroke per minute to adjust the supply flow rate of the liquid. The first heater 4174 heats the liquid flowing through the circulation pipeline 4160. The first pressure sensor 41651 measures the pressure of the liquid flowing through the common pipeline 4165.

[0077] The pressure providing member 4166 is arranged downstream of the first heater 4174 so that the pressure of the liquid passing through the pressure providing member 4166 is set to be higher than the pressure of the liquid passing through the first heater 4174. For example, the pressure providing member 4166 is a member that generates resistance to the flow of liquid in the liquid flow pipe. In an embodiment, the pressure providing member 4166 can be set to any one of a back pressure regulator or a filter. Alternatively, the pressure providing member 4166 can be set to a pipe with a diameter smaller than the pipe diameter forming the common pipeline 4165. Therefore, in order to pass through the pressure providing member 4166, the pressure of the liquid must be increased. Hereinafter, for example, the back pressure regulator (first regulator) 4166 will be described as the pressure providing member 4166. The pressure providing member 4166 can be set to another member that requires high pressure to pass through the pressure providing member 4166. The first regulator 4166 controls the pressure of the liquid in the common pipeline 4165 based on the pressure measured by the first pressure sensor 41651. For example, the first regulator 4166 can operate in the same manner as a valve that opens when the pressure upstream exceeds a predetermined pressure, thereby allowing the liquid to flow. Therefore, the pressure upstream of the first regulator 4166 does not exceed the predetermined pressure. The first temperature sensor 41741 is installed at the first heater 4174. The first temperature sensor 41741 can measure the temperature of the first heater 4174. The first temperature sensor 41741 can measure the temperature of the contact surface where the first heater 4174 and the liquid in the circulation line 4160 come into contact with each other. In this case, the contact surface can be the surface of the first heater 4174. For example, the first temperature sensor 41741 can be installed on the surface of the first heater 4174.

[0078] A first pipeline 4161 is connected to the top surface of the first tank 4120. Liquid passing through a first pump 4167 and a first heater 4174 is introduced into the first tank 4120 via the first pipeline 4161. A first valve 4124 is installed at the first pipeline 4161 to control whether the liquid flowing from the common pipeline 4165 into the first tank 4120 is introduced, and the flow rate thereof. A second pipeline 4162 is connected to the top surface of the second tank 4130. Liquid passing through the first pump 4167, the first heater 4174, and the first pump 4167 flows into the second tank 4130 via the second pipeline 4162. A second valve 4134 is installed at the second pipeline 4162 to control whether the liquid flowing from the common pipeline 4165 into the second tank 4130 is introduced, and the flow rate thereof. A third pipeline 4163 is connected to the bottom surface of the first tank 4120. The liquid in the first tank 4120 is discharged through the third pipeline 4163. A third valve 4125 is installed at the third pipeline 4163 to control whether the liquid supplied from the first tank 4120 to the first heater 4174 is supplied and the supply flow rate. A fourth pipeline 4164 is connected to the bottom surface of the second tank 4130. The liquid stored in the internal space of the second tank 4130 is discharged through the fourth pipeline 4164. A fourth valve 4135 is installed at the fourth pipeline 4164 to control whether the liquid supplied from the second tank 4130 to the first heater 4174 is supplied and the supply flow rate.

[0079] Below, we will refer to Figures 4 to 12 A liquid supply method of the present inventive concept is described. The controller controls the liquid supply unit 4100 to perform the liquid supply method of the present inventive concept. Figure 4 is a flowchart illustrating a liquid supply method according to an embodiment of the inventive concept. Figures 5 and 6 and Figures 8 and 9 The liquid supply method according to the embodiment of the present inventive concept is shown in sequence, and Figure 7 is a graph showing the boiling point of isopropyl alcohol according to pressure.

[0080] Reference Figure 4 First, liquid is supplied to the interior space of the first tank 4120 or the second tank 4130. In an embodiment, while the liquid stored in the interior space of the second tank 4130 is supplied to the nozzle unit 380, the liquid stored in the interior space of the first tank 4120 is circulated through the circulation line 4160, replenishing the liquid to the interior space of the first tank 4120. Similarly, while the liquid stored in the interior space of the first tank 4120 is supplied to the nozzle unit 380, the liquid stored in the interior space of the second tank 4130 can be circulated through the circulation line 4160, replenishing the liquid to the interior space of the second tank 4130. Hereinafter, for example, replenishing the liquid to the interior space of the first tank 4120 will be described.

[0081] like Figure 5 As shown, liquid is supplied from the liquid supply source 4110 to the interior space of the first tank 4120 through the first inlet line 4136. When the liquid supply starts, nitrogen is supplied to the interior space of the first tank 4120 through the first gas supply line 4129, as shown in FIG. Figure 6 As shown. In an embodiment, when nitrogen is supplied to the interior space of the first tank 4120, the interior space may be pressurized. For example, the pressure of the gas supplied to the interior space of the first tank 4120 may be set to be higher than the exhaust pressure exhausted through the first exhaust line 4112. In an embodiment, the first exhaust valve 4113 may be closed when gas is supplied to the interior space. Figure 7 As can be seen, as the pressure of isopropyl alcohol increases, the boiling point also increases. In the present invention, by pressurizing the internal space, the boiling point of the liquid in the liquid supply unit is increased. Therefore, it has the advantage of preventing the liquid from boiling at a relatively low temperature.

[0082] While the liquid is replenished to the inner space of the first tank 4120, the liquid stored in the first tank 4120 is circulated through the circulation line 4160. Figure 8 As shown. While the liquid circulates, the first pressure sensor 41651 continuously measures the pressure of the liquid flowing through the common pipeline 4165. The first regulator 4166 adjusts the pressure in the circulation line 4160 on this basis. For example, the internal space is continuously pressurized by the gas introduced through the gas supply line until the pressure measured by the first pressure sensor 41651 reaches a predetermined pressure. When the liquid pressure measured by the first pressure sensor 41651 reaches a predetermined pressure, the liquid flows through the first regulator 4175. Therefore, in order for the liquid to continue to circulate in the circulation line 4160, the pressure in the circulation line 4160 must reach a predetermined pressure, and for this purpose, the internal space of the tank is continuously pressurized. When the pressure in the circulation line 4160 reaches the predetermined pressure, the pressure upstream of the first regulator 4175 is maintained at the predetermined pressure. To this end, as Figure 8 As shown, the first exhaust valve 4113 is opened. By opening the first exhaust valve 4113, the pressure of the liquid flowing through the circulation line 4160 is maintained at a predetermined pressure.

[0083] As liquid is added to the interior of first tank 4120, the temperature of first heater 4174 is controlled. In an embodiment, the output of first heater 4174 is controlled based on the temperature measured by first temperature sensor 41741. The output of first heater 4174 is adjusted to prevent the isopropyl alcohol flowing through circulation line 4160 from boiling. For example, based on the pressure measured by first pressure sensor 41651, the output of first heater 4174 is adjusted to be less than or equal to the boiling point of isopropyl alcohol. In an embodiment, since the pressure in circulation line 4160 is adjusted to a predetermined pressure, the output of first heater 4174 is adjusted to be equal to or lower than the boiling point of isopropyl alcohol based on the predetermined pressure. In an embodiment, first temperature sensor 41741 is configured to measure the temperature of the contact surface between first heater 4174 and the liquid flowing through common line 4165, for example, the surface of first heater 4174 contacting the liquid flowing through common line 4165. In an embodiment, first temperature sensor 41741 can measure the surface temperature of first heater 4174. Therefore, there is an advantage of preventing the liquid from boiling at the surface of the first heater 4174 that contacts the liquid flowing through the first heater 4174. That is, the present inventive concept has an advantage of preventing the liquid from boiling at the contact surface between the first heater 4174 and the liquid by adjusting the output of the first heater 4174 based on the temperature measured upstream or downstream of the first heater 4174.

[0084] When the liquid replenishment inside the first tank 4120 is completed through the above process, Figure 9 As shown, liquid is supplied to the nozzle unit 380 through the first tank 4120. In this case, the liquid is replenished into the inner space of the second tank 4130, and the liquid stored in the inner space of the second tank 4130 is circulated through the circulation line 4160. When the liquid is replenished into the inner space of the second tank 4130, the above-mentioned liquid supply method is also applicable.

[0085] Figure 10 FIG. 1 is a flow chart illustrating a liquid supply method according to another embodiment of the present invention. Figure 10 , while supplying the liquid, the pressure in the pipeline and the temperature of the surface where the heater and the liquid come into contact with each other can be adjusted. In an embodiment, the surface where the heater and the liquid come into contact with each other can be the surface of the heater. The method for adjusting the pressure in the pipeline and the method for controlling the temperature of the heater surface are the same as described above. In an embodiment, when the liquid is supplied to the nozzle unit 380 through the outlet pipeline 4150, as shown in FIG. Figure 11 As shown, the pressure in the outlet line 4150 is continuously measured by the second pressure sensor 41701. Figure 12As shown, when the liquid pressure measured by second pressure sensor 41701 reaches a predetermined pressure, the liquid flows through second regulator 4173. Therefore, in order for the liquid to be supplied to the recovery line, the pressure in outlet line 4150 must reach the predetermined pressure. To achieve this, the internal space is continuously pressurized. As the liquid is supplied to nozzle unit 380 via outlet line 4150, the temperature of second heater 4175 is adjusted. In an embodiment, the output of second heater 4175 is adjusted based on the temperature measured by second temperature sensor 41751. The output of second heater 4175 is adjusted to prevent the isopropyl alcohol flowing through outlet line 4150 from boiling. For example, based on the pressure measured by second pressure sensor 41701, the output of second heater 4175 is adjusted to be less than or equal to the boiling point of isopropyl alcohol. In an embodiment, since the pressure in outlet line 4150 is adjusted to the predetermined pressure, the output of second heater 4175 is adjusted to be below the boiling point of isopropyl alcohol based on the predetermined pressure. In an embodiment, the second temperature sensor 41751 is configured to measure the temperature of the contact surface between the second heater 4175 and the liquid flowing through the outlet line 4150, for example, the surface of the second heater 4175 in contact with the liquid flowing through the outlet pipe 4150. In an embodiment, the second temperature sensor 41751 can measure the temperature of the surface of the second heater 4175. Therefore, there is an advantage in preventing the liquid flowing through the second heater 4175 and the outlet line 4150 from boiling on the contact surface.

[0086] Effects of the present inventive concept are not limited to the above-mentioned effects, and unmentioned effects may be clearly understood from the description and the accompanying drawings by those skilled in the art to which the present inventive concept pertains.

[0087] Although preferred embodiments of the present invention have been illustrated and described, the present invention is not limited to the specific embodiments described above, and it is noted that those skilled in the art can implement the present invention to varying degrees without departing from the essence of the present invention as claimed in the claims, and that these modifications should not be interpreted separately from the technical spirit or prospects of the present invention.

Claims

1. A liquid supply unit for supplying liquid, comprising: a tank having an interior space for storing the liquid; an inlet pipeline, the inlet pipeline being used to supply the liquid from a liquid supply source to the inner space and having an inlet valve installed on the inlet pipeline; an outlet pipeline for supplying the liquid from the tank to the nozzle or for recovering the liquid to the tank, wherein an outlet valve is installed on the outlet pipeline; a gas supply pipeline, the gas supply pipeline being used to supply gas to the internal space and having a gas control valve installed on the gas supply pipeline; an exhaust pipeline, the exhaust pipeline being used to exhaust air from the internal space and having an exhaust valve installed on the exhaust pipeline; a circulation line, the circulation pipe being used to circulate the liquid stored in the internal space; as well as Controller; The controller is configured to control the liquid supply unit so that the circulation line is pressurized when liquid is supplied to the internal space. 2 . The liquid supply unit according to claim 1 , wherein the controller is further configured to control the gas control valve and the exhaust valve so that the internal space is pressurized when liquid is supplied to the internal space. 3 . The liquid supply unit according to claim 2 , wherein the controller is configured to control the gas control valve and the exhaust valve so that when liquid is supplied to the internal space, the gas is supplied to the internal space but the exhaust valve is closed.

4. The liquid supply unit according to claim 1, wherein the circulation line comprises: First pump; a first heater configured to heat the liquid in the circulation line; and a pressure providing member disposed downstream of the first heater; in, The pressure required for the liquid to pass through the pressure providing member is set to be higher than the pressure required for the liquid to pass through the first heater.

5. The liquid supply unit according to claim 4, wherein the pressure providing member is configured as a first regulator, the circulation line further comprises a first pressure sensor, the first pressure sensor is installed upstream of the first regulator and senses the liquid pressure in the circulation line, and when the liquid pressure in the circulation line becomes equal to or higher than a predetermined pressure, the first regulator opens to allow the liquid to flow.

6. A liquid supply unit according to claim 5, wherein the first heater is provided with a first temperature sensor, the first temperature sensor is used to measure the temperature at the contact surface with the liquid, and the first heater is controlled so that the temperature at the contact surface with the liquid measured by the first temperature sensor does not exceed the boiling point of the liquid at the predetermined pressure. 7 . The liquid supply unit according to claim 5 , wherein when the liquid pressure in the circulation line is equal to or higher than the predetermined pressure, the controller controls the exhaust valve to exhaust gas from the internal space.

8. The liquid supply unit according to claim 1, wherein the outlet line comprises: Second pump; a second heater, the second heater being configured to heat the liquid in the outlet pipeline; a second regulator configured to be opened to allow the liquid to flow when a pressure upstream of the outlet line is equal to or higher than a predetermined pressure; as well as A second pressure sensor is installed upstream of the second regulator to measure the liquid pressure in the outlet pipeline. 9 . The liquid supply unit according to claim 8 , further comprising a supply line branched from the outlet line between the second heater and the second regulator and connected to the nozzle.

10. The liquid supply unit according to claim 8, wherein the second heater is provided with a second temperature sensor for measuring a temperature at a contact surface with the liquid, and The controller controls the second heater so that a temperature at a contact surface with the liquid measured by the second temperature sensor does not exceed a boiling point of the liquid at the predetermined pressure.

11. The liquid supply unit according to any one of claims 1 to 10, wherein the tank includes a first tank and a second tank, the circulation line is connected to the first tank and the second tank, and the controller is configured to control so that when the liquid is supplied from the second tank to the nozzle through the inlet line, the liquid is supplied to the first tank through the inlet line, and the liquid in the internal space of the first tank circulates through the circulation line.

12. A liquid supply method comprising the following steps: supplying liquid to the interior space of one of the first tank or the second tank while pressurizing a circulation line for circulating the liquid in the other interior space of the other of the first tank or the second tank, wherein gas is supplied to the interior space, and liquid is supplied to the interior space without exhausting gas from the interior space.

13. The liquid supply method according to claim 12, wherein the circulation line comprises: a heater, the heater being used to heat the liquid in the circulation line; as well as a pressure providing member disposed downstream of the heater; and The pressure required for the liquid to pass through the pressure providing member is set to be higher than the pressure required for the liquid to pass through the heater. 14 . The liquid supply method according to claim 13 , wherein when the pressure in the circulation line reaches or becomes higher than a predetermined pressure, the gas is exhausted from the internal space. 15 . The liquid supply method according to claim 14 , wherein the temperature of the contact surface of the heater with the liquid is set so as not to exceed the boiling point of the liquid at the predetermined pressure.

16. A liquid supply method using the liquid supply unit according to claim 11, comprising: supplying liquid from the interior space of the second tank through the nozzle while simultaneously supplying the liquid to the interior space of the first tank; as well as The liquid in the first tank is circulated through the circulation line, and the circulation line is pressurized while the liquid supply is performed. 17 . The liquid supply method according to claim 16 , wherein when liquid is supplied to the internal space of the first tank, the gas is supplied to the internal space of the first tank without being exhausted from the internal space of the first tank. 18 . The liquid supply method according to claim 16 , wherein when the pressure of the liquid in the circulation line reaches the predetermined pressure, the liquid is allowed to flow in the circulation line.

19. The liquid supply method according to claim 18, wherein a heater is provided at the circulation line, and a contact surface temperature of the heater and the liquid is set not to exceed a boiling point of the liquid at the predetermined pressure.

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